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kernel-fxtec-pro1x/drivers/i2c/algos/i2c-algo-pca.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

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/*
* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
* Copyright (C) 2004 Arcom Control Systems
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.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-pca.h>
#include "i2c-algo-pca.h"
#define DRIVER "i2c-algo-pca"
#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)
static int i2c_debug=0;
#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
#define pca_inw(adap, reg) adap->read_byte(adap, reg)
#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
#define pca_clock(adap) adap->get_clock(adap)
#define pca_own(adap) adap->get_own(adap)
#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
#define pca_wait(adap) adap->wait_for_interrupt(adap)
/*
* Generate a start condition on the i2c bus.
*
* returns after the start condition has occurred
*/
static void pca_start(struct i2c_algo_pca_data *adap)
{
int sta = pca_get_con(adap);
DEB2("=== START\n");
sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
pca_wait(adap);
}
/*
* Generate a repeated start condition on the i2c bus
*
* return after the repeated start condition has occurred
*/
static void pca_repeated_start(struct i2c_algo_pca_data *adap)
{
int sta = pca_get_con(adap);
DEB2("=== REPEATED START\n");
sta |= I2C_PCA_CON_STA;
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
pca_wait(adap);
}
/*
* Generate a stop condition on the i2c bus
*
* returns after the stop condition has been generated
*
* STOPs do not generate an interrupt or set the SI flag, since the
* part returns the idle state (0xf8). Hence we don't need to
* pca_wait here.
*/
static void pca_stop(struct i2c_algo_pca_data *adap)
{
int sta = pca_get_con(adap);
DEB2("=== STOP\n");
sta |= I2C_PCA_CON_STO;
sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
}
/*
* Send the slave address and R/W bit
*
* returns after the address has been sent
*/
static void pca_address(struct i2c_algo_pca_data *adap,
struct i2c_msg *msg)
{
int sta = pca_get_con(adap);
int addr;
addr = ( (0x7f & msg->addr) << 1 );
if (msg->flags & I2C_M_RD )
addr |= 1;
DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
pca_outw(adap, I2C_PCA_DAT, addr);
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
pca_wait(adap);
}
/*
* Transmit a byte.
*
* Returns after the byte has been transmitted
*/
static void pca_tx_byte(struct i2c_algo_pca_data *adap,
__u8 b)
{
int sta = pca_get_con(adap);
DEB2("=== WRITE %#04x\n", b);
pca_outw(adap, I2C_PCA_DAT, b);
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
pca_set_con(adap, sta);
pca_wait(adap);
}
/*
* Receive a byte
*
* returns immediately.
*/
static void pca_rx_byte(struct i2c_algo_pca_data *adap,
__u8 *b, int ack)
{
*b = pca_inw(adap, I2C_PCA_DAT);
DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
}
/*
* Setup ACK or NACK for next received byte and wait for it to arrive.
*
* Returns after next byte has arrived.
*/
static void pca_rx_ack(struct i2c_algo_pca_data *adap,
int ack)
{
int sta = pca_get_con(adap);
sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);
if ( ack )
sta |= I2C_PCA_CON_AA;
pca_set_con(adap, sta);
pca_wait(adap);
}
/*
* Reset the i2c bus / SIO
*/
static void pca_reset(struct i2c_algo_pca_data *adap)
{
/* apparently only an external reset will do it. not a lot can be done */
printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
}
static int pca_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg *msgs,
int num)
{
struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
struct i2c_msg *msg = NULL;
int curmsg;
int numbytes = 0;
int state;
int ret;
int timeout = 100;
while ((state = pca_status(adap)) != 0xf8 && timeout--) {
msleep(10);
}
if (state != 0xf8) {
dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state);
return -EIO;
}
DEB1("{{{ XFER %d messages\n", num);
if (i2c_debug>=2) {
for (curmsg = 0; curmsg < num; curmsg++) {
int addr, i;
msg = &msgs[curmsg];
addr = (0x7f & msg->addr) ;
if (msg->flags & I2C_M_RD )
printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
curmsg, msg->len, addr, (addr<<1) | 1);
else {
printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
curmsg, msg->len, addr, addr<<1,
msg->len == 0 ? "" : ", ");
for(i=0; i < msg->len; i++)
printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
printk("]\n");
}
}
}
curmsg = 0;
ret = -EREMOTEIO;
while (curmsg < num) {
state = pca_status(adap);
DEB3("STATE is 0x%02x\n", state);
msg = &msgs[curmsg];
switch (state) {
case 0xf8: /* On reset or stop the bus is idle */
pca_start(adap);
break;
case 0x08: /* A START condition has been transmitted */
case 0x10: /* A repeated start condition has been transmitted */
pca_address(adap, msg);
break;
case 0x18: /* SLA+W has been transmitted; ACK has been received */
case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
if (numbytes < msg->len) {
pca_tx_byte(adap, msg->buf[numbytes]);
numbytes++;
break;
}
curmsg++; numbytes = 0;
if (curmsg == num)
pca_stop(adap);
else
pca_repeated_start(adap);
break;
case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
DEB2("NOT ACK received after SLA+W\n");
pca_stop(adap);
goto out;
case 0x40: /* SLA+R has been transmitted; ACK has been received */
pca_rx_ack(adap, msg->len > 1);
break;
case 0x50: /* Data bytes has been received; ACK has been returned */
if (numbytes < msg->len) {
pca_rx_byte(adap, &msg->buf[numbytes], 1);
numbytes++;
pca_rx_ack(adap, numbytes < msg->len - 1);
break;
}
curmsg++; numbytes = 0;
if (curmsg == num)
pca_stop(adap);
else
pca_repeated_start(adap);
break;
case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
DEB2("NOT ACK received after SLA+R\n");
pca_stop(adap);
goto out;
case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
DEB2("NOT ACK received after data byte\n");
goto out;
case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
DEB2("Arbitration lost\n");
goto out;
case 0x58: /* Data byte has been received; NOT ACK has been returned */
if ( numbytes == msg->len - 1 ) {
pca_rx_byte(adap, &msg->buf[numbytes], 0);
curmsg++; numbytes = 0;
if (curmsg == num)
pca_stop(adap);
else
pca_repeated_start(adap);
} else {
DEB2("NOT ACK sent after data byte received. "
"Not final byte. numbytes %d. len %d\n",
numbytes, msg->len);
pca_stop(adap);
goto out;
}
break;
case 0x70: /* Bus error - SDA stuck low */
DEB2("BUS ERROR - SDA Stuck low\n");
pca_reset(adap);
goto out;
case 0x90: /* Bus error - SCL stuck low */
DEB2("BUS ERROR - SCL Stuck low\n");
pca_reset(adap);
goto out;
case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
DEB2("BUS ERROR - Illegal START or STOP\n");
pca_reset(adap);
goto out;
default:
printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
break;
}
}
ret = curmsg;
out:
DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
"status is %#04x. control is %#04x\n",
curmsg, num, pca_status(adap),
pca_get_con(adap));
return ret;
}
static u32 pca_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static int pca_init(struct i2c_algo_pca_data *adap)
{
static int freqs[] = {330,288,217,146,88,59,44,36};
int own, clock;
own = pca_own(adap);
clock = pca_clock(adap);
DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
pca_outw(adap, I2C_PCA_ADR, own << 1);
pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
udelay(500); /* 500 <20>s for oscilator to stabilise */
return 0;
}
static struct i2c_algorithm pca_algo = {
.master_xfer = pca_xfer,
.functionality = pca_func,
};
/*
* registering functions to load algorithms at runtime
*/
int i2c_pca_add_bus(struct i2c_adapter *adap)
{
struct i2c_algo_pca_data *pca_adap = adap->algo_data;
int rval;
/* register new adapter to i2c module... */
adap->algo = &pca_algo;
adap->timeout = 100; /* default values, should */
adap->retries = 3; /* be replaced by defines */
rval = pca_init(pca_adap);
if (!rval)
i2c_add_adapter(adap);
return rval;
}
int i2c_pca_del_bus(struct i2c_adapter *adap)
{
return i2c_del_adapter(adap);
}
EXPORT_SYMBOL(i2c_pca_add_bus);
EXPORT_SYMBOL(i2c_pca_del_bus);
MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
MODULE_LICENSE("GPL");
module_param(i2c_debug, int, 0);
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