From 983020f84fd7eb567f7eb5378cbe4a86923d026f Mon Sep 17 00:00:00 2001
From: Philipp Claves <pclaves@web.de>
Date: Sun, 6 Nov 2011 00:22:14 +0100
Subject: [PATCH] common/i2c: Support 1 and 2 byte adresses. commin/i2c:
Support bitrate changes (this seems to be broken, needs debugging)
---
common/i2c_common.h | 6 ++--
common/i2c_master.c | 80 ++++++++++++++-------------------------------
common/i2c_master.h | 23 +++++--------
3 files changed, 37 insertions(+), 72 deletions(-)
diff --git a/common/i2c_common.h b/common/i2c_common.h
index 1db1d90..ab7282b 100644
--- a/common/i2c_common.h
+++ b/common/i2c_common.h
@@ -9,9 +9,9 @@
#define I2C_MODE_WRITE 0
//SCL_Freq = F_CPU/(16+2(TWBR)*4**TWPS)
-// #define I2C_BITRATE_REG 92 //20Mhz -> 100kHz I²C
-// #define I2C_BITRATE_REG 17 //20Mhz -> 400kHz I²C
-#define I2C_BITRATE_REG 2 //20Mhz -> 1MHz I²C
+#define I2C_BITRATE_REG_100K 92 //20Mhz -> 100kHz I²C
+#define I2C_BITRATE_REG_400K 17 //20Mhz -> 400kHz I²C
+#define I2C_BITRATE_REG_1M 2 //20Mhz -> 1MHz I²C
#define I2C_PRESCALER 0
#define I2C_STATUS_MASK ((unsigned char)~I2C_PRESCALER) //only need to mask prescaler bits if they are actually present, instead of always masking 0xF8.
diff --git a/common/i2c_master.c b/common/i2c_master.c
index 64764c5..723a51b 100644
--- a/common/i2c_master.c
+++ b/common/i2c_master.c
@@ -3,11 +3,17 @@
#include <util/delay.h>
void i2c_master_init(void){
- TWBR = I2C_BITRATE_REG; //set
+ TWBR = I2C_BITRATE_REG_100K; //set
TWSR = I2C_PRESCALER; //bitrate
TWCR = (1<<TWEN); //enable i2c
}
+void i2c_master_set_speed(uint8_t bitrate){
+// TWCR = 0; //enable i2c
+// TWBR = bitrate;
+// TWCR = (1<<TWEN); //enable i2c
+}
+
void i2c_master_reset(void){ //TODO: Is this really the proper way to reset the i2c contoller?
TWCR = (1 << TWEN) | (1 << TWSTO);
TWCR = (1<<TWINT); //| (1<<TWEN);
@@ -20,7 +26,7 @@ void i2c_master_reset(void){ //TODO: Is this really the proper way to reset the
/**
* Waits for the i2c interface to become ready for the next byte (TWINT is cleared)
*/
-unsigned char i2c_master_wait_ready(void){
+uint8_t i2c_master_wait_ready(void){
uint32_t c = 0;
while (!(TWCR & (1<<TWINT))) {
c++;
@@ -38,7 +44,7 @@ void i2c_master_stop(void){
}
-unsigned char i2c_master_start(unsigned char dest, unsigned char mode){
+uint8_t i2c_master_start(uint8_t dest, uint8_t mode){
TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); //send start signal
if (!i2c_master_wait_ready()) return I2C_ERROR_TIMEOUT+1; //wait until start signal has been sent.
if (((TWSR & I2C_STATUS_MASK) != TW_START) &&
@@ -58,7 +64,7 @@ unsigned char i2c_master_start(unsigned char dest, unsigned char mode){
* @param b byte to send
* @param last if non-zero the byte is expected to be answered by a slave NACK, if zero an ACK is expected.
*/
-unsigned char i2c_master_send_byte(unsigned char b){
+uint8_t i2c_master_send_byte(uint8_t b){
TWDR = b;
TWCR = (1<<TWINT) | (1<<TWEN); //transmit
if (!i2c_master_wait_ready()) return I2C_ERROR_TIMEOUT; //wait until the byte has been sent.
@@ -73,7 +79,7 @@ unsigned char i2c_master_send_byte(unsigned char b){
* @param memory address where to write the byte to.
* @param last if non-zero a NACK will be returned to the sender to signal the end of transmission.
**/
-unsigned char i2c_master_read_byte(unsigned char* b, uint8_t last){
+uint8_t i2c_master_read_byte(uint8_t* b, uint8_t last){
//set ACK/NACK Status //TODO: could this be too late?
TWCR = (1<<TWEN) | (1<<TWINT) | (last ? 0 : (1<<TWEA)); //TODO: Is it a good idea to fiddle with this REG before a read?
@@ -100,8 +106,8 @@ unsigned char i2c_master_read_byte(unsigned char* b, uint8_t last){
* @param length number of bytes to transmit
* @param buffer pointer to the transmit buffer
*/
-unsigned char i2c_master_write(unsigned char dest, unsigned int addr, unsigned char* buffer, unsigned char length){
- unsigned char ret;
+uint8_t i2c_master_write(uint8_t dest, uint16_t addr, uint8_t addr_size, uint8_t* buffer, uint8_t length){
+ uint8_t ret;
i2c_master_last_error_position = 0x01;
@@ -110,15 +116,17 @@ unsigned char i2c_master_write(unsigned char dest, unsigned int addr, unsigned c
i2c_master_last_error_position = 0x02;
- ret = i2c_master_send_byte(addr >> 8);
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
+ if (addr_size >= 2){
+ ret = i2c_master_send_byte(addr >> 8);
+ if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
+ }
ret = i2c_master_send_byte(addr & 0xFF);
if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
i2c_master_last_error_position = 0x03;
- for (unsigned char i = 0; i < length; i++){
+ for (uint8_t i = 0; i < length; i++){
ret = i2c_master_send_byte(buffer[i]);
if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
i2c_master_last_error_position = 0xD0+i;
@@ -129,46 +137,6 @@ unsigned char i2c_master_write(unsigned char dest, unsigned int addr, unsigned c
return I2C_SUCCESS;
}
-/**
- * Writes length bytes to the target. The bytes are obtained by calling the source function for each byte.
- * @param dest i2c address of the target host
- * @param addr register address at the target host
- * @param length number of bytes to transmit
- * @param souzrce pointer to te function returning the bytes to send
- */
-unsigned char i2c_master_write_cut_through(unsigned char dest, unsigned int addr, unsigned char (*source)(void), unsigned char length){
- unsigned char ret;
-
- i2c_master_last_error_position = 0x41;
-
- ret = i2c_master_start(dest, I2C_MODE_WRITE); //send dest address and write mode
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
-
- i2c_master_last_error_position = 0x42;
-
- ret = i2c_master_send_byte(addr >> 8); //send register address (high)
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //error
-
- ret = i2c_master_send_byte(addr & 0xFF); //send register address (low)
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
-
- i2c_master_last_error_position = 0x43;
-
- for (unsigned char i = 0; i < length; i++){
- unsigned char b = source();
- ret = i2c_master_send_byte(b);
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
- i2c_master_last_error_position = 0x50+i;
- }
-
- i2c_master_stop();
-
- TWCR = (1<<TWINT);
-
- return I2C_SUCCESS;
-}
-
-
/**
* Reads bytes from the target into a buffer
* @param dest i2c address of the target host
@@ -176,8 +144,8 @@ unsigned char i2c_master_write_cut_through(unsigned char dest, unsigned int addr
* @param length number of bytes to read
* @param buffer pointer to the receive buffer
*/
-unsigned char i2c_master_read(unsigned char dest, unsigned int addr, unsigned char* buffer, unsigned char length){
- unsigned int ret;
+uint8_t i2c_master_read(uint8_t dest, uint16_t addr, uint8_t addr_size, uint8_t* buffer, uint8_t length){
+ uint16_t ret;
i2c_master_last_error_position = 0x81;
@@ -186,8 +154,10 @@ unsigned char i2c_master_read(unsigned char dest, unsigned int addr, unsigned ch
i2c_master_last_error_position = 0x82;
- ret = i2c_master_send_byte(addr >> 8); //send register address (high)
- if (ret != I2C_SUCCESS) I2C_ERROR(ret); //error
+ if (addr_size >= 2){
+ ret = i2c_master_send_byte(addr >> 8); //send register address (high)
+ if (ret != I2C_SUCCESS) I2C_ERROR(ret); //error
+ }
ret = i2c_master_send_byte(addr & 0xFF); //send register address (low)
if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
@@ -207,7 +177,7 @@ unsigned char i2c_master_read(unsigned char dest, unsigned int addr, unsigned ch
i2c_master_last_error_position = 0x85;
- for (unsigned char i = 0; i < length; i++){
+ for (uint8_t i = 0; i < length; i++){
ret = i2c_master_read_byte(&(buffer[i]), i+1 == length);
if (ret != I2C_SUCCESS) I2C_ERROR(ret); //sends stop and returns the error code
i2c_master_last_error_position = 0x86+i;
diff --git a/common/i2c_master.h b/common/i2c_master.h
index 96f6a6d..3020519 100644
--- a/common/i2c_master.h
+++ b/common/i2c_master.h
@@ -18,39 +18,34 @@
#define I2C_ERROR(ret) {i2c_master_last_error_status = (TWSR & I2C_STATUS_MASK); i2c_master_last_error_control = TWCR; i2c_master_stop(); return (ret);}
-unsigned char i2c_master_last_error_status;
-unsigned char i2c_master_last_error_control;
-unsigned char i2c_master_last_error_position;
+uint8_t i2c_master_last_error_status;
+uint8_t i2c_master_last_error_control;
+uint8_t i2c_master_last_error_position;
void i2c_master_init(void);
+void i2c_master_set_speed(uint8_t bitrate);
+
void i2c_master_reset(void);
/**
* Writes a buffer to a target
* @param dest i2c address of the target host
* @param addr register address at the target host
+ * @param addr_size size of the register address (1 or 2 byte)
* @param length number of bytes to transmit
* @param buffer pointer to the transmit buffer
*/
-unsigned char i2c_master_write(unsigned char dest, unsigned int addr, unsigned char* buffer, unsigned char length);
-
-/**
- * Writes length bytes to the target. The bytes are obtained by calling the source function for each byte.
- * @param dest i2c address of the target host
- * @param addr register address at the target host
- * @param length number of bytes to transmit
- * @param souzrce pointer to te function returning the bytes to send
- */
-unsigned char i2c_master_write_cut_through(unsigned char dest, unsigned int addr, unsigned char (*source)(void), unsigned char length);
+uint8_t i2c_master_write(uint8_t dest, uint16_t addr, uint8_t addr_size, uint8_t* buffer, uint8_t length);
/**
* Reads bytes from the target into a buffer
* @param dest i2c address of the target host
* @param addr register address at the target host
+ * @param addr_size size of the register address (1 or 2 byte)
* @param length number of bytes to read
* @param buffer pointer to the receive buffer
*/
-unsigned char i2c_master_read(unsigned char dest, unsigned int addr, unsigned char* buffer, unsigned char length);
+uint8_t i2c_master_read(uint8_t dest, uint16_t addr, uint8_t addr_size, uint8_t* buffer, uint8_t length);
#endif
\ No newline at end of file
--
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