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linux/drivers/media/video/bt8xx/bttv-i2c.c
Jean Delvare a824f0f445 [media] video: Drop undue references to i2c-algo-bit 
There's one comment that has been copied from bttv to many other
media/video drivers:

/* init + register i2c algo-bit adapter */

Meanwhile, many drivers use hardware I2C implementations instead of
relying on i2c-algo-bit, so this comment is misleading. Remove the
reference to "algo-bit" from all drivers, to avoid any confusion. This
is the best way to ensure that the comments won't go out of sync
again. Anyone interested in the implementation details would rather
look at the code itself.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-11-24 15:11:17 -02:00

398 lines
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/*
bttv-i2c.c -- all the i2c code is here
bttv - Bt848 frame grabber driver
Copyright (C) 1996,97,98 Ralph Metzler (rjkm@thp.uni-koeln.de)
& Marcus Metzler (mocm@thp.uni-koeln.de)
(c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
(c) 2005 Mauro Carvalho Chehab <mchehab@infradead.org>
- Multituner support and i2c address binding
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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include "bttvp.h"
#include <media/v4l2-common.h>
#include <linux/jiffies.h>
#include <asm/io.h>
static int i2c_debug;
static int i2c_hw;
static int i2c_scan;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
module_param(i2c_hw, int, 0444);
MODULE_PARM_DESC(i2c_hw,"force use of hardware i2c support, "
"instead of software bitbang");
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
static unsigned int i2c_udelay = 5;
module_param(i2c_udelay, int, 0444);
MODULE_PARM_DESC(i2c_udelay,"soft i2c delay at insmod time, in usecs "
"(should be 5 or higher). Lower value means higher bus speed.");
/* ----------------------------------------------------------------------- */
/* I2C functions - bitbanging adapter (software i2c) */
static void bttv_bit_setscl(void *data, int state)
{
struct bttv *btv = (struct bttv*)data;
if (state)
btv->i2c_state |= 0x02;
else
btv->i2c_state &= ~0x02;
btwrite(btv->i2c_state, BT848_I2C);
btread(BT848_I2C);
}
static void bttv_bit_setsda(void *data, int state)
{
struct bttv *btv = (struct bttv*)data;
if (state)
btv->i2c_state |= 0x01;
else
btv->i2c_state &= ~0x01;
btwrite(btv->i2c_state, BT848_I2C);
btread(BT848_I2C);
}
static int bttv_bit_getscl(void *data)
{
struct bttv *btv = (struct bttv*)data;
int state;
state = btread(BT848_I2C) & 0x02 ? 1 : 0;
return state;
}
static int bttv_bit_getsda(void *data)
{
struct bttv *btv = (struct bttv*)data;
int state;
state = btread(BT848_I2C) & 0x01;
return state;
}
static struct i2c_algo_bit_data __devinitdata bttv_i2c_algo_bit_template = {
.setsda = bttv_bit_setsda,
.setscl = bttv_bit_setscl,
.getsda = bttv_bit_getsda,
.getscl = bttv_bit_getscl,
.udelay = 16,
.timeout = 200,
};
/* ----------------------------------------------------------------------- */
/* I2C functions - hardware i2c */
static u32 functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_SMBUS_EMUL;
}
static int
bttv_i2c_wait_done(struct bttv *btv)
{
int rc = 0;
/* timeout */
if (wait_event_interruptible_timeout(btv->i2c_queue,
btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
rc = -EIO;
if (btv->i2c_done & BT848_INT_RACK)
rc = 1;
btv->i2c_done = 0;
return rc;
}
#define I2C_HW (BT878_I2C_MODE | BT848_I2C_SYNC |\
BT848_I2C_SCL | BT848_I2C_SDA)
static int
bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
{
u32 xmit;
int retval,cnt;
/* sanity checks */
if (0 == msg->len)
return -EINVAL;
/* start, address + first byte */
xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
if (msg->len > 1 || !last)
xmit |= BT878_I2C_NOSTOP;
btwrite(xmit, BT848_I2C);
retval = bttv_i2c_wait_done(btv);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
if (i2c_debug) {
pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
}
for (cnt = 1; cnt < msg->len; cnt++ ) {
/* following bytes */
xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
if (cnt < msg->len-1 || !last)
xmit |= BT878_I2C_NOSTOP;
btwrite(xmit, BT848_I2C);
retval = bttv_i2c_wait_done(btv);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
if (i2c_debug)
pr_cont(" %02x", msg->buf[cnt]);
}
if (!(xmit & BT878_I2C_NOSTOP))
pr_cont(">\n");
return msg->len;
eio:
retval = -EIO;
err:
if (i2c_debug)
pr_cont(" ERR: %d\n",retval);
return retval;
}
static int
bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
{
u32 xmit;
u32 cnt;
int retval;
for (cnt = 0; cnt < msg->len; cnt++) {
xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
if (cnt < msg->len-1)
xmit |= BT848_I2C_W3B;
if (cnt < msg->len-1 || !last)
xmit |= BT878_I2C_NOSTOP;
if (cnt)
xmit |= BT878_I2C_NOSTART;
if (i2c_debug) {
if (!(xmit & BT878_I2C_NOSTART))
pr_cont(" <R %02x", (msg->addr << 1) +1);
}
btwrite(xmit, BT848_I2C);
retval = bttv_i2c_wait_done(btv);
if (retval < 0)
goto err;
if (retval == 0)
goto eio;
msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
if (i2c_debug) {
pr_cont(" =%02x", msg->buf[cnt]);
}
if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
pr_cont(" >\n");
}
return msg->len;
eio:
retval = -EIO;
err:
if (i2c_debug)
pr_cont(" ERR: %d\n",retval);
return retval;
}
static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
struct bttv *btv = to_bttv(v4l2_dev);
int retval = 0;
int i;
if (i2c_debug)
pr_debug("bt-i2c:");
btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
for (i = 0 ; i < num; i++) {
if (msgs[i].flags & I2C_M_RD) {
/* read */
retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
if (retval < 0)
goto err;
} else {
/* write */
retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
if (retval < 0)
goto err;
}
}
return num;
err:
return retval;
}
static const struct i2c_algorithm bttv_algo = {
.master_xfer = bttv_i2c_xfer,
.functionality = functionality,
};
/* ----------------------------------------------------------------------- */
/* I2C functions - common stuff */
/* read I2C */
int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
{
unsigned char buffer = 0;
if (0 != btv->i2c_rc)
return -1;
if (bttv_verbose && NULL != probe_for)
pr_info("%d: i2c: checking for %s @ 0x%02x... ",
btv->c.nr, probe_for, addr);
btv->i2c_client.addr = addr >> 1;
if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
if (NULL != probe_for) {
if (bttv_verbose)
pr_cont("not found\n");
} else
pr_warn("%d: i2c read 0x%x: error\n",
btv->c.nr, addr);
return -1;
}
if (bttv_verbose && NULL != probe_for)
pr_cont("found\n");
return buffer;
}
/* write I2C */
int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
unsigned char b2, int both)
{
unsigned char buffer[2];
int bytes = both ? 2 : 1;
if (0 != btv->i2c_rc)
return -1;
btv->i2c_client.addr = addr >> 1;
buffer[0] = b1;
buffer[1] = b2;
if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
return -1;
return 0;
}
/* read EEPROM content */
void __devinit bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
{
memset(eedata, 0, 256);
if (0 != btv->i2c_rc)
return;
btv->i2c_client.addr = addr >> 1;
tveeprom_read(&btv->i2c_client, eedata, 256);
}
static char *i2c_devs[128] = {
[ 0x1c >> 1 ] = "lgdt330x",
[ 0x30 >> 1 ] = "IR (hauppauge)",
[ 0x80 >> 1 ] = "msp34xx",
[ 0x86 >> 1 ] = "tda9887",
[ 0xa0 >> 1 ] = "eeprom",
[ 0xc0 >> 1 ] = "tuner (analog)",
[ 0xc2 >> 1 ] = "tuner (analog)",
};
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;
pr_info("%s: i2c scan: found device @ 0x%x [%s]\n",
name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
}
}
/* init + register i2c adapter */
int __devinit init_bttv_i2c(struct bttv *btv)
{
strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
if (i2c_hw)
btv->use_i2c_hw = 1;
if (btv->use_i2c_hw) {
/* bt878 */
strlcpy(btv->c.i2c_adap.name, "bt878",
sizeof(btv->c.i2c_adap.name));
btv->c.i2c_adap.algo = &bttv_algo;
} else {
/* bt848 */
/* Prevents usage of invalid delay values */
if (i2c_udelay<5)
i2c_udelay=5;
strlcpy(btv->c.i2c_adap.name, "bttv",
sizeof(btv->c.i2c_adap.name));
memcpy(&btv->i2c_algo, &bttv_i2c_algo_bit_template,
sizeof(bttv_i2c_algo_bit_template));
btv->i2c_algo.udelay = i2c_udelay;
btv->i2c_algo.data = btv;
btv->c.i2c_adap.algo_data = &btv->i2c_algo;
}
btv->c.i2c_adap.owner = THIS_MODULE;
btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
"bt%d #%d [%s]", btv->id, btv->c.nr,
btv->use_i2c_hw ? "hw" : "sw");
i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
btv->i2c_client.adapter = &btv->c.i2c_adap;
if (btv->use_i2c_hw) {
btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
} else {
bttv_bit_setscl(btv,1);
bttv_bit_setsda(btv,1);
btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
}
if (0 == btv->i2c_rc && i2c_scan)
do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
return btv->i2c_rc;
}
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