Minor tweaks

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

.devcontainer/Dockerfile

@@ -0,0 +1,29 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.187.0/containers/python-3/.devcontainer/base.Dockerfile
+
+# [Choice] Python version: 3, 3.9, 3.8, 3.7, 3.6
+ARG VARIANT="3.9.0-buster"
+FROM python:${VARIANT}
+
+# [Option] Install Node.js
+ARG INSTALL_NODE="true"
+ARG NODE_VERSION="lts/*"
+RUN if [ "${INSTALL_NODE}" = "true" ]; then su vscode -c "umask 0002 && . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1"; fi
+
+# [Optional] If your pip requirements rarely change, uncomment this section to add them to the image.
+# COPY requirements.txt /tmp/pip-tmp/
+# RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
+#    && rm -rf /tmp/pip-tmp
+
+# [Optional] Uncomment this section to install additional OS packages.
+# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
+
+# [Optional] Uncomment this line to install global node packages.
+# RUN su vscode -c "source /usr/local/share/nvm/nvm.sh && npm install -g <your-package-here>" 2>&1
+
+
+RUN pip install -U https://github.com/platformio/platformio-core/archive/develop.zip
+RUN platformio update
+# To get the test platforms
+RUN pip install PyYaml
+#ENV PATH /code/buildroot/bin/:/code/buildroot/tests/:${PATH}

.devcontainer/devcontainer.json

@@ -0,0 +1,51 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.187.0/containers/python-3
+{
+  "name": "Python 3",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "context": "..",
+    "args": {
+      // Update 'VARIANT' to pick a Python version: 3, 3.6, 3.7, 3.8, 3.9
+      "VARIANT": "3.9.0-buster",
+      // Options
+      "INSTALL_NODE": "false",
+      "NODE_VERSION": "lts/*"
+    }
+  },
+
+  // Set *default* container specific settings.json values on container create.
+  "settings": {
+    "python.pythonPath": "/usr/local/bin/python",
+    "python.languageServer": "Pylance",
+    "python.linting.enabled": true,
+    "python.linting.pylintEnabled": true,
+    "python.formatting.autopep8Path": "/usr/local/py-utils/bin/autopep8",
+    "python.formatting.blackPath": "/usr/local/py-utils/bin/black",
+    "python.formatting.yapfPath": "/usr/local/py-utils/bin/yapf",
+    "python.linting.banditPath": "/usr/local/py-utils/bin/bandit",
+    "python.linting.flake8Path": "/usr/local/py-utils/bin/flake8",
+    "python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
+    "python.linting.pycodestylePath": "/usr/local/py-utils/bin/pycodestyle",
+    "python.linting.pydocstylePath": "/usr/local/py-utils/bin/pydocstyle",
+    "python.linting.pylintPath": "/usr/local/py-utils/bin/pylint"
+  },
+
+  // Add the IDs of extensions you want installed when the container is created.
+  "extensions": [
+    "ms-python.python",
+    "ms-python.vscode-pylance",
+    "platformio.platformio-ide",
+    "marlinfirmware.auto-build",
+    "editorconfig.editorconfig"
+  ],
+
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  // "forwardPorts": [],
+
+  // Use 'postCreateCommand' to run commands after the container is created.
+  // "postCreateCommand": "pip3 install --user -r requirements.txt",
+
+  // Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+  // "remoteUser": "vscode"
+}

.github/workflows/check-pr.yml

@@ -29,6 +29,6 @@ jobs:
 
           Please redo this PR starting with the `bugfix-2.1.x` branch and be careful to target `bugfix-2.1.x` when resubmitting the PR. Patches may also target `bugfix-2.0.x` if they are specifically for 2.0.9.x.
 
-          It may help to set your fork's default branch to `bugfix-2.0.x`.
+          It may help to set your fork's default branch to `bugfix-2.1.x`.
 
           See [this page](https://marlinfw.org/docs/development/getting_started_pull_requests.html) for full instructions.

.github/workflows/test-builds.yml

@@ -44,6 +44,7 @@ jobs:
         - teensy31
         - teensy35
         - teensy41
+        - SAMD21_minitronics20
         - SAMD51_grandcentral_m4
         - PANDA_PI_V29
 

.gitignore

@@ -21,7 +21,8 @@
 
 # Generated files
 _Version.h
-bdf2u8g
+bdf2u8g.exe
+genpages.exe
 marlin_config.json
 mczip.h
 *.gen

Marlin/Makefile

@@ -307,20 +307,22 @@ else ifeq ($(HARDWARE_MOTHERBOARD),1154)
 else ifeq ($(HARDWARE_MOTHERBOARD),1155)
 # Tenlog D3 Hero IDEX printer
 else ifeq ($(HARDWARE_MOTHERBOARD),1156)
-# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Fan, Bed)
+# Tenlog D3,5,6 Pro IDEX printers
 else ifeq ($(HARDWARE_MOTHERBOARD),1157)
-# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Hotend2, Bed)
+# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Fan, Bed)
 else ifeq ($(HARDWARE_MOTHERBOARD),1158)
-# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend, Fan0, Fan1, Bed)
+# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Hotend2, Bed)
 else ifeq ($(HARDWARE_MOTHERBOARD),1159)
-# Longer LK1 PRO / Alfawise U20 Pro (PRO version)
+# Ramps S 1.2 by Sakul.cz (Power outputs: Hotend, Fan0, Fan1, Bed)
 else ifeq ($(HARDWARE_MOTHERBOARD),1160)
-# Longer LKx PRO / Alfawise Uxx Pro (PRO version)
+# Longer LK1 PRO / Alfawise U20 Pro (PRO version)
 else ifeq ($(HARDWARE_MOTHERBOARD),1161)
-# Zonestar zrib V5.3 (Chinese RAMPS replica)
+# Longer LKx PRO / Alfawise Uxx Pro (PRO version)
 else ifeq ($(HARDWARE_MOTHERBOARD),1162)
-# Pxmalion Core I3
+# Zonestar zrib V5.3 (Chinese RAMPS replica)
 else ifeq ($(HARDWARE_MOTHERBOARD),1163)
+# Pxmalion Core I3
+else ifeq ($(HARDWARE_MOTHERBOARD),1164)
 
 #
 # RAMBo and derivatives

Marlin/Version.h

@@ -1,6 +1,6 @@
 /**
  * Marlin 3D Printer Firmware
- * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
  * Based on Sprinter and grbl.
  * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
@@ -28,25 +28,25 @@
 /**
  * Marlin release version identifier
  */
-//#define SHORT_BUILD_VERSION "bugfix-2.1.x"
+#define SHORT_BUILD_VERSION "bugfix-2.1.x_R01"
 
 /**
  * Verbose version identifier which should contain a reference to the location
  * from where the binary was downloaded or the source code was compiled.
  */
-//#define DETAILED_BUILD_VERSION SHORT_BUILD_VERSION
+#define DETAILED_BUILD_VERSION SHORT_BUILD_VERSION " TM3D"
 
 /**
  * The STRING_DISTRIBUTION_DATE represents when the binary file was built,
  * here we define this default string as the date where the latest release
  * version was tagged.
  */
-//#define STRING_DISTRIBUTION_DATE "2022-10-18"
+#define STRING_DISTRIBUTION_DATE "2023-03-10"
 
 /**
  * Defines a generic printer name to be output to the LCD after booting Marlin.
  */
-//#define MACHINE_NAME "3D Printer"
+#define MACHINE_NAME "TM3D Raptor"
 
 /**
  * The SOURCE_CODE_URL is the location where users will find the Marlin Source
@@ -54,7 +54,7 @@
  * has a distinct Github fork— the Source Code URL should just be the main
  * Marlin repository.
  */
-//#define SOURCE_CODE_URL "github.com/MarlinFirmware/Marlin"
+#define SOURCE_CODE_URL "https://github.com/InsanityAutomation/Marlin/tree/Raptor_2.0.X"
 
 /**
  * Default generic printer UUID.
@@ -65,7 +65,7 @@
  * The WEBSITE_URL is the location where users can get more information such as
  * documentation about a specific Marlin release.
  */
-//#define WEBSITE_URL "marlinfw.org"
+#define WEBSITE_URL "tinymachines3d.com"
 
 /**
  * Set the vendor info the serial USB interface, if changable

Marlin/_Bootscreen.h

@@ -0,0 +1,105 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * Custom Bitmap for splashscreen
+ *
+ * You may use one of the following tools to generate the C++ bitmap array from
+ * a black and white image:
+ *
+ *  - http://www.marlinfw.org/tools/u8glib/converter.html
+ *  - http://www.digole.com/tools/PicturetoC_Hex_converter.php
+ */
+
+#define CUSTOM_BOOTSCREEN_TIMEOUT   2500
+#define CUSTOM_BOOTSCREEN_BMPWIDTH  128
+#define CUSTOM_BOOTSCREEN_BMPHEIGHT 64
+
+const unsigned char custom_start_bmp[] PROGMEM = {
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFD, 0x55, 0x55, 0x55, 0x55, 0x55, 0x5F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFD, 0x00, 0x00, 0x07, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFE, 0x07, 0xC0, 0x05, 0x55, 0x55, 0x55, 0x55, 0x55, 0x5F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFC, 0x0A, 0x20, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFE, 0x14, 0x10, 0x05, 0x00, 0x00, 0x07, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFC, 0x28, 0x08, 0x06, 0x07, 0xC0, 0x05, 0x55, 0x55, 0x55, 0x55, 0x55, 0x5F, 0xFF, 0xFF, 0xFF,
+0xFE, 0x54, 0x04, 0x04, 0x0A, 0x20, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F, 0xFF, 0xFF, 0xFF,
+0xFC, 0x60, 0x04, 0x06, 0x14, 0x10, 0x05, 0x00, 0x00, 0x07, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFE, 0x50, 0x04, 0x04, 0x28, 0x08, 0x06, 0x07, 0xC0, 0x05, 0x55, 0x55, 0x55, 0x55, 0x55, 0x5F,
+0xFC, 0x60, 0x04, 0x06, 0x54, 0x04, 0x04, 0x0A, 0x20, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F,
+0xFE, 0x54, 0x04, 0x1C, 0x60, 0x04, 0x06, 0x14, 0x10, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F,
+0xFC, 0x28, 0x08, 0x2E, 0x50, 0x04, 0x04, 0x28, 0x08, 0x06, 0x07, 0xC0, 0x00, 0x01, 0xF0, 0x3F,
+0xFE, 0x14, 0x10, 0x54, 0x60, 0x04, 0x06, 0x54, 0x04, 0x04, 0x0A, 0x20, 0x00, 0x02, 0x08, 0x1F,
+0xFC, 0x0A, 0x20, 0x66, 0x54, 0x04, 0x1C, 0x60, 0x04, 0x06, 0x14, 0x10, 0x00, 0x05, 0x04, 0x3F,
+0xFE, 0x07, 0xC0, 0x54, 0x28, 0x08, 0x2E, 0x50, 0x04, 0x04, 0x28, 0x08, 0x00, 0x0A, 0x02, 0x1F,
+0xFC, 0x00, 0x00, 0x2E, 0x14, 0x10, 0x54, 0x60, 0x04, 0x06, 0x54, 0x04, 0x00, 0x15, 0x01, 0x3F,
+0xFE, 0x00, 0x00, 0x1C, 0x0A, 0x20, 0x66, 0x54, 0x04, 0x1C, 0x60, 0x04, 0x00, 0x18, 0x01, 0x1F,
+0xFC, 0x00, 0x00, 0x06, 0x07, 0xC0, 0x54, 0x28, 0x08, 0x2E, 0x50, 0x04, 0x00, 0x14, 0x01, 0x3F,
+0xFE, 0x00, 0x00, 0x04, 0x00, 0x00, 0x2E, 0x14, 0x10, 0x54, 0x60, 0x04, 0x00, 0x18, 0x01, 0x1F,
+0xFC, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x1C, 0x0A, 0x20, 0x66, 0x54, 0x04, 0x1C, 0x15, 0x01, 0x3F,
+0xFE, 0xD5, 0x55, 0x54, 0x00, 0x00, 0x06, 0x07, 0xC0, 0x54, 0x28, 0x08, 0x2A, 0x0A, 0x02, 0x1F,
+0xFC, 0x84, 0x10, 0x46, 0x00, 0x00, 0x04, 0x00, 0x00, 0x2E, 0x14, 0x10, 0x51, 0x05, 0x04, 0x3F,
+0xFE, 0xC4, 0x10, 0x44, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x1C, 0x0A, 0x20, 0x61, 0x02, 0x88, 0x1F,
+0xFC, 0x84, 0x10, 0x46, 0xD5, 0x55, 0x54, 0x00, 0x00, 0x06, 0x07, 0xC0, 0x51, 0x01, 0xF0, 0x3F,
+0xFE, 0x84, 0x10, 0x44, 0x84, 0x10, 0x46, 0x00, 0x00, 0x04, 0x00, 0x00, 0x2A, 0x00, 0x00, 0x1F,
+0xFC, 0xC4, 0x10, 0x46, 0xC4, 0x10, 0x44, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x1C, 0x00, 0x00, 0x3F,
+0xFE, 0x84, 0x10, 0x44, 0x84, 0x10, 0x46, 0xD5, 0x55, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F,
+0xFC, 0xD5, 0x55, 0x56, 0x84, 0x10, 0x44, 0x84, 0x10, 0x46, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F,
+0xFC, 0xFF, 0xFF, 0xFC, 0xC4, 0x10, 0x46, 0xC4, 0x10, 0x44, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x9F,
+0xFE, 0x00, 0x00, 0x06, 0x84, 0x10, 0x44, 0x84, 0x10, 0x46, 0xD5, 0x55, 0x55, 0x55, 0x55, 0xBF,
+0xFD, 0x55, 0x55, 0x54, 0xD5, 0x55, 0x56, 0x84, 0x10, 0x44, 0x84, 0x10, 0x41, 0x04, 0x10, 0x9F,
+0xFF, 0xFF, 0xFF, 0xFC, 0xFF, 0xFF, 0xFC, 0xC4, 0x10, 0x46, 0xC4, 0x10, 0x41, 0x04, 0x11, 0xBF,
+0xFF, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x06, 0x84, 0x10, 0x44, 0x84, 0x10, 0x41, 0x04, 0x10, 0x9F,
+0xFF, 0xFF, 0xFF, 0xFD, 0x55, 0x55, 0x54, 0xD5, 0x55, 0x56, 0x84, 0x10, 0x41, 0x04, 0x10, 0x9F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0xFF, 0xFF, 0xFC, 0xC4, 0x10, 0x41, 0x04, 0x11, 0xBF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x06, 0x84, 0x10, 0x41, 0x04, 0x10, 0x9F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFD, 0x55, 0x55, 0x54, 0xD5, 0x55, 0x55, 0x55, 0x55, 0xBF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x9F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFD, 0x55, 0x55, 0x55, 0x55, 0x55, 0x5F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xE0, 0x2E, 0xFB, 0x7D, 0xFB, 0xFB, 0xCF, 0xC1, 0xDF, 0xBB, 0x3E, 0xC0, 0xE1, 0xFE, 0x3C, 0x1F,
+0xFD, 0xEE, 0x7B, 0x39, 0xF9, 0xF3, 0xCF, 0x9E, 0xDF, 0xBB, 0x3E, 0xDF, 0xDE, 0xFC, 0xDD, 0xE7,
+0xFD, 0xEE, 0x3B, 0xBB, 0xF9, 0xEB, 0xD7, 0xBF, 0x5F, 0xBB, 0x5E, 0xDF, 0xDE, 0xFD, 0xED, 0xF7,
+0xFD, 0xEE, 0xBB, 0xD3, 0xFA, 0xEB, 0xB7, 0x3F, 0xDF, 0xBB, 0x4E, 0xDF, 0xDF, 0xFF, 0xCD, 0xF3,
+0xFD, 0xEE, 0xDB, 0xC7, 0xFA, 0xEB, 0xBB, 0x7F, 0xC0, 0x3B, 0x6E, 0xC0, 0xE3, 0xFF, 0x1D, 0xF3,
+0xFD, 0xEE, 0xCB, 0xEF, 0xFA, 0xDB, 0xBB, 0x7F, 0xDF, 0xBB, 0x66, 0xDF, 0xF8, 0xFF, 0xCD, 0xF3,
+0xFD, 0xEE, 0xEB, 0xEF, 0xFB, 0x5B, 0x03, 0x3F, 0x5F, 0xBB, 0x76, 0xDF, 0xFE, 0x7F, 0xED, 0xF3,
+0xFD, 0xEE, 0xF3, 0xEF, 0xFB, 0x5B, 0x79, 0xBE, 0xDF, 0xBB, 0x7A, 0xDF, 0xDE, 0x7D, 0xED, 0xF7,
+0xFD, 0xEE, 0xF3, 0xEF, 0xFB, 0xBA, 0xFD, 0x9E, 0xDF, 0xBB, 0x7C, 0xDF, 0xDE, 0xFD, 0xCD, 0xE7,
+0xFD, 0xEE, 0xFB, 0xEF, 0xFB, 0xBA, 0xFD, 0xC1, 0xDF, 0xBB, 0x7E, 0xC0, 0xE0, 0xFE, 0x1C, 0x1F,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+};
+
+
+

Marlin/_Statusscreen.h

@@ -0,0 +1,74 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * Custom Status Screen bitmap
+ *
+ * Place this file in the root with your configuration files
+ * and enable CUSTOM_STATUS_SCREEN_IMAGE in Configuration.h.
+ *
+ * Use the Marlin Bitmap Converter to make your own:
+ * http://marlinfw.org/tools/u8glib/converter.html
+ */
+
+//
+// Status Screen Logo bitmap
+//
+#define STATUS_LOGO_Y            3
+#define STATUS_LOGO_WIDTH       24
+
+const unsigned char status_logo_bmp[] PROGMEM = {
+  B11111111,B11111111,B11111111,
+  B10000000,B00000000,B00000001,
+  B10001110,B00000000,B11100001,
+  B10011111,B00000001,B11110001,
+  B10010011,B10000001,B00111001,
+  B10011111,B10000001,B11111001,
+  B10011111,B10000001,B11111001,
+  B10011111,B10111001,B11111001,
+  B10001111,B00101000,B11110001,
+  B10000000,B00111000,B00000001,
+  B10000000,B00000000,B00000001,
+  B10011111,B11111111,B11111001,
+  B10010001,B01110100,B10011001,
+  B10011011,B00000110,B10101001,
+  B10011011,B01010100,B10101001,
+  B10011011,B01010110,B10101001,
+  B10011011,B01010100,B10011001,
+  B10011111,B11111111,B11111001,
+  B11111111,B11111111,B11111111
+};
+
+//
+// Use default bitmaps
+//
+#define STATUS_HOTEND_ANIM
+#define STATUS_BED_ANIM
+#if HOTENDS < 2
+  #define STATUS_LOGO_X          8
+  #define STATUS_HEATERS_X      40
+  #define STATUS_BED_X          72
+#else
+  #define STATUS_LOGO_X          0
+  #define STATUS_HEATERS_X      32
+  #define STATUS_BED_X          80
+#endif

Marlin/config.ini

@@ -95,10 +95,10 @@ invert_y_dir                             = true
 invert_z_dir                             = false
 invert_e0_dir                            = false
 
-invert_e_step_pin                        = false
-invert_x_step_pin                        = false
-invert_y_step_pin                        = false
-invert_z_step_pin                        = false
+step_state_e                             = HIGH
+step_state_x                             = HIGH
+step_state_y                             = HIGH
+step_state_z                             = HIGH
 
 disable_x                                = false
 disable_y                                = false
@@ -178,7 +178,7 @@ autotemp_oldweight                       = 0.98
 bed_check_interval                       = 5000
 default_stepper_deactive_time            = 120
 default_volumetric_extruder_limit        = 0.00
-disable_inactive_e                       = true
+disable_inactive_extruder                = true
 disable_inactive_x                       = true
 disable_inactive_y                       = true
 disable_inactive_z                       = true

Marlin/src/HAL/AVR/HAL.h

@@ -32,6 +32,7 @@
   #include <HardwareSerial.h>
 #else
   #include "MarlinSerial.h"
+  #define BOARD_NO_NATIVE_USB
 #endif
 
 #include <stdint.h>
@@ -106,36 +107,36 @@ typedef Servo hal_servo_t;
 
   #define MYSERIAL1 TERN(BLUETOOTH, btSerial, MSerial0)
 #else
-  #if !WITHIN(SERIAL_PORT, -1, 3)
-    #error "SERIAL_PORT must be from 0 to 3, or -1 for USB Serial."
+  #if !WITHIN(SERIAL_PORT, 0, 3)
+    #error "SERIAL_PORT must be from 0 to 3."
   #endif
   #define MYSERIAL1 customizedSerial1
 
   #ifdef SERIAL_PORT_2
-    #if !WITHIN(SERIAL_PORT_2, -1, 3)
-      #error "SERIAL_PORT_2 must be from 0 to 3, or -1 for USB Serial."
+    #if !WITHIN(SERIAL_PORT_2, 0, 3)
+      #error "SERIAL_PORT_2 must be from 0 to 3."
     #endif
     #define MYSERIAL2 customizedSerial2
   #endif
 
   #ifdef SERIAL_PORT_3
-    #if !WITHIN(SERIAL_PORT_3, -1, 3)
-      #error "SERIAL_PORT_3 must be from 0 to 3, or -1 for USB Serial."
+    #if !WITHIN(SERIAL_PORT_3, 0, 3)
+      #error "SERIAL_PORT_3 must be from 0 to 3."
     #endif
     #define MYSERIAL3 customizedSerial3
   #endif
 #endif
 
 #ifdef MMU2_SERIAL_PORT
-  #if !WITHIN(MMU2_SERIAL_PORT, -1, 3)
-    #error "MMU2_SERIAL_PORT must be from 0 to 3, or -1 for USB Serial."
+  #if !WITHIN(MMU2_SERIAL_PORT, 0, 3)
+    #error "MMU2_SERIAL_PORT must be from 0 to 3"
   #endif
   #define MMU2_SERIAL mmuSerial
 #endif
 
 #ifdef LCD_SERIAL_PORT
-  #if !WITHIN(LCD_SERIAL_PORT, -1, 3)
-    #error "LCD_SERIAL_PORT must be from 0 to 3, or -1 for USB Serial."
+  #if !WITHIN(LCD_SERIAL_PORT, 0, 3)
+    #error "LCD_SERIAL_PORT must be from 0 to 3."
   #endif
   #define LCD_SERIAL lcdSerial
   #if HAS_DGUS_LCD

Marlin/src/HAL/AVR/MarlinSerial.h

@@ -34,6 +34,7 @@
 #include <WString.h>
 
 #include "../../inc/MarlinConfigPre.h"
+#include "../../core/types.h"
 #include "../../core/serial_hook.h"
 
 #ifndef SERIAL_PORT
@@ -138,10 +139,6 @@
 
   #define BYTE 0
 
-  // Templated type selector
-  template<bool b, typename T, typename F> struct TypeSelector { typedef T type;} ;
-  template<typename T, typename F> struct TypeSelector<false, T, F> { typedef F type; };
-
   template<typename Cfg>
   class MarlinSerial {
   protected:
@@ -164,7 +161,7 @@
     static constexpr B_U2Xx<Cfg::PORT>   B_U2X   = 0;
 
     // Base size of type on buffer size
-    typedef typename TypeSelector<(Cfg::RX_SIZE>256), uint16_t, uint8_t>::type ring_buffer_pos_t;
+    typedef uvalue_t(Cfg::RX_SIZE - 1) ring_buffer_pos_t;
 
     struct ring_buffer_r {
       volatile ring_buffer_pos_t head, tail;

Marlin/src/HAL/AVR/fast_pwm.cpp

@@ -23,6 +23,10 @@
 
 #include "../../inc/MarlinConfig.h"
 
+//#define DEBUG_AVR_FAST_PWM
+#define DEBUG_OUT ENABLED(DEBUG_AVR_FAST_PWM)
+#include "../../core/debug_out.h"
+
 struct Timer {
   volatile uint8_t* TCCRnQ[3];  // max 3 TCCR registers per timer
   volatile uint16_t* OCRnQ[3];  // max 3 OCR registers per timer
@@ -108,12 +112,15 @@ const Timer get_pwm_timer(const pin_t pin) {
 }
 
 void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
+  DEBUG_ECHOLNPGM("set_pwm_frequency(pin=", pin, ", freq=", f_desired, ")");
   const Timer timer = get_pwm_timer(pin);
   if (timer.isProtected || !timer.isPWM) return; // Don't proceed if protected timer or not recognized
 
   const bool is_timer2 = timer.n == 2;
   const uint16_t maxtop = is_timer2 ? 0xFF : 0xFFFF;
 
+  DEBUG_ECHOLNPGM("maxtop=", maxtop);
+
   uint16_t res = 0xFF;        // resolution (TOP value)
   uint8_t j = CS_NONE;        // prescaler index
   uint8_t wgm = WGM_PWM_PC_8; // waveform generation mode
@@ -121,23 +128,29 @@ void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
   // Calculating the prescaler and resolution to use to achieve closest frequency
   if (f_desired != 0) {
     constexpr uint16_t prescaler[] = { 1, 8, (32), 64, (128), 256, 1024 };  // (*) are Timer 2 only
-    uint16_t f = (F_CPU) / (2 * 1024 * maxtop) + 1;           // Start with the lowest non-zero frequency achievable (1 or 31)
+    uint16_t f = (F_CPU) / (uint32_t(maxtop) << 11) + 1;      // Start with the lowest non-zero frequency achievable (for 16MHz, 1 or 31)
 
+    DEBUG_ECHOLNPGM("f=", f);
+    DEBUG_ECHOLNPGM("(prescaler loop)");
     LOOP_L_N(i, COUNT(prescaler)) {                           // Loop through all prescaler values
-      const uint16_t p = prescaler[i];
+      const uint32_t p = prescaler[i];                        // Extend to 32 bits for calculations
+      DEBUG_ECHOLNPGM("prescaler[", i, "]=", p);
       uint16_t res_fast_temp, res_pc_temp;
       if (is_timer2) {
         #if ENABLED(USE_OCR2A_AS_TOP)                         // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP
           const uint16_t rft = (F_CPU) / (p * f_desired);
           res_fast_temp = rft - 1;
           res_pc_temp = rft / 2;
+          DEBUG_ECHOLNPGM("(Timer2) res_fast_temp=", res_fast_temp, " res_pc_temp=", res_pc_temp);
         #else
           res_fast_temp = res_pc_temp = maxtop;
+          DEBUG_ECHOLNPGM("(Timer2) res_fast_temp=", maxtop, " res_pc_temp=", maxtop);
         #endif
       }
       else {
         if (p == 32 || p == 128) continue;                    // Skip TIMER2 specific prescalers when not TIMER2
         const uint16_t rft = (F_CPU) / (p * f_desired);
+        DEBUG_ECHOLNPGM("(Not Timer 2) F_CPU=" STRINGIFY(F_CPU), " prescaler=", p, " f_desired=", f_desired);
         res_fast_temp = rft - 1;
         res_pc_temp = rft / 2;
       }
@@ -146,24 +159,28 @@ void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
       LIMIT(res_pc_temp, 1U, maxtop);
 
       // Calculate frequencies of test prescaler and resolution values
-      const uint32_t f_diff      = _MAX(f, f_desired) - _MIN(f, f_desired),
-                     f_fast_temp = (F_CPU) / (p * (1 + res_fast_temp)),
+      const uint16_t f_fast_temp = (F_CPU) / (p * (1 + res_fast_temp)),
+                     f_pc_temp   = (F_CPU) / ((p * res_pc_temp) << 1),
+                     f_diff      = _MAX(f, f_desired) - _MIN(f, f_desired),
                      f_fast_diff = _MAX(f_fast_temp, f_desired) - _MIN(f_fast_temp, f_desired),
-                     f_pc_temp   = (F_CPU) / (2 * p * res_pc_temp),
                      f_pc_diff   = _MAX(f_pc_temp, f_desired) - _MIN(f_pc_temp, f_desired);
 
+      DEBUG_ECHOLNPGM("f_fast_temp=", f_fast_temp, " f_pc_temp=", f_pc_temp, " f_diff=", f_diff, " f_fast_diff=", f_fast_diff, " f_pc_diff=", f_pc_diff);
+
       if (f_fast_diff < f_diff && f_fast_diff <= f_pc_diff) { // FAST values are closest to desired f
         // Set the Wave Generation Mode to FAST PWM
         wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_FAST_PWM_OCR2A, WGM2_FAST_PWM)) : uint8_t(WGM_FAST_PWM_ICRn);
         // Remember this combination
         f = f_fast_temp; res = res_fast_temp; j = i + 1;
+        DEBUG_ECHOLNPGM("(FAST) updated f=", f);
       }
       else if (f_pc_diff < f_diff) {                          // PHASE CORRECT values are closes to desired f
         // Set the Wave Generation Mode to PWM PHASE CORRECT
         wgm = is_timer2 ? uint8_t(TERN(USE_OCR2A_AS_TOP, WGM2_PWM_PC_OCR2A, WGM2_PWM_PC)) : uint8_t(WGM_PWM_PC_ICRn);
         f = f_pc_temp; res = res_pc_temp; j = i + 1;
+        DEBUG_ECHOLNPGM("(PHASE) updated f=", f);
       }
-    }
+    } // prescaler loop
   }
 
   _SET_WGMnQ(timer, wgm);

Marlin/src/HAL/AVR/fastio.h

@@ -293,11 +293,11 @@ enum ClockSource2 : uint8_t {
 
 #if HAS_MOTOR_CURRENT_PWM
   #if PIN_EXISTS(MOTOR_CURRENT_PWM_XY)
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1 || P == MOTOR_CURRENT_PWM_Z || P == MOTOR_CURRENT_PWM_XY)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E_PIN || P == MOTOR_CURRENT_PWM_E0_PIN  || P == MOTOR_CURRENT_PWM_E1_PIN || P == MOTOR_CURRENT_PWM_Z_PIN || P == MOTOR_CURRENT_PWM_XY_PIN)
   #elif PIN_EXISTS(MOTOR_CURRENT_PWM_Z)
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1 || P == MOTOR_CURRENT_PWM_Z)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E_PIN || P == MOTOR_CURRENT_PWM_E0_PIN  || P == MOTOR_CURRENT_PWM_E1_PIN || P == MOTOR_CURRENT_PWM_Z_PIN)
   #else
-    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E || P == MOTOR_CURRENT_PWM_E0  || P == MOTOR_CURRENT_PWM_E1)
+    #define PWM_CHK_MOTOR_CURRENT(P) (P == MOTOR_CURRENT_PWM_E_PIN || P == MOTOR_CURRENT_PWM_E0_PIN  || P == MOTOR_CURRENT_PWM_E1_PIN)
   #endif
 #else
   #define PWM_CHK_MOTOR_CURRENT(P) false

Marlin/src/HAL/AVR/inc/SanityCheck.h

@@ -40,13 +40,15 @@
 #if SERIAL_IN_USE(0)
   // D0-D1. No known conflicts.
 #endif
-#if NOT_TARGET(__AVR_ATmega644P__, __AVR_ATmega1284P__)
-  #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19))
-    #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
-  #endif
-#else
-  #if SERIAL_IN_USE(1) && (CHECK_SERIAL_PIN(10) || CHECK_SERIAL_PIN(11))
-    #error "Serial Port 1 pin D10 and/or D11 conflicts with another pin on the board."
+#if SERIAL_IN_USE(1)
+  #if NOT_TARGET(__AVR_ATmega644P__, __AVR_ATmega1284P__)
+    #if CHECK_SERIAL_PIN(18) || CHECK_SERIAL_PIN(19)
+      #error "Serial Port 1 pin D18 and/or D19 conflicts with another pin on the board."
+    #endif
+  #else
+    #if CHECK_SERIAL_PIN(10) || CHECK_SERIAL_PIN(11)
+      #error "Serial Port 1 pin D10 and/or D11 conflicts with another pin on the board."
+    #endif
   #endif
 #endif
 #if SERIAL_IN_USE(2) && (CHECK_SERIAL_PIN(16) || CHECK_SERIAL_PIN(17))

Marlin/src/HAL/AVR/math.h

@@ -27,13 +27,14 @@
 
 // intRes = longIn1 * longIn2 >> 24
 // uses:
-// A[tmp] to store 0
-// B[tmp] to store bits 16-23 of the 48bit result. The top bit is used to round the two byte result.
-// note that the lower two bytes and the upper byte of the 48bit result are not calculated.
-// this can cause the result to be out by one as the lower bytes may cause carries into the upper ones.
-// B A are bits 24-39 and are the returned value
-// C B A is longIn1
-// D C B A is longIn2
+// r1, r0 for the result of mul.
+// [tmp1] to store 0.
+// [tmp2] to store bits 16-23 of the 56 bit result. The top bit of [tmp2] is used for rounding.
+// Note that the lower two bytes and the upper two bytes of the 56 bit result are not calculated.
+// This can cause the result to be out by one as the lower bytes may cause carries into the upper ones.
+// [intRes] (A B) is bits 24-39 and is the returned value.
+// [longIn1] (C B A) is a 24 bit parameter.
+// [longIn2] (D C B A) is a 32 bit parameter.
 //
 FORCE_INLINE static uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2) {
   uint8_t tmp1;
@@ -66,11 +67,9 @@ FORCE_INLINE static uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2
     A("add %[tmp2], r1")
     A("adc %A[intRes], %[tmp1]")
     A("adc %B[intRes], %[tmp1]")
-    A("lsr %[tmp2]")
-    A("adc %A[intRes], %[tmp1]")
-    A("adc %B[intRes], %[tmp1]")
     A("mul %D[longIn2], %A[longIn1]")
-    A("add %A[intRes], r0")
+    A("lsl %[tmp2]")
+    A("adc %A[intRes], r0")
     A("adc %B[intRes], r1")
     A("mul %D[longIn2], %B[longIn1]")
     A("add %B[intRes], r0")
@@ -85,11 +84,16 @@ FORCE_INLINE static uint16_t MultiU24X32toH16(uint32_t longIn1, uint32_t longIn2
   return intRes;
 }
 
-// intRes = intIn1 * intIn2 >> 16
+// intRes = intIn1 * intIn2 >> 8
 // uses:
-// r26 to store 0
-// r27 to store the byte 1 of the 24 bit result
-FORCE_INLINE static uint16_t MultiU16X8toH16(uint8_t charIn1, uint16_t intIn2) {
+// r1, r0 for the result of mul. After the second mul, r0 holds bits 0-7 of the 24 bit result and
+// the top bit of r0 is used for rounding.
+// [tmp] to store 0.
+// [intRes] (A B) is bits 8-15 and is the returned value.
+// [charIn1] is an 8 bit parameter.
+// [intIn2] (B A) is a 16 bit parameter.
+//
+FORCE_INLINE static uint16_t MultiU8X16toH16(uint8_t charIn1, uint16_t intIn2) {
   uint8_t tmp;
   uint16_t intRes;
   __asm__ __volatile__ (
@@ -97,10 +101,8 @@ FORCE_INLINE static uint16_t MultiU16X8toH16(uint8_t charIn1, uint16_t intIn2) {
     A("mul %[charIn1], %B[intIn2]")
     A("movw %A[intRes], r0")
     A("mul %[charIn1], %A[intIn2]")
-    A("add %A[intRes], r1")
-    A("adc %B[intRes], %[tmp]")
-    A("lsr r0")
-    A("adc %A[intRes], %[tmp]")
+    A("lsl r0")
+    A("adc %A[intRes], r1")
     A("adc %B[intRes], %[tmp]")
     A("clr r1")
       : [intRes] "=&r" (intRes),

Marlin/src/HAL/DUE/MarlinSerial.h

@@ -30,6 +30,7 @@
 #include <WString.h>
 
 #include "../../inc/MarlinConfigPre.h"
+#include "../../core/types.h"
 #include "../../core/serial_hook.h"
 
 // Define constants and variables for buffering incoming serial data.  We're
@@ -52,10 +53,6 @@
 //  #error "TX_BUFFER_SIZE must be 0, a power of 2 greater than 1, and no greater than 256."
 //#endif
 
-// Templated type selector
-template<bool b, typename T, typename F> struct TypeSelector { typedef T type;} ;
-template<typename T, typename F> struct TypeSelector<false, T, F> { typedef F type; };
-
 // Templated structure wrapper
 template<typename S, unsigned int addr> struct StructWrapper {
   constexpr StructWrapper(int) {}
@@ -76,7 +73,7 @@ protected:
   static constexpr int HWUART_IRQ_ID = IRQ_IDS[Cfg::PORT];
 
   // Base size of type on buffer size
-  typedef typename TypeSelector<(Cfg::RX_SIZE>256), uint16_t, uint8_t>::type ring_buffer_pos_t;
+  typedef uvalue_t(Cfg::RX_SIZE - 1) ring_buffer_pos_t;
 
   struct ring_buffer_r {
     volatile ring_buffer_pos_t head, tail;

Marlin/src/HAL/ESP32/HAL.cpp

@@ -342,16 +342,16 @@ void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v
       }
       else
         pindata.pwm_duty_ticks = duty; // PWM duty count = # of 4µs ticks per full PWM cycle
+
+      return;
     }
-    else
   #endif
-    {
-      const int8_t cid = get_pwm_channel(pin, PWM_FREQUENCY, PWM_RESOLUTION);
-      if (cid >= 0) {
-        const uint32_t duty = map(invert ? v_size - v : v, 0, v_size, 0, _BV(PWM_RESOLUTION)-1);
-        ledcWrite(cid, duty);
-      }
-    }
+
+  const int8_t cid = get_pwm_channel(pin, PWM_FREQUENCY, PWM_RESOLUTION);
+  if (cid >= 0) {
+    const uint32_t duty = map(invert ? v_size - v : v, 0, v_size, 0, _BV(PWM_RESOLUTION)-1);
+    ledcWrite(cid, duty);
+  }
 }
 
 int8_t MarlinHAL::set_pwm_frequency(const pin_t pin, const uint32_t f_desired) {
@@ -360,17 +360,15 @@ int8_t MarlinHAL::set_pwm_frequency(const pin_t pin, const uint32_t f_desired) {
       pwm_pin_data[pin & 0x7F].pwm_cycle_ticks = 1000000UL / f_desired / 4; // # of 4µs ticks per full PWM cycle
       return 0;
     }
-    else
   #endif
-    {
-      const int8_t cid = channel_for_pin(pin);
-      if (cid >= 0) {
-        if (f_desired == ledcReadFreq(cid)) return cid; // no freq change
-        ledcDetachPin(chan_pin[cid]);
-        chan_pin[cid] = 0;              // remove old freq channel
-      }
-      return get_pwm_channel(pin, f_desired, PWM_RESOLUTION); // try for new one
-    }
+
+  const int8_t cid = channel_for_pin(pin);
+  if (cid >= 0) {
+    if (f_desired == ledcReadFreq(cid)) return cid; // no freq change
+    ledcDetachPin(chan_pin[cid]);
+    chan_pin[cid] = 0;              // remove old freq channel
+  }
+  return get_pwm_channel(pin, f_desired, PWM_RESOLUTION); // try for new one
 }
 
 // use hardware PWM if avail, if not then ISR

Marlin/src/HAL/ESP32/i2s.cpp

@@ -149,30 +149,28 @@ void stepperTask(void *parameter) {
     dma.rw_pos = 0;
 
     while (dma.rw_pos < DMA_SAMPLE_COUNT) {
-      // Fill with the port data post pulse_phase until the next step
-      if (nextMainISR && TERN1(LIN_ADVANCE, nextAdvanceISR))
-        i2s_push_sample();
-
-      // i2s_push_sample() is also called from Stepper::pulse_phase_isr() and Stepper::advance_isr()
-      // in a rare case where both are called, we need to double decrement the counters
-      const uint8_t push_count = 1 + (!nextMainISR && TERN0(LIN_ADVANCE, !nextAdvanceISR));
-
-      #if ENABLED(LIN_ADVANCE)
-        if (!nextAdvanceISR) {
-          Stepper::advance_isr();
-          nextAdvanceISR = Stepper::la_interval;
-        }
-        else if (nextAdvanceISR == Stepper::LA_ADV_NEVER)
-          nextAdvanceISR = Stepper::la_interval;
-      #endif
-
       if (!nextMainISR) {
         Stepper::pulse_phase_isr();
         nextMainISR = Stepper::block_phase_isr();
       }
+      #if ENABLED(LIN_ADVANCE)
+        else if (!nextAdvanceISR) {
+          Stepper::advance_isr();
+          nextAdvanceISR = Stepper::la_interval;
+        }
+      #endif
+      else
+        i2s_push_sample();
 
-      nextMainISR -= push_count;
-      TERN_(LIN_ADVANCE, nextAdvanceISR -= push_count);
+      nextMainISR--;
+
+      #if ENABLED(LIN_ADVANCE)
+        if (nextAdvanceISR == Stepper::LA_ADV_NEVER)
+          nextAdvanceISR = Stepper::la_interval;
+
+        if (nextAdvanceISR && nextAdvanceISR != Stepper::LA_ADV_NEVER)
+          nextAdvanceISR--;
+      #endif
     }
   }
 }

Marlin/src/HAL/LPC1768/HAL_SPI.cpp

@@ -318,8 +318,16 @@ void SPIClass::dmaSend(void *buf, uint16_t length, bool minc) {
   // Enable DMA
   GPDMA_ChannelCmd(0, ENABLE);
 
+  /*
+   * Observed behaviour on normal data transfer completion (SKR 1.3 board / LPC1768 MCU)
+   *   GPDMA_STAT_INTTC flag is SET
+   *   GPDMA_STAT_INTERR flag is NOT SET
+   *   GPDMA_STAT_RAWINTTC flag is NOT SET
+   *   GPDMA_STAT_RAWINTERR flag is SET
+   */
+
   // Wait for data transfer
-  while (!GPDMA_IntGetStatus(GPDMA_STAT_RAWINTTC, 0) && !GPDMA_IntGetStatus(GPDMA_STAT_RAWINTERR, 0)) { }
+  while (!GPDMA_IntGetStatus(GPDMA_STAT_INTTC, 0) && !GPDMA_IntGetStatus(GPDMA_STAT_INTERR, 0)) {}
 
   // Clear err and int
   GPDMA_ClearIntPending (GPDMA_STATCLR_INTTC, 0);
@@ -333,6 +341,43 @@ void SPIClass::dmaSend(void *buf, uint16_t length, bool minc) {
   SSP_DMACmd(_currentSetting->spi_d, SSP_DMA_TX, DISABLE);
 }
 
+void SPIClass::dmaSendAsync(void *buf, uint16_t length, bool minc) {
+  //TODO: LPC dma can only write 0xFFF bytes at once.
+  GPDMA_Channel_CFG_Type GPDMACfg;
+
+  /* Configure GPDMA channel 0 -------------------------------------------------------------*/
+  /* DMA Channel 0 */
+  GPDMACfg.ChannelNum = 0;
+  // Source memory
+  GPDMACfg.SrcMemAddr = (uint32_t)buf;
+  // Destination memory - Not used
+  GPDMACfg.DstMemAddr = 0;
+  // Transfer size
+  GPDMACfg.TransferSize = length;
+  // Transfer width
+  GPDMACfg.TransferWidth = (_currentSetting->dataSize == DATA_SIZE_16BIT) ? GPDMA_WIDTH_HALFWORD : GPDMA_WIDTH_BYTE;
+  // Transfer type
+  GPDMACfg.TransferType = GPDMA_TRANSFERTYPE_M2P;
+  // Source connection - unused
+  GPDMACfg.SrcConn = 0;
+  // Destination connection
+  GPDMACfg.DstConn = (_currentSetting->spi_d == LPC_SSP0) ? GPDMA_CONN_SSP0_Tx : GPDMA_CONN_SSP1_Tx;
+
+  GPDMACfg.DMALLI = 0;
+
+  // Enable dma on SPI
+  SSP_DMACmd(_currentSetting->spi_d, SSP_DMA_TX, ENABLE);
+
+  // Only increase memory if minc is true
+  GPDMACfg.MemoryIncrease = (minc ? GPDMA_DMACCxControl_SI : 0);
+
+  // Setup channel with given parameter
+  GPDMA_Setup(&GPDMACfg);
+
+  // Enable DMA
+  GPDMA_ChannelCmd(0, ENABLE);
+}
+
 uint16_t SPIClass::read() {
   return SSP_ReceiveData(_currentSetting->spi_d);
 }

Marlin/src/HAL/LPC1768/include/SPI.h

@@ -155,6 +155,7 @@ public:
   void read(uint8_t *buf, uint32_t len);
 
   void dmaSend(void *buf, uint16_t length, bool minc);
+  void dmaSendAsync(void *buf, uint16_t length, bool minc);
 
   /**
    * @brief Sets the number of the SPI peripheral to be used by

Marlin/src/HAL/LPC1768/tft/tft_spi.cpp

@@ -26,7 +26,7 @@
 
 #include "tft_spi.h"
 
-SPIClass TFT_SPI::SPIx(1);
+SPIClass TFT_SPI::SPIx(TFT_SPI_DEVICE);
 
 void TFT_SPI::Init() {
   #if PIN_EXISTS(TFT_RESET)
@@ -38,40 +38,10 @@ void TFT_SPI::Init() {
     OUT_WRITE(TFT_BACKLIGHT_PIN, HIGH);
   #endif
 
-  SET_OUTPUT(TFT_DC_PIN);
-  SET_OUTPUT(TFT_CS_PIN);
-  WRITE(TFT_DC_PIN, HIGH);
-  WRITE(TFT_CS_PIN, HIGH);
+  OUT_WRITE(TFT_DC_PIN, HIGH);
+  OUT_WRITE(TFT_CS_PIN, HIGH);
 
-  /**
-   * STM32F1 APB2 = 72MHz, APB1 = 36MHz, max SPI speed of this MCU if 18Mhz
-   * STM32F1 has 3 SPI ports, SPI1 in APB2, SPI2/SPI3 in APB1
-   * so the minimum prescale of SPI1 is DIV4, SPI2/SPI3 is DIV2
-   */
-  #if 0
-    #if SPI_DEVICE == 1
-     #define SPI_CLOCK_MAX SPI_CLOCK_DIV4
-    #else
-     #define SPI_CLOCK_MAX SPI_CLOCK_DIV2
-    #endif
-    uint8_t  clock;
-    uint8_t spiRate = SPI_FULL_SPEED;
-    switch (spiRate) {
-     case SPI_FULL_SPEED:    clock = SPI_CLOCK_MAX ;  break;
-     case SPI_HALF_SPEED:    clock = SPI_CLOCK_DIV4 ; break;
-     case SPI_QUARTER_SPEED: clock = SPI_CLOCK_DIV8 ; break;
-     case SPI_EIGHTH_SPEED:  clock = SPI_CLOCK_DIV16; break;
-     case SPI_SPEED_5:       clock = SPI_CLOCK_DIV32; break;
-     case SPI_SPEED_6:       clock = SPI_CLOCK_DIV64; break;
-     default:                clock = SPI_CLOCK_DIV2;  // Default from the SPI library
-    }
-  #endif
-
-  #if TFT_MISO_PIN == BOARD_SPI1_MISO_PIN
-    SPIx.setModule(1);
-  #elif TFT_MISO_PIN == BOARD_SPI2_MISO_PIN
-    SPIx.setModule(2);
-  #endif
+  SPIx.setModule(TFT_SPI_DEVICE);
   SPIx.setClock(SPI_CLOCK_MAX_TFT);
   SPIx.setBitOrder(MSBFIRST);
   SPIx.setDataMode(SPI_MODE0);
@@ -114,17 +84,62 @@ uint32_t TFT_SPI::ReadID(uint16_t Reg) {
   return data >> 7;
 }
 
-bool TFT_SPI::isBusy() { return false; }
+bool TFT_SPI::isBusy() {
+  #define __IS_DMA_CONFIGURED(__HANDLE__)   ((__HANDLE__)->DMACCSrcAddr != 0)
 
-void TFT_SPI::Abort() { DataTransferEnd(); }
+  // DMA Channel 0 is hardcoded in dmaSendAsync() and dmaSend()
+  if (!__IS_DMA_CONFIGURED(LPC_GPDMACH0)) return false;
 
-void TFT_SPI::Transmit(uint16_t Data) { SPIx.transfer(Data); }
+  if (GPDMA_IntGetStatus(GPDMA_STAT_INTERR, 0)) {
+    // You should not be here - DMA transfer error flag is set
+    // Abort DMA transfer and release SPI
+  }
+  else {
+    // Check if DMA transfer completed flag is set
+    if (!GPDMA_IntGetStatus(GPDMA_STAT_INTTC, 0)) return true;
+    // Check if SPI TX butter is empty and SPI is idle
+    if ((SSP_GetStatus(LPC_SSPx, SSP_STAT_TXFIFO_EMPTY) == RESET) || (SSP_GetStatus(LPC_SSPx, SSP_STAT_BUSY) == SET)) return true;
+  }
+
+  Abort();
+  return false;
+}
+
+void TFT_SPI::Abort() {
+  // DMA Channel 0 is hardcoded in dmaSendAsync() and dmaSend()
+
+  // Disable DMA
+  GPDMA_ChannelCmd(0, DISABLE);
+
+  // Clear ERR and TC
+  GPDMA_ClearIntPending(GPDMA_STATCLR_INTTC, 0);
+  GPDMA_ClearIntPending(GPDMA_STATCLR_INTERR, 0);
+
+  // Disable DMA on SPI
+  SSP_DMACmd(LPC_SSPx, SSP_DMA_TX, DISABLE);
+
+  // Deconfigure DMA Channel 0
+  LPC_GPDMACH0->DMACCControl  = 0U;
+  LPC_GPDMACH0->DMACCConfig   = 0U;
+  LPC_GPDMACH0->DMACCSrcAddr  = 0U;
+  LPC_GPDMACH0->DMACCDestAddr = 0U;
 
-void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
-  DataTransferBegin(DATASIZE_16BIT);
-  WRITE(TFT_DC_PIN, HIGH);
-  SPIx.dmaSend(Data, Count, MemoryIncrease);
   DataTransferEnd();
 }
 
+void TFT_SPI::Transmit(uint16_t Data) { SPIx.transfer(Data); }
+
+void TFT_SPI::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+  DataTransferBegin(DATASIZE_16BIT);
+  SPIx.dmaSend(Data, Count, MemoryIncrease);
+  Abort();
+}
+
+void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+  DataTransferBegin(DATASIZE_16BIT);
+  SPIx.dmaSendAsync(Data, Count, MemoryIncrease);
+
+  TERN_(TFT_SHARED_SPI, while (isBusy()));
+}
+
 #endif // HAS_SPI_TFT

Marlin/src/HAL/LPC1768/tft/tft_spi.h

@@ -27,6 +27,18 @@
 #include <lpc17xx_ssp.h>
 // #include <lpc17xx_gpdma.h>
 
+#define IS_SPI(N) (BOARD_NR_SPI >= N && (TFT_SCK_PIN == BOARD_SPI##N##_SCK_PIN) && (TFT_MOSI_PIN == BOARD_SPI##N##_MOSI_PIN) && (TFT_MISO_PIN == BOARD_SPI##N##_MISO_PIN))
+#if IS_SPI(1)
+  #define TFT_SPI_DEVICE  1
+  #define LPC_SSPx  LPC_SSP0
+#elif IS_SPI(2)
+  #define TFT_SPI_DEVICE  2
+  #define LPC_SSPx  LPC_SSP1
+#else
+  #error "Invalid TFT SPI configuration."
+#endif
+#undef IS_SPI
+
 #ifndef LCD_READ_ID
   #define LCD_READ_ID  0x04   // Read display identification information (0xD3 on ILI9341)
 #endif
@@ -34,17 +46,19 @@
   #define LCD_READ_ID4 0xD3   // Read display identification information (0xD3 on ILI9341)
 #endif
 
-#define DATASIZE_8BIT    SSP_DATABIT_8
-#define DATASIZE_16BIT   SSP_DATABIT_16
-#define TFT_IO_DRIVER TFT_SPI
+#define DATASIZE_8BIT     SSP_DATABIT_8
+#define DATASIZE_16BIT    SSP_DATABIT_16
+#define TFT_IO_DRIVER     TFT_SPI
+#define DMA_MAX_SIZE      0xFFF
 
-#define DMA_MINC_ENABLE 1
-#define DMA_MINC_DISABLE 0
+#define DMA_MINC_ENABLE   1
+#define DMA_MINC_DISABLE  0
 
 class TFT_SPI {
 private:
   static uint32_t ReadID(uint16_t Reg);
   static void Transmit(uint16_t Data);
+  static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
   static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
 
 public:
@@ -56,22 +70,20 @@ public:
   static void Abort();
 
   static void DataTransferBegin(uint16_t DataWidth = DATASIZE_16BIT);
-  static void DataTransferEnd() { OUT_WRITE(TFT_CS_PIN, HIGH); SPIx.end(); };
+  static void DataTransferEnd() { WRITE(TFT_CS_PIN, HIGH); SSP_Cmd(LPC_SSPx, DISABLE); };
   static void DataTransferAbort();
 
   static void WriteData(uint16_t Data) { Transmit(Data); }
-  static void WriteReg(uint16_t Reg) { OUT_WRITE(TFT_A0_PIN, LOW); Transmit(Reg); OUT_WRITE(TFT_A0_PIN, HIGH); }
+  static void WriteReg(uint16_t Reg) { WRITE(TFT_DC_PIN, LOW); Transmit(Reg); WRITE(TFT_DC_PIN, HIGH); }
 
-  static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
-  // static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
+  static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
+  static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
+
+  static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_MINC_ENABLE, Data, Count); }
   static void WriteMultiple(uint16_t Color, uint32_t Count) {
-    static uint16_t Data; Data = Color;
-    //LPC dma can only write 0xFFF bytes at once.
-    #define MAX_DMA_SIZE (0xFFF - 1)
     while (Count > 0) {
-      TransmitDMA(DMA_MINC_DISABLE, &Data, Count > MAX_DMA_SIZE ? MAX_DMA_SIZE : Count);
-      Count = Count > MAX_DMA_SIZE ? Count - MAX_DMA_SIZE : 0;
+      Transmit(DMA_MINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+      Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
     }
-    #undef MAX_DMA_SIZE
   }
 };

Marlin/src/HAL/LPC1768/tft/xpt2046.cpp

@@ -44,9 +44,11 @@ uint16_t delta(uint16_t a, uint16_t b) { return a > b ? a - b : b - a; }
 #endif
 
 void XPT2046::Init() {
-  SET_INPUT(TOUCH_MISO_PIN);
-  SET_OUTPUT(TOUCH_MOSI_PIN);
-  SET_OUTPUT(TOUCH_SCK_PIN);
+  #if DISABLED(TOUCH_BUTTONS_HW_SPI)
+    SET_INPUT(TOUCH_MISO_PIN);
+    SET_OUTPUT(TOUCH_MOSI_PIN);
+    SET_OUTPUT(TOUCH_SCK_PIN);
+  #endif
   OUT_WRITE(TOUCH_CS_PIN, HIGH);
 
   #if PIN_EXISTS(TOUCH_INT)

Marlin/src/HAL/NATIVE_SIM/HAL.h

@@ -208,8 +208,8 @@ public:
   MarlinHAL() {}
 
   // Watchdog
-  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
-  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_init();
+  static void watchdog_refresh();
 
   static void init() {}        // Called early in setup()
   static void init_board() {}  // Called less early in setup()

Marlin/src/HAL/NATIVE_SIM/tft/tft_spi.h

@@ -31,10 +31,11 @@
 #endif
 
 #define DATASIZE_8BIT    8
-#define DATASIZE_16BIT   16
-#define TFT_IO_DRIVER TFT_SPI
+#define DATASIZE_16BIT  16
+#define TFT_IO_DRIVER   TFT_SPI
+#define DMA_MAX_SIZE    0xFFFF
 
-#define DMA_MINC_ENABLE 1
+#define DMA_MINC_ENABLE  1
 #define DMA_MINC_DISABLE 0
 
 class TFT_SPI {
@@ -58,7 +59,9 @@ public:
   static void WriteData(uint16_t Data);
   static void WriteReg(uint16_t Reg);
 
+  static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { WriteSequence(Data, Count); }
+  static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { WriteMultiple(Color, Count); }
+
   static void WriteSequence(uint16_t *Data, uint16_t Count);
-  // static void WriteMultiple(uint16_t Color, uint16_t Count);
   static void WriteMultiple(uint16_t Color, uint32_t Count);
 };

Marlin/src/HAL/NATIVE_SIM/u8g/u8g_com_st7920_sw_spi.cpp

@@ -168,4 +168,4 @@ uint8_t u8g_com_ST7920_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void
 #endif
 
 #endif // IS_U8GLIB_ST7920
-#endif // TARGET_LPC1768
+#endif // __PLAT_NATIVE_SIM__

Marlin/src/HAL/SAMD21/HAL.cpp

@@ -0,0 +1,212 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#ifdef __SAMD21__
+
+#include "../../inc/MarlinConfig.h"
+
+#include <wiring_private.h>
+
+#if USING_HW_SERIALUSB
+  DefaultSerial1 MSerialUSB(false, SerialUSB);
+#endif
+#if USING_HW_SERIAL0
+  DefaultSerial2 MSerial1(false, Serial1);
+#endif
+#if USING_HW_SERIAL1
+  DefaultSerial3 MSerial2(false, Serial2);
+#endif
+
+
+
+#define WDT_CONFIG_PER_7_Val 0x9u
+#define WDT_CONFIG_PER_Pos 0
+#define WDT_CONFIG_PER_7 (WDT_CONFIG_PER_7_Val << WDT_CONFIG_PER_Pos)
+
+#if ENABLED(USE_WATCHDOG)
+
+  #define WDT_TIMEOUT_REG TERN(WATCHDOG_DURATION_8S, WDT_CONFIG_PER_CYC8192, WDT_CONFIG_PER_CYC4096) // 4 or 8 second timeout
+
+  void MarlinHAL::watchdog_init() {
+       // Set up the generic clock (GCLK2) used to clock the watchdog timer at 1.024kHz
+    GCLK->GENDIV.reg = GCLK_GENDIV_DIV(4) |            // Divide the 32.768kHz clock source by divisor 32, where 2^(4 + 1): 32.768kHz/32=1.024kHz
+                      GCLK_GENDIV_ID(2);              // Select Generic Clock (GCLK) 2
+    while (GCLK->STATUS.bit.SYNCBUSY);                // Wait for synchronization
+
+    REG_GCLK_GENCTRL =  GCLK_GENCTRL_DIVSEL |         // Set to divide by 2^(GCLK_GENDIV_DIV(4) + 1)
+                        GCLK_GENCTRL_IDC |            // Set the duty cycle to 50/50 HIGH/LOW
+                        GCLK_GENCTRL_GENEN |          // Enable GCLK2
+                        GCLK_GENCTRL_SRC_OSCULP32K |  // Set the clock source to the ultra low power oscillator (OSCULP32K)
+                        GCLK_GENCTRL_ID(2);           // Select GCLK2
+    while (GCLK->STATUS.bit.SYNCBUSY);                // Wait for synchronization
+
+    // Feed GCLK2 to WDT (Watchdog Timer)
+    REG_GCLK_CLKCTRL =  GCLK_CLKCTRL_CLKEN |          // Enable GCLK2 to the WDT
+                        GCLK_CLKCTRL_GEN_GCLK2 |      // Select GCLK2
+                        GCLK_CLKCTRL_ID_WDT;          // Feed the GCLK2 to the WDT
+    while (GCLK->STATUS.bit.SYNCBUSY);                // Wait for synchronization
+
+    WDT->CONFIG.bit.PER = WDT_CONFIG_PER_7;                // Set the WDT reset timeout to 4 seconds
+    while (WDT->STATUS.bit.SYNCBUSY);                 // Wait for synchronization
+    REG_WDT_CTRL = WDT_CTRL_ENABLE;                   // Enable the WDT in normal mode
+    while (WDT->STATUS.bit.SYNCBUSY);                 // Wait for synchronization
+  }
+
+  // Reset watchdog. MUST be called at least every 4 seconds after the
+  // first watchdog_init or SAMD will go into emergency procedures.
+  void MarlinHAL::watchdog_refresh() {
+    WDT->CLEAR.reg = WDT_CLEAR_CLEAR_KEY;
+    while (WDT->STATUS.bit.SYNCBUSY);
+  }
+
+#endif
+
+// ------------------------
+// Types
+// ------------------------
+
+// ------------------------
+// Private Variables
+// ------------------------
+
+// ------------------------
+// Private functions
+// ------------------------
+
+void MarlinHAL::dma_init() {}
+
+// ------------------------
+// Public functions
+// ------------------------
+
+// HAL initialization task
+void MarlinHAL::init() {
+  TERN_(DMA_IS_REQUIRED, dma_init());
+  #if ENABLED(SDSUPPORT)
+    #if HAS_SD_DETECT && SD_CONNECTION_IS(ONBOARD)
+      SET_INPUT_PULLUP(SD_DETECT_PIN);
+    #endif
+    OUT_WRITE(SDSS, HIGH);  // Try to set SDSS inactive before any other SPI users start up
+  #endif
+}
+
+#pragma push_macro("WDT")
+#undef WDT    // Required to be able to use '.bit.WDT'. Compiler wrongly replace struct field with WDT define
+uint8_t MarlinHAL::get_reset_source() {
+
+  return 0;
+}
+#pragma pop_macro("WDT")
+
+void MarlinHAL::reboot() { NVIC_SystemReset(); }
+
+extern "C" {
+  void * _sbrk(int incr);
+  extern unsigned int __bss_end__; // end of bss section
+}
+
+// Return free memory between end of heap (or end bss) and whatever is current
+int freeMemory() {
+  int free_memory, heap_end = (int)_sbrk(0);
+  return (int)&free_memory - (heap_end ?: (int)&__bss_end__);
+}
+
+// ------------------------
+// ADC
+// ------------------------
+
+uint16_t MarlinHAL::adc_result;
+
+void MarlinHAL::adc_init() {
+  /* thanks to https://www.eevblog.com/forum/microcontrollers/samd21g18-adc-with-resrdy-interrupts-only-reads-once-or-twice/ */
+
+  ADC->CTRLA.bit.ENABLE = false;
+  while(ADC->STATUS.bit.SYNCBUSY);
+
+  // load chip corrections
+  uint32_t bias = (*((uint32_t *) ADC_FUSES_BIASCAL_ADDR) & ADC_FUSES_BIASCAL_Msk) >> ADC_FUSES_BIASCAL_Pos;
+  uint32_t linearity = (*((uint32_t *) ADC_FUSES_LINEARITY_0_ADDR) & ADC_FUSES_LINEARITY_0_Msk) >> ADC_FUSES_LINEARITY_0_Pos;
+  linearity |= ((*((uint32_t *) ADC_FUSES_LINEARITY_1_ADDR) & ADC_FUSES_LINEARITY_1_Msk) >> ADC_FUSES_LINEARITY_1_Pos) << 5;
+
+  /* Wait for bus synchronization. */
+  while (ADC->STATUS.bit.SYNCBUSY) {};
+
+  ADC->CALIB.reg = ADC_CALIB_BIAS_CAL(bias) | ADC_CALIB_LINEARITY_CAL(linearity);
+
+  /* Wait for bus synchronization. */
+  while (ADC->STATUS.bit.SYNCBUSY) {};
+
+  ADC->CTRLA.bit.SWRST = true;
+  while(ADC->STATUS.bit.SYNCBUSY);
+
+  ADC->REFCTRL.reg = ADC_REFCTRL_REFSEL_INTVCC1;
+  ADC->AVGCTRL.reg = ADC_AVGCTRL_SAMPLENUM_32| ADC_AVGCTRL_ADJRES(4);;
+
+
+  ADC->CTRLB.reg = ADC_CTRLB_PRESCALER_DIV128 |
+                 ADC_CTRLB_RESSEL_16BIT |
+                 ADC_CTRLB_FREERUN;
+  while(ADC->STATUS.bit.SYNCBUSY);
+
+  ADC->SAMPCTRL.bit.SAMPLEN = 0x00;
+  while(ADC->STATUS.bit.SYNCBUSY);
+
+  ADC->INPUTCTRL.reg =  ADC_INPUTCTRL_INPUTSCAN(HAL_ADC_AIN_LEN) // scan  (INPUTSCAN + NUM_EXTUDERS - 1) pins
+  | ADC_INPUTCTRL_GAIN_DIV2  |ADC_INPUTCTRL_MUXNEG_GND| HAL_ADC_AIN_START ;  /* set to first AIN */
+
+  while(ADC->STATUS.bit.SYNCBUSY);
+
+  ADC->INTENSET.reg |= ADC_INTENSET_RESRDY; // enable Result Ready ADC interrupts
+  while (ADC->STATUS.bit.SYNCBUSY);
+
+  NVIC_EnableIRQ(ADC_IRQn); // enable ADC interrupts
+
+  NVIC_SetPriority(ADC_IRQn, 3);
+
+  ADC->CTRLA.bit.ENABLE = true;
+}
+
+volatile uint32_t adc_results[HAL_ADC_AIN_NUM_SENSORS];
+
+void ADC_Handler() {
+  while(ADC->STATUS.bit.SYNCBUSY == 1);
+  int pos = ADC->INPUTCTRL.bit.INPUTOFFSET;
+
+  adc_results[pos] = ADC->RESULT.reg; /* Read the value. */
+  ADC->INTFLAG.reg = ADC_INTENSET_RESRDY; /* Clear the data ready flag. */
+}
+
+void MarlinHAL::adc_start(const pin_t pin) {
+  /* due to the way INPUTOFFSET works, the last sensor is the first position in the array
+    and we want the ADC_handler interrupt to be as simple possible, so we do the calculation here.
+  */
+  unsigned int pos = PIN_TO_INPUTCTRL(pin) - HAL_ADC_AIN_START + 1;
+  if (pos == HAL_ADC_AIN_NUM_SENSORS) pos = 0;
+  adc_result = adc_results[pos]; // 16-bit resolution
+  //adc_result = 0xFFFF;
+}
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/HAL.h

@@ -0,0 +1,223 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+#define CPU_32_BIT
+
+#include "../shared/Marduino.h"
+#include "../shared/math_32bit.h"
+#include "../shared/HAL_SPI.h"
+#include "fastio.h"
+
+// ------------------------
+// Serial ports
+// ------------------------
+#include "../../core/serial_hook.h"
+typedef ForwardSerial1Class< decltype(SerialUSB) > DefaultSerial1;
+extern DefaultSerial1 MSerialUSB;
+
+// Serial ports
+typedef ForwardSerial1Class< decltype(Serial1) > DefaultSerial2;
+typedef ForwardSerial1Class< decltype(Serial2) > DefaultSerial3;
+
+extern DefaultSerial2 MSerial0;
+extern DefaultSerial3 MSerial1;
+
+
+#define __MSERIAL(X) MSerial##X
+#define _MSERIAL(X) __MSERIAL(X)
+#define MSERIAL(X) _MSERIAL(INCREMENT(X))
+
+#if WITHIN(SERIAL_PORT, 0, 1)
+  #define MYSERIAL1 MSERIAL(SERIAL_PORT)
+#elif SERIAL_PORT == -1
+  #define MYSERIAL1 MSerialUSB
+#else
+  #error "SERIAL_PORT must be -1 (Native USB only)."
+#endif
+
+#ifdef SERIAL_PORT_2
+  #if WITHIN(SERIAL_PORT_2, 0, 1)
+    #define MYSERIAL2 MSERIAL(SERIAL_PORT)
+  #elif SERIAL_PORT_2 == -1
+    #define MYSERIAL2 MSerialUSB
+  #else
+    #error "SERIAL_PORT_2 must be -1 (Native USB only)."
+  #endif
+#endif
+
+#ifdef MMU2_SERIAL_PORT
+  #if WITHIN(MMU2_SERIAL_PORT, 0, 1)
+    #define MMU2_SERIAL MSERIAL(SERIAL_PORT)
+  #elif MMU2_SERIAL_PORT == -1
+    #define MMU2_SERIAL MSerialUSB
+  #else
+    #error "MMU2_SERIAL_PORT must be -1 (Native USB only)."
+  #endif
+#endif
+
+#ifdef LCD_SERIAL_PORT
+  #if WITHIN(LCD_SERIAL_PORT, 0, 1)
+    #define LCD_SERIAL MSERIAL(SERIAL_PORT)
+  #elif LCD_SERIAL_PORT == -1
+    #define LCD_SERIAL MSerialUSB
+  #else
+    #error "LCD_SERIAL_PORT must be -1 (Native USB only)."
+  #endif
+#endif
+
+typedef int8_t pin_t;
+
+#define SHARED_SERVOS HAS_SERVOS  // Use shared/servos.cpp
+
+class Servo;
+typedef Servo hal_servo_t;
+
+//
+// Interrupts
+//
+#define CRITICAL_SECTION_START()  const bool irqon = !__get_PRIMASK(); __disable_irq()
+#define CRITICAL_SECTION_END()    if (irqon) __enable_irq()
+
+#define cli() __disable_irq() // Disable interrupts
+#define sei() __enable_irq()  // Enable interrupts
+
+//
+// ADC
+//
+
+#define HAL_ADC_FILTERED     1     // Disable Marlin's oversampling. The HAL filters ADC values.
+#define HAL_ADC_VREF         3.3
+#define HAL_ADC_RESOLUTION   12
+#define HAL_ADC_AIN_START ADC_INPUTCTRL_MUXPOS_PIN3
+#define HAL_ADC_AIN_NUM_SENSORS 3
+#define HAL_ADC_AIN_LEN HAL_ADC_AIN_NUM_SENSORS-1
+
+//
+// Pin Mapping for M42, M43, M226
+//
+#define GET_PIN_MAP_PIN(index) index
+#define GET_PIN_MAP_INDEX(pin) pin
+#define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)
+
+//
+// Tone
+//
+void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration=0);
+void noTone(const pin_t _pin);
+
+// ------------------------
+// Class Utilities
+// ------------------------
+
+#pragma GCC diagnostic push
+#if GCC_VERSION <= 50000
+  #pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s);
+
+extern "C" int freeMemory();
+
+#ifdef __cplusplus
+  }
+#endif
+
+#pragma GCC diagnostic pop
+
+// ------------------------
+// MarlinHAL Class
+// ------------------------
+
+class MarlinHAL {
+public:
+
+  // Earliest possible init, before setup()
+  MarlinHAL() {}
+
+  // Watchdog
+  static void watchdog_init()    IF_DISABLED(USE_WATCHDOG, {});
+  static void watchdog_refresh() IF_DISABLED(USE_WATCHDOG, {});
+
+  static void init();          // Called early in setup()
+  static void init_board() {}  // Called less early in setup()
+  static void reboot();        // Restart the firmware from 0x0
+
+  // Interrupts
+  static bool isr_state() { return !__get_PRIMASK(); }
+  static void isr_on()  { sei(); }
+  static void isr_off() { cli(); }
+
+  static void delay_ms(const int ms) { delay(ms); }
+
+  // Tasks, called from idle()
+  static void idletask() {}
+
+  // Reset
+  static uint8_t get_reset_source();
+  static void clear_reset_source() {}
+
+  // Free SRAM
+  static int freeMemory() { return ::freeMemory(); }
+
+  //
+  // ADC Methods
+  //
+
+  static uint16_t adc_result;
+
+  // Called by Temperature::init once at startup
+  static void adc_init();
+
+  // Called by Temperature::init for each sensor at startup
+  static void adc_enable(const uint8_t ch) {}
+
+  // Begin ADC sampling on the given pin. Called from Temperature::isr!
+  static void adc_start(const pin_t pin);
+
+  // Is the ADC ready for reading?
+  static bool adc_ready() { return true; }
+
+  // The current value of the ADC register
+  static uint16_t adc_value() { return adc_result; }
+
+  /**
+   * Set the PWM duty cycle for the pin to the given value.
+   * No option to invert the duty cycle [default = false]
+   * No option to change the scale of the provided value to enable finer PWM duty control [default = 255]
+   */
+  static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t=255, const bool=false) {
+    analogWrite(pin, v);
+  }
+
+private:
+  static void dma_init();
+};

Marlin/src/HAL/SAMD21/HAL_SPI.cpp

@@ -0,0 +1,148 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Hardware and software SPI implementations are included in this file.
+ *
+ * Control of the slave select pin(s) is handled by the calling routines and
+ * SAMD21 let hardware SPI handling to remove SS from its logic.
+ */
+
+#ifdef __SAMD21__
+
+// --------------------------------------------------------------------------
+// Includes
+// --------------------------------------------------------------------------
+
+#include "../../inc/MarlinConfig.h"
+#include <SPI.h>
+
+// --------------------------------------------------------------------------
+// Public functions
+// --------------------------------------------------------------------------
+
+#if EITHER(SOFTWARE_SPI, FORCE_SOFT_SPI)
+
+  // ------------------------
+  // Software SPI
+  // ------------------------
+  #error "Software SPI not supported for SAMD21. Use Hardware SPI."
+
+#else // !SOFTWARE_SPI
+
+  static SPISettings spiConfig;
+
+  // ------------------------
+  // Hardware SPI
+  // ------------------------
+  void spiBegin() {
+    spiInit(SPI_HALF_SPEED);
+  }
+
+  void spiInit(uint8_t spiRate) {
+    // Use datarates Marlin uses
+    uint32_t clock;
+    switch (spiRate) {
+      case SPI_FULL_SPEED:      clock = 8000000; break;
+      case SPI_HALF_SPEED:      clock = 4000000; break;
+      case SPI_QUARTER_SPEED:   clock = 2000000; break;
+      case SPI_EIGHTH_SPEED:    clock = 1000000; break;
+      case SPI_SIXTEENTH_SPEED: clock =  500000; break;
+      case SPI_SPEED_5:         clock =  250000; break;
+      case SPI_SPEED_6:         clock =  125000; break;
+      default:                  clock = 4000000; break; // Default from the SPI library
+    }
+    spiConfig = SPISettings(clock, MSBFIRST, SPI_MODE0);
+    SPI.begin();
+  }
+
+  /**
+   * @brief  Receives a single byte from the SPI port.
+   *
+   * @return Byte received
+   *
+   * @details
+   */
+  uint8_t spiRec() {
+    SPI.beginTransaction(spiConfig);
+    uint8_t returnByte = SPI.transfer(0xFF);
+    SPI.endTransaction();
+    return returnByte;
+  }
+
+  /**
+   * @brief  Receives a number of bytes from the SPI port to a buffer
+   *
+   * @param  buf   Pointer to starting address of buffer to write to.
+   * @param  nbyte Number of bytes to receive.
+   * @return Nothing
+   */
+  void spiRead(uint8_t *buf, uint16_t nbyte) {
+    if (nbyte == 0) return;
+    memset(buf, 0xFF, nbyte);
+
+    SPI.beginTransaction(spiConfig);
+    SPI.transfer(buf, nbyte);
+    SPI.endTransaction();
+
+  }
+
+  /**
+   * @brief  Sends a single byte on SPI port
+   *
+   * @param  b Byte to send
+   *
+   * @details
+   */
+  void spiSend(uint8_t b) {
+    SPI.beginTransaction(spiConfig);
+    SPI.transfer(b);
+    SPI.endTransaction();
+  }
+
+  /**
+   * @brief  Write token and then write from 512 byte buffer to SPI (for SD card)
+   *
+   * @param  buf   Pointer with buffer start address
+   * @return Nothing
+   *
+   * @details Uses DMA
+   */
+  void spiSendBlock(uint8_t token, const uint8_t *buf) {
+    SPI.beginTransaction(spiConfig);
+    SPI.transfer(token);
+    SPI.transfer((uint8_t*)buf, 512);
+    SPI.endTransaction();
+  }
+
+  void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) {
+    spiConfig = SPISettings(spiClock, (BitOrder)bitOrder, dataMode);
+    SPI.beginTransaction(spiConfig);
+  }
+#endif // !SOFTWARE_SPI
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/MarlinSPI.h

@@ -0,0 +1,31 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once
+
+#include <SPI.h>
+
+using MarlinSPI = SPIClass;

Marlin/src/HAL/SAMD21/QSPIFlash.cpp

@@ -0,0 +1,82 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(QSPI_EEPROM)
+
+#include "QSPIFlash.h"
+
+#define INVALID_ADDR    0xFFFFFFFF
+#define SECTOR_OF(a)    (a & ~(SFLASH_SECTOR_SIZE - 1))
+#define OFFSET_OF(a)    (a & (SFLASH_SECTOR_SIZE - 1))
+
+Adafruit_SPIFlashBase * QSPIFlash::_flashBase = nullptr;
+uint8_t QSPIFlash::_buf[SFLASH_SECTOR_SIZE];
+uint32_t QSPIFlash::_addr = INVALID_ADDR;
+
+void QSPIFlash::begin() {
+  if (_flashBase) return;
+
+  _flashBase = new Adafruit_SPIFlashBase(new Adafruit_FlashTransport_QSPI());
+  _flashBase->begin(nullptr);
+}
+
+size_t QSPIFlash::size() {
+  return _flashBase->size();
+}
+
+uint8_t QSPIFlash::readByte(const uint32_t address) {
+  if (SECTOR_OF(address) == _addr) return _buf[OFFSET_OF(address)];
+
+  return _flashBase->read8(address);
+}
+
+void QSPIFlash::writeByte(const uint32_t address, const uint8_t value) {
+  uint32_t const sector_addr = SECTOR_OF(address);
+
+  // Page changes, flush old and update new cache
+  if (sector_addr != _addr) {
+    flush();
+    _addr = sector_addr;
+
+    // read a whole page from flash
+    _flashBase->readBuffer(sector_addr, _buf, SFLASH_SECTOR_SIZE);
+  }
+
+  _buf[OFFSET_OF(address)] = value;
+}
+
+void QSPIFlash::flush() {
+  if (_addr == INVALID_ADDR) return;
+
+  _flashBase->eraseSector(_addr / SFLASH_SECTOR_SIZE);
+  _flashBase->writeBuffer(_addr, _buf, SFLASH_SECTOR_SIZE);
+
+  _addr = INVALID_ADDR;
+}
+
+#endif // QSPI_EEPROM

Marlin/src/HAL/SAMD21/QSPIFlash.h

@@ -0,0 +1,49 @@
+/**
+ * @file QSPIFlash.h
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach and Dean Miller for Adafruit Industries LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * Derived from Adafruit_SPIFlash class with no SdFat references
+ */
+#pragma once
+
+#include <Adafruit_SPIFlashBase.h>
+
+// This class extends Adafruit_SPIFlashBase by adding caching support.
+//
+// This class will use 4096 Bytes of RAM as a block cache.
+class QSPIFlash {
+  public:
+    static void begin();
+    static size_t size();
+    static uint8_t readByte(const uint32_t address);
+    static void writeByte(const uint32_t address, const uint8_t v);
+    static void flush();
+
+  private:
+    static Adafruit_SPIFlashBase * _flashBase;
+    static uint8_t _buf[SFLASH_SECTOR_SIZE];
+    static uint32_t _addr;
+};
+
+extern QSPIFlash qspi;

Marlin/src/HAL/SAMD21/SAMD21.h

@@ -0,0 +1,66 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+#define SYNC(sc)    while (sc) {  \
+                      asm("");    \
+                    }
+
+// Get SAMD port/pin from specified arduino pin
+#define GET_SAMD_PORT(P)    _GET_SAMD_PORT(PIN_TO_SAMD_PIN(P))
+#define GET_SAMD_PIN(P)     _GET_SAMD_PIN(PIN_TO_SAMD_PIN(P))
+
+// Get external interrupt line associated to specified arduino pin
+#define PIN_TO_EILINE(P)    _SAMDPORTPIN_TO_EILINE(GET_SAMD_PORT(P), GET_SAMD_PIN(P))
+
+// Get adc/ain associated to specified arduino pin
+#define PIN_TO_ADC(P)       (ANAPIN_TO_ADCAIN(P) >> 8)
+
+// Private defines
+#define PIN_TO_SAMD_PIN(P)    DIO##P##_PIN
+
+#define _GET_SAMD_PORT(P)     ((P) >> 5)
+#define _GET_SAMD_PIN(P)      ((P) & 0x1F)
+
+// Get external interrupt line
+#define _SAMDPORTPIN_TO_EILINE(P,B)   ((P == 0 && WITHIN(B, 0, 31) && B != 26 && B != 28 && B != 29) ? (B) & 0xF    \
+                                       : (P == 1 && (WITHIN(B, 0, 25) || WITHIN(B, 30, 31))) ? (B) & 0xF                      \
+                                       : (P == 1 && WITHIN(B, 26, 29)) ? 12 + (B) - 26                                        \
+                                       : (P == 2 && (WITHIN(B, 0, 6) || WITHIN(B, 10, 31)) && B != 29) ? (B) & 0xF            \
+                                       : (P == 2 && B == 7) ? 9                                                               \
+                                       : (P == 3 && WITHIN(B, 0, 1)) ? (B)                                                    \
+                                       : (P == 3 && WITHIN(B, 8, 12)) ? 3 + (B) - 8                                           \
+                                       : (P == 3 && WITHIN(B, 20, 21)) ? 10 + (B) - 20                                        \
+                                       : -1)
+
+
+
+#define A2_AIN 3
+#define A3_AIN 4
+#define A4_AIN 5
+#define PIN_TO_AIN(P)    A##P##_AIN
+#define AIN_TO_RESULT(P) ( (P - HAL_ADC_AIN_START == HAL_ADC_AIN_NUM_SENSORS-1) ? 0 :  (P - HAL_ADC_AIN_START + 1) )

Marlin/src/HAL/SAMD21/Servo.cpp

@@ -0,0 +1,220 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * This comes from Arduino library which at the moment is buggy and uncompilable
+ */
+
+#ifdef __SAMD21__
+
+#include "../../inc/MarlinConfig.h"
+
+#if HAS_SERVOS
+
+#include "../shared/servo.h"
+#include "../shared/servo_private.h"
+#include "SAMD21.h"
+
+#define __TC_GCLK_ID(t)         TC##t##_GCLK_ID
+#define _TC_GCLK_ID(t)          __TC_GCLK_ID(t)
+#define TC_GCLK_ID              _TC_GCLK_ID(SERVO_TC)
+
+#define _TC_PRESCALER(d)        TC_CTRLA_PRESCALER_DIV##d##_Val
+#define TC_PRESCALER(d)         _TC_PRESCALER(d)
+
+#define __SERVO_IRQn(t)         TC##t##_IRQn
+#define _SERVO_IRQn(t)          __SERVO_IRQn(t)
+#define SERVO_IRQn              _SERVO_IRQn(SERVO_TC)
+
+#define HAL_SERVO_TIMER_ISR()   TC_HANDLER(SERVO_TC)
+
+#define TIMER_TCCHANNEL(t)      ((t) & 1)
+#define TC_COUNTER_START_VAL    0xFFFF
+
+
+static volatile int8_t currentServoIndex[_Nbr_16timers];    // index for the servo being pulsed for each timer (or -1 if refresh interval)
+
+FORCE_INLINE static uint16_t getTimerCount() {
+  Tcc * const tc = timer_config[SERVO_TC].pTcc;
+
+  tc->CTRLBSET.reg = TCC_CTRLBCLR_CMD_READSYNC;
+  SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+
+  return tc->COUNT.bit.COUNT;
+}
+
+// ----------------------------
+// Interrupt handler for the TC
+// ----------------------------
+HAL_SERVO_TIMER_ISR() {
+  Tcc * const tc = timer_config[SERVO_TC].pTcc;
+  const timer16_Sequence_t timer =
+    #ifndef _useTimer1
+      _timer2
+    #elif !defined(_useTimer2)
+      _timer1
+    #else
+      (tc->INTFLAG.reg & tc->INTENSET.reg & TC_INTFLAG_MC0) ? _timer1 : _timer2
+    #endif
+  ;
+  const uint8_t tcChannel = TIMER_TCCHANNEL(timer);
+
+  int8_t cho = currentServoIndex[timer];                // Handle the prior servo first
+  if (cho < 0) {                                        // Servo -1 indicates the refresh interval completed...
+    #if defined(_useTimer1) && defined(_useTimer2)
+      if (currentServoIndex[timer ^ 1] >= 0) {
+        // Wait for both channels
+        // Clear the interrupt
+        tc->INTFLAG.reg = (tcChannel == 0) ? TC_INTFLAG_MC0 : TC_INTFLAG_MC1;
+        return;
+      }
+    #endif
+    tc->COUNT.reg = TC_COUNTER_START_VAL;       // ...so reset the timer
+    SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+  }
+  else if (SERVO_INDEX(timer, cho) < ServoCount)        // prior channel handled?
+    digitalWrite(SERVO(timer, cho).Pin.nbr, LOW);       // pulse the prior channel LOW
+
+  currentServoIndex[timer] = ++cho;                     // go to the next channel (or 0)
+  if (cho < SERVOS_PER_TIMER && SERVO_INDEX(timer, cho) < ServoCount) {
+    if (SERVO(timer, cho).Pin.isActive)                 // activated?
+      digitalWrite(SERVO(timer, cho).Pin.nbr, HIGH);    // yes: pulse HIGH
+
+    tc->CC[tcChannel].reg = getTimerCount() - (uint16_t)SERVO(timer, cho).ticks;
+  }
+  else {
+    // finished all channels so wait for the refresh period to expire before starting over
+    currentServoIndex[timer] = -1;                                          // reset the timer COUNT.reg on the next call
+    const uint16_t cval = getTimerCount() - 256 / (SERVO_TIMER_PRESCALER),  // allow 256 cycles to ensure the next CV not missed
+                   ival = (TC_COUNTER_START_VAL) - (uint16_t)usToTicks(REFRESH_INTERVAL); // at least REFRESH_INTERVAL has elapsed
+    tc->CC[tcChannel].reg = min(cval, ival);
+  }
+  if (tcChannel == 0) {
+    SYNC(tc->SYNCBUSY.bit.CC0);
+    tc->INTFLAG.reg = TC_INTFLAG_MC0; // Clear the interrupt
+  }
+  else {
+    SYNC(tc->SYNCBUSY.bit.CC1);
+    tc->INTFLAG.reg = TC_INTFLAG_MC1; // Clear the interrupt
+  }
+}
+
+void initISR(const timer16_Sequence_t timer) {
+  Tcc * const tc = timer_config[SERVO_TC].pTcc;
+  const uint8_t tcChannel = TIMER_TCCHANNEL(timer);
+
+  static bool initialized = false;  // Servo TC has been initialized
+  if (!initialized) {
+    NVIC_DisableIRQ(SERVO_IRQn);
+
+    // Disable the timer
+    tc->CTRLA.bit.ENABLE = false;
+    SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+
+    // Select GCLK0 as timer/counter input clock source
+    GCLK->CLKCTRL.reg =(GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_ID(TCC0_GCLK_ID));
+    SYNC (GCLK->STATUS.bit.SYNCBUSY);
+
+    // Reset the timer
+    tc->CTRLA.bit.SWRST = true;
+    SYNC(tc->CTRLA.bit.SWRST);
+
+    // Set timer counter mode to 16 bits
+    tc->CTRLA.reg = TC_CTRLA_MODE_COUNT16;
+
+    // Set timer counter mode as normal PWM
+    tc->WAVE.bit.WAVEGEN = TCC_WAVE_WAVEGEN_NPWM_Val;
+
+    // Set the prescaler factor
+    tc->CTRLA.bit.PRESCALER = TC_PRESCALER(SERVO_TIMER_PRESCALER);
+
+    // Count down
+    tc->CTRLBSET.reg = TCC_CTRLBCLR_DIR;
+    SYNC(tc->SYNCBUSY.bit.CTRLB);
+
+    // Reset all servo indexes
+    memset((void *)currentServoIndex, 0xFF, sizeof(currentServoIndex));
+
+    // Configure interrupt request
+    NVIC_ClearPendingIRQ(SERVO_IRQn);
+    NVIC_SetPriority(SERVO_IRQn, 5);
+    NVIC_EnableIRQ(SERVO_IRQn);
+
+    initialized = true;
+  }
+
+  if (!tc->CTRLA.bit.ENABLE) {
+    // Reset the timer counter
+    tc->COUNT.reg = TC_COUNTER_START_VAL;
+    SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+
+    // Enable the timer and start it
+    tc->CTRLA.bit.ENABLE = true;
+    SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+  }
+  // First interrupt request after 1 ms
+  tc->CC[tcChannel].reg = getTimerCount() - (uint16_t)usToTicks(1000UL);
+
+  if (tcChannel == 0 ) {
+    SYNC(tc->SYNCBUSY.bit.CC0);
+
+    // Clear pending match interrupt
+    tc->INTFLAG.reg = TC_INTENSET_MC0;
+    // Enable the match channel interrupt request
+    tc->INTENSET.reg = TC_INTENSET_MC0;
+  }
+  else {
+    SYNC(tc->SYNCBUSY.bit.CC1);
+
+    // Clear pending match interrupt
+    tc->INTFLAG.reg = TC_INTENSET_MC1;
+    // Enable the match channel interrupt request
+    tc->INTENSET.reg = TC_INTENSET_MC1;
+  }
+}
+
+void finISR(const timer16_Sequence_t timer_index) {
+  Tcc * const tc = timer_config[SERVO_TC].pTcc;
+  const uint8_t tcChannel = TIMER_TCCHANNEL(timer_index);
+
+  // Disable the match channel interrupt request
+  tc->INTENCLR.reg = (tcChannel == 0) ? TC_INTENCLR_MC0 : TC_INTENCLR_MC1;
+
+  if (true
+    #if defined(_useTimer1) && defined(_useTimer2)
+      && (tc->INTENCLR.reg & (TC_INTENCLR_MC0|TC_INTENCLR_MC1)) == 0
+    #endif
+  ) {
+    // Disable the timer if not used
+    tc->CTRLA.bit.ENABLE = false;
+    SYNC(tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+  }
+}
+
+#endif // HAS_SERVOS
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/ServoTimers.h

@@ -0,0 +1,45 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+#define _useTimer1
+#define _useTimer2
+
+#define TRIM_DURATION           5   // compensation ticks to trim adjust for digitalWrite delays
+#define SERVO_TIMER_PRESCALER   64  // timer prescaler factor to 64 (avoid overflowing 16-bit clock counter, at 120MHz this is 1831 ticks per millisecond
+
+#define SERVO_TC                3
+
+typedef enum {
+  #ifdef _useTimer1
+    _timer1,
+  #endif
+  #ifdef _useTimer2
+    _timer2,
+  #endif
+  _Nbr_16timers
+} timer16_Sequence_t;

Marlin/src/HAL/SAMD21/eeprom_flash.cpp

@@ -0,0 +1,141 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#ifdef __SAMD21__
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(FLASH_EEPROM_EMULATION)
+
+#define TOTAL_FLASH_SIZE (MARLIN_EEPROM_SIZE+255)/256*256
+
+/* reserve flash memory */
+static const uint8_t flashdata[TOTAL_FLASH_SIZE]  __attribute__((__aligned__(256))) { }; \
+
+#include "../shared/eeprom_api.h"
+
+size_t PersistentStore::capacity() {
+  return MARLIN_EEPROM_SIZE;
+ /* const uint8_t psz = NVMCTRL->SEESTAT.bit.PSZ,
+                sblk = NVMCTRL->SEESTAT.bit.SBLK;
+
+  return   (!psz && !sblk)         ? 0
+         : (psz <= 2)              ? (0x200 << psz)
+         : (sblk == 1 || psz == 3) ?  4096
+         : (sblk == 2 || psz == 4) ?  8192
+         : (sblk <= 4 || psz == 5) ? 16384
+         : (sblk >= 9 && psz == 7) ? 65536
+                                   : 32768;*/
+}
+
+uint32_t PAGE_SIZE;
+uint32_t ROW_SIZE;
+bool hasWritten = false;
+uint8_t * buffer;
+
+void _erase(const volatile void *flash_ptr) {
+  NVMCTRL->ADDR.reg = ((uint32_t)flash_ptr) / 2;
+  NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_ER;
+  while (!NVMCTRL->INTFLAG.bit.READY) { }
+
+}
+
+void erase(const volatile void *flash_ptr, uint32_t size) {
+  const uint8_t *ptr = (const uint8_t *)flash_ptr;
+  while (size > ROW_SIZE) {
+    _erase(ptr);
+    ptr += ROW_SIZE;
+    size -= ROW_SIZE;
+  }
+  _erase(ptr);
+}
+
+bool PersistentStore::access_start() {
+  /* clear page buffer*/
+  NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_PBC;
+  while (NVMCTRL->INTFLAG.bit.READY == 0) { }
+
+  PAGE_SIZE =  pow(2,3 + NVMCTRL->PARAM.bit.PSZ);
+  ROW_SIZE= PAGE_SIZE * 4;
+  /*NVMCTRL->SEECFG.reg = NVMCTRL_SEECFG_WMODE_BUFFERED;  // Buffered mode and segment reallocation active
+  if (NVMCTRL->SEESTAT.bit.RLOCK)
+    NVMCTRL_CMD(NVMCTRL_CTRLB_CMD_USEE);  */  // Unlock E2P data write access
+  //   erase(&flashdata[0], TOTAL_FLASH_SIZE);
+  return true;
+}
+
+bool PersistentStore::access_finish() {
+  if (hasWritten) {
+    erase(&flashdata[0], TOTAL_FLASH_SIZE);
+
+    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_PBC;
+    while (NVMCTRL->INTFLAG.bit.READY == 0) { }
+
+     NVMCTRL->CTRLB.bit.MANW = 0;
+
+    volatile uint32_t *dst_addr =  (volatile uint32_t *) &flashdata;
+
+    uint32_t *pointer = (uint32_t *) buffer;
+    for (uint32_t i = 0; i < TOTAL_FLASH_SIZE; i+=4) {
+
+      *dst_addr = (uint32_t) *pointer;
+      pointer++;
+      dst_addr ++;
+    }
+
+    // Execute "WP" Write Page
+    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_WP;
+    while (NVMCTRL->INTFLAG.bit.READY == 0) { }
+
+    free(buffer);
+    hasWritten = false;
+  }
+  return true;
+}
+
+bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, uint16_t *crc) {
+  if (!hasWritten) {
+    // init temp buffer
+    buffer = (uint8_t *) malloc(MARLIN_EEPROM_SIZE);
+    hasWritten=true;
+  }
+
+  memcpy(buffer+pos,value,size);
+  pos += size;
+  return false;
+}
+
+bool PersistentStore::read_data(int &pos, uint8_t *value, size_t size, uint16_t *crc, const bool writing/*=true*/) {
+  volatile uint8_t *dst_addr =  (volatile uint8_t *) &flashdata;
+  dst_addr += pos;
+
+  memcpy(value,(const void *) dst_addr,size);
+  pos += size;
+  return false;
+}
+
+#endif // FLASH_EEPROM_EMULATION
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/eeprom_qspi.cpp

@@ -0,0 +1,79 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#ifdef __SAMD21__
+
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(QSPI_EEPROM)
+
+#error "QSPI_EEPROM emulation Not implemented on SAMD21"
+
+#include "../shared/eeprom_api.h"
+
+#include "QSPIFlash.h"
+
+static bool initialized;
+
+size_t PersistentStore::capacity() { return qspi.size(); }
+
+bool PersistentStore::access_start() {
+  if (!initialized) {
+    qspi.begin();
+    initialized = true;
+  }
+  return true;
+}
+
+bool PersistentStore::access_finish() {
+  qspi.flush();
+  return true;
+}
+
+bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, uint16_t *crc) {
+  while (size--) {
+    const uint8_t v = *value;
+    qspi.writeByte(pos, v);
+    crc16(crc, &v, 1);
+    pos++;
+    value++;
+  }
+  return false;
+}
+
+bool PersistentStore::read_data(int &pos, uint8_t *value, size_t size, uint16_t *crc, const bool writing/*=true*/) {
+  while (size--) {
+    uint8_t c = qspi.readByte(pos);
+    if (writing) *value = c;
+    crc16(crc, &c, 1);
+    pos++;
+    value++;
+  }
+  return false;
+}
+
+#endif // QSPI_EEPROM
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/eeprom_wired.cpp

@@ -0,0 +1,82 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#ifdef __SAMD21__
+
+#include "../../inc/MarlinConfig.h"
+
+#if USE_WIRED_EEPROM
+
+#error "USE_WIRED_EEPROM emulation Not implemented on SAMD21"
+/**
+ * PersistentStore for Arduino-style EEPROM interface
+ * with simple implementations supplied by Marlin.
+ */
+
+#include "../shared/eeprom_if.h"
+#include "../shared/eeprom_api.h"
+
+#ifndef MARLIN_EEPROM_SIZE
+  #error "MARLIN_EEPROM_SIZE is required for I2C / SPI EEPROM."
+#endif
+size_t PersistentStore::capacity()    { return MARLIN_EEPROM_SIZE; }
+
+bool PersistentStore::access_start()  { eeprom_init(); return true; }
+bool PersistentStore::access_finish() { return true; }
+
+bool PersistentStore::write_data(int &pos, const uint8_t *value, size_t size, uint16_t *crc) {
+  uint16_t written = 0;
+  while (size--) {
+    const uint8_t v = *value;
+    uint8_t * const p = (uint8_t * const)pos;
+    if (v != eeprom_read_byte(p)) { // EEPROM has only ~100,000 write cycles, so only write bytes that have changed!
+      eeprom_write_byte(p, v);
+      if (++written & 0x7F) delay(2); else safe_delay(2); // Avoid triggering watchdog during long EEPROM writes
+      if (eeprom_read_byte(p) != v) {
+        SERIAL_ECHO_MSG(STR_ERR_EEPROM_WRITE);
+        return true;
+      }
+    }
+    crc16(crc, &v, 1);
+    pos++;
+    value++;
+  }
+  return false;
+}
+
+bool PersistentStore::read_data(int &pos, uint8_t *value, size_t size, uint16_t *crc, const bool writing/*=true*/) {
+  while (size--) {
+    uint8_t c = eeprom_read_byte((uint8_t*)pos);
+    if (writing) *value = c;
+    crc16(crc, &c, 1);
+    pos++;
+    value++;
+  }
+  return false;
+}
+
+#endif // USE_WIRED_EEPROM
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/endstop_interrupts.h

@@ -0,0 +1,253 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Endstop interrupts for ATMEL SAMD21 based targets.
+ *
+ * On SAMD21, all pins support external interrupt capability.
+ * Any pin can be used for external interrupts, but there are some restrictions.
+ * At most 16 different external interrupts can be used at one time.
+ * Further, you can’t just pick any 16 pins to use. This is because every pin on the SAMD21
+ * connects to what is called an EXTINT line, and only one pin per EXTINT line can be used for external
+ * interrupts at a time
+ */
+
+/**
+ * Endstop Interrupts
+ *
+ * Without endstop interrupts the endstop pins must be polled continually in
+ * the temperature-ISR via endstops.update(), most of the time finding no change.
+ * With this feature endstops.update() is called only when we know that at
+ * least one endstop has changed state, saving valuable CPU cycles.
+ *
+ * This feature only works when all used endstop pins can generate an 'external interrupt'.
+ *
+ * Test whether pins issue interrupts on your board by flashing 'pin_interrupt_test.ino'.
+ * (Located in Marlin/buildroot/share/pin_interrupt_test/pin_interrupt_test.ino)
+ */
+
+#include "../../module/endstops.h"
+
+#define MATCH_EILINE(P1,P2) (P1 != P2 && PIN_TO_EILINE(P1) == PIN_TO_EILINE(P2))
+#define MATCH_X_MAX_EILINE(P)   TERN0(HAS_X_MAX,  DEFER4(MATCH_EILINE)(P, X_MAX_PIN))
+#define MATCH_X_MIN_EILINE(P)   TERN0(HAS_X_MIN,  DEFER4(MATCH_EILINE)(P, X_MIN_PIN))
+#define MATCH_Y_MAX_EILINE(P)   TERN0(HAS_Y_MAX,  DEFER4(MATCH_EILINE)(P, Y_MAX_PIN))
+#define MATCH_Y_MIN_EILINE(P)   TERN0(HAS_Y_MIN,  DEFER4(MATCH_EILINE)(P, Y_MIN_PIN))
+#define MATCH_Z_MAX_EILINE(P)   TERN0(HAS_Z_MAX,  DEFER4(MATCH_EILINE)(P, Z_MAX_PIN))
+#define MATCH_Z_MIN_EILINE(P)   TERN0(HAS_Z_MIN,  DEFER4(MATCH_EILINE)(P, Z_MIN_PIN))
+#define MATCH_I_MAX_EILINE(P)   TERN0(HAS_I_MAX,  DEFER4(MATCH_EILINE)(P, I_MAX_PIN))
+#define MATCH_I_MIN_EILINE(P)   TERN0(HAS_I_MIN,  DEFER4(MATCH_EILINE)(P, I_MIN_PIN))
+#define MATCH_J_MAX_EILINE(P)   TERN0(HAS_J_MAX,  DEFER4(MATCH_EILINE)(P, J_MAX_PIN))
+#define MATCH_J_MIN_EILINE(P)   TERN0(HAS_J_MIN,  DEFER4(MATCH_EILINE)(P, J_MIN_PIN))
+#define MATCH_K_MAX_EILINE(P)   TERN0(HAS_K_MAX,  DEFER4(MATCH_EILINE)(P, K_MAX_PIN))
+#define MATCH_K_MIN_EILINE(P)   TERN0(HAS_K_MIN,  DEFER4(MATCH_EILINE)(P, K_MIN_PIN))
+#define MATCH_U_MAX_EILINE(P)   TERN0(HAS_U_MAX,  DEFER4(MATCH_EILINE)(P, U_MAX_PIN))
+#define MATCH_U_MIN_EILINE(P)   TERN0(HAS_U_MIN,  DEFER4(MATCH_EILINE)(P, U_MIN_PIN))
+#define MATCH_V_MAX_EILINE(P)   TERN0(HAS_V_MAX,  DEFER4(MATCH_EILINE)(P, V_MAX_PIN))
+#define MATCH_V_MIN_EILINE(P)   TERN0(HAS_V_MIN,  DEFER4(MATCH_EILINE)(P, V_MIN_PIN))
+#define MATCH_W_MAX_EILINE(P)   TERN0(HAS_W_MAX,  DEFER4(MATCH_EILINE)(P, W_MAX_PIN))
+#define MATCH_W_MIN_EILINE(P)   TERN0(HAS_W_MIN,  DEFER4(MATCH_EILINE)(P, W_MIN_PIN))
+#define MATCH_Z2_MAX_EILINE(P)  TERN0(HAS_Z2_MAX, DEFER4(MATCH_EILINE)(P, Z2_MAX_PIN))
+#define MATCH_Z2_MIN_EILINE(P)  TERN0(HAS_Z2_MIN, DEFER4(MATCH_EILINE)(P, Z2_MIN_PIN))
+#define MATCH_Z3_MAX_EILINE(P)  TERN0(HAS_Z3_MAX, DEFER4(MATCH_EILINE)(P, Z3_MAX_PIN))
+#define MATCH_Z3_MIN_EILINE(P)  TERN0(HAS_Z3_MIN, DEFER4(MATCH_EILINE)(P, Z3_MIN_PIN))
+#define MATCH_Z4_MAX_EILINE(P)  TERN0(HAS_Z4_MAX, DEFER4(MATCH_EILINE)(P, Z4_MAX_PIN))
+#define MATCH_Z4_MIN_EILINE(P)  TERN0(HAS_Z4_MIN, DEFER4(MATCH_EILINE)(P, Z4_MIN_PIN))
+#define MATCH_Z_MIN_PROBE_EILINE(P) TERN0(HAS_Z_MIN_PROBE_PIN, DEFER4(MATCH_EILINE)(P, Z_MIN_PROBE_PIN))
+
+#define AVAILABLE_EILINE(P) ( PIN_TO_EILINE(P) != -1    \
+  && !MATCH_X_MAX_EILINE(P) && !MATCH_X_MIN_EILINE(P)   \
+  && !MATCH_Y_MAX_EILINE(P) && !MATCH_Y_MIN_EILINE(P)   \
+  && !MATCH_Z_MAX_EILINE(P) && !MATCH_Z_MIN_EILINE(P)   \
+  && !MATCH_I_MAX_EILINE(P) && !MATCH_I_MIN_EILINE(P)   \
+  && !MATCH_J_MAX_EILINE(P) && !MATCH_J_MIN_EILINE(P)   \
+  && !MATCH_K_MAX_EILINE(P) && !MATCH_K_MIN_EILINE(P)   \
+  && !MATCH_U_MAX_EILINE(P) && !MATCH_U_MIN_EILINE(P)   \
+  && !MATCH_V_MAX_EILINE(P) && !MATCH_V_MIN_EILINE(P)   \
+  && !MATCH_W_MAX_EILINE(P) && !MATCH_W_MIN_EILINE(P)   \
+  && !MATCH_Z2_MAX_EILINE(P) && !MATCH_Z2_MIN_EILINE(P) \
+  && !MATCH_Z3_MAX_EILINE(P) && !MATCH_Z3_MIN_EILINE(P) \
+  && !MATCH_Z4_MAX_EILINE(P) && !MATCH_Z4_MIN_EILINE(P) \
+  && !MATCH_Z_MIN_PROBE_EILINE(P) )
+
+// One ISR for all EXT-Interrupts
+void endstop_ISR() { endstops.update(); }
+
+void setup_endstop_interrupts() {
+  #define _ATTACH(P) attachInterrupt(P, endstop_ISR, CHANGE)
+  #if HAS_X_MAX
+    #if !AVAILABLE_EILINE(X_MAX_PIN)
+      #error "X_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(X_MAX_PIN);
+  #endif
+  #if HAS_X_MIN
+    #if !AVAILABLE_EILINE(X_MIN_PIN)
+      #error "X_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(X_MIN_PIN);
+  #endif
+  #if HAS_Y_MAX
+    #if !AVAILABLE_EILINE(Y_MAX_PIN)
+      #error "Y_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Y_MAX_PIN);
+  #endif
+  #if HAS_Y_MIN
+    #if !AVAILABLE_EILINE(Y_MIN_PIN)
+      #error "Y_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Y_MIN_PIN);
+  #endif
+  #if HAS_Z_MAX
+    #if !AVAILABLE_EILINE(Z_MAX_PIN)
+      #error "Z_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z_MAX_PIN);
+  #endif
+  #if HAS_Z_MIN
+    #if !AVAILABLE_EILINE(Z_MIN_PIN)
+      #error "Z_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z_MIN_PIN);
+  #endif
+  #if HAS_Z2_MAX
+    #if !AVAILABLE_EILINE(Z2_MAX_PIN)
+      #error "Z2_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z2_MAX_PIN);
+  #endif
+  #if HAS_Z2_MIN
+    #if !AVAILABLE_EILINE(Z2_MIN_PIN)
+      #error "Z2_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z2_MIN_PIN);
+  #endif
+  #if HAS_Z3_MAX
+    #if !AVAILABLE_EILINE(Z3_MAX_PIN)
+      #error "Z3_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z3_MAX_PIN);
+  #endif
+  #if HAS_Z3_MIN
+    #if !AVAILABLE_EILINE(Z3_MIN_PIN)
+      #error "Z3_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z3_MIN_PIN);
+  #endif
+  #if HAS_Z4_MAX
+    #if !AVAILABLE_EILINE(Z4_MAX_PIN)
+      #error "Z4_MAX_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z4_MAX_PIN);
+  #endif
+  #if HAS_Z4_MIN
+    #if !AVAILABLE_EILINE(Z4_MIN_PIN)
+      #error "Z4_MIN_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z4_MIN_PIN);
+  #endif
+  #if HAS_Z_MIN_PROBE_PIN
+    #if !AVAILABLE_EILINE(Z_MIN_PROBE_PIN)
+      #error "Z_MIN_PROBE_PIN has no EXTINT line available."
+    #endif
+    _ATTACH(Z_MIN_PROBE_PIN);
+  #endif
+  #if HAS_I_MAX
+    #if !AVAILABLE_EILINE(I_MAX_PIN)
+      #error "I_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(I_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_I_MIN
+    #if !AVAILABLE_EILINE(I_MIN_PIN)
+      #error "I_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(I_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_J_MAX
+    #if !AVAILABLE_EILINE(J_MAX_PIN)
+      #error "J_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(J_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_J_MIN
+    #if !AVAILABLE_EILINE(J_MIN_PIN)
+      #error "J_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(J_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_K_MAX
+    #if !AVAILABLE_EILINE(K_MAX_PIN)
+      #error "K_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(K_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_K_MIN
+    #if !AVAILABLE_EILINE(K_MIN_PIN)
+      #error "K_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(K_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_U_MAX
+    #if !AVAILABLE_EILINE(U_MAX_PIN)
+      #error "U_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(U_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_U_MIN
+    #if !AVAILABLE_EILINE(U_MIN_PIN)
+      #error "U_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(U_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_V_MAX
+    #if !AVAILABLE_EILINE(V_MAX_PIN)
+      #error "V_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(V_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_V_MIN
+    #if !AVAILABLE_EILINE(V_MIN_PIN)
+      #error "V_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(V_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_W_MAX
+    #if !AVAILABLE_EILINE(W_MAX_PIN)
+      #error "W_MAX_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(W_MAX_PIN, endstop_ISR, CHANGE);
+  #endif
+  #if HAS_W_MIN
+    #if !AVAILABLE_EILINE(W_MIN_PIN)
+      #error "W_MIN_PIN has no EXTINT line available."
+    #endif
+    attachInterrupt(W_MIN_PIN, endstop_ISR, CHANGE);
+  #endif
+}

Marlin/src/HAL/SAMD21/fastio.h

@@ -0,0 +1,216 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Fast IO functions for SAMD21
+ */
+
+#include "SAMD21.h"
+
+/**
+ * Utility functions
+ */
+
+#ifndef MASK
+  #define MASK(PIN) _BV(PIN)
+#endif
+
+/**
+ * Magic I/O routines
+ *
+ * Now you can simply SET_OUTPUT(IO); WRITE(IO, HIGH); WRITE(IO, LOW);
+ */
+
+// Read a pin
+#define READ(IO)        ((PORT->Group[(EPortType)GET_SAMD_PORT(IO)].IN.reg & MASK(GET_SAMD_PIN(IO))) != 0)
+
+// Write to a pin
+#define WRITE(IO,V)     do{                                                     \
+                          const EPortType port = (EPortType)GET_SAMD_PORT(IO);  \
+                          const uint32_t mask = MASK(GET_SAMD_PIN(IO));         \
+                                                                                \
+                          if (V) PORT->Group[port].OUTSET.reg = mask;           \
+                          else PORT->Group[port].OUTCLR.reg = mask;             \
+                        }while(0)
+
+// Toggle a pin
+#define TOGGLE(IO)      PORT->Group[(EPortType)GET_SAMD_PORT(IO)].OUTTGL.reg = MASK(GET_SAMD_PIN(IO));
+
+// Set pin as input
+#define SET_INPUT(IO)           do{                                                                 \
+                                  const EPortType port = (EPortType)GET_SAMD_PORT(IO);              \
+                                  const uint32_t pin = GET_SAMD_PIN(IO);                            \
+                                                                                                    \
+                                  PORT->Group[port].PINCFG[pin].reg = (uint8_t)(PORT_PINCFG_INEN);  \
+                                  PORT->Group[port].DIRCLR.reg = MASK(pin);                         \
+                                }while(0)
+// Set pin as input with pullup
+#define SET_INPUT_PULLUP(IO)    do{                                                                                       \
+                                  const EPortType port = (EPortType)GET_SAMD_PORT(IO);                                    \
+                                  const uint32_t pin = GET_SAMD_PIN(IO);                                                  \
+                                  const uint32_t mask = MASK(pin);                                                        \
+                                                                                                                          \
+                                  PORT->Group[port].PINCFG[pin].reg = (uint8_t)(PORT_PINCFG_INEN | PORT_PINCFG_PULLEN);   \
+                                  PORT->Group[port].DIRCLR.reg = mask;                                                    \
+                                  PORT->Group[port].OUTSET.reg = mask;                                                    \
+                                }while(0)
+// Set pin as input with pulldown
+#define SET_INPUT_PULLDOWN(IO)  do{                                                                                       \
+                                  const EPortType port = (EPortType)GET_SAMD_PORT(IO);                                    \
+                                  const uint32_t pin = GET_SAMD_PIN(IO);                                                  \
+                                  const uint32_t mask = MASK(pin);                                                        \
+                                                                                                                          \
+                                  PORT->Group[port].PINCFG[pin].reg = (uint8_t)(PORT_PINCFG_INEN | PORT_PINCFG_PULLEN);   \
+                                  PORT->Group[port].DIRCLR.reg = mask;                                                    \
+                                  PORT->Group[port].OUTCLR.reg = mask;                                                    \
+                                }while(0)
+// Set pin as output (push pull)
+#define SET_OUTPUT(IO)          do{                                                                 \
+                                  const EPortType port = (EPortType)GET_SAMD_PORT(IO);              \
+                                  const uint32_t pin = GET_SAMD_PIN(IO);                            \
+                                                                                                    \
+                                  PORT->Group[port].DIRSET.reg = MASK(pin);                         \
+                                  PORT->Group[port].PINCFG[pin].reg = 0;                            \
+                                }while(0)
+// Set pin as output (open drain)
+#define SET_OUTPUT_OD(IO)       do{                                                                   \
+                                  const EPortType port = (EPortType)GET_SAMD_PORT(IO);                \
+                                  const uint32_t pin = GET_SAMD_PIN(IO);                              \
+                                                                                                      \
+                                  PORT->Group[port].PINCFG[pin].reg = (uint8_t)(PORT_PINCFG_PULLEN);  \
+                                  PORT->Group[port].DIRCLR.reg = MASK(pin);                           \
+                                }while(0)
+// Set pin as PWM (push pull)
+#define SET_PWM                 SET_OUTPUT
+// Set pin as PWM (open drain)
+#define SET_PWM_OD              SET_OUTPUT_OD
+
+// check if pin is an output
+#define IS_OUTPUT(IO)            ((PORT->Group[(EPortType)GET_SAMD_PORT(IO)].DIR.reg & MASK(GET_SAMD_PIN(IO))) \
+                                 || (PORT->Group[(EPortType)GET_SAMD_PORT(IO)].PINCFG[GET_SAMD_PIN(IO)].reg & (PORT_PINCFG_INEN | PORT_PINCFG_PULLEN)) == PORT_PINCFG_PULLEN)
+// check if pin is an input
+#define IS_INPUT(IO)            !IS_OUTPUT(IO)
+
+// Shorthand
+#define OUT_WRITE(IO,V)         do{ SET_OUTPUT(IO); WRITE(IO,V); }while(0)
+#define OUT_WRITE_OD(IO,V)      do{ SET_OUTPUT_OD(IO); WRITE(IO,V); }while(0)
+
+// digitalRead/Write wrappers
+#define extDigitalRead(IO)      digitalRead(IO)
+#define extDigitalWrite(IO,V)   digitalWrite(IO,V)
+
+/**
+ * Ports and functions
+ * Added as necessary or if I feel like it- not a comprehensive list!
+ */
+
+/*
+ * Some of these share the same source and so can't be used in the same time
+ */
+#define PWM_PIN(P)        (WITHIN(P, 2, 13) || WITHIN(P, 22, 23) || WITHIN(P, 44, 45) || P == 48)
+
+// Return fulfilled ADCx->INPUTCTRL.reg
+#define PIN_TO_INPUTCTRL(P)     (  (P == 0) ? ADC_INPUTCTRL_MUXPOS_PIN0   \
+                                 : ((P) == 1) ? ADC_INPUTCTRL_MUXPOS_PIN1   \
+                                 : ((P) == 2) ? ADC_INPUTCTRL_MUXPOS_PIN3   \
+                                 : ((P) == 3) ? ADC_INPUTCTRL_MUXPOS_PIN4   \
+                                 : ((P) == 4) ? ADC_INPUTCTRL_MUXPOS_PIN5   \
+                                 : ((P) == 5) ? ADC_INPUTCTRL_MUXPOS_PIN5   \
+                                 : ((P) == 6) ? ADC_INPUTCTRL_MUXPOS_PIN6   \
+                                 : ((P) == 7) ? ADC_INPUTCTRL_MUXPOS_PIN7   \
+                                 : ((P) == 8) ? ADC_INPUTCTRL_MUXPOS_PIN8   \
+                                 : ((P) == 9) ? ADC_INPUTCTRL_MUXPOS_PIN9   \
+                                 : ((P) == 10) ? ADC_INPUTCTRL_MUXPOS_PIN10 \
+                                 : ((P) == 11) ? ADC_INPUTCTRL_MUXPOS_PIN11 \
+                                 : ((P) == 12) ? ADC_INPUTCTRL_MUXPOS_PIN12 \
+                                 : ((P) == 13) ? ADC_INPUTCTRL_MUXPOS_PIN13 \
+                                 : ((P) == 14) ? ADC_INPUTCTRL_MUXPOS_PIN14 \
+                                 : ADC_INPUTCTRL_MUXPOS_PIN15)
+
+#define digitalPinToAnalogInput(P) (WITHIN(P, 67, 74) ? (P) - 67 : WITHIN(P, 54, 61) ? 8 + (P) - 54 : WITHIN(P, 12, 13) ? 16 + (P) - 12 : P == 9 ? 18 : -1)
+
+/**
+ * pins
+ */
+
+// PORTA
+#define DIO28_PIN   PIN_PA02    // A0
+#define DIO56_PIN   PIN_PA03    // A13
+#define DIO31_PIN   PIN_PA04    // A13
+#define DIO32_PIN   PIN_PA05    // A1
+#define DIO8_PIN    PIN_PA06    // A14
+#define DIO9_PIN    PIN_PA07    // A15
+#define DIO4_PIN    PIN_PA08    // A15
+#define DIO3_PIN    PIN_PA09    // A15
+#define DIO1_PIN    PIN_PA10
+#define DIO0_PIN    PIN_PA11
+#define DIO18_PIN   PIN_PA12
+#define DIO52_PIN   PIN_PA13
+#define DIO2_PIN    PIN_PA14
+#define DIO5_PIN    PIN_PA15
+#define DIO11_PIN   PIN_PA16
+#define DIO13_PIN   PIN_PA17
+#define DIO10_PIN   PIN_PA18
+#define DIO12_PIN   PIN_PA19
+#define DIO6_PIN    PIN_PA20
+#define DIO07_PIN   PIN_PA21
+#define DIO34_PIN   PIN_PA22
+#define DIO35_PIN   PIN_PA23
+#define DIO42_PIN   PIN_PA24
+#define DIO43_PIN   PIN_PA25
+
+#define DIO40_PIN   PIN_PA27
+
+#define DIO26_PIN   PIN_PB00
+#define DIO27_PIN   PIN_PB01    // A0
+#define DIO33_PIN   PIN_PB02
+#define DIO39_PIN   PIN_PB03
+#define DIO14_PIN   PIN_PB04
+#define DIO15_PIN   PIN_PB05
+#define DIO16_PIN   PIN_PB06
+#define DIO17_PIN   PIN_PB07
+#define DIO29_PIN   PIN_PB08
+#define DIO30_PIN   PIN_PB09
+#define DIO37_PIN   PIN_PB10
+#define DIO38_PIN   PIN_PB11
+#define DIO36_PIN   PIN_PB12
+#define DIO19_PIN   PIN_PB13
+#define DIO20_PIN   PIN_PB14
+#define DIO21_PIN   PIN_PB15
+#define DIO22_PIN   PIN_PB16
+#define DIO23_PIN   PIN_PB17
+
+#define DIO44_PIN   PIN_PB22
+#define DIO45_PIN   PIN_PB23
+#define DIO24_PIN   PIN_PB30
+#define DIO25_PIN   PIN_PB31
+
+#define DIO53_PIN   PIN_PA21
+#define DIO54_PIN   PIN_PA06
+#define DIO55_PIN   PIN_PA07
+

Marlin/src/HAL/SAMD21/inc/Conditionals_LCD.h

@@ -0,0 +1,31 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once
+
+#if HAS_SPI_TFT || HAS_FSMC_TFT
+  #error "Sorry! TFT displays are not available for HAL/SAMD21."
+#endif

Marlin/src/HAL/SAMD21/inc/Conditionals_adv.h

@@ -0,0 +1,27 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once

Marlin/src/HAL/SAMD21/inc/Conditionals_post.h

@@ -0,0 +1,33 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once
+
+#if USE_FALLBACK_EEPROM
+  #define FLASH_EEPROM_EMULATION
+#elif EITHER(I2C_EEPROM, SPI_EEPROM)
+  #define USE_SHARED_EEPROM 1
+#endif

Marlin/src/HAL/SAMD21/inc/SanityCheck.h

@@ -0,0 +1,50 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Test SAMD21 specific configuration values for errors at compile-time.
+ */
+
+#if SERVO_TC == MF_TIMER_RTC
+  #error "Servos can't use RTC timer"
+#endif
+
+#if ENABLED(EMERGENCY_PARSER)
+  #error "EMERGENCY_PARSER is not yet implemented for SAMD21. Disable EMERGENCY_PARSER to continue."
+#endif
+
+#if ENABLED(SDIO_SUPPORT)
+  #error "SDIO_SUPPORT is not supported on SAMD21."
+#endif
+
+#if ENABLED(FAST_PWM_FAN)
+  #error "Features requiring Hardware PWM (FAST_PWM_FAN) are not yet supported on SAMD21."
+#endif
+
+#if ENABLED(POSTMORTEM_DEBUGGING)
+  #error "POSTMORTEM_DEBUGGING is not yet supported on SAMD21."
+#endif

Marlin/src/HAL/SAMD21/pinsDebug.h

@@ -0,0 +1,160 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+#define NUMBER_PINS_TOTAL PINS_COUNT
+
+#define digitalRead_mod(p) extDigitalRead(p)
+#define PRINT_PORT(p) do{ SERIAL_ECHOPGM("  Port: "); sprintf_P(buffer, PSTR("%c%02ld"), 'A' + g_APinDescription[p].ulPort, g_APinDescription[p].ulPin); SERIAL_ECHO(buffer); }while (0)
+#define PRINT_ARRAY_NAME(x) do{ sprintf_P(buffer, PSTR("%-" STRINGIFY(MAX_NAME_LENGTH) "s"), pin_array[x].name); SERIAL_ECHO(buffer); }while(0)
+#define PRINT_PIN(p) do{ sprintf_P(buffer, PSTR("%3d "), p); SERIAL_ECHO(buffer); }while(0)
+#define PRINT_PIN_ANALOG(p) do{ sprintf_P(buffer, PSTR(" (A%2d)  "), DIGITAL_PIN_TO_ANALOG_PIN(pin)); SERIAL_ECHO(buffer); }while(0)
+#define GET_ARRAY_PIN(p) pin_array[p].pin
+#define GET_ARRAY_IS_DIGITAL(p) pin_array[p].is_digital
+#define VALID_PIN(pin) (pin >= 0 && pin < (int8_t)NUMBER_PINS_TOTAL)
+#define DIGITAL_PIN_TO_ANALOG_PIN(p) digitalPinToAnalogInput(p)
+#define IS_ANALOG(P) (DIGITAL_PIN_TO_ANALOG_PIN(P)!=-1)
+#define pwm_status(pin) digitalPinHasPWM(pin)
+#define MULTI_NAME_PAD 27 // space needed to be pretty if not first name assigned to a pin
+
+// pins that will cause hang/reset/disconnect in M43 Toggle and Watch utilities
+// uses pin index
+#define M43_NEVER_TOUCH(Q) ((Q) >= 75)
+
+bool GET_PINMODE(int8_t pin) {  // 1: output, 0: input
+  const EPortType samdport = g_APinDescription[pin].ulPort;
+  const uint32_t samdpin = g_APinDescription[pin].ulPin;
+  return PORT->Group[samdport].DIR.reg & MASK(samdpin) || (PORT->Group[samdport].PINCFG[samdpin].reg & (PORT_PINCFG_INEN | PORT_PINCFG_PULLEN)) == PORT_PINCFG_PULLEN;
+}
+
+void pwm_details(int32_t pin) {
+  if (pwm_status(pin)) {
+    //uint32_t chan = g_APinDescription[pin].ulPWMChannel TODO when fast pwm is operative;
+    //SERIAL_ECHOPGM("PWM = ", duty);
+  }
+}
+
+/**
+ * SAMD21 Board pin|  PORT  | Label
+ * ----------------+--------+-------
+ *   0             |  PB25  | "RX0"
+ *   1             |  PB24  | "TX0"
+ *   2             |  PC18  |
+ *   3             |  PC19  |
+ *   4             |  PC20  |
+ *   5             |  PC21  |
+ *   6             |  PD20  |
+ *   7             |  PD21  |
+ *   8             |  PB18  |
+ *   9             |  PB2   |
+ *  10             |  PB22  |
+ *  11             |  PB23  |
+ *  12             |  PB0   | "A16"
+ *  13             |  PB1   | LED AMBER "L" / "A17"
+ *  14             |  PB16  | "TX3"
+ *  15             |  PB17  | "RX3"
+ *  16             |  PC22  | "TX2"
+ *  17             |  PC23  | "RX2"
+ *  18             |  PB12  | "TX1" / "A18"
+ *  19             |  PB13  | "RX1"
+ *  20             |  PB20  | "SDA"
+ *  21             |  PB21  | "SCL"
+ *  22             |  PD12  |
+ *  23             |  PA15  |
+ *  24             |  PC17  |
+ *  25             |  PC16  |
+ *  26             |  PA12  |
+ *  27             |  PA13  |
+ *  28             |  PA14  |
+ *  29             |  PB19  |
+ *  30             |  PA23  |
+ *  31             |  PA22  |
+ *  32             |  PA21  |
+ *  33             |  PA20  |
+ *  34             |  PA19  |
+ *  35             |  PA18  |
+ *  36             |  PA17  |
+ *  37             |  PA16  |
+ *  38             |  PB15  |
+ *  39             |  PB14  |
+ *  40             |  PC13  |
+ *  41             |  PC12  |
+ *  42             |  PC15  |
+ *  43             |  PC14  |
+ *  44             |  PC11  |
+ *  45             |  PC10  |
+ *  46             |  PC6   |
+ *  47             |  PC7   |
+ *  48             |  PC4   |
+ *  49             |  PC5   |
+ *  50             |  PD11  |
+ *  51             |  PD8   |
+ *  52             |  PD9   |
+ *  53             |  PD10  |
+ *  54             |  PB5   | "A8"
+ *  55             |  PB6   | "A9"
+ *  56             |  PB7   | "A10"
+ *  57             |  PB8   | "A11"
+ *  58             |  PB9   | "A12"
+ *  69             |  PA4   | "A13"
+ *  60             |  PA6   | "A14"
+ *  61             |  PA7   | "A15"
+ *  62             |  PB17  |
+ *  63             |  PB20  |
+ *  64             |  PD11  |
+ *  65             |  PD8   |
+ *  66             |  PD9   |
+ *  67             |  PA2   | "A0" / "DAC0"
+ *  68             |  PA5   | "A1" / "DAC1"
+ *  69             |  PB3   | "A2"
+ *  70             |  PC0   | "A3"
+ *  71             |  PC1   | "A4"
+ *  72             |  PC2   | "A5"
+ *  73             |  PC3   | "A6"
+ *  74             |  PB4   | "A7"
+ *  75             |  PC31  | LED GREEN "RX"
+ *  76             |  PC30  | LED GREEN "TX"
+ *  77             |  PA27  | USB: Host enable
+ *  78             |  PA24  | USB: D-
+ *  79             |  PA25  | USB: D+
+ *  80             |  PB29  | SD: MISO
+ *  81             |  PB27  | SD: SCK
+ *  82             |  PB26  | SD: MOSI
+ *  83             |  PB28  | SD: CS
+ *  84             |  PA3   | AREF
+ *  85             |  PA2   | DAC0 (Duplicate)
+ *  86             |  PA5   | DAC1 (Duplicate)
+ *  87             |  PB1   | LED AMBER "L" (Duplicate)
+ *  88             |  PC24  | NeoPixel
+ *  89             |  PB10  | QSPI: SCK
+ *  90             |  PB11  | QSPI: CS
+ *  91             |  PA8   | QSPI: IO0
+ *  92             |  PA9   | QSPI: IO1
+ *  93             |  PA10  | QSPI: IO2
+ *  94             |  PA11  | QSPI: IO3
+ *  95             |  PB31  | SD: DETECT
+ */

Marlin/src/HAL/SAMD21/spi_pins.h

@@ -0,0 +1,54 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * SAMD21 Default SPI Pins
+ *
+ *         SS    SCK   MISO   MOSI
+ *       +-------------------------+
+ *  SPI  | 53    52     50     51  |
+ *  SPI1 | 83    81     80     82  |
+ *       +-------------------------+
+ * Any pin can be used for Chip Select (SD_SS_PIN)
+ */
+#ifndef SD_SCK_PIN
+  #define SD_SCK_PIN    38
+#endif
+#ifndef SD_MISO_PIN
+  #define SD_MISO_PIN   36
+#endif
+#ifndef SD_MOSI_PIN
+  #define SD_MOSI_PIN   37
+#endif
+#ifndef SDSS
+  #define SDSS          18
+#endif
+
+#ifndef SD_SS_PIN
+  #define SD_SS_PIN     SDSS
+#endif

Marlin/src/HAL/SAMD21/timers.cpp

@@ -0,0 +1,217 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#ifdef __SAMD21__
+
+// --------------------------------------------------------------------------
+// Includes
+// --------------------------------------------------------------------------
+
+#include "../../inc/MarlinConfig.h"
+#include "ServoTimers.h" // for SERVO_TC
+
+// --------------------------------------------------------------------------
+// Local defines
+// --------------------------------------------------------------------------
+
+#define NUM_HARDWARE_TIMERS 9
+
+// --------------------------------------------------------------------------
+// Private Variables
+// --------------------------------------------------------------------------
+
+const tTimerConfig timer_config[NUM_HARDWARE_TIMERS] = {
+  { {.pTcc=TCC0}, TimerType::tcc,  TCC0_IRQn, TC_PRIORITY(0) },  // 0 - stepper (assigned priority 2)
+  { {.pTcc=TCC1}, TimerType::tcc,  TCC1_IRQn, TC_PRIORITY(1) },  // 1 - stepper (needed by 32 bit timers)
+  { {.pTcc=TCC2}, TimerType::tcc,  TCC2_IRQn, 5              },  // 2 - tone (reserved by framework and fixed assigned priority 5)
+  { {.pTc=TC3},   TimerType::tc,   TC3_IRQn,  TC_PRIORITY(3) },  // 3 - servo (assigned priority 1)
+  { {.pTc=TC4},   TimerType::tc,   TC4_IRQn,  TC_PRIORITY(4) },  // 4 - software serial (no interrupts used)
+  { {.pTc=TC5},   TimerType::tc,   TC5_IRQn,  TC_PRIORITY(5) },
+  { {.pTc=TC6},   TimerType::tc,   TC6_IRQn,  TC_PRIORITY(6) },
+  { {.pTc=TC7},   TimerType::tc,   TC7_IRQn,  TC_PRIORITY(7) },
+  { {.pRtc=RTC},  TimerType::rtc,   RTC_IRQn, TC_PRIORITY(8) }   // 8 - temperature (assigned priority 6)
+};
+
+// --------------------------------------------------------------------------
+// Private functions
+// --------------------------------------------------------------------------
+
+FORCE_INLINE void Disable_Irq(IRQn_Type irq) {
+  NVIC_DisableIRQ(irq);
+
+  // We NEED memory barriers to ensure Interrupts are actually disabled!
+  // ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
+  __DSB();
+  __ISB();
+}
+
+static bool tcIsSyncing(Tc * tc) {
+  return tc->COUNT32.STATUS.reg & TC_STATUS_SYNCBUSY;
+}
+
+static void tcReset( Tc * tc) {
+  tc->COUNT32.CTRLA.reg = TC_CTRLA_SWRST;
+  while (tcIsSyncing(tc)) {}
+  while (tc->COUNT32.CTRLA.bit.SWRST) {}
+}
+
+// --------------------------------------------------------------------------
+// Public functions
+// --------------------------------------------------------------------------
+
+void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
+  IRQn_Type irq = timer_config[timer_num].IRQ_Id;
+
+  // Disable interrupt, just in case it was already enabled
+  NVIC_DisableIRQ(irq);
+  NVIC_ClearPendingIRQ(irq);
+
+  if (timer_num == MF_TIMER_RTC) {
+
+    // https://github.com/arduino-libraries/RTCZero
+    Rtc * const rtc = timer_config[timer_num].pRtc;
+    PM->APBAMASK.reg |= PM_APBAMASK_RTC;
+
+    GCLK->CLKCTRL.reg = (uint32_t)((GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK4 | (RTC_GCLK_ID << GCLK_CLKCTRL_ID_Pos)));
+    while (GCLK->STATUS.bit.SYNCBUSY) {}
+
+    GCLK->GENCTRL.reg = (GCLK_GENCTRL_GENEN | GCLK_GENCTRL_SRC_OSCULP32K | GCLK_GENCTRL_ID(4) | GCLK_GENCTRL_DIVSEL );
+    while (GCLK->STATUS.reg & GCLK_STATUS_SYNCBUSY) {}
+
+    GCLK->GENDIV.reg = GCLK_GENDIV_ID(4);
+    GCLK->GENDIV.bit.DIV=4;
+    while (GCLK->STATUS.reg & GCLK_STATUS_SYNCBUSY) {}
+
+    // Disable timer interrupt
+    rtc->MODE0.INTENCLR.reg = RTC_MODE0_INTENCLR_CMP0;
+    SYNC(rtc->MODE0.STATUS.bit.SYNCBUSY);
+
+    while(rtc->MODE0.STATUS.bit.SYNCBUSY) {}
+
+    // Stop timer, just in case, to be able to reconfigure it
+    rtc->MODE0.CTRL.reg =
+      RTC_MODE0_CTRL_MODE_COUNT32 |           // Mode 0 = 32-bits counter
+      RTC_MODE0_CTRL_PRESCALER_DIV1024;       // Divisor = 1024
+
+    while(rtc->MODE0.STATUS.bit.SYNCBUSY) {}
+
+    // Mode, reset counter on match
+    rtc->MODE0.CTRL.reg = RTC_MODE0_CTRL_MODE_COUNT32 | RTC_MODE0_CTRL_MATCHCLR;
+
+    // Set compare value
+    rtc->MODE0.COMP[0].reg = (32768 + frequency / 2) / frequency;
+    SYNC(rtc->MODE0.STATUS.bit.SYNCBUSY);
+
+    // Enable interrupt on compare
+    rtc->MODE0.INTFLAG.reg = RTC_MODE0_INTFLAG_CMP0;    // reset pending interrupt
+    rtc->MODE0.INTENSET.reg = RTC_MODE0_INTENSET_CMP0;  // enable compare 0 interrupt
+
+    // And start timer
+    rtc->MODE0.CTRL.bit.ENABLE = true;
+    SYNC(rtc->MODE0.STATUS.bit.SYNCBUSY);
+
+  }
+  else if (timer_config[timer_num].type==TimerType::tcc) {
+
+    Tcc * const tc = timer_config[timer_num].pTcc;
+
+    PM->APBCMASK.reg |= PM_APBCMASK_TCC0;
+     GCLK->CLKCTRL.reg =(GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_ID(TCC0_GCLK_ID));
+    SYNC (GCLK->STATUS.bit.SYNCBUSY);
+
+    tc->CTRLA.reg = TCC_CTRLA_SWRST;
+    SYNC (tc->SYNCBUSY.reg & TCC_SYNCBUSY_SWRST) {}
+
+    SYNC (tc->CTRLA.bit.SWRST);
+
+    tc->CTRLA.reg &= ~(TCC_CTRLA_ENABLE);       // disable TC module
+
+    tc->CTRLA.reg |= TCC_WAVE_WAVEGEN_MFRQ;
+    tc->CTRLA.reg |= TCC_CTRLA_PRESCALER_DIV2;
+    tc->CC[0].reg = (HAL_TIMER_RATE) / frequency;
+    tc->INTENSET.reg = TCC_INTFLAG_MC0;
+    tc->CTRLA.reg |= TCC_CTRLA_ENABLE;
+    tc->INTFLAG.reg = 0xFF;
+    SYNC ( tc->STATUS.reg & TC_STATUS_SYNCBUSY);
+
+  }
+  else {
+    Tc * const tc = timer_config[timer_num].pTc;
+
+    // Disable timer interrupt
+    tc->COUNT32.INTENCLR.reg = TC_INTENCLR_OVF; // disable overflow interrupt
+
+    // TCn clock setup
+    GCLK->CLKCTRL.reg = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0  | GCLK_CLKCTRL_ID(GCM_TC4_TC5)) ;
+    SYNC (GCLK->STATUS.bit.SYNCBUSY);
+
+    tcReset(tc); // reset TC
+
+    // Set Timer counter 5 Mode to 16 bits, it will become a 16bit counter ('mode1' in the datasheet)
+    tc->COUNT32.CTRLA.reg |= TC_CTRLA_MODE_COUNT32;
+    // Set TC waveform generation mode to 'match frequency'
+    tc->COUNT32.CTRLA.reg |= TC_CTRLA_WAVEGEN_MFRQ;
+    //set prescaler
+    //the clock normally counts at the GCLK_TC frequency, but we can set it to divide that frequency to slow it down
+    //you can use different prescaler divisons here like TC_CTRLA_PRESCALER_DIV1 to get a different range
+    tc->COUNT32.CTRLA.reg |= TC_CTRLA_PRESCALER_DIV1 | TC_CTRLA_ENABLE; //it will divide GCLK_TC frequency by 1024
+    //set the compare-capture register.
+    //The counter will count up to this value (it's a 16bit counter so we use uint16_t)
+    //this is how we fine-tune the frequency, make it count to a lower or higher value
+    //system clock should be 1MHz (8MHz/8) at Reset by default
+    tc->COUNT32.CC[0].reg = (uint16_t) (HAL_TIMER_RATE / frequency);
+    while (tcIsSyncing(tc)) {}
+
+    // Enable the TC interrupt request
+    tc->COUNT32.INTENSET.bit.MC0 = 1;
+    while (tcIsSyncing(tc)) {}
+  }
+
+  NVIC_SetPriority(irq, timer_config[timer_num].priority);
+  NVIC_EnableIRQ(irq);
+}
+
+void HAL_timer_enable_interrupt(const uint8_t timer_num) {
+  const IRQn_Type irq = timer_config[timer_num].IRQ_Id;
+  NVIC_EnableIRQ(irq);
+}
+
+void HAL_timer_disable_interrupt(const uint8_t timer_num) {
+  const IRQn_Type irq = timer_config[timer_num].IRQ_Id;
+  Disable_Irq(irq);
+}
+
+// missing from CMSIS: Check if interrupt is enabled or not
+static bool NVIC_GetEnabledIRQ(IRQn_Type IRQn) {
+  return TEST(NVIC->ISER[uint32_t(IRQn) >> 5], uint32_t(IRQn) & 0x1F);
+}
+
+bool HAL_timer_interrupt_enabled(const uint8_t timer_num) {
+  const IRQn_Type irq = timer_config[timer_num].IRQ_Id;
+  return NVIC_GetEnabledIRQ(irq);
+}
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/timers.h

@@ -0,0 +1,160 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+#include <stdint.h>
+
+// --------------------------------------------------------------------------
+// Defines
+// --------------------------------------------------------------------------
+
+typedef uint32_t hal_timer_t;
+#define HAL_TIMER_TYPE_MAX 0xFFFFFFFF
+
+#define HAL_TIMER_RATE      F_CPU   // frequency of timers peripherals
+
+#define MF_TIMER_RTC            8   // This is not a TC but a RTC
+
+#ifndef MF_TIMER_STEP
+  #define MF_TIMER_STEP         4   // Timer Index for Stepper
+#endif
+#ifndef MF_TIMER_PULSE
+  #define MF_TIMER_PULSE        MF_TIMER_STEP
+#endif
+#ifndef MF_TIMER_TEMP
+  #define MF_TIMER_TEMP         MF_TIMER_RTC // Timer Index for Temperature
+#endif
+
+#define TEMP_TIMER_FREQUENCY   1000 // temperature interrupt frequency
+
+#define STEPPER_TIMER_RATE          HAL_TIMER_RATE   // frequency of stepper timer (HAL_TIMER_RATE / STEPPER_TIMER_PRESCALE)
+#define STEPPER_TIMER_TICKS_PER_US  (STEPPER_TIMER_RATE / 1000000) // stepper timer ticks per µs
+#define STEPPER_TIMER_PRESCALE      (CYCLES_PER_MICROSECOND / STEPPER_TIMER_TICKS_PER_US)
+
+#define PULSE_TIMER_RATE          STEPPER_TIMER_RATE
+#define PULSE_TIMER_PRESCALE      STEPPER_TIMER_PRESCALE
+#define PULSE_TIMER_TICKS_PER_US  STEPPER_TIMER_TICKS_PER_US
+
+#define ENABLE_STEPPER_DRIVER_INTERRUPT()   HAL_timer_enable_interrupt(MF_TIMER_STEP)
+#define DISABLE_STEPPER_DRIVER_INTERRUPT()  HAL_timer_disable_interrupt(MF_TIMER_STEP)
+#define STEPPER_ISR_ENABLED()               HAL_timer_interrupt_enabled(MF_TIMER_STEP)
+
+#define ENABLE_TEMPERATURE_INTERRUPT()  HAL_timer_enable_interrupt(MF_TIMER_TEMP)
+#define DISABLE_TEMPERATURE_INTERRUPT() HAL_timer_disable_interrupt(MF_TIMER_TEMP)
+
+#define TC_PRIORITY(t) (  t == SERVO_TC ? 1                              \
+                       : (t == MF_TIMER_STEP || t == MF_TIMER_PULSE) ? 2 \
+                       : (t == MF_TIMER_TEMP) ? 6 : 7 )
+
+#define _TC_HANDLER(t)          void TC##t##_Handler()
+#define TC_HANDLER(t)           _TC_HANDLER(t)
+#ifndef HAL_STEP_TIMER_ISR
+  #define HAL_STEP_TIMER_ISR()  TC_HANDLER(MF_TIMER_STEP)
+#endif
+#if MF_TIMER_STEP != MF_TIMER_PULSE
+  #define HAL_PULSE_TIMER_ISR() TC_HANDLER(MF_TIMER_PULSE)
+#endif
+#if MF_TIMER_TEMP == MF_TIMER_RTC
+  #define HAL_TEMP_TIMER_ISR()  void RTC_Handler()
+#else
+  #define HAL_TEMP_TIMER_ISR()  TC_HANDLER(MF_TIMER_TEMP)
+#endif
+
+// --------------------------------------------------------------------------
+// Types
+// --------------------------------------------------------------------------
+typedef enum  { tcc, tc, rtc } TimerType;
+
+typedef struct {
+  union {
+    Tc  *pTc;
+    Tcc *pTcc;
+    Rtc *pRtc;
+  };
+  TimerType type;
+  IRQn_Type   IRQ_Id;
+  uint8_t     priority;
+} tTimerConfig;
+
+// --------------------------------------------------------------------------
+// Public Variables
+// --------------------------------------------------------------------------
+
+extern const tTimerConfig timer_config[];
+
+// --------------------------------------------------------------------------
+// Public functions
+// --------------------------------------------------------------------------
+
+void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency);
+
+FORCE_INLINE static void HAL_timer_set_compare(const uint8_t timer_num, const hal_timer_t compare) {
+  // Should never be called with timer MF_TIMER_RTC
+  Tc * const tc = timer_config[timer_num].pTc;
+  tc->COUNT32.CC[0].reg = compare;
+}
+
+FORCE_INLINE static hal_timer_t HAL_timer_get_compare(const uint8_t timer_num) {
+  // Should never be called with timer MF_TIMER_RTC
+  Tc * const tc = timer_config[timer_num].pTc;
+  return (hal_timer_t)tc->COUNT32.CC[0].reg;
+}
+
+FORCE_INLINE static hal_timer_t HAL_timer_get_count(const uint8_t timer_num) {
+  // Should never be called with timer MF_TIMER_RTC
+  Tc * const tc = timer_config[timer_num].pTc;
+  tc->COUNT32.READREQ.reg = TC_READREQ_RREQ;
+  // Request a read synchronization
+  SYNC (tc->COUNT32.STATUS.bit.SYNCBUSY);
+  //SYNC(tc->COUNT32.STATUS.bit.SYNCBUSY );
+  return tc->COUNT32.COUNT.reg;
+}
+
+void HAL_timer_enable_interrupt(const uint8_t timer_num);
+void HAL_timer_disable_interrupt(const uint8_t timer_num);
+bool HAL_timer_interrupt_enabled(const uint8_t timer_num);
+
+FORCE_INLINE static void HAL_timer_isr_prologue(const uint8_t timer_num) {
+  if (timer_num == MF_TIMER_RTC) {
+    Rtc * const rtc = timer_config[timer_num].pRtc;
+    // Clear interrupt flag
+    rtc->MODE0.INTFLAG.reg = RTC_MODE0_INTFLAG_CMP0| RTC_MODE0_INTFLAG_OVF;
+
+  }
+  else if (timer_config[timer_num].type == TimerType::tcc){
+    Tcc * const tc = timer_config[timer_num].pTcc;
+    // Clear interrupt flag
+    tc->INTFLAG.reg = TCC_INTFLAG_OVF;
+  }
+  else {
+    Tc * const tc = timer_config[timer_num].pTc;
+    // Clear interrupt flag
+    tc->COUNT32.INTFLAG.bit.MC0 = 1;
+  }
+}
+
+#define HAL_timer_isr_epilogue(timer_num)

Marlin/src/HAL/SAMD21/u8g/LCD_I2C_routines.cpp

@@ -0,0 +1,32 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+// adapted from  I2C/master/master.c example
+//   https://www-users.cs.york.ac.uk/~pcc/MCP/HAPR-Course-web/CMSIS/examples/html/master_8c_source.html
+
+#ifdef __SAMD21__
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/u8g/LCD_I2C_routines.h

@@ -0,0 +1,27 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once

Marlin/src/HAL/SAMD21/u8g/LCD_defines.h

@@ -0,0 +1,41 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once
+
+/**
+ * SAMD21 LCD-specific defines
+ */
+
+// The following are optional depending on the platform.
+
+// definitions of HAL specific com and device drivers.
+uint8_t u8g_com_samd21_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
+uint8_t u8g_com_samd21_st7920_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
+
+// connect U8g com generic com names to the desired driver
+#define U8G_COM_HW_SPI u8g_com_samd21_st7920_hw_spi_fn  // use SAMD21 specific hardware SPI routine
+#define U8G_COM_ST7920_HW_SPI u8g_com_samd21_st7920_hw_spi_fn

Marlin/src/HAL/SAMD21/u8g/LCD_pin_routines.c

@@ -0,0 +1,42 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Low level pin manipulation routines - used by all the drivers.
+ *
+ * These are based on the SAMD51 pinMode, digitalRead & digitalWrite routines.
+ *
+ * Couldn't just call exact copies because the overhead killed the LCD update speed
+ * With an intermediate level the softspi was running in the 10-20kHz range which
+ * resulted in using about about 25% of the CPU's time.
+ */
+
+#ifdef __SAMD21__
+
+#include <Arduino.h>
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD21/u8g/LCD_pin_routines.h

@@ -0,0 +1,42 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+#pragma once
+
+/**
+ * Low level pin manipulation routines - used by all the drivers.
+ *
+ * These are based on the SAMD51 pinMode, digitalRead & digitalWrite routines.
+ *
+ * Couldn't just call exact copies because the overhead killed the LCD update speed
+ * With an intermediate level the softspi was running in the 10-20kHz range which
+ * resulted in using about about 25% of the CPU's time.
+ */
+
+void u8g_SetPinOutput(uint8_t internal_pin_number);
+void u8g_SetPinInput(uint8_t internal_pin_number);
+void u8g_SetPinLevel(uint8_t  pin, uint8_t  pin_status);
+uint8_t u8g_GetPinLevel(uint8_t pin);

Marlin/src/HAL/SAMD21/u8g/u8g_com_HAL_samd21_shared_hw_spi.cpp

@@ -0,0 +1,154 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2022 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * SAMD21 HAL developed by Bart Meijer (brupje)
+ * Based on SAMD51 HAL by Giuliano Zaro (AKA GMagician)
+ */
+
+/**
+ * Based on u8g_com_msp430_hw_spi.c
+ *
+ * Universal 8bit Graphics Library
+ *
+ * Copyright (c) 2012, olikraus@gmail.com
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this list
+ * of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice, this
+ * list of conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef __SAMD21__
+
+#include <U8glib-HAL.h>
+#include "SPI.h"
+
+#include "../../shared/HAL_SPI.h"
+
+#ifndef LCD_SPI_SPEED
+  #define LCD_SPI_SPEED SPI_QUARTER_SPEED
+#endif
+
+void u8g_SetPIOutput(u8g_t *u8g, uint8_t pin_index) {
+  if (u8g->pin_list[pin_index]!= U8G_PIN_NONE)
+  pinMode(u8g->pin_list[pin_index],OUTPUT);
+}
+
+void u8g_SetPILevel(u8g_t *u8g, uint8_t pin_index, uint8_t level) {
+  if (u8g->pin_list[pin_index]!= U8G_PIN_NONE)
+  digitalWrite(u8g->pin_list[pin_index],level);
+}
+
+uint8_t u8g_com_samd21_st7920_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
+
+  static SPISettings lcdSPIConfig;
+
+  switch (msg) {
+    case U8G_COM_MSG_STOP:
+      break;
+
+    case U8G_COM_MSG_INIT:
+      u8g_SetPIOutput(u8g, U8G_PI_CS);
+      u8g_SetPIOutput(u8g, U8G_PI_A0);
+      u8g_SetPIOutput(u8g, U8G_PI_RESET);
+
+      u8g_SetPILevel(u8g, U8G_PI_CS, LOW);
+
+      spiBegin();
+      lcdSPIConfig = SPISettings(900000, MSBFIRST, SPI_MODE0);
+      u8g->pin_list[U8G_PI_A0_STATE] = 0;
+      break;
+
+    case U8G_COM_MSG_ADDRESS:             // define cmd (arg_val = 0) or data mode (arg_val = 1)
+      u8g_SetPILevel(u8g, U8G_PI_A0, arg_val);
+      u8g->pin_list[U8G_PI_A0_STATE] = arg_val;
+      break;
+
+    case U8G_COM_MSG_CHIP_SELECT:         // arg_val == 1 means chip selected, but ST7920 is active high, so needs inverting
+      u8g_SetPILevel(u8g, U8G_PI_CS, arg_val ? HIGH : LOW);
+      break;
+
+    case U8G_COM_MSG_RESET:
+      u8g_SetPILevel(u8g, U8G_PI_RESET, arg_val);
+      break;
+
+    case U8G_COM_MSG_WRITE_BYTE:
+      SPI.beginTransaction(lcdSPIConfig);
+
+      if (u8g->pin_list[U8G_PI_A0_STATE] == 0) { // command
+        SPI.transfer(0x0f8); u8g->pin_list[U8G_PI_A0_STATE] = 2;
+      }
+      else if (u8g->pin_list[U8G_PI_A0_STATE] == 1) { // data
+        SPI.transfer(0x0fa); u8g->pin_list[U8G_PI_A0_STATE] = 2;
+      }
+
+      SPI.transfer(arg_val & 0x0f0);
+      SPI.transfer(arg_val << 4);
+      SPI.endTransaction();
+      break;
+
+    case U8G_COM_MSG_WRITE_SEQ:
+      SPI.beginTransaction(lcdSPIConfig);
+
+      if (u8g->pin_list[U8G_PI_A0_STATE] == 0 ) { // command
+        SPI.transfer(0x0f8); u8g->pin_list[U8G_PI_A0_STATE] = 2;
+      }
+      else if (u8g->pin_list[U8G_PI_A0_STATE] == 1) { // data
+        SPI.transfer(0x0fa); u8g->pin_list[U8G_PI_A0_STATE] = 2;
+      }
+
+      uint8_t *ptr = (uint8_t*)arg_ptr;
+      while (arg_val > 0) {
+        SPI.transfer((*ptr) & 0x0f0);
+        SPI.transfer((*ptr) << 4);
+        ptr++;
+        arg_val--;
+      }
+
+      SPI.endTransaction();
+      break;
+  }
+  return 1;
+}
+
+#endif // __SAMD21__

Marlin/src/HAL/SAMD51/HAL.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef __SAMD51__
 
 #include "../../inc/MarlinConfig.h"

Marlin/src/HAL/SAMD51/HAL.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #define CPU_32_BIT
 
 #include "../shared/Marduino.h"

Marlin/src/HAL/SAMD51/HAL_SPI.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -19,6 +20,10 @@
  *
  */
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 /**
  * Hardware and software SPI implementations are included in this file.
  *

Marlin/src/HAL/SAMD51/MarlinSerial_AGCM4.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef ADAFRUIT_GRAND_CENTRAL_M4
 
 /**

Marlin/src/HAL/SAMD51/MarlinSerial_AGCM4.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #include "../../core/serial_hook.h"
 
 typedef Serial1Class<Uart> UartT;

Marlin/src/HAL/SAMD51/SAMD51.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #define SYNC(sc)    while (sc) {  \
                       asm("");    \
                     }

Marlin/src/HAL/SAMD51/Servo.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -19,6 +20,10 @@
  *
  */
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 /**
  * This comes from Arduino library which at the moment is buggy and uncompilable
  */

Marlin/src/HAL/SAMD51/ServoTimers.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #define _useTimer1
 #define _useTimer2
 

Marlin/src/HAL/SAMD51/eeprom_flash.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef __SAMD51__
 
 #include "../../inc/MarlinConfig.h"

Marlin/src/HAL/SAMD51/eeprom_qspi.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef __SAMD51__
 
 #include "../../inc/MarlinConfig.h"

Marlin/src/HAL/SAMD51/eeprom_wired.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef __SAMD51__
 
 #include "../../inc/MarlinConfig.h"

Marlin/src/HAL/SAMD51/endstop_interrupts.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 /**
  * Endstop interrupts for ATMEL SAMD51 based targets.
  *

Marlin/src/HAL/SAMD51/fastio.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 /**
  * Fast IO functions for SAMD51
  */

Marlin/src/HAL/SAMD51/inc/SanityCheck.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+#pragma once
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 
 /**
  * Test SAMD51 specific configuration values for errors at compile-time.

Marlin/src/HAL/SAMD51/pinsDebug.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #define NUMBER_PINS_TOTAL PINS_COUNT
 
 #define digitalRead_mod(p) extDigitalRead(p)

Marlin/src/HAL/SAMD51/spi_pins.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #ifdef ADAFRUIT_GRAND_CENTRAL_M4
 
  /*

Marlin/src/HAL/SAMD51/timers.cpp

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +19,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
+
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
 #ifdef __SAMD51__
 
 // --------------------------------------------------------------------------

Marlin/src/HAL/SAMD51/timers.h

@@ -1,8 +1,9 @@
 /**
  * Marlin 3D Printer Firmware
- *
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
- * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,6 +21,10 @@
  */
 #pragma once
 
+/**
+ * SAMD51 HAL developed by Giuliano Zaro (AKA GMagician)
+ */
+
 #include <stdint.h>
 
 // --------------------------------------------------------------------------

Marlin/src/HAL/STM32/eeprom_flash.cpp

@@ -221,7 +221,7 @@ bool PersistentStore::access_finish() {
 
       return success;
 
-    #else !FLASH_EEPROM_LEVELING
+    #else // !FLASH_EEPROM_LEVELING
 
       // The following was written for the STM32F4 but may work with other MCUs as well.
       // Most STM32F4 flash does not allow reading from flash during erase operations.

Marlin/src/HAL/STM32/eeprom_sdcard.cpp

@@ -48,7 +48,7 @@ static char _ALIGN(4) HAL_eeprom_data[MARLIN_EEPROM_SIZE];
 bool PersistentStore::access_start() {
   if (!card.isMounted()) return false;
 
-  SdFile file, root = card.getroot();
+  MediaFile file, root = card.getroot();
   if (!file.open(&root, EEPROM_FILENAME, O_RDONLY))
     return true;
 
@@ -63,7 +63,7 @@ bool PersistentStore::access_start() {
 bool PersistentStore::access_finish() {
   if (!card.isMounted()) return false;
 
-  SdFile file, root = card.getroot();
+  MediaFile file, root = card.getroot();
   int bytes_written = 0;
   if (file.open(&root, EEPROM_FILENAME, O_CREAT | O_WRITE | O_TRUNC)) {
     bytes_written = file.write(HAL_eeprom_data, MARLIN_EEPROM_SIZE);

Marlin/src/HAL/STM32/inc/SanityCheck.h

@@ -50,3 +50,62 @@
 #if ANY(TFT_COLOR_UI, TFT_LVGL_UI, TFT_CLASSIC_UI) && NOT_TARGET(STM32H7xx, STM32F4xx, STM32F1xx)
   #error "TFT_COLOR_UI, TFT_LVGL_UI and TFT_CLASSIC_UI are currently only supported on STM32H7, STM32F4 and STM32F1 hardware."
 #endif
+
+/**
+ * Check for common serial pin conflicts
+ */
+#define _CHECK_SERIAL_PIN(N) (( \
+    BTN_EN1 == N || DOGLCD_CS == N || HEATER_BED_PIN == N || FAN_PIN == N || \
+    SDIO_D2_PIN == N || SDIO_D3_PIN == N || SDIO_CK_PIN == N || SDIO_CMD_PIN == N \
+  ))
+#define CHECK_SERIAL_PIN(T,N) defined(UART##N##_##T##_PIN) && _CHECK_SERIAL_PIN(UART##N##_##T##_PIN)
+#if SERIAL_IN_USE(1)
+  #if CHECK_SERIAL_PIN(TX,1)
+    #error "Serial Port 1 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,1)
+    #error "Serial Port 1 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(2)
+  #if CHECK_SERIAL_PIN(TX,2)
+    #error "Serial Port 2 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,2)
+    #error "Serial Port 2 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(3)
+  #if CHECK_SERIAL_PIN(TX,3)
+    #error "Serial Port 3 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,3)
+    #error "Serial Port 3 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(4)
+  #if CHECK_SERIAL_PIN(TX,4)
+    #error "Serial Port 4 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,4)
+    #error "Serial Port 4 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(5)
+  #if CHECK_SERIAL_PIN(TX,5)
+    #error "Serial Port 5 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,5)
+    #error "Serial Port 5 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#if SERIAL_IN_USE(6)
+  #if CHECK_SERIAL_PIN(TX,6)
+    #error "Serial Port 6 TX IO pins conflict with another pin on the board."
+  #endif
+  #if CHECK_SERIAL_PIN(RX,6)
+    #error "Serial Port 6 RX IO pins conflict with another pin on the board."
+  #endif
+#endif
+#undef CHECK_SERIAL_PIN
+#undef _CHECK_SERIAL_PIN

Marlin/src/HAL/STM32/sdio.cpp

@@ -286,6 +286,9 @@ void HAL_SD_MspInit(SD_HandleTypeDef *hsd) {
 
     go_to_transfer_speed();
 
+    hsd.Init.ClockPowerSave = SDIO_CLOCK_POWER_SAVE_ENABLE;
+    hsd.Init.ClockDiv = 8;
+
     #if PINS_EXIST(SDIO_D1, SDIO_D2, SDIO_D3) // go to 4 bit wide mode if pins are defined
       retry_Cnt = retryCnt;
       for (;;) {
@@ -433,7 +436,10 @@ bool SDIO_WriteBlock(uint32_t block, const uint8_t *src) {
   #else
 
     uint8_t retries = SDIO_READ_RETRIES;
-    while (retries--) if (SDIO_ReadWriteBlock_DMA(block, src, nullptr)) return true;
+    while (retries--) {
+      if (SDIO_ReadWriteBlock_DMA(block, src, nullptr)) return true;
+      delay(10);
+    }
     return false;
 
   #endif

Marlin/src/HAL/STM32/tft/gt911.cpp

@@ -150,9 +150,9 @@ void GT911::read_reg(uint16_t reg, uint8_t reg_len, uint8_t* r_data, uint8_t r_l
   sw_iic.start();
   sw_iic.send_byte(gt911_slave_address + 1);  // Set read mode
 
-  LOOP_L_N(i, r_len) {
+  LOOP_L_N(i, r_len)
     r_data[i] = sw_iic.read_byte(1);  // Read data from reg
-  }
+
   sw_iic.stop();
 }
 

Marlin/src/HAL/STM32/tft/gt911.h

@@ -39,42 +39,18 @@ class SW_IIC {
   private:
     uint16_t scl_pin;
     uint16_t sda_pin;
-    void write_scl(bool level)
-    {
-      WRITE(scl_pin, level);
-    }
-    void write_sda(bool level)
-    {
-      WRITE(sda_pin, level);
-    }
-    bool read_sda()
-    {
-      return READ(sda_pin);
-    }
-    void set_sda_out()
-    {
-      SET_OUTPUT(sda_pin);
-    }
-    void set_sda_in()
-    {
-      SET_INPUT_PULLUP(sda_pin);
-    }
-    static void iic_delay(uint8_t t)
-    {
-      delayMicroseconds(t);
-    }
+    void write_scl(bool level) { WRITE(scl_pin, level); }
+    void write_sda(bool level) { WRITE(sda_pin, level); }
+    bool read_sda() { return READ(sda_pin); }
+    void set_sda_out() { SET_OUTPUT(sda_pin); }
+    void set_sda_in() { SET_INPUT_PULLUP(sda_pin); }
+    static void iic_delay(uint8_t t) { delayMicroseconds(t); }
 
   public:
     SW_IIC(uint16_t sda, uint16_t scl);
     // setSCL/SDA have to be called before begin()
-    void setSCL(uint16_t scl)
-    {
-      scl_pin = scl;
-    };
-    void setSDA(uint16_t sda)
-    {
-      sda_pin = sda;
-    };
+    void setSCL(uint16_t scl) { scl_pin = scl; }
+    void setSDA(uint16_t sda) { sda_pin = sda; }
     void init();                // Initialize the IO port of IIC
     void start();               // Send IIC start signal
     void stop();                // Send IIC stop signal

Marlin/src/HAL/STM32/tft/tft_fsmc.cpp

@@ -148,20 +148,35 @@ uint32_t TFT_FSMC::ReadID(tft_data_t Reg) {
 
 bool TFT_FSMC::isBusy() {
   #ifdef STM32F1xx
-    volatile bool dmaEnabled = (DMAtx.Instance->CCR & DMA_CCR_EN) != RESET;
+    #define __IS_DMA_ENABLED(__HANDLE__)      ((__HANDLE__)->Instance->CCR & DMA_CCR_EN)
+    #define __IS_DMA_CONFIGURED(__HANDLE__)   ((__HANDLE__)->Instance->CPAR != 0)
   #elif defined(STM32F4xx)
-    volatile bool dmaEnabled = DMAtx.Instance->CR & DMA_SxCR_EN;
+    #define __IS_DMA_ENABLED(__HANDLE__)      ((__HANDLE__)->Instance->CR & DMA_SxCR_EN)
+    #define __IS_DMA_CONFIGURED(__HANDLE__)   ((__HANDLE__)->Instance->PAR != 0)
   #endif
-  if (dmaEnabled) {
-    if (__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TC_FLAG_INDEX(&DMAtx)) != 0 || __HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TE_FLAG_INDEX(&DMAtx)) != 0)
-      Abort();
-  }
-  else
-    Abort();
-  return dmaEnabled;
+
+  if (!__IS_DMA_CONFIGURED(&DMAtx)) return false;
+
+  // Check if DMA transfer error or transfer complete flags are set
+  if ((__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TE_FLAG_INDEX(&DMAtx)) == 0) && (__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TC_FLAG_INDEX(&DMAtx)) == 0)) return true;
+
+  __DSB();
+  Abort();
+  return false;
+}
+
+void TFT_FSMC::Abort() {
+  HAL_DMA_Abort(&DMAtx);  // Abort DMA transfer if any
+  HAL_DMA_DeInit(&DMAtx); // Deconfigure DMA
 }
 
 void TFT_FSMC::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+  DMAtx.Init.PeriphInc = MemoryIncrease;
+  HAL_DMA_Init(&DMAtx);
+  HAL_DMA_Start(&DMAtx, (uint32_t)Data, (uint32_t)&(LCD->RAM), Count);
+}
+
+void TFT_FSMC::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
   DMAtx.Init.PeriphInc = MemoryIncrease;
   HAL_DMA_Init(&DMAtx);
   DataTransferBegin();

Marlin/src/HAL/STM32/tft/tft_fsmc.h

@@ -41,6 +41,7 @@
 #define DATASIZE_8BIT  SPI_DATASIZE_8BIT
 #define DATASIZE_16BIT SPI_DATASIZE_16BIT
 #define TFT_IO_DRIVER  TFT_FSMC
+#define DMA_MAX_SIZE   0xFFFF
 
 #define TFT_DATASIZE TERN(TFT_INTERFACE_FSMC_8BIT, DATASIZE_8BIT, DATASIZE_16BIT)
 typedef TERN(TFT_INTERFACE_FSMC_8BIT, uint8_t, uint16_t) tft_data_t;
@@ -59,13 +60,14 @@ class TFT_FSMC {
 
     static uint32_t ReadID(tft_data_t Reg);
     static void Transmit(tft_data_t Data) { LCD->RAM = Data; __DSB(); }
+    static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
     static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
 
   public:
     static void Init();
     static uint32_t GetID();
     static bool isBusy();
-    static void Abort() { __HAL_DMA_DISABLE(&DMAtx); }
+    static void Abort();
 
     static void DataTransferBegin(uint16_t DataWidth = TFT_DATASIZE) {}
     static void DataTransferEnd() {};
@@ -73,13 +75,14 @@ class TFT_FSMC {
     static void WriteData(uint16_t Data) { Transmit(tft_data_t(Data)); }
     static void WriteReg(uint16_t Reg) { LCD->REG = tft_data_t(Reg); __DSB(); }
 
-    static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_PINC_ENABLE, Data, Count); }
-    static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_PINC_DISABLE, &Data, Count); }
+    static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_PINC_ENABLE, Data, Count); }
+    static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_PINC_DISABLE, &Data, Count); }
+
+    static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_PINC_ENABLE, Data, Count); }
     static void WriteMultiple(uint16_t Color, uint32_t Count) {
-      static uint16_t Data; Data = Color;
       while (Count > 0) {
-        TransmitDMA(DMA_MINC_DISABLE, &Data, Count > 0xFFFF ? 0xFFFF : Count);
-        Count = Count > 0xFFFF ? Count - 0xFFFF : 0;
+        Transmit(DMA_MINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+        Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
       }
     }
 };

Marlin/src/HAL/STM32/tft/tft_ltdc.cpp

@@ -356,7 +356,7 @@ void TFT_LTDC::WriteReg(uint16_t Reg) {
   reg = Reg;
 }
 
-void TFT_LTDC::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+void TFT_LTDC::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
 
   while (x_cur != x_min && Count) {
     Transmit(*Data);

Marlin/src/HAL/STM32/tft/tft_ltdc.h

@@ -32,6 +32,7 @@
 #define DATASIZE_8BIT  SPI_DATASIZE_8BIT
 #define DATASIZE_16BIT SPI_DATASIZE_16BIT
 #define TFT_IO_DRIVER  TFT_LTDC
+#define DMA_MAX_SIZE   0xFFFF
 
 #define TFT_DATASIZE DATASIZE_16BIT
 typedef uint16_t tft_data_t;
@@ -49,7 +50,7 @@ class TFT_LTDC {
     static void DrawRect(uint16_t sx, uint16_t sy, uint16_t ex, uint16_t ey, uint16_t color);
     static void DrawImage(uint16_t sx, uint16_t sy, uint16_t ex, uint16_t ey, uint16_t *colors);
     static void Transmit(tft_data_t Data);
-    static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
+    static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
 
   public:
     static void Init();
@@ -63,13 +64,15 @@ class TFT_LTDC {
     static void WriteData(uint16_t Data);
     static void WriteReg(uint16_t Reg);
 
-    static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_PINC_ENABLE, Data, Count); }
-    static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_PINC_DISABLE, &Data, Count); }
+    // Non-blocking DMA data transfer is not implemented for LTDC interface
+    inline static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { WriteSequence(Data, Count); }
+    inline static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { WriteMultiple(Color, Count); }
+
+    static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_PINC_ENABLE, Data, Count); }
     static void WriteMultiple(uint16_t Color, uint32_t Count) {
-      static uint16_t Data; Data = Color;
       while (Count > 0) {
-        TransmitDMA(DMA_MINC_DISABLE, &Data, Count > 0xFFFF ? 0xFFFF : Count);
-        Count = Count > 0xFFFF ? Count - 0xFFFF : 0;
+        Transmit(DMA_PINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+        Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
       }
     }
 };

Marlin/src/HAL/STM32/tft/tft_spi.cpp

@@ -160,16 +160,13 @@ uint32_t TFT_SPI::ReadID(uint16_t Reg) {
 
     for (i = 0; i < 4; i++) {
       #if TFT_MISO_PIN != TFT_MOSI_PIN
-        //if (hspi->Init.Direction == SPI_DIRECTION_2LINES) {
-          while (!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_TXE)) {}
-          SPIx.Instance->DR = 0;
-        //}
+        while (!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_TXE)) {}
+        SPIx.Instance->DR = 0;
       #endif
       while (!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_RXNE)) {}
       Data = (Data << 8) | SPIx.Instance->DR;
     }
 
-    __HAL_SPI_DISABLE(&SPIx);
     DataTransferEnd();
 
     SPIx.Init.BaudRatePrescaler   = BaudRatePrescaler;
@@ -180,35 +177,43 @@ uint32_t TFT_SPI::ReadID(uint16_t Reg) {
 
 bool TFT_SPI::isBusy() {
   #ifdef STM32F1xx
-    volatile bool dmaEnabled = (DMAtx.Instance->CCR & DMA_CCR_EN) != RESET;
+    #define __IS_DMA_ENABLED(__HANDLE__)      ((__HANDLE__)->Instance->CCR & DMA_CCR_EN)
+    #define __IS_DMA_CONFIGURED(__HANDLE__)   ((__HANDLE__)->Instance->CPAR != 0)
   #elif defined(STM32F4xx)
-    volatile bool dmaEnabled = DMAtx.Instance->CR & DMA_SxCR_EN;
+    #define __IS_DMA_ENABLED(__HANDLE__)      ((__HANDLE__)->Instance->CR & DMA_SxCR_EN)
+    #define __IS_DMA_CONFIGURED(__HANDLE__)   ((__HANDLE__)->Instance->PAR != 0)
   #endif
-  if (dmaEnabled) {
-    if (__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TC_FLAG_INDEX(&DMAtx)) != 0 || __HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TE_FLAG_INDEX(&DMAtx)) != 0)
-      Abort();
+
+  if (!__IS_DMA_CONFIGURED(&DMAtx)) return false;
+
+  if (__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TE_FLAG_INDEX(&DMAtx))) {
+    // You should not be here - DMA transfer error flag is set
+    // Abort DMA transfer and release SPI
   }
-  else
-    Abort();
-  return dmaEnabled;
+  else {
+    // Check if DMA transfer completed flag is set
+    if (__HAL_DMA_GET_FLAG(&DMAtx, __HAL_DMA_GET_TC_FLAG_INDEX(&DMAtx)) == 0) return true;
+    // Check if SPI transmit butter is empty and SPI is idle
+    if ((!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_TXE)) || (__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_BSY))) return true;
+  }
+
+  Abort();
+  return false;
 }
 
 void TFT_SPI::Abort() {
-  // Wait for any running spi
-  while (!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_TXE)) {}
-  while ( __HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_BSY)) {}
-  // First, abort any running dma
-  HAL_DMA_Abort(&DMAtx);
-  // DeInit objects
+  HAL_DMA_Abort(&DMAtx);  // Abort DMA transfer if any
   HAL_DMA_DeInit(&DMAtx);
-  HAL_SPI_DeInit(&SPIx);
-  // Deselect CS
-  DataTransferEnd();
+
+  CLEAR_BIT(SPIx.Instance->CR2, SPI_CR2_TXDMAEN);
+
+  DataTransferEnd();      // Stop SPI and deselect CS
 }
 
 void TFT_SPI::Transmit(uint16_t Data) {
-  if (TFT_MISO_PIN == TFT_MOSI_PIN)
+  #if TFT_MISO_PIN == TFT_MOSI_PIN
     SPI_1LINE_TX(&SPIx);
+  #endif
 
   __HAL_SPI_ENABLE(&SPIx);
 
@@ -217,14 +222,31 @@ void TFT_SPI::Transmit(uint16_t Data) {
   while (!__HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_TXE)) {}
   while ( __HAL_SPI_GET_FLAG(&SPIx, SPI_FLAG_BSY)) {}
 
-  if (TFT_MISO_PIN != TFT_MOSI_PIN)
-    __HAL_SPI_CLEAR_OVRFLAG(&SPIx);   // Clear overrun flag in 2 Lines communication mode because received is not read
+  #if TFT_MISO_PIN != TFT_MOSI_PIN
+    __HAL_SPI_CLEAR_OVRFLAG(&SPIx);   // Clear overrun flag in 2 Lines communication mode because received data is not read
+  #endif
 }
 
 void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
-  // Wait last dma finish, to start another
-  while (isBusy()) { /* nada */ }
+  DMAtx.Init.MemInc = MemoryIncrease;
+  HAL_DMA_Init(&DMAtx);
 
+  #if TFT_MISO_PIN == TFT_MOSI_PIN
+    SPI_1LINE_TX(&SPIx);
+  #endif
+
+  DataTransferBegin();
+
+  HAL_DMA_Start(&DMAtx, (uint32_t)Data, (uint32_t)&(SPIx.Instance->DR), Count);
+  __HAL_SPI_ENABLE(&SPIx);
+
+  SET_BIT(SPIx.Instance->CR2, SPI_CR2_TXDMAEN);   // Enable Tx DMA Request
+
+  TERN_(TFT_SHARED_SPI, while (isBusy()));
+}
+
+
+void TFT_SPI::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
   DMAtx.Init.MemInc = MemoryIncrease;
   HAL_DMA_Init(&DMAtx);
 
@@ -243,7 +265,6 @@ void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Coun
 }
 
 #if ENABLED(USE_SPI_DMA_TC)
-
   void TFT_SPI::TransmitDMA_IT(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
 
     DMAtx.Init.MemInc = MemoryIncrease;
@@ -262,8 +283,7 @@ void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Coun
     SET_BIT(SPIx.Instance->CR2, SPI_CR2_TXDMAEN);   // Enable Tx DMA Request
   }
 
-  extern "C" void DMA2_Stream3_IRQHandler(void) { HAL_DMA_IRQHandler(&TFT_SPI::DMAtx); }
-
+  extern "C" void DMA2_Stream3_IRQHandler(void) { TFT_SPI::DMA_IRQHandler(); }
 #endif
 
 #endif // HAS_SPI_TFT

Marlin/src/HAL/STM32/tft/tft_spi.h

@@ -39,46 +39,47 @@
 #define DATASIZE_8BIT  SPI_DATASIZE_8BIT
 #define DATASIZE_16BIT SPI_DATASIZE_16BIT
 #define TFT_IO_DRIVER  TFT_SPI
+#define DMA_MAX_SIZE   0xFFFF
 
 class TFT_SPI {
 private:
   static SPI_HandleTypeDef SPIx;
-
+  static DMA_HandleTypeDef DMAtx;
 
   static uint32_t ReadID(uint16_t Reg);
   static void Transmit(uint16_t Data);
+  static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
   static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
   #if ENABLED(USE_SPI_DMA_TC)
     static void TransmitDMA_IT(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
   #endif
 
 public:
-  static DMA_HandleTypeDef DMAtx;
-
   static void Init();
   static uint32_t GetID();
   static bool isBusy();
   static void Abort();
 
   static void DataTransferBegin(uint16_t DataWidth = DATASIZE_16BIT);
-  static void DataTransferEnd() { WRITE(TFT_CS_PIN, HIGH); };
+  static void DataTransferEnd() { WRITE(TFT_CS_PIN, HIGH); __HAL_SPI_DISABLE(&SPIx); };
   static void DataTransferAbort();
 
   static void WriteData(uint16_t Data) { Transmit(Data); }
   static void WriteReg(uint16_t Reg) { WRITE(TFT_A0_PIN, LOW); Transmit(Reg); WRITE(TFT_A0_PIN, HIGH); }
 
-  static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
+  static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
+  static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
 
   #if ENABLED(USE_SPI_DMA_TC)
     static void WriteSequenceIT(uint16_t *Data, uint16_t Count) { TransmitDMA_IT(DMA_MINC_ENABLE, Data, Count); }
+    inline static void DMA_IRQHandler() { HAL_DMA_IRQHandler(&TFT_SPI::DMAtx); }
   #endif
 
-  static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
+  static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_MINC_ENABLE, Data, Count); }
   static void WriteMultiple(uint16_t Color, uint32_t Count) {
-    static uint16_t Data; Data = Color;
     while (Count > 0) {
-      TransmitDMA(DMA_MINC_DISABLE, &Data, Count > 0xFFFF ? 0xFFFF : Count);
-      Count = Count > 0xFFFF ? Count - 0xFFFF : 0;
+      Transmit(DMA_MINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+      Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
     }
   }
 };

Marlin/src/HAL/STM32F1/SPI.cpp

@@ -526,23 +526,22 @@ void SPIClass::onReceive(void(*callback)()) {
   _currentSetting->receiveCallback = callback;
   if (callback) {
     switch (_currentSetting->spi_d->clk_id) {
-    #if BOARD_NR_SPI >= 1
-    case RCC_SPI1:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi1EventCallback);
-      break;
-    #endif
-    #if BOARD_NR_SPI >= 2
-    case RCC_SPI2:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi2EventCallback);
-      break;
-    #endif
-    #if BOARD_NR_SPI >= 3
-    case RCC_SPI3:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi3EventCallback);
-      break;
-    #endif
-    default:
-      ASSERT(0);
+      #if BOARD_NR_SPI >= 1
+        case RCC_SPI1:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi1EventCallback);
+          break;
+      #endif
+      #if BOARD_NR_SPI >= 2
+        case RCC_SPI2:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi2EventCallback);
+          break;
+      #endif
+      #if BOARD_NR_SPI >= 3
+        case RCC_SPI3:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaChannel, &SPIClass::_spi3EventCallback);
+          break;
+      #endif
+      default: ASSERT(0);
     }
   }
   else {
@@ -554,23 +553,22 @@ void SPIClass::onTransmit(void(*callback)()) {
   _currentSetting->transmitCallback = callback;
   if (callback) {
     switch (_currentSetting->spi_d->clk_id) {
-    #if BOARD_NR_SPI >= 1
-    case RCC_SPI1:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi1EventCallback);
-      break;
-    #endif
-    #if BOARD_NR_SPI >= 2
-     case RCC_SPI2:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi2EventCallback);
-      break;
-    #endif
-    #if BOARD_NR_SPI >= 3
-    case RCC_SPI3:
-      dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi3EventCallback);
-      break;
-    #endif
-    default:
-      ASSERT(0);
+      #if BOARD_NR_SPI >= 1
+        case RCC_SPI1:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi1EventCallback);
+          break;
+      #endif
+      #if BOARD_NR_SPI >= 2
+         case RCC_SPI2:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi2EventCallback);
+          break;
+      #endif
+      #if BOARD_NR_SPI >= 3
+        case RCC_SPI3:
+          dma_attach_interrupt(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaChannel, &SPIClass::_spi3EventCallback);
+          break;
+      #endif
+      default: ASSERT(0);
     }
   }
   else {

Marlin/src/HAL/STM32F1/SPI.h

@@ -33,6 +33,15 @@
 #include <stdint.h>
 #include <wirish.h>
 
+// Number of SPI ports
+#ifdef BOARD_SPI3_SCK_PIN
+  #define BOARD_NR_SPI 3
+#elif defined(BOARD_SPI2_SCK_PIN)
+  #define BOARD_NR_SPI 2
+#elif defined(BOARD_SPI1_SCK_PIN)
+  #define BOARD_NR_SPI 1
+#endif
+
 // SPI_HAS_TRANSACTION means SPI has
 //   - beginTransaction()
 //   - endTransaction()

Marlin/src/HAL/STM32F1/eeprom_sdcard.cpp

@@ -47,7 +47,7 @@ static char _ALIGN(4) HAL_eeprom_data[MARLIN_EEPROM_SIZE];
 bool PersistentStore::access_start() {
   if (!card.isMounted()) return false;
 
-  SdFile file, root = card.getroot();
+  MediaFile file, root = card.getroot();
   if (!file.open(&root, EEPROM_FILENAME, O_RDONLY))
     return true; // false aborts the save
 
@@ -62,7 +62,7 @@ bool PersistentStore::access_start() {
 bool PersistentStore::access_finish() {
   if (!card.isMounted()) return false;
 
-  SdFile file, root = card.getroot();
+  MediaFile file, root = card.getroot();
   int bytes_written = 0;
   if (file.open(&root, EEPROM_FILENAME, O_CREAT | O_WRITE | O_TRUNC)) {
     bytes_written = file.write(HAL_eeprom_data, MARLIN_EEPROM_SIZE);

Marlin/src/HAL/STM32F1/fast_pwm.cpp

@@ -39,7 +39,7 @@ inline uint8_t timer_and_index_for_pin(const pin_t pin, timer_dev **timer_ptr) {
 void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
   const uint16_t duty = invert ? v_size - v : v;
   if (PWM_PIN(pin)) {
-    timer_dev *timer; UNUSED(timer);
+    timer_dev *timer;
     if (timer_freq[timer_and_index_for_pin(pin, &timer)] == 0)
       set_pwm_frequency(pin, PWM_FREQUENCY);
     const uint8_t channel = PIN_MAP[pin].timer_channel;
@@ -55,7 +55,7 @@ void MarlinHAL::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v
 void MarlinHAL::set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {
   if (!PWM_PIN(pin)) return;                    // Don't proceed if no hardware timer
 
-  timer_dev *timer; UNUSED(timer);
+  timer_dev *timer;
   timer_freq[timer_and_index_for_pin(pin, &timer)] = f_desired;
 
   // Protect used timers

Marlin/src/HAL/STM32F1/onboard_sd.h

@@ -1,11 +1,31 @@
-/*-----------------------------------------------------------------------
-/ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
-/ * Copyright (c) 2019 BigTreeTech [https://github.com/bigtreetech]
-/ * Low level disk interface module include file   (C)ChaN, 2015
-/-----------------------------------------------------------------------*/
-
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
 #pragma once
 
+/*-----------------------------------------------------------------------
+/ * Copyright (c) 2019 BigTreeTech [https://github.com/bigtreetech]
+/ * Low level disk interface module include file (c) ChaN, 2015
+/-----------------------------------------------------------------------*/
+
 #define _DISKIO_WRITE   1   /* 1: Enable disk_write function */
 #define _DISKIO_IOCTL   1   /* 1: Enable disk_ioctl function */
 #define _DISKIO_ISDIO   0   /* 1: Enable iSDIO control function */

Marlin/src/HAL/STM32F1/tft/tft_fsmc.cpp

@@ -215,22 +215,47 @@ uint32_t TFT_FSMC::GetID() {
  }
 
 bool TFT_FSMC::isBusy() {
+  #define __IS_DMA_CONFIGURED(__DMAx__, __CHx__)   (dma_channel_regs(__DMAx__, __CHx__)->CPAR != 0)
+
+  if (!__IS_DMA_CONFIGURED(FSMC_DMA_DEV, FSMC_DMA_CHANNEL)) return false;
+
+  // Check if DMA transfer error or transfer complete flags are set
+  if ((dma_get_isr_bits(FSMC_DMA_DEV, FSMC_DMA_CHANNEL) & (DMA_ISR_TCIF | DMA_ISR_TEIF)) == 0) return true;
+
+  __DSB();
+  Abort();
   return false;
 }
 
 void TFT_FSMC::Abort() {
+  dma_channel_reg_map *channel_regs = dma_channel_regs(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
 
+  dma_disable(FSMC_DMA_DEV, FSMC_DMA_CHANNEL); // Abort DMA transfer if any
+
+  // Deconfigure DMA
+  channel_regs->CCR   = 0U;
+  channel_regs->CNDTR = 0U;
+  channel_regs->CMAR  = 0U;
+  channel_regs->CPAR  = 0U;
 }
 
 void TFT_FSMC::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+  // TODO: HAL STM32 uses DMA2_Channel1 for FSMC on STM32F1
+  dma_setup_transfer(FSMC_DMA_DEV, FSMC_DMA_CHANNEL, Data, DMA_SIZE_16BITS, &LCD->RAM, DMA_SIZE_16BITS, DMA_MEM_2_MEM | MemoryIncrease);
+  dma_set_num_transfers(FSMC_DMA_DEV, FSMC_DMA_CHANNEL, Count);
+  dma_clear_isr_bits(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
+  dma_enable(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
+}
+
+void TFT_FSMC::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
   #if defined(FSMC_DMA_DEV) && defined(FSMC_DMA_CHANNEL)
     dma_setup_transfer(FSMC_DMA_DEV, FSMC_DMA_CHANNEL, Data, DMA_SIZE_16BITS, &LCD->RAM, DMA_SIZE_16BITS, DMA_MEM_2_MEM | MemoryIncrease);
     dma_set_num_transfers(FSMC_DMA_DEV, FSMC_DMA_CHANNEL, Count);
     dma_clear_isr_bits(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
     dma_enable(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
 
-    while ((dma_get_isr_bits(FSMC_DMA_DEV, FSMC_DMA_CHANNEL) & 0x0A) == 0) {};
-    dma_disable(FSMC_DMA_DEV, FSMC_DMA_CHANNEL);
+    while ((dma_get_isr_bits(FSMC_DMA_DEV, FSMC_DMA_CHANNEL) & (DMA_CCR_TEIE | DMA_CCR_TCIE)) == 0) {}
+    Abort();
   #endif
 }
 

Marlin/src/HAL/STM32F1/tft/tft_fsmc.h

@@ -33,6 +33,10 @@
 #define DATASIZE_8BIT  DMA_SIZE_8BITS
 #define DATASIZE_16BIT DMA_SIZE_16BITS
 #define TFT_IO_DRIVER  TFT_FSMC
+#define DMA_MAX_SIZE   0xFFFF
+
+#define DMA_PINC_ENABLE   DMA_PINC_MODE
+#define DMA_PINC_DISABLE  0
 
 typedef struct {
   __IO uint16_t REG;
@@ -45,6 +49,7 @@ class TFT_FSMC {
 
     static uint32_t ReadID(uint16_t Reg);
     static void Transmit(uint16_t Data);
+    static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
     static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
 
   public:
@@ -59,13 +64,14 @@ class TFT_FSMC {
     static void WriteData(uint16_t Data) { Transmit(Data); }
     static void WriteReg(uint16_t Reg);
 
-    static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_PINC_MODE, Data, Count); }
-    static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_CIRC_MODE, &Data, Count); }
+    static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_PINC_ENABLE, Data, Count); }
+    static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_PINC_DISABLE, &Data, Count); }
+
+    static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_PINC_ENABLE, Data, Count); }
     static void WriteMultiple(uint16_t Color, uint32_t Count) {
-      static uint16_t Data; Data = Color;
       while (Count > 0) {
-        TransmitDMA(DMA_CIRC_MODE, &Data, Count > 0xFFFF ? 0xFFFF : Count);
-        Count = Count > 0xFFFF ? Count - 0xFFFF : 0;
+        Transmit(DMA_PINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+        Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
       }
     }
 };

Marlin/src/HAL/STM32F1/tft/tft_spi.cpp

@@ -26,7 +26,7 @@
 
 #include "tft_spi.h"
 
-SPIClass TFT_SPI::SPIx(1);
+SPIClass TFT_SPI::SPIx(TFT_SPI_DEVICE);
 
 void TFT_SPI::Init() {
   #if PIN_EXISTS(TFT_RESET)
@@ -46,7 +46,7 @@ void TFT_SPI::Init() {
    * STM32F1 has 3 SPI ports, SPI1 in APB2, SPI2/SPI3 in APB1
    * so the minimum prescale of SPI1 is DIV4, SPI2/SPI3 is DIV2
    */
-  #if SPI_DEVICE == 1
+  #if TFT_SPI_DEVICE == 1
     #define SPI_CLOCK_MAX SPI_CLOCK_DIV4
   #else
     #define SPI_CLOCK_MAX SPI_CLOCK_DIV2
@@ -62,7 +62,7 @@ void TFT_SPI::Init() {
     case SPI_SPEED_6:       clock = SPI_CLOCK_DIV64; break;
     default:                clock = SPI_CLOCK_DIV2;  // Default from the SPI library
   }
-  SPIx.setModule(1);
+  SPIx.setModule(TFT_SPI_DEVICE);
   SPIx.setClockDivider(clock);
   SPIx.setBitOrder(MSBFIRST);
   SPIx.setDataMode(SPI_MODE0);
@@ -71,7 +71,7 @@ void TFT_SPI::Init() {
 void TFT_SPI::DataTransferBegin(uint16_t DataSize) {
   SPIx.setDataSize(DataSize);
   SPIx.begin();
-  OUT_WRITE(TFT_CS_PIN, LOW);
+  WRITE(TFT_CS_PIN, LOW);
 }
 
 #ifdef TFT_DEFAULT_DRIVER
@@ -113,15 +113,53 @@ uint32_t TFT_SPI::ReadID(uint16_t Reg) {
   #endif
 }
 
-bool TFT_SPI::isBusy() { return false; }
+bool TFT_SPI::isBusy() {
+  #define __IS_DMA_CONFIGURED(__DMAx__, __CHx__)   (dma_channel_regs(__DMAx__, __CHx__)->CPAR != 0)
 
-void TFT_SPI::Abort() { DataTransferEnd(); }
+  if (!__IS_DMA_CONFIGURED(DMAx, DMA_CHx)) return false;
+
+  if (dma_get_isr_bits(DMAx, DMA_CHx) & DMA_ISR_TEIF) {
+    // You should not be here - DMA transfer error flag is set
+    // Abort DMA transfer and release SPI
+  }
+  else {
+    // Check if DMA transfer completed flag is set
+    if (!(dma_get_isr_bits(DMAx, DMA_CHx) & DMA_ISR_TCIF)) return true;
+    // Check if SPI TX butter is empty and SPI is idle
+    if (!(SPIdev->regs->SR & SPI_SR_TXE) || (SPIdev->regs->SR & SPI_SR_BSY)) return true;
+  }
+
+  Abort();
+  return false;
+}
+
+void TFT_SPI::Abort() {
+  dma_channel_reg_map *channel_regs = dma_channel_regs(DMAx, DMA_CHx);
+
+  dma_disable(DMAx, DMA_CHx); // Abort DMA transfer if any
+  spi_tx_dma_disable(SPIdev);
+
+  // Deconfigure DMA
+  channel_regs->CCR   = 0U;
+  channel_regs->CNDTR = 0U;
+  channel_regs->CMAR  = 0U;
+  channel_regs->CPAR  = 0U;
+
+  DataTransferEnd();
+}
 
 void TFT_SPI::Transmit(uint16_t Data) { SPIx.send(Data); }
 
 void TFT_SPI::TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
   DataTransferBegin();
-  OUT_WRITE(TFT_DC_PIN, HIGH);
+  SPIx.dmaSendAsync(Data, Count, MemoryIncrease == DMA_MINC_ENABLE);
+
+  TERN_(TFT_SHARED_SPI, while (isBusy()));
+}
+
+void TFT_SPI::Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count) {
+  WRITE(TFT_DC_PIN, HIGH);
+  DataTransferBegin();
   SPIx.dmaSend(Data, Count, MemoryIncrease == DMA_MINC_ENABLE);
   DataTransferEnd();
 }

Marlin/src/HAL/STM32F1/tft/tft_spi.h

@@ -25,6 +25,27 @@
 
 #include <SPI.h>
 
+#define IS_SPI(N) (BOARD_NR_SPI >= N && (TFT_SCK_PIN == BOARD_SPI##N##_SCK_PIN) && (TFT_MOSI_PIN == BOARD_SPI##N##_MOSI_PIN) && (TFT_MISO_PIN == BOARD_SPI##N##_MISO_PIN))
+#if IS_SPI(1)
+  #define TFT_SPI_DEVICE  1
+  #define SPIdev          SPI1
+  #define DMAx            DMA1
+  #define DMA_CHx         DMA_CH3
+#elif IS_SPI(2)
+  #define TFT_SPI_DEVICE  2
+  #define SPIdev          SPI2
+  #define DMAx            DMA1
+  #define DMA_CHx         DMA_CH5
+#elif IS_SPI(3)
+  #define TFT_SPI_DEVICE  3
+  #define SPIdev          SPI3
+  #define DMAx            DMA2
+  #define DMA_CHx         DMA_CH2
+#else
+  #error "Invalid TFT SPI configuration."
+#endif
+#undef IS_SPI
+
 #ifndef LCD_READ_ID
   #define LCD_READ_ID 0x04   // Read display identification information (0xD3 on ILI9341)
 #endif
@@ -32,17 +53,19 @@
   #define LCD_READ_ID4 0xD3   // Read display identification information (0xD3 on ILI9341)
 #endif
 
-#define DATASIZE_8BIT    DATA_SIZE_8BIT
-#define DATASIZE_16BIT   DATA_SIZE_16BIT
-#define TFT_IO_DRIVER TFT_SPI
+#define DATASIZE_8BIT  DATA_SIZE_8BIT
+#define DATASIZE_16BIT DATA_SIZE_16BIT
+#define TFT_IO_DRIVER  TFT_SPI
+#define DMA_MAX_SIZE   0xFFFF
 
-#define DMA_MINC_ENABLE 1
-#define DMA_MINC_DISABLE 0
+#define DMA_MINC_ENABLE   DMA_MINC_MODE
+#define DMA_MINC_DISABLE  0
 
 class TFT_SPI {
 private:
   static uint32_t ReadID(uint16_t Reg);
   static void Transmit(uint16_t Data);
+  static void Transmit(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
   static void TransmitDMA(uint32_t MemoryIncrease, uint16_t *Data, uint16_t Count);
 
 public:
@@ -58,15 +81,16 @@ public:
   static void DataTransferAbort();
 
   static void WriteData(uint16_t Data) { Transmit(Data); }
-  static void WriteReg(uint16_t Reg) { WRITE(TFT_A0_PIN, LOW); Transmit(Reg); WRITE(TFT_A0_PIN, HIGH); }
+  static void WriteReg(uint16_t Reg) { WRITE(TFT_DC_PIN, LOW); Transmit(Reg); WRITE(TFT_DC_PIN, HIGH); }
 
-  static void WriteSequence(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
-  static void WriteMultiple(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
+  static void WriteSequence_DMA(uint16_t *Data, uint16_t Count) { TransmitDMA(DMA_MINC_ENABLE, Data, Count); }
+  static void WriteMultiple_DMA(uint16_t Color, uint16_t Count) { static uint16_t Data; Data = Color; TransmitDMA(DMA_MINC_DISABLE, &Data, Count); }
+
+  static void WriteSequence(uint16_t *Data, uint16_t Count) { Transmit(DMA_MINC_ENABLE, Data, Count); }
   static void WriteMultiple(uint16_t Color, uint32_t Count) {
-    static uint16_t Data; Data = Color;
     while (Count > 0) {
-      TransmitDMA(DMA_MINC_DISABLE, &Data, Count > 0xFFFF ? 0xFFFF : Count);
-      Count = Count > 0xFFFF ? Count - 0xFFFF : 0;
+      Transmit(DMA_MINC_DISABLE, &Color, Count > DMA_MAX_SIZE ? DMA_MAX_SIZE : Count);
+      Count = Count > DMA_MAX_SIZE ? Count - DMA_MAX_SIZE : 0;
     }
   }
 };

Marlin/src/HAL/platforms.h

@@ -50,6 +50,8 @@
   #define HAL_PATH(PATH, NAME) XSTR(PATH/NATIVE_SIM/NAME)
 #elif defined(__SAMD51__)
   #define HAL_PATH(PATH, NAME) XSTR(PATH/SAMD51/NAME)
+#elif defined(__SAMD21__)
+  #define HAL_PATH(PATH, NAME) XSTR(PATH/SAMD21/NAME)
 #else
   #error "Unsupported Platform!"
 #endif

Marlin/src/HAL/shared/backtrace/unwarm.cpp

@@ -33,8 +33,9 @@
 void UnwPrintf(const char *format, ...) {
   va_list args;
 
-  va_start( args, format );
-  vprintf(format, args );
+  va_start(args, format);
+  vprintf(format, args);
+  va_end(args);
 }
 #endif
 

Marlin/src/HAL/shared/servo.h

@@ -83,10 +83,10 @@
 #else
   #include <stdint.h>
 
-  #if defined(__AVR__) || defined(ARDUINO_ARCH_SAM) || defined(__SAMD51__)
+  #if defined(__AVR__) || defined(ARDUINO_ARCH_SAM) || defined(__SAMD51__) || defined(__SAMD21__)
     // we're good to go
   #else
-    #error "This library only supports boards with an AVR, SAM3X or SAMD51 processor."
+    #error "This library only supports boards with an AVR, SAM3X, SAMD21 or SAMD51 processor."
   #endif
 
   #define Servo_VERSION           2     // software version of this library

Marlin/src/HAL/shared/servo_private.h

@@ -49,8 +49,10 @@
   #include "../DUE/ServoTimers.h"
 #elif defined(__SAMD51__)
   #include "../SAMD51/ServoTimers.h"
+#elif defined(__SAMD21__)
+  #include "../SAMD21/ServoTimers.h"
 #else
-  #error "This library only supports boards with an AVR, SAM3X or SAMD51 processor."
+  #error "This library only supports boards with an AVR, SAM3X, SAMD21 or SAMD51 processor."
 #endif
 
 // Macros