Commit 57a53297 authored by Dan Murphy's avatar Dan Murphy Committed by Jacek Anaszewski
Browse files

leds: lm3601x: Introduce the lm3601x LED driver 

Introduce the family of LED devices that can
drive a torch, strobe or IR LED.

The LED driver can be configured with a strobe
timer to execute a strobe flash.  The IR LED
brightness is controlled via the torch brightness
register.

The data sheet for each the LM36010 and LM36011
LED drivers can be found here:
http://www.ti.com/product/LM36010
http://www.ti.com/product/LM36011



Signed-off-by: default avatarDan Murphy <dmurphy@ti.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarJacek Anaszewski <jacek.anaszewski@gmail.com>
parent 2f8270de

drivers/leds/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -158,6 +158,15 @@ config LEDS_LM3692X 
	  This option enables support for the TI LM3692x family

	  of white LED string drivers used for backlighting.



config LEDS_LM3601X

	tristate "LED support for LM3601x Chips"

	depends on LEDS_CLASS && I2C

	depends on LEDS_CLASS_FLASH

	select REGMAP_I2C

	help

	  This option enables support for the TI LM3601x family

	  of flash, torch and indicator classes.



config LEDS_LOCOMO

	tristate "LED Support for Locomo device"

	depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_NIC78BX) += leds-nic78bx.o 
obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o

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

obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o

obj-$(CONFIG_LEDS_LM3601X)		+= leds-lm3601x.o



# LED SPI Drivers

obj-$(CONFIG_LEDS_CR0014114)		+= leds-cr0014114.o

drivers/leds/leds-lm3601x.c

0 → 100644
+487 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Flash and torch driver for Texas Instruments LM3601X LED

// Flash driver chip family

// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/



#include <linux/delay.h>

#include <linux/i2c.h>

#include <linux/leds.h>

#include <linux/led-class-flash.h>

#include <linux/module.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <uapi/linux/uleds.h>



#define LM3601X_LED_IR		0x0

#define LM3601X_LED_TORCH	0x1



/* Registers */

#define LM3601X_ENABLE_REG	0x01

#define LM3601X_CFG_REG		0x02

#define LM3601X_LED_FLASH_REG	0x03

#define LM3601X_LED_TORCH_REG	0x04

#define LM3601X_FLAGS_REG	0x05

#define LM3601X_DEV_ID_REG	0x06



#define LM3601X_SW_RESET	BIT(7)



/* Enable Mode bits */

#define LM3601X_MODE_STANDBY	0x00

#define LM3601X_MODE_IR_DRV	BIT(0)

#define LM3601X_MODE_TORCH	BIT(1)

#define LM3601X_MODE_STROBE	(BIT(0) | BIT(1))

#define LM3601X_STRB_EN		BIT(2)

#define LM3601X_STRB_EDGE_TRIG	BIT(3)

#define LM3601X_IVFM_EN		BIT(4)



#define LM36010_BOOST_LIMIT_28	BIT(5)

#define LM36010_BOOST_FREQ_4MHZ	BIT(6)

#define LM36010_BOOST_MODE_PASS	BIT(7)



/* Flag Mask */

#define LM3601X_FLASH_TIME_OUT	BIT(0)

#define LM3601X_UVLO_FAULT	BIT(1)

#define LM3601X_THERM_SHUTDOWN	BIT(2)

#define LM3601X_THERM_CURR	BIT(3)

#define LM36010_CURR_LIMIT	BIT(4)

#define LM3601X_SHORT_FAULT	BIT(5)

#define LM3601X_IVFM_TRIP	BIT(6)

#define LM36010_OVP_FAULT	BIT(7)



#define LM3601X_MAX_TORCH_I_UA	376000

#define LM3601X_MIN_TORCH_I_UA	2400

#define LM3601X_TORCH_REG_DIV	2965



#define LM3601X_MAX_STROBE_I_UA	1500000

#define LM3601X_MIN_STROBE_I_UA	11000

#define LM3601X_STROBE_REG_DIV	11800



#define LM3601X_TIMEOUT_MASK	0x1e

#define LM3601X_ENABLE_MASK	(LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)



#define LM3601X_LOWER_STEP_US	40000

#define LM3601X_UPPER_STEP_US	200000

#define LM3601X_MIN_TIMEOUT_US	40000

#define LM3601X_MAX_TIMEOUT_US	1600000

#define LM3601X_TIMEOUT_XOVER_US 400000



enum lm3601x_type {

	CHIP_LM36010 = 0,

	CHIP_LM36011,

};



/**

 * struct lm3601x_led -

 * @fled_cdev: flash LED class device pointer

 * @client: Pointer to the I2C client

 * @regmap: Devices register map

 * @lock: Lock for reading/writing the device

 * @led_name: LED label for the Torch or IR LED

 * @flash_timeout: the timeout for the flash

 * @last_flag: last known flags register value

 * @torch_current_max: maximum current for the torch

 * @flash_current_max: maximum current for the flash

 * @max_flash_timeout: maximum timeout for the flash

 * @led_mode: The mode to enable either IR or Torch

 */

struct lm3601x_led {

	struct led_classdev_flash fled_cdev;

	struct i2c_client *client;

	struct regmap *regmap;

	struct mutex lock;



	char led_name[LED_MAX_NAME_SIZE];



	unsigned int flash_timeout;

	unsigned int last_flag;



	u32 torch_current_max;

	u32 flash_current_max;

	u32 max_flash_timeout;



	u32 led_mode;

};



static const struct reg_default lm3601x_regmap_defs[] = {

	{ LM3601X_ENABLE_REG, 0x20 },

	{ LM3601X_CFG_REG, 0x15 },

	{ LM3601X_LED_FLASH_REG, 0x00 },

	{ LM3601X_LED_TORCH_REG, 0x00 },

};



static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)

{

	switch (reg) {

	case LM3601X_FLAGS_REG:

		return true;

	default:

		return false;

	}

}



static const struct regmap_config lm3601x_regmap = {

	.reg_bits = 8,

	.val_bits = 8,



	.max_register = LM3601X_DEV_ID_REG,

	.reg_defaults = lm3601x_regmap_defs,

	.num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),

	.cache_type = REGCACHE_RBTREE,

	.volatile_reg = lm3601x_volatile_reg,

};



static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)

{

	return container_of(fled_cdev, struct lm3601x_led, fled_cdev);

}



static int lm3601x_read_faults(struct lm3601x_led *led)

{

	int flags_val;

	int ret;



	ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);

	if (ret < 0)

		return -EIO;



	led->last_flag = 0;



	if (flags_val & LM36010_OVP_FAULT)

		led->last_flag |= LED_FAULT_OVER_VOLTAGE;



	if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))

		led->last_flag |= LED_FAULT_OVER_TEMPERATURE;



	if (flags_val & LM3601X_SHORT_FAULT)

		led->last_flag |= LED_FAULT_SHORT_CIRCUIT;



	if (flags_val & LM36010_CURR_LIMIT)

		led->last_flag |= LED_FAULT_OVER_CURRENT;



	if (flags_val & LM3601X_UVLO_FAULT)

		led->last_flag |= LED_FAULT_UNDER_VOLTAGE;



	if (flags_val & LM3601X_IVFM_TRIP)

		led->last_flag |= LED_FAULT_INPUT_VOLTAGE;



	if (flags_val & LM3601X_THERM_SHUTDOWN)

		led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;



	return led->last_flag;

}



static int lm3601x_brightness_set(struct led_classdev *cdev,

					enum led_brightness brightness)

{

	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

	int ret, led_mode_val;



	mutex_lock(&led->lock);



	ret = lm3601x_read_faults(led);

	if (ret < 0)

		goto out;



	if (led->led_mode == LM3601X_LED_TORCH)

		led_mode_val = LM3601X_MODE_TORCH;

	else

		led_mode_val = LM3601X_MODE_IR_DRV;



	if (brightness == LED_OFF) {

		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

					led_mode_val, LED_OFF);

		goto out;

	}



	ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);

	if (ret < 0)

		goto out;



	ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

				LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,

				led_mode_val);

out:

	mutex_unlock(&led->lock);

	return ret;

}



static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,

				bool state)

{

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

	int timeout_reg_val;

	int current_timeout;

	int ret;



	mutex_lock(&led->lock);



	ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);

	if (ret < 0)

		goto out;



	if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)

		timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;

	else

		timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;



	if (led->flash_timeout != current_timeout)

		ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,

					LM3601X_TIMEOUT_MASK, timeout_reg_val);



	if (state)

		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

					LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,

					LM3601X_MODE_STROBE);

	else

		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

					LM3601X_MODE_STROBE, LED_OFF);



	ret = lm3601x_read_faults(led);

out:

	mutex_unlock(&led->lock);

	return ret;

}



static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,

					u32 brightness)

{

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

	u8 brightness_val;

	int ret;



	mutex_lock(&led->lock);

	ret = lm3601x_read_faults(led);

	if (ret < 0)

		goto out;



	if (brightness == LED_OFF) {

		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

					LM3601X_MODE_STROBE, LED_OFF);

		goto out;

	}



	brightness_val = brightness / LM3601X_STROBE_REG_DIV;



	ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);

out:

	mutex_unlock(&led->lock);

	return ret;

}



static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,

				u32 timeout)

{

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);



	mutex_lock(&led->lock);



	led->flash_timeout = timeout;



	mutex_unlock(&led->lock);



	return 0;

}



static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)

{

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

	int strobe_state;

	int ret;



	mutex_lock(&led->lock);



	ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);

	if (ret < 0)

		goto out;



	*state = strobe_state & LM3601X_MODE_STROBE;



out:

	mutex_unlock(&led->lock);

	return ret;

}



static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,

				u32 *fault)

{

	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);



	lm3601x_read_faults(led);



	*fault = led->last_flag;



	return 0;

}



static const struct led_flash_ops flash_ops = {

	.flash_brightness_set	= lm3601x_flash_brightness_set,

	.strobe_set		= lm3601x_strobe_set,

	.strobe_get		= lm3601x_strobe_get,

	.timeout_set		= lm3601x_flash_timeout_set,

	.fault_get		= lm3601x_flash_fault_get,

};



static int lm3601x_register_leds(struct lm3601x_led *led)

{

	struct led_classdev *led_cdev;

	struct led_flash_setting *setting;



	led->fled_cdev.ops = &flash_ops;



	setting = &led->fled_cdev.timeout;

	setting->min = LM3601X_MIN_TIMEOUT_US;

	setting->max = led->max_flash_timeout;

	setting->step = LM3601X_LOWER_STEP_US;

	setting->val = led->max_flash_timeout;



	setting = &led->fled_cdev.brightness;

	setting->min = LM3601X_MIN_STROBE_I_UA;

	setting->max = led->flash_current_max;

	setting->step = LM3601X_TORCH_REG_DIV;

	setting->val = led->flash_current_max;



	led_cdev = &led->fled_cdev.led_cdev;

	led_cdev->name = led->led_name;

	led_cdev->brightness_set_blocking = lm3601x_brightness_set;

	led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,

						LM3601X_TORCH_REG_DIV);

	led_cdev->flags |= LED_DEV_CAP_FLASH;



	return led_classdev_flash_register(&led->client->dev, &led->fled_cdev);

}



static int lm3601x_parse_node(struct lm3601x_led *led)

{

	struct fwnode_handle *child = NULL;

	int ret = -ENODEV;

	const char *name;



	child = device_get_next_child_node(&led->client->dev, child);

	if (!child) {

		dev_err(&led->client->dev, "No LED Child node\n");

		return ret;

	}



	ret = fwnode_property_read_u32(child, "reg", &led->led_mode);

	if (ret) {

		dev_err(&led->client->dev, "reg DT property missing\n");

		goto out_err;

	}



	if (led->led_mode > LM3601X_LED_TORCH ||

	    led->led_mode < LM3601X_LED_IR) {

		dev_warn(&led->client->dev, "Invalid led mode requested\n");

		ret = -EINVAL;

		goto out_err;

	}



	ret = fwnode_property_read_string(child, "label", &name);

	if (ret) {

		if (led->led_mode == LM3601X_LED_TORCH)

			name = "torch";

		else

			name = "infrared";

	}



	snprintf(led->led_name, sizeof(led->led_name),

		"%s:%s", led->client->name, name);



	ret = fwnode_property_read_u32(child, "led-max-microamp",

					&led->torch_current_max);

	if (ret) {

		dev_warn(&led->client->dev,

			"led-max-microamp DT property missing\n");

		goto out_err;

	}



	ret = fwnode_property_read_u32(child, "flash-max-microamp",

				&led->flash_current_max);

	if (ret) {

		dev_warn(&led->client->dev,

			 "flash-max-microamp DT property missing\n");

		goto out_err;

	}



	ret = fwnode_property_read_u32(child, "flash-max-timeout-us",

				&led->max_flash_timeout);

	if (ret) {

		dev_warn(&led->client->dev,

			 "flash-max-timeout-us DT property missing\n");

		goto out_err;

	}



out_err:

	fwnode_handle_put(child);

	return ret;

}



static int lm3601x_probe(struct i2c_client *client)

{

	struct lm3601x_led *led;

	int ret;



	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);

	if (!led)

		return -ENOMEM;



	led->client = client;

	i2c_set_clientdata(client, led);



	ret = lm3601x_parse_node(led);

	if (ret)

		return -ENODEV;



	led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);

	if (IS_ERR(led->regmap)) {

		ret = PTR_ERR(led->regmap);

		dev_err(&client->dev,

			"Failed to allocate register map: %d\n", ret);

		return ret;

	}



	mutex_init(&led->lock);



	return lm3601x_register_leds(led);

}



static int lm3601x_remove(struct i2c_client *client)

{

	struct lm3601x_led *led = i2c_get_clientdata(client);



	led_classdev_flash_unregister(&led->fled_cdev);

	mutex_destroy(&led->lock);



	return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,

			   LM3601X_ENABLE_MASK,

			   LM3601X_MODE_STANDBY);

}



static const struct i2c_device_id lm3601x_id[] = {

	{ "LM36010", CHIP_LM36010 },

	{ "LM36011", CHIP_LM36011 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, lm3601x_id);



static const struct of_device_id of_lm3601x_leds_match[] = {

	{ .compatible = "ti,lm36010", },

	{ .compatible = "ti,lm36011", },

	{ }

};

MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);



static struct i2c_driver lm3601x_i2c_driver = {

	.driver = {

		.name = "lm3601x",

		.of_match_table = of_lm3601x_leds_match,

	},

	.probe_new = lm3601x_probe,

	.remove = lm3601x_remove,

	.id_table = lm3601x_id,

};

module_i2c_driver(lm3601x_i2c_driver);



MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");

MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");

MODULE_LICENSE("GPL v2");

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