leds: Add ktd2692 flash LED driver (b7da8c5c) · Commits · 戴 / test

drivers/leds/Kconfig

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		@@ -532,6 +532,15 @@ config LEDS_MENF21BMC
		This driver can also be built as a module. If so the module
		will be called leds-menf21bmc.

		config LEDS_KTD2692
		tristate "LED support for KTD2692 flash LED controller"
		depends on LEDS_CLASS_FLASH && GPIOLIB && OF
		help
		This option enables support for KTD2692 LED flash connected
		through ExpressWire interface.

		Say Y to enable this driver.

		comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"

		config LEDS_BLINKM

drivers/leds/Makefile

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		@@ -63,6 +63,7 @@ obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
		obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o
		obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
		obj-$(CONFIG_LEDS_PM8941_WLED) += leds-pm8941-wled.o
		obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o

		# LED SPI Drivers
		obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o

drivers/leds/leds-ktd2692.c

0 → 100644

+443 −0

Original line number	Diff line number	Diff line
		/*
		* LED driver : leds-ktd2692.c
		*
		* Copyright (C) 2015 Samsung Electronics
		* Ingi Kim <ingi2.kim@samsung.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.
		*/

		#include <linux/delay.h>
		#include <linux/err.h>
		#include <linux/gpio/consumer.h>
		#include <linux/led-class-flash.h>
		#include <linux/module.h>
		#include <linux/mutex.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/regulator/consumer.h>
		#include <linux/workqueue.h>

		/* Value related the movie mode */
		#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
		#define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
		#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE 8

		/* Value related the flash mode */
		#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
		#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
		#define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)

		/* Macro for getting offset of flash timeout */
		#define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))

		/* Base register address */
		#define KTD2692_REG_LVP_BASE 0x00
		#define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
		#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
		#define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
		#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
		#define KTD2692_REG_MODE_BASE 0xA0

		/* Set bit coding time for expresswire interface */
		#define KTD2692_TIME_RESET_US 700
		#define KTD2692_TIME_DATA_START_TIME_US 10
		#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
		#define KTD2692_TIME_LOW_END_OF_DATA_US 10
		#define KTD2692_TIME_SHORT_BITSET_US 4
		#define KTD2692_TIME_LONG_BITSET_US 12

		/* KTD2692 default length of name */
		#define KTD2692_NAME_LENGTH 20

		enum ktd2692_bitset {
		KTD2692_LOW = 0,
		KTD2692_HIGH,
		};

		/* Movie / Flash Mode Control */
		enum ktd2692_led_mode {
		KTD2692_MODE_DISABLE = 0, /* default */
		KTD2692_MODE_MOVIE,
		KTD2692_MODE_FLASH,
		};

		struct ktd2692_led_config_data {
		/* maximum LED current in movie mode */
		u32 movie_max_microamp;
		/* maximum LED current in flash mode */
		u32 flash_max_microamp;
		/* maximum flash timeout */
		u32 flash_max_timeout;
		/* max LED brightness level */
		enum led_brightness max_brightness;
		};

		struct ktd2692_context {
		/* Related LED Flash class device */
		struct led_classdev_flash fled_cdev;

		/* secures access to the device */
		struct mutex lock;
		struct regulator *regulator;
		struct work_struct work_brightness_set;

		struct gpio_desc *aux_gpio;
		struct gpio_desc *ctrl_gpio;

		enum ktd2692_led_mode mode;
		enum led_brightness torch_brightness;
		};

		static struct ktd2692_context *fled_cdev_to_led(
		struct led_classdev_flash *fled_cdev)
		{
		return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
		}

		static void ktd2692_expresswire_start(struct ktd2692_context *led)
		{
		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
		udelay(KTD2692_TIME_DATA_START_TIME_US);
		}

		static void ktd2692_expresswire_reset(struct ktd2692_context *led)
		{
		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
		udelay(KTD2692_TIME_RESET_US);
		}

		static void ktd2692_expresswire_end(struct ktd2692_context *led)
		{
		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
		udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
		udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
		}

		static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
		{
		/*
		* The Low Bit(0) and High Bit(1) is based on a time detection
		* algorithm between time low and time high
		* Time_(L_LB) : Low time of the Low Bit(0)
		* Time_(H_LB) : High time of the LOW Bit(0)
		* Time_(L_HB) : Low time of the High Bit(1)
		* Time_(H_HB) : High time of the High Bit(1)
		*
		* It can be simplified to:
		* Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
		* High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
		* HIGH ___ ____ _.. _________ ___
		* \|_________\| \|_.. \|____\| \|__\|
		* LOW <L_LB> <H_LB> <L_HB> <H_HB>
		* [ Low Bit (0) ] [ High Bit(1) ]
		*/
		if (bit) {
		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
		udelay(KTD2692_TIME_SHORT_BITSET_US);
		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
		udelay(KTD2692_TIME_LONG_BITSET_US);
		} else {
		gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
		udelay(KTD2692_TIME_LONG_BITSET_US);
		gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
		udelay(KTD2692_TIME_SHORT_BITSET_US);
		}
		}

		static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
		{
		int i;

		ktd2692_expresswire_start(led);
		for (i = 7; i >= 0; i--)
		ktd2692_expresswire_set_bit(led, value & BIT(i));
		ktd2692_expresswire_end(led);
		}

		static void ktd2692_brightness_set(struct ktd2692_context *led,
		enum led_brightness brightness)
		{
		mutex_lock(&led->lock);

		if (brightness == LED_OFF) {
		led->mode = KTD2692_MODE_DISABLE;
		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
		} else {
		ktd2692_expresswire_write(led, brightness \|
		KTD2692_REG_MOVIE_CURRENT_BASE);
		led->mode = KTD2692_MODE_MOVIE;
		}

		ktd2692_expresswire_write(led, led->mode \| KTD2692_REG_MODE_BASE);
		mutex_unlock(&led->lock);
		}

		static void ktd2692_brightness_set_work(struct work_struct *work)
		{
		struct ktd2692_context *led =
		container_of(work, struct ktd2692_context, work_brightness_set);

		ktd2692_brightness_set(led, led->torch_brightness);
		}

		static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
		enum led_brightness brightness)
		{
		struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
		struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);

		led->torch_brightness = brightness;
		schedule_work(&led->work_brightness_set);
		}

		static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
		enum led_brightness brightness)
		{
		struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
		struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);

		ktd2692_brightness_set(led, brightness);

		return 0;
		}

		static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
		bool state)
		{
		struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
		struct led_flash_setting *timeout = &fled_cdev->timeout;
		u32 flash_tm_reg;

		mutex_lock(&led->lock);

		if (state) {
		flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
		ktd2692_expresswire_write(led, flash_tm_reg
		\| KTD2692_REG_FLASH_TIMEOUT_BASE);

		led->mode = KTD2692_MODE_FLASH;
		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
		} else {
		led->mode = KTD2692_MODE_DISABLE;
		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
		}

		ktd2692_expresswire_write(led, led->mode \| KTD2692_REG_MODE_BASE);

		fled_cdev->led_cdev.brightness = LED_OFF;
		led->mode = KTD2692_MODE_DISABLE;

		mutex_unlock(&led->lock);

		return 0;
		}

		static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
		u32 timeout)
		{
		return 0;
		}

		static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
		{
		u32 offset, step;
		u32 movie_current_microamp;

		offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
		step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
		/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;

		do {
		movie_current_microamp = step * offset;
		offset--;
		} while ((movie_current_microamp > cfg->movie_max_microamp) &&
		(offset > 0));

		cfg->max_brightness = offset;
		}

		static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
		struct ktd2692_led_config_data *cfg)
		{
		struct led_flash_setting *setting;

		setting = &fled_cdev->timeout;
		setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
		setting->max = cfg->flash_max_timeout;
		setting->step = cfg->flash_max_timeout
		/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
		setting->val = cfg->flash_max_timeout;
		}

		static void ktd2692_setup(struct ktd2692_context *led)
		{
		led->mode = KTD2692_MODE_DISABLE;
		ktd2692_expresswire_reset(led);
		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

		ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
		\| KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
		ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
		\| KTD2692_REG_FLASH_CURRENT_BASE);
		}

		static int ktd2692_parse_dt(struct ktd2692_context led, struct device dev,
		struct ktd2692_led_config_data *cfg)
		{
		struct device_node *np = dev->of_node;
		struct device_node *child_node;
		int ret;

		if (!dev->of_node)
		return -ENXIO;

		led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
		if (IS_ERR(led->ctrl_gpio)) {
		ret = PTR_ERR(led->ctrl_gpio);
		dev_err(dev, "cannot get ctrl-gpios %d\n", ret);
		return ret;
		}

		led->aux_gpio = devm_gpiod_get(dev, "aux");
		if (IS_ERR(led->aux_gpio)) {
		ret = PTR_ERR(led->aux_gpio);
		dev_err(dev, "cannot get aux-gpios %d\n", ret);
		return ret;
		}

		led->regulator = devm_regulator_get(dev, "vin");
		if (IS_ERR(led->regulator))
		led->regulator = NULL;

		if (led->regulator) {
		ret = regulator_enable(led->regulator);
		if (ret)
		dev_err(dev, "Failed to enable supply: %d\n", ret);
		}

		child_node = of_get_next_available_child(np, NULL);
		if (!child_node) {
		dev_err(dev, "No DT child node found for connected LED.\n");
		return -EINVAL;
		}

		led->fled_cdev.led_cdev.name =
		of_get_property(child_node, "label", NULL) ? : child_node->name;

		ret = of_property_read_u32(child_node, "led-max-microamp",
		&cfg->movie_max_microamp);
		if (ret) {
		dev_err(dev, "failed to parse led-max-microamp\n");
		return ret;
		}

		ret = of_property_read_u32(child_node, "flash-max-microamp",
		&cfg->flash_max_microamp);
		if (ret) {
		dev_err(dev, "failed to parse flash-max-microamp\n");
		return ret;
		}

		ret = of_property_read_u32(child_node, "flash-max-timeout-us",
		&cfg->flash_max_timeout);
		if (ret)
		dev_err(dev, "failed to parse flash-max-timeout-us\n");

		of_node_put(child_node);
		return ret;
		}

		static const struct led_flash_ops flash_ops = {
		.strobe_set = ktd2692_led_flash_strobe_set,
		.timeout_set = ktd2692_led_flash_timeout_set,
		};

		static int ktd2692_probe(struct platform_device *pdev)
		{
		struct ktd2692_context *led;
		struct led_classdev *led_cdev;
		struct led_classdev_flash *fled_cdev;
		struct ktd2692_led_config_data led_cfg;
		int ret;

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

		fled_cdev = &led->fled_cdev;
		led_cdev = &fled_cdev->led_cdev;

		ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
		if (ret)
		return ret;

		ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
		ktd2692_init_movie_current_max(&led_cfg);

		fled_cdev->ops = &flash_ops;

		led_cdev->max_brightness = led_cfg.max_brightness;
		led_cdev->brightness_set = ktd2692_led_brightness_set;
		led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
		led_cdev->flags \|= LED_CORE_SUSPENDRESUME \| LED_DEV_CAP_FLASH;

		mutex_init(&led->lock);
		INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);

		platform_set_drvdata(pdev, led);

		ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
		if (ret) {
		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
		mutex_destroy(&led->lock);
		return ret;
		}

		ktd2692_setup(led);

		return 0;
		}

		static int ktd2692_remove(struct platform_device *pdev)
		{
		struct ktd2692_context *led = platform_get_drvdata(pdev);
		int ret;

		led_classdev_flash_unregister(&led->fled_cdev);
		cancel_work_sync(&led->work_brightness_set);

		if (led->regulator) {
		ret = regulator_disable(led->regulator);
		if (ret)
		dev_err(&pdev->dev,
		"Failed to disable supply: %d\n", ret);
		}

		mutex_destroy(&led->lock);

		return 0;
		}

		static const struct of_device_id ktd2692_match[] = {
		{ .compatible = "kinetic,ktd2692", },
		{ /* sentinel */ },
		};

		static struct platform_driver ktd2692_driver = {
		.driver = {
		.name = "ktd2692",
		.of_match_table = ktd2692_match,
		},
		.probe = ktd2692_probe,
		.remove = ktd2692_remove,
		};

		module_platform_driver(ktd2692_driver);

		MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
		MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
		MODULE_LICENSE("GPL v2");

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