WebSVN - shark - Blame - Rev 1618 - /shark/branches/xen/drivers/i2c/algos/i2c-algo-pcf.c

Rev	Author	Line No.	Line
420	giacomo	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
		22	/* With some changes from Ky�sti M�lkki <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,
		28	added detect code */
		29
		30	/* #define DEBUG 1 / / to pick up dev_dbg calls */
		31
		32	#include <linux/kernel.h>
		33	#include <linux/module.h>
		34	#include <linux/delay.h>
		35	#include <linux/slab.h>
		36	#include <linux/init.h>
		37	#include <linux/errno.h>
		38	#include <linux/i2c.h>
		39	#include <linux/i2c-algo-pcf.h>
		40	#include "i2c-algo-pcf.h"
		41
		42
		43	/* ----- global defines ----------------------------------------------- */
		44	#define DEB(x) if (i2c_debug>=1) x
		45	#define DEB2(x) if (i2c_debug>=2) x
		46	#define DEB3(x) if (i2c_debug>=3) x /* print several statistical values*/
		47	#define DEBPROTO(x) if (i2c_debug>=9) x;
		48	/* debug the protocol by showing transferred bits */
		49	#define DEF_TIMEOUT 16
		50
		51	/* module parameters:
		52	*/
		53	static int i2c_debug=0;
		54
		55	/* --- setting states on the bus with the right timing: --------------- */
		56
		57	#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
		58	#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
		59	#define get_own(adap) adap->getown(adap->data)
		60	#define get_clock(adap) adap->getclock(adap->data)
		61	#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
		62	#define i2c_inb(adap) adap->getpcf(adap->data, 0)
		63
		64	/* --- other auxiliary functions -------------------------------------- */
		65
		66	static void i2c_start(struct i2c_algo_pcf_data *adap)
		67	{
		68	DEBPROTO(printk("S "));
		69	set_pcf(adap, 1, I2C_PCF_START);
		70	}
		71
		72	static void i2c_repstart(struct i2c_algo_pcf_data *adap)
		73	{
		74	DEBPROTO(printk(" Sr "));
		75	set_pcf(adap, 1, I2C_PCF_REPSTART);
		76	}
		77
		78
		79	static void i2c_stop(struct i2c_algo_pcf_data *adap)
		80	{
		81	DEBPROTO(printk("P\n"));
		82	set_pcf(adap, 1, I2C_PCF_STOP);
		83	}
		84
		85
		86	static int wait_for_bb(struct i2c_algo_pcf_data *adap) {
		87
		88	int timeout = DEF_TIMEOUT;
		89	int status;
		90
		91	status = get_pcf(adap, 1);
		92	#ifndef STUB_I2C
		93	while (timeout-- && !(status & I2C_PCF_BB)) {
		94	udelay(100); /* wait for 100 us */
		95	status = get_pcf(adap, 1);
		96	}
		97	#endif
		98	if (timeout <= 0) {
		99	printk(KERN_ERR "Timeout waiting for Bus Busy\n");
		100	}
		101
		102	return (timeout<=0);
		103	}
		104
		105
		106	static inline void pcf_sleep(unsigned long timeout)
		107	{
		108	schedule_timeout( timeout * HZ);
		109	}
		110
		111
		112	static int wait_for_pin(struct i2c_algo_pcf_data adap, int status) {
		113
		114	int timeout = DEF_TIMEOUT;
		115
		116	*status = get_pcf(adap, 1);
		117	#ifndef STUB_I2C
		118	while (timeout-- && (*status & I2C_PCF_PIN)) {
		119	adap->waitforpin();
		120	*status = get_pcf(adap, 1);
		121	}
		122	#endif
		123	if (timeout <= 0)
		124	return(-1);
		125	else
		126	return(0);
		127	}
		128
		129	/*
		130	* This should perform the 'PCF8584 initialization sequence' as described
		131	* in the Philips IC12 data book (1995, Aug 29).
		132	* There should be a 30 clock cycle wait after reset, I assume this
		133	* has been fulfilled.
		134	* There should be a delay at the end equal to the longest I2C message
		135	* to synchronize the BB-bit (in multimaster systems). How long is
		136	* this? I assume 1 second is always long enough.
		137	*
		138	* vdovikin: added detect code for PCF8584
		139	*/
		140	static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
		141	{
		142	unsigned char temp;
		143
		144	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n", get_pcf(adap, 1)));
		145
		146	/* S1=0x80: S0 selected, serial interface off */
		147	set_pcf(adap, 1, I2C_PCF_PIN);
		148	/* check to see S1 now used as R/W ctrl -
		149	PCF8584 does that when ESO is zero */
		150	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
		151	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
		152	return -ENXIO; /* definetly not PCF8584 */
		153	}
		154
		155	/* load own address in S0, effective address is (own << 1) */
		156	i2c_outb(adap, get_own(adap));
		157	/* check it's really written */
		158	if ((temp = i2c_inb(adap)) != get_own(adap)) {
		159	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
		160	return -ENXIO;
		161	}
		162
		163	/* S1=0xA0, next byte in S2 */
		164	set_pcf(adap, 1, I2C_PCF_PIN \| I2C_PCF_ES1);
		165	/* check to see S2 now selected */
		166	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
		167	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
		168	return -ENXIO;
		169	}
		170
		171	/* load clock register S2 */
		172	i2c_outb(adap, get_clock(adap));
		173	/* check it's really written, the only 5 lowest bits does matter */
		174	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
		175	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
		176	return -ENXIO;
		177	}
		178
		179	/* Enable serial interface, idle, S0 selected */
		180	set_pcf(adap, 1, I2C_PCF_IDLE);
		181
		182	/* check to see PCF is really idled and we can access status register */
		183	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN \| I2C_PCF_BB)) {
		184	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
		185	return -ENXIO;
		186	}
		187
		188	printk(KERN_DEBUG "i2c-algo-pcf.o: deteted and initialized PCF8584.\n");
		189
		190	return 0;
		191	}
		192
		193
		194	/* ----- Utility functions
		195	*/
		196
		197	static inline int try_address(struct i2c_algo_pcf_data *adap,
		198	unsigned char addr, int retries)
		199	{
		200	int i, status, ret = -1;
		201	for (i=0;i<retries;i++) {
		202	i2c_outb(adap, addr);
		203	i2c_start(adap);
		204	status = get_pcf(adap, 1);
		205	if (wait_for_pin(adap, &status) >= 0) {
		206	if ((status & I2C_PCF_LRB) == 0) {
		207	i2c_stop(adap);
		208	break; /* success! */
		209	}
		210	}
		211	i2c_stop(adap);
		212	udelay(adap->udelay);
		213	}
		214	DEB2(if (i) printk(KERN_DEBUG "i2c-algo-pcf.o: needed %d retries for %d\n",i,
		215	addr));
		216	return ret;
		217	}
		218
		219
		220	static int pcf_sendbytes(struct i2c_adapter i2c_adap, const char buf,
		221	int count, int last)
		222	{
		223	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
		224	int wrcount, status, timeout;
		225
		226	for (wrcount=0; wrcount<count; ++wrcount) {
		227	DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
		228	buf[wrcount]&0xff));
		229	i2c_outb(adap, buf[wrcount]);
		230	timeout = wait_for_pin(adap, &status);
		231	if (timeout) {
		232	i2c_stop(adap);
		233	dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
		234	return -EREMOTEIO; /* got a better one ?? */
		235	}
		236	#ifndef STUB_I2C
		237	if (status & I2C_PCF_LRB) {
		238	i2c_stop(adap);
		239	dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
		240	return -EREMOTEIO; /* got a better one ?? */
		241	}
		242	#endif
		243	}
		244	if (last) {
		245	i2c_stop(adap);
		246	}
		247	else {
		248	i2c_repstart(adap);
		249	}
		250
		251	return (wrcount);
		252	}
		253
		254
		255	static int pcf_readbytes(struct i2c_adapter i2c_adap, char buf,
		256	int count, int last)
		257	{
		258	int i, status;
		259	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
		260
		261	/* increment number of bytes to read by one -- read dummy byte */
		262	for (i = 0; i <= count; i++) {
		263
		264	if (wait_for_pin(adap, &status)) {
		265	i2c_stop(adap);
		266	dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
		267	return (-1);
		268	}
		269
		270	#ifndef STUB_I2C
		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");
		274	return (-1);
		275	}
		276	#endif
		277
		278	if (i == count - 1) {
		279	set_pcf(adap, 1, I2C_PCF_ESO);
		280	} else
		281	if (i == count) {
		282	if (last) {
		283	i2c_stop(adap);
		284	} else {
		285	i2c_repstart(adap);
		286	}
		287	};
		288
		289	if (i) {
		290	buf[i - 1] = i2c_inb(adap);
		291	} else {
		292	i2c_inb(adap); /* dummy read */
		293	}
		294	}
		295
		296	return (i - 1);
		297	}
		298
		299
		300	static inline int pcf_doAddress(struct i2c_algo_pcf_data *adap,
		301	struct i2c_msg *msg, int retries)
		302	{
		303	unsigned short flags = msg->flags;
		304	unsigned char addr;
		305	int ret;
		306	if ( (flags & I2C_M_TEN) ) {
		307	/* a ten bit address */
		308	addr = 0xf0 \| (( msg->addr >> 7) & 0x03);
		309	DEB2(printk(KERN_DEBUG "addr0: %d\n",addr));
		310	/* try extended address code...*/
		311	ret = try_address(adap, addr, retries);
		312	if (ret!=1) {
		313	printk(KERN_ERR "died at extended address code.\n");
		314	return -EREMOTEIO;
		315	}
		316	/* the remaining 8 bit address */
		317	i2c_outb(adap,msg->addr & 0x7f);
		318	/* Status check comes here */
		319	if (ret != 1) {
		320	printk(KERN_ERR "died at 2nd address code.\n");
		321	return -EREMOTEIO;
		322	}
		323	if ( flags & I2C_M_RD ) {
		324	i2c_repstart(adap);
		325	/* okay, now switch into reading mode */
		326	addr \|= 0x01;
		327	ret = try_address(adap, addr, retries);
		328	if (ret!=1) {
		329	printk(KERN_ERR "died at extended address code.\n");
		330	return -EREMOTEIO;
		331	}
		332	}
		333	} else { /* normal 7bit address */
		334	addr = ( msg->addr << 1 );
		335	if (flags & I2C_M_RD )
		336	addr \|= 1;
		337	if (flags & I2C_M_REV_DIR_ADDR )
		338	addr ^= 1;
		339	i2c_outb(adap, addr);
		340	}
		341	return 0;
		342	}
		343
		344	static int pcf_xfer(struct i2c_adapter *i2c_adap,
		345	struct i2c_msg msgs[],
		346	int num)
		347	{
		348	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
		349	struct i2c_msg *pmsg;
		350	int i;
		351	int ret=0, timeout, status;
		352
		353
		354	/* Check for bus busy */
		355	timeout = wait_for_bb(adap);
		356	if (timeout) {
		357	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
		358	"Timeout waiting for BB in pcf_xfer\n");)
		359	return -EIO;
		360	}
		361
		362	for (i = 0;ret >= 0 && i < num; i++) {
		363	pmsg = &msgs[i];
		364
		365	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
		366	pmsg->flags & I2C_M_RD ? "read" : "write",
		367	pmsg->len, pmsg->addr, i + 1, num);)
		368
		369	ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
		370
		371	/* Send START */
		372	if (i == 0) {
		373	i2c_start(adap);
		374	}
		375
		376	/* Wait for PIN (pending interrupt NOT) */
		377	timeout = wait_for_pin(adap, &status);
		378	if (timeout) {
		379	i2c_stop(adap);
		380	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
		381	"for PIN(1) in pcf_xfer\n");)
		382	return (-EREMOTEIO);
		383	}
		384
		385	#ifndef STUB_I2C
		386	/* Check LRB (last rcvd bit - slave ack) */
		387	if (status & I2C_PCF_LRB) {
		388	i2c_stop(adap);
		389	DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
		390	return (-EREMOTEIO);
		391	}
		392	#endif
		393
		394	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
		395	i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
		396
		397	/* Read */
		398	if (pmsg->flags & I2C_M_RD) {
		399	/* read bytes into buffer*/
		400	ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
		401	(i + 1 == num));
		402
		403	if (ret != pmsg->len) {
		404	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
		405	"only read %d bytes.\n",ret));
		406	} else {
		407	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
		408	}
		409	} else { /* Write */
		410	ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
		411	(i + 1 == num));
		412
		413	if (ret != pmsg->len) {
		414	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
		415	"only wrote %d bytes.\n",ret));
		416	} else {
		417	DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
		418	}
		419	}
		420	}
		421
		422	return (i);
		423	}
		424
		425	static u32 pcf_func(struct i2c_adapter *adap)
		426	{
		427	return I2C_FUNC_SMBUS_EMUL \| I2C_FUNC_10BIT_ADDR \|
		428	I2C_FUNC_PROTOCOL_MANGLING;
		429	}
		430
		431	/* -----exported algorithm data: ------------------------------------- */
		432
		433	static struct i2c_algorithm pcf_algo = {
		434	.name = "PCF8584 algorithm",
		435	.id = I2C_ALGO_PCF,
		436	.master_xfer = pcf_xfer,
		437	.functionality = pcf_func,
		438	};
		439
		440	/*
		441	* registering functions to load algorithms at runtime
		442	*/
		443	int i2c_pcf_add_bus(struct i2c_adapter *adap)
		444	{
		445	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
		446	int rval;
		447
		448	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
		449
		450	/* register new adapter to i2c module... */
		451
		452	adap->id \|= pcf_algo.id;
		453	adap->algo = &pcf_algo;
		454
		455	adap->timeout = 100; /* default values, should */
		456	adap->retries = 3; /* be replaced by defines */
		457
		458	rval = pcf_init_8584(pcf_adap);
		459	if (!rval)
		460	i2c_add_adapter(adap);
		461	return rval;
		462	}
		463
		464
		465	int i2c_pcf_del_bus(struct i2c_adapter *adap)
		466	{
		467	return i2c_del_adapter(adap);
		468	}
		469
		470	EXPORT_SYMBOL(i2c_pcf_add_bus);
		471	EXPORT_SYMBOL(i2c_pcf_del_bus);
		472
		473	MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
		474	MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
		475	MODULE_LICENSE("GPL");
		476
		477	MODULE_PARM(i2c_debug,"i");
		478	MODULE_PARM_DESC(i2c_debug,
		479	"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");

Subversion Repositories shark

(root)/shark/branches/xen/drivers/i2c/algos/i2c-algo-pcf.c - Rev 1618