[linux-2.6-block.git] / drivers / i2c / algos / i2c-algo-pca.c

/*
 *  i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
 *    Copyright (C) 2004 Arcom Control Systems
 *    Copyright (C) 2008 Pengutronix
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pca.h>

#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)

static int i2c_debug;

#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)

#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
#define pca_clock(adap) adap->i2c_clock
#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
#define pca_wait(adap) adap->wait_for_completion(adap->data)
#define pca_reset(adap) adap->reset_chip(adap->data)

/*
 * Generate a start condition on the i2c bus.
 *
 * returns after the start condition has occurred
 */
static void pca_start(struct i2c_algo_pca_data *adap)
{
	int sta = pca_get_con(adap);
	DEB2("=== START\n");
	sta |= I2C_PCA_CON_STA;
	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);
	pca_wait(adap);
}

/*
 * Generate a repeated start condition on the i2c bus
 *
 * return after the repeated start condition has occurred
 */
static void pca_repeated_start(struct i2c_algo_pca_data *adap)
{
	int sta = pca_get_con(adap);
	DEB2("=== REPEATED START\n");
	sta |= I2C_PCA_CON_STA;
	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);
	pca_wait(adap);
}

/*
 * Generate a stop condition on the i2c bus
 *
 * returns after the stop condition has been generated
 *
 * STOPs do not generate an interrupt or set the SI flag, since the
 * part returns the idle state (0xf8). Hence we don't need to
 * pca_wait here.
 */
static void pca_stop(struct i2c_algo_pca_data *adap)
{
	int sta = pca_get_con(adap);
	DEB2("=== STOP\n");
	sta |= I2C_PCA_CON_STO;
	sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);
}

/*
 * Send the slave address and R/W bit
 *
 * returns after the address has been sent
 */
static void pca_address(struct i2c_algo_pca_data *adap,
			struct i2c_msg *msg)
{
	int sta = pca_get_con(adap);
	int addr;

	addr = ( (0x7f & msg->addr) << 1 );
	if (msg->flags & I2C_M_RD )
		addr |= 1;
	DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
	     msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);

	pca_outw(adap, I2C_PCA_DAT, addr);

	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);

	pca_wait(adap);
}

/*
 * Transmit a byte.
 *
 * Returns after the byte has been transmitted
 */
static void pca_tx_byte(struct i2c_algo_pca_data *adap,
			__u8 b)
{
	int sta = pca_get_con(adap);
	DEB2("=== WRITE %#04x\n", b);
	pca_outw(adap, I2C_PCA_DAT, b);

	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);

	pca_wait(adap);
}

/*
 * Receive a byte
 *
 * returns immediately.
 */
static void pca_rx_byte(struct i2c_algo_pca_data *adap,
			__u8 *b, int ack)
{
	*b = pca_inw(adap, I2C_PCA_DAT);
	DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
}

/*
 * Setup ACK or NACK for next received byte and wait for it to arrive.
 *
 * Returns after next byte has arrived.
 */
static void pca_rx_ack(struct i2c_algo_pca_data *adap,
		       int ack)
{
	int sta = pca_get_con(adap);

	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);

	if ( ack )
		sta |= I2C_PCA_CON_AA;

	pca_set_con(adap, sta);
	pca_wait(adap);
}

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 timeout = i2c_adap->timeout;

	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
		msleep(10);
	}
	if (state != 0xf8) {
		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 */
			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);
			goto out;

		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);
			goto out;

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

		case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
			DEB2("Arbitration lost\n");
			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
					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;
		}

	}

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

static u32 pca_func(struct i2c_adapter *adap)
{
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm pca_algo = {
	.master_xfer	= pca_xfer,
	.functionality	= pca_func,
};

static int pca_init(struct i2c_adapter *adap)
{
	static int freqs[] = {330,288,217,146,88,59,44,36};
	int clock;
	struct i2c_algo_pca_data *pca_data = adap->algo_data;

	if (pca_data->i2c_clock > 7) {
		printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
			adap->name);
		pca_data->i2c_clock = I2C_PCA_CON_59kHz;
	}

	adap->algo = &pca_algo;

	pca_reset(pca_data);

	clock = pca_clock(pca_data);
	DEB1(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, freqs[clock]);

	pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
	udelay(500); /* 500 us for oscilator to stabilise */

	return 0;
}

/*
 * registering functions to load algorithms at runtime
 */
int i2c_pca_add_bus(struct i2c_adapter *adap)
{
	int rval;

	rval = pca_init(adap);
	if (rval)
		return rval;

	return i2c_add_adapter(adap);
}
EXPORT_SYMBOL(i2c_pca_add_bus);

int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
{
	int rval;

	rval = pca_init(adap);
	if (rval)
		return rval;

	return i2c_add_numbered_adapter(adap);
}
EXPORT_SYMBOL(i2c_pca_add_numbered_bus);

MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
	"Wolfram Sang <w.sang@pengutronix.de>");
MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
MODULE_LICENSE("GPL");

module_param(i2c_debug, int, 0);
Commit	Line	Data
1da177e4	1	/*
3d438291	2	* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
1da177e4	3	* Copyright (C) 2004 Arcom Control Systems
c01b0831	4	* Copyright (C) 2008 Pengutronix
1da177e4 LT	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23	#include <linux/moduleparam.h>
	24	#include <linux/delay.h>
1da177e4 LT	25	#include <linux/init.h>
	26	#include <linux/errno.h>
	27	#include <linux/i2c.h>
	28	#include <linux/i2c-algo-pca.h>
1da177e4 LT	29
	30	#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
	31	#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
	32	#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)
	33
60507095	34	static int i2c_debug;
1da177e4	35
c01b0831 WS	36	#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
c01b0831 WS	37	#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
1da177e4 LT	38
1da177e4 LT	39	#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
c01b0831	40	#define pca_clock(adap) adap->i2c_clock
1da177e4 LT	41	#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
1da177e4 LT	42	#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
c01b0831 WS	43	#define pca_wait(adap) adap->wait_for_completion(adap->data)
c01b0831 WS	44	#define pca_reset(adap) adap->reset_chip(adap->data)
1da177e4 LT	45
	46	/*
	47	* Generate a start condition on the i2c bus.
	48	*
44bbe87e	49	* returns after the start condition has occurred
1da177e4 LT	50	*/
	51	static void pca_start(struct i2c_algo_pca_data *adap)
	52	{
	53	int sta = pca_get_con(adap);
	54	DEB2("=== START\n");
	55	sta \|= I2C_PCA_CON_STA;
	56	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_SI);
	57	pca_set_con(adap, sta);
	58	pca_wait(adap);
	59	}
	60
	61	/*
46b615f4	62	* Generate a repeated start condition on the i2c bus
1da177e4	63	*
44bbe87e	64	* return after the repeated start condition has occurred
1da177e4 LT	65	*/
	66	static void pca_repeated_start(struct i2c_algo_pca_data *adap)
	67	{
	68	int sta = pca_get_con(adap);
	69	DEB2("=== REPEATED START\n");
	70	sta \|= I2C_PCA_CON_STA;
	71	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_SI);
	72	pca_set_con(adap, sta);
	73	pca_wait(adap);
	74	}
	75
	76	/*
	77	* Generate a stop condition on the i2c bus
	78	*
	79	* returns after the stop condition has been generated
	80	*
	81	* STOPs do not generate an interrupt or set the SI flag, since the
46b615f4	82	* part returns the idle state (0xf8). Hence we don't need to
1da177e4 LT	83	* pca_wait here.
	84	*/
	85	static void pca_stop(struct i2c_algo_pca_data *adap)
	86	{
	87	int sta = pca_get_con(adap);
	88	DEB2("=== STOP\n");
	89	sta \|= I2C_PCA_CON_STO;
	90	sta &= ~(I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	91	pca_set_con(adap, sta);
	92	}
	93
	94	/*
	95	* Send the slave address and R/W bit
	96	*
	97	* returns after the address has been sent
	98	*/
3d438291	99	static void pca_address(struct i2c_algo_pca_data *adap,
1da177e4 LT	100	struct i2c_msg *msg)
	101	{
	102	int sta = pca_get_con(adap);
	103	int addr;
	104
	105	addr = ( (0x7f & msg->addr) << 1 );
	106	if (msg->flags & I2C_M_RD )
	107	addr \|= 1;
3d438291	108	DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
1da177e4	109	msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
3d438291	110
1da177e4 LT	111	pca_outw(adap, I2C_PCA_DAT, addr);
	112
	113	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	114	pca_set_con(adap, sta);
	115
	116	pca_wait(adap);
	117	}
	118
	119	/*
	120	* Transmit a byte.
	121	*
	122	* Returns after the byte has been transmitted
	123	*/
3d438291	124	static void pca_tx_byte(struct i2c_algo_pca_data *adap,
1da177e4 LT	125	__u8 b)
	126	{
	127	int sta = pca_get_con(adap);
	128	DEB2("=== WRITE %#04x\n", b);
	129	pca_outw(adap, I2C_PCA_DAT, b);
	130
	131	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	132	pca_set_con(adap, sta);
	133
	134	pca_wait(adap);
	135	}
	136
	137	/*
	138	* Receive a byte
	139	*
	140	* returns immediately.
	141	*/
3d438291	142	static void pca_rx_byte(struct i2c_algo_pca_data *adap,
1da177e4 LT	143	__u8 *b, int ack)
	144	{
	145	*b = pca_inw(adap, I2C_PCA_DAT);
	146	DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
	147	}
	148
3d438291	149	/*
1da177e4 LT	150	* Setup ACK or NACK for next received byte and wait for it to arrive.
	151	*
	152	* Returns after next byte has arrived.
	153	*/
3d438291	154	static void pca_rx_ack(struct i2c_algo_pca_data *adap,
1da177e4 LT	155	int ack)
	156	{
	157	int sta = pca_get_con(adap);
	158
	159	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI\|I2C_PCA_CON_AA);
	160
	161	if ( ack )
	162	sta \|= I2C_PCA_CON_AA;
	163
	164	pca_set_con(adap, sta);
	165	pca_wait(adap);
	166	}
	167
1da177e4 LT	168	static int pca_xfer(struct i2c_adapter *i2c_adap,
	169	struct i2c_msg *msgs,
	170	int num)
	171	{
	172	struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
	173	struct i2c_msg *msg = NULL;
	174	int curmsg;
	175	int numbytes = 0;
	176	int state;
	177	int ret;
c01b0831	178	int timeout = i2c_adap->timeout;
1da177e4	179
48edcb65 IC	180	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
	181	msleep(10);
	182	}
	183	if (state != 0xf8) {
	184	dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
c80ebe79	185	return -EAGAIN;
1da177e4 LT	186	}
	187
	188	DEB1("{{{ XFER %d messages\n", num);
	189
	190	if (i2c_debug>=2) {
	191	for (curmsg = 0; curmsg < num; curmsg++) {
	192	int addr, i;
	193	msg = &msgs[curmsg];
3d438291	194
1da177e4	195	addr = (0x7f & msg->addr) ;
3d438291	196
1da177e4	197	if (msg->flags & I2C_M_RD )
3d438291	198	printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
1da177e4 LT	199	curmsg, msg->len, addr, (addr<<1) \| 1);
1da177e4 LT	200	else {
3d438291	201	printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
1da177e4 LT	202	curmsg, msg->len, addr, addr<<1,
	203	msg->len == 0 ? "" : ", ");
	204	for(i=0; i < msg->len; i++)
	205	printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
	206	printk("]\n");
	207	}
	208	}
	209	}
	210
	211	curmsg = 0;
	212	ret = -EREMOTEIO;
	213	while (curmsg < num) {
	214	state = pca_status(adap);
	215
	216	DEB3("STATE is 0x%02x\n", state);
	217	msg = &msgs[curmsg];
	218
	219	switch (state) {
	220	case 0xf8: /* On reset or stop the bus is idle */
	221	pca_start(adap);
	222	break;
	223
	224	case 0x08: /* A START condition has been transmitted */
	225	case 0x10: /* A repeated start condition has been transmitted */
	226	pca_address(adap, msg);
	227	break;
3d438291	228
1da177e4 LT	229	case 0x18: /* SLA+W has been transmitted; ACK has been received */
	230	case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
	231	if (numbytes < msg->len) {
	232	pca_tx_byte(adap, msg->buf[numbytes]);
	233	numbytes++;
	234	break;
	235	}
	236	curmsg++; numbytes = 0;
	237	if (curmsg == num)
	238	pca_stop(adap);
	239	else
	240	pca_repeated_start(adap);
	241	break;
	242
	243	case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
	244	DEB2("NOT ACK received after SLA+W\n");
	245	pca_stop(adap);
	246	goto out;
	247
	248	case 0x40: /* SLA+R has been transmitted; ACK has been received */
	249	pca_rx_ack(adap, msg->len > 1);
	250	break;
	251
	252	case 0x50: /* Data bytes has been received; ACK has been returned */
	253	if (numbytes < msg->len) {
	254	pca_rx_byte(adap, &msg->buf[numbytes], 1);
	255	numbytes++;
	256	pca_rx_ack(adap, numbytes < msg->len - 1);
	257	break;
	258	}
	259	curmsg++; numbytes = 0;
	260	if (curmsg == num)
	261	pca_stop(adap);
	262	else
	263	pca_repeated_start(adap);
	264	break;
	265
	266	case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
	267	DEB2("NOT ACK received after SLA+R\n");
	268	pca_stop(adap);
	269	goto out;
	270
	271	case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
	272	DEB2("NOT ACK received after data byte\n");
	273	goto out;
	274
	275	case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
	276	DEB2("Arbitration lost\n");
	277	goto out;
3d438291	278
1da177e4 LT	279	case 0x58: /* Data byte has been received; NOT ACK has been returned */
	280	if ( numbytes == msg->len - 1 ) {
	281	pca_rx_byte(adap, &msg->buf[numbytes], 0);
	282	curmsg++; numbytes = 0;
	283	if (curmsg == num)
	284	pca_stop(adap);
	285	else
	286	pca_repeated_start(adap);
	287	} else {
	288	DEB2("NOT ACK sent after data byte received. "
	289	"Not final byte. numbytes %d. len %d\n",
	290	numbytes, msg->len);
	291	pca_stop(adap);
	292	goto out;
	293	}
	294	break;
	295	case 0x70: /* Bus error - SDA stuck low */
	296	DEB2("BUS ERROR - SDA Stuck low\n");
	297	pca_reset(adap);
	298	goto out;
	299	case 0x90: /* Bus error - SCL stuck low */
	300	DEB2("BUS ERROR - SCL Stuck low\n");
	301	pca_reset(adap);
	302	goto out;
	303	case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
	304	DEB2("BUS ERROR - Illegal START or STOP\n");
	305	pca_reset(adap);
	306	goto out;
	307	default:
c01b0831	308	dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
1da177e4 LT	309	break;
1da177e4 LT	310	}
3d438291	311
1da177e4 LT	312	}
	313
	314	ret = curmsg;
	315	out:
	316	DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
3d438291	317	"status is %#04x. control is %#04x\n",
1da177e4 LT	318	curmsg, num, pca_status(adap),
	319	pca_get_con(adap));
	320	return ret;
	321	}
	322
	323	static u32 pca_func(struct i2c_adapter *adap)
	324	{
	325	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
	326	}
	327
c01b0831 WS	328	static const struct i2c_algorithm pca_algo = {
	329	.master_xfer = pca_xfer,
	330	.functionality = pca_func,
	331	};
	332
	333	static int pca_init(struct i2c_adapter *adap)
1da177e4 LT	334	{
1da177e4 LT	335	static int freqs[] = {330,288,217,146,88,59,44,36};
c01b0831 WS	336	int clock;
	337	struct i2c_algo_pca_data *pca_data = adap->algo_data;
	338
	339	if (pca_data->i2c_clock > 7) {
	340	printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
	341	adap->name);
	342	pca_data->i2c_clock = I2C_PCA_CON_59kHz;
	343	}
	344
	345	adap->algo = &pca_algo;
1da177e4	346
c01b0831	347	pca_reset(pca_data);
1da177e4	348
c01b0831 WS	349	clock = pca_clock(pca_data);
c01b0831 WS	350	DEB1(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, freqs[clock]);
1da177e4	351
c01b0831	352	pca_set_con(pca_data, I2C_PCA_CON_ENSIO \| clock);
3d438291	353	udelay(500); /* 500 us for oscilator to stabilise */
1da177e4 LT	354
	355	return 0;
	356	}
	357
3d438291 WS	358	/*
3d438291 WS	359	* registering functions to load algorithms at runtime
1da177e4 LT	360	*/
	361	int i2c_pca_add_bus(struct i2c_adapter *adap)
	362	{
1da177e4 LT	363	int rval;
1da177e4 LT	364
c01b0831 WS	365	rval = pca_init(adap);
	366	if (rval)
	367	return rval;
1da177e4	368
c01b0831 WS	369	return i2c_add_adapter(adap);
	370	}
	371	EXPORT_SYMBOL(i2c_pca_add_bus);
1da177e4	372
c01b0831 WS	373	int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
	374	{
	375	int rval;
1da177e4	376
c01b0831 WS	377	rval = pca_init(adap);
	378	if (rval)
	379	return rval;
1da177e4	380
c01b0831	381	return i2c_add_numbered_adapter(adap);
1da177e4	382	}
c01b0831	383	EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
1da177e4	384
c01b0831 WS	385	MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
c01b0831 WS	386	"Wolfram Sang <w.sang@pengutronix.de>");
1da177e4 LT	387	MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
	388	MODULE_LICENSE("GPL");
	389
	390	module_param(i2c_debug, int, 0);