Split transport mirror (#11046)

* Split transport mirror support

* Updated RGB Matrix to respond to electrical events instead of key events

* split matrix slave fix

12 files changed, 93 insertions, 59 deletions

diff --git a/docs/feature_split_keyboard.md b/docs/feature_split_keyboard.md
index c285e353d4..90af3930f9 100644
--- a/docs/feature_split_keyboard.md
+++ b/docs/feature_split_keyboard.md
@@ -191,6 +191,12 @@ communication protocol and may impact the matrix scan speed when enabled.
 The purpose of this feature is to support cosmetic use of modifer state (e.g.
 displaying status on an OLED screen).
 
+```c
+#define SPLIT_TRANSPORT_MIRROR
+```
+
+This mirrors the master side matrix to the slave side for features that react or require knowledge of master side key presses on the slave side.  This adds a few bytes of data to the split communication protocol and may impact the matrix scan speed when enabled. The purpose of this feature is to support cosmetic use of key events (e.g. RGB reacting to Keypresses).
+
 ###  Hardware Configuration Options
 
 There are some settings that you may need to configure, based on how the hardware is set up. 
diff --git a/docs/ja/understanding_qmk.md b/docs/ja/understanding_qmk.md
index 74b37398f8..ab860a6096 100644
--- a/docs/ja/understanding_qmk.md
+++ b/docs/ja/understanding_qmk.md
@@ -147,7 +147,6 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
       * [`bool process_haptic(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/2cee371bf125a6ec541dd7c5a809573facc7c456/drivers/haptic/haptic.c#L216)
       * [`bool process_record_kb(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/keyboards/clueboard/card/card.c#L20)
          * [`bool process_record_user(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/keyboards/clueboard/card/keymaps/default/keymap.c#L58)
-      * [`bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/rgb_matrix.c#L139)
       * [`bool process_midi(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_midi.c#L81)
       * [`bool process_audio(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_audio.c#L19)
       * [`bool process_steno(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_steno.c#L160)
diff --git a/docs/understanding_qmk.md b/docs/understanding_qmk.md
index 9396424258..331b1c893c 100644
--- a/docs/understanding_qmk.md
+++ b/docs/understanding_qmk.md
@@ -142,7 +142,6 @@ The `process_record()` function itself is deceptively simple, but hidden within
     * [`bool process_haptic(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/2cee371bf125a6ec541dd7c5a809573facc7c456/drivers/haptic/haptic.c#L216)
     * [`bool process_record_kb(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/keyboards/clueboard/card/card.c#L20)
       * [`bool process_record_user(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/keyboards/clueboard/card/keymaps/default/keymap.c#L58)
-    * [`bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/rgb_matrix.c#L139)
     * [`bool process_midi(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_midi.c#L81)
     * [`bool process_audio(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_audio.c#L19)
     * [`bool process_steno(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/e1203a222bb12ab9733916164a000ef3ac48da93/quantum/process_keycode/process_steno.c#L160)
diff --git a/quantum/quantum.c b/quantum/quantum.c
index 6d202c515c..38234bb17b 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -221,9 +221,6 @@ bool process_record_quantum(keyrecord_t *record) {
 #ifdef HAPTIC_ENABLE
             process_haptic(keycode, record) &&
 #endif  // HAPTIC_ENABLE
-#if defined(RGB_MATRIX_ENABLE)
-            process_rgb_matrix(keycode, record) &&
-#endif
 #if defined(VIA_ENABLE)
             process_record_via(keycode, record) &&
 #endif
@@ -624,9 +621,6 @@ void matrix_init_quantum() {
 #ifdef AUDIO_ENABLE
     audio_init();
 #endif
-#ifdef RGB_MATRIX_ENABLE
-    rgb_matrix_init();
-#endif
 #if defined(UNICODE_ENABLE) || defined(UNICODEMAP_ENABLE) || defined(UCIS_ENABLE)
     unicode_input_mode_init();
 #endif
@@ -681,10 +675,6 @@ void matrix_scan_quantum() {
     led_matrix_task();
 #endif
 
-#ifdef RGB_MATRIX_ENABLE
-    rgb_matrix_task();
-#endif
-
 #ifdef WPM_ENABLE
     decay_wpm();
 #endif
diff --git a/quantum/rgb_matrix.c b/quantum/rgb_matrix.c
index a945df68e0..ec17b4d72c 100644
--- a/quantum/rgb_matrix.c
+++ b/quantum/rgb_matrix.c
@@ -184,11 +184,12 @@ void rgb_matrix_set_color(int index, uint8_t red, uint8_t green, uint8_t blue) {
 
 void rgb_matrix_set_color_all(uint8_t red, uint8_t green, uint8_t blue) { rgb_matrix_driver.set_color_all(red, green, blue); }
 
-bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record) {
+void process_rgb_matrix(uint8_t row, uint8_t col, bool pressed) {
+#ifndef RGB_MATRIX_SPLIT
+    if (!is_keyboard_master()) return;
+#endif
 #if RGB_DISABLE_TIMEOUT > 0
-    if (record->event.pressed) {
-        rgb_anykey_timer = 0;
-    }
+    rgb_anykey_timer = 0;
 #endif  // RGB_DISABLE_TIMEOUT > 0
 
 #ifdef RGB_MATRIX_KEYREACTIVE_ENABLED
@@ -196,12 +197,12 @@ bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record) {
     uint8_t led_count = 0;
 
 #    if defined(RGB_MATRIX_KEYRELEASES)
-    if (!record->event.pressed)
+    if (!pressed)
 #    elif defined(RGB_MATRIX_KEYPRESSES)
-    if (record->event.pressed)
+    if (pressed)
 #    endif  // defined(RGB_MATRIX_KEYRELEASES)
     {
-        led_count = rgb_matrix_map_row_column_to_led(record->event.key.row, record->event.key.col, led);
+        led_count = rgb_matrix_map_row_column_to_led(row, col, led);
     }
 
     if (last_hit_buffer.count + led_count > LED_HITS_TO_REMEMBER) {
@@ -224,11 +225,9 @@ bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record) {
 
 #if defined(RGB_MATRIX_FRAMEBUFFER_EFFECTS) && !defined(DISABLE_RGB_MATRIX_TYPING_HEATMAP)
     if (rgb_matrix_config.mode == RGB_MATRIX_TYPING_HEATMAP) {
-        process_rgb_matrix_typing_heatmap(record);
+        process_rgb_matrix_typing_heatmap(row, col);
     }
 #endif  // defined(RGB_MATRIX_FRAMEBUFFER_EFFECTS) && !defined(DISABLE_RGB_MATRIX_TYPING_HEATMAP)
-
-    return true;
 }
 
 void rgb_matrix_test(void) {
diff --git a/quantum/rgb_matrix.h b/quantum/rgb_matrix.h
index 8c80c1bff0..bb8bcfab68 100644
--- a/quantum/rgb_matrix.h
+++ b/quantum/rgb_matrix.h
@@ -98,7 +98,7 @@ uint8_t rgb_matrix_map_row_column_to_led(uint8_t row, uint8_t column, uint8_t *l
 void rgb_matrix_set_color(int index, uint8_t red, uint8_t green, uint8_t blue);
 void rgb_matrix_set_color_all(uint8_t red, uint8_t green, uint8_t blue);
 
-bool process_rgb_matrix(uint16_t keycode, keyrecord_t *record);
+void process_rgb_matrix(uint8_t row, uint8_t col, bool pressed);
 
 void rgb_matrix_task(void);
 
diff --git a/quantum/rgb_matrix_animations/typing_heatmap_anim.h b/quantum/rgb_matrix_animations/typing_heatmap_anim.h
index e06437bf76..e7dda11a2f 100644
--- a/quantum/rgb_matrix_animations/typing_heatmap_anim.h
+++ b/quantum/rgb_matrix_animations/typing_heatmap_anim.h
@@ -6,9 +6,7 @@ RGB_MATRIX_EFFECT(TYPING_HEATMAP)
 #            define RGB_MATRIX_TYPING_HEATMAP_DECREASE_DELAY_MS 25
 #        endif
 
-void process_rgb_matrix_typing_heatmap(keyrecord_t* record) {
-    uint8_t row   = record->event.key.row;
-    uint8_t col   = record->event.key.col;
+void process_rgb_matrix_typing_heatmap(uint8_t row, uint8_t col) {
     uint8_t m_row = row - 1;
     uint8_t p_row = row + 1;
     uint8_t m_col = col - 1;
diff --git a/quantum/split_common/matrix.c b/quantum/split_common/matrix.c
index bad762b493..d6636b886a 100644
--- a/quantum/split_common/matrix.c
+++ b/quantum/split_common/matrix.c
@@ -257,7 +257,7 @@ bool matrix_post_scan(void) {
         static uint8_t error_count;
 
         matrix_row_t slave_matrix[ROWS_PER_HAND] = {0};
-        if (!transport_master(slave_matrix)) {
+        if (!transport_master(matrix + thisHand, slave_matrix)) {
             error_count++;
 
             if (error_count > ERROR_DISCONNECT_COUNT) {
@@ -282,7 +282,7 @@ bool matrix_post_scan(void) {
 
         matrix_scan_quantum();
     } else {
-        transport_slave(matrix + thisHand);
+        transport_slave(matrix + thatHand, matrix + thisHand);
 
         matrix_slave_scan_user();
     }
diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index b45ba92c3b..977b5dc33e 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -31,6 +31,9 @@ typedef struct _I2C_slave_buffer_t {
 #    ifndef DISABLE_SYNC_TIMER
     uint32_t sync_timer;
 #    endif
+#    ifdef SPLIT_TRANSPORT_MIRROR
+    matrix_row_t mmatrix[ROWS_PER_HAND];
+#    endif
     matrix_row_t smatrix[ROWS_PER_HAND];
 #    ifdef SPLIT_MODS_ENABLE
     uint8_t real_mods;
@@ -56,7 +59,8 @@ typedef struct _I2C_slave_buffer_t {
 static I2C_slave_buffer_t *const i2c_buffer = (I2C_slave_buffer_t *)i2c_slave_reg;
 
 #    define I2C_SYNC_TIME_START offsetof(I2C_slave_buffer_t, sync_timer)
-#    define I2C_KEYMAP_START offsetof(I2C_slave_buffer_t, smatrix)
+#    define I2C_KEYMAP_MASTER_START offsetof(I2C_slave_buffer_t, mmatrix)
+#    define I2C_KEYMAP_SLAVE_START offsetof(I2C_slave_buffer_t, smatrix)
 #    define I2C_REAL_MODS_START offsetof(I2C_slave_buffer_t, real_mods)
 #    define I2C_WEAK_MODS_START offsetof(I2C_slave_buffer_t, weak_mods)
 #    define I2C_ONESHOT_MODS_START offsetof(I2C_slave_buffer_t, oneshot_mods)
@@ -72,8 +76,11 @@ static I2C_slave_buffer_t *const i2c_buffer = (I2C_slave_buffer_t *)i2c_slave_re
 #    endif
 
 // Get rows from other half over i2c
-bool transport_master(matrix_row_t matrix[]) {
-    i2c_readReg(SLAVE_I2C_ADDRESS, I2C_KEYMAP_START, (void *)matrix, sizeof(i2c_buffer->smatrix), TIMEOUT);
+bool transport_master(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
+    i2c_readReg(SLAVE_I2C_ADDRESS, I2C_KEYMAP_SLAVE_START, (void *)slave_matrix, sizeof(i2c_buffer->smatrix), TIMEOUT);
+#ifdef SPLIT_TRANSPORT_MIRROR
+    i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_KEYMAP_MASTER_START, (void *)master_matrix, sizeof(i2c_buffer->mmatrix), TIMEOUT);
+#endif
 
     // write backlight info
 #    ifdef BACKLIGHT_ENABLE
@@ -141,12 +148,15 @@ bool transport_master(matrix_row_t matrix[]) {
     return true;
 }
 
-void transport_slave(matrix_row_t matrix[]) {
+void transport_slave(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
 #    ifndef DISABLE_SYNC_TIMER
     sync_timer_update(i2c_buffer->sync_timer);
 #    endif
     // Copy matrix to I2C buffer
-    memcpy((void *)i2c_buffer->smatrix, (void *)matrix, sizeof(i2c_buffer->smatrix));
+    memcpy((void*)i2c_buffer->smatrix, (void *)slave_matrix, sizeof(i2c_buffer->smatrix));
+#ifdef SPLIT_TRANSPORT_MIRROR
+    memcpy((void*)master_matrix, (void *)i2c_buffer->mmatrix, sizeof(i2c_buffer->mmatrix));
+#endif
 
 // Read Backlight Info
 #    ifdef BACKLIGHT_ENABLE
@@ -207,6 +217,9 @@ typedef struct _Serial_m2s_buffer_t {
 #    ifndef DISABLE_SYNC_TIMER
     uint32_t sync_timer;
 #    endif
+#    ifdef SPLIT_TRANSPORT_MIRROR
+    matrix_row_t mmatrix[ROWS_PER_HAND];
+#    endif
 #    ifdef BACKLIGHT_ENABLE
     uint8_t  backlight_level;
 #    endif
@@ -289,7 +302,7 @@ void transport_rgblight_slave(void) {
 #        define transport_rgblight_slave()
 #    endif
 
-bool transport_master(matrix_row_t matrix[]) {
+bool transport_master(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
 #    ifndef SERIAL_USE_MULTI_TRANSACTION
     if (soft_serial_transaction() != TRANSACTION_END) {
         return false;
@@ -303,7 +316,10 @@ bool transport_master(matrix_row_t matrix[]) {
 
     // TODO:  if MATRIX_COLS > 8 change to unpack()
     for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        matrix[i] = serial_s2m_buffer.smatrix[i];
+        slave_matrix[i] = serial_s2m_buffer.smatrix[i];
+#ifdef SPLIT_TRANSPORT_MIRROR
+        serial_m2s_buffer.mmatrix[i] = master_matrix[i];
+#endif
     }
 
 #    ifdef BACKLIGHT_ENABLE
@@ -333,7 +349,7 @@ bool transport_master(matrix_row_t matrix[]) {
     return true;
 }
 
-void transport_slave(matrix_row_t matrix[]) {
+void transport_slave(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
     transport_rgblight_slave();
 #    ifndef DISABLE_SYNC_TIMER
     sync_timer_update(serial_m2s_buffer.sync_timer);
@@ -341,7 +357,10 @@ void transport_slave(matrix_row_t matrix[]) {
 
     // TODO: if MATRIX_COLS > 8 change to pack()
     for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        serial_s2m_buffer.smatrix[i] = matrix[i];
+        serial_s2m_buffer.smatrix[i] = slave_matrix[i];
+#ifdef SPLIT_TRANSPORT_MIRROR
+        master_matrix[i] = serial_m2s_buffer.mmatrix[i];
+#endif
     }
 #    ifdef BACKLIGHT_ENABLE
     backlight_set(serial_m2s_buffer.backlight_level);
diff --git a/quantum/split_common/transport.h b/quantum/split_common/transport.h
index c667bfab85..a9f66301bf 100644
--- a/quantum/split_common/transport.h
+++ b/quantum/split_common/transport.h
@@ -6,5 +6,5 @@ void transport_master_init(void);
 void transport_slave_init(void);
 
 // returns false if valid data not received from slave
-bool transport_master(matrix_row_t matrix[]);
-void transport_slave(matrix_row_t matrix[]);
+bool transport_master(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]);
+void transport_slave(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]);
diff --git a/tmk_core/common/eeconfig.h b/tmk_core/common/eeconfig.h
index c4f0483913..d66c4199c2 100644
--- a/tmk_core/common/eeconfig.h
+++ b/tmk_core/common/eeconfig.h
@@ -21,7 +21,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <stdbool.h>
 
 #ifndef EECONFIG_MAGIC_NUMBER
-#    define EECONFIG_MAGIC_NUMBER (uint16_t)0xFEEC
+#    define EECONFIG_MAGIC_NUMBER (uint16_t)0xFEEB // When changing, decrement this value to avoid future re-init issues
 #endif
 #define EECONFIG_MAGIC_NUMBER_OFF (uint16_t)0xFFFF
 
diff --git a/tmk_core/common/keyboard.c b/tmk_core/common/keyboard.c
index 299bda2c12..34fed0caba 100644
--- a/tmk_core/common/keyboard.c
+++ b/tmk_core/common/keyboard.c
@@ -54,6 +54,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifdef RGBLIGHT_ENABLE
 #    include "rgblight.h"
 #endif
+#ifdef RGB_MATRIX_ENABLE
+#    include "rgb_matrix.h"
+#endif
 #ifdef ENCODER_ENABLE
 #    include "encoder.h"
 #endif
@@ -304,6 +307,9 @@ void keyboard_init(void) {
 #ifdef RGBLIGHT_ENABLE
     rgblight_init();
 #endif
+#ifdef RGB_MATRIX_ENABLE
+    rgb_matrix_init();
+#endif
 #ifdef ENCODER_ENABLE
     encoder_init();
 #endif
@@ -328,6 +334,17 @@ void keyboard_init(void) {
     keyboard_post_init_kb(); /* Always keep this last */
 }
 
+/** \brief key_event_task
+ *
+ * This function is responsible for calling into other systems when they need to respond to electrical switch press events.
+ * This is differnet than keycode events as no layer processing, or filtering occurs.
+ */
+void switch_events(uint8_t row, uint8_t col, bool pressed) {
+#if defined(RGB_MATRIX_ENABLE)
+    process_rgb_matrix(row, col, pressed);
+#endif
+}
+
 /** \brief Keyboard task: Do keyboard routine jobs
  *
  * Do routine keyboard jobs:
@@ -358,32 +375,35 @@ void keyboard_task(void) {
     uint8_t matrix_changed = matrix_scan();
     if (matrix_changed) last_matrix_activity_trigger();
 
-    if (should_process_keypress()) {
-        for (uint8_t r = 0; r < MATRIX_ROWS; r++) {
-            matrix_row    = matrix_get_row(r);
-            matrix_change = matrix_row ^ matrix_prev[r];
-            if (matrix_change) {
+    for (uint8_t r = 0; r < MATRIX_ROWS; r++) {
+        matrix_row    = matrix_get_row(r);
+        matrix_change = matrix_row ^ matrix_prev[r];
+        if (matrix_change) {
 #ifdef MATRIX_HAS_GHOST
-                if (has_ghost_in_row(r, matrix_row)) {
-                    continue;
-                }
+            if (has_ghost_in_row(r, matrix_row)) {
+                continue;
+            }
 #endif
-                if (debug_matrix) matrix_print();
-                matrix_row_t col_mask = 1;
-                for (uint8_t c = 0; c < MATRIX_COLS; c++, col_mask <<= 1) {
-                    if (matrix_change & col_mask) {
+            if (debug_matrix) matrix_print();
+            matrix_row_t col_mask = 1;
+            for (uint8_t c = 0; c < MATRIX_COLS; c++, col_mask <<= 1) {
+                if (matrix_change & col_mask) {
+                    if (should_process_keypress()) {
                         action_exec((keyevent_t){
                             .key = (keypos_t){.row = r, .col = c}, .pressed = (matrix_row & col_mask), .time = (timer_read() | 1) /* time should not be 0 */
                         });
-                        // record a processed key
-                        matrix_prev[r] ^= col_mask;
+                    }
+                    // record a processed key
+                    matrix_prev[r] ^= col_mask;
+
+                    switch_events(r, c, (matrix_row & col_mask));
+
 #ifdef QMK_KEYS_PER_SCAN
-                        // only jump out if we have processed "enough" keys.
-                        if (++keys_processed >= QMK_KEYS_PER_SCAN)
+                    // only jump out if we have processed "enough" keys.
+                    if (++keys_processed >= QMK_KEYS_PER_SCAN)
 #endif
-                            // process a key per task call
-                            goto MATRIX_LOOP_END;
-                    }
+                        // process a key per task call
+                        goto MATRIX_LOOP_END;
                 }
             }
         }
@@ -405,6 +425,10 @@ MATRIX_LOOP_END:
     rgblight_task();
 #endif
 
+#ifdef RGB_MATRIX_ENABLE
+    rgb_matrix_task();
+#endif
+
 #if defined(BACKLIGHT_ENABLE)
 #    if defined(BACKLIGHT_PIN) || defined(BACKLIGHT_PINS)
     backlight_task();