drivers/leds/leds-lm3692x.c - linux - Git at Google

 /*
  * TI lm3692x LED Driver
  *
  * Copyright (C) 2017 Texas Instruments
  *
  * Author: Dan Murphy <dmurphy@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.
  *
  * Data sheet is located
  * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
  */

 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <uapi/linux/uleds.h>

 #define LM3692X_REV		0x0
 #define LM3692X_RESET		0x1
 #define LM3692X_EN		0x10
 #define LM3692X_BRT_CTRL	0x11
 #define LM3692X_PWM_CTRL	0x12
 #define LM3692X_BOOST_CTRL	0x13
 #define LM3692X_AUTO_FREQ_HI	0x15
 #define LM3692X_AUTO_FREQ_LO	0x16
 #define LM3692X_BL_ADJ_THRESH	0x17
 #define LM3692X_BRT_LSB		0x18
 #define LM3692X_BRT_MSB		0x19
 #define LM3692X_FAULT_CTRL	0x1e
 #define LM3692X_FAULT_FLAGS	0x1f

 #define LM3692X_SW_RESET	BIT(0)
 #define LM3692X_DEVICE_EN	BIT(0)
 #define LM3692X_LED1_EN		BIT(1)
 #define LM3692X_LED2_EN		BIT(2)

 /* Brightness Control Bits */
 #define LM3692X_BL_ADJ_POL	BIT(0)
 #define LM3692X_RAMP_RATE_125us	0x00
 #define LM3692X_RAMP_RATE_250us	BIT(1)
 #define LM3692X_RAMP_RATE_500us BIT(2)
 #define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
 #define LM3692X_RAMP_RATE_2ms	BIT(3)
 #define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
 #define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
 #define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))
 #define LM3692X_RAMP_EN		BIT(4)
 #define LM3692X_BRHT_MODE_REG	0x00
 #define LM3692X_BRHT_MODE_PWM	BIT(5)
 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
 #define LM3692X_MAP_MODE_EXP	BIT(7)

 /* PWM Register Bits */
 #define LM3692X_PWM_FILTER_100	BIT(0)
 #define LM3692X_PWM_FILTER_150	BIT(1)
 #define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
 #define LM3692X_PWM_HYSTER_2LSB	BIT(3)
 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
 #define LM3692X_PWM_POLARITY	BIT(5)
 #define LM3692X_PWM_SAMP_4MHZ	BIT(6)
 #define LM3692X_PWM_SAMP_24MHZ	BIT(7)

 /* Boost Control Bits */
 #define LM3692X_OCP_PROT_1A	BIT(0)
 #define LM3692X_OCP_PROT_1_25A	BIT(1)
 #define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
 #define LM3692X_OVP_21V		BIT(2)
 #define LM3692X_OVP_25V		BIT(3)
 #define LM3692X_OVP_29V		(BIT(2) | BIT(3))
 #define LM3692X_MIN_IND_22UH	BIT(4)
 #define LM3692X_BOOST_SW_1MHZ	BIT(5)
 #define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)

 /* Fault Control Bits */
 #define LM3692X_FAULT_CTRL_OVP BIT(0)
 #define LM3692X_FAULT_CTRL_OCP BIT(1)
 #define LM3692X_FAULT_CTRL_TSD BIT(2)
 #define LM3692X_FAULT_CTRL_OPEN BIT(3)

 /* Fault Flag Bits */
 #define LM3692X_FAULT_FLAG_OVP BIT(0)
 #define LM3692X_FAULT_FLAG_OCP BIT(1)
 #define LM3692X_FAULT_FLAG_TSD BIT(2)
 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
 #define LM3692X_FAULT_FLAG_OPEN BIT(4)

 /**
  * struct lm3692x_led -
  * @lock - Lock for reading/writing the device
  * @client - Pointer to the I2C client
  * @led_dev - LED class device pointer
  * @regmap - Devices register map
  * @enable_gpio - VDDIO/EN gpio to enable communication interface
  * @regulator - LED supply regulator pointer
  * @label - LED label
  */
 struct lm3692x_led {
 	struct mutex lock;
 	struct i2c_client *client;
 	struct led_classdev led_dev;
 	struct regmap *regmap;
 	struct gpio_desc *enable_gpio;
 	struct regulator *regulator;
 	char label[LED_MAX_NAME_SIZE];
 };

 static const struct reg_default lm3692x_reg_defs[] = {
 	{LM3692X_EN, 0xf},
 	{LM3692X_BRT_CTRL, 0x61},
 	{LM3692X_PWM_CTRL, 0x73},
 	{LM3692X_BOOST_CTRL, 0x6f},
 	{LM3692X_AUTO_FREQ_HI, 0x0},
 	{LM3692X_AUTO_FREQ_LO, 0x0},
 	{LM3692X_BL_ADJ_THRESH, 0x0},
 	{LM3692X_BRT_LSB, 0x7},
 	{LM3692X_BRT_MSB, 0xff},
 	{LM3692X_FAULT_CTRL, 0x7},
 };

 static const struct regmap_config lm3692x_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,

 	.max_register = LM3692X_FAULT_FLAGS,
 	.reg_defaults = lm3692x_reg_defs,
 	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
 	.cache_type = REGCACHE_RBTREE,
 };

 static int lm3692x_fault_check(struct lm3692x_led *led)
 {
 	int ret;
 	unsigned int read_buf;

 	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 	if (ret)
 		return ret;

 	if (read_buf)
 		dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);

 	/* The first read may clear the fault.  Check again to see if the fault
 	 * still exits and return that value.
 	 */
 	regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 	if (read_buf)
 		dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
 			read_buf);

 	return read_buf;
 }

 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
 				enum led_brightness brt_val)
 {
 	struct lm3692x_led *led =
 			container_of(led_cdev, struct lm3692x_led, led_dev);
 	int ret;
 	int led_brightness_lsb = (brt_val >> 5);

 	mutex_lock(&led->lock);

 	ret = lm3692x_fault_check(led);
 	if (ret) {
 		dev_err(&led->client->dev, "Cannot read/clear faults\n");
 		goto out;
 	}

 	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 	if (ret) {
 		dev_err(&led->client->dev, "Cannot write MSB\n");
 		goto out;
 	}

 	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 	if (ret) {
 		dev_err(&led->client->dev, "Cannot write LSB\n");
 		goto out;
 	}
 out:
 	mutex_unlock(&led->lock);
 	return ret;
 }

 static int lm3692x_init(struct lm3692x_led *led)
 {
 	int ret;

 	if (led->regulator) {
 		ret = regulator_enable(led->regulator);
 		if (ret) {
 			dev_err(&led->client->dev,
 				"Failed to enable regulator\n");
 			return ret;
 		}
 	}

 	if (led->enable_gpio)
 		gpiod_direction_output(led->enable_gpio, 1);

 	ret = lm3692x_fault_check(led);
 	if (ret) {
 		dev_err(&led->client->dev, "Cannot read/clear faults\n");
 		goto out;
 	}

 	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 	if (ret)
 		goto out;

 	/*
 	 * For glitch free operation, the following data should
 	 * only be written while device enable bit is 0
 	 * per Section 7.5.14 of the data sheet
 	 */
 	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 	if (ret)
 		goto out;

 	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
 			LM3692X_BRHT_MODE_RAMP_MULTI |
 			LM3692X_BL_ADJ_POL |
 			LM3692X_RAMP_RATE_250us);
 	if (ret)
 		goto out;

 	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 	if (ret)
 		goto out;

 	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 	if (ret)
 		goto out;

 	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 	if (ret)
 		goto out;

 	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 			LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
 	if (ret)
 		goto out;

 	return ret;
 out:
 	dev_err(&led->client->dev, "Fail writing initialization values\n");

 	if (led->enable_gpio)
 		gpiod_direction_output(led->enable_gpio, 0);

 	if (led->regulator) {
 		ret = regulator_disable(led->regulator);
 		if (ret)
 			dev_err(&led->client->dev,
 				"Failed to disable regulator\n");
 	}

 	return ret;
 }

 static int lm3692x_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret;
 	struct lm3692x_led *led;
 	struct device_node *np = client->dev.of_node;
 	struct device_node *child_node;
 	const char *name;

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

 	for_each_available_child_of_node(np, child_node) {
 		led->led_dev.default_trigger = of_get_property(child_node,
 						    "linux,default-trigger",
 						    NULL);

 		ret = of_property_read_string(child_node, "label", &name);
 		if (!ret)
 			snprintf(led->label, sizeof(led->label),
 				 "%s:%s", id->name, name);
 		else
 			snprintf(led->label, sizeof(led->label),
 				 "%s::backlight_cluster", id->name);
 	};

 	led->enable_gpio = devm_gpiod_get_optional(&client->dev,
 						   "enable", GPIOD_OUT_LOW);
 	if (IS_ERR(led->enable_gpio)) {
 		ret = PTR_ERR(led->enable_gpio);
 		dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 		return ret;
 	}

 	led->regulator = devm_regulator_get(&client->dev, "vled");
 	if (IS_ERR(led->regulator))
 		led->regulator = NULL;

 	led->client = client;
 	led->led_dev.name = led->label;
 	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;

 	mutex_init(&led->lock);

 	i2c_set_clientdata(client, led);

 	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 	if (IS_ERR(led->regmap)) {
 		ret = PTR_ERR(led->regmap);
 		dev_err(&client->dev, "Failed to allocate register map: %d\n",
 			ret);
 		return ret;
 	}

 	ret = lm3692x_init(led);
 	if (ret)
 		return ret;

 	ret = devm_led_classdev_register(&client->dev, &led->led_dev);
 	if (ret) {
 		dev_err(&client->dev, "led register err: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static int lm3692x_remove(struct i2c_client *client)
 {
 	struct lm3692x_led *led = i2c_get_clientdata(client);
 	int ret;

 	if (led->enable_gpio)
 		gpiod_direction_output(led->enable_gpio, 0);

 	if (led->regulator) {
 		ret = regulator_disable(led->regulator);
 		if (ret)
 			dev_err(&led->client->dev,
 				"Failed to disable regulator\n");
 	}

 	mutex_destroy(&led->lock);

 	return 0;
 }

 static const struct i2c_device_id lm3692x_id[] = {
 	{ "lm36922", 0 },
 	{ "lm36923", 1 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, lm3692x_id);

 static const struct of_device_id of_lm3692x_leds_match[] = {
 	{ .compatible = "ti,lm36922", },
 	{ .compatible = "ti,lm36923", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);

 static struct i2c_driver lm3692x_driver = {
 	.driver = {
 		.name	= "lm3692x",
 		.of_match_table = of_lm3692x_leds_match,
 	},
 	.probe		= lm3692x_probe,
 	.remove		= lm3692x_remove,
 	.id_table	= lm3692x_id,
 };
 module_i2c_driver(lm3692x_driver);

 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* TI lm3692x LED Driver
	*
	* Copyright (C) 2017 Texas Instruments
	*
	* Author: Dan Murphy <dmurphy@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.
	*
	* Data sheet is located
	* http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
	*/

	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/regmap.h>
	#include <linux/regulator/consumer.h>
	#include <linux/slab.h>
	#include <uapi/linux/uleds.h>

	#define LM3692X_REV 0x0
	#define LM3692X_RESET 0x1
	#define LM3692X_EN 0x10
	#define LM3692X_BRT_CTRL 0x11
	#define LM3692X_PWM_CTRL 0x12
	#define LM3692X_BOOST_CTRL 0x13
	#define LM3692X_AUTO_FREQ_HI 0x15
	#define LM3692X_AUTO_FREQ_LO 0x16
	#define LM3692X_BL_ADJ_THRESH 0x17
	#define LM3692X_BRT_LSB 0x18
	#define LM3692X_BRT_MSB 0x19
	#define LM3692X_FAULT_CTRL 0x1e
	#define LM3692X_FAULT_FLAGS 0x1f

	#define LM3692X_SW_RESET BIT(0)
	#define LM3692X_DEVICE_EN BIT(0)
	#define LM3692X_LED1_EN BIT(1)
	#define LM3692X_LED2_EN BIT(2)

	/* Brightness Control Bits */
	#define LM3692X_BL_ADJ_POL BIT(0)
	#define LM3692X_RAMP_RATE_125us 0x00
	#define LM3692X_RAMP_RATE_250us BIT(1)
	#define LM3692X_RAMP_RATE_500us BIT(2)
	#define LM3692X_RAMP_RATE_1ms (BIT(1) \| BIT(2))
	#define LM3692X_RAMP_RATE_2ms BIT(3)
	#define LM3692X_RAMP_RATE_4ms (BIT(3) \| BIT(1))
	#define LM3692X_RAMP_RATE_8ms (BIT(2) \| BIT(3))
	#define LM3692X_RAMP_RATE_16ms (BIT(1) \| BIT(2) \| BIT(3))
	#define LM3692X_RAMP_EN BIT(4)
	#define LM3692X_BRHT_MODE_REG 0x00
	#define LM3692X_BRHT_MODE_PWM BIT(5)
	#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
	#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) \| BIT(6))
	#define LM3692X_MAP_MODE_EXP BIT(7)

	/* PWM Register Bits */
	#define LM3692X_PWM_FILTER_100 BIT(0)
	#define LM3692X_PWM_FILTER_150 BIT(1)
	#define LM3692X_PWM_FILTER_200 (BIT(0) \| BIT(1))
	#define LM3692X_PWM_HYSTER_1LSB BIT(2)
	#define LM3692X_PWM_HYSTER_2LSB BIT(3)
	#define LM3692X_PWM_HYSTER_3LSB (BIT(3) \| BIT(2))
	#define LM3692X_PWM_HYSTER_4LSB BIT(4)
	#define LM3692X_PWM_HYSTER_5LSB (BIT(4) \| BIT(2))
	#define LM3692X_PWM_HYSTER_6LSB (BIT(4) \| BIT(3))
	#define LM3692X_PWM_POLARITY BIT(5)
	#define LM3692X_PWM_SAMP_4MHZ BIT(6)
	#define LM3692X_PWM_SAMP_24MHZ BIT(7)

	/* Boost Control Bits */
	#define LM3692X_OCP_PROT_1A BIT(0)
	#define LM3692X_OCP_PROT_1_25A BIT(1)
	#define LM3692X_OCP_PROT_1_5A (BIT(0) \| BIT(1))
	#define LM3692X_OVP_21V BIT(2)
	#define LM3692X_OVP_25V BIT(3)
	#define LM3692X_OVP_29V (BIT(2) \| BIT(3))
	#define LM3692X_MIN_IND_22UH BIT(4)
	#define LM3692X_BOOST_SW_1MHZ BIT(5)
	#define LM3692X_BOOST_SW_NO_SHIFT BIT(6)

	/* Fault Control Bits */
	#define LM3692X_FAULT_CTRL_OVP BIT(0)
	#define LM3692X_FAULT_CTRL_OCP BIT(1)
	#define LM3692X_FAULT_CTRL_TSD BIT(2)
	#define LM3692X_FAULT_CTRL_OPEN BIT(3)

	/* Fault Flag Bits */
	#define LM3692X_FAULT_FLAG_OVP BIT(0)
	#define LM3692X_FAULT_FLAG_OCP BIT(1)
	#define LM3692X_FAULT_FLAG_TSD BIT(2)
	#define LM3692X_FAULT_FLAG_SHRT BIT(3)
	#define LM3692X_FAULT_FLAG_OPEN BIT(4)

	/**
	* struct lm3692x_led -
	* @lock - Lock for reading/writing the device
	* @client - Pointer to the I2C client
	* @led_dev - LED class device pointer
	* @regmap - Devices register map
	* @enable_gpio - VDDIO/EN gpio to enable communication interface
	* @regulator - LED supply regulator pointer
	* @label - LED label
	*/
	struct lm3692x_led {
	struct mutex lock;
	struct i2c_client *client;
	struct led_classdev led_dev;
	struct regmap *regmap;
	struct gpio_desc *enable_gpio;
	struct regulator *regulator;
	char label[LED_MAX_NAME_SIZE];
	};

	static const struct reg_default lm3692x_reg_defs[] = {
	{LM3692X_EN, 0xf},
	{LM3692X_BRT_CTRL, 0x61},
	{LM3692X_PWM_CTRL, 0x73},
	{LM3692X_BOOST_CTRL, 0x6f},
	{LM3692X_AUTO_FREQ_HI, 0x0},
	{LM3692X_AUTO_FREQ_LO, 0x0},
	{LM3692X_BL_ADJ_THRESH, 0x0},
	{LM3692X_BRT_LSB, 0x7},
	{LM3692X_BRT_MSB, 0xff},
	{LM3692X_FAULT_CTRL, 0x7},
	};

	static const struct regmap_config lm3692x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = LM3692X_FAULT_FLAGS,
	.reg_defaults = lm3692x_reg_defs,
	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
	.cache_type = REGCACHE_RBTREE,
	};

	static int lm3692x_fault_check(struct lm3692x_led *led)
	{
	int ret;
	unsigned int read_buf;

	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
	if (ret)
	return ret;

	if (read_buf)
	dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);

	/* The first read may clear the fault. Check again to see if the fault
	* still exits and return that value.
	*/
	regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
	if (read_buf)
	dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
	read_buf);

	return read_buf;
	}

	static int lm3692x_brightness_set(struct led_classdev *led_cdev,
	enum led_brightness brt_val)
	{
	struct lm3692x_led *led =
	container_of(led_cdev, struct lm3692x_led, led_dev);
	int ret;
	int led_brightness_lsb = (brt_val >> 5);

	mutex_lock(&led->lock);

	ret = lm3692x_fault_check(led);
	if (ret) {
	dev_err(&led->client->dev, "Cannot read/clear faults\n");
	goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
	if (ret) {
	dev_err(&led->client->dev, "Cannot write MSB\n");
	goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
	if (ret) {
	dev_err(&led->client->dev, "Cannot write LSB\n");
	goto out;
	}
	out:
	mutex_unlock(&led->lock);
	return ret;
	}

	static int lm3692x_init(struct lm3692x_led *led)
	{
	int ret;

	if (led->regulator) {
	ret = regulator_enable(led->regulator);
	if (ret) {
	dev_err(&led->client->dev,
	"Failed to enable regulator\n");
	return ret;
	}
	}

	if (led->enable_gpio)
	gpiod_direction_output(led->enable_gpio, 1);

	ret = lm3692x_fault_check(led);
	if (ret) {
	dev_err(&led->client->dev, "Cannot read/clear faults\n");
	goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
	if (ret)
	goto out;

	/*
	* For glitch free operation, the following data should
	* only be written while device enable bit is 0
	* per Section 7.5.14 of the data sheet
	*/
	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
	LM3692X_PWM_FILTER_100 \| LM3692X_PWM_SAMP_24MHZ);
	if (ret)
	goto out;

	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
	LM3692X_BRHT_MODE_RAMP_MULTI \|
	LM3692X_BL_ADJ_POL \|
	LM3692X_RAMP_RATE_250us);
	if (ret)
	goto out;

	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
	if (ret)
	goto out;

	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
	if (ret)
	goto out;

	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
	if (ret)
	goto out;

	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
	LM3692X_BL_ADJ_POL \| LM3692X_PWM_HYSTER_4LSB);
	if (ret)
	goto out;

	return ret;
	out:
	dev_err(&led->client->dev, "Fail writing initialization values\n");

	if (led->enable_gpio)
	gpiod_direction_output(led->enable_gpio, 0);

	if (led->regulator) {
	ret = regulator_disable(led->regulator);
	if (ret)
	dev_err(&led->client->dev,
	"Failed to disable regulator\n");
	}

	return ret;
	}

	static int lm3692x_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct lm3692x_led *led;
	struct device_node *np = client->dev.of_node;
	struct device_node *child_node;
	const char *name;

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

	for_each_available_child_of_node(np, child_node) {
	led->led_dev.default_trigger = of_get_property(child_node,
	"linux,default-trigger",
	NULL);

	ret = of_property_read_string(child_node, "label", &name);
	if (!ret)
	snprintf(led->label, sizeof(led->label),
	"%s:%s", id->name, name);
	else
	snprintf(led->label, sizeof(led->label),
	"%s::backlight_cluster", id->name);
	};

	led->enable_gpio = devm_gpiod_get_optional(&client->dev,
	"enable", GPIOD_OUT_LOW);
	if (IS_ERR(led->enable_gpio)) {
	ret = PTR_ERR(led->enable_gpio);
	dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
	return ret;
	}

	led->regulator = devm_regulator_get(&client->dev, "vled");
	if (IS_ERR(led->regulator))
	led->regulator = NULL;

	led->client = client;
	led->led_dev.name = led->label;
	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;

	mutex_init(&led->lock);

	i2c_set_clientdata(client, led);

	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
	if (IS_ERR(led->regmap)) {
	ret = PTR_ERR(led->regmap);
	dev_err(&client->dev, "Failed to allocate register map: %d\n",
	ret);
	return ret;
	}

	ret = lm3692x_init(led);
	if (ret)
	return ret;

	ret = devm_led_classdev_register(&client->dev, &led->led_dev);
	if (ret) {
	dev_err(&client->dev, "led register err: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static int lm3692x_remove(struct i2c_client *client)
	{
	struct lm3692x_led *led = i2c_get_clientdata(client);
	int ret;

	if (led->enable_gpio)
	gpiod_direction_output(led->enable_gpio, 0);

	if (led->regulator) {
	ret = regulator_disable(led->regulator);
	if (ret)
	dev_err(&led->client->dev,
	"Failed to disable regulator\n");
	}

	mutex_destroy(&led->lock);

	return 0;
	}

	static const struct i2c_device_id lm3692x_id[] = {
	{ "lm36922", 0 },
	{ "lm36923", 1 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, lm3692x_id);

	static const struct of_device_id of_lm3692x_leds_match[] = {
	{ .compatible = "ti,lm36922", },
	{ .compatible = "ti,lm36923", },
	{},
	};
	MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);

	static struct i2c_driver lm3692x_driver = {
	.driver = {
	.name = "lm3692x",
	.of_match_table = of_lm3692x_leds_match,
	},
	.probe = lm3692x_probe,
	.remove = lm3692x_remove,
	.id_table = lm3692x_id,
	};
	module_i2c_driver(lm3692x_driver);

	MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
	MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
	MODULE_LICENSE("GPL v2");