[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.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston,
 *  MA 02110-1301 USA.
 *
 * 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/init.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	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
5694f8a8 JD	19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
5694f8a8 JD	20	* MA 02110-1301 USA.
0c168ceb RK	21	*
	22	* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
	23	* Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
	24	* <mbailey@littlefeet-inc.com>
	25	*
	26	* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
	27	* messages, proper stop/repstart signaling during receive, added detect code
	28	*/
1da177e4 LT	29
	30	#include <linux/kernel.h>
	31	#include <linux/module.h>
	32	#include <linux/delay.h>
1da177e4 LT	33	#include <linux/init.h>
	34	#include <linux/errno.h>
	35	#include <linux/i2c.h>
	36	#include <linux/i2c-algo-pcf.h>
	37	#include "i2c-algo-pcf.h"
	38
	39
0c168ceb RK	40	#define DEB2(x) if (i2c_debug >= 2) x
	41	#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
	42	#define DEBPROTO(x) if (i2c_debug >= 9) x;
	43	/* debug the protocol by showing transferred bits */
1da177e4 LT	44	#define DEF_TIMEOUT 16
1da177e4 LT	45
0c168ceb RK	46	/*
0c168ceb RK	47	* module parameters:
1da177e4 LT	48	*/
	49	static int i2c_debug;
	50
0c168ceb	51	/* setting states on the bus with the right timing: */
1da177e4 LT	52
	53	#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
	54	#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
	55	#define get_own(adap) adap->getown(adap->data)
	56	#define get_clock(adap) adap->getclock(adap->data)
	57	#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
	58	#define i2c_inb(adap) adap->getpcf(adap->data, 0)
	59
0c168ceb	60	/* other auxiliary functions */
1da177e4	61
0c168ceb	62	static void i2c_start(struct i2c_algo_pcf_data *adap)
1da177e4	63	{
154d22b0	64	DEBPROTO(printk(KERN_DEBUG "S "));
1da177e4 LT	65	set_pcf(adap, 1, I2C_PCF_START);
	66	}
	67
0c168ceb	68	static void i2c_repstart(struct i2c_algo_pcf_data *adap)
1da177e4 LT	69	{
	70	DEBPROTO(printk(" Sr "));
	71	set_pcf(adap, 1, I2C_PCF_REPSTART);
	72	}
	73
0c168ceb	74	static void i2c_stop(struct i2c_algo_pcf_data *adap)
1da177e4 LT	75	{
	76	DEBPROTO(printk("P\n"));
	77	set_pcf(adap, 1, I2C_PCF_STOP);
	78	}
	79
0573d11b EB	80	static void handle_lab(struct i2c_algo_pcf_data adap, const int status)
	81	{
	82	DEB2(printk(KERN_INFO
	83	"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
0c168ceb RK	84	*status));
	85	/*
	86	* Cleanup from LAB -- reset and enable ESO.
0573d11b EB	87	* This resets the PCF8584; since we've lost the bus, no
	88	* further attempts should be made by callers to clean up
	89	* (no i2c_stop() etc.)
	90	*/
	91	set_pcf(adap, 1, I2C_PCF_PIN);
	92	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	93	/*
0c168ceb RK	94	* We pause for a time period sufficient for any running
0573d11b EB	95	* I2C transaction to complete -- the arbitration logic won't
	96	* work properly until the next START is seen.
	97	* It is assumed the bus driver or client has set a proper value.
	98	*
	99	* REVISIT: should probably use msleep instead of mdelay if we
	100	* know we can sleep.
	101	*/
	102	if (adap->lab_mdelay)
	103	mdelay(adap->lab_mdelay);
	104
	105	DEB2(printk(KERN_INFO
	106	"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
	107	get_pcf(adap, 1)));
	108	}
	109
0c168ceb RK	110	static int wait_for_bb(struct i2c_algo_pcf_data *adap)
0c168ceb RK	111	{
1da177e4 LT	112
	113	int timeout = DEF_TIMEOUT;
	114	int status;
	115
	116	status = get_pcf(adap, 1);
0c168ceb	117
94d78e18	118	while (!(status & I2C_PCF_BB) && --timeout) {
1da177e4 LT	119	udelay(100); /* wait for 100 us */
	120	status = get_pcf(adap, 1);
	121	}
0c168ceb	122
94d78e18	123	if (timeout == 0) {
1da177e4	124	printk(KERN_ERR "Timeout waiting for Bus Busy\n");
94d78e18 RK	125	return -ETIMEDOUT;
94d78e18 RK	126	}
1da177e4	127
94d78e18	128	return 0;
0c168ceb	129	}
1da177e4	130
0c168ceb RK	131	static int wait_for_pin(struct i2c_algo_pcf_data adap, int status)
0c168ceb RK	132	{
1da177e4 LT	133
	134	int timeout = DEF_TIMEOUT;
	135
	136	*status = get_pcf(adap, 1);
0c168ceb	137
94d78e18	138	while ((*status & I2C_PCF_PIN) && --timeout) {
08e5338d	139	adap->waitforpin(adap->data);
1da177e4 LT	140	*status = get_pcf(adap, 1);
	141	}
	142	if (*status & I2C_PCF_LAB) {
0573d11b	143	handle_lab(adap, status);
0c168ceb	144	return -EINTR;
1da177e4	145	}
0c168ceb	146
94d78e18 RK	147	if (timeout == 0)
	148	return -ETIMEDOUT;
	149
	150	return 0;
1da177e4 LT	151	}
1da177e4 LT	152
0c168ceb	153	/*
1da177e4 LT	154	* This should perform the 'PCF8584 initialization sequence' as described
	155	* in the Philips IC12 data book (1995, Aug 29).
	156	* There should be a 30 clock cycle wait after reset, I assume this
	157	* has been fulfilled.
	158	* There should be a delay at the end equal to the longest I2C message
	159	* to synchronize the BB-bit (in multimaster systems). How long is
	160	* this? I assume 1 second is always long enough.
	161	*
	162	* vdovikin: added detect code for PCF8584
	163	*/
	164	static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
	165	{
	166	unsigned char temp;
	167
0c168ceb RK	168	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
0c168ceb RK	169	get_pcf(adap, 1)));
1da177e4 LT	170
	171	/* S1=0x80: S0 selected, serial interface off */
	172	set_pcf(adap, 1, I2C_PCF_PIN);
0c168ceb RK	173	/*
	174	* check to see S1 now used as R/W ctrl -
	175	* PCF8584 does that when ESO is zero
	176	*/
1da177e4 LT	177	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
1da177e4 LT	178	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
7d9b48ea	179	return -ENXIO; /* definitely not PCF8584 */
1da177e4 LT	180	}
1da177e4 LT	181
0c168ceb	182	/* load own address in S0, effective address is (own << 1) */
1da177e4 LT	183	i2c_outb(adap, get_own(adap));
	184	/* check it's really written */
	185	if ((temp = i2c_inb(adap)) != get_own(adap)) {
	186	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
	187	return -ENXIO;
	188	}
	189
0c168ceb	190	/* S1=0xA0, next byte in S2 */
1da177e4 LT	191	set_pcf(adap, 1, I2C_PCF_PIN \| I2C_PCF_ES1);
	192	/* check to see S2 now selected */
	193	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
	194	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
	195	return -ENXIO;
	196	}
	197
0c168ceb	198	/* load clock register S2 */
1da177e4 LT	199	i2c_outb(adap, get_clock(adap));
	200	/* check it's really written, the only 5 lowest bits does matter */
	201	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
	202	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
	203	return -ENXIO;
	204	}
	205
0c168ceb	206	/* Enable serial interface, idle, S0 selected */
1da177e4 LT	207	set_pcf(adap, 1, I2C_PCF_IDLE);
	208
	209	/* check to see PCF is really idled and we can access status register */
	210	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN \| I2C_PCF_BB)) {
	211	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
	212	return -ENXIO;
	213	}
0c168ceb	214
a672b4c1	215	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
1da177e4 LT	216
	217	return 0;
	218	}
	219
1da177e4	220	static int pcf_sendbytes(struct i2c_adapter i2c_adap, const char buf,
0c168ceb	221	int count, int last)
1da177e4 LT	222	{
	223	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	224	int wrcount, status, timeout;
0c168ceb	225
1da177e4 LT	226	for (wrcount=0; wrcount<count; ++wrcount) {
1da177e4 LT	227	DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
0c168ceb	228	buf[wrcount] & 0xff));
1da177e4 LT	229	i2c_outb(adap, buf[wrcount]);
	230	timeout = wait_for_pin(adap, &status);
	231	if (timeout) {
0c168ceb RK	232	if (timeout == -EINTR)
	233	return -EINTR; /* arbitration lost */
	234
1da177e4 LT	235	i2c_stop(adap);
	236	dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
	237	return -EREMOTEIO; /* got a better one ?? */
	238	}
1da177e4 LT	239	if (status & I2C_PCF_LRB) {
	240	i2c_stop(adap);
	241	dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
	242	return -EREMOTEIO; /* got a better one ?? */
	243	}
1da177e4	244	}
0c168ceb	245	if (last)
1da177e4	246	i2c_stop(adap);
0c168ceb	247	else
1da177e4	248	i2c_repstart(adap);
1da177e4	249
0c168ceb	250	return wrcount;
1da177e4 LT	251	}
1da177e4 LT	252
1da177e4	253	static int pcf_readbytes(struct i2c_adapter i2c_adap, char buf,
0c168ceb	254	int count, int last)
1da177e4 LT	255	{
	256	int i, status;
	257	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	258	int wfp;
	259
	260	/* increment number of bytes to read by one -- read dummy byte */
	261	for (i = 0; i <= count; i++) {
	262
	263	if ((wfp = wait_for_pin(adap, &status))) {
0c168ceb RK	264	if (wfp == -EINTR)
	265	return -EINTR; /* arbitration lost */
	266
1da177e4 LT	267	i2c_stop(adap);
1da177e4 LT	268	dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
0c168ceb	269	return -1;
1da177e4 LT	270	}
1da177e4 LT	271
1da177e4 LT	272	if ((status & I2C_PCF_LRB) && (i != count)) {
	273	i2c_stop(adap);
	274	dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
0c168ceb	275	return -1;
1da177e4	276	}
0c168ceb	277
1da177e4 LT	278	if (i == count - 1) {
1da177e4 LT	279	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	280	} else if (i == count) {
0c168ceb RK	281	if (last)
1da177e4	282	i2c_stop(adap);
0c168ceb	283	else
1da177e4	284	i2c_repstart(adap);
0c168ceb	285	}
1da177e4	286
0c168ceb	287	if (i)
1da177e4	288	buf[i - 1] = i2c_inb(adap);
0c168ceb	289	else
1da177e4	290	i2c_inb(adap); /* dummy read */
1da177e4 LT	291	}
1da177e4 LT	292
0c168ceb	293	return i - 1;
1da177e4 LT	294	}
	295
	296
6408a833 JD	297	static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
6408a833 JD	298	struct i2c_msg *msg)
1da177e4 LT	299	{
	300	unsigned short flags = msg->flags;
	301	unsigned char addr;
6408a833 JD	302
	303	addr = msg->addr << 1;
	304	if (flags & I2C_M_RD)
	305	addr \|= 1;
	306	if (flags & I2C_M_REV_DIR_ADDR)
	307	addr ^= 1;
	308	i2c_outb(adap, addr);
	309
1da177e4 LT	310	return 0;
	311	}
	312
	313	static int pcf_xfer(struct i2c_adapter *i2c_adap,
0c168ceb	314	struct i2c_msg *msgs,
1da177e4 LT	315	int num)
	316	{
	317	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	318	struct i2c_msg *pmsg;
	319	int i;
	320	int ret=0, timeout, status;
0c168ceb	321
30091404 DM	322	if (adap->xfer_begin)
30091404 DM	323	adap->xfer_begin(adap->data);
1da177e4 LT	324
	325	/* Check for bus busy */
	326	timeout = wait_for_bb(adap);
	327	if (timeout) {
	328	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
0c168ceb	329	"Timeout waiting for BB in pcf_xfer\n");)
30091404 DM	330	i = -EIO;
30091404 DM	331	goto out;
1da177e4	332	}
0c168ceb	333
1da177e4 LT	334	for (i = 0;ret >= 0 && i < num; i++) {
	335	pmsg = &msgs[i];
	336
	337	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
	338	pmsg->flags & I2C_M_RD ? "read" : "write",
0c168ceb RK	339	pmsg->len, pmsg->addr, i + 1, num);)
0c168ceb RK	340
6408a833	341	ret = pcf_doAddress(adap, pmsg);
1da177e4 LT	342
1da177e4 LT	343	/* Send START */
0c168ceb RK	344	if (i == 0)
	345	i2c_start(adap);
	346
1da177e4 LT	347	/* Wait for PIN (pending interrupt NOT) */
	348	timeout = wait_for_pin(adap, &status);
	349	if (timeout) {
	350	if (timeout == -EINTR) {
	351	/* arbitration lost */
30091404 DM	352	i = -EINTR;
30091404 DM	353	goto out;
1da177e4 LT	354	}
	355	i2c_stop(adap);
	356	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
	357	"for PIN(1) in pcf_xfer\n");)
30091404 DM	358	i = -EREMOTEIO;
30091404 DM	359	goto out;
1da177e4	360	}
0c168ceb	361
1da177e4 LT	362	/* Check LRB (last rcvd bit - slave ack) */
	363	if (status & I2C_PCF_LRB) {
	364	i2c_stop(adap);
	365	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
30091404 DM	366	i = -EREMOTEIO;
30091404 DM	367	goto out;
1da177e4	368	}
0c168ceb	369
1da177e4 LT	370	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
1da177e4 LT	371	i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
0c168ceb	372
1da177e4	373	if (pmsg->flags & I2C_M_RD) {
1da177e4	374	ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	375	(i + 1 == num));
0c168ceb RK	376
1da177e4 LT	377	if (ret != pmsg->len) {
	378	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	379	"only read %d bytes.\n",ret));
	380	} else {
	381	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
	382	}
0c168ceb	383	} else {
1da177e4	384	ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	385	(i + 1 == num));
0c168ceb RK	386
1da177e4 LT	387	if (ret != pmsg->len) {
	388	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	389	"only wrote %d bytes.\n",ret));
	390	} else {
	391	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
	392	}
	393	}
	394	}
	395
30091404 DM	396	out:
	397	if (adap->xfer_end)
	398	adap->xfer_end(adap->data);
0c168ceb	399	return i;
1da177e4 LT	400	}
	401
	402	static u32 pcf_func(struct i2c_adapter *adap)
	403	{
0c168ceb	404	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL \|
6408a833	405	I2C_FUNC_PROTOCOL_MANGLING;
1da177e4 LT	406	}
1da177e4 LT	407
0c168ceb	408	/* exported algorithm data: */
9e11a9fb	409	static const struct i2c_algorithm pcf_algo = {
1da177e4 LT	410	.master_xfer = pcf_xfer,
	411	.functionality = pcf_func,
	412	};
	413
0c168ceb RK	414	/*
0c168ceb RK	415	* registering functions to load algorithms at runtime
1da177e4 LT	416	*/
	417	int i2c_pcf_add_bus(struct i2c_adapter *adap)
	418	{
	419	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
	420	int rval;
	421
	422	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
	423
	424	/* register new adapter to i2c module... */
1da177e4	425	adap->algo = &pcf_algo;
1da177e4	426
b39ad0cf MH	427	if ((rval = pcf_init_8584(pcf_adap)))
	428	return rval;
	429
	430	rval = i2c_add_adapter(adap);
	431
1da177e4 LT	432	return rval;
1da177e4 LT	433	}
1da177e4	434	EXPORT_SYMBOL(i2c_pcf_add_bus);
1da177e4 LT	435
	436	MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
	437	MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
	438	MODULE_LICENSE("GPL");
	439
	440	module_param(i2c_debug, int, S_IRUGO \| S_IWUSR);
	441	MODULE_PARM_DESC(i2c_debug,
0c168ceb	442	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");