Remove superfluous JTAG disable code (#6445)

* Remove superfluous JTAG disable code

* 32A has differently named register

* Accidentally some operators

* 32A also has different JTAG pins

* Wrap disable_jtag() in an ifndef

* Document this new define

* Rename the define, it conflicts with a LUFA thing

Also, move the ifndef wrapping to the call in keyboard_setup()

Makefile

@@ -20,7 +20,10 @@ endif
 override SILENT := false
 
 ifndef SUB_IS_SILENT
-QMK_VERSION := $(shell git describe --abbrev=0 --tags 2>/dev/null)
+ifndef SKIP_GIT
+    QMK_VERSION := $(shell git describe --abbrev=0 --tags 2>/dev/null)
+endif
+
 ifneq ($(QMK_VERSION),)
 $(info QMK Firmware $(QMK_VERSION))
 endif
@@ -94,6 +97,7 @@ $(eval $(call NEXT_PATH_ELEMENT))
 # endif
 
 define GET_KEYBOARDS
+ifndef ALT_GET_KEYBOARDS
     All_RULES_MK := $$(patsubst $(ROOT_DIR)/keyboards/%/rules.mk,%,$$(wildcard $(ROOT_DIR)/keyboards/*/rules.mk))
     All_RULES_MK += $$(patsubst $(ROOT_DIR)/keyboards/%/rules.mk,%,$$(wildcard $(ROOT_DIR)/keyboards/*/*/rules.mk))
     All_RULES_MK += $$(patsubst $(ROOT_DIR)/keyboards/%/rules.mk,%,$$(wildcard $(ROOT_DIR)/keyboards/*/*/*/rules.mk))
@@ -105,6 +109,9 @@ define GET_KEYBOARDS
     KEYMAPS_MK += $$(patsubst $(ROOT_DIR)/keyboards/%/rules.mk,%,$$(wildcard $(ROOT_DIR)/keyboards/*/*/*/*/keymaps/*/rules.mk))
 
     KEYBOARDS := $$(sort $$(filter-out $$(KEYMAPS_MK), $$(All_RULES_MK)))
+else
+    KEYBOARDS := $(shell find keyboards/ -type f -iname "rules.mk" | grep -v keymaps | sed 's!keyboards/\(.*\)/rules.mk!\1!' | sort | uniq)
+endif
 endef
 
 $(eval $(call GET_KEYBOARDS))

Vagrantfile

@@ -52,26 +52,37 @@ Vagrant.configure(2) do |config|
   end
 
   # Docker provider pulls from hub.docker.com respecting docker.image if
-  # config.vm.box is nil. Note that this bind-mounts from the current dir to
+  # config.vm.box is nil. In this case, we adhoc build util/vagrant/Dockerfile.
+  # Note that this bind-mounts from the current dir to
   # /vagrant in the guest, so unless your UID is 1000 to match vagrant in the
   # image, you'll need to: chmod -R a+rw .
   config.vm.provider "docker" do |docker, override|
     override.vm.box = nil
-    docker.image = "jesselang/debian-vagrant:stretch"
+    docker.build_dir = "util/vagrant"
     docker.has_ssh = true
   end
 
-  # This script ensures the required packages for AVR programming are installed
-  # It also ensures the system always gets the latest updates when powered on
-  # If this causes issues you can run a 'vagrant destroy' and then
-  # add a # before ,run: (or change "always" to "once") and run 'vagrant up' to get a working
-  # non-updated box and then attempt to troubleshoot or open a Github issue
-  config.vm.provision "shell", inline: "/vagrant/util/qmk_install.sh", run: "always"
+  # Unless we are running the docker container directly
+  #   1. run container detached on vm
+  #   2. attach on 'vagrant ssh'
+  ["virtualbox", "vmware_workstation", "vmware_fusion"].each do |type|
+    config.vm.provider type do |virt, override|
+      override.vm.provision "docker" do |d|
+        d.run "qmkfm/base_container",
+          cmd: "tail -f /dev/null",
+          args: "--privileged -v /dev:/dev -v '/vagrant:/vagrant'"
+      end
+
+      override.vm.provision "shell", inline: <<-SHELL
+        echo 'docker restart qmkfm-base_container && exec docker exec -it qmkfm-base_container /bin/bash -l' >> ~vagrant/.bashrc
+      SHELL
+    end
+  end
 
   config.vm.post_up_message = <<-EOT
 
-  Log into the VM using 'vagrant ssh'. QMK directory synchronized with host is
-  located at /vagrant
+  Log into the environment using 'vagrant ssh'. QMK directory synchronized with
+  host is located at /vagrant
   To compile the .hex files use make command inside this directory, e.g.
      cd /vagrant
      make <keyboard>:default

bin/qmk

@@ -38,7 +38,7 @@ with open('requirements.txt', 'r') as fd:
 
 # Figure out our version
 command = ['git', 'describe', '--abbrev=6', '--dirty', '--always', '--tags']
-result = subprocess.run(command, text=True, capture_output=True)
+result = subprocess.run(command, universal_newlines=True, capture_output=True)
 
 if result.returncode == 0:
     os.environ['QMK_VERSION'] = 'QMK ' + result.stdout.strip()

bootloader.mk

@@ -76,6 +76,10 @@ ifeq ($(strip $(BOOTLOADER)), bootloadHID)
     OPT_DEFS += -DBOOTLOADER_BOOTLOADHID
     BOOTLOADER_SIZE = 4096
 endif
+ifeq ($(strip $(BOOTLOADER)), USBasp)
+    OPT_DEFS += -DBOOTLOADER_USBASP
+    BOOTLOADER_SIZE = 4096
+endif
 
 ifdef BOOTLOADER_SIZE
     OPT_DEFS += -DBOOTLOADER_SIZE=$(strip $(BOOTLOADER_SIZE))

build_json.mk

@@ -23,5 +23,5 @@ endif
 
 # Generate the keymap.c
 ifneq ("$(KEYMAP_JSON)","")
-    _ = $(shell bin/qmk-json-keymap -f $(KEYMAP_JSON) -o $(KEYMAP_C))
+    _ = $(shell test -e $(KEYMAP_C) || bin/qmk-json-keymap $(KEYMAP_JSON) -o $(KEYMAP_C))
 endif

build_keyboard.mk

@@ -398,6 +398,7 @@ $(KEYBOARD_OUTPUT)_CONFIG := $(PROJECT_CONFIG)
 all: build check-size
 build: elf cpfirmware
 check-size: build
+objs-size: build
 
 include show_options.mk
 include $(TMK_PATH)/rules.mk

docs/_summary.md

@@ -77,6 +77,7 @@
   * [RGB Lighting](feature_rgblight.md)
   * [RGB Matrix](feature_rgb_matrix.md)
   * [Space Cadet](feature_space_cadet.md)
+  * [Split Keyboard](feature_split_keyboard.md)
   * [Stenography](feature_stenography.md)
   * [Swap Hands](feature_swap_hands.md)
   * [Tap Dance](feature_tap_dance.md)

docs/config_options.md

@@ -76,7 +76,7 @@ This is a C header file that is one of the first things included, and will persi
 * `#define B7_AUDIO`
   * enables audio on pin B7 (duophony is enables if one of B[5-7]\_AUDIO is enabled along with one of C[4-6]\_AUDIO)
 * `#define BACKLIGHT_PIN B7`
-  * pin of the backlight - `B5`, `B6`, `B7` and `C6` (and `D4` on ATmega32A) use hardware PWM, others use software implementation
+  * pin of the backlight
 * `#define BACKLIGHT_LEVELS 3`
   * number of levels your backlight will have (maximum 15 excluding off)
 * `#define BACKLIGHT_BREATHING`
@@ -89,7 +89,7 @@ This is a C header file that is one of the first things included, and will persi
   * mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap
 * `#define LOCKING_RESYNC_ENABLE`
   * tries to keep switch state consistent with keyboard LED state
-* `#define IS_COMMAND() (get_mods() == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)))`
+* `#define IS_COMMAND() (get_mods() == MOD_MASK_SHIFT)`
   * key combination that allows the use of magic commands (useful for debugging)
 * `#define USB_MAX_POWER_CONSUMPTION`
   * sets the maximum power (in mA) over USB for the device (default: 500)
@@ -171,8 +171,8 @@ If you define these options you will enable the associated feature, which may in
   * how long for the Combo keys to be detected. Defaults to `TAPPING_TERM` if not defined.
 * `#define TAP_CODE_DELAY 100`
   * Sets the delay between `register_code` and `unregister_code`, if you're having issues with it registering properly (common on VUSB boards). The value is in milliseconds.
-* `#define TAP_HOLD_CAPS_DELAY 200`
-  * Sets the delay for Tap Hold keys (`LT`, `MT`) when using `KC_CAPSLOCK` keycode, as this has some special handling on MacOS.  The value is in milliseconds, and defaults to 200ms if not defined. 
+* `#define TAP_HOLD_CAPS_DELAY 80`
+  * Sets the delay for Tap Hold keys (`LT`, `MT`) when using `KC_CAPSLOCK` keycode, as this has some special handling on MacOS.  The value is in milliseconds, and defaults to 80 ms if not defined. For macOS, you may want to set this to 200 or higher.
 
 ## RGB Light Configuration
 
@@ -248,6 +248,9 @@ There are a few different ways to set handedness for split keyboards (listed in
 * `#define MATRIX_COL_PINS_RIGHT { <col pins> }`
   * If you want to specify a different pinout for the right half than the left half, you can define `MATRIX_ROW_PINS_RIGHT`/`MATRIX_COL_PINS_RIGHT`. Currently, the size of `MATRIX_ROW_PINS` must be the same as `MATRIX_ROW_PINS_RIGHT` and likewise for the definition of columns.
 
+* `#define DIRECT_PINS_RIGHT { { F1, F0, B0, C7 }, { F4, F5, F6, F7 } }`
+  * If you want to specify a different direct pinout for the right half than the left half, you can define `DIRECT_PINS_RIGHT`. Currently, the size of `DIRECT_PINS` must be the same as `DIRECT_PINS_RIGHT`.
+
 * `#define RGBLED_SPLIT { 6, 6 }`
   * See [RGB Light Configuration](#rgb-light-configuration)
 
@@ -289,6 +292,7 @@ This is a [make](https://www.gnu.org/software/make/manual/make.html) file that i
   * `halfkay`
   * `caterina`
   * `bootloadHID`
+  * `USBasp`
 
 ## Feature Options
 

docs/faq_build.md

@@ -19,7 +19,11 @@ Note that running `make` with `sudo` is generally ***not*** a good idea, and you
 
 ### Linux `udev` Rules
 On Linux, you'll need proper privileges to access the MCU. You can either use
-`sudo` when flashing firmware, or place these files in `/etc/udev/rules.d/`.
+`sudo` when flashing firmware, or place these files in `/etc/udev/rules.d/`. Once added run the following:
+```console
+sudo udevadm control --reload-rules
+sudo udevadm trigger
+```
 
 **/etc/udev/rules.d/50-atmel-dfu.rules:**
 ```
@@ -43,21 +47,41 @@ SUBSYSTEMS=="usb", ATTRS{idVendor}=="feed", MODE:="0666"
 SUBSYSTEMS=="usb", ATTRS{idVendor}=="1c11", MODE:="0666"
 ```
 
+**/etc/udev/rules.d/55-catalina.rules:**
+```
+# ModemManager should ignore the following devices
+ATTRS{idVendor}=="2a03", ENV{ID_MM_DEVICE_IGNORE}="1"
+ATTRS{idVendor}=="2341", ENV{ID_MM_DEVICE_IGNORE}="1"
+```
+
+**Note:** ModemManager filtering only works when not in strict mode, the following commands can update that settings:
+```console
+sudo sed -i 's/--filter-policy=strict/--filter-policy=default/' /lib/systemd/system/ModemManager.service
+sudo systemctl daemon-reload
+sudo systemctl restart ModemManager
+```
+
+**/etc/udev/rules.d/56-dfu-util.rules:**
+```
+# stm32duino
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="1eaf", ATTRS{idProduct}=="0003", MODE:="0666"
+# Generic stm32
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="df11", MODE:="0666"
+```
+
 ### Serial device is not detected in bootloader mode on Linux
 Make sure your kernel has appropriate support for your device. If your device uses USB ACM, such as
 Pro Micro (Atmega32u4), make sure to include `CONFIG_USB_ACM=y`. Other devices may require `USB_SERIAL` and any of its sub options.
 
 ## Unknown Device for DFU Bootloader
 
-If you're using Windows to flash your keyboard, and you are running into issues, check the Device Manager.  If you see an "Unknown Device" when the keyboard is in "bootloader mode", then you may have a driver issue.
+Issues encountered when flashing keyboards on Windows are most often due to having the wrong drivers installed for the bootloader. 
 
-Re-running the installation script for MSYS2 may help (eg run `./util/qmk_install.sh` from MSYS2/WSL) or reinstalling the QMK Toolbox may fix the issue.
+Re-running the installation script for MSYS2 may help (eg run `util/qmk_install.sh` from MSYS2/WSL) or reinstalling the QMK Toolbox may fix the issue. Alternatively, you can download and run the [`qmk_driver_installer`](https://github.com/qmk/qmk_driver_installer) package.
 
-If that doesn't work, then you may need to grab the [Zadig Utility](https://zadig.akeo.ie/). Download this, find the device in question, and select the `WinUSB` option, and hit "Reinstall driver". Once you've done that, try flashing your board, again.  If that doesn't work, try all of the options, until one works. 
+If that doesn't work, then you may need to grab the [Zadig Utility](https://zadig.akeo.ie/). Download this, and run it on the system.  Then, you will need to reset your board into bootloader mode.  After that, locate the device in question. If the device doesn't show up in the list (or nothing shows up in the list), you may need to enable the `List all devices` option in the `Options` menu.
 
-?> There isn't a best option for which driver should be used here.  Some options work better on some systems than others.  libUSB and WinUSB seem to be the best options here.
-
-If the bootloader doesn't show up in the list for devices, you may need to enable the "List all devices" option in the `Options` menu, and then find the bootloader in question. 
+From here, you will need to know what type of controller the board is using.  You may see it listed in the Device Manager as `ATmega32U4` device (which is an AVR board), or an `STM32` device (Which is an ARM board).  For AVR boards, use `libusb-win32` for the driver. For ARM boards, use the `WinUSB` driver.  Once the correct driver type has been selected, click on the `Replace Driver` button, unplug your board, plug it back in, and reset it again.
 
 
 ## WINAVR is Obsolete

docs/faq_debug.md

@@ -184,22 +184,15 @@ Pressing any key during sleep should wake host.
 
 Arduino Leonardo and micro have **ATMega32U4** and can be used for TMK, though Arduino bootloader may be a problem.
 
+## Enabling JTAG
 
-## Using PF4-7 Pins of USB AVR?
-You need to set JTD bit of MCUCR yourself to use PF4-7 as GPIO. Those pins are configured to serve JTAG function by default. MCUs like ATMega*U* or AT90USB* are affected with this.
+By default, the JTAG debugging interface is disabled as soon as the keyboard starts up. JTAG-capable MCUs come from the factory with the `JTAGEN` fuse set, and it takes over certain pins of the MCU that the board may be using for the switch matrix, LEDs, etc.
 
-If you are using Teensy this isn't needed. Teensy is shipped with JTAGEN fuse bit unprogrammed to disable the function.
+If you would like to keep JTAG enabled, just add the following to your `config.h`:
 
-See this code.
+```c
+#define NO_JTAG_DISABLE
 ```
-    // JTAG disable for PORT F. write JTD bit twice within four cycles.
-    MCUCR |= (1<<JTD);
-    MCUCR |= (1<<JTD);
-```
-https://github.com/tmk/tmk_keyboard/blob/master/keyboard/hbkb/matrix.c#L67
-
-And read **26.5.1 MCU Control Register – MCUCR** of ATMega32U4 datasheet.
-
 
 ## Adding LED Indicators of Lock Keys
 You need your own LED indicators for CapsLock, ScrollLock and NumLock? See this post.

docs/feature_backlight.md

@@ -30,32 +30,31 @@ You should then be able to use the keycodes below to change the backlight level.
 
 This feature is distinct from both the [RGB underglow](feature_rgblight.md) and [RGB matrix](feature_rgb_matrix.md) features as it usually allows for only a single colour per switch, though you can obviously use multiple different coloured LEDs on a keyboard.
 
-Hardware PWM is only supported on certain pins of the MCU, so if the backlighting is not connected to one of them, a software PWM implementation triggered by hardware timer interrupts will be used.
-
 Hardware PWM is supported according to the following table:
 
-| Backlight Pin | Hardware timer          |
-|---------------|-------------------------|
-|`B5`           | Timer 1                 |
-|`B6`           | Timer 1                 |
-|`B7`           | Timer 1                 |
-|`C6`           | Timer 3                 |
-|`D4`           | Timer 1 (ATmega32A only)|
-| other         | Software PWM            |
+|Backlight Pin|AT90USB64/128|ATmega16/32U4|ATmega16/32U2|ATmega32A|
+|-------------|-------------|-------------|-------------|---------|
+|`B5`         |Timer 1      |Timer 1      |             |         |
+|`B6`         |Timer 1      |Timer 1      |             |         |
+|`B7`         |Timer 1      |Timer 1      |Timer 1      |         |
+|`C4`         |Timer 3      |             |             |         |
+|`C5`         |Timer 3      |             |Timer 1      |         |
+|`C6`         |Timer 3      |Timer 3      |Timer 1      |         |
+|`D4`         |             |             |             |Timer 1  |
+|`D5`         |             |             |             |Timer 1  |
 
-The [audio feature](feature_audio.md) also uses hardware timers. Please refer to the following table to know what hardware timer the software PWM will use depending on the audio configuration:
+All other pins will use software PWM. If the [Audio](feature_audio.md) feature is disabled or only using one timer, the backlight PWM can be triggered by a hardware timer:
 
-| Audio Pin(s) | Audio Timer | Software PWM Timer |
-|--------------|-------------|--------------------|
-| `C4`         | Timer 3     | Timer 1            |
-| `C5`         | Timer 3     | Timer 1            |
-| `C6`         | Timer 3     | Timer 1            |
-| `B5`         | Timer 1     | Timer 3            |
-| `B6`         | Timer 1     | Timer 3            |
-| `B7`         | Timer 1     | Timer 3            |
-| `Bx` & `Cx`  | Timer 1 & 3 | None               |
+|Audio Pin|Audio Timer|Software PWM Timer|
+|---------|-----------|------------------|
+|`C4`     |Timer 3    |Timer 1           |
+|`C5`     |Timer 3    |Timer 1           |
+|`C6`     |Timer 3    |Timer 1           |
+|`B5`     |Timer 1    |Timer 3           |
+|`B6`     |Timer 1    |Timer 3           |
+|`B7`     |Timer 1    |Timer 3           |
 
-When all timers are in use for [audio](feature_audio.md), the backlight software PWM will not use a hardware timer, but instead will be triggered during the matrix scan. In this case the backlight doesn't support breathing and might show lighting artifacts (for instance flickering), because the PWM computation might not be called with enough timing precision.
+When both timers are in use for Audio, the backlight PWM will not use a hardware timer, but will instead be triggered during the matrix scan. In this case, breathing is not supported, and the backlight might flicker, because the PWM computation may not be called with enough timing precision.
 
 ## Configuration
 
@@ -65,7 +64,7 @@ To change the behaviour of the backlighting, `#define` these in your `config.h`:
 |---------------------|-------------|-------------------------------------------------------------------------------------------------------------|
 |`BACKLIGHT_PIN`      |`B7`         |The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this|
 |`BACKLIGHT_PINS`     |*Not defined*|experimental: see below for more information                                                                 |
-|`BACKLIGHT_LEVELS`   |`3`          |The number of brightness levels (maximum 15 excluding off)                                                   |
+|`BACKLIGHT_LEVELS`   |`3`          |The number of brightness levels (maximum 31 excluding off)                                                   |
 |`BACKLIGHT_CAPS_LOCK`|*Not defined*|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED)                             |
 |`BACKLIGHT_BREATHING`|*Not defined*|Enable backlight breathing, if supported                                                                     |
 |`BREATHING_PERIOD`   |`6`          |The length of one backlight "breath" in seconds                                                              |
@@ -73,8 +72,10 @@ To change the behaviour of the backlighting, `#define` these in your `config.h`:
 
 ## Backlight On State
 
-Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor *on* and light the LEDs, you must drive the backlight pin, connected to the gate or base, *low*.
-Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case you must `#define BACKLIGHT_ON_STATE 1`, so that when the transistor is on, the pin is driven *high* instead.
+Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor *on* and light the LEDs, you must drive the backlight pin, connected to the gate or base, *high*.
+Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case, when the transistor is on, the pin is driven *low* instead.
+
+This functionality is configured at the keyboard level with the `BACKLIGHT_ON_STATE` define.
 
 ## Multiple backlight pins
 

docs/feature_combo.md

@@ -2,7 +2,7 @@
 
 The Combo feature is a chording type solution for adding custom actions.  It lets you hit multiple keys at once and produce a different effect.  For instance, hitting `A` and `S` within the tapping term would hit `ESC` instead, or have it perform even more complex tasks.
 
-To enable this feature, yu need to add `COMBO_ENABLE = yes` to your `rules.mk`.
+To enable this feature, you need to add `COMBO_ENABLE = yes` to your `rules.mk`.
 
 Additionally, in your `config.h`, you'll need to specify the number of combos that you'll be using, by adding `#define COMBO_COUNT 1` (replacing 1 with the number that you're using).
 <!-- At this time, this is necessary -->
@@ -59,19 +59,12 @@ void process_combo_event(uint8_t combo_index, bool pressed) {
   switch(combo_index) {
     case ZC_COPY:
       if (pressed) {
-        register_code(KC_LCTL);
-        register_code(KC_C);
-        unregister_code(KC_C);
-        unregister_code(KC_LCTL);
+        tap_code16(LCTL(KC_C));
       }
       break;
-
     case XV_PASTE:
       if (pressed) {
-        register_code(KC_LCTL);
-        register_code(KC_V);
-        unregister_code(KC_V);
-        unregister_code(KC_LCTL);
+        tap_code16(LCTL(KC_V));
       }
       break;
   }
@@ -87,3 +80,24 @@ If you're using long combos, or even longer combos, you may run into issues with
 In this case, you can add either `#define EXTRA_LONG_COMBOS` or `#define EXTRA_EXTRA_LONG_COMBOS` in your `config.h` file.
 
 You may also be able to enable action keys by defining `COMBO_ALLOW_ACTION_KEYS`.
+
+## Keycodes 
+
+You can enable, disable and toggle the Combo feature on the fly.  This is useful if you need to disable them temporarily, such as for a game. 
+
+|Keycode   |Description                      |
+|----------|---------------------------------|
+|`CMB_ON`  |Turns on Combo feature           |
+|`CMB_OFF` |Turns off Combo feature          |
+|`CMB_TOG` |Toggles Combo feature on and off |
+
+## User callbacks
+
+In addition to the keycodes, there are a few functions that you can use to set the status, or check it:
+
+|Function   |Description                                                         |
+|-----------|--------------------------------------------------------------------|
+| `combo_enable()`     | Enables the combo feature                               |
+| `combo_disable()`    | Disables the combo feature, and clears the combo buffer |
+| `combo_toggle()`     | Toggles the state of the combo feature                  |
+| `is_combo_enabled()` | Returns the status of the combo feature state (true or false) |

docs/feature_command.md

@@ -16,36 +16,36 @@ To use Command, hold down the key combination defined by the `IS_COMMAND()` macr
 
 If you would like to change the key assignments for Command, `#define` these in your `config.h` at either the keyboard or keymap level. All keycode assignments here must omit the `KC_` prefix.
 
-|Define                              |Default                                                                    |Description                                     |
-|------------------------------------|---------------------------------------------------------------------------|------------------------------------------------|
-|`IS_COMMAND()`                      |<code>(get_mods() == (MOD_BIT(KC_LSHIFT) &#124; MOD_BIT(KC_RSHIFT)))</code>|The key combination to activate Command         |
-|`MAGIC_KEY_SWITCH_LAYER_WITH_FKEYS` |`true`                                                                     |Set default layer with the Function row         |
-|`MAGIC_KEY_SWITCH_LAYER_WITH_NKEYS` |`true`                                                                     |Set default layer with the number keys          |
-|`MAGIC_KEY_SWITCH_LAYER_WITH_CUSTOM`|`false`                                                                    |Set default layer with `MAGIC_KEY_LAYER0..9`    |
-|`MAGIC_KEY_DEBUG`                   |`D`                                                                        |Toggle debugging over serial                    |
-|`MAGIC_KEY_DEBUG_MATRIX`            |`X`                                                                        |Toggle key matrix debugging                     |
-|`MAGIC_KEY_DEBUG_KBD`               |`K`                                                                        |Toggle keyboard debugging                       |
-|`MAGIC_KEY_DEBUG_MOUSE`             |`M`                                                                        |Toggle mouse debugging                          |
-|`MAGIC_KEY_CONSOLE`                 |`C`                                                                        |Enable the Command console                      |
-|`MAGIC_KEY_VERSION`                 |`V`                                                                        |Print the running QMK version to the console    |
-|`MAGIC_KEY_STATUS`                  |`S`                                                                        |Print the current keyboard status to the console|
-|`MAGIC_KEY_HELP`                    |`H`                                                                        |Print Command help to the console               |
-|`MAGIC_KEY_HELP_ALT`                |`SLASH`                                                                    |Print Command help to the console (alternate)   |
-|`MAGIC_KEY_LAYER0`                  |`0`                                                                        |Make layer 0 the default layer                  |
-|`MAGIC_KEY_LAYER0_ALT`              |`GRAVE`                                                                    |Make layer 0 the default layer (alternate)      |
-|`MAGIC_KEY_LAYER1`                  |`1`                                                                        |Make layer 1 the default layer                  |
-|`MAGIC_KEY_LAYER2`                  |`2`                                                                        |Make layer 2 the default layer                  |
-|`MAGIC_KEY_LAYER3`                  |`3`                                                                        |Make layer 3 the default layer                  |
-|`MAGIC_KEY_LAYER4`                  |`4`                                                                        |Make layer 4 the default layer                  |
-|`MAGIC_KEY_LAYER5`                  |`5`                                                                        |Make layer 5 the default layer                  |
-|`MAGIC_KEY_LAYER6`                  |`6`                                                                        |Make layer 6 the default layer                  |
-|`MAGIC_KEY_LAYER7`                  |`7`                                                                        |Make layer 7 the default layer                  |
-|`MAGIC_KEY_LAYER8`                  |`8`                                                                        |Make layer 8 the default layer                  |
-|`MAGIC_KEY_LAYER9`                  |`9`                                                                        |Make layer 9 the default layer                  |
-|`MAGIC_KEY_BOOTLOADER`              |`B`                                                                        |Jump to bootloader                              |
-|`MAGIC_KEY_BOOTLOADER_ALT`          |`ESC`                                                                      |Jump to bootloader (alternate)                  |
-|`MAGIC_KEY_LOCK`                    |`CAPS`                                                                     |Lock the keyboard so nothing can be typed       |
-|`MAGIC_KEY_EEPROM`                  |`E`                                                                        |Print stored EEPROM config to the console       |
-|`MAGIC_KEY_EEPROM_CLEAR`            |`BSPACE`                                                                   |Clear the EEPROM                                |
-|`MAGIC_KEY_NKRO`                    |`N`                                                                        |Toggle N-Key Rollover (NKRO)                    |
-|`MAGIC_KEY_SLEEP_LED`               |`Z`                                                                        |Toggle LED when computer is sleeping            |
+|Define                              |Default                         |Description                                     |
+|------------------------------------|--------------------------------|------------------------------------------------|
+|`IS_COMMAND()`                      |`(get_mods() == MOD_MASK_SHIFT)`|The key combination to activate Command         |
+|`MAGIC_KEY_SWITCH_LAYER_WITH_FKEYS` |`true`                          |Set default layer with the Function row         |
+|`MAGIC_KEY_SWITCH_LAYER_WITH_NKEYS` |`true`                          |Set default layer with the number keys          |
+|`MAGIC_KEY_SWITCH_LAYER_WITH_CUSTOM`|`false`                         |Set default layer with `MAGIC_KEY_LAYER0..9`    |
+|`MAGIC_KEY_DEBUG`                   |`D`                             |Toggle debugging over serial                    |
+|`MAGIC_KEY_DEBUG_MATRIX`            |`X`                             |Toggle key matrix debugging                     |
+|`MAGIC_KEY_DEBUG_KBD`               |`K`                             |Toggle keyboard debugging                       |
+|`MAGIC_KEY_DEBUG_MOUSE`             |`M`                             |Toggle mouse debugging                          |
+|`MAGIC_KEY_CONSOLE`                 |`C`                             |Enable the Command console                      |
+|`MAGIC_KEY_VERSION`                 |`V`                             |Print the running QMK version to the console    |
+|`MAGIC_KEY_STATUS`                  |`S`                             |Print the current keyboard status to the console|
+|`MAGIC_KEY_HELP`                    |`H`                             |Print Command help to the console               |
+|`MAGIC_KEY_HELP_ALT`                |`SLASH`                         |Print Command help to the console (alternate)   |
+|`MAGIC_KEY_LAYER0`                  |`0`                             |Make layer 0 the default layer                  |
+|`MAGIC_KEY_LAYER0_ALT`              |`GRAVE`                         |Make layer 0 the default layer (alternate)      |
+|`MAGIC_KEY_LAYER1`                  |`1`                             |Make layer 1 the default layer                  |
+|`MAGIC_KEY_LAYER2`                  |`2`                             |Make layer 2 the default layer                  |
+|`MAGIC_KEY_LAYER3`                  |`3`                             |Make layer 3 the default layer                  |
+|`MAGIC_KEY_LAYER4`                  |`4`                             |Make layer 4 the default layer                  |
+|`MAGIC_KEY_LAYER5`                  |`5`                             |Make layer 5 the default layer                  |
+|`MAGIC_KEY_LAYER6`                  |`6`                             |Make layer 6 the default layer                  |
+|`MAGIC_KEY_LAYER7`                  |`7`                             |Make layer 7 the default layer                  |
+|`MAGIC_KEY_LAYER8`                  |`8`                             |Make layer 8 the default layer                  |
+|`MAGIC_KEY_LAYER9`                  |`9`                             |Make layer 9 the default layer                  |
+|`MAGIC_KEY_BOOTLOADER`              |`B`                             |Jump to bootloader                              |
+|`MAGIC_KEY_BOOTLOADER_ALT`          |`ESC`                           |Jump to bootloader (alternate)                  |
+|`MAGIC_KEY_LOCK`                    |`CAPS`                          |Lock the keyboard so nothing can be typed       |
+|`MAGIC_KEY_EEPROM`                  |`E`                             |Print stored EEPROM config to the console       |
+|`MAGIC_KEY_EEPROM_CLEAR`            |`BSPACE`                        |Clear the EEPROM                                |
+|`MAGIC_KEY_NKRO`                    |`N`                             |Toggle N-Key Rollover (NKRO)                    |
+|`MAGIC_KEY_SLEEP_LED`               |`Z`                             |Toggle LED when computer is sleeping            |

docs/feature_encoders.md

@@ -6,7 +6,6 @@ Basic encoders are supported by adding this to your `rules.mk`:
 
 and this to your `config.h`:
 
-    #define NUMBER_OF_ENCODERS 1
     #define ENCODERS_PAD_A { B12 }
     #define ENCODERS_PAD_B { B13 }
 
@@ -21,6 +20,15 @@ Additionally, the resolution can be specified in the same file (the default & su
 
     #define ENCODER_RESOLUTION 4
 
+## Split Keyboards
+
+If you are using different pinouts for the encoders on each half of a split keyboard, you can define the pinout for the right half like this:
+
+```c
+#define ENCODERS_PAD_A_RIGHT { encoder1a, encoder2a }
+#define ENCODERS_PAD_B_RIGHT { encoder1b, encoder2b }
+```
+
 ## Callbacks
 
 The callback functions can be inserted into your `<keyboard>.c`:

docs/feature_rgb_matrix.md

@@ -374,6 +374,7 @@ These are defined in [`rgblight_list.h`](https://github.com/qmk/qmk_firmware/blo
 #define RGB_MATRIX_LED_PROCESS_LIMIT (DRIVER_LED_TOTAL + 4) / 5 // limits the number of LEDs to process in an animation per task run (increases keyboard responsiveness)
 #define RGB_MATRIX_LED_FLUSH_LIMIT 16 // limits in milliseconds how frequently an animation will update the LEDs. 16 (16ms) is equivalent to limiting to 60fps (increases keyboard responsiveness)
 #define RGB_MATRIX_MAXIMUM_BRIGHTNESS 200 // limits maximum brightness of LEDs to 200 out of 255. If not defined maximum brightness is set to 255
+#define RGB_MATRIX_STARTUP_MODE RGB_MATRIX_CYCLE_LEFT_RIGHT // Sets the default mode, if none has been set
 ```
 
 ## EEPROM storage

docs/feature_split_keyboard.md

@@ -0,0 +1,197 @@
+# Split Keyboard 
+
+Many keyboards in the QMK Firmware repo are "split" keyboards. They use two controllers—one plugging into USB, and the second connected by a serial or an I<sup>2</sup>C connection over a TRRS or similar cable. 
+
+Split keyboards can have a lot of benefits, but there is some additional work needed to get them enabled.  
+
+QMK Firmware has a generic implementation that is usable by any board, as well as numerous board specific implementations. 
+
+For this, we will mostly be talking about the generic implementation used by the Let's Split and other keyboards. 
+
+!> ARM is not yet supported for Split Keyboards.  Progress is being made, but we are not quite there, yet. 
+
+
+## Hardware Configuration
+
+This assumes that you're using two Pro Micro-compatible controllers, and are using TRRS jacks to connect to two halves. 
+
+### Required Hardware
+
+Apart from diodes and key switches for the keyboard matrix in each half, you will need 2x TRRS sockets and 1x TRRS cable.
+
+Alternatively, you can use any sort of cable and socket that has at least 3 wires. 
+
+If you want to use I<sup>2</sup>C to communicate between halves, you will need a cable with at least 4 wires and 2x 4.7kΩ pull-up resistors.
+
+#### Considerations 
+
+The most commonly used connection is a TRRS cable and jacks.  These provide 4 wires, making them very useful for split keyboards, and are easy to find. 
+
+However, since one of the wires carries VCC, this means that the boards are not hot pluggable. You should always disconnect the board from USB before unplugging and plugging in TRRS cables, or you can short the controller, or worse. 
+
+Another option is to use phone cables (as in, old school RJ-11/RJ-14 cables). Make sure that you use one that actually supports 4 wires/lanes.  
+
+However, USB cables, SATA cables, and even just 4 wires have been known to be used for communication between the controllers. 
+
+!> Using USB cables for communication between the controllers works just fine, but the connector could be mistaken for a normal USB connection and potentially short out the keyboard, depending on how it's wired.  For this reason, they are not recommended for connecting split keyboards.  
+
+### Serial Wiring
+
+The 3 wires of the TRS/TRRS cable need to connect GND, VCC, and D0 (aka PDO or pin 3) between the two Pro Micros. 
+
+?> Note that the pin used here is actually set by `SOFT_SERIAL_PIN` below.
+
+![serial wiring](https://i.imgur.com/C3D1GAQ.png)
+
+### I<sup>2</sup>C Wiring
+
+The 4 wires of the TRRS cable need to connect GND, VCC, and SCL and SDA (aka PD0/pin 3 and PD1/pin 2, respectively) between the two Pro Micros. 
+
+The pull-up resistors may be placed on either half. It is also possible to use 4 resistors and have the pull-ups in both halves, but this is unnecessary in simple use cases.
+
+![I2C wiring](https://i.imgur.com/Hbzhc6E.png)
+
+## Firmware Configuration
+
+To enable the split keyboard feature, add the following to your `rules.mk`: 
+
+```make
+SPLIT_KEYBOARD = yes
+```
+
+If you're using a custom transport (communication method), then you will also need to add: 
+
+```make
+SPLIT_TRANSPORT = custom
+```
+
+### Setting Handedness
+
+By default, the firmware does not know which side is which; it needs some help to determine that. There are several ways to do this, listed in order of precedence.
+
+#### Handedness by Pin
+
+You can configure the firmware to read a pin on the controller to determine handedness.  To do this, add the following to your `config.h` file:
+
+```c
+#define SPLIT_HAND_PIN B7
+```
+
+This will read the specified pin. If it's high, then the controller assumes it is the left hand, and if it's low, it's assumed to be the right side. 
+
+#### Handedness by EEPROM
+
+This method sets the keyboard's handedness by setting a flag in the persistent storage (`EEPROM`).  This is checked when the controller first starts up, and determines what half the keyboard is, and how to orient the keyboard layout. 
+
+
+To enable this method, add the following to your `config.h` file: 
+
+```c
+#define EE_HANDS
+```
+
+However, you'll have to flash the EEPROM files for the correct hand to each controller.  You can do this manually, or there are targets for avrdude and dfu to do this, while flashing the firmware: 
+
+* `:avrdude-split-left`
+* `:avrdude-split-right`
+* `:dfu-split-left`
+* `:dfu-split-right`
+
+This setting is not changed when re-initializing the EEPROM using the `EEP_RST` key, or using the `eeconfig_init()` function.  However, if you reset the EEPROM outside of the firmware's built in options (such as flashing a file that overwrites the `EEPROM`, like how the [QMK Toolbox]()'s "Reset EEPROM" button works), you'll need to re-flash the controller with the `EEPROM` files. 
+
+You can find the `EEPROM` files in the QMK firmware repo, [here](https://github.com/qmk/qmk_firmware/tree/master/quantum/split_common). 
+
+#### Handedness by `#define`
+
+You can set the handedness at compile time.  This is done by adding the following to your `config.h` file:
+
+```c
+#define MASTER_RIGHT
+```
+
+or 
+
+```c
+#define MASTER_LEFT
+```
+
+If neither are defined, the handedness defaults to `MASTER_LEFT`.
+
+
+### Communication Options
+
+Because not every split keyboard is identical, there are a number of additional options that can be configured in your `config.h` file.
+
+```c
+#define USE_I2C
+```
+
+This enables I<sup>2</sup>C support for split keyboards. This isn't strictly for communication, but can be used for OLED or other I<sup>2</sup>C-based devices. 
+
+```c
+#define SOFT_SERIAL_PIN D0
+```
+
+This sets the pin to be used for serial communication. If you're not using serial, you shouldn't need to define this.  
+
+However, if you are using serial and I<sup>2</sup>C on the board, you will need to set this, and to something other than D0 and D1 (as these are used for I<sup>2</sup>C communication).
+
+```c
+#define SELECT_SOFT_SERIAL_SPEED {#}`
+```
+
+If you're having issues with serial communication, you can change this value, as it controls the communication speed for serial.  The default is 1, and the possible values are:
+
+* **`0`**: about 189kbps (Experimental only)
+* **`1`**: about 137kbps (default)
+* **`2`**: about 75kbps
+* **`3`**: about 39kbps
+* **`4`**: about 26kbps
+* **`5`**: about 20kbps
+
+###  Hardware Configuration Options
+
+There are some settings that you may need to configure, based on how the hardware is set up. 
+
+```c
+#define MATRIX_ROW_PINS_RIGHT { <row pins> }
+#define MATRIX_COL_PINS_RIGHT { <col pins> }
+```
+
+This allows you to specify a different set of pins for the matrix on the right side.  This is useful if you have a board with differently-shaped halves that requires a different configuration (such as Keebio's Quefrency).
+
+```c
+#define DIRECT_PINS_RIGHT { { F1, F0, B0, C7 }, { F4, F5, F6, F7 } }
+```
+
+This allows you to specify a different set of direct pins for the right side.
+
+```c
+#define ENCODERS_PAD_A_RIGHT { encoder1a, encoder2a }
+#define ENCODERS_PAD_B_RIGHT { encoder1b, encoder2b }
+```
+
+This allows you to specify a different set of encoder pins for the right side.
+
+```c
+#define RGBLIGHT_SPLIT
+```
+
+This option enables synchronization of the RGB Light modes between the controllers of the split keyboard.  This is for keyboards that have RGB LEDs that are directly wired to the controller (that is, they are not using the "extra data" option on the TRRS cable).
+
+```c
+#define RGBLED_SPLIT { 6, 6 }
+```
+
+This sets how many LEDs are directly connected to each controller.  The first number is the left side, and the second number is the right side.  
+
+?> This setting implies that `RGBLIGHT_SPLIT` is enabled, and will forcibly enable it, if it's not.
+
+
+## Additional Resources
+
+Nicinabox has a [very nice and detailed guide](https://github.com/nicinabox/lets-split-guide) for the Let's Split keyboard, that covers most everything you need to know, including troubleshooting information. 
+
+However, the RGB Light section is out of date, as it was written long before the RGB Split code was added to QMK Firmware. Instead, wire each strip up directly to the controller.
+
+<!-- I may port this information later, but for now ... it's very nice, and covers everything -->

docs/feature_tap_dance.md

@@ -1,22 +1,33 @@
 # Tap Dance: A Single Key Can Do 3, 5, or 100 Different Things
 
-<!-- FIXME: Break this up into multiple sections -->
-
+## Introduction
 Hit the semicolon key once, send a semicolon. Hit it twice, rapidly -- send a colon. Hit it three times, and your keyboard's LEDs do a wild dance. That's just one example of what Tap Dance can do. It's one of the nicest community-contributed features in the firmware, conceived and created by [algernon](https://github.com/algernon) in [#451](https://github.com/qmk/qmk_firmware/pull/451). Here's how algernon describes the feature:
 
 With this feature one can specify keys that behave differently, based on the amount of times they have been tapped, and when interrupted, they get handled before the interrupter.
 
-To make it clear how this is different from `ACTION_FUNCTION_TAP`, let's explore a certain setup! We want one key to send `Space` on single tap, but `Enter` on double-tap.
+## Explanatory Comparison with `ACTION_FUNCTION_TAP`
+`ACTION_FUNCTION_TAP` can offer similar functionality to Tap Dance, but it's worth noting some important differences. To do this, let's explore a certain setup! We want one key to send `Space` on single-tap, but `Enter` on double-tap.
 
-With `ACTION_FUNCTION_TAP`, it is quite a rain-dance to set this up, and has the problem that when the sequence is interrupted, the interrupting key will be sent first. Thus, `SPC a` will result in `a SPC` being sent, if they are typed within `TAPPING_TERM`. With the tap dance feature, that'll come out as `SPC a`, correctly.
+With `ACTION_FUNCTION_TAP`, it is quite a rain-dance to set this up, and has the problem that when the sequence is interrupted, the interrupting key will be sent first. Thus, `SPC a` will result in `a SPC` being sent, if `SPC` and `a` are both typed within `TAPPING_TERM`. With the Tap Dance feature, that'll come out correctly as `SPC a` (even if both `SPC` and `a` are typed within the `TAPPING_TERM`.
 
-The implementation hooks into two parts of the system, to achieve this: into `process_record_quantum()`, and the matrix scan. We need the latter to be able to time out a tap sequence even when a key is not being pressed, so `SPC` alone will time out and register after `TAPPING_TERM` time.
+To achieve this correct handling of interrupts, the implementation of Tap Dance hooks into two parts of the system: `process_record_quantum()`, and the matrix scan. These two parts are explained below, but for now the point to note is that we need the latter to be able to time out a tap sequence even when a key is not being pressed. That way, `SPC` alone will time out and register after `TAPPING_TERM` time.
 
-But lets start with how to use it, first!
+## How to Use Tap Dance
+But enough of the generalities; lets look at how to actually use Tap Dance!
 
-First, you will need `TAP_DANCE_ENABLE=yes` in your `rules.mk`, because the feature is disabled by default. This adds a little less than 1k to the firmware size. Next, you will want to define some tap-dance keys, which is easiest to do with the `TD()` macro, that - similar to `F()`, takes a number, which will later be used as an index into the `tap_dance_actions` array.
+First, you will need `TAP_DANCE_ENABLE=yes` in your `rules.mk`, because the feature is disabled by default. This adds a little less than 1k to the firmware size. 
 
-This array specifies what actions shall be taken when a tap-dance key is in action. Currently, there are five possible options:
+Optionally, you might want to set a custom `TAPPING_TERM` time by adding something like this in you `config.h`:
+
+```
+#define TAPPING_TERM 175
+```
+
+The `TAPPING_TERM` time is the maximum time allowed between taps of your Tap Dance key, and is measured in milliseconds. For example, if you used the above `#define` statement and set up a Tap Dance key that sends `Space` on single-tap and `Enter` on double-tap, then this key will send `ENT` only if you tap this key twice in less than 175ms. If you tap the key, wait more than 175ms, and tap the key again you'll end up sending `SPC SPC` instead. 
+
+Next, you will want to define some tap-dance keys, which is easiest to do with the `TD()` macro, that - similar to `F()` - takes a number, which will later be used as an index into the `tap_dance_actions` array. 
+
+After this, you'll want to use the `tap_dance_actions` array to specify what actions shall be taken when a tap-dance key is in action. Currently, there are five possible options:
 
 * `ACTION_TAP_DANCE_DOUBLE(kc1, kc2)`: Sends the `kc1` keycode when tapped once, `kc2` otherwise. When the key is held, the appropriate keycode is registered: `kc1` when pressed and held, `kc2` when tapped once, then pressed and held.
 * `ACTION_TAP_DANCE_DUAL_ROLE(kc, layer)`: Sends the `kc` keycode when tapped once, or moves to `layer`. (this functions like the `TO` layer keycode).
@@ -24,17 +35,22 @@ This array specifies what actions shall be taken when a tap-dance key is in acti
 * `ACTION_TAP_DANCE_FN_ADVANCED(on_each_tap_fn, on_dance_finished_fn, on_dance_reset_fn)`: Calls the first specified function - defined in the user keymap - on every tap, the second function when the dance action finishes (like the previous option), and the last function when the tap dance action resets.
 * `ACTION_TAP_DANCE_FN_ADVANCED_TIME(on_each_tap_fn, on_dance_finished_fn, on_dance_reset_fn, tap_specific_tapping_term)`: This functions identically to the `ACTION_TAP_DANCE_FN_ADVANCED` function, but uses a custom tapping term for it, instead of the predefined `TAPPING_TERM`.
 
-The first option is enough for a lot of cases, that just want dual roles. For example, `ACTION_TAP_DANCE_DOUBLE(KC_SPC, KC_ENT)` will result in `Space` being sent on single-tap, `Enter` otherwise.
+The first option is enough for a lot of cases, that just want dual roles. For example, `ACTION_TAP_DANCE_DOUBLE(KC_SPC, KC_ENT)` will result in `Space` being sent on single-tap, `Enter` otherwise. 
 
 !> Keep in mind that only [basic keycodes](keycodes_basic.md) are supported here. Custom keycodes are not supported.
 
-And that's the bulk of it!
+Similar to the first option, the second option is good for simple layer-switching cases.
 
-And now, on to the explanation of how it works!
+For more complicated cases, use the third or fourth options (examples of each are listed below). 
 
-The main entry point is `process_tap_dance()`, called from `process_record_quantum()`, which is run for every keypress, and our handler gets to run early. This function checks whether the key pressed is a tap-dance key. If it is not, and a tap-dance was in action, we handle that first, and enqueue the newly pressed key. If it is a tap-dance key, then we check if it is the same as the already active one (if there's one active, that is). If it is not, we fire off the old one first, then register the new one. If it was the same, we increment the counter and the timer.
+Finally, the fifth option is particularly useful if your non-Tap-Dance keys start behaving weirdly after adding the code for your Tap Dance keys. The likely problem is that you changed the `TAPPING_TERM` time to make your Tap Dance keys easier for you to use, and that this has changed the way your other keys handle interrupts.
 
-This means that you have `TAPPING_TERM` time to tap the key again, you do not have to input all the taps within that timeframe. This allows for longer tap counts, with minimal impact on responsiveness.
+## Implementation Details
+Well, that's the bulk of it! You should now be able to work through the examples below, and to develop your own Tap Dance functionality. But if you want a deeper understanding of what's going on behind the scenes, then read on for the explanation of how it all works!
+
+The main entry point is `process_tap_dance()`, called from `process_record_quantum()`, which is run for every keypress, and our handler gets to run early. This function checks whether the key pressed is a tap-dance key. If it is not, and a tap-dance was in action, we handle that first, and enqueue the newly pressed key. If it is a tap-dance key, then we check if it is the same as the already active one (if there's one active, that is). If it is not, we fire off the old one first, then register the new one. If it was the same, we increment the counter and reset the timer.
+
+This means that you have `TAPPING_TERM` time to tap the key again; you do not have to input all the taps within a single `TAPPING_TERM` timeframe. This allows for longer tap counts, with minimal impact on responsiveness.
 
 Our next stop is `matrix_scan_tap_dance()`. This handles the timeout of tap-dance keys.
 
@@ -397,3 +413,111 @@ qk_tap_dance_action_t tap_dance_actions[] = {
 ```
 
 Wrap each tapdance keycode in `TD()` when including it in your keymap, e.g. `TD(ALT_LP)`.
+
+### Example 6: Using tap dance for momentary-layer-switch and layer-toggle keys
+
+Tap Dance can be used to mimic MO(layer) and TG(layer) functionality. For this example, we will set up a key to function as `KC_QUOT` on single-tap, as `MO(_MY_LAYER)` on single-hold, and `TG(_MY_LAYER)` on double-tap.
+
+The first step is to include the following code towards the beginning of your `keymap.c`:
+
+```
+typedef struct {
+  bool is_press_action;
+  int state;
+} tap;
+
+//Define a type for as many tap dance states as you need
+enum {
+  SINGLE_TAP = 1,
+  SINGLE_HOLD = 2,
+  DOUBLE_TAP = 3
+};
+
+enum {
+  QUOT_LAYR = 0     //Our custom tap dance key; add any other tap dance keys to this enum 
+};
+
+//Declare the functions to be used with your tap dance key(s)
+
+//Function associated with all tap dances
+int cur_dance (qk_tap_dance_state_t *state);
+
+//Functions associated with individual tap dances
+void ql_finished (qk_tap_dance_state_t *state, void *user_data);
+void ql_reset (qk_tap_dance_state_t *state, void *user_data);
+
+//Declare variable to track which layer is active
+int active_layer;
+```
+
+The above code is similar to that used in previous examples. The one point to note is that you need to declare a variable to keep track of what layer is currently the active layer. We'll see why shortly.
+
+Towards the bottom of your `keymap.c`, include the following code:
+
+```
+//Update active_layer
+uint32_t layer_state_set_user(uint32_t state) {
+  switch (biton32(state)) {
+    case 1:
+      active_layer = 1;
+      break;
+    case 2:
+      active_layer = 2;
+      break;
+    case 3:
+      active_layer = 3;
+      break;
+    default:
+      active_layer = 0;
+      break;
+  }
+  return state;
+}
+
+//Determine the current tap dance state
+int cur_dance (qk_tap_dance_state_t *state) {
+  if (state->count == 1) {
+    if (!state->pressed) {return SINGLE_TAP;}
+    else return SINGLE_HOLD;
+  } else if (state->count == 2) {return DOUBLE_TAP;}
+  else return 8;
+}
+
+//Initialize tap structure associated with example tap dance key
+static tap ql_tap_state = {
+  .is_press_action = true,
+  .state = 0
+};
+
+//Functions that control what our tap dance key does
+void ql_finished (qk_tap_dance_state_t *state, void *user_data) {
+  ql_tap_state.state = cur_dance(state);
+  switch (ql_tap_state.state) {
+    case SINGLE_TAP: tap_code(KC_QUOT); break;
+    case SINGLE_HOLD: layer_on(_MY_LAYER); break;
+    case DOUBLE_TAP: 
+      if (active_layer==_MY_LAYER) {layer_off(_MY_LAYER);}
+      else layer_on(_MY_LAYER);
+  }
+}
+
+void ql_reset (qk_tap_dance_state_t *state, void *user_data) {
+  if (ql_tap_state.state==SINGLE_HOLD) {layer_off(_MY_LAYER);}
+  ql_tap_state.state = 0;
+}
+
+//Associate our tap dance key with its functionality
+qk_tap_dance_action_t tap_dance_actions[] = {
+  [QUOT_LAYR] = ACTION_TAP_DANCE_FN_ADVANCED_TIME(NULL, ql_finished, ql_reset, 275)
+};
+```
+
+The is where the real logic of our tap dance key gets worked out. Since `layer_state_set_user()` is called on any layer switch, we use it to update `active_layer`. Our example is assuming that your `keymap.c` includes 4 layers, so adjust the switch statement here to fit your actual number of layers.
+
+The use of `cur_dance()` and `ql_tap_state` mirrors the above examples.
+
+The `case:SINGLE_TAP` in `ql_finished` is similar to the above examples. The `case:SINGLE_HOLD` works in conjunction with `ql_reset()` to switch to `_MY_LAYER` while the tap dance key is held, and to switch away from `_MY_LAYER` when the key is released. This mirrors the use of `MO(_MY_LAYER)`. The `case:DOUBLE_TAP` works by checking whether `_MY_LAYER` is the active layer, and toggling it on or off accordingly. This mirrors the use of `TG(_MY_LAYER)`.
+
+`tap_dance_actions[]` works similar to the above examples. Note that I used `ACTION_TAP_DANCE_FN_ADVANCED_TIME()` instead of `ACTION_TAP_DANCE_FN_ADVANCED()`. This is because I like my `TAPPING_TERM` to be short (~175ms) for my non-tap-dance keys but find that this is too quick for me to reliably complete tap dance actions - thus the increased time of 275ms here.
+
+Finally, to get this tap dance key working, be sure to include `TD(QUOT_LAYR)` in your `keymaps[]`.

docs/features.md

@@ -30,6 +30,7 @@ QMK has a staggering number of features for building your keyboard. It can take
 * [RGB Light](feature_rgblight.md) - RGB lighting for your keyboard.
 * [RGB Matrix](feature_rgb_matrix.md) - RGB Matrix lights for per key lighting.
 * [Space Cadet](feature_space_cadet.md) - Use your left/right shift keys to type parenthesis and brackets.
+* [Split Keyboard](feature_split_keyboard.md) 
 * [Stenography](feature_stenography.md) - Put your keyboard into Plover mode for stenography use.
 * [Swap Hands](feature_swap_hands.md) - Mirror your keyboard for one handed usage.
 * [Tap Dance](feature_tap_dance.md) - Make a single key do as many things as you want.

docs/flashing.md

@@ -119,6 +119,31 @@ Flashing sequence:
 3. Flash a .hex file
 4. Reset the device into application mode (may be done automatically)
 
+## USBasploader
+
+USBasploader is a bootloader developed by matrixstorm. It is used in some non-USB AVR chips such as the ATmega328P, which run V-USB.
+
+To ensure compatibility with the USBasploader bootloader, make sure this block is present in your `rules.mk`:
+
+    # Bootloader
+    #     This definition is optional, and if your keyboard supports multiple bootloaders of
+    #     different sizes, comment this out, and the correct address will be loaded
+    #     automatically (+60). See bootloader.mk for all options.
+    BOOTLOADER = USBasp
+
+Compatible flashers:
+
+* [QMK Toolbox](https://github.com/qmk/qmk_toolbox/releases) (recommended GUI)
+* [avrdude](http://www.nongnu.org/avrdude/) with the `usbasp` programmer
+* [AVRDUDESS](https://github.com/zkemble/AVRDUDESS)
+
+Flashing sequence:
+
+1. Press the `RESET` keycode, or keep the boot pin shorted to GND while quickly shorting RST to GND
+2. Wait for the OS to detect the device
+3. Flash a .hex file
+4. Reset the device into application mode (may be done automatically)
+
 ## STM32
 
 All STM32 chips come preloaded with a factory bootloader that cannot be modified nor deleted. Some STM32 chips have bootloaders that do not come with USB programming (e.g. STM32F103) but the process is still the same.

docs/getting_started_make_guide.md

@@ -83,7 +83,7 @@ This allows the keyboard to tell the host OS that up to 248 keys are held down a
 
 `BACKLIGHT_ENABLE`
 
-This enables your backlight on Timer1 and ports B5, B6, or B7 (for now). You can specify your port by putting this in your `config.h`:
+This enables the in-switch LED backlighting. You can specify the backlight pin by putting this in your `config.h`:
 
     #define BACKLIGHT_PIN B7
 

docs/getting_started_vagrant.md

@@ -1,16 +1,20 @@
 # Vagrant Quick Start
 
-This project includes a Vagrantfile that will allow you to build a new firmware for your keyboard very easily without major changes to your primary operating system. This also ensures that when you clone the project and perform a build, you have the exact same environment as anyone else using the Vagrantfile to build. This makes it much easier for people to help you troubleshoot any issues you encounter.
+This project includes a `Vagrantfile` that will allow you to build a new firmware for your keyboard very easily without major changes to your primary operating system. This also ensures that when you clone the project and perform a build, you have the exact same environment as anyone else using the Vagrantfile to build. This makes it much easier for people to help you troubleshoot any issues you encounter.
 
 ## Requirements
 
-Using the `/Vagrantfile` in this repository requires you have [Vagrant](http://www.vagrantup.com/) as well as [VirtualBox](https://www.virtualbox.org/) (or [VMware Workstation](https://www.vmware.com/products/workstation) and [Vagrant VMware plugin](http://www.vagrantup.com/vmware) but the (paid) VMware plugin requires a licensed copy of VMware Workstation/Fusion).
+Using the `Vagrantfile` in this repository requires you have [Vagrant](http://www.vagrantup.com/) as well as a supported provider installed:
 
-*COMPATIBILITY NOTICE* Certain versions of Virtualbox 5 appear to have an incompatibility with the Virtualbox extensions installed in the boxes in this Vagrantfile. If you encounter any issues with the /vagrant mount not succeeding, please upgrade your version of Virtualbox to at least 5.0.12. **Alternately, you can try running the following command:** `vagrant plugin install vagrant-vbguest`
+* [VirtualBox](https://www.virtualbox.org/) (Version at least 5.0.12)
+  * Sold as 'the most accessible platform to use Vagrant'
+* [VMware Workstation](https://www.vmware.com/products/workstation) and [Vagrant VMware plugin](http://www.vagrantup.com/vmware)
+  * The (paid) VMware plugin requires a licensed copy of VMware Workstation/Fusion
+* [Docker](https://www.docker.com/)
 
-Other than having Vagrant and Virtualbox installed and possibly a restart of your computer afterwards, you can simple run a 'vagrant up' anywhere inside the folder where you checked out this project and it will start a Linux virtual machine that contains all the tools required to build this project. There is a post Vagrant startup hint that will get you off on the right foot, otherwise you can also reference the build documentation below.
+Other than having Vagrant, a suitable provider installed and possibly a restart of your computer afterwards, you can simple run a 'vagrant up' anywhere inside the folder where you checked out this project and it will start an environment (either a virtual machine or container) that contains all the tools required to build this project. There is a post Vagrant startup hint that will get you off on the right foot, otherwise you can also reference the build documentation below.
 
-# Flashing the Firmware
+## Flashing the Firmware
 
 The "easy" way to flash the firmware is using a tool from your host OS:
 
@@ -19,3 +23,35 @@ The "easy" way to flash the firmware is using a tool from your host OS:
 * [Atmel FLIP](http://www.atmel.com/tools/flip.aspx)
 
 If you want to program via the command line you can uncomment the ['modifyvm'] lines in the Vagrantfile to enable the USB passthrough into Linux and then program using the command line tools like dfu-util/dfu-programmer or you can install the Teensy CLI version.
+
+## Vagrantfile Overview
+The development environment is configured to run the QMK Docker image, `qmkfm/base_container`. This not only ensures predictability between systems, it also mirrors the CI environment.
+
+## FAQ
+
+### Why am I seeing issues under Virtualbox?
+Certain versions of Virtualbox 5 appear to have an incompatibility with the Virtualbox extensions installed in the boxes in this Vagrantfile. If you encounter any issues with the /vagrant mount not succeeding, please upgrade your version of Virtualbox to at least 5.0.12. **Alternately, you can try running the following command:**
+
+```console
+vagrant plugin install vagrant-vbguest
+```
+
+### How do I remove an existing environment?
+Finished with your environment? From anywhere inside the folder where you checked out this project, Execute:
+
+```console
+vagrant destory
+```
+
+### What if I want to use Docker directly?
+Want to benefit from the Vagrant workflow without a virtual machine? The Vagrantfile is configured to bypass running a virtual machine, and run the container directly. Execute the following when bringing up the environment to force the use of Docker:
+```console
+vagrant up --provider=docker
+```
+
+### How do I access the virtual machine instead of the Docker container?
+Execute the following to bypass the `vagrant` user booting directly to the official qmk builder image:
+
+```console
+vagrant ssh -c 'sudo -i'
+```

docs/hardware_avr.md

@@ -78,7 +78,7 @@ Do change the `MANUFACTURER`, `PRODUCT`, and `DESCRIPTION` lines to accurately r
 #define DESCRIPTION     A custom keyboard
 ```
 
-?> Note: On Windows and macOS the `MANUFACTURER`, `PRODUCT`, and `DESCRIPTION` fields will be displayed in the list of USB devices. ?> On Linux these values will not be visible in lsusb by default, since Linux takes the information from the list maintained by [USB ID Repository](http://www.linux-usb.org/usb-ids.html) by default. lsusb will show the information reported by the device when executed with -v option. It is also present in kernel logs after plugging in the device.
+?> Windows and macOS will display the `MANUFACTURER` and `PRODUCT` in the list of USB devices. `lsusb` on Linux instead takes these from the list maintained by the [USB ID Repository](http://www.linux-usb.org/usb-ids.html) by default. `lsusb -v` will show the values reported by the device, and they are also present in kernel logs after plugging it in.
 
 ### Keyboard Matrix Configuration
 
@@ -125,7 +125,7 @@ To configure a keyboard where each switch is connected to a separate pin and gro
 
 ### Backlight Configuration
 
-By default QMK supports backlighting on pins `B5`, `B6`, and `B7`. If you are using one of those you can simply enable it here. For more details see the [Backlight Documentation](feature_backlight.md).
+QMK supports backlighting on most GPIO pins. A select few of these can be driven by the MCU in hardware. For more details see the [Backlight Documentation](feature_backlight.md).
 
 ```c
 #define BACKLIGHT_PIN B7
@@ -134,8 +134,6 @@ By default QMK supports backlighting on pins `B5`, `B6`, and `B7`. If you are us
 #define BREATHING_PERIOD 6
 ```
 
-?> You can use backlighting on any pin you like, but you will have to do more work to support that. See the [Backlight Documentation](feature_backlight.md) for more details.
-
 ### Other Configuration Options
 
 There are a lot of features that can be configured or tuned in `config.h`. You should see the [Config Options](config_options.md) page for more details.

docs/i2c_driver.md

@@ -73,7 +73,22 @@ STM32 MCUs allows a variety of pins to be configured as I2C pins depending on th
 | `I2C1_SDA`               | The pin number for the SDA pin (0-9)                                                         | `7`     |
 | `I2C1_BANK` (deprecated) | The bank of pins (`GPIOA`, `GPIOB`, `GPIOC`), superceded by `I2C1_SCL_BANK`, `I2C1_SDA_BANK` | `GPIOB` |
 
-STM32 MCUs allow for different timing parameters when configuring I2C. These can be modified using the following parameters, using https://www.st.com/en/embedded-software/stsw-stm32126.html as a reference:
+The ChibiOS I2C driver configuration depends on STM32 MCU:
+
+    STM32F1xx, STM32F2xx, STM32F4xx, STM32L0xx and STM32L1xx use I2Cv1;
+    STM32F0xx, STM32F3xx, STM32F7xx and STM32L4xx use I2Cv2;
+
+#### I2Cv1
+STM32 MCUs allow for different clock and duty parameters when configuring I2Cv1. These can be modified using the following parameters, using <https://www.playembedded.org/blog/stm32-i2c-chibios/#I2Cv1_configuration_structure> as a reference:
+
+| Variable           | Default          |
+|--------------------|------------------|
+| `I2C1_OPMODE`      | `OPMODE_I2C`     |
+| `I2C1_CLOCK_SPEED` | `100000`         |
+| `I2C1_DUTY_CYCLE`  | `STD_DUTY_CYCLE` |
+
+#### I2Cv2
+STM32 MCUs allow for different timing parameters when configuring I2Cv2. These can be modified using the following parameters, using <https://www.st.com/en/embedded-software/stsw-stm32126.html> as a reference:
 
 | Variable              | Default |
 |-----------------------|---------|
@@ -83,13 +98,14 @@ STM32 MCUs allow for different timing parameters when configuring I2C. These can
 | `I2C1_TIMINGR_SCLH`   | `15U`   |
 | `I2C1_TIMINGR_SCLL`   | `21U`   |
 
-STM32 MCUs allow for different "alternate function" modes when configuring GPIO pins. These are required to switch the pins used to I2C mode. See the respective datasheet for the appropriate values for your MCU.
+STM32 MCUs allow for different "alternate function" modes when configuring GPIO pins. These are required to switch the pins used to I2Cv2 mode. See the respective datasheet for the appropriate values for your MCU.
 
 | Variable            | Default |
 |---------------------|---------|
 | `I2C1_SCL_PAL_MODE` | `4`     |
 | `I2C1_SDA_PAL_MODE` | `4`     |
 
+#### Other
 You can also overload the `void i2c_init(void)` function, which has a weak attribute. If you do this the configuration variables above will not be used. Please consult the datasheet of your MCU for the available GPIO configurations. The following is an example initialization function:
 
 ```C

docs/newbs_building_firmware_configurator.md

@@ -4,7 +4,7 @@ The [QMK Configurator](https://config.qmk.fm) is an online graphical user interf
 
 ?> **Please follow these steps in order.**
 
-Watch the [Video Tutorial](https://youtu.be/7RH-1pAbjvw)
+Watch the [Video Tutorial](https://youtu.be/tx54jkRC9ZY)
 
 The QMK Configurator works best with Chrome/Firefox. 
 

docs/newbs_flashing.md

@@ -223,7 +223,7 @@ For the PJRC devices (Teensy's), when you're ready to compile and flash your fir
 
 For example, if your keymap is named "xyverz" and you're building a keymap for an Ergodox or Ergodox EZ, you'll use this command:
 
-    make erdogox_ez:xyverz:teensy
+    make ergodox_ez:xyverz:teensy
 
 Once the firmware finishes compiling, it will output something like this: 
 

docs/porting_your_keyboard_to_qmk_(arm_and_other_chibios_cpus).md

@@ -34,7 +34,7 @@ For the `DIODE_DIRECTION`, most hand-wiring guides will instruct you to wire the
 
 To configure a keyboard where each switch is connected to a separate pin and ground instead of sharing row and column pins, use `DIRECT_PINS`. The mapping defines the pins of each switch in rows and columns, from left to right. Must conform to the sizes within `MATRIX_ROWS` and `MATRIX_COLS`, use `NO_PIN` to fill in blank spaces. Overrides the behaviour of `DIODE_DIRECTION`, `MATRIX_ROW_PINS` and `MATRIX_COL_PINS`.
 
-`BACKLIGHT_PIN` is the pin that your PWM-controlled backlight (if one exists) is hooked-up to. Currently only B5, B6, and B7 are supported.
+`BACKLIGHT_PIN` is the pin that your PWM-controlled backlight (if one exists) is hooked-up to.
 
 `BACKLIGHT_BREATHING` is a fancier backlight feature that adds breathing/pulsing/fading effects to the backlight. It uses the same timer as the normal backlight. These breathing effects must be called by code in your keymap.
 

docs/zh-cn/faq_debug.md

@@ -173,23 +173,6 @@ EXTRAKEY_ENABLE = yes          # 音频控制和系统控制
 
 Arduino Leonardo和micro使用**ATMega32U4**，该芯片TMK可用，但Arduino的bootloader会导致问题。
 
-
-## 在USB AVR使用PF4-7针脚?
-你要置位MCUCR寄存器JTD位来将PF4-7设置为GPIO。这些针脚默认是JTAG功能。 像ATMega*U* or AT90USB*这样的MCU会受影响。
-
-如果是用Teensy的话就不需要了。Tennsy自带JTAGEN位未编程来失能该功能。
-<!--翻译问题：上句可能有错，原文为：Teensy is shipped with JTAGEN fuse bit unprogrammed to disable the function. -->
-代码如下。
-```
-    // F接口JTAG失能。在四个周期内写入两次JTD位。
-    MCUCR |= (1<<JTD);
-    MCUCR |= (1<<JTD);
-```
-https://github.com/tmk/tmk_keyboard/blob/master/keyboard/hbkb/matrix.c#L67
-
-阅读ATMega32U4的datasheet中的**26.5.1 MCU Control Register – MCUCR**。
-
-
 ## 为锁定键添加指示灯
 你要自制CapsLock, ScrollLock 和 NumLock指示灯？见下文。
 

drivers/arm/i2c_master.c

@@ -33,11 +33,17 @@
 static uint8_t i2c_address;
 
 static const I2CConfig i2cconfig = {
+#ifdef USE_I2CV1
+  I2C1_OPMODE,
+  I2C1_CLOCK_SPEED,
+  I2C1_DUTY_CYCLE,
+#else
   STM32_TIMINGR_PRESC(I2C1_TIMINGR_PRESC) |
   STM32_TIMINGR_SCLDEL(I2C1_TIMINGR_SCLDEL) | STM32_TIMINGR_SDADEL(I2C1_TIMINGR_SDADEL) |
   STM32_TIMINGR_SCLH(I2C1_TIMINGR_SCLH)  | STM32_TIMINGR_SCLL(I2C1_TIMINGR_SCLL),
   0,
   0
+#endif
 };
 
 static i2c_status_t chibios_to_qmk(const msg_t* status) {
@@ -61,8 +67,13 @@ void i2c_init(void)
 
   chThdSleepMilliseconds(10);
 
+#ifdef USE_I2CV1
+  palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
+  palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_STM32_ALTERNATE_OPENDRAIN);
+#else
   palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_ALTERNATE(I2C1_SCL_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
   palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_ALTERNATE(I2C1_SDA_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
+#endif
 
   //i2cInit(); //This is invoked by halInit() so no need to redo it.
 }
@@ -106,11 +117,11 @@ i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data,
   return chibios_to_qmk(&status);
 }
 
-i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
+i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
 {
   i2c_address = devaddr;
   i2cStart(&I2C_DRIVER, &i2cconfig);
-  msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), regaddr, 1, data, length, MS2ST(timeout));
+  msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), &regaddr, 1, data, length, MS2ST(timeout));
   return chibios_to_qmk(&status);
 }
 

drivers/arm/i2c_master.h

@@ -22,10 +22,16 @@
  * Please ensure that HAL_USE_I2C is TRUE in the halconf.h file and that
  * STM32_I2C_USE_I2C1 is TRUE in the mcuconf.h file.
  */
+#pragma once
 
 #include "ch.h"
 #include <hal.h>
 
+
+#if defined(STM32F1XX) || defined(STM32F1xx) || defined(STM32F2xx) || defined(STM32F4xx) || defined(STM32L0xx) || defined(STM32L1xx)
+    #define USE_I2CV1
+#endif
+
 #ifdef I2C1_BANK
     #define I2C1_SCL_BANK I2C1_BANK
     #define I2C1_SDA_BANK I2C1_BANK
@@ -46,30 +52,42 @@
     #define I2C1_SDA 7
 #endif
 
-// The default PAL alternate modes are used to signal that the pins are used for I2C
-#ifndef I2C1_SCL_PAL_MODE
-    #define I2C1_SCL_PAL_MODE 4
-#endif
-#ifndef I2C1_SDA_PAL_MODE
-    #define I2C1_SDA_PAL_MODE 4
-#endif
+#ifdef USE_I2CV1
+    #ifndef I2C1_OPMODE
+        #define I2C1_OPMODE OPMODE_I2C
+    #endif
+    #ifndef I2C1_CLOCK_SPEED
+        #define I2C1_CLOCK_SPEED 100000 /* 400000 */
+    #endif
+    #ifndef I2C1_DUTY_CYCLE
+        #define I2C1_DUTY_CYCLE STD_DUTY_CYCLE /* FAST_DUTY_CYCLE_2 */
+    #endif
+#else
+    // The default PAL alternate modes are used to signal that the pins are used for I2C
+    #ifndef I2C1_SCL_PAL_MODE
+        #define I2C1_SCL_PAL_MODE 4
+    #endif
+    #ifndef I2C1_SDA_PAL_MODE
+        #define I2C1_SDA_PAL_MODE 4
+    #endif
 
-// The default timing values below configures the I2C clock to 400khz assuming a 72Mhz clock
-// For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html
-#ifndef I2C1_TIMINGR_PRESC
-    #define I2C1_TIMINGR_PRESC 15U
-#endif
-#ifndef I2C1_TIMINGR_SCLDEL
-    #define I2C1_TIMINGR_SCLDEL 4U
-#endif
-#ifndef I2C1_TIMINGR_SDADEL
-    #define I2C1_TIMINGR_SDADEL 2U
-#endif
-#ifndef I2C1_TIMINGR_SCLH
-    #define I2C1_TIMINGR_SCLH 15U
-#endif
-#ifndef I2C1_TIMINGR_SCLL
-    #define I2C1_TIMINGR_SCLL 21U
+    // The default timing values below configures the I2C clock to 400khz assuming a 72Mhz clock
+    // For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html
+    #ifndef I2C1_TIMINGR_PRESC
+        #define I2C1_TIMINGR_PRESC 15U
+    #endif
+    #ifndef I2C1_TIMINGR_SCLDEL
+        #define I2C1_TIMINGR_SCLDEL 4U
+    #endif
+    #ifndef I2C1_TIMINGR_SDADEL
+        #define I2C1_TIMINGR_SDADEL 2U
+    #endif
+    #ifndef I2C1_TIMINGR_SCLH
+        #define I2C1_TIMINGR_SCLH 15U
+    #endif
+    #ifndef I2C1_TIMINGR_SCLL
+        #define I2C1_TIMINGR_SCLL 21U
+    #endif
 #endif
 
 #ifndef I2C_DRIVER
@@ -88,5 +106,5 @@ i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length,
 i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);
 i2c_status_t i2c_transmit_receive(uint8_t address, uint8_t * tx_body, uint16_t tx_length, uint8_t * rx_body, uint16_t rx_length);
 i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout);
-i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t length, uint16_t timeout);
+i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);
 void i2c_stop(void);

drivers/issi/is31fl3731.c

@@ -71,10 +71,10 @@ uint8_t g_twi_transfer_buffer[20];
 // buffers and the transfers in IS31FL3731_write_pwm_buffer() but it's
 // probably not worth the extra complexity.
 uint8_t g_pwm_buffer[DRIVER_COUNT][144];
-bool g_pwm_buffer_update_required = false;
+bool g_pwm_buffer_update_required[DRIVER_COUNT] = { false };
 
 uint8_t g_led_control_registers[DRIVER_COUNT][18] = { { 0 }, { 0 } };
-bool g_led_control_registers_update_required = false;
+bool g_led_control_registers_update_required[DRIVER_COUNT] = { false };
 
 // This is the bit pattern in the LED control registers
 // (for matrix A, add one to register for matrix B)
@@ -204,7 +204,7 @@ void IS31FL3731_set_color( int index, uint8_t red, uint8_t green, uint8_t blue )
         g_pwm_buffer[led.driver][led.r - 0x24] = red;
         g_pwm_buffer[led.driver][led.g - 0x24] = green;
         g_pwm_buffer[led.driver][led.b - 0x24] = blue;
-        g_pwm_buffer_update_required = true;
+        g_pwm_buffer_update_required[led.driver] = true;
     }
 }
 
@@ -220,12 +220,12 @@ void IS31FL3731_set_led_control_register( uint8_t index, bool red, bool green, b
 {
     is31_led led = g_is31_leds[index];
 
-  uint8_t control_register_r = (led.r - 0x24) / 8;
-  uint8_t control_register_g = (led.g - 0x24) / 8;
-  uint8_t control_register_b = (led.b - 0x24) / 8;
-  uint8_t bit_r = (led.r - 0x24) % 8;
-  uint8_t bit_g = (led.g - 0x24) % 8;
-  uint8_t bit_b = (led.b - 0x24) % 8;
+    uint8_t control_register_r = (led.r - 0x24) / 8;
+    uint8_t control_register_g = (led.g - 0x24) / 8;
+    uint8_t control_register_b = (led.b - 0x24) / 8;
+    uint8_t bit_r = (led.r - 0x24) % 8;
+    uint8_t bit_g = (led.g - 0x24) % 8;
+    uint8_t bit_b = (led.b - 0x24) % 8;
 
     if ( red ) {
         g_led_control_registers[led.driver][control_register_r] |= (1 << bit_r);
@@ -243,28 +243,26 @@ void IS31FL3731_set_led_control_register( uint8_t index, bool red, bool green, b
         g_led_control_registers[led.driver][control_register_b] &= ~(1 << bit_b);
     }
 
-    g_led_control_registers_update_required = true;
+    g_led_control_registers_update_required[led.driver] = true;
 
 }
 
-void IS31FL3731_update_pwm_buffers( uint8_t addr1, uint8_t addr2 )
+void IS31FL3731_update_pwm_buffers( uint8_t addr, uint8_t index )
 {
-    if ( g_pwm_buffer_update_required )
+    if ( g_pwm_buffer_update_required[index] )
     {
-        IS31FL3731_write_pwm_buffer( addr1, g_pwm_buffer[0] );
-        IS31FL3731_write_pwm_buffer( addr2, g_pwm_buffer[1] );
+        IS31FL3731_write_pwm_buffer( addr, g_pwm_buffer[index] );
     }
-    g_pwm_buffer_update_required = false;
+    g_pwm_buffer_update_required[index] = false;
 }
 
-void IS31FL3731_update_led_control_registers( uint8_t addr1, uint8_t addr2 )
+void IS31FL3731_update_led_control_registers( uint8_t addr, uint8_t index )
 {
-    if ( g_led_control_registers_update_required )
+    if ( g_led_control_registers_update_required[index] )
     {
         for ( int i=0; i<18; i++ )
         {
-            IS31FL3731_write_register(addr1, i, g_led_control_registers[0][i] );
-            IS31FL3731_write_register(addr2, i, g_led_control_registers[1][i] );
+            IS31FL3731_write_register( addr, i, g_led_control_registers[index][i] );
         }
     }
 }