X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=drivers%2Favr%2Fi2c_master.c;h=a7364bae08f7efe37474dba90c63bea7856f471a;hb=86e0420b42de1797075a88c9b34f0319cea5c1dd;hp=4e76e2e7c60ece674ad49630984c9f365a09b5e3;hpb=9c2dde98e2b963704eb7cb87f6c53c52599fba53;p=qmk_firmware.git

diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c
index 4e76e2e7c..a7364bae0 100755
--- a/drivers/avr/i2c_master.c
+++ b/drivers/avr/i2c_master.c
@@ -7,212 +7,203 @@
 
 #include "i2c_master.h"
 #include "timer.h"
+#include "wait.h"
 
-#define F_SCL 400000UL // SCL frequency
+#ifndef F_SCL
+#  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 */
-	TWBR = (uint8_t)TWBR_val;
+void i2c_init(void) {
+  TWSR = 0; /* no prescaler */
+  TWBR = (uint8_t)TWBR_val;
+
+  #ifdef __AVR_ATmega32A__
+  // set pull-up resistors on I2C bus pins
+  PORTC |= 0b11;
+
+  // enable TWI (two-wire interface)
+  TWCR |= (1 << TWEN);
+
+  // enable TWI interrupt and slave address ACK
+  TWCR |= (1 << TWIE);
+  TWCR |= (1 << TWEA);
+  #endif
 }
 
-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);
+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);
 
   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; }
+  // check if the start condition was successfully transmitted
+  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);
+  // load slave address into data register
+  TWDR = address;
+  // start transmission of address
+  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;
+  // 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;
+  }
 
-	return I2C_STATUS_SUCCESS;
+  return I2C_STATUS_SUCCESS;
 }
 
-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);
+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);
 
   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;
+  return I2C_STATUS_SUCCESS;
 }
 
-int16_t i2c_read_ack(uint16_t timeout)
-{
-
-	// start TWI module and acknowledge data after reception
-	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
+int16_t i2c_read_ack(uint16_t timeout) {
+  // start TWI module and acknowledge data after reception
+  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;
     }
   }
 
-	// return received data from TWDR
-	return TWDR;
+  // return received data from TWDR
+  return TWDR;
 }
 
-int16_t i2c_read_nack(uint16_t timeout)
-{
-
-	// start receiving without acknowledging reception
-	TWCR = (1<<TWINT) | (1<<TWEN);
+int16_t i2c_read_nack(uint16_t timeout) {
+  // start receiving without acknowledging reception
+  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;
     }
   }
 
-	// return received data from TWDR
-	return TWDR;
+  // return received data from TWDR
+  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, const 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++) {
-		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_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 < 0) ? status : I2C_STATUS_SUCCESS;
 }
 
-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, const uint8_t* data, uint16_t length, uint16_t timeout) {
   i2c_status_t status = i2c_start(devaddr | 0x00, timeout);
-	if (status) return status;
+  if (status >= 0) {
+    status = i2c_write(regaddr, timeout);
 
-	status = i2c_write(regaddr, timeout);
-  if (status) return status;
-
-	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;
+  if (status < 0) {
+    goto error;
+  }
 
   status = i2c_start(devaddr | 0x01, timeout);
-	if (status) return status;
 
-	for (uint16_t i = 0; i < (length-1); i++) {
-		status = i2c_read_ack(timeout);
+  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 < 0) ? status : I2C_STATUS_SUCCESS;
 }
 
-i2c_status_t i2c_stop(uint16_t timeout)
-{
-	// 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;
+void i2c_stop(void) {
+  // transmit STOP condition
+  TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
 }