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/*
* $Id: saa7134-i2c.c,v 1.22 2005/07/22 04:09:41 mkrufky Exp $
*
* device driver for philips saa7134 based TV cards
* i2c interface support
*
* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
*
* 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/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include "saa7134-reg.h"
#include "saa7134.h"
/* ----------------------------------------------------------- */
static unsigned int i2c_debug = 0;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
static unsigned int i2c_scan = 0;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
#define d1printk if (1 == i2c_debug) printk
#define d2printk if (2 == i2c_debug) printk
#define I2C_WAIT_DELAY 32
#define I2C_WAIT_RETRY 16
/* ----------------------------------------------------------- */
static char *str_i2c_status[] = {
"IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
"DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
"NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
};
enum i2c_status {
IDLE = 0, // no I2C command pending
DONE_STOP = 1, // I2C command done and STOP executed
BUSY = 2, // executing I2C command
TO_SCL = 3, // executing I2C command, time out on clock stretching
TO_ARB = 4, // time out on arbitration trial, still trying
DONE_WRITE = 5, // I2C command done and awaiting next write command
DONE_READ = 6, // I2C command done and awaiting next read command
DONE_WRITE_TO = 7, // see 5, and time out on status echo
DONE_READ_TO = 8, // see 6, and time out on status echo
NO_DEVICE = 9, // no acknowledge on device slave address
NO_ACKN = 10, // no acknowledge after data byte transfer
BUS_ERR = 11, // bus error
ARB_LOST = 12, // arbitration lost during transfer
SEQ_ERR = 13, // erroneous programming sequence
ST_ERR = 14, // wrong status echoing
SW_ERR = 15 // software error
};
static char *str_i2c_attr[] = {
"NOP", "STOP", "CONTINUE", "START"
};
enum i2c_attr {
NOP = 0, // no operation on I2C bus
STOP = 1, // stop condition, no associated byte transfer
CONTINUE = 2, // continue with byte transfer
START = 3 // start condition with byte transfer
};
static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
{
enum i2c_status status;
status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
d2printk(KERN_DEBUG "%s: i2c stat <= %s\n",dev->name,
str_i2c_status[status]);
return status;
}
static inline void i2c_set_status(struct saa7134_dev *dev,
enum i2c_status status)
{
d2printk(KERN_DEBUG "%s: i2c stat => %s\n",dev->name,
str_i2c_status[status]);
saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
}
static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
{
d2printk(KERN_DEBUG "%s: i2c attr => %s\n",dev->name,
str_i2c_attr[attr]);
saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
}
static inline int i2c_is_error(enum i2c_status status)
{
switch (status) {
case NO_DEVICE:
case NO_ACKN:
case BUS_ERR:
case ARB_LOST:
case SEQ_ERR:
case ST_ERR:
return TRUE;
default:
return FALSE;
}
}
static inline int i2c_is_idle(enum i2c_status status)
{
switch (status) {
case IDLE:
case DONE_STOP:
return TRUE;
default:
return FALSE;
}
}
static inline int i2c_is_busy(enum i2c_status status)
{
switch (status) {
case BUSY:
return TRUE;
default:
return FALSE;
}
}
static int i2c_is_busy_wait(struct saa7134_dev *dev)
{
enum i2c_status status;
int count;
for (count = 0; count < I2C_WAIT_RETRY; count++) {
status = i2c_get_status(dev);
if (!i2c_is_busy(status))
break;
saa_wait(I2C_WAIT_DELAY);
}
if (I2C_WAIT_RETRY == count)
return FALSE;
return TRUE;
}
static int i2c_reset(struct saa7134_dev *dev)
{
enum i2c_status status;
int count;
d2printk(KERN_DEBUG "%s: i2c reset\n",dev->name);
status = i2c_get_status(dev);
if (!i2c_is_error(status))
return TRUE;
i2c_set_status(dev,status);
for (count = 0; count < I2C_WAIT_RETRY; count++) {
status = i2c_get_status(dev);
if (!i2c_is_error(status))
break;
udelay(I2C_WAIT_DELAY);
}
if (I2C_WAIT_RETRY == count)
return FALSE;
if (!i2c_is_idle(status))
return FALSE;
i2c_set_attr(dev,NOP);
return TRUE;
}
static inline int i2c_send_byte(struct saa7134_dev *dev,
enum i2c_attr attr,
unsigned char data)
{
enum i2c_status status;
__u32 dword;
/* have to write both attr + data in one 32bit word */
dword = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
dword &= 0x0f;
dword |= (attr << 6);
dword |= ((__u32)data << 8);
dword |= 0x00 << 16; /* 100 kHz */
// dword |= 0x40 << 16; /* 400 kHz */
dword |= 0xf0 << 24;
saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
d2printk(KERN_DEBUG "%s: i2c data => 0x%x\n",dev->name,data);
if (!i2c_is_busy_wait(dev))
return -EIO;
status = i2c_get_status(dev);
if (i2c_is_error(status))
return -EIO;
return 0;
}
static inline int i2c_recv_byte(struct saa7134_dev *dev)
{
enum i2c_status status;
unsigned char data;
i2c_set_attr(dev,CONTINUE);
if (!i2c_is_busy_wait(dev))
return -EIO;
status = i2c_get_status(dev);
if (i2c_is_error(status))
return -EIO;
data = saa_readb(SAA7134_I2C_DATA);
d2printk(KERN_DEBUG "%s: i2c data <= 0x%x\n",dev->name,data);
return data;
}
static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg *msgs, int num)
{
struct saa7134_dev *dev = i2c_adap->algo_data;
enum i2c_status status;
unsigned char data;
int addr,rc,i,byte;
status = i2c_get_status(dev);
if (!i2c_is_idle(status))
if (!i2c_reset(dev))
return -EIO;
d2printk("start xfer\n");
d1printk(KERN_DEBUG "%s: i2c xfer:",dev->name);
for (i = 0; i < num; i++) {
if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
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