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Commit 9699cb6b authored by Dan Murphy's avatar Dan Murphy Committed by Jacek Anaszewski
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leds: lm3692x: Introduce LM3692x dual string driver 

Introducing the LM3692x Dual-String white LED driver.

Data sheet is located
http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf



Signed-off-by: default avatarDan Murphy <dmurphy@ti.com>
Signed-off-by: default avatarJacek Anaszewski <jacek.anaszewski@gmail.com>
parent 1d9aa24b

drivers/leds/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -137,6 +137,13 @@ config LEDS_LM3642 
	  converter plus 1.5A constant current driver for a high-current

	  white LED.



config LEDS_LM3692X

	tristate "LED support for LM3692x Chips"

	depends on LEDS_CLASS && I2C && OF

	select REGMAP_I2C

	help

	  This option enables support for the TI LM3692x family

	  of white LED string drivers used for backlighting.



config LEDS_LOCOMO

	tristate "LED Support for Locomo device"

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o 
obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o

obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o

obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o

obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o



# LED SPI Drivers

obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

drivers/leds/leds-lm3692x.c

0 → 100644
+393 −0
Original line number Diff line number Diff line 
/*

 * 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");