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Commit 5c1d824c authored by Dan Murphy's avatar Dan Murphy Committed by Jacek Anaszewski
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leds: lm3697: Introduce the lm3697 driver 

Introduce the lm3697 LED driver for backlighting and display.

Datasheet location:
http://www.ti.com/lit/ds/symlink/lm3697.pdf



Signed-off-by: default avatarDan Murphy <dmurphy@ti.com>
Signed-off-by: default avatarJacek Anaszewski <jacek.anaszewski@gmail.com>
parent b86b9ba5

drivers/leds/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -792,6 +792,14 @@ config LEDS_TI_LMU_COMMON 
	  This supports common features between the TI LM3532, LM3631, LM3632,

	  LM3633, LM3695 and LM3697.



config LEDS_LM3697

	tristate "LED driver for LM3697"

	depends on LEDS_TI_LMU_COMMON

	depends on I2C && OF

	help

	  Say Y to enable the LM3697 LED driver for TI LMU devices.

	  This supports the LED device LM3697.



comment "LED Triggers"

source "drivers/leds/trigger/Kconfig"

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o 
obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o

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

obj-$(CONFIG_LEDS_TI_LMU_COMMON)	+= leds-ti-lmu-common.o

obj-$(CONFIG_LEDS_LM3697)		+= leds-lm3697.o



# LED SPI Drivers

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

drivers/leds/leds-lm3697.c

0 → 100644
+395 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// TI LM3697 LED chip family driver

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



#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/regulator/consumer.h>

#include <linux/leds-ti-lmu-common.h>



#define LM3697_REV			0x0

#define LM3697_RESET			0x1

#define LM3697_OUTPUT_CONFIG		0x10

#define LM3697_CTRL_A_RAMP		0x11

#define LM3697_CTRL_B_RAMP		0x12

#define LM3697_CTRL_A_B_RT_RAMP		0x13

#define LM3697_CTRL_A_B_RAMP_CFG	0x14

#define LM3697_CTRL_A_B_BRT_CFG		0x16

#define LM3697_CTRL_A_FS_CURR_CFG	0x17

#define LM3697_CTRL_B_FS_CURR_CFG	0x18

#define LM3697_PWM_CFG			0x1c

#define LM3697_CTRL_A_BRT_LSB		0x20

#define LM3697_CTRL_A_BRT_MSB		0x21

#define LM3697_CTRL_B_BRT_LSB		0x22

#define LM3697_CTRL_B_BRT_MSB		0x23

#define LM3697_CTRL_ENABLE		0x24



#define LM3697_SW_RESET		BIT(0)



#define LM3697_CTRL_A_EN	BIT(0)

#define LM3697_CTRL_B_EN	BIT(1)

#define LM3697_CTRL_A_B_EN	(LM3697_CTRL_A_EN | LM3697_CTRL_B_EN)



#define LM3697_MAX_LED_STRINGS	3



#define LM3697_CONTROL_A	0

#define LM3697_CONTROL_B	1

#define LM3697_MAX_CONTROL_BANKS 2



/**

 * struct lm3697_led -

 * @hvled_strings: Array of LED strings associated with a control bank

 * @label: LED label

 * @led_dev: LED class device

 * @priv: Pointer to the device struct

 * @lmu_data: Register and setting values for common code

 * @control_bank: Control bank the LED is associated to. 0 is control bank A

 *		   1 is control bank B

 */

struct lm3697_led {

	u32 hvled_strings[LM3697_MAX_LED_STRINGS];

	char label[LED_MAX_NAME_SIZE];

	struct led_classdev led_dev;

	struct lm3697 *priv;

	struct ti_lmu_bank lmu_data;

	int control_bank;

	int enabled;

	int num_leds;

};



/**

 * struct lm3697 -

 * @enable_gpio: Hardware enable gpio

 * @regulator: LED supply regulator pointer

 * @client: Pointer to the I2C client

 * @regmap: Devices register map

 * @dev: Pointer to the devices device struct

 * @lock: Lock for reading/writing the device

 * @leds: Array of LED strings

 */

struct lm3697 {

	struct gpio_desc *enable_gpio;

	struct regulator *regulator;

	struct i2c_client *client;

	struct regmap *regmap;

	struct device *dev;

	struct mutex lock;



	int bank_cfg;



	struct lm3697_led leds[];

};



static const struct reg_default lm3697_reg_defs[] = {

	{LM3697_OUTPUT_CONFIG, 0x6},

	{LM3697_CTRL_A_RAMP, 0x0},

	{LM3697_CTRL_B_RAMP, 0x0},

	{LM3697_CTRL_A_B_RT_RAMP, 0x0},

	{LM3697_CTRL_A_B_RAMP_CFG, 0x0},

	{LM3697_CTRL_A_B_BRT_CFG, 0x0},

	{LM3697_CTRL_A_FS_CURR_CFG, 0x13},

	{LM3697_CTRL_B_FS_CURR_CFG, 0x13},

	{LM3697_PWM_CFG, 0xc},

	{LM3697_CTRL_A_BRT_LSB, 0x0},

	{LM3697_CTRL_A_BRT_MSB, 0x0},

	{LM3697_CTRL_B_BRT_LSB, 0x0},

	{LM3697_CTRL_B_BRT_MSB, 0x0},

	{LM3697_CTRL_ENABLE, 0x0},

};



static const struct regmap_config lm3697_regmap_config = {

	.reg_bits = 8,

	.val_bits = 8,



	.max_register = LM3697_CTRL_ENABLE,

	.reg_defaults = lm3697_reg_defs,

	.num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),

	.cache_type = REGCACHE_FLAT,

};



static int lm3697_brightness_set(struct led_classdev *led_cdev,

				enum led_brightness brt_val)

{

	struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,

					      led_dev);

	int ctrl_en_val = (1 << led->control_bank);

	int ret;



	mutex_lock(&led->priv->lock);



	if (brt_val == LED_OFF) {

		ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,

					 ctrl_en_val, ~ctrl_en_val);

		if (ret) {

			dev_err(&led->priv->client->dev, "Cannot write ctrl register\n");

			goto brightness_out;

		}



		led->enabled = LED_OFF;

	} else {

		ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);

		if (ret) {

			dev_err(&led->priv->client->dev,

				"Cannot write brightness\n");

			goto brightness_out;

		}



		if (!led->enabled) {

			ret = regmap_update_bits(led->priv->regmap,

						 LM3697_CTRL_ENABLE,

						 ctrl_en_val, ctrl_en_val);

			if (ret) {

				dev_err(&led->priv->client->dev,

					"Cannot enable the device\n");

				goto brightness_out;

			}



			led->enabled = brt_val;

		}

	}



brightness_out:

	mutex_unlock(&led->priv->lock);

	return ret;

}



static int lm3697_init(struct lm3697 *priv)

{

	struct lm3697_led *led;

	int i, ret;



	if (priv->enable_gpio) {

		gpiod_direction_output(priv->enable_gpio, 1);

	} else {

		ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);

		if (ret) {

			dev_err(&priv->client->dev, "Cannot reset the device\n");

			goto out;

		}

	}



	ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);

	if (ret) {

		dev_err(&priv->client->dev, "Cannot write ctrl enable\n");

		goto out;

	}



	ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);

	if (ret)

		dev_err(&priv->client->dev, "Cannot write OUTPUT config\n");



	for (i = 0; i < LM3697_MAX_CONTROL_BANKS; i++) {

		led = &priv->leds[i];

		ret = ti_lmu_common_set_ramp(&led->lmu_data);

		if (ret)

			dev_err(&priv->client->dev, "Setting the ramp rate failed\n");

	}

out:

	return ret;

}



static int lm3697_probe_dt(struct lm3697 *priv)

{

	struct fwnode_handle *child = NULL;

	struct lm3697_led *led;

	const char *name;

	int control_bank;

	size_t i = 0;

	int ret = -EINVAL;

	int j;



	priv->enable_gpio = devm_gpiod_get_optional(&priv->client->dev,

						   "enable", GPIOD_OUT_LOW);

	if (IS_ERR(priv->enable_gpio)) {

		ret = PTR_ERR(priv->enable_gpio);

		dev_err(&priv->client->dev, "Failed to get enable gpio: %d\n",

			ret);

		return ret;

	}



	priv->regulator = devm_regulator_get(&priv->client->dev, "vled");

	if (IS_ERR(priv->regulator))

		priv->regulator = NULL;



	device_for_each_child_node(priv->dev, child) {

		ret = fwnode_property_read_u32(child, "reg", &control_bank);

		if (ret) {

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

			fwnode_handle_put(child);

			goto child_out;

		}



		if (control_bank > LM3697_CONTROL_B) {

			dev_err(&priv->client->dev, "reg property is invalid\n");

			ret = -EINVAL;

			fwnode_handle_put(child);

			goto child_out;

		}



		led = &priv->leds[i];



		ret = ti_lmu_common_get_brt_res(&priv->client->dev,

						child, &led->lmu_data);

		if (ret)

			dev_warn(&priv->client->dev, "brightness resolution property missing\n");



		led->control_bank = control_bank;

		led->lmu_data.regmap = priv->regmap;

		led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +

						 control_bank;

		led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +

						   led->control_bank * 2;

		led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +

						   led->control_bank * 2;



		led->num_leds = fwnode_property_read_u32_array(child,

						       "led-sources",

						       NULL, 0);



		if (led->num_leds > LM3697_MAX_LED_STRINGS) {

			dev_err(&priv->client->dev, "To many LED strings defined\n");

			continue;

		}



		ret = fwnode_property_read_u32_array(child, "led-sources",

						    led->hvled_strings,

						    led->num_leds);

		if (ret) {

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

			fwnode_handle_put(child);

			goto child_out;

		}



		for (j = 0; j < led->num_leds; j++)

			priv->bank_cfg |=

				(led->control_bank << led->hvled_strings[j]);



		ret = ti_lmu_common_get_ramp_params(&priv->client->dev,

						    child, &led->lmu_data);

		if (ret)

			dev_warn(&priv->client->dev, "runtime-ramp properties missing\n");



		fwnode_property_read_string(child, "linux,default-trigger",

					    &led->led_dev.default_trigger);



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

		if (ret)

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

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

		else

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

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



		led->priv = priv;

		led->led_dev.name = led->label;

		led->led_dev.max_brightness = led->lmu_data.max_brightness;

		led->led_dev.brightness_set_blocking = lm3697_brightness_set;



		ret = devm_led_classdev_register(priv->dev, &led->led_dev);

		if (ret) {

			dev_err(&priv->client->dev, "led register err: %d\n",

				ret);

			fwnode_handle_put(child);

			goto child_out;

		}



		i++;

	}



child_out:

	return ret;

}



static int lm3697_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct lm3697 *led;

	int count;

	int ret;



	count = device_get_child_node_count(&client->dev);

	if (!count) {

		dev_err(&client->dev, "LEDs are not defined in device tree!");

		return -ENODEV;

	}



	led = devm_kzalloc(&client->dev, struct_size(led, leds, count),

			   GFP_KERNEL);

	if (!led)

		return -ENOMEM;



	mutex_init(&led->lock);

	i2c_set_clientdata(client, led);



	led->client = client;

	led->dev = &client->dev;

	led->regmap = devm_regmap_init_i2c(client, &lm3697_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 = lm3697_probe_dt(led);

	if (ret)

		return ret;



	return lm3697_init(led);

}



static int lm3697_remove(struct i2c_client *client)

{

	struct lm3697 *led = i2c_get_clientdata(client);

	int ret;



	ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,

				 LM3697_CTRL_A_B_EN, 0);

	if (ret) {

		dev_err(&led->client->dev, "Failed to disable the device\n");

		return 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 lm3697_id[] = {

	{ "lm3697", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, lm3697_id);



static const struct of_device_id of_lm3697_leds_match[] = {

	{ .compatible = "ti,lm3697", },

	{},

};

MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);



static struct i2c_driver lm3697_driver = {

	.driver = {

		.name	= "lm3697",

		.of_match_table = of_lm3697_leds_match,

	},

	.probe		= lm3697_probe,

	.remove		= lm3697_remove,

	.id_table	= lm3697_id,

};

module_i2c_driver(lm3697_driver);



MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");

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

MODULE_LICENSE("GPL v2");