X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=drivers%2Favr%2Fi2c_master.c;h=4e76e2e7c60ece674ad49630984c9f365a09b5e3;hb=08283f61244479743c4ff5ecba39bd0264979d77;hp=f4a4bb7b0be474e9d486e5382d94042778ac2606;hpb=a98a91cf1b923107e9f26df316c1ef2192ff14f7;p=qmk_firmware.git

diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c
index f4a4bb7b0..4e76e2e7c 100755
--- a/drivers/avr/i2c_master.c
+++ b/drivers/avr/i2c_master.c
@@ -6,6 +6,7 @@
 #include <util/twi.h>
 
 #include "i2c_master.h"
+#include "timer.h"
 
 #define F_SCL 400000UL // SCL frequency
 #define Prescaler 1
@@ -13,137 +14,205 @@
 
 void i2c_init(void)
 {
+  TWSR = 0;     /* no prescaler */
 	TWBR = (uint8_t)TWBR_val;
 }
 
-uint8_t i2c_start(uint8_t address)
+i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
 {
 	// reset TWI control register
 	TWCR = 0;
-	// transmit START condition 
+	// transmit START condition
 	TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
-	// wait for end of transmission
-	while( !(TWCR & (1<<TWINT)) );
-	
+
+  uint16_t timeout_timer = timer_read();
+  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((TWSR & 0xF8) != TW_START){ return 1; }
-	
+	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);
-	// wait for end of transmission
-	while( !(TWCR & (1<<TWINT)) );
-	
+
+  timeout_timer = timer_read();
+  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 1;
-	
-	return 0;
+	if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return I2C_STATUS_ERROR;
+
+	return I2C_STATUS_SUCCESS;
 }
 
-uint8_t i2c_write(uint8_t data)
+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);
-	// wait for end of transmission
-	while( !(TWCR & (1<<TWINT)) );
-	
-	if( (TWSR & 0xF8) != TW_MT_DATA_ACK ){ return 1; }
-	
-	return 0;
+
+  uint16_t timeout_timer = timer_read();
+  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; }
+
+	return I2C_STATUS_SUCCESS;
 }
 
-uint8_t i2c_read_ack(void)
+int16_t i2c_read_ack(uint16_t timeout)
 {
-	
+
 	// start TWI module and acknowledge data after reception
-	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); 
-	// wait for end of transmission
-	while( !(TWCR & (1<<TWINT)) );
+	TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
+
+  uint16_t timeout_timer = timer_read();
+  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;
 }
 
-uint8_t i2c_read_nack(void)
+int16_t i2c_read_nack(uint16_t timeout)
 {
-	
+
 	// start receiving without acknowledging reception
 	TWCR = (1<<TWINT) | (1<<TWEN);
-	// wait for end of transmission
-	while( !(TWCR & (1<<TWINT)) );
+
+  uint16_t timeout_timer = timer_read();
+  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;
 }
 
-uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length)
+i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
 {
-	if (i2c_start(address | I2C_WRITE)) return 1;
-	
-	for (uint16_t i = 0; i < length; i++)
-	{
-		if (i2c_write(data[i])) return 1;
+  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;
 	}
-	
-	i2c_stop();
-	
-	return 0;
+
+	status = i2c_stop(timeout);
+  if (status) return status;
+
+	return I2C_STATUS_SUCCESS;
 }
 
-uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length)
+i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
 {
-	if (i2c_start(address | I2C_READ)) return 1;
-	
-	for (uint16_t i = 0; i < (length-1); i++)
-	{
-		data[i] = i2c_read_ack();
+  i2c_status_t status = i2c_start(address | I2C_READ, timeout);
+	if (status) return status;
+
+	for (uint16_t i = 0; i < (length-1); i++) {
+    status = i2c_read_ack(timeout);
+    if (status >= 0) {
+      data[i] = status;
+    } else {
+      return status;
+    }
 	}
-	data[(length-1)] = i2c_read_nack();
-	
-	i2c_stop();
-	
-	return 0;
+
+  status = i2c_read_nack(timeout);
+  if (status >= 0 ) {
+    data[(length-1)] = status;
+  } else {
+    return status;
+  }
+
+  status = i2c_stop(timeout);
+  if (status) return status;
+
+	return I2C_STATUS_SUCCESS;
 }
 
-uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length)
+i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
 {
-	if (i2c_start(devaddr | 0x00)) return 1;
+  i2c_status_t status = i2c_start(devaddr | 0x00, timeout);
+	if (status) return status;
 
-	i2c_write(regaddr);
+	status = i2c_write(regaddr, timeout);
+  if (status) return status;
 
-	for (uint16_t i = 0; i < length; i++)
-	{
-		if (i2c_write(data[i])) return 1;
+	for (uint16_t i = 0; i < length; i++) {
+    status = i2c_write(data[i], timeout);
+		if (status) return status;
 	}
 
-	i2c_stop();
+	status = i2c_stop(timeout);
+  if (status) return status;
 
-	return 0;
+	return I2C_STATUS_SUCCESS;
 }
 
-uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length)
+i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
 {
-	if (i2c_start(devaddr)) return 1;
-
-	i2c_write(regaddr);
-
-	if (i2c_start(devaddr | 0x01)) return 1;
-
-	for (uint16_t i = 0; i < (length-1); i++)
-	{
-		data[i] = i2c_read_ack();
+  i2c_status_t status = i2c_start(devaddr, timeout);
+	if (status) return status;
+
+  status = i2c_write(regaddr, timeout);
+  if (status) return status;
+
+  status = i2c_start(devaddr | 0x01, timeout);
+	if (status) return status;
+
+	for (uint16_t i = 0; i < (length-1); i++) {
+		status = i2c_read_ack(timeout);
+    if (status >= 0) {
+      data[i] = status;
+    } else {
+      return status;
+    }
 	}
-	data[(length-1)] = i2c_read_nack();
 
-	i2c_stop();
+  status = i2c_read_nack(timeout);
+  if (status >= 0 ) {
+    data[(length-1)] = status;
+  } else {
+    return status;
+  }
 
-	return 0;
+  status = i2c_stop(timeout);
+  if (status) return status;
+
+	return I2C_STATUS_SUCCESS;
 }
 
-void i2c_stop(void)
+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;
 }