Commit cef8ec8c authored by Luca Weiss's avatar Luca Weiss Committed by Pavel Machek
Browse files

leds: add sgm3140 driver 



Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.

This device is controlled by two GPIO pins, one for enabling and the
second one for switching between torch and flash mode.

Signed-off-by: default avatarLuca Weiss <luca@z3ntu.xyz>
Signed-off-by: default avatarPavel Machek <pavel@ucw.cz>
parent ea4407fa

drivers/leds/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -868,6 +868,14 @@ config LEDS_IP30 
	  To compile this driver as a module, choose M here: the module

	  will be called leds-ip30.



config LEDS_SGM3140

	tristate "LED support for the SGM3140"

	depends on LEDS_CLASS_FLASH

	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS

	help

	  This option enables support for the SGM3140 500mA Buck/Boost Charge

	  Pump LED Driver.



comment "LED Triggers"

source "drivers/leds/trigger/Kconfig"

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ obj-$(CONFIG_LEDS_PWM) += leds-pwm.o 
obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o

obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o

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

obj-$(CONFIG_LEDS_SGM3140)		+= leds-sgm3140.o

obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o

obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o

obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o

drivers/leds/leds-sgm3140.c

0 → 100644
+320 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2020 Luca Weiss <luca@z3ntu.xyz>



#include <linux/gpio/consumer.h>

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

#include <linux/module.h>

#include <linux/regulator/consumer.h>

#include <linux/platform_device.h>



#include <media/v4l2-flash-led-class.h>



#define FLASH_TIMEOUT_DEFAULT		250000U /* 250ms */

#define FLASH_MAX_TIMEOUT_DEFAULT	300000U /* 300ms */



struct sgm3140 {

	struct led_classdev_flash fled_cdev;

	struct v4l2_flash *v4l2_flash;



	struct timer_list powerdown_timer;



	struct gpio_desc *flash_gpio;

	struct gpio_desc *enable_gpio;

	struct regulator *vin_regulator;



	bool enabled;



	/* current timeout in us */

	u32 timeout;

	/* maximum timeout in us */

	u32 max_timeout;

};



static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)

{

	return container_of(flcdev, struct sgm3140, fled_cdev);

}



static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)

{

	struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);

	int ret;



	if (priv->enabled == state)

		return 0;



	if (state) {

		ret = regulator_enable(priv->vin_regulator);

		if (ret) {

			dev_err(fled_cdev->led_cdev.dev,

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

			return ret;

		}

		gpiod_set_value_cansleep(priv->flash_gpio, 1);

		gpiod_set_value_cansleep(priv->enable_gpio, 1);

		mod_timer(&priv->powerdown_timer,

			  jiffies + usecs_to_jiffies(priv->timeout));

	} else {

		del_timer_sync(&priv->powerdown_timer);

		gpiod_set_value_cansleep(priv->enable_gpio, 0);

		gpiod_set_value_cansleep(priv->flash_gpio, 0);

		ret = regulator_disable(priv->vin_regulator);

		if (ret) {

			dev_err(fled_cdev->led_cdev.dev,

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

			return ret;

		}

	}



	priv->enabled = state;



	return 0;

}



static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)

{

	struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);



	*state = timer_pending(&priv->powerdown_timer);



	return 0;

}



static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,

			       u32 timeout)

{

	struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);



	priv->timeout = timeout;



	return 0;

}



static const struct led_flash_ops sgm3140_flash_ops = {

	.strobe_set = sgm3140_strobe_set,

	.strobe_get = sgm3140_strobe_get,

	.timeout_set = sgm3140_timeout_set,

};



static int sgm3140_brightness_set(struct led_classdev *led_cdev,

				  enum led_brightness brightness)

{

	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

	struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);

	bool enable = brightness == LED_ON;

	int ret;



	if (priv->enabled == enable)

		return 0;



	if (enable) {

		ret = regulator_enable(priv->vin_regulator);

		if (ret) {

			dev_err(led_cdev->dev,

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

			return ret;

		}

		gpiod_set_value_cansleep(priv->enable_gpio, 1);

	} else {

		gpiod_set_value_cansleep(priv->enable_gpio, 0);

		ret = regulator_disable(priv->vin_regulator);

		if (ret) {

			dev_err(led_cdev->dev,

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

			return ret;

		}

	}



	priv->enabled = enable;



	return 0;

}



static void sgm3140_powerdown_timer(struct timer_list *t)

{

	struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);



	gpiod_set_value(priv->enable_gpio, 0);

	gpiod_set_value(priv->flash_gpio, 0);

	regulator_disable(priv->vin_regulator);



	priv->enabled = false;

}



static void sgm3140_init_flash_timeout(struct sgm3140 *priv)

{

	struct led_classdev_flash *fled_cdev = &priv->fled_cdev;

	struct led_flash_setting *s;



	/* Init flash timeout setting */

	s = &fled_cdev->timeout;

	s->min = 1;

	s->max = priv->max_timeout;

	s->step = 1;

	s->val = FLASH_TIMEOUT_DEFAULT;

}



#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)

static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,

					struct v4l2_flash_config *v4l2_sd_cfg)

{

	struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;

	struct led_flash_setting *s;



	strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,

		sizeof(v4l2_sd_cfg->dev_name));



	/* Init flash intensity setting */

	s = &v4l2_sd_cfg->intensity;

	s->min = 0;

	s->max = 1;

	s->step = 1;

	s->val = 1;

}



#else

static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,

					struct v4l2_flash_config *v4l2_sd_cfg)

{

}

#endif



static int sgm3140_probe(struct platform_device *pdev)

{

	struct sgm3140 *priv;

	struct led_classdev *led_cdev;

	struct led_classdev_flash *fled_cdev;

	struct led_init_data init_data = {};

	struct fwnode_handle *child_node;

	struct v4l2_flash_config v4l2_sd_cfg = {};

	int ret;



	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);

	ret = PTR_ERR_OR_ZERO(priv->flash_gpio);

	if (ret) {

		if (ret != -EPROBE_DEFER)

			dev_err(&pdev->dev,

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

		return ret;

	}



	priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);

	ret = PTR_ERR_OR_ZERO(priv->enable_gpio);

	if (ret) {

		if (ret != -EPROBE_DEFER)

			dev_err(&pdev->dev,

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

		return ret;

	}



	priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");

	ret = PTR_ERR_OR_ZERO(priv->vin_regulator);

	if (ret) {

		if (ret != -EPROBE_DEFER)

			dev_err(&pdev->dev,

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

		return ret;

	}



	child_node = fwnode_get_next_available_child_node(pdev->dev.fwnode,

							  NULL);

	if (!child_node) {

		dev_err(&pdev->dev,

			"No fwnode child node found for connected LED.\n");

		return -EINVAL;

	}



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

				       &priv->max_timeout);

	if (ret) {

		priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;

		dev_warn(&pdev->dev,

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

	}



	/*

	 * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout

	 * from DT is lower.

	 */

	priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);



	timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);



	fled_cdev = &priv->fled_cdev;

	led_cdev = &fled_cdev->led_cdev;



	fled_cdev->ops = &sgm3140_flash_ops;



	led_cdev->brightness_set_blocking = sgm3140_brightness_set;

	led_cdev->max_brightness = LED_ON;

	led_cdev->flags |= LED_DEV_CAP_FLASH;



	sgm3140_init_flash_timeout(priv);



	init_data.fwnode = child_node;



	platform_set_drvdata(pdev, priv);



	/* Register in the LED subsystem */

	ret = devm_led_classdev_flash_register_ext(&pdev->dev,

						   fled_cdev, &init_data);

	if (ret) {

		dev_err(&pdev->dev, "Failed to register flash device: %d\n",

			ret);

		goto err;

	}



	sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);



	/* Create V4L2 Flash subdev */

	priv->v4l2_flash = v4l2_flash_init(&pdev->dev,

					   child_node,

					   fled_cdev, NULL,

					   &v4l2_sd_cfg);

	if (IS_ERR(priv->v4l2_flash)) {

		ret = PTR_ERR(priv->v4l2_flash);

		goto err;

	}



	return ret;



err:

	fwnode_handle_put(child_node);

	return ret;

}



static int sgm3140_remove(struct platform_device *pdev)

{

	struct sgm3140 *priv = platform_get_drvdata(pdev);



	del_timer_sync(&priv->powerdown_timer);



	v4l2_flash_release(priv->v4l2_flash);



	return 0;

}



static const struct of_device_id sgm3140_dt_match[] = {

	{ .compatible = "sgmicro,sgm3140" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, sgm3140_dt_match);



static struct platform_driver sgm3140_driver = {

	.probe	= sgm3140_probe,

	.remove	= sgm3140_remove,

	.driver	= {

		.name	= "sgm3140",

		.of_match_table = sgm3140_dt_match,

	},

};



module_platform_driver(sgm3140_driver);



MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");

MODULE_DESCRIPTION("SG Micro SGM3140 charge pump led driver");

MODULE_LICENSE("GPL v2");