Next set of split_common changes (qmk#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

common_features.mk

@@ -308,16 +308,16 @@ ifeq ($(strip $(SPLIT_KEYBOARD)), yes)
     OPT_DEFS += -DSPLIT_KEYBOARD
 
     # Include files used by all split keyboards
-    QUANTUM_SRC += $(QUANTUM_DIR)/split_common/split_flags.c \
-                   $(QUANTUM_DIR)/split_common/split_util.c
+    QUANTUM_SRC += $(QUANTUM_DIR)/split_common/split_util.c
 
     # Determine which (if any) transport files are required
     ifneq ($(strip $(SPLIT_TRANSPORT)), custom)
         QUANTUM_SRC += $(QUANTUM_DIR)/split_common/transport.c
         # Functions added via QUANTUM_LIB_SRC are only included in the final binary if they're called.
-        # Unused functions are pruned away, which is why we can add both drivers here without bloat.
-        QUANTUM_LIB_SRC += $(QUANTUM_DIR)/split_common/i2c.c \
-                           $(QUANTUM_DIR)/split_common/serial.c
+        # Unused functions are pruned away, which is why we can add multiple drivers here without bloat.
+        QUANTUM_LIB_SRC += $(QUANTUM_DIR)/split_common/serial.c \
+                           i2c_master.c \
+                           i2c_slave.c
     endif
     COMMON_VPATH += $(QUANTUM_PATH)/split_common
 endif

docs/i2c_driver.md

@@ -12,7 +12,7 @@ The I2C Master drivers used in QMK have a set of common functions to allow porta
 |`uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                         |Receive data over I2C. Address is the 7-bit slave address without the direction. Saves number of bytes specified by `length` in `data` array. Returns status of transaction. |
 |`uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`       |Same as the `i2c_transmit` function but `regaddr` sets where in the slave the data will be written.                                                                          |
 |`uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`        |Same as the `i2c_receive` function but `regaddr` sets from where in the slave the data will be read.                                                                         |
-|`uint8_t i2c_stop(uint16_t timeout);`                                                                             |Stops the I2C driver.                                                                                                                                                        |
+|`uint8_t i2c_stop(void);`                                                                                         |Ends an I2C transaction.                                                                                                                                                     |
 
 ### Function Return
 

drivers/arm/i2c_master.c

@@ -101,8 +101,7 @@ uint8_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t l
   return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), regaddr, 1, data, length, MS2ST(timeout));
 }
 
-// This is usually not needed. It releases the driver to allow pins to become GPIO again.
-uint8_t i2c_stop(uint16_t timeout)
+uint8_t i2c_stop(void)
 {
   i2cStop(&I2C_DRIVER);
   return 0;

drivers/arm/i2c_master.h

@@ -47,4 +47,4 @@ uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t ti
 uint8_t i2c_transmit_receive(uint8_t address, uint8_t * tx_body, uint16_t tx_length, uint8_t * rx_body, uint16_t rx_length);
 uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);
 uint8_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t length, uint16_t timeout);
-uint8_t i2c_stop(uint16_t timeout);
+uint8_t i2c_stop(void);

drivers/avr/i2c_master.c

@@ -7,82 +7,84 @@
 
 #include "i2c_master.h"
 #include "timer.h"
+#include "wait.h"
 
 #ifndef F_SCL
-#define F_SCL 400000UL // SCL frequency
+#  define F_SCL 400000UL  // SCL frequency
 #endif
 #define Prescaler 1
-#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16 ) / 2)
+#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16) / 2)
 
-void i2c_init(void)
-{
-  TWSR = 0;     /* no prescaler */
+void i2c_init(void) {
+  TWSR = 0; /* no prescaler */
   TWBR = (uint8_t)TWBR_val;
 }
 
-i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
-{
+i2c_status_t i2c_start(uint8_t address, uint16_t timeout) {
   // reset TWI control register
   TWCR = 0;
   // transmit START condition
-  TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
 
   // check if the start condition was successfully transmitted
-  if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return I2C_STATUS_ERROR; }
+  if (((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)) {
+    return I2C_STATUS_ERROR;
+  }
 
   // load slave address into data register
   TWDR = address;
   // start transmission of address
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
 
   // check if the device has acknowledged the READ / WRITE mode
   uint8_t twst = TW_STATUS & 0xF8;
-  if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return I2C_STATUS_ERROR;
+  if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
+    return I2C_STATUS_ERROR;
+  }
 
   return I2C_STATUS_SUCCESS;
 }
 
-i2c_status_t i2c_write(uint8_t data, uint16_t timeout)
-{
+i2c_status_t i2c_write(uint8_t data, uint16_t timeout) {
   // load data into data register
   TWDR = data;
   // start transmission of data
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
 
-  if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; }
+  if ((TW_STATUS & 0xF8) != TW_MT_DATA_ACK) {
+    return I2C_STATUS_ERROR;
+  }
 
   return I2C_STATUS_SUCCESS;
 }
 
-int16_t i2c_read_ack(uint16_t timeout)
-{
-
+int16_t i2c_read_ack(uint16_t timeout) {
   // start TWI module and acknowledge data after reception
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
+  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
@@ -92,14 +94,12 @@ int16_t i2c_read_ack(uint16_t timeout)
   return TWDR;
 }
 
-int16_t i2c_read_nack(uint16_t timeout)
-{
-
+int16_t i2c_read_nack(uint16_t timeout) {
   // start receiving without acknowledging reception
-  TWCR = (1<<TWINT) | (1<<TWEN);
+  TWCR = (1 << TWINT) | (1 << TWEN);
 
   uint16_t timeout_timer = timer_read();
-  while( !(TWCR & (1<<TWINT)) ) {
+  while (!(TWCR & (1 << TWINT))) {
     if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
@@ -109,115 +109,89 @@ int16_t i2c_read_nack(uint16_t timeout)
   return TWDR;
 }
 
-i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(address | I2C_WRITE, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < length; i++) {
+  for (uint16_t i = 0; i < length && status >= 0; i++) {
     status = i2c_write(data[i], timeout);
-    if (status) return status;
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return status;
 }
 
-i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(address | I2C_READ, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < (length-1); i++) {
+  for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) {
     status = i2c_read_ack(timeout);
     if (status >= 0) {
       data[i] = status;
-    } else {
-      return status;
     }
   }
 
-  status = i2c_read_nack(timeout);
-  if (status >= 0 ) {
-    data[(length-1)] = status;
-  } else {
-    return status;
+  if (status >= 0) {
+    status = i2c_read_nack(timeout);
+    if (status >= 0) {
+      data[(length - 1)] = status;
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return status;
 }
 
-i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
-{
+i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(devaddr | 0x00, timeout);
-  if (status) return status;
-
-  status = i2c_write(regaddr, timeout);
-  if (status) return status;
+  if (status >= 0) {
+    status = i2c_write(regaddr, timeout);
 
-  for (uint16_t i = 0; i < length; i++) {
-    status = i2c_write(data[i], timeout);
-    if (status) return status;
+    for (uint16_t i = 0; i < length && status >= 0; i++) {
+      status = i2c_write(data[i], timeout);
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return 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_status_t status = i2c_start(devaddr, timeout);
-  if (status) return status;
+  if (status < 0) {
+    goto error;
+  }
 
   status = i2c_write(regaddr, timeout);
-  if (status) return status;
-
-  status = i2c_stop(timeout);
-  if (status) return status;
+  if (status < 0) {
+    goto error;
+  }
 
   status = i2c_start(devaddr | 0x01, timeout);
-  if (status) return status;
 
-  for (uint16_t i = 0; i < (length-1); i++) {
+  for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) {
     status = i2c_read_ack(timeout);
     if (status >= 0) {
       data[i] = status;
-    } else {
-      return status;
     }
   }
 
-  status = i2c_read_nack(timeout);
-  if (status >= 0 ) {
-    data[(length-1)] = status;
-  } else {
-    return status;
+  if (status >= 0) {
+    status = i2c_read_nack(timeout);
+    if (status >= 0) {
+      data[(length - 1)] = status;
+    }
   }
 
-  status = i2c_stop(timeout);
-  if (status) return status;
+error:
+  i2c_stop();
 
-  return I2C_STATUS_SUCCESS;
+  return status;
 }
 
-i2c_status_t i2c_stop(uint16_t timeout)
-{
+void i2c_stop(void) {
   // transmit STOP condition
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
-
-  uint16_t timeout_timer = timer_read();
-  while(TWCR & (1<<TWSTO)) {
-    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
-      return I2C_STATUS_TIMEOUT;
-    }
-  }
-
-  return I2C_STATUS_SUCCESS;
+  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
 }

drivers/avr/i2c_master.h

@@ -26,6 +26,6 @@ i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint1
 i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);
 i2c_status_t i2c_writeReg(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_status_t i2c_stop(uint16_t timeout);
+void i2c_stop(void);
 
 #endif // I2C_MASTER_H

drivers/avr/i2c_slave.c

@@ -16,7 +16,7 @@ static volatile bool slave_has_register_set = false;
 
 void i2c_slave_init(uint8_t address){
     // load address into TWI address register
-    TWAR = (address << 1);
+    TWAR = address;
     // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt
     TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN);
 }

keyboards/cannonkeys/satisfaction75/i2c_master.c

@@ -109,7 +109,7 @@ uint8_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t l
 }
 
 // This is usually not needed. It releases the driver to allow pins to become GPIO again.
-uint8_t i2c_stop(uint16_t timeout)
+uint8_t i2c_stop(void)
 {
   i2cStop(&I2C_DRIVER);
   return 0;

keyboards/dc01/left/matrix.c

@@ -455,10 +455,10 @@ i2c_status_t i2c_transaction(uint8_t address, uint32_t mask, uint8_t col_offset)
         matrix[MATRIX_ROWS - 1] |= ((uint32_t)err << (MATRIX_COLS_SCANNED + col_offset)); //add new bits at the end
 
     } else {
-        i2c_stop(10);
+        i2c_stop();
         return 1;
     }
 
-    i2c_stop(10);
+    i2c_stop();
     return 0;
 }

keyboards/ergodox_ez/ergodox_ez.c

@@ -128,7 +128,7 @@ uint8_t init_mcp23018(void) {
     mcp23018_status = i2c_write(IODIRA, ERGODOX_EZ_I2C_TIMEOUT);            if (mcp23018_status) goto out;
     mcp23018_status = i2c_write(0b00000000, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
     mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
+    i2c_stop();
 
     // set pull-up
     // - unused  : on  : 1
@@ -140,7 +140,7 @@ uint8_t init_mcp23018(void) {
     mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
 
 out:
-    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
+    i2c_stop();
 
 #ifdef LEFT_LEDS
     if (!mcp23018_status) mcp23018_status = ergodox_left_leds_update();
@@ -179,7 +179,7 @@ uint8_t ergodox_left_leds_update(void) {
     if (mcp23018_status) goto out;
 
  out:
-    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
+    i2c_stop();
     return mcp23018_status;
 }
 #endif