linux/drivers/media/video/saa7134/saa7134-i2c.c
Michael Krufky b9dcdb6fb8 V4L/DVB (11860): saa7134: fix quirk in saa7134_i2c_xfer for the saa7131 bridge
The i2c quirk in the saa7134_i2c_xfer function does a bogus write
to i2c address 0xfd, to work around a bug in the silicon that
affects read transactions.

Unfortunately, this hack is not working properly, since the bogus
write is to 0xfd, an invalid i2c address.  Fix this quirk by using
an actual valid i2c address, 0xfe, which is still unlikely to be
used as an i2c address for any actual i2c client.

This is required in order to properly communicate with a TDA10048
DVB-T demod located at i2c address 0x10 on the primary i2c bus.

Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-06-16 18:21:14 -03:00

426 lines
11 KiB
C

/*
*
* 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/kernel.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include "saa7134-reg.h"
#include "saa7134.h"
#include <media/v4l2-common.h>
/* ----------------------------------------------------------- */
static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
static unsigned int i2c_scan;
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:
case TO_SCL:
case TO_ARB:
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) {
/* send address */
d2printk("send address\n");
addr = msgs[i].addr << 1;
if (msgs[i].flags & I2C_M_RD)
addr |= 1;
if (i > 0 && msgs[i].flags & I2C_M_RD && msgs[i].addr != 0x40) {
/* workaround for a saa7134 i2c bug
* needed to talk to the mt352 demux
* thanks to pinnacle for the hint */
int quirk = 0xfe;
d1printk(" [%02x quirk]",quirk);
i2c_send_byte(dev,START,quirk);
i2c_recv_byte(dev);
}
d1printk(" < %02x", addr);
rc = i2c_send_byte(dev,START,addr);
if (rc < 0)
goto err;
}
if (msgs[i].flags & I2C_M_RD) {
/* read bytes */
d2printk("read bytes\n");
for (byte = 0; byte < msgs[i].len; byte++) {
d1printk(" =");
rc = i2c_recv_byte(dev);
if (rc < 0)
goto err;
d1printk("%02x", rc);
msgs[i].buf[byte] = rc;
}
} else {
/* write bytes */
d2printk("write bytes\n");
for (byte = 0; byte < msgs[i].len; byte++) {
data = msgs[i].buf[byte];
d1printk(" %02x", data);
rc = i2c_send_byte(dev,CONTINUE,data);
if (rc < 0)
goto err;
}
}
}
d2printk("xfer done\n");
d1printk(" >");
i2c_set_attr(dev,STOP);
rc = -EIO;
if (!i2c_is_busy_wait(dev))
goto err;
status = i2c_get_status(dev);
if (i2c_is_error(status))
goto err;
/* ensure that the bus is idle for at least one bit slot */
msleep(1);
d1printk("\n");
return num;
err:
if (1 == i2c_debug) {
status = i2c_get_status(dev);
printk(" ERROR: %s\n",str_i2c_status[status]);
}
return rc;
}
/* ----------------------------------------------------------- */
static u32 functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL;
}
static struct i2c_algorithm saa7134_algo = {
.master_xfer = saa7134_i2c_xfer,
.functionality = functionality,
};
static struct i2c_adapter saa7134_adap_template = {
.owner = THIS_MODULE,
.name = "saa7134",
.id = I2C_HW_SAA7134,
.algo = &saa7134_algo,
};
static struct i2c_client saa7134_client_template = {
.name = "saa7134 internal",
};
/* ----------------------------------------------------------- */
static int
saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
{
unsigned char buf;
int i,err;
dev->i2c_client.addr = 0xa0 >> 1;
buf = 0;
if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
dev->name,err);
return -1;
}
if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
printk(KERN_WARNING "%s: i2c eeprom read error (err=%d)\n",
dev->name,err);
return -1;
}
for (i = 0; i < len; i++) {
if (0 == (i % 16))
printk(KERN_INFO "%s: i2c eeprom %02x:",dev->name,i);
printk(" %02x",eedata[i]);
if (15 == (i % 16))
printk("\n");
}
return 0;
}
static char *i2c_devs[128] = {
[ 0x20 ] = "mpeg encoder (saa6752hs)",
[ 0xa0 >> 1 ] = "eeprom",
[ 0xc0 >> 1 ] = "tuner (analog)",
[ 0x86 >> 1 ] = "tda9887",
[ 0x5a >> 1 ] = "remote control",
};
static void do_i2c_scan(char *name, struct i2c_client *c)
{
unsigned char buf;
int i,rc;
for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
c->addr = i;
rc = i2c_master_recv(c,&buf,0);
if (rc < 0)
continue;
printk("%s: i2c scan: found device @ 0x%x [%s]\n",
name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
}
}
int saa7134_i2c_register(struct saa7134_dev *dev)
{
dev->i2c_adap = saa7134_adap_template;
dev->i2c_adap.dev.parent = &dev->pci->dev;
strcpy(dev->i2c_adap.name,dev->name);
dev->i2c_adap.algo_data = dev;
i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
i2c_add_adapter(&dev->i2c_adap);
dev->i2c_client = saa7134_client_template;
dev->i2c_client.adapter = &dev->i2c_adap;
saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
if (i2c_scan)
do_i2c_scan(dev->name,&dev->i2c_client);
/* Instantiate the IR receiver device, if present */
saa7134_probe_i2c_ir(dev);
return 0;
}
int saa7134_i2c_unregister(struct saa7134_dev *dev)
{
i2c_del_adapter(&dev->i2c_adap);
return 0;
}
/* ----------------------------------------------------------- */
/*
* Local variables:
* c-basic-offset: 8
* End:
*/