drivers/media/platform/s5p-tv/sii9234_drv.c - linux - Git at Google

 /*
  * Samsung MHL interface driver
  *
  * Copyright (C) 2011 Samsung Electronics Co.Ltd
  * Author: Tomasz Stanislawski <t.stanislaws@samsung.com>
  *
  * 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.
  */

 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/freezer.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/machine.h>
 #include <linux/slab.h>

 #include <media/sii9234.h>
 #include <media/v4l2-subdev.h>

 MODULE_AUTHOR("Tomasz Stanislawski <t.stanislaws@samsung.com>");
 MODULE_DESCRIPTION("Samsung MHL interface driver");
 MODULE_LICENSE("GPL");

 struct sii9234_context {
 	struct i2c_client *client;
 	struct regulator *power;
 	int gpio_n_reset;
 	struct v4l2_subdev sd;
 };

 static inline struct sii9234_context *sd_to_context(struct v4l2_subdev *sd)
 {
 	return container_of(sd, struct sii9234_context, sd);
 }

 static inline int sii9234_readb(struct i2c_client *client, int addr)
 {
 	return i2c_smbus_read_byte_data(client, addr);
 }

 static inline int sii9234_writeb(struct i2c_client *client, int addr, int value)
 {
 	return i2c_smbus_write_byte_data(client, addr, value);
 }

 static inline int sii9234_writeb_mask(struct i2c_client *client, int addr,
 	int value, int mask)
 {
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, addr);
 	if (ret < 0)
 		return ret;
 	ret = (ret & ~mask) | (value & mask);
 	return i2c_smbus_write_byte_data(client, addr, ret);
 }

 static inline int sii9234_readb_idx(struct i2c_client *client, int addr)
 {
 	int ret;
 	ret = i2c_smbus_write_byte_data(client, 0xbc, addr >> 8);
 	if (ret < 0)
 		return ret;
 	ret = i2c_smbus_write_byte_data(client, 0xbd, addr & 0xff);
 	if (ret < 0)
 		return ret;
 	return i2c_smbus_read_byte_data(client, 0xbe);
 }

 static inline int sii9234_writeb_idx(struct i2c_client *client, int addr,
 	int value)
 {
 	int ret;
 	ret = i2c_smbus_write_byte_data(client, 0xbc, addr >> 8);
 	if (ret < 0)
 		return ret;
 	ret = i2c_smbus_write_byte_data(client, 0xbd, addr & 0xff);
 	if (ret < 0)
 		return ret;
 	ret = i2c_smbus_write_byte_data(client, 0xbe, value);
 	return ret;
 }

 static inline int sii9234_writeb_idx_mask(struct i2c_client *client, int addr,
 	int value, int mask)
 {
 	int ret;

 	ret = sii9234_readb_idx(client, addr);
 	if (ret < 0)
 		return ret;
 	ret = (ret & ~mask) | (value & mask);
 	return sii9234_writeb_idx(client, addr, ret);
 }

 static int sii9234_reset(struct sii9234_context *ctx)
 {
 	struct i2c_client *client = ctx->client;
 	struct device *dev = &client->dev;
 	int ret, tries;

 	gpio_direction_output(ctx->gpio_n_reset, 1);
 	mdelay(1);
 	gpio_direction_output(ctx->gpio_n_reset, 0);
 	mdelay(1);
 	gpio_direction_output(ctx->gpio_n_reset, 1);
 	mdelay(1);

 	/* going to TTPI mode */
 	ret = sii9234_writeb(client, 0xc7, 0);
 	if (ret < 0) {
 		dev_err(dev, "failed to set TTPI mode\n");
 		return ret;
 	}
 	for (tries = 0; tries < 100 ; ++tries) {
 		ret = sii9234_readb(client, 0x1b);
 		if (ret > 0)
 			break;
 		if (ret < 0) {
 			dev_err(dev, "failed to reset device\n");
 			return -EIO;
 		}
 		mdelay(1);
 	}
 	if (tries == 100) {
 		dev_err(dev, "maximal number of tries reached\n");
 		return -EIO;
 	}

 	return 0;
 }

 static int sii9234_verify_version(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	int family, rev, tpi_rev, dev_id, sub_id, hdcp, id;

 	family = sii9234_readb(client, 0x1b);
 	rev = sii9234_readb(client, 0x1c) & 0x0f;
 	tpi_rev = sii9234_readb(client, 0x1d) & 0x7f;
 	dev_id = sii9234_readb_idx(client, 0x0103);
 	sub_id = sii9234_readb_idx(client, 0x0102);
 	hdcp = sii9234_readb(client, 0x30);

 	if (family < 0 || rev < 0 || tpi_rev < 0 || dev_id < 0 ||
 		sub_id < 0 || hdcp < 0) {
 		dev_err(dev, "failed to read chip's version\n");
 		return -EIO;
 	}

 	id = (dev_id << 8) | sub_id;

 	dev_info(dev, "chip: SiL%02x family: %02x, rev: %02x\n",
 		id, family, rev);
 	dev_info(dev, "tpi_rev:%02x, hdcp: %02x\n", tpi_rev, hdcp);
 	if (id != 0x9234) {
 		dev_err(dev, "not supported chip\n");
 		return -ENODEV;
 	}

 	return 0;
 }

 static u8 data[][3] = {
 /* setup from driver created by doonsoo45.kim */
 	{ 0x01, 0x05, 0x04 }, /* Enable Auto soft reset on SCDT = 0 */
 	{ 0x01, 0x08, 0x35 }, /* Power Up TMDS Tx Core */
 	{ 0x01, 0x0d, 0x1c }, /* HDMI Transcode mode enable */
 	{ 0x01, 0x2b, 0x01 }, /* Enable HDCP Compliance workaround */
 	{ 0x01, 0x79, 0x40 }, /* daniel test...MHL_INT */
 	{ 0x01, 0x80, 0x34 }, /* Enable Rx PLL Clock Value */
 	{ 0x01, 0x90, 0x27 }, /* Enable CBUS discovery */
 	{ 0x01, 0x91, 0xe5 }, /* Skip RGND detection */
 	{ 0x01, 0x92, 0x46 }, /* Force MHD mode */
 	{ 0x01, 0x93, 0xdc }, /* Disable CBUS pull-up during RGND measurement */
 	{ 0x01, 0x94, 0x66 }, /* 1.8V CBUS VTH & GND threshold */
 	{ 0x01, 0x95, 0x31 }, /* RGND block & single discovery attempt */
 	{ 0x01, 0x96, 0x22 }, /* use 1K and 2K setting */
 	{ 0x01, 0xa0, 0x10 }, /* SIMG: Term mode */
 	{ 0x01, 0xa1, 0xfc }, /* Disable internal Mobile HD driver */
 	{ 0x01, 0xa3, 0xfa }, /* SIMG: Output Swing  default EB, 3x Clk Mult */
 	{ 0x01, 0xa5, 0x80 }, /* SIMG: RGND Hysterisis, 3x mode for Beast */
 	{ 0x01, 0xa6, 0x0c }, /* SIMG: Swing Offset */
 	{ 0x02, 0x3d, 0x3f }, /* Power up CVCC 1.2V core */
 	{ 0x03, 0x00, 0x00 }, /* SIMG: correcting HW default */
 	{ 0x03, 0x11, 0x01 }, /* Enable TxPLL Clock */
 	{ 0x03, 0x12, 0x15 }, /* Enable Tx Clock Path & Equalizer */
 	{ 0x03, 0x13, 0x60 }, /* SIMG: Set termination value */
 	{ 0x03, 0x14, 0xf0 }, /* SIMG: Change CKDT level */
 	{ 0x03, 0x17, 0x07 }, /* SIMG: PLL Calrefsel */
 	{ 0x03, 0x1a, 0x20 }, /* VCO Cal */
 	{ 0x03, 0x22, 0xe0 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x23, 0xc0 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x24, 0xa0 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x25, 0x80 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x26, 0x60 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x27, 0x40 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x28, 0x20 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x29, 0x00 }, /* SIMG: Auto EQ */
 	{ 0x03, 0x31, 0x0b }, /* SIMG: Rx PLL BW value from I2C BW ~ 4MHz */
 	{ 0x03, 0x45, 0x06 }, /* SIMG: DPLL Mode */
 	{ 0x03, 0x4b, 0x06 }, /* SIMG: Correcting HW default */
 	{ 0x03, 0x4c, 0xa0 }, /* Manual zone control */
 	{ 0x03, 0x4d, 0x02 }, /* SIMG: PLL Mode Value (order is important) */
 };

 static int sii9234_set_internal(struct sii9234_context *ctx)
 {
 	struct i2c_client *client = ctx->client;
 	int i, ret;

 	for (i = 0; i < ARRAY_SIZE(data); ++i) {
 		int addr = (data[i][0] << 8) | data[i][1];
 		ret = sii9234_writeb_idx(client, addr, data[i][2]);
 		if (ret < 0)
 			return ret;
 	}
 	return 0;
 }

 static int sii9234_runtime_suspend(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct sii9234_context *ctx = sd_to_context(sd);
 	struct i2c_client *client = ctx->client;

 	dev_info(dev, "suspend start\n");

 	sii9234_writeb_mask(client, 0x1e, 3, 3);
 	regulator_disable(ctx->power);

 	return 0;
 }

 static int sii9234_runtime_resume(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct sii9234_context *ctx = sd_to_context(sd);
 	struct i2c_client *client = ctx->client;
 	int ret;

 	dev_info(dev, "resume start\n");
 	regulator_enable(ctx->power);

 	ret = sii9234_reset(ctx);
 	if (ret)
 		goto fail;

 	/* enable tpi */
 	ret = sii9234_writeb_mask(client, 0x1e, 1, 0);
 	if (ret < 0)
 		goto fail;
 	ret = sii9234_set_internal(ctx);
 	if (ret < 0)
 		goto fail;

 	return 0;

 fail:
 	dev_err(dev, "failed to resume\n");
 	regulator_disable(ctx->power);

 	return ret;
 }

 static const struct dev_pm_ops sii9234_pm_ops = {
 	.runtime_suspend = sii9234_runtime_suspend,
 	.runtime_resume	 = sii9234_runtime_resume,
 };

 static int sii9234_s_power(struct v4l2_subdev *sd, int on)
 {
 	struct sii9234_context *ctx = sd_to_context(sd);
 	int ret;

 	if (on)
 		ret = pm_runtime_get_sync(&ctx->client->dev);
 	else
 		ret = pm_runtime_put(&ctx->client->dev);
 	/* only values < 0 indicate errors */
 	return IS_ERR_VALUE(ret) ? ret : 0;
 }

 static int sii9234_s_stream(struct v4l2_subdev *sd, int enable)
 {
 	struct sii9234_context *ctx = sd_to_context(sd);

 	/* (dis/en)able TDMS output */
 	sii9234_writeb_mask(ctx->client, 0x1a, enable ? 0 : ~0 , 1 << 4);
 	return 0;
 }

 static const struct v4l2_subdev_core_ops sii9234_core_ops = {
 	.s_power =  sii9234_s_power,
 };

 static const struct v4l2_subdev_video_ops sii9234_video_ops = {
 	.s_stream =  sii9234_s_stream,
 };

 static const struct v4l2_subdev_ops sii9234_ops = {
 	.core = &sii9234_core_ops,
 	.video = &sii9234_video_ops,
 };

 static int sii9234_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	struct sii9234_platform_data *pdata = dev->platform_data;
 	struct sii9234_context *ctx;
 	int ret;

 	ctx = devm_kzalloc(&client->dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx) {
 		dev_err(dev, "out of memory\n");
 		ret = -ENOMEM;
 		goto fail;
 	}
 	ctx->client = client;

 	ctx->power = devm_regulator_get(dev, "hdmi-en");
 	if (IS_ERR(ctx->power)) {
 		dev_err(dev, "failed to acquire regulator hdmi-en\n");
 		return PTR_ERR(ctx->power);
 	}

 	ctx->gpio_n_reset = pdata->gpio_n_reset;
 	ret = devm_gpio_request(dev, ctx->gpio_n_reset, "MHL_RST");
 	if (ret) {
 		dev_err(dev, "failed to acquire MHL_RST gpio\n");
 		return ret;
 	}

 	v4l2_i2c_subdev_init(&ctx->sd, client, &sii9234_ops);

 	pm_runtime_enable(dev);

 	/* enable device */
 	ret = pm_runtime_get_sync(dev);
 	if (ret)
 		goto fail_pm;

 	/* verify chip version */
 	ret = sii9234_verify_version(client);
 	if (ret)
 		goto fail_pm_get;

 	/* stop processing */
 	pm_runtime_put(dev);

 	dev_info(dev, "probe successful\n");

 	return 0;

 fail_pm_get:
 	pm_runtime_put_sync(dev);

 fail_pm:
 	pm_runtime_disable(dev);

 fail:
 	dev_err(dev, "probe failed\n");

 	return ret;
 }

 static int sii9234_remove(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;

 	pm_runtime_disable(dev);

 	dev_info(dev, "remove successful\n");

 	return 0;
 }


 static const struct i2c_device_id sii9234_id[] = {
 	{ "SII9234", 0 },
 	{ },
 };

 MODULE_DEVICE_TABLE(i2c, sii9234_id);
 static struct i2c_driver sii9234_driver = {
 	.driver = {
 		.name	= "sii9234",
 		.owner	= THIS_MODULE,
 		.pm = &sii9234_pm_ops,
 	},
 	.probe		= sii9234_probe,
 	.remove		= sii9234_remove,
 	.id_table = sii9234_id,
 };

 module_i2c_driver(sii9234_driver);
	/*
	* Samsung MHL interface driver
	*
	* Copyright (C) 2011 Samsung Electronics Co.Ltd
	* Author: Tomasz Stanislawski <t.stanislaws@samsung.com>
	*
	* 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.
	*/

	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/freezer.h>
	#include <linux/gpio.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/kthread.h>
	#include <linux/module.h>
	#include <linux/pm_runtime.h>
	#include <linux/regulator/machine.h>
	#include <linux/slab.h>

	#include <media/sii9234.h>
	#include <media/v4l2-subdev.h>

	MODULE_AUTHOR("Tomasz Stanislawski <t.stanislaws@samsung.com>");
	MODULE_DESCRIPTION("Samsung MHL interface driver");
	MODULE_LICENSE("GPL");

	struct sii9234_context {
	struct i2c_client *client;
	struct regulator *power;
	int gpio_n_reset;
	struct v4l2_subdev sd;
	};

	static inline struct sii9234_context sd_to_context(struct v4l2_subdev sd)
	{
	return container_of(sd, struct sii9234_context, sd);
	}

	static inline int sii9234_readb(struct i2c_client *client, int addr)
	{
	return i2c_smbus_read_byte_data(client, addr);
	}

	static inline int sii9234_writeb(struct i2c_client *client, int addr, int value)
	{
	return i2c_smbus_write_byte_data(client, addr, value);
	}

	static inline int sii9234_writeb_mask(struct i2c_client *client, int addr,
	int value, int mask)
	{
	int ret;

	ret = i2c_smbus_read_byte_data(client, addr);
	if (ret < 0)
	return ret;
	ret = (ret & ~mask) \| (value & mask);
	return i2c_smbus_write_byte_data(client, addr, ret);
	}

	static inline int sii9234_readb_idx(struct i2c_client *client, int addr)
	{
	int ret;
	ret = i2c_smbus_write_byte_data(client, 0xbc, addr >> 8);
	if (ret < 0)
	return ret;
	ret = i2c_smbus_write_byte_data(client, 0xbd, addr & 0xff);
	if (ret < 0)
	return ret;
	return i2c_smbus_read_byte_data(client, 0xbe);
	}

	static inline int sii9234_writeb_idx(struct i2c_client *client, int addr,
	int value)
	{
	int ret;
	ret = i2c_smbus_write_byte_data(client, 0xbc, addr >> 8);
	if (ret < 0)
	return ret;
	ret = i2c_smbus_write_byte_data(client, 0xbd, addr & 0xff);
	if (ret < 0)
	return ret;
	ret = i2c_smbus_write_byte_data(client, 0xbe, value);
	return ret;
	}

	static inline int sii9234_writeb_idx_mask(struct i2c_client *client, int addr,
	int value, int mask)
	{
	int ret;

	ret = sii9234_readb_idx(client, addr);
	if (ret < 0)
	return ret;
	ret = (ret & ~mask) \| (value & mask);
	return sii9234_writeb_idx(client, addr, ret);
	}

	static int sii9234_reset(struct sii9234_context *ctx)
	{
	struct i2c_client *client = ctx->client;
	struct device *dev = &client->dev;
	int ret, tries;

	gpio_direction_output(ctx->gpio_n_reset, 1);
	mdelay(1);
	gpio_direction_output(ctx->gpio_n_reset, 0);
	mdelay(1);
	gpio_direction_output(ctx->gpio_n_reset, 1);
	mdelay(1);

	/* going to TTPI mode */
	ret = sii9234_writeb(client, 0xc7, 0);
	if (ret < 0) {
	dev_err(dev, "failed to set TTPI mode\n");
	return ret;
	}
	for (tries = 0; tries < 100 ; ++tries) {
	ret = sii9234_readb(client, 0x1b);
	if (ret > 0)
	break;
	if (ret < 0) {
	dev_err(dev, "failed to reset device\n");
	return -EIO;
	}
	mdelay(1);
	}
	if (tries == 100) {
	dev_err(dev, "maximal number of tries reached\n");
	return -EIO;
	}

	return 0;
	}

	static int sii9234_verify_version(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	int family, rev, tpi_rev, dev_id, sub_id, hdcp, id;

	family = sii9234_readb(client, 0x1b);
	rev = sii9234_readb(client, 0x1c) & 0x0f;
	tpi_rev = sii9234_readb(client, 0x1d) & 0x7f;
	dev_id = sii9234_readb_idx(client, 0x0103);
	sub_id = sii9234_readb_idx(client, 0x0102);
	hdcp = sii9234_readb(client, 0x30);

	if (family < 0 \|\| rev < 0 \|\| tpi_rev < 0 \|\| dev_id < 0 \|\|
	sub_id < 0 \|\| hdcp < 0) {
	dev_err(dev, "failed to read chip's version\n");
	return -EIO;
	}

	id = (dev_id << 8) \| sub_id;

	dev_info(dev, "chip: SiL%02x family: %02x, rev: %02x\n",
	id, family, rev);
	dev_info(dev, "tpi_rev:%02x, hdcp: %02x\n", tpi_rev, hdcp);
	if (id != 0x9234) {
	dev_err(dev, "not supported chip\n");
	return -ENODEV;
	}

	return 0;
	}

	static u8 data[][3] = {
	/* setup from driver created by doonsoo45.kim */
	{ 0x01, 0x05, 0x04 }, /* Enable Auto soft reset on SCDT = 0 */
	{ 0x01, 0x08, 0x35 }, /* Power Up TMDS Tx Core */
	{ 0x01, 0x0d, 0x1c }, /* HDMI Transcode mode enable */
	{ 0x01, 0x2b, 0x01 }, /* Enable HDCP Compliance workaround */
	{ 0x01, 0x79, 0x40 }, /* daniel test...MHL_INT */
	{ 0x01, 0x80, 0x34 }, /* Enable Rx PLL Clock Value */
	{ 0x01, 0x90, 0x27 }, /* Enable CBUS discovery */
	{ 0x01, 0x91, 0xe5 }, /* Skip RGND detection */
	{ 0x01, 0x92, 0x46 }, /* Force MHD mode */
	{ 0x01, 0x93, 0xdc }, /* Disable CBUS pull-up during RGND measurement */
	{ 0x01, 0x94, 0x66 }, /* 1.8V CBUS VTH & GND threshold */
	{ 0x01, 0x95, 0x31 }, /* RGND block & single discovery attempt */
	{ 0x01, 0x96, 0x22 }, /* use 1K and 2K setting */
	{ 0x01, 0xa0, 0x10 }, /* SIMG: Term mode */
	{ 0x01, 0xa1, 0xfc }, /* Disable internal Mobile HD driver */
	{ 0x01, 0xa3, 0xfa }, /* SIMG: Output Swing default EB, 3x Clk Mult */
	{ 0x01, 0xa5, 0x80 }, /* SIMG: RGND Hysterisis, 3x mode for Beast */
	{ 0x01, 0xa6, 0x0c }, /* SIMG: Swing Offset */
	{ 0x02, 0x3d, 0x3f }, /* Power up CVCC 1.2V core */
	{ 0x03, 0x00, 0x00 }, /* SIMG: correcting HW default */
	{ 0x03, 0x11, 0x01 }, /* Enable TxPLL Clock */
	{ 0x03, 0x12, 0x15 }, /* Enable Tx Clock Path & Equalizer */
	{ 0x03, 0x13, 0x60 }, /* SIMG: Set termination value */
	{ 0x03, 0x14, 0xf0 }, /* SIMG: Change CKDT level */
	{ 0x03, 0x17, 0x07 }, /* SIMG: PLL Calrefsel */
	{ 0x03, 0x1a, 0x20 }, /* VCO Cal */
	{ 0x03, 0x22, 0xe0 }, /* SIMG: Auto EQ */
	{ 0x03, 0x23, 0xc0 }, /* SIMG: Auto EQ */
	{ 0x03, 0x24, 0xa0 }, /* SIMG: Auto EQ */
	{ 0x03, 0x25, 0x80 }, /* SIMG: Auto EQ */
	{ 0x03, 0x26, 0x60 }, /* SIMG: Auto EQ */
	{ 0x03, 0x27, 0x40 }, /* SIMG: Auto EQ */
	{ 0x03, 0x28, 0x20 }, /* SIMG: Auto EQ */
	{ 0x03, 0x29, 0x00 }, /* SIMG: Auto EQ */
	{ 0x03, 0x31, 0x0b }, /* SIMG: Rx PLL BW value from I2C BW ~ 4MHz */
	{ 0x03, 0x45, 0x06 }, /* SIMG: DPLL Mode */
	{ 0x03, 0x4b, 0x06 }, /* SIMG: Correcting HW default */
	{ 0x03, 0x4c, 0xa0 }, /* Manual zone control */
	{ 0x03, 0x4d, 0x02 }, /* SIMG: PLL Mode Value (order is important) */
	};

	static int sii9234_set_internal(struct sii9234_context *ctx)
	{
	struct i2c_client *client = ctx->client;
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(data); ++i) {
	int addr = (data[i][0] << 8) \| data[i][1];
	ret = sii9234_writeb_idx(client, addr, data[i][2]);
	if (ret < 0)
	return ret;
	}
	return 0;
	}

	static int sii9234_runtime_suspend(struct device *dev)
	{
	struct v4l2_subdev *sd = dev_get_drvdata(dev);
	struct sii9234_context *ctx = sd_to_context(sd);
	struct i2c_client *client = ctx->client;

	dev_info(dev, "suspend start\n");

	sii9234_writeb_mask(client, 0x1e, 3, 3);
	regulator_disable(ctx->power);

	return 0;
	}

	static int sii9234_runtime_resume(struct device *dev)
	{
	struct v4l2_subdev *sd = dev_get_drvdata(dev);
	struct sii9234_context *ctx = sd_to_context(sd);
	struct i2c_client *client = ctx->client;
	int ret;

	dev_info(dev, "resume start\n");
	regulator_enable(ctx->power);

	ret = sii9234_reset(ctx);
	if (ret)
	goto fail;

	/* enable tpi */
	ret = sii9234_writeb_mask(client, 0x1e, 1, 0);
	if (ret < 0)
	goto fail;
	ret = sii9234_set_internal(ctx);
	if (ret < 0)
	goto fail;

	return 0;

	fail:
	dev_err(dev, "failed to resume\n");
	regulator_disable(ctx->power);

	return ret;
	}

	static const struct dev_pm_ops sii9234_pm_ops = {
	.runtime_suspend = sii9234_runtime_suspend,
	.runtime_resume = sii9234_runtime_resume,
	};

	static int sii9234_s_power(struct v4l2_subdev *sd, int on)
	{
	struct sii9234_context *ctx = sd_to_context(sd);
	int ret;

	if (on)
	ret = pm_runtime_get_sync(&ctx->client->dev);
	else
	ret = pm_runtime_put(&ctx->client->dev);
	/* only values < 0 indicate errors */
	return IS_ERR_VALUE(ret) ? ret : 0;
	}

	static int sii9234_s_stream(struct v4l2_subdev *sd, int enable)
	{
	struct sii9234_context *ctx = sd_to_context(sd);

	/* (dis/en)able TDMS output */
	sii9234_writeb_mask(ctx->client, 0x1a, enable ? 0 : ~0 , 1 << 4);
	return 0;
	}

	static const struct v4l2_subdev_core_ops sii9234_core_ops = {
	.s_power = sii9234_s_power,
	};

	static const struct v4l2_subdev_video_ops sii9234_video_ops = {
	.s_stream = sii9234_s_stream,
	};

	static const struct v4l2_subdev_ops sii9234_ops = {
	.core = &sii9234_core_ops,
	.video = &sii9234_video_ops,
	};

	static int sii9234_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	struct sii9234_platform_data *pdata = dev->platform_data;
	struct sii9234_context *ctx;
	int ret;

	ctx = devm_kzalloc(&client->dev, sizeof(*ctx), GFP_KERNEL);
	if (!ctx) {
	dev_err(dev, "out of memory\n");
	ret = -ENOMEM;
	goto fail;
	}
	ctx->client = client;

	ctx->power = devm_regulator_get(dev, "hdmi-en");
	if (IS_ERR(ctx->power)) {
	dev_err(dev, "failed to acquire regulator hdmi-en\n");
	return PTR_ERR(ctx->power);
	}

	ctx->gpio_n_reset = pdata->gpio_n_reset;
	ret = devm_gpio_request(dev, ctx->gpio_n_reset, "MHL_RST");
	if (ret) {
	dev_err(dev, "failed to acquire MHL_RST gpio\n");
	return ret;
	}

	v4l2_i2c_subdev_init(&ctx->sd, client, &sii9234_ops);

	pm_runtime_enable(dev);

	/* enable device */
	ret = pm_runtime_get_sync(dev);
	if (ret)
	goto fail_pm;

	/* verify chip version */
	ret = sii9234_verify_version(client);
	if (ret)
	goto fail_pm_get;

	/* stop processing */
	pm_runtime_put(dev);

	dev_info(dev, "probe successful\n");

	return 0;

	fail_pm_get:
	pm_runtime_put_sync(dev);

	fail_pm:
	pm_runtime_disable(dev);

	fail:
	dev_err(dev, "probe failed\n");

	return ret;
	}

	static int sii9234_remove(struct i2c_client *client)
	{
	struct device *dev = &client->dev;

	pm_runtime_disable(dev);

	dev_info(dev, "remove successful\n");

	return 0;
	}


	static const struct i2c_device_id sii9234_id[] = {
	{ "SII9234", 0 },
	{ },
	};

	MODULE_DEVICE_TABLE(i2c, sii9234_id);
	static struct i2c_driver sii9234_driver = {
	.driver = {
	.name = "sii9234",
	.owner = THIS_MODULE,
	.pm = &sii9234_pm_ops,
	},
	.probe = sii9234_probe,
	.remove = sii9234_remove,
	.id_table = sii9234_id,
	};

	module_i2c_driver(sii9234_driver);