[mirror_ubuntu-artful-kernel.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(KERN_DEBUG fmt, ## args); } while (0)
#define DEB2(fmt, args...) do { if (i2c_debug >= 2)			\
				 printk(KERN_DEBUG fmt, ## args); } while (0)
#define DEB3(fmt, args...) do { if (i2c_debug >= 3)			\
				 printk(KERN_DEBUG 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("}}} 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);
	printk(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	29
bac3e7c2 FS	30	#define DEB1(fmt, args...) do { if (i2c_debug >= 1) \
	31	printk(KERN_DEBUG fmt, ## args); } while (0)
	32	#define DEB2(fmt, args...) do { if (i2c_debug >= 2) \
	33	printk(KERN_DEBUG fmt, ## args); } while (0)
	34	#define DEB3(fmt, args...) do { if (i2c_debug >= 3) \
	35	printk(KERN_DEBUG fmt, ## args); } while (0)
1da177e4	36
60507095	37	static int i2c_debug;
1da177e4	38
c01b0831 WS	39	#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
c01b0831 WS	40	#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
1da177e4 LT	41
1da177e4 LT	42	#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
c01b0831	43	#define pca_clock(adap) adap->i2c_clock
1da177e4 LT	44	#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
1da177e4 LT	45	#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
c01b0831 WS	46	#define pca_wait(adap) adap->wait_for_completion(adap->data)
c01b0831 WS	47	#define pca_reset(adap) adap->reset_chip(adap->data)
1da177e4 LT	48
	49	/*
	50	* Generate a start condition on the i2c bus.
	51	*
44bbe87e	52	* returns after the start condition has occurred
1da177e4 LT	53	*/
	54	static void pca_start(struct i2c_algo_pca_data *adap)
	55	{
	56	int sta = pca_get_con(adap);
	57	DEB2("=== START\n");
	58	sta \|= I2C_PCA_CON_STA;
	59	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_SI);
	60	pca_set_con(adap, sta);
	61	pca_wait(adap);
	62	}
	63
	64	/*
46b615f4	65	* Generate a repeated start condition on the i2c bus
1da177e4	66	*
44bbe87e	67	* return after the repeated start condition has occurred
1da177e4 LT	68	*/
	69	static void pca_repeated_start(struct i2c_algo_pca_data *adap)
	70	{
	71	int sta = pca_get_con(adap);
	72	DEB2("=== REPEATED START\n");
	73	sta \|= I2C_PCA_CON_STA;
	74	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_SI);
	75	pca_set_con(adap, sta);
	76	pca_wait(adap);
	77	}
	78
	79	/*
	80	* Generate a stop condition on the i2c bus
	81	*
	82	* returns after the stop condition has been generated
	83	*
	84	* STOPs do not generate an interrupt or set the SI flag, since the
46b615f4	85	* part returns the idle state (0xf8). Hence we don't need to
1da177e4 LT	86	* pca_wait here.
	87	*/
	88	static void pca_stop(struct i2c_algo_pca_data *adap)
	89	{
	90	int sta = pca_get_con(adap);
	91	DEB2("=== STOP\n");
	92	sta \|= I2C_PCA_CON_STO;
	93	sta &= ~(I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	94	pca_set_con(adap, sta);
	95	}
	96
	97	/*
	98	* Send the slave address and R/W bit
	99	*
	100	* returns after the address has been sent
	101	*/
3d438291	102	static void pca_address(struct i2c_algo_pca_data *adap,
1da177e4 LT	103	struct i2c_msg *msg)
	104	{
	105	int sta = pca_get_con(adap);
	106	int addr;
	107
	108	addr = ( (0x7f & msg->addr) << 1 );
	109	if (msg->flags & I2C_M_RD )
	110	addr \|= 1;
3d438291	111	DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
1da177e4	112	msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
3d438291	113
1da177e4 LT	114	pca_outw(adap, I2C_PCA_DAT, addr);
	115
	116	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	117	pca_set_con(adap, sta);
	118
	119	pca_wait(adap);
	120	}
	121
	122	/*
	123	* Transmit a byte.
	124	*
	125	* Returns after the byte has been transmitted
	126	*/
3d438291	127	static void pca_tx_byte(struct i2c_algo_pca_data *adap,
1da177e4 LT	128	__u8 b)
	129	{
	130	int sta = pca_get_con(adap);
	131	DEB2("=== WRITE %#04x\n", b);
	132	pca_outw(adap, I2C_PCA_DAT, b);
	133
	134	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI);
	135	pca_set_con(adap, sta);
	136
	137	pca_wait(adap);
	138	}
	139
	140	/*
	141	* Receive a byte
	142	*
	143	* returns immediately.
	144	*/
3d438291	145	static void pca_rx_byte(struct i2c_algo_pca_data *adap,
1da177e4 LT	146	__u8 *b, int ack)
	147	{
	148	*b = pca_inw(adap, I2C_PCA_DAT);
	149	DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
	150	}
	151
3d438291	152	/*
1da177e4 LT	153	* Setup ACK or NACK for next received byte and wait for it to arrive.
	154	*
	155	* Returns after next byte has arrived.
	156	*/
3d438291	157	static void pca_rx_ack(struct i2c_algo_pca_data *adap,
1da177e4 LT	158	int ack)
	159	{
	160	int sta = pca_get_con(adap);
	161
	162	sta &= ~(I2C_PCA_CON_STO\|I2C_PCA_CON_STA\|I2C_PCA_CON_SI\|I2C_PCA_CON_AA);
	163
	164	if ( ack )
	165	sta \|= I2C_PCA_CON_AA;
	166
	167	pca_set_con(adap, sta);
	168	pca_wait(adap);
	169	}
	170
1da177e4 LT	171	static int pca_xfer(struct i2c_adapter *i2c_adap,
	172	struct i2c_msg *msgs,
	173	int num)
	174	{
	175	struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
	176	struct i2c_msg *msg = NULL;
	177	int curmsg;
	178	int numbytes = 0;
	179	int state;
	180	int ret;
c01b0831	181	int timeout = i2c_adap->timeout;
1da177e4	182
48edcb65 IC	183	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
	184	msleep(10);
	185	}
	186	if (state != 0xf8) {
	187	dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
c80ebe79	188	return -EAGAIN;
1da177e4 LT	189	}
	190
	191	DEB1("{{{ XFER %d messages\n", num);
	192
	193	if (i2c_debug>=2) {
	194	for (curmsg = 0; curmsg < num; curmsg++) {
	195	int addr, i;
	196	msg = &msgs[curmsg];
3d438291	197
1da177e4	198	addr = (0x7f & msg->addr) ;
3d438291	199
1da177e4	200	if (msg->flags & I2C_M_RD )
3d438291	201	printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
1da177e4 LT	202	curmsg, msg->len, addr, (addr<<1) \| 1);
1da177e4 LT	203	else {
3d438291	204	printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
1da177e4 LT	205	curmsg, msg->len, addr, addr<<1,
	206	msg->len == 0 ? "" : ", ");
	207	for(i=0; i < msg->len; i++)
	208	printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
	209	printk("]\n");
	210	}
	211	}
	212	}
	213
	214	curmsg = 0;
	215	ret = -EREMOTEIO;
	216	while (curmsg < num) {
	217	state = pca_status(adap);
	218
	219	DEB3("STATE is 0x%02x\n", state);
	220	msg = &msgs[curmsg];
	221
	222	switch (state) {
	223	case 0xf8: /* On reset or stop the bus is idle */
	224	pca_start(adap);
	225	break;
	226
	227	case 0x08: /* A START condition has been transmitted */
	228	case 0x10: /* A repeated start condition has been transmitted */
	229	pca_address(adap, msg);
	230	break;
3d438291	231
1da177e4 LT	232	case 0x18: /* SLA+W has been transmitted; ACK has been received */
	233	case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
	234	if (numbytes < msg->len) {
	235	pca_tx_byte(adap, msg->buf[numbytes]);
	236	numbytes++;
	237	break;
	238	}
	239	curmsg++; numbytes = 0;
	240	if (curmsg == num)
	241	pca_stop(adap);
	242	else
	243	pca_repeated_start(adap);
	244	break;
	245
	246	case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
	247	DEB2("NOT ACK received after SLA+W\n");
	248	pca_stop(adap);
	249	goto out;
	250
	251	case 0x40: /* SLA+R has been transmitted; ACK has been received */
	252	pca_rx_ack(adap, msg->len > 1);
	253	break;
	254
	255	case 0x50: /* Data bytes has been received; ACK has been returned */
	256	if (numbytes < msg->len) {
	257	pca_rx_byte(adap, &msg->buf[numbytes], 1);
	258	numbytes++;
	259	pca_rx_ack(adap, numbytes < msg->len - 1);
	260	break;
	261	}
	262	curmsg++; numbytes = 0;
	263	if (curmsg == num)
	264	pca_stop(adap);
	265	else
	266	pca_repeated_start(adap);
	267	break;
	268
	269	case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
	270	DEB2("NOT ACK received after SLA+R\n");
	271	pca_stop(adap);
	272	goto out;
	273
	274	case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
	275	DEB2("NOT ACK received after data byte\n");
	276	goto out;
	277
	278	case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
	279	DEB2("Arbitration lost\n");
	280	goto out;
3d438291	281
1da177e4 LT	282	case 0x58: /* Data byte has been received; NOT ACK has been returned */
	283	if ( numbytes == msg->len - 1 ) {
	284	pca_rx_byte(adap, &msg->buf[numbytes], 0);
	285	curmsg++; numbytes = 0;
	286	if (curmsg == num)
	287	pca_stop(adap);
	288	else
	289	pca_repeated_start(adap);
	290	} else {
	291	DEB2("NOT ACK sent after data byte received. "
	292	"Not final byte. numbytes %d. len %d\n",
	293	numbytes, msg->len);
	294	pca_stop(adap);
	295	goto out;
	296	}
	297	break;
	298	case 0x70: /* Bus error - SDA stuck low */
	299	DEB2("BUS ERROR - SDA Stuck low\n");
	300	pca_reset(adap);
	301	goto out;
	302	case 0x90: /* Bus error - SCL stuck low */
	303	DEB2("BUS ERROR - SCL Stuck low\n");
	304	pca_reset(adap);
	305	goto out;
	306	case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
	307	DEB2("BUS ERROR - Illegal START or STOP\n");
	308	pca_reset(adap);
	309	goto out;
	310	default:
c01b0831	311	dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
1da177e4 LT	312	break;
1da177e4 LT	313	}
3d438291	314
1da177e4 LT	315	}
	316
	317	ret = curmsg;
	318	out:
bac3e7c2	319	DEB1("}}} transfered %d/%d messages. "
3d438291	320	"status is %#04x. control is %#04x\n",
1da177e4 LT	321	curmsg, num, pca_status(adap),
	322	pca_get_con(adap));
	323	return ret;
	324	}
	325
	326	static u32 pca_func(struct i2c_adapter *adap)
	327	{
	328	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
	329	}
	330
c01b0831 WS	331	static const struct i2c_algorithm pca_algo = {
	332	.master_xfer = pca_xfer,
	333	.functionality = pca_func,
	334	};
	335
	336	static int pca_init(struct i2c_adapter *adap)
1da177e4 LT	337	{
1da177e4 LT	338	static int freqs[] = {330,288,217,146,88,59,44,36};
c01b0831 WS	339	int clock;
	340	struct i2c_algo_pca_data *pca_data = adap->algo_data;
	341
	342	if (pca_data->i2c_clock > 7) {
	343	printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
	344	adap->name);
	345	pca_data->i2c_clock = I2C_PCA_CON_59kHz;
	346	}
	347
	348	adap->algo = &pca_algo;
1da177e4	349
c01b0831	350	pca_reset(pca_data);
1da177e4	351
c01b0831	352	clock = pca_clock(pca_data);
bac3e7c2 FS	353	printk(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name,
bac3e7c2 FS	354	freqs[clock]);
1da177e4	355
c01b0831	356	pca_set_con(pca_data, I2C_PCA_CON_ENSIO \| clock);
3d438291	357	udelay(500); /* 500 us for oscilator to stabilise */
1da177e4 LT	358
	359	return 0;
	360	}
	361
3d438291 WS	362	/*
3d438291 WS	363	* registering functions to load algorithms at runtime
1da177e4 LT	364	*/
	365	int i2c_pca_add_bus(struct i2c_adapter *adap)
	366	{
1da177e4 LT	367	int rval;
1da177e4 LT	368
c01b0831 WS	369	rval = pca_init(adap);
	370	if (rval)
	371	return rval;
1da177e4	372
c01b0831 WS	373	return i2c_add_adapter(adap);
	374	}
	375	EXPORT_SYMBOL(i2c_pca_add_bus);
1da177e4	376
c01b0831 WS	377	int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
	378	{
	379	int rval;
1da177e4	380
c01b0831 WS	381	rval = pca_init(adap);
	382	if (rval)
	383	return rval;
1da177e4	384
c01b0831	385	return i2c_add_numbered_adapter(adap);
1da177e4	386	}
c01b0831	387	EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
1da177e4	388
c01b0831 WS	389	MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
c01b0831 WS	390	"Wolfram Sang <w.sang@pengutronix.de>");
1da177e4 LT	391	MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
	392	MODULE_LICENSE("GPL");
	393
	394	module_param(i2c_debug, int, 0);