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linux/drivers/i2c/algos/i2c-algo-pcf.c
Jean Delvare c7a46533ff [PATCH] I2C: Kill i2c_algorithm.id (5/7) 
Merge the algorithm id part (16 upper bits) of the i2c adapters ids
into the definition of the adapters ids directly. After that, we don't
need to OR both ids together for each i2c_adapter structure.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 09:14:31 -07:00

504 lines
14 KiB
C
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/* ------------------------------------------------------------------------- */
/* 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/slab.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("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 int wait_for_bb(struct i2c_algo_pcf_data *adap) {
int timeout = DEF_TIMEOUT;
int status;
status = get_pcf(adap, 1);
#ifndef STUB_I2C
while (timeout-- && !(status & I2C_PCF_BB)) {
udelay(100); /* wait for 100 us */
status = get_pcf(adap, 1);
}
#endif
if (timeout <= 0) {
printk(KERN_ERR "Timeout waiting for Bus Busy\n");
}
return (timeout<=0);
}
static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {
int timeout = DEF_TIMEOUT;
*status = get_pcf(adap, 1);
#ifndef STUB_I2C
while (timeout-- && (*status & I2C_PCF_PIN)) {
adap->waitforpin();
*status = get_pcf(adap, 1);
}
if (*status & I2C_PCF_LAB) {
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);
/* TODO: we should 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.
*/
DEB2(printk(KERN_INFO
"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
get_pcf(adap,1)));
return(-EINTR);
}
#endif
if (timeout <= 0)
return(-1);
else
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; /* definetly 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: deteted and initialized PCF8584.\n");
return 0;
}
/* ----- Utility functions
*/
static inline int try_address(struct i2c_algo_pcf_data *adap,
unsigned char addr, int retries)
{
int i, status, ret = -1;
int wfp;
for (i=0;i<retries;i++) {
i2c_outb(adap, addr);
i2c_start(adap);
status = get_pcf(adap, 1);
if ((wfp = wait_for_pin(adap, &status)) >= 0) {
if ((status & I2C_PCF_LRB) == 0) {
i2c_stop(adap);
break; /* success! */
}
}
if (wfp == -EINTR) {
/* arbitration lost */
udelay(adap->udelay);
return -EINTR;
}
i2c_stop(adap);
udelay(adap->udelay);
}
DEB2(if (i) printk(KERN_DEBUG "i2c-algo-pcf.o: needed %d retries for %d\n",i,
addr));
return ret;
}
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) {
/* arbitration lost */
return -EINTR;
}
i2c_stop(adap);
dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
return -EREMOTEIO; /* got a better one ?? */
}
#ifndef STUB_I2C
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 ?? */
}
#endif
}
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) {
/* arbitration lost */
return -EINTR;
}
i2c_stop(adap);
dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
return (-1);
}
#ifndef STUB_I2C
if ((status & I2C_PCF_LRB) && (i != count)) {
i2c_stop(adap);
dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
return (-1);
}
#endif
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 inline int pcf_doAddress(struct i2c_algo_pcf_data *adap,
struct i2c_msg *msg, int retries)
{
unsigned short flags = msg->flags;
unsigned char addr;
int ret;
if ( (flags & I2C_M_TEN) ) {
/* a ten bit address */
addr = 0xf0 | (( msg->addr >> 7) & 0x03);
DEB2(printk(KERN_DEBUG "addr0: %d\n",addr));
/* try extended address code...*/
ret = try_address(adap, addr, retries);
if (ret!=1) {
printk(KERN_ERR "died at extended address code.\n");
return -EREMOTEIO;
}
/* the remaining 8 bit address */
i2c_outb(adap,msg->addr & 0x7f);
/* Status check comes here */
if (ret != 1) {
printk(KERN_ERR "died at 2nd address code.\n");
return -EREMOTEIO;
}
if ( flags & I2C_M_RD ) {
i2c_repstart(adap);
/* okay, now switch into reading mode */
addr |= 0x01;
ret = try_address(adap, addr, retries);
if (ret!=1) {
printk(KERN_ERR "died at extended address code.\n");
return -EREMOTEIO;
}
}
} else { /* normal 7bit address */
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;
/* 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");)
return -EIO;
}
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, i2c_adap->retries);
/* 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 */
return (-EINTR);
}
i2c_stop(adap);
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
"for PIN(1) in pcf_xfer\n");)
return (-EREMOTEIO);
}
#ifndef STUB_I2C
/* 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");)
return (-EREMOTEIO);
}
#endif
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);)
/* Read */
if (pmsg->flags & I2C_M_RD) {
/* read bytes into buffer*/
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 { /* Write */
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));
}
}
}
return (i);
}
static u32 pcf_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
}
/* -----exported algorithm data: ------------------------------------- */
static 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;
adap->timeout = 100; /* default values, should */
adap->retries = 3; /* be replaced by defines */
rval = pcf_init_8584(pcf_adap);
if (!rval)
i2c_add_adapter(adap);
return rval;
}
int i2c_pcf_del_bus(struct i2c_adapter *adap)
{
return i2c_del_adapter(adap);
}
EXPORT_SYMBOL(i2c_pcf_add_bus);
EXPORT_SYMBOL(i2c_pcf_del_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");
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