[net-next-2.6.git] / drivers / i2c / algos / i2c-algo-pca.c

/*
 *  i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters                
 *    Copyright (C) 2004 Arcom Control Systems
 *
 *  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/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pca.h>
#include "i2c-algo-pca.h"

#define DRIVER "i2c-algo-pca"

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

#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
#define pca_clock(adap) adap->get_clock(adap)
#define pca_own(adap) adap->get_own(adap)
#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_interrupt(adap)

/*
 * 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);
}

/* 
 * Reset the i2c bus / SIO 
 */
static void pca_reset(struct i2c_algo_pca_data *adap)
{
	/* apparently only an external reset will do it. not a lot can be done */
	printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
}

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 = 100;

	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 -EIO;
	}

	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:
			printk(KERN_ERR DRIVER ": 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 int pca_init(struct i2c_algo_pca_data *adap)
{
	static int freqs[] = {330,288,217,146,88,59,44,36};
	int own, clock;

	own = pca_own(adap);
	clock = pca_clock(adap);
	DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
	DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);

	pca_outw(adap, I2C_PCA_ADR, own << 1);

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

	return 0;
}

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

/* 
 * registering functions to load algorithms at runtime 
 */
int i2c_pca_add_bus(struct i2c_adapter *adap)
{
	struct i2c_algo_pca_data *pca_adap = adap->algo_data;
	int rval;

	/* register new adapter to i2c module... */
	adap->algo = &pca_algo;

	adap->timeout = 100;		/* default values, should	*/
	adap->retries = 3;		/* be replaced by defines	*/

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

	rval = i2c_add_adapter(adap);

	return rval;
}
EXPORT_SYMBOL(i2c_pca_add_bus);

MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
MODULE_LICENSE("GPL");

module_param(i2c_debug, int, 0);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
	3	* Copyright (C) 2004 Arcom Control Systems
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	18	*/
	19
	20	#include <linux/kernel.h>
	21	#include <linux/module.h>
	22	#include <linux/moduleparam.h>
	23	#include <linux/delay.h>
	24	#include <linux/slab.h>
	25	#include <linux/init.h>
	26	#include <linux/errno.h>
	27	#include <linux/i2c.h>
	28	#include <linux/i2c-algo-pca.h>
	29	#include "i2c-algo-pca.h"
	30
	31	#define DRIVER "i2c-algo-pca"
	32
	33	#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
	34	#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
	35	#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)
	36
60507095	37	static int i2c_debug;
1da177e4 LT	38
	39	#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
	40	#define pca_inw(adap, reg) adap->read_byte(adap, reg)
	41
	42	#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
	43	#define pca_clock(adap) adap->get_clock(adap)
	44	#define pca_own(adap) adap->get_own(adap)
	45	#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
	46	#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
	47	#define pca_wait(adap) adap->wait_for_interrupt(adap)
	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	*/
	102	static void pca_address(struct i2c_algo_pca_data *adap,
	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;
	111	DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
	112	msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
	113
	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	*/
	127	static void pca_tx_byte(struct i2c_algo_pca_data *adap,
	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	*/
	145	static void pca_rx_byte(struct i2c_algo_pca_data *adap,
	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
152	/*
153	* Setup ACK or NACK for next received byte and wait for it to arrive.
154	*
155	* Returns after next byte has arrived.
156	*/
157	static void pca_rx_ack(struct i2c_algo_pca_data *adap,
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
171	/*
172	* Reset the i2c bus / SIO
173	*/
174	static void pca_reset(struct i2c_algo_pca_data *adap)
175	{
176	/* apparently only an external reset will do it. not a lot can be done */
177	printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
178	}
179
180	static int pca_xfer(struct i2c_adapter *i2c_adap,
181	struct i2c_msg *msgs,
182	int num)
183	{
184	struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
185	struct i2c_msg *msg = NULL;
186	int curmsg;
187	int numbytes = 0;
188	int state;
189	int ret;
48edcb65	190	int timeout = 100;
1da177e4	191
48edcb65 IC	192	while ((state = pca_status(adap)) != 0xf8 && timeout--) {
	193	msleep(10);
	194	}
	195	if (state != 0xf8) {
	196	dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
	197	return -EIO;
1da177e4 LT	198	}
	199
	200	DEB1("{{{ XFER %d messages\n", num);
	201
	202	if (i2c_debug>=2) {
	203	for (curmsg = 0; curmsg < num; curmsg++) {
	204	int addr, i;
	205	msg = &msgs[curmsg];
	206
	207	addr = (0x7f & msg->addr) ;
	208
	209	if (msg->flags & I2C_M_RD )
	210	printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
	211	curmsg, msg->len, addr, (addr<<1) \| 1);
	212	else {
	213	printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
	214	curmsg, msg->len, addr, addr<<1,
	215	msg->len == 0 ? "" : ", ");
	216	for(i=0; i < msg->len; i++)
	217	printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
	218	printk("]\n");
	219	}
	220	}
	221	}
	222
	223	curmsg = 0;
	224	ret = -EREMOTEIO;
	225	while (curmsg < num) {
	226	state = pca_status(adap);
	227
	228	DEB3("STATE is 0x%02x\n", state);
	229	msg = &msgs[curmsg];
	230
	231	switch (state) {
	232	case 0xf8: /* On reset or stop the bus is idle */
	233	pca_start(adap);
	234	break;
	235
	236	case 0x08: /* A START condition has been transmitted */
	237	case 0x10: /* A repeated start condition has been transmitted */
	238	pca_address(adap, msg);
	239	break;
	240
	241	case 0x18: /* SLA+W has been transmitted; ACK has been received */
	242	case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
	243	if (numbytes < msg->len) {
	244	pca_tx_byte(adap, msg->buf[numbytes]);
	245	numbytes++;
	246	break;
	247	}
	248	curmsg++; numbytes = 0;
	249	if (curmsg == num)
	250	pca_stop(adap);
	251	else
	252	pca_repeated_start(adap);
	253	break;
	254
	255	case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
	256	DEB2("NOT ACK received after SLA+W\n");
	257	pca_stop(adap);
	258	goto out;
	259
	260	case 0x40: /* SLA+R has been transmitted; ACK has been received */
	261	pca_rx_ack(adap, msg->len > 1);
262	break;
263
264	case 0x50: /* Data bytes has been received; ACK has been returned */
265	if (numbytes < msg->len) {
266	pca_rx_byte(adap, &msg->buf[numbytes], 1);
267	numbytes++;
268	pca_rx_ack(adap, numbytes < msg->len - 1);
269	break;
270	}
271	curmsg++; numbytes = 0;
272	if (curmsg == num)
273	pca_stop(adap);
274	else
275	pca_repeated_start(adap);
276	break;
277
278	case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
279	DEB2("NOT ACK received after SLA+R\n");
280	pca_stop(adap);
281	goto out;
282
283	case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
284	DEB2("NOT ACK received after data byte\n");
285	goto out;
286
287	case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
288	DEB2("Arbitration lost\n");
289	goto out;
290
291	case 0x58: /* Data byte has been received; NOT ACK has been returned */
292	if ( numbytes == msg->len - 1 ) {
293	pca_rx_byte(adap, &msg->buf[numbytes], 0);
294	curmsg++; numbytes = 0;
295	if (curmsg == num)
296	pca_stop(adap);
297	else
298	pca_repeated_start(adap);
299	} else {
300	DEB2("NOT ACK sent after data byte received. "
301	"Not final byte. numbytes %d. len %d\n",
302	numbytes, msg->len);
303	pca_stop(adap);
304	goto out;
305	}
306	break;
307	case 0x70: /* Bus error - SDA stuck low */
308	DEB2("BUS ERROR - SDA Stuck low\n");
309	pca_reset(adap);
310	goto out;
311	case 0x90: /* Bus error - SCL stuck low */
312	DEB2("BUS ERROR - SCL Stuck low\n");
313	pca_reset(adap);
314	goto out;
315	case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
316	DEB2("BUS ERROR - Illegal START or STOP\n");
317	pca_reset(adap);
318	goto out;
319	default:
320	printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
321	break;
322	}
323
324	}
325
326	ret = curmsg;
327	out:
328	DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
329	"status is %#04x. control is %#04x\n",
330	curmsg, num, pca_status(adap),
331	pca_get_con(adap));
332	return ret;
333	}
334
335	static u32 pca_func(struct i2c_adapter *adap)
336	{
337	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
338	}
339
340	static int pca_init(struct i2c_algo_pca_data *adap)
341	{
342	static int freqs[] = {330,288,217,146,88,59,44,36};
343	int own, clock;
344
345	own = pca_own(adap);
346	clock = pca_clock(adap);
347	DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
348	DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
349
350	pca_outw(adap, I2C_PCA_ADR, own << 1);
351
352	pca_set_con(adap, I2C_PCA_CON_ENSIO \| clock);
96de0e25	353	udelay(500); /* 500 µs for oscilator to stabilise */
1da177e4 LT	354
	355	return 0;
	356	}
	357
9e11a9fb	358	static const struct i2c_algorithm pca_algo = {
1da177e4 LT	359	.master_xfer = pca_xfer,
	360	.functionality = pca_func,
	361	};
	362
	363	/*
	364	* registering functions to load algorithms at runtime
	365	*/
	366	int i2c_pca_add_bus(struct i2c_adapter *adap)
	367	{
	368	struct i2c_algo_pca_data *pca_adap = adap->algo_data;
	369	int rval;
	370
	371	/* register new adapter to i2c module... */
1da177e4 LT	372	adap->algo = &pca_algo;
	373
	374	adap->timeout = 100; /* default values, should */
	375	adap->retries = 3; /* be replaced by defines */
	376
b39ad0cf MH	377	if ((rval = pca_init(pca_adap)))
b39ad0cf MH	378	return rval;
1da177e4	379
b39ad0cf	380	rval = i2c_add_adapter(adap);
1da177e4 LT	381
	382	return rval;
	383	}
1da177e4	384	EXPORT_SYMBOL(i2c_pca_add_bus);
1da177e4 LT	385
	386	MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
	387	MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
	388	MODULE_LICENSE("GPL");
	389
	390	module_param(i2c_debug, int, 0);