static int pca_xfer(struct i2c_adapter *i2c_adap,
		    struct i2c_msg *msgs,
		    int num)
{
	struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
	struct i2c_msg *msg = NULL;
	int curmsg;
	int numbytes = 0;
	int state;
	int ret;
	int completed = 1;
	unsigned long timeout = jiffies + i2c_adap->timeout;

	while ((state = pca_status(adap)) != 0xf8) {
		if (time_before(jiffies, timeout)) {
			msleep(10);
		} else {
			dev_dbg(&i2c_adap->dev, "bus is not idle. status is "
				"%#04x\n", state);
			return -EAGAIN;
		}
	}

	DEB1("{{{ XFER %d messages\n", num);

	if (i2c_debug >= 2) {
		for (curmsg = 0; curmsg < num; curmsg++) {
			int addr, i;
			msg = &msgs[curmsg];

			addr = (0x7f & msg->addr) ;

			if (msg->flags & I2C_M_RD)
				printk(KERN_INFO "    [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
				       curmsg, msg->len, addr, (addr << 1) | 1);
			else {
				printk(KERN_INFO "    [%02d] WR %d bytes to %#02x [%#02x%s",
				       curmsg, msg->len, addr, addr << 1,
				       msg->len == 0 ? "" : ", ");
				for (i = 0; i < msg->len; i++)
					printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
				printk("]\n");
			}
		}
	}

	curmsg = 0;
	ret = -EREMOTEIO;
	while (curmsg < num) {
		state = pca_status(adap);

		DEB3("STATE is 0x%02x\n", state);
		msg = &msgs[curmsg];

		switch (state) {
		case 0xf8: /* On reset or stop the bus is idle */
			completed = pca_start(adap);
			break;

		case 0x08: /* A START condition has been transmitted */
		case 0x10: /* A repeated start condition has been transmitted */
			completed = pca_address(adap, msg);
			break;

		case 0x18: /* SLA+W has been transmitted; ACK has been received */
		case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
			if (numbytes < msg->len) {
				completed = pca_tx_byte(adap,
							msg->buf[numbytes]);
				numbytes++;
				break;
			}
			curmsg++; numbytes = 0;
			if (curmsg == num)
				pca_stop(adap);
			else
				completed = pca_repeated_start(adap);
			break;

		case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after SLA+W\n");
			pca_stop(adap);
			goto out;

		case 0x40: /* SLA+R has been transmitted; ACK has been received */
			completed = pca_rx_ack(adap, msg->len > 1);
			break;

		case 0x50: /* Data bytes has been received; ACK has been returned */
			if (numbytes < msg->len) {
				pca_rx_byte(adap, &msg->buf[numbytes], 1);
				numbytes++;
				completed = pca_rx_ack(adap,
						       numbytes < msg->len - 1);
				break;
			}
			curmsg++; numbytes = 0;
			if (curmsg == num)
				pca_stop(adap);
			else
				completed = pca_repeated_start(adap);
			break;

		case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after SLA+R\n");
			pca_stop(adap);
			goto out;

		case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after data byte\n");
			pca_stop(adap);
			goto out;

		case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
			DEB2("Arbitration lost\n");
			/*
			 * The PCA9564 data sheet (2006-09-01) says "A
			 * START condition will be transmitted when the
			 * bus becomes free (STOP or SCL and SDA high)"
			 * when the STA bit is set (p. 11).
			 *
			 * In case this won't work, try pca_reset()
			 * instead.
			 */
			pca_start(adap);
			goto out;

		case 0x58: /* Data byte has been received; NOT ACK has been returned */
			if (numbytes == msg->len - 1) {
				pca_rx_byte(adap, &msg->buf[numbytes], 0);
				curmsg++; numbytes = 0;
				if (curmsg == num)
					pca_stop(adap);
				else
					completed = pca_repeated_start(adap);
			} else {
				DEB2("NOT ACK sent after data byte received. "
				     "Not final byte. numbytes %d. len %d\n",
				     numbytes, msg->len);
				pca_stop(adap);
				goto out;
			}
			break;
		case 0x70: /* Bus error - SDA stuck low */
			DEB2("BUS ERROR - SDA Stuck low\n");
			pca_reset(adap);
			goto out;
		case 0x90: /* Bus error - SCL stuck low */
			DEB2("BUS ERROR - SCL Stuck low\n");
			pca_reset(adap);
			goto out;
		case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
			DEB2("BUS ERROR - Illegal START or STOP\n");
			pca_reset(adap);
			goto out;
		default:
			dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
			break;
		}

		if (!completed)
			goto out;
	}

	ret = curmsg;
 out:
	DEB1("}}} transfered %d/%d messages. "
	     "status is %#04x. control is %#04x\n",
	     curmsg, num, pca_status(adap),
	     pca_get_con(adap));
	return ret;
}
Esempio n. 2
0
static int pca_xfer(struct i2c_adapter *i2c_adap,
                    struct i2c_msg msgs[],
                    int num)
{
        struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
        struct i2c_msg *msg = NULL;
        int curmsg;
	int numbytes = 0;
	int state;

	state = pca_status(adap);
	if ( state != 0xF8 ) {
		printk(KERN_ERR DRIVER ": bus is not idle. status is %#04x\n", state );
		/* FIXME: what to do. Force stop ? */
		return -EREMOTEIO;
	}

	DEB1("{{{ XFER %d messages\n", num);

	if (i2c_debug>=2) {
		for (curmsg = 0; curmsg < num; curmsg++) {
			int addr, i;
			msg = &msgs[curmsg];
			
			addr = (0x7f & msg->addr) ;
		
			if (msg->flags & I2C_M_RD )
				printk(KERN_INFO "    [%02d] RD %d bytes from %#02x [%#02x, ...]\n", 
				       curmsg, msg->len, addr, (addr<<1) | 1);
			else {
				printk(KERN_INFO "    [%02d] WR %d bytes to %#02x [%#02x%s", 
				       curmsg, msg->len, addr, addr<<1,
				       msg->len == 0 ? "" : ", ");
				for(i=0; i < msg->len; i++)
					printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
				printk("]\n");
			}
		}
	}

	curmsg = 0;
	while (curmsg < num) {
		state = pca_status(adap);

		DEB3("STATE is 0x%02x\n", state);
		msg = &msgs[curmsg];

		switch (state) {
		case 0xf8: /* On reset or stop the bus is idle */
			pca_start(adap);
			break;

		case 0x08: /* A START condition has been transmitted */
		case 0x10: /* A repeated start condition has been transmitted */
			pca_address(adap, msg);
			break;
			
		case 0x18: /* SLA+W has been transmitted; ACK has been received */
		case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
			if (numbytes < msg->len) {
				pca_tx_byte(adap, msg->buf[numbytes]);
				numbytes++;
				break;
			}
			curmsg++; numbytes = 0;
			if (curmsg == num)
				pca_stop(adap);
			else
				pca_repeated_start(adap);
			break;

		case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after SLA+W\n");
			pca_stop(adap);
			return -EREMOTEIO;

		case 0x40: /* SLA+R has been transmitted; ACK has been received */
			pca_rx_ack(adap, msg->len > 1);
			break;

		case 0x50: /* Data bytes has been received; ACK has been returned */
			if (numbytes < msg->len) {
				pca_rx_byte(adap, &msg->buf[numbytes], 1);
				numbytes++;
				pca_rx_ack(adap, numbytes < msg->len - 1);
				break;
			} 
			curmsg++; numbytes = 0;
			if (curmsg == num)
				pca_stop(adap);
			else
				pca_repeated_start(adap);
			break;

		case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after SLA+R\n");
			pca_stop(adap);
			return -EREMOTEIO;

		case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
			DEB2("NOT ACK received after data byte\n");
			return -EREMOTEIO;

		case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
			DEB2("Arbitration lost\n");
			return -EREMOTEIO;
			
		case 0x58: /* Data byte has been received; NOT ACK has been returned */
			if ( numbytes == msg->len - 1 ) {
				pca_rx_byte(adap, &msg->buf[numbytes], 0);
				curmsg++; numbytes = 0;
				if (curmsg == num)
					pca_stop(adap);
				else
					pca_repeated_start(adap);
			} else {
				DEB2("NOT ACK sent after data byte received. "
				     "Not final byte. numbytes %d. len %d\n",
				     numbytes, msg->len);
				pca_stop(adap);
				return -EREMOTEIO;
			}
			break;
		case 0x70: /* Bus error - SDA stuck low */
			DEB2("BUS ERROR - SDA Stuck low\n");
			pca_reset(adap);
			return -EREMOTEIO;
		case 0x90: /* Bus error - SCL stuck low */
			DEB2("BUS ERROR - SCL Stuck low\n");
			pca_reset(adap);
			return -EREMOTEIO;
		case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
			DEB2("BUS ERROR - Illegal START or STOP\n");
			pca_reset(adap);
			return -EREMOTEIO;
		default:
			printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
			break;
		}
		
	}

	DEB1(KERN_CRIT "}}} transfered %d messages. "
	     "status is %#04x. control is %#04x\n", 
	     num, pca_status(adap),
	     pca_get_con(adap));
	return curmsg;
}