Next set of split_common changes (#4974)

* Update split_common to use standard i2c drivers

* Eliminate RGB_DIRTY/BACKLIT_DIRTY

* Fix avr i2c_master error handling

* Fix i2c_slave addressing

* Remove unneeded timeout on i2c_stop()

* Fix RGB I2C transfers

* Remove incorrect comment

7 files changed, 85 insertions, 420 deletions

diff --git a/quantum/split_common/i2c.c b/quantum/split_common/i2c.c
deleted file mode 100644
index 45e958b39..000000000
--- a/quantum/split_common/i2c.c
+++ /dev/null
@@ -1,184 +0,0 @@
-#include <util/twi.h>
-#include <avr/io.h>
-#include <stdlib.h>
-#include <avr/interrupt.h>
-#include <util/twi.h>
-#include <stdbool.h>
-#include "i2c.h"
-#include "split_flags.h"
-
-// Limits the amount of we wait for any one i2c transaction.
-// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is
-// 9 bits, a single transaction will take around 90μs to complete.
-//
-// (F_CPU/SCL_CLOCK)  =>  # of μC cycles to transfer a bit
-// poll loop takes at least 8 clock cycles to execute
-#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8
-
-#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE)
-
-volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
-
-static volatile uint8_t slave_buffer_pos;
-static volatile bool slave_has_register_set = false;
-
-// Wait for an i2c operation to finish
-inline static
-void i2c_delay(void) {
-  uint16_t lim = 0;
-  while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT)
-    lim++;
-
-  // easier way, but will wait slightly longer
-  // _delay_us(100);
-}
-
-// Setup twi to run at 100kHz
-void i2c_master_init(void) {
-  // no prescaler
-  TWSR = 0;
-  // Set TWI clock frequency to SCL_CLOCK. Need TWBR>10.
-  // Check datasheets for more info.
-  TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
-}
-
-// Start a transaction with the given i2c slave address. The direction of the
-// transfer is set with I2C_READ and I2C_WRITE.
-// returns: 0 => success
-//          1 => error
-uint8_t i2c_master_start(uint8_t address) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
-
-  i2c_delay();
-
-  // check that we started successfully
-  if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START))
-    return 1;
-
-  TWDR = address;
-  TWCR = (1<<TWINT) | (1<<TWEN);
-
-  i2c_delay();
-
-  if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) )
-    return 1; // slave did not acknowledge
-  else
-    return 0; // success
-}
-
-
-// Finish the i2c transaction.
-void i2c_master_stop(void) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
-
-  uint16_t lim = 0;
-  while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT)
-    lim++;
-}
-
-// Write one byte to the i2c slave.
-// returns 0 => slave ACK
-//         1 => slave NACK
-uint8_t i2c_master_write(uint8_t data) {
-  TWDR = data;
-  TWCR = (1<<TWINT) | (1<<TWEN);
-
-  i2c_delay();
-
-  // check if the slave acknowledged us
-  return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1;
-}
-
-uint8_t i2c_master_write_data(void *const TXdata, uint8_t dataLen) {
-    
-    uint8_t *data = (uint8_t *)TXdata;
-    int err = 0;
-    
-    for (int i = 0; i < dataLen; i++) {
-        err = i2c_master_write(data[i]);
-        
-        if ( err )
-            return err;
-    }
-    
-    return err;
-    
-}
-
-// Read one byte from the i2c slave. If ack=1 the slave is acknowledged,
-// if ack=0 the acknowledge bit is not set.
-// returns: byte read from i2c device
-uint8_t i2c_master_read(int ack) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA);
-
-  i2c_delay();
-  return TWDR;
-}
-
-void i2c_reset_state(void) {
-  TWCR = 0;
-}
-
-void i2c_slave_init(uint8_t address) {
-  TWAR = address << 0; // slave i2c address
-  // TWEN  - twi enable
-  // TWEA  - enable address acknowledgement
-  // TWINT - twi interrupt flag
-  // TWIE  - enable the twi interrupt
-  TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN);
-}
-
-ISR(TWI_vect);
-
-ISR(TWI_vect) {
-  uint8_t ack = 1;
-  switch(TW_STATUS) {
-    case TW_SR_SLA_ACK:
-      // this device has been addressed as a slave receiver
-      slave_has_register_set = false;
-      break;
-
-    case TW_SR_DATA_ACK:
-      // this device has received data as a slave receiver
-      // The first byte that we receive in this transaction sets the location
-      // of the read/write location of the slaves memory that it exposes over
-      // i2c.  After that, bytes will be written at slave_buffer_pos, incrementing
-      // slave_buffer_pos after each write.
-      if(!slave_has_register_set) {
-        slave_buffer_pos = TWDR;
-        // don't acknowledge the master if this memory loctaion is out of bounds
-        if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) {
-          ack = 0;
-          slave_buffer_pos = 0;
-        }  
-        
-        slave_has_register_set = true;
-      } else {      
-        i2c_slave_buffer[slave_buffer_pos] = TWDR;
-        
-        if ( slave_buffer_pos == I2C_BACKLIT_START) {
-            BACKLIT_DIRTY = true;
-        } else if ( slave_buffer_pos == (I2C_RGB_START+3)) {
-            RGB_DIRTY = true;
-        }
-        
-        BUFFER_POS_INC();
-      }
-      break;
-
-    case TW_ST_SLA_ACK:
-    case TW_ST_DATA_ACK:
-      // master has addressed this device as a slave transmitter and is
-      // requesting data.
-      TWDR = i2c_slave_buffer[slave_buffer_pos];
-      BUFFER_POS_INC();
-      break;
-
-    case TW_BUS_ERROR: // something went wrong, reset twi state
-      TWCR = 0;
-    default:
-      break;
-  }
-  // Reset everything, so we are ready for the next TWI interrupt
-  TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
-}
diff --git a/quantum/split_common/i2c.h b/quantum/split_common/i2c.h
deleted file mode 100644
index 91e8e96f4..000000000
--- a/quantum/split_common/i2c.h
+++ /dev/null
@@ -1,59 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-#ifndef F_CPU
-#define F_CPU 16000000UL
-#endif
-
-#define I2C_READ 1
-#define I2C_WRITE 0
-
-#define I2C_ACK 1
-#define I2C_NACK 0
-
-// Address location defines (Keymap should be last, as it's size is dynamic)
-#define I2C_BACKLIT_START   0x00
-// Need 4 bytes for RGB (32 bit)
-#define I2C_RGB_START       0x01
-#define I2C_KEYMAP_START    0x06
-
-// Slave buffer (8bit per)
-// Rows per hand + backlit space + rgb space
-// TODO : Make this dynamically sized
-#define SLAVE_BUFFER_SIZE 0x20
-
-// i2c SCL clock frequency
-#ifndef SCL_CLOCK
-#define SCL_CLOCK  100000L
-#endif
-
-// Support 8bits right now (8 cols) will need to edit to take higher (code exists in delta split?)
-extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
-
-void i2c_master_init(void);
-uint8_t i2c_master_start(uint8_t address);
-void i2c_master_stop(void);
-uint8_t i2c_master_write(uint8_t data);
-uint8_t i2c_master_write_data(void *const TXdata, uint8_t dataLen);
-uint8_t i2c_master_read(int);
-void i2c_reset_state(void);
-void i2c_slave_init(uint8_t address);
-
-
-static inline unsigned char i2c_start_read(unsigned char addr) {
-  return i2c_master_start((addr << 1) | I2C_READ);
-}
-
-static inline unsigned char i2c_start_write(unsigned char addr) {
-  return i2c_master_start((addr << 1) | I2C_WRITE);
-}
-
-// from SSD1306 scrips
-extern unsigned char i2c_rep_start(unsigned char addr);
-extern void i2c_start_wait(unsigned char addr);
-extern unsigned char i2c_readAck(void);
-extern unsigned char i2c_readNak(void);
-extern unsigned char i2c_read(unsigned char ack);
-
-#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
diff --git a/quantum/split_common/matrix.c b/quantum/split_common/matrix.c
index f2a277c69..dcb96254f 100644
--- a/quantum/split_common/matrix.c
+++ b/quantum/split_common/matrix.c
@@ -25,7 +25,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "matrix.h"
 #include "split_util.h"
 #include "config.h"
-#include "split_flags.h"
 #include "quantum.h"
 #include "debounce.h"
 #include "transport.h"
diff --git a/quantum/split_common/split_flags.c b/quantum/split_common/split_flags.c
deleted file mode 100644
index 1f5825d65..000000000
--- a/quantum/split_common/split_flags.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#include "split_flags.h"
-
-volatile bool RGB_DIRTY = false;
-
-volatile bool BACKLIT_DIRTY = false;
\ No newline at end of file
diff --git a/quantum/split_common/split_flags.h b/quantum/split_common/split_flags.h
deleted file mode 100644
index aaac474a7..000000000
--- a/quantum/split_common/split_flags.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#pragma once
-
-#include <stdbool.h>
-#include <stdint.h>
-
-/**
-* Global Flags
-**/
-
-//RGB Stuff
-extern volatile bool RGB_DIRTY;
-
-
-//Backlight Stuff
-extern volatile bool BACKLIT_DIRTY;
diff --git a/quantum/split_common/split_util.c b/quantum/split_common/split_util.c
index 5095cb8fd..da870f877 100644
--- a/quantum/split_common/split_util.c
+++ b/quantum/split_common/split_util.c
@@ -3,7 +3,6 @@
 #include "keyboard.h"
 #include "config.h"
 #include "timer.h"
-#include "split_flags.h"
 #include "transport.h"
 #include "quantum.h"
 
@@ -60,10 +59,6 @@ static void keyboard_master_setup(void) {
   #endif
 #endif
   transport_master_init();
-
-  // For master the Backlight info needs to be sent on startup
-  // Otherwise the salve won't start with the proper info until an update
-  BACKLIT_DIRTY = true;
 }
 
 static void keyboard_slave_setup(void)
diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index 95738530e..b16852bc1 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -3,146 +3,83 @@
 #include "matrix.h"
 #include "quantum.h"
 
-#define ROWS_PER_HAND (MATRIX_ROWS/2)
+#define ROWS_PER_HAND (MATRIX_ROWS / 2)
 
 #ifdef RGBLIGHT_ENABLE
-#   include "rgblight.h"
+#  include "rgblight.h"
 #endif
 
 #ifdef BACKLIGHT_ENABLE
-# include "backlight.h"
-  extern backlight_config_t backlight_config;
+#  include "backlight.h"
+extern backlight_config_t backlight_config;
 #endif
 
 #if defined(USE_I2C) || defined(EH)
 
-#include "i2c.h"
+#  include "i2c_master.h"
+#  include "i2c_slave.h"
 
-#ifndef SLAVE_I2C_ADDRESS
-#  define SLAVE_I2C_ADDRESS           0x32
-#endif
+#  define I2C_BACKLIT_START 0x00
+// Need 4 bytes for RGB (32 bit)
+#  define I2C_RGB_START 0x01
+#  define I2C_KEYMAP_START 0x05
 
-#if (MATRIX_COLS > 8)
-#  error "Currently only supports 8 COLS"
-#endif
+#  define TIMEOUT 100
+
+#  ifndef SLAVE_I2C_ADDRESS
+#    define SLAVE_I2C_ADDRESS 0x32
+#  endif
 
 // Get rows from other half over i2c
 bool transport_master(matrix_row_t matrix[]) {
-  int err = 0;
+  i2c_readReg(SLAVE_I2C_ADDRESS, I2C_KEYMAP_START, (void *)matrix, ROWS_PER_HAND * sizeof(matrix_row_t), TIMEOUT);
 
   // write backlight info
-#ifdef BACKLIGHT_ENABLE
-  if (BACKLIT_DIRTY) {
-    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-    if (err) { goto i2c_error; }
-
-    // Backlight location
-    err = i2c_master_write(I2C_BACKLIT_START);
-    if (err) { goto i2c_error; }
-
-    // Write backlight
-    i2c_master_write(get_backlight_level());
-
-    BACKLIT_DIRTY = false;
-  }
-#endif
-
-  err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-  if (err) { goto i2c_error; }
-
-  // start of matrix stored at I2C_KEYMAP_START
-  err = i2c_master_write(I2C_KEYMAP_START);
-  if (err) { goto i2c_error; }
-
-  // Start read
-  err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_READ);
-  if (err) { goto i2c_error; }
-
-  if (!err) {
-    int i;
-    for (i = 0; i < ROWS_PER_HAND-1; ++i) {
-      matrix[i] = i2c_master_read(I2C_ACK);
-    }
-    matrix[i] = i2c_master_read(I2C_NACK);
-    i2c_master_stop();
-  } else {
-i2c_error: // the cable is disconnceted, or something else went wrong
-    i2c_reset_state();
-    return false;
+#  ifdef BACKLIGHT_ENABLE
+  static uint8_t prev_level = ~0;
+  uint8_t        level      = get_backlight_level();
+  if (level != prev_level) {
+    i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_BACKLIT_START, (void *)&level, sizeof(level), TIMEOUT);
+    prev_level = level;
   }
-
-#ifdef RGBLIGHT_ENABLE
-  if (RGB_DIRTY) {
-    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-    if (err) { goto i2c_error; }
-
-    // RGB Location
-    err = i2c_master_write(I2C_RGB_START);
-    if (err) { goto i2c_error; }
-
-    uint32_t dword = eeconfig_read_rgblight();
-
-    // Write RGB
-    err = i2c_master_write_data(&dword, 4);
-    if (err) { goto i2c_error; }
-
-    RGB_DIRTY = false;
-    i2c_master_stop();
+#  endif
+
+#  ifdef RGBLIGHT_ENABLE
+  static uint32_t prev_rgb = ~0;
+  uint32_t        rgb      = eeconfig_read_rgblight();
+  if (rgb != prev_rgb) {
+    i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_RGB_START, (void *)&rgb, sizeof(rgb), TIMEOUT);
+    prev_rgb = rgb;
   }
-#endif
+#  endif
 
   return true;
 }
 
 void transport_slave(matrix_row_t matrix[]) {
-
-  for (int i = 0; i < ROWS_PER_HAND; ++i)
-  {
-    i2c_slave_buffer[I2C_KEYMAP_START + i] = matrix[i];
-  }
-  // Read Backlight Info
-  #ifdef BACKLIGHT_ENABLE
-  if (BACKLIT_DIRTY)
-  {
-    backlight_set(i2c_slave_buffer[I2C_BACKLIT_START]);
-    BACKLIT_DIRTY = false;
+  for (int i = 0; i < ROWS_PER_HAND * sizeof(matrix_row_t); ++i) {
+    i2c_slave_reg[I2C_KEYMAP_START + i] = matrix[i];
   }
-  #endif
-  #ifdef RGBLIGHT_ENABLE
-  if (RGB_DIRTY)
-  {
-    // Disable interupts (RGB data is big)
-    cli();
-    // Create new DWORD for RGB data
-    uint32_t dword;
-
-    // Fill the new DWORD with the data that was sent over
-    uint8_t * dword_dat = (uint8_t *)(&dword);
-    for (int i = 0; i < 4; i++)
-    {
-      dword_dat[i] = i2c_slave_buffer[I2C_RGB_START + i];
-    }
-
-    // Update the RGB now with the new data and set RGB_DIRTY to false
-    rgblight_update_dword(dword);
-    RGB_DIRTY = false;
-    // Re-enable interupts now that RGB is set
-    sei();
-  }
-  #endif
-}
 
-void transport_master_init(void) {
-  i2c_master_init();
-}
+// Read Backlight Info
+#  ifdef BACKLIGHT_ENABLE
+  backlight_set(i2c_slave_reg[I2C_BACKLIT_START]);
+#  endif
 
-void transport_slave_init(void) {
-  i2c_slave_init(SLAVE_I2C_ADDRESS);
+#  ifdef RGBLIGHT_ENABLE
+  uint32_t rgb = *(uint32_t *)(i2c_slave_reg + I2C_RGB_START);
+  // Update the RGB with the new data
+  rgblight_update_dword(rgb);
+#  endif
 }
 
-#else // USE_SERIAL
+void transport_master_init(void) { i2c_init(); }
+
+void transport_slave_init(void) { i2c_slave_init(SLAVE_I2C_ADDRESS); }
 
-#include "serial.h"
+#else  // USE_SERIAL
+
+#  include "serial.h"
 
 typedef struct _Serial_s2m_buffer_t {
   // TODO: if MATRIX_COLS > 8 change to uint8_t packed_matrix[] for pack/unpack
@@ -150,40 +87,40 @@ typedef struct _Serial_s2m_buffer_t {
 } Serial_s2m_buffer_t;
 
 typedef struct _Serial_m2s_buffer_t {
-#ifdef BACKLIGHT_ENABLE
-    uint8_t backlight_level;
-#endif
-#if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
-    rgblight_config_t rgblight_config; //not yet use
-    //
-    // When MCUs on both sides drive their respective RGB LED chains,
-    // it is necessary to synchronize, so it is necessary to communicate RGB information.
-    // In that case, define the RGBLIGHT_SPLIT macro.
-    //
-    // Otherwise, if the master side MCU drives both sides RGB LED chains,
-    // there is no need to communicate.
-#endif
+#  ifdef BACKLIGHT_ENABLE
+  uint8_t           backlight_level;
+#  endif
+#  if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
+  rgblight_config_t rgblight_config;  // not yet use
+  //
+  // When MCUs on both sides drive their respective RGB LED chains,
+  // it is necessary to synchronize, so it is necessary to communicate RGB
+  // information. In that case, define the RGBLIGHT_SPLIT macro.
+  //
+  // Otherwise, if the master side MCU drives both sides RGB LED chains,
+  // there is no need to communicate.
+#  endif
 } Serial_m2s_buffer_t;
 
 volatile Serial_s2m_buffer_t serial_s2m_buffer = {};
 volatile Serial_m2s_buffer_t serial_m2s_buffer = {};
-uint8_t volatile status0 = 0;
+uint8_t volatile status0                       = 0;
 
 SSTD_t transactions[] = {
-  { (uint8_t *)&status0,
-    sizeof(serial_m2s_buffer), (uint8_t *)&serial_m2s_buffer,
-    sizeof(serial_s2m_buffer), (uint8_t *)&serial_s2m_buffer
-  }
+    {
+        (uint8_t *)&status0,
+        sizeof(serial_m2s_buffer),
+        (uint8_t *)&serial_m2s_buffer,
+        sizeof(serial_s2m_buffer),
+        (uint8_t *)&serial_s2m_buffer,
+    },
 };
 
-void transport_master_init(void)
-{ soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); }
+void transport_master_init(void) { soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); }
 
-void transport_slave_init(void)
-{ soft_serial_target_init(transactions, TID_LIMIT(transactions)); }
+void transport_slave_init(void) { soft_serial_target_init(transactions, TID_LIMIT(transactions)); }
 
 bool transport_master(matrix_row_t matrix[]) {
-
   if (soft_serial_transaction()) {
     return false;
   }
@@ -193,32 +130,29 @@ bool transport_master(matrix_row_t matrix[]) {
     matrix[i] = serial_s2m_buffer.smatrix[i];
   }
 
-  #if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
-    // Code to send RGB over serial goes here (not implemented yet)
-  #endif
+#  if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
+  // Code to send RGB over serial goes here (not implemented yet)
+#  endif
 
-  #ifdef BACKLIGHT_ENABLE
-    // Write backlight level for slave to read
-    serial_m2s_buffer.backlight_level = backlight_config.enable ? backlight_config.level : 0;
-  #endif
+#  ifdef BACKLIGHT_ENABLE
+  // Write backlight level for slave to read
+  serial_m2s_buffer.backlight_level = backlight_config.enable ? backlight_config.level : 0;
+#  endif
 
   return true;
 }
 
 void transport_slave(matrix_row_t matrix[]) {
-
   // TODO: if MATRIX_COLS > 8 change to pack()
-  for (int i = 0; i < ROWS_PER_HAND; ++i)
-  {
+  for (int i = 0; i < ROWS_PER_HAND; ++i) {
     serial_s2m_buffer.smatrix[i] = matrix[i];
   }
-  #ifdef BACKLIGHT_ENABLE
-    backlight_set(serial_m2s_buffer.backlight_level);
-  #endif
-  #if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
-  // Add serial implementation for RGB here
-  #endif
-
+#  ifdef BACKLIGHT_ENABLE
+  backlight_set(serial_m2s_buffer.backlight_level);
+#  endif
+#  if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
+// Add serial implementation for RGB here
+#  endif
 }
 
 #endif