#include <avr/interrupt.h>
#include <stdio.h>
#include "i2c.h"
+#include "bmc.h"
+#include "ipmb.h"
#define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC);
#define TWCR_NACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC);
#define TWCR_RESET TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC);
+volatile unsigned char i2c_databuf[12];
+volatile uint8_t i2c_len = 0x00;
+static volatile uint8_t i2c_pos = 0x00;
+volatile uint8_t i2c_done = 0x00;
+
void i2c_init()
{
- TWAR = BMC_ADDR;
- TWCR &= ~(1<<TWSTA)|(1<<TWSTO);
- TWCR|= (1<<TWEA) | (1<<TWEN)|(1<<TWIE);
+ TWBR = 0xff;
+ TWAR = BMC_ADDR & 0xfe;
+ TWDR = 0x00;
+ TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
+ TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE));
+ PORTC = 0x03;
}
-ISR (TWI_vect)
+void i2c_send(unsigned char *buf, int len)
{
- printf("Interrupt, Status: %02x!\n", TW_STATUS);
+ uint8_t old_TWCR = TWCR;
+ uint8_t old_SREG = SREG;
+ int i;
+
+ cli();
+
+ TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */
+
+ while(!(TWCR & (1<<TWINT))) {}
+ if ((TW_STATUS & 0xf8) != TW_START)
+ goto out;
+
+ TWDR = buf[0]; /* SLA_W */
+ TWCR = ((1<<TWINT) | (1<<TWEN));
+
+ while(!(TWCR & (1<<TWINT))) {}
+ if ((TW_STATUS & 0xf8) != TW_MT_SLA_ACK)
+ goto out;
+
+ for(i = 1; i < len; i++) {
+ TWDR = buf[i]; /* Send Data */
+ TWCR = ((1<<TWINT) | (1<<TWEN));
+
+ while(!(TWCR & (1<<TWINT))) {}
+ if ((TW_STATUS & 0xf8) != TW_MT_DATA_ACK)
+ goto out;
+ }
+
+ TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
+ while(TWCR & (1<<TWSTO)) {}
+
+#ifdef DEBUG
+ printf("I2C Data sent\n");
+#endif
+
+out:
+ TWDR = 0x00;
+ TWCR = old_TWCR;
+ SREG = old_SREG;
+}
+
+ISR (TWI_vect, ISR_BLOCK)
+{
+ if (i2c_done)
+ TWCR_RESET;
switch (TW_STATUS) {
+ case TW_SR_SLA_ACK:
+#ifdef DEBUG
+ printf("I2C: Slave 0x%02x adressed\n", TWDR);
+#endif
+ i2c_pos = 0x00;
+ i2c_databuf[i2c_pos] = TWDR;
+ i2c_pos++;
+ TWCR_ACK;
+ break;
+
+ case TW_SR_DATA_ACK:
+#ifdef DEBUG
+ printf("I2C: Data received: 0x%02x\n", TWDR);
+#endif
+ i2c_databuf[i2c_pos] = TWDR;
+ i2c_pos++;
+ TWCR_ACK;
+ break;
+
+ case TW_SR_STOP:
+#ifdef DEBUG
+ printf("I2C: STOP received\n");
+#endif
+ i2c_len = i2c_pos;
+ i2c_pos = 0x00;
+ i2c_done = 0x01;
+ TWCR_RESET;
+ break;
+
default:
+ printf("I2C: Unimplemented status 0x%02x\n", TW_STATUS);
TWCR_RESET;
break;
}