drivers/leds/leds-lm3530.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2011 ST-Ericsson SA.
  * Copyright (C) 2009 Motorola, Inc.
  *
  * License Terms: GNU General Public License v2
  *
  * Simple driver for National Semiconductor LM3530 Backlight driver chip
  *
  * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
  * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
  */

 #include <linux/i2c.h>
 #include <linux/leds.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/led-lm3530.h>
 #include <linux/types.h>

 #define LM3530_LED_DEV "lcd-backlight"
 #define LM3530_NAME "lm3530-led"

 #define LM3530_GEN_CONFIG		0x10
 #define LM3530_ALS_CONFIG		0x20
 #define LM3530_BRT_RAMP_RATE		0x30
 #define LM3530_ALS_ZONE_REG		0x40
 #define LM3530_ALS_IMP_SELECT		0x41
 #define LM3530_BRT_CTRL_REG		0xA0
 #define LM3530_ALS_ZB0_REG		0x60
 #define LM3530_ALS_ZB1_REG		0x61
 #define LM3530_ALS_ZB2_REG		0x62
 #define LM3530_ALS_ZB3_REG		0x63
 #define LM3530_ALS_Z0T_REG		0x70
 #define LM3530_ALS_Z1T_REG		0x71
 #define LM3530_ALS_Z2T_REG		0x72
 #define LM3530_ALS_Z3T_REG		0x73
 #define LM3530_ALS_Z4T_REG		0x74
 #define LM3530_REG_MAX			15

 /* General Control Register */
 #define LM3530_EN_I2C_SHIFT		(0)
 #define LM3530_RAMP_LAW_SHIFT		(1)
 #define LM3530_MAX_CURR_SHIFT		(2)
 #define LM3530_EN_PWM_SHIFT		(5)
 #define LM3530_PWM_POL_SHIFT		(6)
 #define LM3530_EN_PWM_SIMPLE_SHIFT	(7)

 #define LM3530_ENABLE_I2C		(1 << LM3530_EN_I2C_SHIFT)
 #define LM3530_ENABLE_PWM		(1 << LM3530_EN_PWM_SHIFT)
 #define LM3530_POL_LOW			(1 << LM3530_PWM_POL_SHIFT)
 #define LM3530_ENABLE_PWM_SIMPLE	(1 << LM3530_EN_PWM_SIMPLE_SHIFT)

 /* ALS Config Register Options */
 #define LM3530_ALS_AVG_TIME_SHIFT	(0)
 #define LM3530_EN_ALS_SHIFT		(3)
 #define LM3530_ALS_SEL_SHIFT		(5)

 #define LM3530_ENABLE_ALS		(3 << LM3530_EN_ALS_SHIFT)

 /* Brightness Ramp Rate Register */
 #define LM3530_BRT_RAMP_FALL_SHIFT	(0)
 #define LM3530_BRT_RAMP_RISE_SHIFT	(3)

 /* ALS Resistor Select */
 #define LM3530_ALS1_IMP_SHIFT		(0)
 #define LM3530_ALS2_IMP_SHIFT		(4)

 /* Zone Boundary Register defaults */
 #define LM3530_DEF_ZB_0			(0x33)
 #define LM3530_DEF_ZB_1			(0x66)
 #define LM3530_DEF_ZB_2			(0x99)
 #define LM3530_DEF_ZB_3			(0xCC)

 /* Zone Target Register defaults */
 #define LM3530_DEF_ZT_0			(0x19)
 #define LM3530_DEF_ZT_1			(0x33)
 #define LM3530_DEF_ZT_2			(0x4C)
 #define LM3530_DEF_ZT_3			(0x66)
 #define LM3530_DEF_ZT_4			(0x7F)

 struct lm3530_mode_map {
 	const char *mode;
 	enum lm3530_mode mode_val;
 };

 static struct lm3530_mode_map mode_map[] = {
 	{ "man", LM3530_BL_MODE_MANUAL },
 	{ "als", LM3530_BL_MODE_ALS },
 	{ "pwm", LM3530_BL_MODE_PWM },
 };

 /**
  * struct lm3530_data
  * @led_dev: led class device
  * @client: i2c client
  * @pdata: LM3530 platform data
  * @mode: mode of operation - manual, ALS, PWM
  */
 struct lm3530_data {
 	struct led_classdev led_dev;
 	struct i2c_client *client;
 	struct lm3530_platform_data *pdata;
 	enum lm3530_mode mode;
 };

 static const u8 lm3530_reg[LM3530_REG_MAX] = {
 	LM3530_GEN_CONFIG,
 	LM3530_ALS_CONFIG,
 	LM3530_BRT_RAMP_RATE,
 	LM3530_ALS_ZONE_REG,
 	LM3530_ALS_IMP_SELECT,
 	LM3530_BRT_CTRL_REG,
 	LM3530_ALS_ZB0_REG,
 	LM3530_ALS_ZB1_REG,
 	LM3530_ALS_ZB2_REG,
 	LM3530_ALS_ZB3_REG,
 	LM3530_ALS_Z0T_REG,
 	LM3530_ALS_Z1T_REG,
 	LM3530_ALS_Z2T_REG,
 	LM3530_ALS_Z3T_REG,
 	LM3530_ALS_Z4T_REG,
 };

 static int lm3530_get_mode_from_str(const char *str)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
 		if (sysfs_streq(str, mode_map[i].mode))
 			return mode_map[i].mode_val;

 	return -1;
 }

 static int lm3530_init_registers(struct lm3530_data *drvdata)
 {
 	int ret = 0;
 	int i;
 	u8 gen_config;
 	u8 als_config = 0;
 	u8 brt_ramp;
 	u8 als_imp_sel = 0;
 	u8 brightness;
 	u8 reg_val[LM3530_REG_MAX];
 	struct lm3530_platform_data *pltfm = drvdata->pdata;
 	struct i2c_client *client = drvdata->client;

 	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
 			((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);

 	if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
 	    drvdata->mode == LM3530_BL_MODE_ALS)
 		gen_config |= (LM3530_ENABLE_I2C);

 	if (drvdata->mode == LM3530_BL_MODE_ALS) {
 		als_config =
 			(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
 			(LM3530_ENABLE_ALS) |
 			(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);

 		als_imp_sel =
 			(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
 			(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
 	}

 	if (drvdata->mode == LM3530_BL_MODE_PWM)
 		gen_config |= (LM3530_ENABLE_PWM) |
 				(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
 				(LM3530_ENABLE_PWM_SIMPLE);

 	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);

 	brightness = pltfm->brt_val;

 	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
 	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
 	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */
 	reg_val[3] = 0x00;		/* LM3530_ALS_ZONE_REG */
 	reg_val[4] = als_imp_sel;	/* LM3530_ALS_IMP_SELECT */
 	reg_val[5] = brightness;	/* LM3530_BRT_CTRL_REG */
 	reg_val[6] = LM3530_DEF_ZB_0;	/* LM3530_ALS_ZB0_REG */
 	reg_val[7] = LM3530_DEF_ZB_1;	/* LM3530_ALS_ZB1_REG */
 	reg_val[8] = LM3530_DEF_ZB_2;	/* LM3530_ALS_ZB2_REG */
 	reg_val[9] = LM3530_DEF_ZB_3;	/* LM3530_ALS_ZB3_REG */
 	reg_val[10] = LM3530_DEF_ZT_0;	/* LM3530_ALS_Z0T_REG */
 	reg_val[11] = LM3530_DEF_ZT_1;	/* LM3530_ALS_Z1T_REG */
 	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */
 	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */
 	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */

 	for (i = 0; i < LM3530_REG_MAX; i++) {
 		ret = i2c_smbus_write_byte_data(client,
 				lm3530_reg[i], reg_val[i]);
 		if (ret)
 			break;
 	}

 	return ret;
 }

 static void lm3530_brightness_set(struct led_classdev *led_cdev,
 				     enum led_brightness brt_val)
 {
 	int err;
 	struct lm3530_data *drvdata =
 	    container_of(led_cdev, struct lm3530_data, led_dev);

 	switch (drvdata->mode) {
 	case LM3530_BL_MODE_MANUAL:

 		/* set the brightness in brightness control register*/
 		err = i2c_smbus_write_byte_data(drvdata->client,
 				LM3530_BRT_CTRL_REG, brt_val / 2);
 		if (err)
 			dev_err(&drvdata->client->dev,
 				"Unable to set brightness: %d\n", err);
 		break;
 	case LM3530_BL_MODE_ALS:
 		break;
 	case LM3530_BL_MODE_PWM:
 		break;
 	default:
 		break;
 	}
 }


 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 				   *attr, const char *buf, size_t size)
 {
 	int err;
 	struct i2c_client *client = container_of(
 					dev->parent, struct i2c_client, dev);
 	struct lm3530_data *drvdata = i2c_get_clientdata(client);
 	int mode;

 	mode = lm3530_get_mode_from_str(buf);
 	if (mode < 0) {
 		dev_err(dev, "Invalid mode\n");
 		return -EINVAL;
 	}

 	if (mode == LM3530_BL_MODE_MANUAL)
 		drvdata->mode = LM3530_BL_MODE_MANUAL;
 	else if (mode == LM3530_BL_MODE_ALS)
 		drvdata->mode = LM3530_BL_MODE_ALS;
 	else if (mode == LM3530_BL_MODE_PWM) {
 		dev_err(dev, "PWM mode not supported\n");
 		return -EINVAL;
 	}

 	err = lm3530_init_registers(drvdata);
 	if (err) {
 		dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
 		return err;
 	}

 	return sizeof(drvdata->mode);
 }

 static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);

 static int __devinit lm3530_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
 	struct lm3530_platform_data *pdata = client->dev.platform_data;
 	struct lm3530_data *drvdata;
 	int err = 0;

 	if (pdata == NULL) {
 		dev_err(&client->dev, "platform data required\n");
 		err = -ENODEV;
 		goto err_out;
 	}

 	/* BL mode */
 	if (pdata->mode > LM3530_BL_MODE_PWM) {
 		dev_err(&client->dev, "Illegal Mode request\n");
 		err = -EINVAL;
 		goto err_out;
 	}

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
 		err = -EIO;
 		goto err_out;
 	}

 	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
 	if (drvdata == NULL) {
 		err = -ENOMEM;
 		goto err_out;
 	}

 	drvdata->mode = pdata->mode;
 	drvdata->client = client;
 	drvdata->pdata = pdata;
 	drvdata->led_dev.name = LM3530_LED_DEV;
 	drvdata->led_dev.brightness_set = lm3530_brightness_set;

 	i2c_set_clientdata(client, drvdata);

 	err = lm3530_init_registers(drvdata);
 	if (err < 0) {
 		dev_err(&client->dev, "Register Init failed: %d\n", err);
 		err = -ENODEV;
 		goto err_reg_init;
 	}

 	err = led_classdev_register((struct device *)
 				      &client->dev, &drvdata->led_dev);
 	if (err < 0) {
 		dev_err(&client->dev, "Register led class failed: %d\n", err);
 		err = -ENODEV;
 		goto err_class_register;
 	}

 	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
 	if (err < 0) {
 		dev_err(&client->dev, "File device creation failed: %d\n", err);
 		err = -ENODEV;
 		goto err_create_file;
 	}

 	return 0;

 err_create_file:
 	led_classdev_unregister(&drvdata->led_dev);
 err_class_register:
 err_reg_init:
 	kfree(drvdata);
 err_out:
 	return err;
 }

 static int __devexit lm3530_remove(struct i2c_client *client)
 {
 	struct lm3530_data *drvdata = i2c_get_clientdata(client);

 	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
 	led_classdev_unregister(&drvdata->led_dev);
 	kfree(drvdata);
 	return 0;
 }

 static const struct i2c_device_id lm3530_id[] = {
 	{LM3530_NAME, 0},
 	{}
 };

 static struct i2c_driver lm3530_i2c_driver = {
 	.probe = lm3530_probe,
 	.remove = lm3530_remove,
 	.id_table = lm3530_id,
 	.driver = {
 		.name = LM3530_NAME,
 		.owner = THIS_MODULE,
 	},
 };

 static int __init lm3530_init(void)
 {
 	return i2c_add_driver(&lm3530_i2c_driver);
 }

 static void __exit lm3530_exit(void)
 {
 	i2c_del_driver(&lm3530_i2c_driver);
 }

 module_init(lm3530_init);
 module_exit(lm3530_exit);

 MODULE_DESCRIPTION("Back Light driver for LM3530");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
	/*
	* Copyright (C) 2011 ST-Ericsson SA.
	* Copyright (C) 2009 Motorola, Inc.
	*
	* License Terms: GNU General Public License v2
	*
	* Simple driver for National Semiconductor LM3530 Backlight driver chip
	*
	* Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
	* based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
	*/

	#include <linux/i2c.h>
	#include <linux/leds.h>
	#include <linux/slab.h>
	#include <linux/platform_device.h>
	#include <linux/input.h>
	#include <linux/led-lm3530.h>
	#include <linux/types.h>

	#define LM3530_LED_DEV "lcd-backlight"
	#define LM3530_NAME "lm3530-led"

	#define LM3530_GEN_CONFIG 0x10
	#define LM3530_ALS_CONFIG 0x20
	#define LM3530_BRT_RAMP_RATE 0x30
	#define LM3530_ALS_ZONE_REG 0x40
	#define LM3530_ALS_IMP_SELECT 0x41
	#define LM3530_BRT_CTRL_REG 0xA0
	#define LM3530_ALS_ZB0_REG 0x60
	#define LM3530_ALS_ZB1_REG 0x61
	#define LM3530_ALS_ZB2_REG 0x62
	#define LM3530_ALS_ZB3_REG 0x63
	#define LM3530_ALS_Z0T_REG 0x70
	#define LM3530_ALS_Z1T_REG 0x71
	#define LM3530_ALS_Z2T_REG 0x72
	#define LM3530_ALS_Z3T_REG 0x73
	#define LM3530_ALS_Z4T_REG 0x74
	#define LM3530_REG_MAX 15

	/* General Control Register */
	#define LM3530_EN_I2C_SHIFT (0)
	#define LM3530_RAMP_LAW_SHIFT (1)
	#define LM3530_MAX_CURR_SHIFT (2)
	#define LM3530_EN_PWM_SHIFT (5)
	#define LM3530_PWM_POL_SHIFT (6)
	#define LM3530_EN_PWM_SIMPLE_SHIFT (7)

	#define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
	#define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
	#define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
	#define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)

	/* ALS Config Register Options */
	#define LM3530_ALS_AVG_TIME_SHIFT (0)
	#define LM3530_EN_ALS_SHIFT (3)
	#define LM3530_ALS_SEL_SHIFT (5)

	#define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)

	/* Brightness Ramp Rate Register */
	#define LM3530_BRT_RAMP_FALL_SHIFT (0)
	#define LM3530_BRT_RAMP_RISE_SHIFT (3)

	/* ALS Resistor Select */
	#define LM3530_ALS1_IMP_SHIFT (0)
	#define LM3530_ALS2_IMP_SHIFT (4)

	/* Zone Boundary Register defaults */
	#define LM3530_DEF_ZB_0 (0x33)
	#define LM3530_DEF_ZB_1 (0x66)
	#define LM3530_DEF_ZB_2 (0x99)
	#define LM3530_DEF_ZB_3 (0xCC)

	/* Zone Target Register defaults */
	#define LM3530_DEF_ZT_0 (0x19)
	#define LM3530_DEF_ZT_1 (0x33)
	#define LM3530_DEF_ZT_2 (0x4C)
	#define LM3530_DEF_ZT_3 (0x66)
	#define LM3530_DEF_ZT_4 (0x7F)

	struct lm3530_mode_map {
	const char *mode;
	enum lm3530_mode mode_val;
	};

	static struct lm3530_mode_map mode_map[] = {
	{ "man", LM3530_BL_MODE_MANUAL },
	{ "als", LM3530_BL_MODE_ALS },
	{ "pwm", LM3530_BL_MODE_PWM },
	};

	/**
	* struct lm3530_data
	* @led_dev: led class device
	* @client: i2c client
	* @pdata: LM3530 platform data
	* @mode: mode of operation - manual, ALS, PWM
	*/
	struct lm3530_data {
	struct led_classdev led_dev;
	struct i2c_client *client;
	struct lm3530_platform_data *pdata;
	enum lm3530_mode mode;
	};

	static const u8 lm3530_reg[LM3530_REG_MAX] = {
	LM3530_GEN_CONFIG,
	LM3530_ALS_CONFIG,
	LM3530_BRT_RAMP_RATE,
	LM3530_ALS_ZONE_REG,
	LM3530_ALS_IMP_SELECT,
	LM3530_BRT_CTRL_REG,
	LM3530_ALS_ZB0_REG,
	LM3530_ALS_ZB1_REG,
	LM3530_ALS_ZB2_REG,
	LM3530_ALS_ZB3_REG,
	LM3530_ALS_Z0T_REG,
	LM3530_ALS_Z1T_REG,
	LM3530_ALS_Z2T_REG,
	LM3530_ALS_Z3T_REG,
	LM3530_ALS_Z4T_REG,
	};

	static int lm3530_get_mode_from_str(const char *str)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
	if (sysfs_streq(str, mode_map[i].mode))
	return mode_map[i].mode_val;

	return -1;
	}

	static int lm3530_init_registers(struct lm3530_data *drvdata)
	{
	int ret = 0;
	int i;
	u8 gen_config;
	u8 als_config = 0;
	u8 brt_ramp;
	u8 als_imp_sel = 0;
	u8 brightness;
	u8 reg_val[LM3530_REG_MAX];
	struct lm3530_platform_data *pltfm = drvdata->pdata;
	struct i2c_client *client = drvdata->client;

	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) \|
	((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);

	if (drvdata->mode == LM3530_BL_MODE_MANUAL \|\|
	drvdata->mode == LM3530_BL_MODE_ALS)
	gen_config \|= (LM3530_ENABLE_I2C);

	if (drvdata->mode == LM3530_BL_MODE_ALS) {
	als_config =
	(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) \|
	(LM3530_ENABLE_ALS) \|
	(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);

	als_imp_sel =
	(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) \|
	(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
	}

	if (drvdata->mode == LM3530_BL_MODE_PWM)
	gen_config \|= (LM3530_ENABLE_PWM) \|
	(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) \|
	(LM3530_ENABLE_PWM_SIMPLE);

	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) \|
	(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);

	brightness = pltfm->brt_val;

	reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
	reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
	reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
	reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
	reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
	reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
	reg_val[6] = LM3530_DEF_ZB_0; /* LM3530_ALS_ZB0_REG */
	reg_val[7] = LM3530_DEF_ZB_1; /* LM3530_ALS_ZB1_REG */
	reg_val[8] = LM3530_DEF_ZB_2; /* LM3530_ALS_ZB2_REG */
	reg_val[9] = LM3530_DEF_ZB_3; /* LM3530_ALS_ZB3_REG */
	reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
	reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
	reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
	reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
	reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */

	for (i = 0; i < LM3530_REG_MAX; i++) {
	ret = i2c_smbus_write_byte_data(client,
	lm3530_reg[i], reg_val[i]);
	if (ret)
	break;
	}

	return ret;
	}

	static void lm3530_brightness_set(struct led_classdev *led_cdev,
	enum led_brightness brt_val)
	{
	int err;
	struct lm3530_data *drvdata =
	container_of(led_cdev, struct lm3530_data, led_dev);

	switch (drvdata->mode) {
	case LM3530_BL_MODE_MANUAL:

	/* set the brightness in brightness control register*/
	err = i2c_smbus_write_byte_data(drvdata->client,
	LM3530_BRT_CTRL_REG, brt_val / 2);
	if (err)
	dev_err(&drvdata->client->dev,
	"Unable to set brightness: %d\n", err);
	break;
	case LM3530_BL_MODE_ALS:
	break;
	case LM3530_BL_MODE_PWM:
	break;
	default:
	break;
	}
	}


	static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
	attr, const char buf, size_t size)
	{
	int err;
	struct i2c_client *client = container_of(
	dev->parent, struct i2c_client, dev);
	struct lm3530_data *drvdata = i2c_get_clientdata(client);
	int mode;

	mode = lm3530_get_mode_from_str(buf);
	if (mode < 0) {
	dev_err(dev, "Invalid mode\n");
	return -EINVAL;
	}

	if (mode == LM3530_BL_MODE_MANUAL)
	drvdata->mode = LM3530_BL_MODE_MANUAL;
	else if (mode == LM3530_BL_MODE_ALS)
	drvdata->mode = LM3530_BL_MODE_ALS;
	else if (mode == LM3530_BL_MODE_PWM) {
	dev_err(dev, "PWM mode not supported\n");
	return -EINVAL;
	}

	err = lm3530_init_registers(drvdata);
	if (err) {
	dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
	return err;
	}

	return sizeof(drvdata->mode);
	}

	static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);

	static int __devinit lm3530_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct lm3530_platform_data *pdata = client->dev.platform_data;
	struct lm3530_data *drvdata;
	int err = 0;

	if (pdata == NULL) {
	dev_err(&client->dev, "platform data required\n");
	err = -ENODEV;
	goto err_out;
	}

	/* BL mode */
	if (pdata->mode > LM3530_BL_MODE_PWM) {
	dev_err(&client->dev, "Illegal Mode request\n");
	err = -EINVAL;
	goto err_out;
	}

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
	err = -EIO;
	goto err_out;
	}

	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
	if (drvdata == NULL) {
	err = -ENOMEM;
	goto err_out;
	}

	drvdata->mode = pdata->mode;
	drvdata->client = client;
	drvdata->pdata = pdata;
	drvdata->led_dev.name = LM3530_LED_DEV;
	drvdata->led_dev.brightness_set = lm3530_brightness_set;

	i2c_set_clientdata(client, drvdata);

	err = lm3530_init_registers(drvdata);
	if (err < 0) {
	dev_err(&client->dev, "Register Init failed: %d\n", err);
	err = -ENODEV;
	goto err_reg_init;
	}

	err = led_classdev_register((struct device *)
	&client->dev, &drvdata->led_dev);
	if (err < 0) {
	dev_err(&client->dev, "Register led class failed: %d\n", err);
	err = -ENODEV;
	goto err_class_register;
	}

	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
	if (err < 0) {
	dev_err(&client->dev, "File device creation failed: %d\n", err);
	err = -ENODEV;
	goto err_create_file;
	}

	return 0;

	err_create_file:
	led_classdev_unregister(&drvdata->led_dev);
	err_class_register:
	err_reg_init:
	kfree(drvdata);
	err_out:
	return err;
	}

	static int __devexit lm3530_remove(struct i2c_client *client)
	{
	struct lm3530_data *drvdata = i2c_get_clientdata(client);

	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
	led_classdev_unregister(&drvdata->led_dev);
	kfree(drvdata);
	return 0;
	}

	static const struct i2c_device_id lm3530_id[] = {
	{LM3530_NAME, 0},
	{}
	};

	static struct i2c_driver lm3530_i2c_driver = {
	.probe = lm3530_probe,
	.remove = lm3530_remove,
	.id_table = lm3530_id,
	.driver = {
	.name = LM3530_NAME,
	.owner = THIS_MODULE,
	},
	};

	static int __init lm3530_init(void)
	{
	return i2c_add_driver(&lm3530_i2c_driver);
	}

	static void __exit lm3530_exit(void)
	{
	i2c_del_driver(&lm3530_i2c_driver);
	}

	module_init(lm3530_init);
	module_exit(lm3530_exit);

	MODULE_DESCRIPTION("Back Light driver for LM3530");
	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");