4 files changed, 106 insertions, 19 deletions

diff --git a/quantum/encoder.c b/quantum/encoder.c
index 6629a098b..ddf6234ab 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -17,6 +17,10 @@
 
 #include "encoder.h"
 
+// for memcpy
+#include <string.h>
+
+
 #ifndef ENCODER_RESOLUTION
   #define ENCODER_RESOLUTION 4
 #endif
@@ -35,7 +39,13 @@ static pin_t encoders_pad_b[NUMBER_OF_ENCODERS] = ENCODERS_PAD_B;
 static int8_t encoder_LUT[] = { 0, -1, 1, 0, 1, 0, 0, -1, -1, 0, 0, 1, 0, 1, -1, 0 };
 
 static uint8_t encoder_state[NUMBER_OF_ENCODERS] = {0};
+
+#ifdef SPLIT_KEYBOARD
+// slave half encoders come over as second set of encoders
+static int8_t encoder_value[NUMBER_OF_ENCODERS * 2] = {0};
+#else
 static int8_t encoder_value[NUMBER_OF_ENCODERS] = {0};
+#endif
 
 __attribute__ ((weak))
 void encoder_update_user(int8_t index, bool clockwise) { }
@@ -60,11 +70,30 @@ void encoder_read(void) {
     encoder_state[i] |= (readPin(encoders_pad_a[i]) << 0) | (readPin(encoders_pad_b[i]) << 1);
     encoder_value[i] += encoder_LUT[encoder_state[i] & 0xF];
     if (encoder_value[i] >= ENCODER_RESOLUTION) {
-        encoder_update_kb(i, COUNTRECLOCKWISE);
+        encoder_update_kb(i, false);
     }
     if (encoder_value[i] <= -ENCODER_RESOLUTION) { // direction is arbitrary here, but this clockwise
-        encoder_update_kb(i, CLOCKWISE);
+        encoder_update_kb(i, true);
     }
     encoder_value[i] %= ENCODER_RESOLUTION;
   }
 }
+
+#ifdef SPLIT_KEYBOARD
+void encoder_state_raw(uint8_t* slave_state) {
+  memcpy(slave_state, encoder_state, sizeof(encoder_state));
+}
+
+void encoder_update_raw(uint8_t* slave_state) {
+  for (int i = 0; i < NUMBER_OF_ENCODERS; i++) {
+    encoder_value[NUMBER_OF_ENCODERS + i] += encoder_LUT[slave_state[i] & 0xF];
+    if (encoder_value[NUMBER_OF_ENCODERS + i] >= ENCODER_RESOLUTION) {
+        encoder_update_kb(NUMBER_OF_ENCODERS + i, false);
+    }
+    if (encoder_value[NUMBER_OF_ENCODERS + i] <= -ENCODER_RESOLUTION) { // direction is arbitrary here, but this clockwise
+        encoder_update_kb(NUMBER_OF_ENCODERS + i, true);
+    }
+    encoder_value[NUMBER_OF_ENCODERS + i] %= ENCODER_RESOLUTION;
+  }
+}
+#endif
diff --git a/quantum/encoder.h b/quantum/encoder.h
index 2024fa303..ec09a8cc4 100644
--- a/quantum/encoder.h
+++ b/quantum/encoder.h
@@ -19,11 +19,13 @@
 
 #include "quantum.h"
 
-#define COUNTRECLOCKWISE 0
-#define CLOCKWISE 1
-
 void encoder_init(void);
 void encoder_read(void);
 
 void encoder_update_kb(int8_t index, bool clockwise);
 void encoder_update_user(int8_t index, bool clockwise);
+
+#ifdef SPLIT_KEYBOARD
+void encoder_state_raw(uint8_t* slave_state);
+void encoder_update_raw(uint8_t* slave_state);
+#endif
diff --git a/quantum/split_common/matrix.c b/quantum/split_common/matrix.c
index dcb96254f..eb110bd23 100644
--- a/quantum/split_common/matrix.c
+++ b/quantum/split_common/matrix.c
@@ -29,6 +29,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "debounce.h"
 #include "transport.h"
 
+#ifdef ENCODER_ENABLE
+  #include "encoder.h"
+#endif
+
 #if (MATRIX_COLS <= 8)
 #  define print_matrix_header() print("\nr/c 01234567\n")
 #  define print_matrix_row(row) print_bin_reverse8(matrix_get_row(row))
@@ -320,6 +324,9 @@ uint8_t matrix_scan(void) {
     matrix_scan_quantum();
   } else {
     transport_slave(matrix + thisHand);
+#ifdef ENCODER_ENABLE
+    encoder_read();
+#endif
     matrix_slave_scan_user();
   }
 
diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index 8d408f6fd..ab055ee65 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -1,4 +1,5 @@
 #include <string.h>
+#include <stddef.h>
 
 #include "config.h"
 #include "matrix.h"
@@ -15,15 +16,45 @@
 extern backlight_config_t backlight_config;
 #endif
 
+#ifdef ENCODER_ENABLE
+#  include "encoder.h"
+#endif
+
 #if defined(USE_I2C) || defined(EH)
 
 #  include "i2c_master.h"
 #  include "i2c_slave.h"
 
-#  define I2C_BACKLIT_START 0x00
-// Need 4 bytes for RGB (32 bit)
-#  define I2C_RGB_START 0x01
-#  define I2C_KEYMAP_START 0x05
+typedef struct __attribute__ ((__packed__)) {
+#ifdef BACKLIGHT_ENABLE
+  uint8_t backlight_level;
+#endif
+#ifdef RGBLIGHT_ENABLE
+  uint32_t rgb_settings;
+#endif
+#ifdef ENCODER_ENABLE
+  uint8_t encoder_state[NUMBER_OF_ENCODERS];
+#endif
+  // Keep matrix last, we are only using this for it's offset
+  uint8_t matrix_start[0];
+} transport_values_t;
+
+__attribute__ ((unused))
+static transport_values_t transport_values;
+
+#ifdef BACKLIGHT_ENABLE
+#  define I2C_BACKLIT_START (uint8_t)offsetof(transport_values_t, backlight_level)
+#endif
+
+#ifdef RGBLIGHT_ENABLE
+#  define I2C_RGB_START (uint8_t)offsetof(transport_values_t, rgb_settings)
+#endif
+
+#ifdef ENCODER_ENABLE
+#  define I2C_ENCODER_START (uint8_t)offsetof(transport_values_t, encoder_state)
+#endif
+
+#define I2C_KEYMAP_START (uint8_t)offsetof(transport_values_t, matrix_start)
 
 #  define TIMEOUT 100
 
@@ -37,25 +68,28 @@ bool transport_master(matrix_row_t matrix[]) {
 
   // write backlight info
 #  ifdef BACKLIGHT_ENABLE
-  static uint8_t prev_level = ~0;
-  uint8_t        level      = get_backlight_level();
-  if (level != prev_level) {
+  uint8_t level = get_backlight_level();
+  if (level != transport_values.backlight_level) {
     if (i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_BACKLIT_START, (void *)&level, sizeof(level), TIMEOUT) >= 0) {
-      prev_level = level;
+      transport_values.backlight_level = level;
     }
   }
 #  endif
 
 #  ifdef RGBLIGHT_ENABLE
-  static uint32_t prev_rgb = ~0;
-  uint32_t        rgb      = rgblight_read_dword();
-  if (rgb != prev_rgb) {
+  uint32_t rgb = rgblight_read_dword();
+  if (rgb != transport_values.rgb_settings) {
     if (i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_RGB_START, (void *)&rgb, sizeof(rgb), TIMEOUT) >= 0) {
-      prev_rgb = rgb;
+      transport_values.rgb_settings = rgb;
     }
   }
 #  endif
 
+#  ifdef ENCODER_ENABLE
+  i2c_readReg(SLAVE_I2C_ADDRESS, I2C_ENCODER_START, (void *)transport_values.encoder_state, sizeof(transport_values.encoder_state), TIMEOUT);
+  encoder_update_raw(&transport_values.encoder_state[0]);
+#  endif
+
   return true;
 }
 
@@ -73,6 +107,10 @@ void transport_slave(matrix_row_t matrix[]) {
   // Update the RGB with the new data
   rgblight_update_dword(rgb);
 #  endif
+
+#  ifdef ENCODER_ENABLE
+  encoder_state_raw((uint8_t*)(i2c_slave_reg + I2C_ENCODER_START));
+#  endif
 }
 
 void transport_master_init(void) { i2c_init(); }
@@ -83,12 +121,15 @@ void transport_slave_init(void) { i2c_slave_init(SLAVE_I2C_ADDRESS); }
 
 #  include "serial.h"
 
-typedef struct _Serial_s2m_buffer_t {
+typedef struct __attribute__ ((__packed__)) {
+#  ifdef ENCODER_ENABLE
+  uint8_t encoder_state[NUMBER_OF_ENCODERS];
+#  endif
   // TODO: if MATRIX_COLS > 8 change to uint8_t packed_matrix[] for pack/unpack
   matrix_row_t smatrix[ROWS_PER_HAND];
 } Serial_s2m_buffer_t;
 
-typedef struct _Serial_m2s_buffer_t {
+typedef struct __attribute__ ((__packed__)) {
 #  ifdef BACKLIGHT_ENABLE
   uint8_t           backlight_level;
 #  endif
@@ -147,6 +188,10 @@ bool transport_master(matrix_row_t matrix[]) {
   }
 #  endif
 
+#  ifdef ENCODER_ENABLE
+  encoder_update_raw((uint8_t*)&serial_s2m_buffer.encoder_state);
+#  endif
+
   return true;
 }
 
@@ -162,6 +207,10 @@ void transport_slave(matrix_row_t matrix[]) {
   // Update RGB config with the new data
   rgblight_update_dword(serial_m2s_buffer.rgblight_config.raw);
 #  endif
+
+#  ifdef ENCODER_ENABLE
+  encoder_state_raw((uint8_t*)&serial_s2m_buffer.encoder_state);
+#  endif
 }
 
 #endif