Rewrite APA102 support (#10894)

* Rewrite APA102 support

The APA102 source was broken by commit 16a15c1cfcbfd0feb2c2cf1383676747e2f97d73 as it did not include the
quantum header. This commit addresses that, as well as other issues with
transferring bytes over the SPI interface, i.e. it was not setting the
clock pin back to low after sending a bit.

The deviation when sending the end frame is kept, but updated to the
latest from the referenced project.

Finally, these changes expose the global LED brightness parameter
of the APA102. Brightness values are configurable through
`APA102_DEFAULT_BRIGHTNESS` and `APA102_MAX_BRIGHTNESS`.

* Fix typo in led brightness extern

* Move driver out of AVR directory and add delay for ARM

* Experimental APA102 support on AVR and ARM

Co-authored-by: Alde Rojas <hello@alde.io>

* Refactor apa102_send_byte() calls to a loop

* Implement io_wait function for ARM

* Move APA102 drivers to own directory, fix copyright notice

* Add APA102 keymap to handwired/onekey

* Simplify RGBLIGHT_ENABLE/DRIVER option handling

Co-authored-by: Mikkel Jeppesen <2756925+Duckle29@users.noreply.github.com>

2 files changed, 32 insertions, 1 deletions

diff --git a/docs/feature_rgb_matrix.md b/docs/feature_rgb_matrix.md
index a9e711c9f2..bb0acba3bb 100644
--- a/docs/feature_rgb_matrix.md
+++ b/docs/feature_rgb_matrix.md
@@ -129,6 +129,28 @@ Configure the hardware via your `config.h`:
 
 ---
 
+### APA102 :id=apa102
+
+There is basic support for APA102 based addressable LED strands. To enable it, add this to your `rules.mk`:
+
+```makefile
+RGB_MATRIX_ENABLE = yes
+RGB_MATRIX_DRIVER = APA102
+```
+
+Configure the hardware via your `config.h`:
+
+```c
+// The pin connected to the data pin of the LEDs
+#define RGB_DI_PIN D7
+// The pin connected to the clock pin of the LEDs
+#define RGB_CI_PIN D6
+// The number of LEDs connected
+#define DRIVER_LED_TOTAL 70
+```
+
+---
+
 From this point forward the configuration is the same for all the drivers. The `led_config_t` struct provides a key electrical matrix to led index lookup table, what the physical position of each LED is on the board, and what type of key or usage the LED if the LED represents. Here is a brief example:
 
 ```c
diff --git a/docs/feature_rgblight.md b/docs/feature_rgblight.md
index 762056b343..f1178c679d 100644
--- a/docs/feature_rgblight.md
+++ b/docs/feature_rgblight.md
@@ -10,6 +10,7 @@ Currently QMK supports the following addressable LEDs (however, the white LED in
 
  * WS2811, WS2812, WS2812B, WS2812C, etc.
  * SK6812, SK6812MINI, SK6805
+ * APA102
 
 These LEDs are called "addressable" because instead of using a wire per color, each LED contains a small microchip that understands a special protocol sent over a single wire. The chip passes on the remaining data to the next LED, allowing them to be chained together. In this way, you can easily control the color of the individual LEDs.
 
@@ -21,11 +22,19 @@ On keyboards with onboard RGB LEDs, it is usually enabled by default. If it is n
 RGBLIGHT_ENABLE = yes
 ```
 
-At minimum you must define the data pin your LED strip is connected to, and the number of LEDs in the strip, in your `config.h`. If your keyboard has onboard RGB LEDs, and you are simply creating a keymap, you usually won't need to modify these.
+For APA102 LEDs, add the following to your `rules.mk`:
+
+```make
+RGBLIGHT_ENABLE = yes
+RGBLIGHT_DRIVER = APA102
+```
+
+At minimum you must define the data pin your LED strip is connected to, and the number of LEDs in the strip, in your `config.h`. For APA102 LEDs, you must also define the clock pin. If your keyboard has onboard RGB LEDs, and you are simply creating a keymap, you usually won't need to modify these.
 
 |Define         |Description                                                                                              |
 |---------------|---------------------------------------------------------------------------------------------------------|
 |`RGB_DI_PIN`   |The pin connected to the data pin of the LEDs                                                            |
+|`RGB_CI_PIN`   |The pin connected to the clock pin of the LEDs (APA102 only)                                             |
 |`RGBLED_NUM`   |The number of LEDs connected                                                                             |
 |`RGBLED_SPLIT` |(Optional) For split keyboards, the number of LEDs connected on each half directly wired to `RGB_DI_PIN` |