[net-next-2.6.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., 675 Mass Ave, Cambridge, MA 02139, 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
	19	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	20	*
	21	* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
	22	* Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey
	23	* <mbailey@littlefeet-inc.com>
	24	*
	25	* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
	26	* messages, proper stop/repstart signaling during receive, added detect code
	27	*/
1da177e4 LT	28
	29	#include <linux/kernel.h>
	30	#include <linux/module.h>
	31	#include <linux/delay.h>
1da177e4 LT	32	#include <linux/init.h>
	33	#include <linux/errno.h>
	34	#include <linux/i2c.h>
	35	#include <linux/i2c-algo-pcf.h>
	36	#include "i2c-algo-pcf.h"
	37
	38
0c168ceb RK	39	#define DEB2(x) if (i2c_debug >= 2) x
	40	#define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */
	41	#define DEBPROTO(x) if (i2c_debug >= 9) x;
	42	/* debug the protocol by showing transferred bits */
1da177e4 LT	43	#define DEF_TIMEOUT 16
1da177e4 LT	44
0c168ceb RK	45	/*
0c168ceb RK	46	* module parameters:
1da177e4 LT	47	*/
	48	static int i2c_debug;
	49
0c168ceb	50	/* setting states on the bus with the right timing: */
1da177e4 LT	51
	52	#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
	53	#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
	54	#define get_own(adap) adap->getown(adap->data)
	55	#define get_clock(adap) adap->getclock(adap->data)
	56	#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
	57	#define i2c_inb(adap) adap->getpcf(adap->data, 0)
	58
0c168ceb	59	/* other auxiliary functions */
1da177e4	60
0c168ceb	61	static void i2c_start(struct i2c_algo_pcf_data *adap)
1da177e4	62	{
154d22b0	63	DEBPROTO(printk(KERN_DEBUG "S "));
1da177e4 LT	64	set_pcf(adap, 1, I2C_PCF_START);
	65	}
	66
0c168ceb	67	static void i2c_repstart(struct i2c_algo_pcf_data *adap)
1da177e4 LT	68	{
	69	DEBPROTO(printk(" Sr "));
	70	set_pcf(adap, 1, I2C_PCF_REPSTART);
	71	}
	72
0c168ceb	73	static void i2c_stop(struct i2c_algo_pcf_data *adap)
1da177e4 LT	74	{
	75	DEBPROTO(printk("P\n"));
	76	set_pcf(adap, 1, I2C_PCF_STOP);
	77	}
	78
0573d11b EB	79	static void handle_lab(struct i2c_algo_pcf_data adap, const int status)
	80	{
	81	DEB2(printk(KERN_INFO
	82	"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
0c168ceb RK	83	*status));
	84	/*
	85	* Cleanup from LAB -- reset and enable ESO.
0573d11b EB	86	* This resets the PCF8584; since we've lost the bus, no
	87	* further attempts should be made by callers to clean up
	88	* (no i2c_stop() etc.)
	89	*/
	90	set_pcf(adap, 1, I2C_PCF_PIN);
	91	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	92	/*
0c168ceb RK	93	* We pause for a time period sufficient for any running
0573d11b EB	94	* I2C transaction to complete -- the arbitration logic won't
	95	* work properly until the next START is seen.
	96	* It is assumed the bus driver or client has set a proper value.
	97	*
	98	* REVISIT: should probably use msleep instead of mdelay if we
	99	* know we can sleep.
	100	*/
	101	if (adap->lab_mdelay)
	102	mdelay(adap->lab_mdelay);
	103
	104	DEB2(printk(KERN_INFO
	105	"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
	106	get_pcf(adap, 1)));
	107	}
	108
0c168ceb RK	109	static int wait_for_bb(struct i2c_algo_pcf_data *adap)
0c168ceb RK	110	{
1da177e4 LT	111
	112	int timeout = DEF_TIMEOUT;
	113	int status;
	114
	115	status = get_pcf(adap, 1);
0c168ceb	116
94d78e18	117	while (!(status & I2C_PCF_BB) && --timeout) {
1da177e4 LT	118	udelay(100); /* wait for 100 us */
	119	status = get_pcf(adap, 1);
	120	}
0c168ceb	121
94d78e18	122	if (timeout == 0) {
1da177e4	123	printk(KERN_ERR "Timeout waiting for Bus Busy\n");
94d78e18 RK	124	return -ETIMEDOUT;
94d78e18 RK	125	}
1da177e4	126
94d78e18	127	return 0;
0c168ceb	128	}
1da177e4	129
0c168ceb RK	130	static int wait_for_pin(struct i2c_algo_pcf_data adap, int status)
0c168ceb RK	131	{
1da177e4 LT	132
	133	int timeout = DEF_TIMEOUT;
	134
	135	*status = get_pcf(adap, 1);
0c168ceb	136
94d78e18	137	while ((*status & I2C_PCF_PIN) && --timeout) {
08e5338d	138	adap->waitforpin(adap->data);
1da177e4 LT	139	*status = get_pcf(adap, 1);
	140	}
	141	if (*status & I2C_PCF_LAB) {
0573d11b	142	handle_lab(adap, status);
0c168ceb	143	return -EINTR;
1da177e4	144	}
0c168ceb	145
94d78e18 RK	146	if (timeout == 0)
	147	return -ETIMEDOUT;
	148
	149	return 0;
1da177e4 LT	150	}
1da177e4 LT	151
0c168ceb	152	/*
1da177e4 LT	153	* This should perform the 'PCF8584 initialization sequence' as described
	154	* in the Philips IC12 data book (1995, Aug 29).
	155	* There should be a 30 clock cycle wait after reset, I assume this
	156	* has been fulfilled.
	157	* There should be a delay at the end equal to the longest I2C message
	158	* to synchronize the BB-bit (in multimaster systems). How long is
	159	* this? I assume 1 second is always long enough.
	160	*
	161	* vdovikin: added detect code for PCF8584
	162	*/
	163	static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
	164	{
	165	unsigned char temp;
	166
0c168ceb RK	167	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n",
0c168ceb RK	168	get_pcf(adap, 1)));
1da177e4 LT	169
	170	/* S1=0x80: S0 selected, serial interface off */
	171	set_pcf(adap, 1, I2C_PCF_PIN);
0c168ceb RK	172	/*
	173	* check to see S1 now used as R/W ctrl -
	174	* PCF8584 does that when ESO is zero
	175	*/
1da177e4 LT	176	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
1da177e4 LT	177	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
7d9b48ea	178	return -ENXIO; /* definitely not PCF8584 */
1da177e4 LT	179	}
1da177e4 LT	180
0c168ceb	181	/* load own address in S0, effective address is (own << 1) */
1da177e4 LT	182	i2c_outb(adap, get_own(adap));
	183	/* check it's really written */
	184	if ((temp = i2c_inb(adap)) != get_own(adap)) {
	185	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
	186	return -ENXIO;
	187	}
	188
0c168ceb	189	/* S1=0xA0, next byte in S2 */
1da177e4 LT	190	set_pcf(adap, 1, I2C_PCF_PIN \| I2C_PCF_ES1);
	191	/* check to see S2 now selected */
	192	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
	193	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
	194	return -ENXIO;
	195	}
	196
0c168ceb	197	/* load clock register S2 */
1da177e4 LT	198	i2c_outb(adap, get_clock(adap));
	199	/* check it's really written, the only 5 lowest bits does matter */
	200	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
	201	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
	202	return -ENXIO;
	203	}
	204
0c168ceb	205	/* Enable serial interface, idle, S0 selected */
1da177e4 LT	206	set_pcf(adap, 1, I2C_PCF_IDLE);
	207
	208	/* check to see PCF is really idled and we can access status register */
	209	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN \| I2C_PCF_BB)) {
	210	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
	211	return -ENXIO;
	212	}
0c168ceb	213
a672b4c1	214	printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n");
1da177e4 LT	215
	216	return 0;
	217	}
	218
1da177e4	219	static int pcf_sendbytes(struct i2c_adapter i2c_adap, const char buf,
0c168ceb	220	int count, int last)
1da177e4 LT	221	{
	222	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	223	int wrcount, status, timeout;
0c168ceb	224
1da177e4 LT	225	for (wrcount=0; wrcount<count; ++wrcount) {
1da177e4 LT	226	DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
0c168ceb	227	buf[wrcount] & 0xff));
1da177e4 LT	228	i2c_outb(adap, buf[wrcount]);
	229	timeout = wait_for_pin(adap, &status);
	230	if (timeout) {
0c168ceb RK	231	if (timeout == -EINTR)
	232	return -EINTR; /* arbitration lost */
	233
1da177e4 LT	234	i2c_stop(adap);
	235	dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
	236	return -EREMOTEIO; /* got a better one ?? */
	237	}
1da177e4 LT	238	if (status & I2C_PCF_LRB) {
	239	i2c_stop(adap);
	240	dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
	241	return -EREMOTEIO; /* got a better one ?? */
	242	}
1da177e4	243	}
0c168ceb	244	if (last)
1da177e4	245	i2c_stop(adap);
0c168ceb	246	else
1da177e4	247	i2c_repstart(adap);
1da177e4	248
0c168ceb	249	return wrcount;
1da177e4 LT	250	}
1da177e4 LT	251
1da177e4	252	static int pcf_readbytes(struct i2c_adapter i2c_adap, char buf,
0c168ceb	253	int count, int last)
1da177e4 LT	254	{
	255	int i, status;
	256	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	257	int wfp;
	258
	259	/* increment number of bytes to read by one -- read dummy byte */
	260	for (i = 0; i <= count; i++) {
	261
	262	if ((wfp = wait_for_pin(adap, &status))) {
0c168ceb RK	263	if (wfp == -EINTR)
	264	return -EINTR; /* arbitration lost */
	265
1da177e4 LT	266	i2c_stop(adap);
1da177e4 LT	267	dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
0c168ceb	268	return -1;
1da177e4 LT	269	}
1da177e4 LT	270
1da177e4 LT	271	if ((status & I2C_PCF_LRB) && (i != count)) {
	272	i2c_stop(adap);
	273	dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
0c168ceb	274	return -1;
1da177e4	275	}
0c168ceb	276
1da177e4 LT	277	if (i == count - 1) {
1da177e4 LT	278	set_pcf(adap, 1, I2C_PCF_ESO);
0c168ceb RK	279	} else if (i == count) {
0c168ceb RK	280	if (last)
1da177e4	281	i2c_stop(adap);
0c168ceb	282	else
1da177e4	283	i2c_repstart(adap);
0c168ceb	284	}
1da177e4	285
0c168ceb	286	if (i)
1da177e4	287	buf[i - 1] = i2c_inb(adap);
0c168ceb	288	else
1da177e4	289	i2c_inb(adap); /* dummy read */
1da177e4 LT	290	}
1da177e4 LT	291
0c168ceb	292	return i - 1;
1da177e4 LT	293	}
	294
	295
6408a833 JD	296	static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
6408a833 JD	297	struct i2c_msg *msg)
1da177e4 LT	298	{
	299	unsigned short flags = msg->flags;
	300	unsigned char addr;
6408a833 JD	301
	302	addr = msg->addr << 1;
	303	if (flags & I2C_M_RD)
	304	addr \|= 1;
	305	if (flags & I2C_M_REV_DIR_ADDR)
	306	addr ^= 1;
	307	i2c_outb(adap, addr);
	308
1da177e4 LT	309	return 0;
	310	}
	311
	312	static int pcf_xfer(struct i2c_adapter *i2c_adap,
0c168ceb	313	struct i2c_msg *msgs,
1da177e4 LT	314	int num)
	315	{
	316	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	317	struct i2c_msg *pmsg;
	318	int i;
	319	int ret=0, timeout, status;
0c168ceb	320
30091404 DM	321	if (adap->xfer_begin)
30091404 DM	322	adap->xfer_begin(adap->data);
1da177e4 LT	323
	324	/* Check for bus busy */
	325	timeout = wait_for_bb(adap);
	326	if (timeout) {
	327	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
0c168ceb	328	"Timeout waiting for BB in pcf_xfer\n");)
30091404 DM	329	i = -EIO;
30091404 DM	330	goto out;
1da177e4	331	}
0c168ceb	332
1da177e4 LT	333	for (i = 0;ret >= 0 && i < num; i++) {
	334	pmsg = &msgs[i];
	335
	336	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
	337	pmsg->flags & I2C_M_RD ? "read" : "write",
0c168ceb RK	338	pmsg->len, pmsg->addr, i + 1, num);)
0c168ceb RK	339
6408a833	340	ret = pcf_doAddress(adap, pmsg);
1da177e4 LT	341
1da177e4 LT	342	/* Send START */
0c168ceb RK	343	if (i == 0)
	344	i2c_start(adap);
	345
1da177e4 LT	346	/* Wait for PIN (pending interrupt NOT) */
	347	timeout = wait_for_pin(adap, &status);
	348	if (timeout) {
	349	if (timeout == -EINTR) {
	350	/* arbitration lost */
30091404 DM	351	i = -EINTR;
30091404 DM	352	goto out;
1da177e4 LT	353	}
	354	i2c_stop(adap);
	355	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
	356	"for PIN(1) in pcf_xfer\n");)
30091404 DM	357	i = -EREMOTEIO;
30091404 DM	358	goto out;
1da177e4	359	}
0c168ceb	360
1da177e4 LT	361	/* Check LRB (last rcvd bit - slave ack) */
	362	if (status & I2C_PCF_LRB) {
	363	i2c_stop(adap);
	364	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
30091404 DM	365	i = -EREMOTEIO;
30091404 DM	366	goto out;
1da177e4	367	}
0c168ceb	368
1da177e4 LT	369	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
1da177e4 LT	370	i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
0c168ceb	371
1da177e4	372	if (pmsg->flags & I2C_M_RD) {
1da177e4	373	ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	374	(i + 1 == num));
0c168ceb RK	375
1da177e4 LT	376	if (ret != pmsg->len) {
	377	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	378	"only read %d bytes.\n",ret));
	379	} else {
	380	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
	381	}
0c168ceb	382	} else {
1da177e4	383	ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
0c168ceb RK	384	(i + 1 == num));
0c168ceb RK	385
1da177e4 LT	386	if (ret != pmsg->len) {
	387	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
	388	"only wrote %d bytes.\n",ret));
	389	} else {
	390	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
	391	}
	392	}
	393	}
	394
30091404 DM	395	out:
	396	if (adap->xfer_end)
	397	adap->xfer_end(adap->data);
0c168ceb	398	return i;
1da177e4 LT	399	}
	400
	401	static u32 pcf_func(struct i2c_adapter *adap)
	402	{
0c168ceb	403	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL \|
6408a833	404	I2C_FUNC_PROTOCOL_MANGLING;
1da177e4 LT	405	}
1da177e4 LT	406
0c168ceb	407	/* exported algorithm data: */
9e11a9fb	408	static const struct i2c_algorithm pcf_algo = {
1da177e4 LT	409	.master_xfer = pcf_xfer,
	410	.functionality = pcf_func,
	411	};
	412
0c168ceb RK	413	/*
0c168ceb RK	414	* registering functions to load algorithms at runtime
1da177e4 LT	415	*/
	416	int i2c_pcf_add_bus(struct i2c_adapter *adap)
	417	{
	418	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
	419	int rval;
	420
	421	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
	422
	423	/* register new adapter to i2c module... */
1da177e4	424	adap->algo = &pcf_algo;
1da177e4	425
b39ad0cf MH	426	if ((rval = pcf_init_8584(pcf_adap)))
	427	return rval;
	428
	429	rval = i2c_add_adapter(adap);
	430
1da177e4 LT	431	return rval;
1da177e4 LT	432	}
1da177e4	433	EXPORT_SYMBOL(i2c_pcf_add_bus);
1da177e4 LT	434
	435	MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
	436	MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
	437	MODULE_LICENSE("GPL");
	438
	439	module_param(i2c_debug, int, S_IRUGO \| S_IWUSR);
	440	MODULE_PARM_DESC(i2c_debug,
0c168ceb	441	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");