[deliverable/linux.git] / drivers / i2c / algos / i2c-algo-pcf.c

/*
 * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
 *
 *   Copyright (C) 1995-1997 Simon G. Vogl
 *		   1998-2000 Hans Berglund
 *
 *  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.
 *
 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
 * Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
 * <mbailey@littlefeet-inc.com>
 *
 * Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
 * messages, proper stop/repstart signaling during receive, added detect code
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pcf.h>
#include "i2c-algo-pcf.h"


#define DEB2(x) if (i2c_debug >= 2) x
#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
#define DEBPROTO(x) if (i2c_debug >= 9) x;
	/* debug the protocol by showing transferred bits */
#define DEF_TIMEOUT 16

/*
 * module parameters:
 */
static int i2c_debug;

/* setting states on the bus with the right timing: */

#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
#define get_own(adap) adap->getown(adap->data)
#define get_clock(adap) adap->getclock(adap->data)
#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
#define i2c_inb(adap) adap->getpcf(adap->data, 0)

/* other auxiliary functions */

static void i2c_start(struct i2c_algo_pcf_data *adap)
{
	DEBPROTO(printk(KERN_DEBUG "S "));
	set_pcf(adap, 1, I2C_PCF_START);
}

static void i2c_repstart(struct i2c_algo_pcf_data *adap)
{
	DEBPROTO(printk(" Sr "));
	set_pcf(adap, 1, I2C_PCF_REPSTART);
}

static void i2c_stop(struct i2c_algo_pcf_data *adap)
{
	DEBPROTO(printk("P\n"));
	set_pcf(adap, 1, I2C_PCF_STOP);
}

static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
{
	DEB2(printk(KERN_INFO
		"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
		*status));
	/*
	 * Cleanup from LAB -- reset and enable ESO.
	 * This resets the PCF8584; since we've lost the bus, no
	 * further attempts should be made by callers to clean up
	 * (no i2c_stop() etc.)
	 */
	set_pcf(adap, 1, I2C_PCF_PIN);
	set_pcf(adap, 1, I2C_PCF_ESO);
	/*
	 * We pause for a time period sufficient for any running
	 * I2C transaction to complete -- the arbitration logic won't
	 * work properly until the next START is seen.
	 * It is assumed the bus driver or client has set a proper value.
	 *
	 * REVISIT: should probably use msleep instead of mdelay if we
	 * know we can sleep.
	 */
	if (adap->lab_mdelay)
		mdelay(adap->lab_mdelay);

	DEB2(printk(KERN_INFO
		"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
		get_pcf(adap, 1)));
}

static int wait_for_bb(struct i2c_algo_pcf_data *adap)
{

	int timeout = DEF_TIMEOUT;
	int status;

	status = get_pcf(adap, 1);

	while (!(status & I2C_PCF_BB) && --timeout) {
		udelay(100); /* wait for 100 us */
		status = get_pcf(adap, 1);
	}

	if (timeout == 0) {
		printk(KERN_ERR "Timeout waiting for Bus Busy\n");
		return -ETIMEDOUT;
	}

	return 0;
}

static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
{

	int timeout = DEF_TIMEOUT;

	*status = get_pcf(adap, 1);

	while ((*status & I2C_PCF_PIN) && --timeout) {
		adap->waitforpin(adap->data);
		*status = get_pcf(adap, 1);
	}
	if (*status & I2C_PCF_LAB) {
		handle_lab(adap, status);
		return -EINTR;
	}

	if (timeout == 0)
		return -ETIMEDOUT;

	return 0;
}

/*
 * This should perform the 'PCF8584 initialization sequence' as described
 * in the Philips IC12 data book (1995, Aug 29).
 * There should be a 30 clock cycle wait after reset, I assume this
 * has been fulfilled.
 * There should be a delay at the end equal to the longest I2C message
 * to synchronize the BB-bit (in multimaster systems). How long is
 * this? I assume 1 second is always long enough.
 *
 * vdovikin: added detect code for PCF8584
 */
static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
{
	unsigned char temp;

	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
				get_pcf(adap, 1)));

	/* S1=0x80: S0 selected, serial interface off */
	set_pcf(adap, 1, I2C_PCF_PIN);
	/*
	 * check to see S1 now used as R/W ctrl -
	 * PCF8584 does that when ESO is zero
	 */
	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
		return -ENXIO; /* definitely not PCF8584 */
	}

	/* load own address in S0, effective address is (own << 1) */
	i2c_outb(adap, get_own(adap));
	/* check it's really written */
	if ((temp = i2c_inb(adap)) != get_own(adap)) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
		return -ENXIO;
	}

	/* S1=0xA0, next byte in S2 */
	set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
	/* check to see S2 now selected */
	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
		return -ENXIO;
	}

	/* load clock register S2 */
	i2c_outb(adap, get_clock(adap));
	/* check it's really written, the only 5 lowest bits does matter */
	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
		return -ENXIO;
	}

	/* Enable serial interface, idle, S0 selected */
	set_pcf(adap, 1, I2C_PCF_IDLE);

	/* check to see PCF is really idled and we can access status register */
	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
		return -ENXIO;
	}

	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");

	return 0;
}

static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
			 int count, int last)
{
	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	int wrcount, status, timeout;

	for (wrcount=0; wrcount<count; ++wrcount) {
		DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
				buf[wrcount] & 0xff));
		i2c_outb(adap, buf[wrcount]);
		timeout = wait_for_pin(adap, &status);
		if (timeout) {
			if (timeout == -EINTR)
				return -EINTR; /* arbitration lost */

			i2c_stop(adap);
			dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
			return -EREMOTEIO; /* got a better one ?? */
		}
		if (status & I2C_PCF_LRB) {
			i2c_stop(adap);
			dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
			return -EREMOTEIO; /* got a better one ?? */
		}
	}
	if (last)
		i2c_stop(adap);
	else
		i2c_repstart(adap);

	return wrcount;
}

static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
			 int count, int last)
{
	int i, status;
	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	int wfp;

	/* increment number of bytes to read by one -- read dummy byte */
	for (i = 0; i <= count; i++) {

		if ((wfp = wait_for_pin(adap, &status))) {
			if (wfp == -EINTR)
				return -EINTR; /* arbitration lost */

			i2c_stop(adap);
			dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
			return -1;
		}

		if ((status & I2C_PCF_LRB) && (i != count)) {
			i2c_stop(adap);
			dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
			return -1;
		}

		if (i == count - 1) {
			set_pcf(adap, 1, I2C_PCF_ESO);
		} else if (i == count) {
			if (last)
				i2c_stop(adap);
			else
				i2c_repstart(adap);
		}

		if (i)
			buf[i - 1] = i2c_inb(adap);
		else
			i2c_inb(adap); /* dummy read */
	}

	return i - 1;
}


static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
			 struct i2c_msg *msg)
{
	unsigned short flags = msg->flags;
	unsigned char addr;

	addr = msg->addr << 1;
	if (flags & I2C_M_RD)
		addr |= 1;
	if (flags & I2C_M_REV_DIR_ADDR)
		addr ^= 1;
	i2c_outb(adap, addr);

	return 0;
}

static int pcf_xfer(struct i2c_adapter *i2c_adap,
		    struct i2c_msg *msgs,
		    int num)
{
	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	struct i2c_msg *pmsg;
	int i;
	int ret=0, timeout, status;

	if (adap->xfer_begin)
		adap->xfer_begin(adap->data);

	/* Check for bus busy */
	timeout = wait_for_bb(adap);
	if (timeout) {
		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
			    "Timeout waiting for BB in pcf_xfer\n");)
		i = -EIO;
		goto out;
	}

	for (i = 0;ret >= 0 && i < num; i++) {
		pmsg = &msgs[i];

		DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
		     pmsg->flags & I2C_M_RD ? "read" : "write",
		     pmsg->len, pmsg->addr, i + 1, num);)

		ret = pcf_doAddress(adap, pmsg);

		/* Send START */
		if (i == 0)
			i2c_start(adap);

		/* Wait for PIN (pending interrupt NOT) */
		timeout = wait_for_pin(adap, &status);
		if (timeout) {
			if (timeout == -EINTR) {
				/* arbitration lost */
				i = -EINTR;
				goto out;
			}
			i2c_stop(adap);
			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
				    "for PIN(1) in pcf_xfer\n");)
			i = -EREMOTEIO;
			goto out;
		}

		/* Check LRB (last rcvd bit - slave ack) */
		if (status & I2C_PCF_LRB) {
			i2c_stop(adap);
			DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
			i = -EREMOTEIO;
			goto out;
		}

		DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
			    i, msgs[i].addr, msgs[i].flags, msgs[i].len);)

		if (pmsg->flags & I2C_M_RD) {
			ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
					    (i + 1 == num));

			if (ret != pmsg->len) {
				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
					    "only read %d bytes.\n",ret));
			} else {
				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
			}
		} else {
			ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
					    (i + 1 == num));

			if (ret != pmsg->len) {
				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
					    "only wrote %d bytes.\n",ret));
			} else {
				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
			}
		}
	}

out:
	if (adap->xfer_end)
		adap->xfer_end(adap->data);
	return i;
}

static u32 pcf_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
	       I2C_FUNC_PROTOCOL_MANGLING;
}

/* exported algorithm data: */
static const struct i2c_algorithm pcf_algo = {
	.master_xfer	= pcf_xfer,
	.functionality	= pcf_func,
};

/*
 * registering functions to load algorithms at runtime
 */
int i2c_pcf_add_bus(struct i2c_adapter *adap)
{
	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
	int rval;

	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));

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

	if ((rval = pcf_init_8584(pcf_adap)))
		return rval;

	rval = i2c_add_adapter(adap);

	return rval;
}
EXPORT_SYMBOL(i2c_pcf_add_bus);

MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
MODULE_LICENSE("GPL");

module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(i2c_debug,
	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
Commit	Line	Data
0c168ceb RK	1	/*
	2	* i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters
	3	*
	4	* Copyright (C) 1995-1997 Simon G. Vogl
	5	* 1998-2000 Hans Berglund
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
0c168ceb RK	17	* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
	18	* Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
	19	* <mbailey@littlefeet-inc.com>
	20	*
	21	* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
	22	* messages, proper stop/repstart signaling during receive, added detect code
	23	*/
1da177e4 LT	24
	25	#include <linux/kernel.h>
	26	#include <linux/module.h>
	27	#include <linux/delay.h>
1da177e4 LT	28	#include <linux/errno.h>
	29	#include <linux/i2c.h>
	30	#include <linux/i2c-algo-pcf.h>
	31	#include "i2c-algo-pcf.h"
	32
	33
0c168ceb RK	34	#define DEB2(x) if (i2c_debug >= 2) x
	35	#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
	36	#define DEBPROTO(x) if (i2c_debug >= 9) x;
	37	/* debug the protocol by showing transferred bits */
1da177e4 LT	38	#define DEF_TIMEOUT 16
1da177e4 LT	39
0c168ceb RK	40	/*
0c168ceb RK	41	* module parameters:
1da177e4 LT	42	*/
	43	static int i2c_debug;
	44
0c168ceb	45	/* setting states on the bus with the right timing: */
1da177e4 LT	46
	47	#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
	48	#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
	49	#define get_own(adap) adap->getown(adap->data)
	50	#define get_clock(adap) adap->getclock(adap->data)
	51	#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
	52	#define i2c_inb(adap) adap->getpcf(adap->data, 0)
	53
0c168ceb	54	/* other auxiliary functions */
1da177e4	55
0c168ceb	56	static void i2c_start(struct i2c_algo_pcf_data *adap)
1da177e4	57	{
154d22b0	58	DEBPROTO(printk(KERN_DEBUG "S "));
1da177e4 LT	59	set_pcf(adap, 1, I2C_PCF_START);
	60	}
	61
0c168ceb	62	static void i2c_repstart(struct i2c_algo_pcf_data *adap)
1da177e4 LT	63	{
	64	DEBPROTO(printk(" Sr "));
	65	set_pcf(adap, 1, I2C_PCF_REPSTART);
	66	}
	67
0c168ceb	68	static void i2c_stop(struct i2c_algo_pcf_data *adap)
1da177e4 LT	69	{
	70	DEBPROTO(printk("P\n"));
	71	set_pcf(adap, 1, I2C_PCF_STOP);
	72	}
	73
0573d11b EB	74	static void handle_lab(struct i2c_algo_pcf_data adap, const int status)
	75	{
	76	DEB2(printk(KERN_INFO
	77	"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
0c168ceb RK	78	*status));
	79	/*
	80	* Cleanup from LAB -- reset and enable ESO.
0573d11b EB	81	* This resets the PCF8584; since we've lost the bus, no
	82	* further attempts should be made by callers to clean up
	83	* (no i2c_stop() etc.)
	84	*/
	85	set_pcf(adap, 1, I2C_PCF_PIN);
	86	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	87	/*
0c168ceb RK	88	* We pause for a time period sufficient for any running
0573d11b EB	89	* I2C transaction to complete -- the arbitration logic won't
	90	* work properly until the next START is seen.
	91	* It is assumed the bus driver or client has set a proper value.
	92	*
	93	* REVISIT: should probably use msleep instead of mdelay if we
	94	* know we can sleep.
	95	*/
	96	if (adap->lab_mdelay)
	97	mdelay(adap->lab_mdelay);
	98
	99	DEB2(printk(KERN_INFO
	100	"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
	101	get_pcf(adap, 1)));
	102	}
	103
0c168ceb RK	104	static int wait_for_bb(struct i2c_algo_pcf_data *adap)
0c168ceb RK	105	{
1da177e4 LT	106
	107	int timeout = DEF_TIMEOUT;
	108	int status;
	109
	110	status = get_pcf(adap, 1);
0c168ceb	111
94d78e18	112	while (!(status & I2C_PCF_BB) && --timeout) {
1da177e4 LT	113	udelay(100); /* wait for 100 us */
	114	status = get_pcf(adap, 1);
	115	}
0c168ceb	116
94d78e18	117	if (timeout == 0) {
1da177e4	118	printk(KERN_ERR "Timeout waiting for Bus Busy\n");
94d78e18 RK	119	return -ETIMEDOUT;
94d78e18 RK	120	}
1da177e4	121
94d78e18	122	return 0;
0c168ceb	123	}
1da177e4	124
0c168ceb RK	125	static int wait_for_pin(struct i2c_algo_pcf_data adap, int status)
0c168ceb RK	126	{
1da177e4 LT	127
	128	int timeout = DEF_TIMEOUT;
	129
	130	*status = get_pcf(adap, 1);
0c168ceb	131
94d78e18	132	while ((*status & I2C_PCF_PIN) && --timeout) {
08e5338d	133	adap->waitforpin(adap->data);
1da177e4 LT	134	*status = get_pcf(adap, 1);
	135	}
	136	if (*status & I2C_PCF_LAB) {
0573d11b	137	handle_lab(adap, status);
0c168ceb	138	return -EINTR;
1da177e4	139	}
0c168ceb	140
94d78e18 RK	141	if (timeout == 0)
	142	return -ETIMEDOUT;
	143
	144	return 0;
1da177e4 LT	145	}
1da177e4 LT	146
0c168ceb	147	/*
1da177e4 LT	148	* This should perform the 'PCF8584 initialization sequence' as described
	149	* in the Philips IC12 data book (1995, Aug 29).
	150	* There should be a 30 clock cycle wait after reset, I assume this
	151	* has been fulfilled.
	152	* There should be a delay at the end equal to the longest I2C message
	153	* to synchronize the BB-bit (in multimaster systems). How long is
	154	* this? I assume 1 second is always long enough.
	155	*
	156	* vdovikin: added detect code for PCF8584
	157	*/
	158	static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
	159	{
	160	unsigned char temp;
	161
0c168ceb RK	162	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
0c168ceb RK	163	get_pcf(adap, 1)));
1da177e4 LT	164
	165	/* S1=0x80: S0 selected, serial interface off */
	166	set_pcf(adap, 1, I2C_PCF_PIN);
0c168ceb RK	167	/*
	168	* check to see S1 now used as R/W ctrl -
	169	* PCF8584 does that when ESO is zero
	170	*/
1da177e4 LT	171	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
1da177e4 LT	172	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
7d9b48ea	173	return -ENXIO; /* definitely not PCF8584 */
1da177e4 LT	174	}
1da177e4 LT	175
0c168ceb	176	/* load own address in S0, effective address is (own << 1) */
1da177e4 LT	177	i2c_outb(adap, get_own(adap));
	178	/* check it's really written */
	179	if ((temp = i2c_inb(adap)) != get_own(adap)) {
	180	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
	181	return -ENXIO;
	182	}
	183
0c168ceb	184	/* S1=0xA0, next byte in S2 */
1da177e4 LT	185	set_pcf(adap, 1, I2C_PCF_PIN \| I2C_PCF_ES1);
	186	/* check to see S2 now selected */
	187	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
	188	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
	189	return -ENXIO;
	190	}
	191
0c168ceb	192	/* load clock register S2 */
1da177e4 LT	193	i2c_outb(adap, get_clock(adap));
	194	/* check it's really written, the only 5 lowest bits does matter */
	195	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
	196	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
	197	return -ENXIO;
	198	}
	199
0c168ceb	200	/* Enable serial interface, idle, S0 selected */
1da177e4 LT	201	set_pcf(adap, 1, I2C_PCF_IDLE);
	202
	203	/* check to see PCF is really idled and we can access status register */
	204	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN \| I2C_PCF_BB)) {
	205	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
	206	return -ENXIO;
	207	}
0c168ceb	208
a672b4c1	209	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
1da177e4 LT	210
	211	return 0;
	212	}
	213
1da177e4	214	static int pcf_sendbytes(struct i2c_adapter i2c_adap, const char buf,
0c168ceb	215	int count, int last)
1da177e4 LT	216	{
	217	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	218	int wrcount, status, timeout;
0c168ceb	219
1da177e4 LT	220	for (wrcount=0; wrcount<count; ++wrcount) {
1da177e4 LT	221	DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
0c168ceb	222	buf[wrcount] & 0xff));
1da177e4 LT	223	i2c_outb(adap, buf[wrcount]);
	224	timeout = wait_for_pin(adap, &status);
	225	if (timeout) {
0c168ceb RK	226	if (timeout == -EINTR)
	227	return -EINTR; /* arbitration lost */
	228
1da177e4 LT	229	i2c_stop(adap);
	230	dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
	231	return -EREMOTEIO; /* got a better one ?? */
	232	}
1da177e4 LT	233	if (status & I2C_PCF_LRB) {
	234	i2c_stop(adap);
	235	dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
	236	return -EREMOTEIO; /* got a better one ?? */
	237	}
1da177e4	238	}
0c168ceb	239	if (last)
1da177e4	240	i2c_stop(adap);
0c168ceb	241	else
1da177e4	242	i2c_repstart(adap);
1da177e4	243
0c168ceb	244	return wrcount;
1da177e4 LT	245	}
1da177e4 LT	246
1da177e4	247	static int pcf_readbytes(struct i2c_adapter i2c_adap, char buf,
0c168ceb	248	int count, int last)
1da177e4 LT	249	{
	250	int i, status;
	251	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	252	int wfp;
	253
	254	/* increment number of bytes to read by one -- read dummy byte */
	255	for (i = 0; i <= count; i++) {
	256
	257	if ((wfp = wait_for_pin(adap, &status))) {
0c168ceb RK	258	if (wfp == -EINTR)
	259	return -EINTR; /* arbitration lost */
	260
1da177e4 LT	261	i2c_stop(adap);
1da177e4 LT	262	dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
0c168ceb	263	return -1;
1da177e4 LT	264	}
1da177e4 LT	265
1da177e4 LT	266	if ((status & I2C_PCF_LRB) && (i != count)) {
	267	i2c_stop(adap);
	268	dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
0c168ceb	269	return -1;
1da177e4	270	}
0c168ceb	271
1da177e4 LT	272	if (i == count - 1) {
1da177e4 LT	273	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	274	} else if (i == count) {
0c168ceb RK	275	if (last)
1da177e4	276	i2c_stop(adap);
0c168ceb	277	else
1da177e4	278	i2c_repstart(adap);
0c168ceb	279	}
1da177e4	280
0c168ceb	281	if (i)
1da177e4	282	buf[i - 1] = i2c_inb(adap);
0c168ceb	283	else
1da177e4	284	i2c_inb(adap); /* dummy read */
1da177e4 LT	285	}
1da177e4 LT	286
0c168ceb	287	return i - 1;
1da177e4 LT	288	}
	289
	290
6408a833 JD	291	static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
6408a833 JD	292	struct i2c_msg *msg)
1da177e4 LT	293	{
	294	unsigned short flags = msg->flags;
	295	unsigned char addr;
6408a833 JD	296
	297	addr = msg->addr << 1;
	298	if (flags & I2C_M_RD)
	299	addr \|= 1;
	300	if (flags & I2C_M_REV_DIR_ADDR)
	301	addr ^= 1;
	302	i2c_outb(adap, addr);
	303
1da177e4 LT	304	return 0;
	305	}
	306
	307	static int pcf_xfer(struct i2c_adapter *i2c_adap,
0c168ceb	308	struct i2c_msg *msgs,
1da177e4 LT	309	int num)
	310	{
	311	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	312	struct i2c_msg *pmsg;
	313	int i;
	314	int ret=0, timeout, status;
0c168ceb	315
30091404 DM	316	if (adap->xfer_begin)
30091404 DM	317	adap->xfer_begin(adap->data);
1da177e4 LT	318
	319	/* Check for bus busy */
	320	timeout = wait_for_bb(adap);
	321	if (timeout) {
	322	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
0c168ceb	323	"Timeout waiting for BB in pcf_xfer\n");)
30091404 DM	324	i = -EIO;
30091404 DM	325	goto out;
1da177e4	326	}
0c168ceb	327
1da177e4 LT	328	for (i = 0;ret >= 0 && i < num; i++) {
	329	pmsg = &msgs[i];
	330
	331	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
	332	pmsg->flags & I2C_M_RD ? "read" : "write",
0c168ceb RK	333	pmsg->len, pmsg->addr, i + 1, num);)
0c168ceb RK	334
6408a833	335	ret = pcf_doAddress(adap, pmsg);
1da177e4 LT	336
1da177e4 LT	337	/* Send START */
0c168ceb RK	338	if (i == 0)
	339	i2c_start(adap);
	340
1da177e4 LT	341	/* Wait for PIN (pending interrupt NOT) */
	342	timeout = wait_for_pin(adap, &status);
	343	if (timeout) {
	344	if (timeout == -EINTR) {
	345	/* arbitration lost */
30091404 DM	346	i = -EINTR;
30091404 DM	347	goto out;
1da177e4 LT	348	}
	349	i2c_stop(adap);
	350	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
	351	"for PIN(1) in pcf_xfer\n");)
30091404 DM	352	i = -EREMOTEIO;
30091404 DM	353	goto out;
1da177e4	354	}
0c168ceb	355
1da177e4 LT	356	/* Check LRB (last rcvd bit - slave ack) */
	357	if (status & I2C_PCF_LRB) {
	358	i2c_stop(adap);
	359	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
30091404 DM	360	i = -EREMOTEIO;
30091404 DM	361	goto out;
1da177e4	362	}
0c168ceb	363
1da177e4 LT	364	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
1da177e4 LT	365	i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
0c168ceb	366
1da177e4	367	if (pmsg->flags & I2C_M_RD) {
1da177e4	368	ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	369	(i + 1 == num));
0c168ceb RK	370
1da177e4 LT	371	if (ret != pmsg->len) {
	372	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	373	"only read %d bytes.\n",ret));
	374	} else {
	375	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
	376	}
0c168ceb	377	} else {
1da177e4	378	ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	379	(i + 1 == num));
0c168ceb RK	380
1da177e4 LT	381	if (ret != pmsg->len) {
	382	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	383	"only wrote %d bytes.\n",ret));
	384	} else {
	385	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
	386	}
	387	}
	388	}
	389
30091404 DM	390	out:
	391	if (adap->xfer_end)
	392	adap->xfer_end(adap->data);
0c168ceb	393	return i;
1da177e4 LT	394	}
	395
	396	static u32 pcf_func(struct i2c_adapter *adap)
	397	{
0c168ceb	398	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL \|
6408a833	399	I2C_FUNC_PROTOCOL_MANGLING;
1da177e4 LT	400	}
1da177e4 LT	401
0c168ceb	402	/* exported algorithm data: */
9e11a9fb	403	static const struct i2c_algorithm pcf_algo = {
1da177e4 LT	404	.master_xfer = pcf_xfer,
	405	.functionality = pcf_func,
	406	};
	407
0c168ceb RK	408	/*
0c168ceb RK	409	* registering functions to load algorithms at runtime
1da177e4 LT	410	*/
	411	int i2c_pcf_add_bus(struct i2c_adapter *adap)
	412	{
	413	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
	414	int rval;
	415
	416	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
	417
	418	/* register new adapter to i2c module... */
1da177e4	419	adap->algo = &pcf_algo;
1da177e4	420
b39ad0cf MH	421	if ((rval = pcf_init_8584(pcf_adap)))
	422	return rval;
	423
	424	rval = i2c_add_adapter(adap);
	425
1da177e4 LT	426	return rval;
1da177e4 LT	427	}
1da177e4	428	EXPORT_SYMBOL(i2c_pcf_add_bus);
1da177e4 LT	429
	430	MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
	431	MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
	432	MODULE_LICENSE("GPL");
	433
	434	module_param(i2c_debug, int, S_IRUGO \| S_IWUSR);
	435	MODULE_PARM_DESC(i2c_debug,
0c168ceb	436	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");