drivers/media/i2c/lm3646.c - arm/linux - Git at Google

 /*
  * drivers/media/i2c/lm3646.c
  * General device driver for TI lm3646, Dual FLASH LED Driver
  *
  * Copyright (C) 2014 Texas Instruments
  *
  * Contact: Daniel Jeong <gshark.jeong@gmail.com>
  *			Ldd-Mlp <ldd-mlp@list.ti.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  */

 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/regmap.h>
 #include <linux/videodev2.h>
 #include <media/lm3646.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>

 /* registers definitions */
 #define REG_ENABLE		0x01
 #define REG_TORCH_BR	0x05
 #define REG_FLASH_BR	0x05
 #define REG_FLASH_TOUT	0x04
 #define REG_FLAG		0x08
 #define REG_STROBE_SRC	0x06
 #define REG_LED1_FLASH_BR 0x06
 #define REG_LED1_TORCH_BR 0x07

 #define MASK_ENABLE		0x03
 #define MASK_TORCH_BR	0x70
 #define MASK_FLASH_BR	0x0F
 #define MASK_FLASH_TOUT	0x07
 #define MASK_FLAG		0xFF
 #define MASK_STROBE_SRC	0x80

 /* Fault Mask */
 #define FAULT_TIMEOUT	(1<<0)
 #define FAULT_SHORT_CIRCUIT	(1<<1)
 #define FAULT_UVLO		(1<<2)
 #define FAULT_IVFM		(1<<3)
 #define FAULT_OCP		(1<<4)
 #define FAULT_OVERTEMP	(1<<5)
 #define FAULT_NTC_TRIP	(1<<6)
 #define FAULT_OVP		(1<<7)

 enum led_mode {
 	MODE_SHDN = 0x0,
 	MODE_TORCH = 0x2,
 	MODE_FLASH = 0x3,
 };

 /*
  * struct lm3646_flash
  *
  * @pdata: platform data
  * @regmap: reg. map for i2c
  * @lock: muxtex for serial access.
  * @led_mode: V4L2 LED mode
  * @ctrls_led: V4L2 contols
  * @subdev_led: V4L2 subdev
  * @mode_reg : mode register value
  */
 struct lm3646_flash {
 	struct device *dev;
 	struct lm3646_platform_data *pdata;
 	struct regmap *regmap;

 	struct v4l2_ctrl_handler ctrls_led;
 	struct v4l2_subdev subdev_led;

 	u8 mode_reg;
 };

 #define to_lm3646_flash(_ctrl)	\
 	container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)

 /* enable mode control */
 static int lm3646_mode_ctrl(struct lm3646_flash *flash,
 			    enum v4l2_flash_led_mode led_mode)
 {
 	switch (led_mode) {
 	case V4L2_FLASH_LED_MODE_NONE:
 		return regmap_write(flash->regmap,
 				    REG_ENABLE, flash->mode_reg | MODE_SHDN);
 	case V4L2_FLASH_LED_MODE_TORCH:
 		return regmap_write(flash->regmap,
 				    REG_ENABLE, flash->mode_reg | MODE_TORCH);
 	case V4L2_FLASH_LED_MODE_FLASH:
 		return regmap_write(flash->regmap,
 				    REG_ENABLE, flash->mode_reg | MODE_FLASH);
 	}
 	return -EINVAL;
 }

 /* V4L2 controls  */
 static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
 	unsigned int reg_val;
 	int rval;

 	if (ctrl->id != V4L2_CID_FLASH_FAULT)
 		return -EINVAL;

 	rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
 	if (rval < 0)
 		return rval;

 	ctrl->val = 0;
 	if (reg_val & FAULT_TIMEOUT)
 		ctrl->val |= V4L2_FLASH_FAULT_TIMEOUT;
 	if (reg_val & FAULT_SHORT_CIRCUIT)
 		ctrl->val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
 	if (reg_val & FAULT_UVLO)
 		ctrl->val |= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
 	if (reg_val & FAULT_IVFM)
 		ctrl->val |= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
 	if (reg_val & FAULT_OCP)
 		ctrl->val |= V4L2_FLASH_FAULT_OVER_CURRENT;
 	if (reg_val & FAULT_OVERTEMP)
 		ctrl->val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
 	if (reg_val & FAULT_NTC_TRIP)
 		ctrl->val |= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
 	if (reg_val & FAULT_OVP)
 		ctrl->val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;

 	return 0;
 }

 static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
 	unsigned int reg_val;
 	int rval = -EINVAL;

 	switch (ctrl->id) {
 	case V4L2_CID_FLASH_LED_MODE:

 		if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
 			return lm3646_mode_ctrl(flash, ctrl->val);
 		/* switch to SHDN mode before flash strobe on */
 		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);

 	case V4L2_CID_FLASH_STROBE_SOURCE:
 		return regmap_update_bits(flash->regmap,
 					  REG_STROBE_SRC, MASK_STROBE_SRC,
 					  (ctrl->val) << 7);

 	case V4L2_CID_FLASH_STROBE:

 		/* read and check current mode of chip to start flash */
 		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 		if (rval < 0 || ((reg_val & MASK_ENABLE) != MODE_SHDN))
 			return rval;
 		/* flash on */
 		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);

 	case V4L2_CID_FLASH_STROBE_STOP:

 		/*
 		 * flash mode will be turned automatically
 		 * from FLASH mode to SHDN mode after flash duration timeout
 		 * read and check current mode of chip to stop flash
 		 */
 		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 		if (rval < 0)
 			return rval;
 		if ((reg_val & MASK_ENABLE) == MODE_FLASH)
 			return lm3646_mode_ctrl(flash,
 						V4L2_FLASH_LED_MODE_NONE);
 		return rval;

 	case V4L2_CID_FLASH_TIMEOUT:
 		return regmap_update_bits(flash->regmap,
 					  REG_FLASH_TOUT, MASK_FLASH_TOUT,
 					  LM3646_FLASH_TOUT_ms_TO_REG
 					  (ctrl->val));

 	case V4L2_CID_FLASH_INTENSITY:
 		return regmap_update_bits(flash->regmap,
 					  REG_FLASH_BR, MASK_FLASH_BR,
 					  LM3646_TOTAL_FLASH_BRT_uA_TO_REG
 					  (ctrl->val));

 	case V4L2_CID_FLASH_TORCH_INTENSITY:
 		return regmap_update_bits(flash->regmap,
 					  REG_TORCH_BR, MASK_TORCH_BR,
 					  LM3646_TOTAL_TORCH_BRT_uA_TO_REG
 					  (ctrl->val) << 4);
 	}

 	return -EINVAL;
 }

 static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
 	.g_volatile_ctrl = lm3646_get_ctrl,
 	.s_ctrl = lm3646_set_ctrl,
 };

 static int lm3646_init_controls(struct lm3646_flash *flash)
 {
 	struct v4l2_ctrl *fault;
 	struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
 	const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;

 	v4l2_ctrl_handler_init(hdl, 8);
 	/* flash mode */
 	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
 			       V4L2_FLASH_LED_MODE_TORCH, ~0x7,
 			       V4L2_FLASH_LED_MODE_NONE);

 	/* flash source */
 	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
 			       0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);

 	/* flash strobe */
 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
 	/* flash strobe stop */
 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);

 	/* flash strobe timeout */
 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
 			  LM3646_FLASH_TOUT_MIN,
 			  LM3646_FLASH_TOUT_MAX,
 			  LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);

 	/* max flash current */
 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
 			  LM3646_TOTAL_FLASH_BRT_MIN,
 			  LM3646_TOTAL_FLASH_BRT_MAX,
 			  LM3646_TOTAL_FLASH_BRT_STEP,
 			  LM3646_TOTAL_FLASH_BRT_MAX);

 	/* max torch current */
 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
 			  LM3646_TOTAL_TORCH_BRT_MIN,
 			  LM3646_TOTAL_TORCH_BRT_MAX,
 			  LM3646_TOTAL_TORCH_BRT_STEP,
 			  LM3646_TOTAL_TORCH_BRT_MAX);

 	/* fault */
 	fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
 				  V4L2_FLASH_FAULT_OVER_VOLTAGE
 				  | V4L2_FLASH_FAULT_OVER_TEMPERATURE
 				  | V4L2_FLASH_FAULT_SHORT_CIRCUIT
 				  | V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
 	if (fault != NULL)
 		fault->flags |= V4L2_CTRL_FLAG_VOLATILE;

 	if (hdl->error)
 		return hdl->error;

 	flash->subdev_led.ctrl_handler = hdl;
 	return 0;
 }

 /* initialize device */
 static const struct v4l2_subdev_ops lm3646_ops = {
 	.core = NULL,
 };

 static const struct regmap_config lm3646_regmap = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = 0xFF,
 };

 static int lm3646_subdev_init(struct lm3646_flash *flash)
 {
 	struct i2c_client *client = to_i2c_client(flash->dev);
 	int rval;

 	v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
 	flash->subdev_led.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	strcpy(flash->subdev_led.name, LM3646_NAME);
 	rval = lm3646_init_controls(flash);
 	if (rval)
 		goto err_out;
 	rval = media_entity_init(&flash->subdev_led.entity, 0, NULL, 0);
 	if (rval < 0)
 		goto err_out;
 	flash->subdev_led.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
 	return rval;

 err_out:
 	v4l2_ctrl_handler_free(&flash->ctrls_led);
 	return rval;
 }

 static int lm3646_init_device(struct lm3646_flash *flash)
 {
 	unsigned int reg_val;
 	int rval;

 	/* read the value of mode register to reduce redundant i2c accesses */
 	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
 	if (rval < 0)
 		return rval;
 	flash->mode_reg = reg_val & 0xfc;

 	/* output disable */
 	rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
 	if (rval < 0)
 		return rval;

 	/*
 	 * LED1 flash current setting
 	 * LED2 flash current = Total(Max) flash current - LED1 flash current
 	 */
 	rval = regmap_update_bits(flash->regmap,
 				  REG_LED1_FLASH_BR, 0x7F,
 				  LM3646_LED1_FLASH_BRT_uA_TO_REG
 				  (flash->pdata->led1_flash_brt));

 	if (rval < 0)
 		return rval;

 	/*
 	 * LED1 torch current setting
 	 * LED2 torch current = Total(Max) torch current - LED1 torch current
 	 */
 	rval = regmap_update_bits(flash->regmap,
 				  REG_LED1_TORCH_BR, 0x7F,
 				  LM3646_LED1_TORCH_BRT_uA_TO_REG
 				  (flash->pdata->led1_torch_brt));
 	if (rval < 0)
 		return rval;

 	/* Reset flag register */
 	return regmap_read(flash->regmap, REG_FLAG, &reg_val);
 }

 static int lm3646_probe(struct i2c_client *client,
 			const struct i2c_device_id *devid)
 {
 	struct lm3646_flash *flash;
 	struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
 	int rval;

 	flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
 	if (flash == NULL)
 		return -ENOMEM;

 	flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
 	if (IS_ERR(flash->regmap))
 		return PTR_ERR(flash->regmap);

 	/* check device tree if there is no platform data */
 	if (pdata == NULL) {
 		pdata = devm_kzalloc(&client->dev,
 				     sizeof(struct lm3646_platform_data),
 				     GFP_KERNEL);
 		if (pdata == NULL)
 			return -ENOMEM;
 		/* use default data in case of no platform data */
 		pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
 		pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
 		pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
 	}
 	flash->pdata = pdata;
 	flash->dev = &client->dev;

 	rval = lm3646_subdev_init(flash);
 	if (rval < 0)
 		return rval;

 	rval = lm3646_init_device(flash);
 	if (rval < 0)
 		return rval;

 	i2c_set_clientdata(client, flash);

 	return 0;
 }

 static int lm3646_remove(struct i2c_client *client)
 {
 	struct lm3646_flash *flash = i2c_get_clientdata(client);

 	v4l2_device_unregister_subdev(&flash->subdev_led);
 	v4l2_ctrl_handler_free(&flash->ctrls_led);
 	media_entity_cleanup(&flash->subdev_led.entity);

 	return 0;
 }

 static const struct i2c_device_id lm3646_id_table[] = {
 	{LM3646_NAME, 0},
 	{}
 };

 MODULE_DEVICE_TABLE(i2c, lm3646_id_table);

 static struct i2c_driver lm3646_i2c_driver = {
 	.driver = {
 		   .name = LM3646_NAME,
 		   },
 	.probe = lm3646_probe,
 	.remove = lm3646_remove,
 	.id_table = lm3646_id_table,
 };

 module_i2c_driver(lm3646_i2c_driver);

 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
 MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
 MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
 MODULE_LICENSE("GPL");
	/*
	* drivers/media/i2c/lm3646.c
	* General device driver for TI lm3646, Dual FLASH LED Driver
	*
	* Copyright (C) 2014 Texas Instruments
	*
	* Contact: Daniel Jeong <gshark.jeong@gmail.com>
	* Ldd-Mlp <ldd-mlp@list.ti.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* version 2 as published by the Free Software Foundation.
	*/

	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/regmap.h>
	#include <linux/videodev2.h>
	#include <media/lm3646.h>
	#include <media/v4l2-ctrls.h>
	#include <media/v4l2-device.h>

	/* registers definitions */
	#define REG_ENABLE 0x01
	#define REG_TORCH_BR 0x05
	#define REG_FLASH_BR 0x05
	#define REG_FLASH_TOUT 0x04
	#define REG_FLAG 0x08
	#define REG_STROBE_SRC 0x06
	#define REG_LED1_FLASH_BR 0x06
	#define REG_LED1_TORCH_BR 0x07

	#define MASK_ENABLE 0x03
	#define MASK_TORCH_BR 0x70
	#define MASK_FLASH_BR 0x0F
	#define MASK_FLASH_TOUT 0x07
	#define MASK_FLAG 0xFF
	#define MASK_STROBE_SRC 0x80

	/* Fault Mask */
	#define FAULT_TIMEOUT (1<<0)
	#define FAULT_SHORT_CIRCUIT (1<<1)
	#define FAULT_UVLO (1<<2)
	#define FAULT_IVFM (1<<3)
	#define FAULT_OCP (1<<4)
	#define FAULT_OVERTEMP (1<<5)
	#define FAULT_NTC_TRIP (1<<6)
	#define FAULT_OVP (1<<7)

	enum led_mode {
	MODE_SHDN = 0x0,
	MODE_TORCH = 0x2,
	MODE_FLASH = 0x3,
	};

	/*
	* struct lm3646_flash
	*
	* @pdata: platform data
	* @regmap: reg. map for i2c
	* @lock: muxtex for serial access.
	* @led_mode: V4L2 LED mode
	* @ctrls_led: V4L2 contols
	* @subdev_led: V4L2 subdev
	* @mode_reg : mode register value
	*/
	struct lm3646_flash {
	struct device *dev;
	struct lm3646_platform_data *pdata;
	struct regmap *regmap;

	struct v4l2_ctrl_handler ctrls_led;
	struct v4l2_subdev subdev_led;

	u8 mode_reg;
	};

	#define to_lm3646_flash(_ctrl) \
	container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)

	/* enable mode control */
	static int lm3646_mode_ctrl(struct lm3646_flash *flash,
	enum v4l2_flash_led_mode led_mode)
	{
	switch (led_mode) {
	case V4L2_FLASH_LED_MODE_NONE:
	return regmap_write(flash->regmap,
	REG_ENABLE, flash->mode_reg \| MODE_SHDN);
	case V4L2_FLASH_LED_MODE_TORCH:
	return regmap_write(flash->regmap,
	REG_ENABLE, flash->mode_reg \| MODE_TORCH);
	case V4L2_FLASH_LED_MODE_FLASH:
	return regmap_write(flash->regmap,
	REG_ENABLE, flash->mode_reg \| MODE_FLASH);
	}
	return -EINVAL;
	}

	/* V4L2 controls */
	static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
	unsigned int reg_val;
	int rval;

	if (ctrl->id != V4L2_CID_FLASH_FAULT)
	return -EINVAL;

	rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
	if (rval < 0)
	return rval;

	ctrl->val = 0;
	if (reg_val & FAULT_TIMEOUT)
	ctrl->val \|= V4L2_FLASH_FAULT_TIMEOUT;
	if (reg_val & FAULT_SHORT_CIRCUIT)
	ctrl->val \|= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
	if (reg_val & FAULT_UVLO)
	ctrl->val \|= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
	if (reg_val & FAULT_IVFM)
	ctrl->val \|= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
	if (reg_val & FAULT_OCP)
	ctrl->val \|= V4L2_FLASH_FAULT_OVER_CURRENT;
	if (reg_val & FAULT_OVERTEMP)
	ctrl->val \|= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
	if (reg_val & FAULT_NTC_TRIP)
	ctrl->val \|= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
	if (reg_val & FAULT_OVP)
	ctrl->val \|= V4L2_FLASH_FAULT_OVER_VOLTAGE;

	return 0;
	}

	static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
	unsigned int reg_val;
	int rval = -EINVAL;

	switch (ctrl->id) {
	case V4L2_CID_FLASH_LED_MODE:

	if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
	return lm3646_mode_ctrl(flash, ctrl->val);
	/* switch to SHDN mode before flash strobe on */
	return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);

	case V4L2_CID_FLASH_STROBE_SOURCE:
	return regmap_update_bits(flash->regmap,
	REG_STROBE_SRC, MASK_STROBE_SRC,
	(ctrl->val) << 7);

	case V4L2_CID_FLASH_STROBE:

	/* read and check current mode of chip to start flash */
	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
	if (rval < 0 \|\| ((reg_val & MASK_ENABLE) != MODE_SHDN))
	return rval;
	/* flash on */
	return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);

	case V4L2_CID_FLASH_STROBE_STOP:

	/*
	* flash mode will be turned automatically
	* from FLASH mode to SHDN mode after flash duration timeout
	* read and check current mode of chip to stop flash
	*/
	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
	if (rval < 0)
	return rval;
	if ((reg_val & MASK_ENABLE) == MODE_FLASH)
	return lm3646_mode_ctrl(flash,
	V4L2_FLASH_LED_MODE_NONE);
	return rval;

	case V4L2_CID_FLASH_TIMEOUT:
	return regmap_update_bits(flash->regmap,
	REG_FLASH_TOUT, MASK_FLASH_TOUT,
	LM3646_FLASH_TOUT_ms_TO_REG
	(ctrl->val));

	case V4L2_CID_FLASH_INTENSITY:
	return regmap_update_bits(flash->regmap,
	REG_FLASH_BR, MASK_FLASH_BR,
	LM3646_TOTAL_FLASH_BRT_uA_TO_REG
	(ctrl->val));

	case V4L2_CID_FLASH_TORCH_INTENSITY:
	return regmap_update_bits(flash->regmap,
	REG_TORCH_BR, MASK_TORCH_BR,
	LM3646_TOTAL_TORCH_BRT_uA_TO_REG
	(ctrl->val) << 4);
	}

	return -EINVAL;
	}

	static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
	.g_volatile_ctrl = lm3646_get_ctrl,
	.s_ctrl = lm3646_set_ctrl,
	};

	static int lm3646_init_controls(struct lm3646_flash *flash)
	{
	struct v4l2_ctrl *fault;
	struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
	const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;

	v4l2_ctrl_handler_init(hdl, 8);
	/* flash mode */
	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
	V4L2_FLASH_LED_MODE_TORCH, ~0x7,
	V4L2_FLASH_LED_MODE_NONE);

	/* flash source */
	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
	0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);

	/* flash strobe */
	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
	/* flash strobe stop */
	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);

	/* flash strobe timeout */
	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
	LM3646_FLASH_TOUT_MIN,
	LM3646_FLASH_TOUT_MAX,
	LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);

	/* max flash current */
	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
	LM3646_TOTAL_FLASH_BRT_MIN,
	LM3646_TOTAL_FLASH_BRT_MAX,
	LM3646_TOTAL_FLASH_BRT_STEP,
	LM3646_TOTAL_FLASH_BRT_MAX);

	/* max torch current */
	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
	LM3646_TOTAL_TORCH_BRT_MIN,
	LM3646_TOTAL_TORCH_BRT_MAX,
	LM3646_TOTAL_TORCH_BRT_STEP,
	LM3646_TOTAL_TORCH_BRT_MAX);

	/* fault */
	fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
	V4L2_FLASH_FAULT_OVER_VOLTAGE
	\| V4L2_FLASH_FAULT_OVER_TEMPERATURE
	\| V4L2_FLASH_FAULT_SHORT_CIRCUIT
	\| V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
	if (fault != NULL)
	fault->flags \|= V4L2_CTRL_FLAG_VOLATILE;

	if (hdl->error)
	return hdl->error;

	flash->subdev_led.ctrl_handler = hdl;
	return 0;
	}

	/* initialize device */
	static const struct v4l2_subdev_ops lm3646_ops = {
	.core = NULL,
	};

	static const struct regmap_config lm3646_regmap = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0xFF,
	};

	static int lm3646_subdev_init(struct lm3646_flash *flash)
	{
	struct i2c_client *client = to_i2c_client(flash->dev);
	int rval;

	v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
	flash->subdev_led.flags \|= V4L2_SUBDEV_FL_HAS_DEVNODE;
	strcpy(flash->subdev_led.name, LM3646_NAME);
	rval = lm3646_init_controls(flash);
	if (rval)
	goto err_out;
	rval = media_entity_init(&flash->subdev_led.entity, 0, NULL, 0);
	if (rval < 0)
	goto err_out;
	flash->subdev_led.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
	return rval;

	err_out:
	v4l2_ctrl_handler_free(&flash->ctrls_led);
	return rval;
	}

	static int lm3646_init_device(struct lm3646_flash *flash)
	{
	unsigned int reg_val;
	int rval;

	/* read the value of mode register to reduce redundant i2c accesses */
	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
	if (rval < 0)
	return rval;
	flash->mode_reg = reg_val & 0xfc;

	/* output disable */
	rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
	if (rval < 0)
	return rval;

	/*
	* LED1 flash current setting
	* LED2 flash current = Total(Max) flash current - LED1 flash current
	*/
	rval = regmap_update_bits(flash->regmap,
	REG_LED1_FLASH_BR, 0x7F,
	LM3646_LED1_FLASH_BRT_uA_TO_REG
	(flash->pdata->led1_flash_brt));

	if (rval < 0)
	return rval;

	/*
	* LED1 torch current setting
	* LED2 torch current = Total(Max) torch current - LED1 torch current
	*/
	rval = regmap_update_bits(flash->regmap,
	REG_LED1_TORCH_BR, 0x7F,
	LM3646_LED1_TORCH_BRT_uA_TO_REG
	(flash->pdata->led1_torch_brt));
	if (rval < 0)
	return rval;

	/* Reset flag register */
	return regmap_read(flash->regmap, REG_FLAG, &reg_val);
	}

	static int lm3646_probe(struct i2c_client *client,
	const struct i2c_device_id *devid)
	{
	struct lm3646_flash *flash;
	struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
	int rval;

	flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
	if (flash == NULL)
	return -ENOMEM;

	flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
	if (IS_ERR(flash->regmap))
	return PTR_ERR(flash->regmap);

	/* check device tree if there is no platform data */
	if (pdata == NULL) {
	pdata = devm_kzalloc(&client->dev,
	sizeof(struct lm3646_platform_data),
	GFP_KERNEL);
	if (pdata == NULL)
	return -ENOMEM;
	/* use default data in case of no platform data */
	pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
	pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
	pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
	}
	flash->pdata = pdata;
	flash->dev = &client->dev;

	rval = lm3646_subdev_init(flash);
	if (rval < 0)
	return rval;

	rval = lm3646_init_device(flash);
	if (rval < 0)
	return rval;

	i2c_set_clientdata(client, flash);

	return 0;
	}

	static int lm3646_remove(struct i2c_client *client)
	{
	struct lm3646_flash *flash = i2c_get_clientdata(client);

	v4l2_device_unregister_subdev(&flash->subdev_led);
	v4l2_ctrl_handler_free(&flash->ctrls_led);
	media_entity_cleanup(&flash->subdev_led.entity);

	return 0;
	}

	static const struct i2c_device_id lm3646_id_table[] = {
	{LM3646_NAME, 0},
	{}
	};

	MODULE_DEVICE_TABLE(i2c, lm3646_id_table);

	static struct i2c_driver lm3646_i2c_driver = {
	.driver = {
	.name = LM3646_NAME,
	},
	.probe = lm3646_probe,
	.remove = lm3646_remove,
	.id_table = lm3646_id_table,
	};

	module_i2c_driver(lm3646_i2c_driver);

	MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
	MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
	MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
	MODULE_LICENSE("GPL");