Commit 59ea3c9f authored by Nikita Travkin's avatar Nikita Travkin Committed by Pavel Machek
Browse files

leds: add aw2013 driver 



This commit adds support for AWINIC AW2013 3-channel LED driver.
The chip supports 3 PWM channels and is controlled with I2C.

Signed-off-by: default avatarNikita Travkin <nikitos.tr@gmail.com>
Signed-off-by: default avatarPavel Machek <pavel@ucw.cz>
parent 9f6b72e4

drivers/leds/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -103,6 +103,16 @@ config LEDS_AS3645A 
	  controller. V4L2 flash API is provided as well if

	  CONFIG_V4L2_FLASH_API is enabled.



config LEDS_AW2013

	tristate "LED support for Awinic AW2013"

	depends on LEDS_CLASS && I2C && OF

	help

	  This option enables support for the AW2013 3-channel

	  LED driver.



	  To compile this driver as a module, choose M here: the module

	  will be called leds-aw2013.



config LEDS_BCM6328

	tristate "LED Support for Broadcom BCM6328"

	depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ obj-$(CONFIG_LEDS_APU) += leds-apu.o 
obj-$(CONFIG_LEDS_ARIEL)		+= leds-ariel.o

obj-$(CONFIG_LEDS_AS3645A)		+= leds-as3645a.o

obj-$(CONFIG_LEDS_ASIC3)		+= leds-asic3.o

obj-$(CONFIG_LEDS_AW2013)		+= leds-aw2013.o

obj-$(CONFIG_LEDS_BCM6328)		+= leds-bcm6328.o

obj-$(CONFIG_LEDS_BCM6358)		+= leds-bcm6358.o

obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o

drivers/leds/leds-aw2013.c

0 → 100644
+436 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

// Driver for Awinic AW2013 3-channel LED driver



#include <linux/i2c.h>

#include <linux/leds.h>

#include <linux/module.h>

#include <linux/regulator/consumer.h>

#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/regmap.h>



#define AW2013_MAX_LEDS 3



/* Reset and ID register */

#define AW2013_RSTR 0x00

#define AW2013_RSTR_RESET 0x55

#define AW2013_RSTR_CHIP_ID 0x33



/* Global control register */

#define AW2013_GCR 0x01

#define AW2013_GCR_ENABLE BIT(0)



/* LED channel enable register */

#define AW2013_LCTR 0x30

#define AW2013_LCTR_LE(x) BIT((x))



/* LED channel control registers */

#define AW2013_LCFG(x) (0x31 + (x))

#define AW2013_LCFG_IMAX_MASK (BIT(0) | BIT(1)) // Should be 0-3

#define AW2013_LCFG_MD BIT(4)

#define AW2013_LCFG_FI BIT(5)

#define AW2013_LCFG_FO BIT(6)



/* LED channel PWM registers */

#define AW2013_REG_PWM(x) (0x34 + (x))



/* LED channel timing registers */

#define AW2013_LEDT0(x) (0x37 + (x) * 3)

#define AW2013_LEDT0_T1(x) ((x) << 4) // Should be 0-7

#define AW2013_LEDT0_T2(x) (x) // Should be 0-5



#define AW2013_LEDT1(x) (0x38 + (x) * 3)

#define AW2013_LEDT1_T3(x) ((x) << 4) // Should be 0-7

#define AW2013_LEDT1_T4(x) (x) // Should be 0-7



#define AW2013_LEDT2(x) (0x39 + (x) * 3)

#define AW2013_LEDT2_T0(x) ((x) << 4) // Should be 0-8

#define AW2013_LEDT2_REPEAT(x) (x) // Should be 0-15



#define AW2013_REG_MAX 0x77



#define AW2013_TIME_STEP 130 /* ms */



struct aw2013;



struct aw2013_led {

	struct aw2013 *chip;

	struct led_classdev cdev;

	u32 num;

	unsigned int imax;

};



struct aw2013 {

	struct mutex mutex; /* held when writing to registers */

	struct regulator *vcc_regulator;

	struct i2c_client *client;

	struct aw2013_led leds[AW2013_MAX_LEDS];

	struct regmap *regmap;

	int num_leds;

	bool enabled;

};



static int aw2013_chip_init(struct aw2013 *chip)

{

	int i, ret;



	ret = regmap_write(chip->regmap, AW2013_GCR, AW2013_GCR_ENABLE);

	if (ret) {

		dev_err(&chip->client->dev, "Failed to enable the chip: %d\n",

			ret);

		return ret;

	}



	for (i = 0; i < chip->num_leds; i++) {

		ret = regmap_update_bits(chip->regmap,

					 AW2013_LCFG(chip->leds[i].num),

					 AW2013_LCFG_IMAX_MASK,

					 chip->leds[i].imax);

		if (ret) {

			dev_err(&chip->client->dev,

				"Failed to set maximum current for led %d: %d\n",

				chip->leds[i].num, ret);

			return ret;

		}

	}



	return ret;

}



static void aw2013_chip_disable(struct aw2013 *chip)

{

	int ret;



	if (!chip->enabled)

		return;



	regmap_write(chip->regmap, AW2013_GCR, 0);



	ret = regulator_disable(chip->vcc_regulator);

	if (ret) {

		dev_err(&chip->client->dev,

			"Failed to disable regulator: %d\n", ret);

		return;

	}



	chip->enabled = false;

}



static int aw2013_chip_enable(struct aw2013 *chip)

{

	int ret;



	if (chip->enabled)

		return 0;



	ret = regulator_enable(chip->vcc_regulator);

	if (ret) {

		dev_err(&chip->client->dev,

			"Failed to enable regulator: %d\n", ret);

		return ret;

	}

	chip->enabled = true;



	ret = aw2013_chip_init(chip);

	if (ret)

		aw2013_chip_disable(chip);



	return ret;

}



static bool aw2013_chip_in_use(struct aw2013 *chip)

{

	int i;



	for (i = 0; i < chip->num_leds; i++)

		if (chip->leds[i].cdev.brightness)

			return true;



	return false;

}



static int aw2013_brightness_set(struct led_classdev *cdev,

				 enum led_brightness brightness)

{

	struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);

	int ret, num;



	mutex_lock(&led->chip->mutex);



	if (aw2013_chip_in_use(led->chip)) {

		ret = aw2013_chip_enable(led->chip);

		if (ret)

			goto error;

	}



	num = led->num;



	ret = regmap_write(led->chip->regmap, AW2013_REG_PWM(num), brightness);

	if (ret)

		goto error;



	if (brightness) {

		ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,

					 AW2013_LCTR_LE(num), 0xFF);

	} else {

		ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,

					 AW2013_LCTR_LE(num), 0);

		if (ret)

			goto error;

		ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),

					 AW2013_LCFG_MD, 0);

	}

	if (ret)

		goto error;



	if (!aw2013_chip_in_use(led->chip))

		aw2013_chip_disable(led->chip);



error:

	mutex_unlock(&led->chip->mutex);



	return ret;

}



static int aw2013_blink_set(struct led_classdev *cdev,

			    unsigned long *delay_on, unsigned long *delay_off)

{

	struct aw2013_led *led = container_of(cdev, struct aw2013_led, cdev);

	int ret, num = led->num;

	unsigned long off = 0, on = 0;



	/* If no blink specified, default to 1 Hz. */

	if (!*delay_off && !*delay_on) {

		*delay_off = 500;

		*delay_on = 500;

	}



	if (!led->cdev.brightness) {

		led->cdev.brightness = LED_FULL;

		ret = aw2013_brightness_set(&led->cdev, led->cdev.brightness);

		if (ret)

			return ret;

	}



	/* Never on - just set to off */

	if (!*delay_on) {

		led->cdev.brightness = LED_OFF;

		return aw2013_brightness_set(&led->cdev, LED_OFF);

	}



	mutex_lock(&led->chip->mutex);



	/* Never off - brightness is already set, disable blinking */

	if (!*delay_off) {

		ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),

					 AW2013_LCFG_MD, 0);

		goto out;

	}



	/* Convert into values the HW will understand. */

	off = min(5, ilog2((*delay_off - 1) / AW2013_TIME_STEP) + 1);

	on = min(7, ilog2((*delay_on - 1) / AW2013_TIME_STEP) + 1);



	*delay_off = BIT(off) * AW2013_TIME_STEP;

	*delay_on = BIT(on) * AW2013_TIME_STEP;



	/* Set timings */

	ret = regmap_write(led->chip->regmap,

			   AW2013_LEDT0(num), AW2013_LEDT0_T2(on));

	if (ret)

		goto out;

	ret = regmap_write(led->chip->regmap,

			   AW2013_LEDT1(num), AW2013_LEDT1_T4(off));

	if (ret)

		goto out;



	/* Finally, enable the LED */

	ret = regmap_update_bits(led->chip->regmap, AW2013_LCFG(num),

				 AW2013_LCFG_MD, 0xFF);

	if (ret)

		goto out;



	ret = regmap_update_bits(led->chip->regmap, AW2013_LCTR,

				 AW2013_LCTR_LE(num), 0xFF);



out:

	mutex_unlock(&led->chip->mutex);



	return ret;

}



static int aw2013_probe_dt(struct aw2013 *chip)

{

	struct device_node *np = chip->client->dev.of_node, *child;

	int count, ret = 0, i = 0;

	struct aw2013_led *led;



	count = of_get_child_count(np);

	if (!count || count > AW2013_MAX_LEDS)

		return -EINVAL;



	regmap_write(chip->regmap, AW2013_RSTR, AW2013_RSTR_RESET);



	for_each_available_child_of_node(np, child) {

		struct led_init_data init_data = {};

		u32 source;

		u32 imax;



		ret = of_property_read_u32(child, "reg", &source);

		if (ret != 0 || source >= AW2013_MAX_LEDS) {

			dev_err(&chip->client->dev,

				"Couldn't read LED address: %d\n", ret);

			count--;

			continue;

		}



		led = &chip->leds[i];

		led->num = source;

		led->chip = chip;

		init_data.fwnode = of_fwnode_handle(child);



		if (!of_property_read_u32(child, "led-max-microamp", &imax)) {

			led->imax = min_t(u32, imax / 5000, 3);

		} else {

			led->imax = 1; // 5mA

			dev_info(&chip->client->dev,

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

		}



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

					&led->cdev.default_trigger);



		led->cdev.brightness_set_blocking = aw2013_brightness_set;

		led->cdev.blink_set = aw2013_blink_set;



		ret = devm_led_classdev_register_ext(&chip->client->dev,

						     &led->cdev, &init_data);

		if (ret < 0)

			return ret;



		i++;

	}



	if (!count)

		return -EINVAL;



	chip->num_leds = i;



	return 0;

}



static const struct regmap_config aw2013_regmap_config = {

	.reg_bits = 8,

	.val_bits = 8,

	.max_register = AW2013_REG_MAX,

};



static int aw2013_probe(struct i2c_client *client)

{

	struct aw2013 *chip;

	int ret;

	unsigned int chipid;



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

	if (!chip)

		return -ENOMEM;



	mutex_init(&chip->mutex);

	mutex_lock(&chip->mutex);



	chip->client = client;

	i2c_set_clientdata(client, chip);



	chip->regmap = devm_regmap_init_i2c(client, &aw2013_regmap_config);

	if (IS_ERR(chip->regmap)) {

		ret = PTR_ERR(chip->regmap);

		dev_err(&client->dev, "Failed to allocate register map: %d\n",

			ret);

		goto error;

	}



	chip->vcc_regulator = devm_regulator_get(&client->dev, "vcc");

	ret = PTR_ERR_OR_ZERO(chip->vcc_regulator);

	if (ret) {

		if (ret != -EPROBE_DEFER)

			dev_err(&client->dev,

				"Failed to request regulator: %d\n", ret);

		goto error;

	}



	ret = regulator_enable(chip->vcc_regulator);

	if (ret) {

		dev_err(&client->dev,

			"Failed to enable regulator: %d\n", ret);

		goto error;

	}



	ret = regmap_read(chip->regmap, AW2013_RSTR, &chipid);

	if (ret) {

		dev_err(&client->dev, "Failed to read chip ID: %d\n",

			ret);

		goto error_reg;

	}



	if (chipid != AW2013_RSTR_CHIP_ID) {

		dev_err(&client->dev, "Chip reported wrong ID: %x\n",

			chipid);

		ret = -ENODEV;

		goto error_reg;

	}



	ret = aw2013_probe_dt(chip);

	if (ret < 0)

		goto error_reg;



	ret = regulator_disable(chip->vcc_regulator);

	if (ret) {

		dev_err(&client->dev,

			"Failed to disable regulator: %d\n", ret);

		goto error;

	}



	mutex_unlock(&chip->mutex);



	return 0;



error_reg:

	regulator_disable(chip->vcc_regulator);



error:

	mutex_destroy(&chip->mutex);

	return ret;

}



static int aw2013_remove(struct i2c_client *client)

{

	struct aw2013 *chip = i2c_get_clientdata(client);



	aw2013_chip_disable(chip);



	mutex_destroy(&chip->mutex);



	return 0;

}



static const struct of_device_id aw2013_match_table[] = {

	{ .compatible = "awinic,aw2013", },

	{ /* sentinel */ },

};



MODULE_DEVICE_TABLE(of, aw2013_match_table);



static struct i2c_driver aw2013_driver = {

	.driver = {

		.name = "leds-aw2013",

		.of_match_table = of_match_ptr(aw2013_match_table),

	},

	.probe_new = aw2013_probe,

	.remove = aw2013_remove,

};



module_i2c_driver(aw2013_driver);



MODULE_AUTHOR("Nikita Travkin <nikitos.tr@gmail.com>");

MODULE_DESCRIPTION("AW2013 LED driver");

MODULE_LICENSE("GPL v2");