#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);
-static volatile unsigned char databuf[12];
-static volatile uint8_t pos = 0x00;
+volatile unsigned char i2c_databuf[24];
+volatile uint8_t i2c_len = 0x00;
+static volatile uint8_t i2c_pos = 0x00;
+volatile uint8_t i2c_done = 0x00;
+
+#define I2C_FREQ 20000UL
void i2c_init()
{
+ /* SCLf = F_CPU / (16 + 2 * TWBR * 4^TWPS)
+ * TWPS is 0 =>
+ * TWBR = (F_CPU/(2 * SCL)) - 8
+ */
+ TWBR = (F_CPU/(2*I2C_FREQ))-8;
TWAR = BMC_ADDR & 0xfe;
TWDR = 0x00;
TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE));
- printf("Status: 0x%02x\n", TW_STATUS);
+#ifdef __AVR_ATmega16__
PORTC = 0x03;
+#else
+#error "Don't know how to set pullups for this chip, please add support"
+#endif
+}
+
+void i2c_send(unsigned char *buf, int len)
+{
+ 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 != TW_START) {
+#ifdef DEBUG
+ printf("I2C: error sending START\n");
+#endif
+ goto out;
+ }
+
+ TWDR = buf[0]; /* SLA_W */
+ TWCR = ((1<<TWINT) | (1<<TWEN));
+
+ while(!(TWCR & (1<<TWINT))) {}
+ if (TW_STATUS != TW_MT_SLA_ACK) {
+#ifdef DEBUG
+ printf("I2C: error sending SLA_W\n");
+#endif
+ goto out2;
+ }
+
+ for(i = 1; i < len; i++) {
+ TWDR = buf[i]; /* Send Data */
+ TWCR = ((1<<TWINT) | (1<<TWEN));
+
+ while(!(TWCR & (1<<TWINT))) {}
+ if (TW_STATUS != TW_MT_DATA_ACK) {
+#ifdef DEBUG
+ printf("I2C: error sending DATA byte %d\n", i);
+#endif
+ goto out2;
+ }
+ }
+
+#ifdef DEBUG
+ printf("I2C Data sent\n");
+#endif
+
+out2:
+ TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
+ while(TWCR & (1<<TWSTO)) {}
+
+out:
+ SREG = old_SREG;
+ TWCR = old_TWCR | (1<<TWINT);
}
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
- pos = 0x00;
- databuf[pos] = TWDR;
- pos++;
+ i2c_pos = 0x00;
+ i2c_databuf[i2c_pos] = TWDR;
+ i2c_pos++;
TWCR_ACK;
break;
#ifdef DEBUG
printf("I2C: Data received: 0x%02x\n", TWDR);
#endif
- databuf[pos] = TWDR;
- pos++;
+ if (i2c_pos >= sizeof(i2c_databuf)) {
+ TWCR_RESET;
+ i2c_pos = 0x00;
+ break;
+ }
+ i2c_databuf[i2c_pos] = TWDR;
+ i2c_pos++;
TWCR_ACK;
break;
#ifdef DEBUG
printf("I2C: STOP received\n");
#endif
- decode_bmc_cmd((unsigned char*)databuf, pos);
- pos = 0x00;
+ i2c_len = i2c_pos;
+ i2c_pos = 0x00;
+ i2c_done = 0x01;
TWCR_RESET;
break;
+ case TW_NO_INFO:
+#ifdef DEBUG
+ printf("I2C: TW_NO_INFO received status 0x%2x\n", TW_STATUS);
+#endif
+ TWCR |= (1<<TWINT);
+ break;
+
default:
+#ifdef DEBUG
printf("I2C: Unimplemented status 0x%02x\n", TW_STATUS);
+#endif
TWCR_RESET;
break;
}