drivers/media/pci/cx23885/cx23885-i2c.c - linux-mtk - Git at Google

 /*
  *  Driver for the Conexant CX23885 PCIe bridge
  *
  *  Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
  *
  *  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.
  */

 #include "cx23885.h"

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <asm/io.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 dprintk(level, fmt, arg...)\
 	do { if (i2c_debug >= level)\
 		printk(KERN_DEBUG pr_fmt("%s: i2c:" fmt), \
 			__func__, ##arg); \
 	} while (0)

 #define I2C_WAIT_DELAY 32
 #define I2C_WAIT_RETRY 64

 #define I2C_EXTEND  (1 << 3)
 #define I2C_NOSTOP  (1 << 4)

 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
 {
 	struct cx23885_i2c *bus = i2c_adap->algo_data;
 	struct cx23885_dev *dev = bus->dev;
 	return cx_read(bus->reg_stat) & 0x01;
 }

 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 {
 	struct cx23885_i2c *bus = i2c_adap->algo_data;
 	struct cx23885_dev *dev = bus->dev;
 	return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
 }

 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 {
 	int count;

 	for (count = 0; count < I2C_WAIT_RETRY; count++) {
 		if (!i2c_is_busy(i2c_adap))
 			break;
 		udelay(I2C_WAIT_DELAY);
 	}

 	if (I2C_WAIT_RETRY == count)
 		return 0;

 	return 1;
 }

 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 			 const struct i2c_msg *msg, int joined_rlen)
 {
 	struct cx23885_i2c *bus = i2c_adap->algo_data;
 	struct cx23885_dev *dev = bus->dev;
 	u32 wdata, addr, ctrl;
 	int retval, cnt;

 	if (joined_rlen)
 		dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
 			msg->len, joined_rlen);
 	else
 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

 	/* Deal with i2c probe functions with zero payload */
 	if (msg->len == 0) {
 		cx_write(bus->reg_addr, msg->addr << 25);
 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
 		if (!i2c_wait_done(i2c_adap))
 			return -EIO;
 		if (!i2c_slave_did_ack(i2c_adap))
 			return -ENXIO;

 		dprintk(1, "%s() returns 0\n", __func__);
 		return 0;
 	}


 	/* dev, reg + first byte */
 	addr = (msg->addr << 25) | msg->buf[0];
 	wdata = msg->buf[0];
 	ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

 	if (msg->len > 1)
 		ctrl |= I2C_NOSTOP | I2C_EXTEND;
 	else if (joined_rlen)
 		ctrl |= I2C_NOSTOP;

 	cx_write(bus->reg_addr, addr);
 	cx_write(bus->reg_wdata, wdata);
 	cx_write(bus->reg_ctrl, ctrl);

 	if (!i2c_wait_done(i2c_adap))
 		goto eio;
 	if (i2c_debug) {
 		printk(KERN_DEBUG " <W %02x %02x", msg->addr << 1, msg->buf[0]);
 		if (!(ctrl & I2C_NOSTOP))
 			pr_cont(" >\n");
 	}

 	for (cnt = 1; cnt < msg->len; cnt++) {
 		/* following bytes */
 		wdata = msg->buf[cnt];
 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

 		if (cnt < msg->len - 1)
 			ctrl |= I2C_NOSTOP | I2C_EXTEND;
 		else if (joined_rlen)
 			ctrl |= I2C_NOSTOP;

 		cx_write(bus->reg_addr, addr);
 		cx_write(bus->reg_wdata, wdata);
 		cx_write(bus->reg_ctrl, ctrl);

 		if (!i2c_wait_done(i2c_adap))
 			goto eio;
 		if (i2c_debug) {
 			pr_cont(" %02x", msg->buf[cnt]);
 			if (!(ctrl & I2C_NOSTOP))
 				pr_cont(" >\n");
 		}
 	}
 	return msg->len;

  eio:
 	retval = -EIO;
 	if (i2c_debug)
 		pr_err(" ERR: %d\n", retval);
 	return retval;
 }

 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 			 const struct i2c_msg *msg, int joined)
 {
 	struct cx23885_i2c *bus = i2c_adap->algo_data;
 	struct cx23885_dev *dev = bus->dev;
 	u32 ctrl, cnt;
 	int retval;


 	if (i2c_debug && !joined)
 		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

 	/* Deal with i2c probe functions with zero payload */
 	if (msg->len == 0) {
 		cx_write(bus->reg_addr, msg->addr << 25);
 		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
 		if (!i2c_wait_done(i2c_adap))
 			return -EIO;
 		if (!i2c_slave_did_ack(i2c_adap))
 			return -ENXIO;


 		dprintk(1, "%s() returns 0\n", __func__);
 		return 0;
 	}

 	if (i2c_debug) {
 		if (joined)
 			dprintk(1, " R");
 		else
 			dprintk(1, " <R %02x", (msg->addr << 1) + 1);
 	}

 	for (cnt = 0; cnt < msg->len; cnt++) {

 		ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;

 		if (cnt < msg->len - 1)
 			ctrl |= I2C_NOSTOP | I2C_EXTEND;

 		cx_write(bus->reg_addr, msg->addr << 25);
 		cx_write(bus->reg_ctrl, ctrl);

 		if (!i2c_wait_done(i2c_adap))
 			goto eio;
 		msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 		if (i2c_debug) {
 			dprintk(1, " %02x", msg->buf[cnt]);
 			if (!(ctrl & I2C_NOSTOP))
 				dprintk(1, " >\n");
 		}
 	}
 	return msg->len;

  eio:
 	retval = -EIO;
 	if (i2c_debug)
 		pr_err(" ERR: %d\n", retval);
 	return retval;
 }

 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 		    struct i2c_msg *msgs, int num)
 {
 	int i, retval = 0;

 	dprintk(1, "%s(num = %d)\n", __func__, num);

 	for (i = 0 ; i < num; i++) {
 		dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 			__func__, num, msgs[i].addr, msgs[i].len);
 		if (msgs[i].flags & I2C_M_RD) {
 			/* read */
 			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 			   msgs[i].addr == msgs[i + 1].addr) {
 			/* write then read from same address */
 			retval = i2c_sendbytes(i2c_adap, &msgs[i],
 					       msgs[i + 1].len);
 			if (retval < 0)
 				goto err;
 			i++;
 			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 		} else {
 			/* write */
 			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 		}
 		if (retval < 0)
 			goto err;
 	}
 	return num;

  err:
 	return retval;
 }

 static u32 cx23885_functionality(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 }

 static const struct i2c_algorithm cx23885_i2c_algo_template = {
 	.master_xfer	= i2c_xfer,
 	.functionality	= cx23885_functionality,
 };

 /* ----------------------------------------------------------------------- */

 static const struct i2c_adapter cx23885_i2c_adap_template = {
 	.name              = "cx23885",
 	.owner             = THIS_MODULE,
 	.algo              = &cx23885_i2c_algo_template,
 };

 static const struct i2c_client cx23885_i2c_client_template = {
 	.name	= "cx23885 internal",
 };

 static char *i2c_devs[128] = {
 	[0x10 >> 1] = "tda10048",
 	[0x12 >> 1] = "dib7000pc",
 	[0x1c >> 1] = "lgdt3303",
 	[0x80 >> 1] = "cs3308",
 	[0x82 >> 1] = "cs3308",
 	[0x86 >> 1] = "tda9887",
 	[0x32 >> 1] = "cx24227",
 	[0x88 >> 1] = "cx25837",
 	[0x84 >> 1] = "tda8295",
 	[0x98 >> 1] = "flatiron",
 	[0xa0 >> 1] = "eeprom",
 	[0xc0 >> 1] = "tuner/mt2131/tda8275",
 	[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
 	[0xc8 >> 1] = "tuner/xc3028L",
 };

 static void do_i2c_scan(char *name, struct i2c_client *c)
 {
 	unsigned char buf;
 	int i, rc;

 	for (i = 0; i < 128; i++) {
 		c->addr = i;
 		rc = i2c_master_recv(c, &buf, 0);
 		if (rc < 0)
 			continue;
 		pr_info("%s: i2c scan: found device @ 0x%04x  [%s]\n",
 		       name, i, i2c_devs[i] ? i2c_devs[i] : "???");
 	}
 }

 /* init + register i2c adapter */
 int cx23885_i2c_register(struct cx23885_i2c *bus)
 {
 	struct cx23885_dev *dev = bus->dev;

 	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);

 	bus->i2c_adap = cx23885_i2c_adap_template;
 	bus->i2c_client = cx23885_i2c_client_template;
 	bus->i2c_adap.dev.parent = &dev->pci->dev;

 	strlcpy(bus->i2c_adap.name, bus->dev->name,
 		sizeof(bus->i2c_adap.name));

 	bus->i2c_adap.algo_data = bus;
 	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
 	i2c_add_adapter(&bus->i2c_adap);

 	bus->i2c_client.adapter = &bus->i2c_adap;

 	if (0 == bus->i2c_rc) {
 		dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
 		if (i2c_scan) {
 			pr_info("%s: scan bus %d:\n",
 					dev->name, bus->nr);
 			do_i2c_scan(dev->name, &bus->i2c_client);
 		}
 	} else
 		pr_warn("%s: i2c bus %d register FAILED\n",
 			dev->name, bus->nr);

 	/* Instantiate the IR receiver device, if present */
 	if (0 == bus->i2c_rc) {
 		struct i2c_board_info info;
 		const unsigned short addr_list[] = {
 			0x6b, I2C_CLIENT_END
 		};

 		memset(&info, 0, sizeof(struct i2c_board_info));
 		strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
 		/* Use quick read command for probe, some IR chips don't
 		 * support writes */
 		i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
 				      i2c_probe_func_quick_read);
 	}

 	return bus->i2c_rc;
 }

 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
 {
 	i2c_del_adapter(&bus->i2c_adap);
 	return 0;
 }

 void cx23885_av_clk(struct cx23885_dev *dev, int enable)
 {
 	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
 	char buffer[3];
 	struct i2c_msg msg;
 	dprintk(1, "%s(enabled = %d)\n", __func__, enable);

 	/* Register 0x144 */
 	buffer[0] = 0x01;
 	buffer[1] = 0x44;
 	if (enable == 1)
 		buffer[2] = 0x05;
 	else
 		buffer[2] = 0x00;

 	msg.addr = 0x44;
 	msg.flags = I2C_M_TEN;
 	msg.len = 3;
 	msg.buf = buffer;

 	i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
 }
	/*
	* Driver for the Conexant CX23885 PCIe bridge
	*
	* Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
	*
	* 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.
	*/

	#include "cx23885.h"

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/init.h>
	#include <linux/delay.h>
	#include <asm/io.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 dprintk(level, fmt, arg...)\
	do { if (i2c_debug >= level)\
	printk(KERN_DEBUG pr_fmt("%s: i2c:" fmt), \
	__func__, ##arg); \
	} while (0)

	#define I2C_WAIT_DELAY 32
	#define I2C_WAIT_RETRY 64

	#define I2C_EXTEND (1 << 3)
	#define I2C_NOSTOP (1 << 4)

	static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
	{
	struct cx23885_i2c *bus = i2c_adap->algo_data;
	struct cx23885_dev *dev = bus->dev;
	return cx_read(bus->reg_stat) & 0x01;
	}

	static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
	{
	struct cx23885_i2c *bus = i2c_adap->algo_data;
	struct cx23885_dev *dev = bus->dev;
	return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
	}

	static int i2c_wait_done(struct i2c_adapter *i2c_adap)
	{
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
	if (!i2c_is_busy(i2c_adap))
	break;
	udelay(I2C_WAIT_DELAY);
	}

	if (I2C_WAIT_RETRY == count)
	return 0;

	return 1;
	}

	static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
	const struct i2c_msg *msg, int joined_rlen)
	{
	struct cx23885_i2c *bus = i2c_adap->algo_data;
	struct cx23885_dev *dev = bus->dev;
	u32 wdata, addr, ctrl;
	int retval, cnt;

	if (joined_rlen)
	dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
	msg->len, joined_rlen);
	else
	dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

	/* Deal with i2c probe functions with zero payload */
	if (msg->len == 0) {
	cx_write(bus->reg_addr, msg->addr << 25);
	cx_write(bus->reg_ctrl, bus->i2c_period \| (1 << 2));
	if (!i2c_wait_done(i2c_adap))
	return -EIO;
	if (!i2c_slave_did_ack(i2c_adap))
	return -ENXIO;

	dprintk(1, "%s() returns 0\n", __func__);
	return 0;
	}


	/* dev, reg + first byte */
	addr = (msg->addr << 25) \| msg->buf[0];
	wdata = msg->buf[0];
	ctrl = bus->i2c_period \| (1 << 12) \| (1 << 2);

	if (msg->len > 1)
	ctrl \|= I2C_NOSTOP \| I2C_EXTEND;
	else if (joined_rlen)
	ctrl \|= I2C_NOSTOP;

	cx_write(bus->reg_addr, addr);
	cx_write(bus->reg_wdata, wdata);
	cx_write(bus->reg_ctrl, ctrl);

	if (!i2c_wait_done(i2c_adap))
	goto eio;
	if (i2c_debug) {
	printk(KERN_DEBUG " <W %02x %02x", msg->addr << 1, msg->buf[0]);
	if (!(ctrl & I2C_NOSTOP))
	pr_cont(" >\n");
	}

	for (cnt = 1; cnt < msg->len; cnt++) {
	/* following bytes */
	wdata = msg->buf[cnt];
	ctrl = bus->i2c_period \| (1 << 12) \| (1 << 2);

	if (cnt < msg->len - 1)
	ctrl \|= I2C_NOSTOP \| I2C_EXTEND;
	else if (joined_rlen)
	ctrl \|= I2C_NOSTOP;

	cx_write(bus->reg_addr, addr);
	cx_write(bus->reg_wdata, wdata);
	cx_write(bus->reg_ctrl, ctrl);

	if (!i2c_wait_done(i2c_adap))
	goto eio;
	if (i2c_debug) {
	pr_cont(" %02x", msg->buf[cnt]);
	if (!(ctrl & I2C_NOSTOP))
	pr_cont(" >\n");
	}
	}
	return msg->len;

	eio:
	retval = -EIO;
	if (i2c_debug)
	pr_err(" ERR: %d\n", retval);
	return retval;
	}

	static int i2c_readbytes(struct i2c_adapter *i2c_adap,
	const struct i2c_msg *msg, int joined)
	{
	struct cx23885_i2c *bus = i2c_adap->algo_data;
	struct cx23885_dev *dev = bus->dev;
	u32 ctrl, cnt;
	int retval;


	if (i2c_debug && !joined)
	dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

	/* Deal with i2c probe functions with zero payload */
	if (msg->len == 0) {
	cx_write(bus->reg_addr, msg->addr << 25);
	cx_write(bus->reg_ctrl, bus->i2c_period \| (1 << 2) \| 1);
	if (!i2c_wait_done(i2c_adap))
	return -EIO;
	if (!i2c_slave_did_ack(i2c_adap))
	return -ENXIO;


	dprintk(1, "%s() returns 0\n", __func__);
	return 0;
	}

	if (i2c_debug) {
	if (joined)
	dprintk(1, " R");
	else
	dprintk(1, " <R %02x", (msg->addr << 1) + 1);
	}

	for (cnt = 0; cnt < msg->len; cnt++) {

	ctrl = bus->i2c_period \| (1 << 12) \| (1 << 2) \| 1;

	if (cnt < msg->len - 1)
	ctrl \|= I2C_NOSTOP \| I2C_EXTEND;

	cx_write(bus->reg_addr, msg->addr << 25);
	cx_write(bus->reg_ctrl, ctrl);

	if (!i2c_wait_done(i2c_adap))
	goto eio;
	msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
	if (i2c_debug) {
	dprintk(1, " %02x", msg->buf[cnt]);
	if (!(ctrl & I2C_NOSTOP))
	dprintk(1, " >\n");
	}
	}
	return msg->len;

	eio:
	retval = -EIO;
	if (i2c_debug)
	pr_err(" ERR: %d\n", retval);
	return retval;
	}

	static int i2c_xfer(struct i2c_adapter *i2c_adap,
	struct i2c_msg *msgs, int num)
	{
	int i, retval = 0;

	dprintk(1, "%s(num = %d)\n", __func__, num);

	for (i = 0 ; i < num; i++) {
	dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n",
	__func__, num, msgs[i].addr, msgs[i].len);
	if (msgs[i].flags & I2C_M_RD) {
	/* read */
	retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
	} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
	msgs[i].addr == msgs[i + 1].addr) {
	/* write then read from same address */
	retval = i2c_sendbytes(i2c_adap, &msgs[i],
	msgs[i + 1].len);
	if (retval < 0)
	goto err;
	i++;
	retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
	} else {
	/* write */
	retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
	}
	if (retval < 0)
	goto err;
	}
	return num;

	err:
	return retval;
	}

	static u32 cx23885_functionality(struct i2c_adapter *adap)
	{
	return I2C_FUNC_SMBUS_EMUL \| I2C_FUNC_I2C;
	}

	static const struct i2c_algorithm cx23885_i2c_algo_template = {
	.master_xfer = i2c_xfer,
	.functionality = cx23885_functionality,
	};

	/* ----------------------------------------------------------------------- */

	static const struct i2c_adapter cx23885_i2c_adap_template = {
	.name = "cx23885",
	.owner = THIS_MODULE,
	.algo = &cx23885_i2c_algo_template,
	};

	static const struct i2c_client cx23885_i2c_client_template = {
	.name = "cx23885 internal",
	};

	static char *i2c_devs[128] = {
	[0x10 >> 1] = "tda10048",
	[0x12 >> 1] = "dib7000pc",
	[0x1c >> 1] = "lgdt3303",
	[0x80 >> 1] = "cs3308",
	[0x82 >> 1] = "cs3308",
	[0x86 >> 1] = "tda9887",
	[0x32 >> 1] = "cx24227",
	[0x88 >> 1] = "cx25837",
	[0x84 >> 1] = "tda8295",
	[0x98 >> 1] = "flatiron",
	[0xa0 >> 1] = "eeprom",
	[0xc0 >> 1] = "tuner/mt2131/tda8275",
	[0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
	[0xc8 >> 1] = "tuner/xc3028L",
	};

	static void do_i2c_scan(char name, struct i2c_client c)
	{
	unsigned char buf;
	int i, rc;

	for (i = 0; i < 128; i++) {
	c->addr = i;
	rc = i2c_master_recv(c, &buf, 0);
	if (rc < 0)
	continue;
	pr_info("%s: i2c scan: found device @ 0x%04x [%s]\n",
	name, i, i2c_devs[i] ? i2c_devs[i] : "???");
	}
	}

	/* init + register i2c adapter */
	int cx23885_i2c_register(struct cx23885_i2c *bus)
	{
	struct cx23885_dev *dev = bus->dev;

	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);

	bus->i2c_adap = cx23885_i2c_adap_template;
	bus->i2c_client = cx23885_i2c_client_template;
	bus->i2c_adap.dev.parent = &dev->pci->dev;

	strlcpy(bus->i2c_adap.name, bus->dev->name,
	sizeof(bus->i2c_adap.name));

	bus->i2c_adap.algo_data = bus;
	i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
	i2c_add_adapter(&bus->i2c_adap);

	bus->i2c_client.adapter = &bus->i2c_adap;

	if (0 == bus->i2c_rc) {
	dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
	if (i2c_scan) {
	pr_info("%s: scan bus %d:\n",
	dev->name, bus->nr);
	do_i2c_scan(dev->name, &bus->i2c_client);
	}
	} else
	pr_warn("%s: i2c bus %d register FAILED\n",
	dev->name, bus->nr);

	/* Instantiate the IR receiver device, if present */
	if (0 == bus->i2c_rc) {
	struct i2c_board_info info;
	const unsigned short addr_list[] = {
	0x6b, I2C_CLIENT_END
	};

	memset(&info, 0, sizeof(struct i2c_board_info));
	strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
	/* Use quick read command for probe, some IR chips don't
	* support writes */
	i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
	i2c_probe_func_quick_read);
	}

	return bus->i2c_rc;
	}

	int cx23885_i2c_unregister(struct cx23885_i2c *bus)
	{
	i2c_del_adapter(&bus->i2c_adap);
	return 0;
	}

	void cx23885_av_clk(struct cx23885_dev *dev, int enable)
	{
	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
	char buffer[3];
	struct i2c_msg msg;
	dprintk(1, "%s(enabled = %d)\n", __func__, enable);

	/* Register 0x144 */
	buffer[0] = 0x01;
	buffer[1] = 0x44;
	if (enable == 1)
	buffer[2] = 0x05;
	else
	buffer[2] = 0x00;

	msg.addr = 0x44;
	msg.flags = I2C_M_TEN;
	msg.len = 3;
	msg.buf = buffer;

	i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
	}