[rsbs2] / bmc / i2c.c

#include <util/twi.h>
#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[24];
volatile uint8_t i2c_len = 0x00;
static volatile uint8_t i2c_pos = 0x00;
volatile uint8_t i2c_done = 0x00;

void i2c_init()
{
	TWBR = 0xff;
	TWAR = BMC_ADDR & 0xfe;
	TWDR = 0x00;
	TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
	TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE)); 
#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 & 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 & 0xf8) {
		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
			if (i2c_pos >= sizeof(i2c_databuf)) {
				TWCR_RESET;
				i2c_pos = 0x00;
				break;
			}
			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:
#ifdef DEBUG
			printf("I2C: Unimplemented status 0x%02x\n", (TW_STATUS & 0xf8));
#endif
			TWCR_RESET;
			break;
	}
}
Commit	Line	Data
99e4226b MG	1	#include <util/twi.h>
	2	#include <avr/interrupt.h>
	3	#include <stdio.h>
	4	#include "i2c.h"
da7751cb	5	#include "bmc.h"
d5193055	6	#include "ipmb.h"
99e4226b MG	7
	8	#define TWCR_ACK TWCR = (1<<TWEN)\|(1<<TWIE)\|(1<<TWINT)\|(1<<TWEA)\|(0<<TWSTA)\|(0<<TWSTO)\|(0<<TWWC);
	9	#define TWCR_NACK TWCR = (1<<TWEN)\|(1<<TWIE)\|(1<<TWINT)\|(0<<TWEA)\|(0<<TWSTA)\|(0<<TWSTO)\|(0<<TWWC);
	10	#define TWCR_RESET TWCR = (1<<TWEN)\|(1<<TWIE)\|(1<<TWINT)\|(1<<TWEA)\|(0<<TWSTA)\|(1<<TWSTO)\|(0<<TWWC);
	11
45320371	12	volatile unsigned char i2c_databuf[24];
da7751cb MG	13	volatile uint8_t i2c_len = 0x00;
	14	static volatile uint8_t i2c_pos = 0x00;
	15	volatile uint8_t i2c_done = 0x00;
77ad1a84	16
99e4226b MG	17	void i2c_init()
99e4226b MG	18	{
da7751cb	19	TWBR = 0xff;
7f52e040 MG	20	TWAR = BMC_ADDR & 0xfe;
	21	TWDR = 0x00;
	22	TWCR &= ~((1<<TWSTA) \| (1<<TWSTO));
	23	TWCR \|= ((1<<TWEA) \| (1<<TWEN) \| (1<<TWIE));
e641fce6	24	#ifdef __AVR_ATmega16__
7f52e040	25	PORTC = 0x03;
e641fce6 MG	26	#else
	27	#error "Don't know how to set pullups for this chip, please add support"
	28	#endif
99e4226b MG	29	}
99e4226b MG	30
d5193055 MG	31	void i2c_send(unsigned char *buf, int len)
	32	{
	33	uint8_t old_TWCR = TWCR;
	34	uint8_t old_SREG = SREG;
	35	int i;
	36
	37	cli();
	38
	39	TWCR = ((1<<TWINT) \| (1<<TWSTA) \| (1<<TWEN)); /* Send start */
	40
	41	while(!(TWCR & (1<<TWINT))) {}
	42	if ((TW_STATUS & 0xf8) != TW_START)
	43	goto out;
	44
	45	TWDR = buf[0]; /* SLA_W */
	46	TWCR = ((1<<TWINT) \| (1<<TWEN));
	47
	48	while(!(TWCR & (1<<TWINT))) {}
	49	if ((TW_STATUS & 0xf8) != TW_MT_SLA_ACK)
	50	goto out;
	51
	52	for(i = 1; i < len; i++) {
	53	TWDR = buf[i]; /* Send Data */
	54	TWCR = ((1<<TWINT) \| (1<<TWEN));
	55
	56	while(!(TWCR & (1<<TWINT))) {}
	57	if ((TW_STATUS & 0xf8) != TW_MT_DATA_ACK)
	58	goto out;
	59	}
	60
	61	TWCR = ((1<<TWINT) \| (1<<TWEN) \| (1<<TWSTO));
27f7ea19	62	while(TWCR & (1<<TWSTO)) {}
d5193055	63
27f7ea19	64	#ifdef DEBUG
da7751cb MG	65	printf("I2C Data sent\n");
da7751cb MG	66	#endif
d5193055 MG	67
	68	out:
	69	TWDR = 0x00;
	70	TWCR = old_TWCR;
	71	SREG = old_SREG;
	72	}
	73
7f52e040	74	ISR (TWI_vect, ISR_BLOCK)
99e4226b	75	{
da7751cb MG	76	if (i2c_done)
	77	TWCR_RESET;
	78
75a01977	79	switch (TW_STATUS & 0xf8) {
77ad1a84 MG	80	case TW_SR_SLA_ACK:
	81	#ifdef DEBUG
	82	printf("I2C: Slave 0x%02x adressed\n", TWDR);
	83	#endif
da7751cb MG	84	i2c_pos = 0x00;
	85	i2c_databuf[i2c_pos] = TWDR;
	86	i2c_pos++;
77ad1a84 MG	87	TWCR_ACK;
	88	break;
	89
	90	case TW_SR_DATA_ACK:
	91	#ifdef DEBUG
	92	printf("I2C: Data received: 0x%02x\n", TWDR);
	93	#endif
a44532dc MG	94	if (i2c_pos >= sizeof(i2c_databuf)) {
	95	TWCR_RESET;
	96	i2c_pos = 0x00;
	97	break;
	98	}
da7751cb MG	99	i2c_databuf[i2c_pos] = TWDR;
da7751cb MG	100	i2c_pos++;
77ad1a84 MG	101	TWCR_ACK;
	102	break;
	103
	104	case TW_SR_STOP:
	105	#ifdef DEBUG
	106	printf("I2C: STOP received\n");
	107	#endif
da7751cb MG	108	i2c_len = i2c_pos;
	109	i2c_pos = 0x00;
	110	i2c_done = 0x01;
77ad1a84 MG	111	TWCR_RESET;
	112	break;
	113
77ad1a84	114	default:
f9d5c6e0	115	#ifdef DEBUG
75a01977	116	printf("I2C: Unimplemented status 0x%02x\n", (TW_STATUS & 0xf8));
f9d5c6e0	117	#endif
77ad1a84 MG	118	TWCR_RESET;
77ad1a84 MG	119	break;
99e4226b MG	120	}
99e4226b MG	121	}