- 根目录:
- drivers
- media
- video
- em28xx
- em28xx-i2c.c
/*
em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
Markus Rechberger <mrechberger@gmail.com>
Mauro Carvalho Chehab <mchehab@infradead.org>
Sascha Sommer <saschasommer@freenet.de>
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/module.h>
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/i2c.h>
#include "em28xx.h"
#include "tuner-xc2028.h"
#include <media/v4l2-common.h>
#include <media/tuner.h>
/* ----------------------------------------------------------- */
static unsigned int i2c_scan;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
#define dprintk1(lvl, fmt, args...) \
do { \
if (i2c_debug >= lvl) { \
printk(fmt, ##args); \
} \
} while (0)
#define dprintk2(lvl, fmt, args...) \
do { \
if (i2c_debug >= lvl) { \
printk(KERN_DEBUG "%s at %s: " fmt, \
dev->name, __func__ , ##args); \
} \
} while (0)
/*
* em2800_i2c_send_max4()
* send up to 4 bytes to the i2c device
*/
static int em2800_i2c_send_max4(struct em28xx *dev, unsigned char addr,
char *buf, int len)
{
int ret;
int write_timeout;
unsigned char b2[6];
BUG_ON(len < 1 || len > 4);
b2[5] = 0x80 + len - 1;
b2[4] = addr;
b2[3] = buf[0];
if (len > 1)
b2[2] = buf[1];
if (len > 2)
b2[1] = buf[2];
if (len > 3)
b2[0] = buf[3];
ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
if (ret != 2 + len) {
em28xx_warn("writing to i2c device failed (error=%i)\n", ret);
return -EIO;
}
for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
write_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05);
if (ret == 0x80 + len - 1)
return len;
msleep(5);
}
em28xx_warn("i2c write timed out\n");
return -EIO;
}
/*
* em2800_i2c_send_bytes()
*/
static int em2800_i2c_send_bytes(void *data, unsigned char addr, char *buf,
short len)
{
char *bufPtr = buf;
int ret;
int wrcount = 0;
int count;
int maxLen = 4;
struct em28xx *dev = (struct em28xx *)data;
while (len > 0) {
count = (len > maxLen) ? maxLen : len;
ret = em2800_i2c_send_max4(dev, addr, bufPtr, count);
if (ret > 0) {
len -= count;
bufPtr += count;
wrcount += count;
} else
return (ret < 0) ? ret : -EFAULT;
}
return wrcount;
}
/*
* em2800_i2c_check_for_device()
* check if there is a i2c_device at the supplied address
*/
static int em2800_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
{
char msg;
int ret;
int write_timeout;
msg = addr;
ret = dev->em28xx_write_regs(dev, 0x04, &msg, 1);
if (ret < 0) {
em28xx_warn("setting i2c device address failed (error=%i)\n",
ret);
return ret;
}
msg = 0x84;
ret = dev->em28xx_write_regs(dev, 0x05, &msg, 1);
if (ret < 0) {
em28xx_warn("preparing i2c read failed (error=%i)\n", ret);
return ret;
}
for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
write_timeout -= 5) {
unsigned reg = dev->em28xx_read_reg(dev, 0x5);
if (reg == 0x94)
return -ENODEV;
else if (reg == 0x84)
return 0;
msleep(5);
}
return -ENODEV;
}
/*
* em2800_i2c_recv_bytes()
* read from the i2c device
*/
static int em2800_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
char *buf, int len)
{
int ret;
/* check for the device and set i2c read address */
ret = em2800_i2c_check_for_device(dev, addr);
if (ret) {
em28xx_warn
("preparing read at i2c address 0x%x failed (error=%i)\n",
addr, ret);
return ret;
}
ret = dev->em28xx_read_reg_req_len(dev, 0x0, 0x3, buf, len);
if (ret < 0) {
em28xx_warn("reading from i2c device at 0x%x failed (error=%i)",
addr, ret);
return ret;
}
return ret;
}
/*
* em28xx_i2c_send_bytes()
* untested for more than 4 bytes
*/
static int em28xx_i2c_send_bytes(void *data, unsigned char addr, char *buf,
short len, int stop)
{
int wrcount = 0;
struct em28xx *dev = (struct em28xx *)data;
wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
return wrcount;
}
/*
* em28xx_i2c_recv_bytes()
* read a byte from the i2c device
*/
static int em28xx_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
char *buf, int len)
{
int ret;
ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
if (ret < 0) {
em28xx_warn("reading i2c device failed (error=%i)\n", ret);
return ret;
}
if (dev->em28xx_read_reg(dev, 0x5) != 0)
return -ENODEV;
return ret;
}
/*
* em28xx_i2c_check_for_device()
* check if there is a i2c_device at the supplied address
*/
static int em28xx_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
{
char msg;
int ret;
msg = addr;
ret = dev->em28xx_read_reg_req(dev, 2, addr);
if (ret < 0) {
em28xx_warn("reading from i2c device failed (error=%i)\n", ret);
return ret;
}
if (dev->em28xx_read_reg(dev, 0x5) != 0)
return -ENODEV;
return 0;
}
/*
* em28xx_i2c_xfer()
* the main i2c transfer function
*/
static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg msgs[], int num)
{
struct em28xx *dev = i2c_adap->algo_data;
int addr, rc, i, byte;
if (num <= 0)
return 0;
for (i = 0; i < num; i++) {
addr = msgs[i].addr << 1;
dprintk2(2, "%s %s addr=%x len=%d:",
(msgs[i].flags & I2C_M_RD) ? "read" : "write",
i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len);
if (!msgs[i].len) { /* no len: check only for device presence */
if (dev->board.is_em2800)
rc = em2800_i2c_check_for_device(dev, addr);
else
rc = em28xx_i2c_check_for_device(dev, addr);
if (rc < 0) {
dprintk2(2, " no device\n");
return rc;
}
} else if (msgs[i].flags & I2C_M_RD) {
/* read bytes */
if (dev->board.is_em2800)
rc = em2800_i2c_recv_bytes(dev, addr,
msgs[i].buf,
msgs[i].len);
else
rc = em28xx_i2c_recv_bytes(dev, addr,
msgs[i].buf,
msgs[i].len);
if (i2c_debug >= 2) {
for (byte = 0; byte < msgs[i].len; byte++)
printk(" %02x", msgs[i].buf[byte]);
}
} else {
/* write bytes */
if (i2c_debug >= 2) {
for (byte = 0; byte < msgs[i].len; byte++)
printk(" %02x", msgs[i].buf[byte]);
}
if (dev->board.is_em2800)
rc = em2800_i2c_send_bytes(dev, addr,
msgs[i].buf,
msgs[i].len);
else
rc = em28xx_i2c_send_bytes(dev, addr,
msgs[i].buf,
msgs[i].len,
i == num - 1);
}
if (rc < 0)
goto err;
if (i2c_debug >= 2)
printk("\n");
}
return num;
err:
dprintk2(2, " ERROR: %i\n", rc);
return rc;
}
/* based on linux/sunrpc/svcauth.h and linux/hash.h
* The original hash function returns a different value, if arch is x86_64
* or i386.
*/
static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
{
unsigned long hash = 0;
unsigned long l = 0;
int len = 0;
unsigned char c;
do {
if (len == length) {
c = (char)len;
len = -1;
} else
c = *buf++;
l = (l << 8) | c;
len++;
if ((len & (32 / 8 - 1)) == 0)
hash = ((hash^l) * 0x9e370001UL);
} while (len);
return (hash >> (32 - bits)) & 0xffffffffUL;
}
static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
{
unsigned char buf, *p = eedata;
struct em28xx_eeprom *em_eeprom = (void *)eedata;
int i, err, size = len, block;
if (dev->chip_id == CHIP_ID_EM2874 || dev->chip_id == CHIP_ID_EM28174) {
/* Empia switched to a 16-bit addressable eeprom in newer
devices. While we could certainly write a routine to read
the eeprom, there is nothing of use in there that cannot be
accessed through registers, and there is the risk that we
could corrupt the eeprom (since a 16-bit read call is
interpreted as a write call by 8-bit eeproms).
*/
return 0;
}
dev->i2c_client.addr = 0xa0 >> 1;
/* Check if board has eeprom */
err = i2c_master_recv(&dev->i2c_client, &buf, 0);
if (err < 0) {
em28xx_errdev("board has no eeprom\n");
memset(eedata, 0, len);
return -ENODEV;
}
buf = 0;
err = i2c_master_send(&dev->i2c_client, &buf, 1);
if (err != 1) {
printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
dev->name, err);
return err;
}
while (size > 0) {
if (size > 16)
block = 16;
else
block = size;
if (block !=
(err = i2c_master_recv(&dev->i2c_client, p, block))) {
printk(KERN_WARNING
"%s: i2c eeprom read error (err=%d)\n",
dev->name, err);
return err;
}
size -= block;
p += block;
}
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");
}
if (em_eeprom->id == 0x9567eb1a)
dev->hash = em28xx_hash_mem(eedata, len, 32);
printk(KERN_INFO "%s: EEPROM ID= 0x%08x, EEPROM hash = 0x%08lx\n",
dev->name, em_eeprom->id, dev->hash);
printk(KERN_INFO "%s: EEPROM info:\n", dev->name);
switch (em_eeprom->chip_conf >> 4 & 0x3) {
case 0:
printk(KERN_INFO "%s:\tNo audio on board.\n", dev->name);
break;
case 1:
printk(KERN_INFO "%s:\tAC97 audio (5 sample rates)\n",
dev->name);
break;
case 2:
printk(KERN_INFO "%s:\tI2S audio, sample rate=32k\n",
dev->name);
break;
case 3:
printk(KERN_INFO "%s:\tI2S audio, 3 sample rates\n",
dev->name);
break;
}
if (em_eeprom->chip_conf & 1 << 3)
printk(KERN_INFO "%s:\tUSB Remote wakeup capable\n", dev->name);
if (em_eeprom->chip_conf & 1 << 2)
printk(KERN_INFO "%s:\tUSB Self power capable\n", dev->name);
switch (em_eeprom->chip_conf & 0x3) {
case 0:
printk(KERN_INFO "%s:\t500mA max power\n", dev->name);
break;
case 1:
printk(KERN_INFO "%s:\t400mA max power\n", dev->name);
break;
case 2:
printk(KERN_INFO "%s:\t300mA max power\n", dev->name);
break;
case 3:
printk(KERN_INFO "%s:\t200mA max power\n", dev->name);
break;
}
printk(KERN_INFO "%s:\tTable at 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
dev->name,
em_eeprom->string_idx_table,
em_eeprom->string1,
em_eeprom->string2,
em_eeprom->string3);
return 0;
}
/* ----------------------------------------------------------- */
/*
* functionality()
*/
static u32 functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL;
}
static struct i2c_algorithm em28xx_algo = {
.master_xfer = em28xx_i2c_xfer,
.functionality = functionality,
};
static struct i2c_adapter em28xx_adap_template = {
.owner = THIS_MODULE,
.name = "em28xx",
.algo = &em28xx_algo,
};
static struct i2c_client em28xx_client_template = {
.name = "em28xx internal",
};
/* ----------------------------------------------------------- */
/*
* i2c_devs
* incomplete list of known devices
*/
static char *i2c_devs[128] = {
[0x4a >> 1] = "saa7113h",
[0x60 >> 1] = "remote IR sensor",
[0x8e >> 1] = "remote IR sensor",
[0x86 >> 1] = "tda9887",
[0x80 >> 1] = "msp34xx",
[0x88 >> 1] = "msp34xx",
[0xa0 >> 1] = "eeprom",
[0xb0 >> 1] = "tda9874",
[0xb8 >> 1] = "tvp5150a",
[0xba >> 1] = "webcam sensor or tvp5150a",
[0xc0 >> 1] = "tuner (analog)",
[0xc2 >> 1] = "tuner (analog)",
[0xc4 >> 1] = "tuner (analog)",
[0xc6 >> 1] = "tuner (analog)",
};
/*
* do_i2c_scan()
* check i2c address range for devices
*/
void em28xx_do_i2c_scan(struct em28xx *dev)
{
u8 i2c_devicelist[128];
unsigned char buf;
int i, rc;
memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
dev->i2c_client.addr = i;
rc = i2c_master_recv(&dev->i2c_client, &buf, 0);
if (rc < 0)
continue;
i2c_devicelist[i] = i;
printk(KERN_INFO "%s: found i2c device @ 0x%x [%s]\n",
dev->name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
}
dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
ARRAY_SIZE(i2c_devicelist), 32);
}
/*
* em28xx_i2c_register()
* register i2c bus
*/
int em28xx_i2c_register(struct em28xx *dev)
{
int retval;
BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
dev->i2c_adap = em28xx_adap_template;
dev->i2c_adap.dev.parent = &dev->udev->dev;
strcpy(dev->i2c_adap.name, dev->name);
dev->i2c_adap.algo_data = dev;
i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
retval = i2c_add_adapter(&dev->i2c_adap);
if (retval < 0) {
em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
__func__, retval);
return retval;
}
dev->i2c_client = em28xx_client_template;
dev->i2c_client.adapter = &dev->i2c_adap;
retval = em28xx_i2c_eeprom(dev, dev->eedata, sizeof(dev->eedata));
if ((retval < 0) && (retval != -ENODEV)) {
em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
__func__, retval);
return retval;
}
if (i2c_scan)
em28xx_do_i2c_scan(dev);
/* Instantiate the IR receiver device, if present */
em28xx_register_i2c_ir(dev);
return 0;
}
/*
* em28xx_i2c_unregister()
* unregister i2c_bus
*/
int em28xx_i2c_unregister(struct em28xx *dev)
{
i2c_del_adapter(&dev->i2c_adap);
return 0;
}