[linux-2.6-block.git] / drivers / leds / trigger / ledtrig-gpio.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ledtrig-gio.c - LED Trigger Based on GPIO events
 *
 * Copyright 2009 Felipe Balbi <me@felipebalbi.com>
 * Copyright 2023 Linus Walleij <linus.walleij@linaro.org>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include "../leds.h"

struct gpio_trig_data {
	struct led_classdev *led;
	unsigned desired_brightness;	/* desired brightness when led is on */
	struct gpio_desc *gpiod;	/* gpio that triggers the led */
};

static irqreturn_t gpio_trig_irq(int irq, void *_led)
{
	struct led_classdev *led = _led;
	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
	int tmp;

	tmp = gpiod_get_value_cansleep(gpio_data->gpiod);
	if (tmp) {
		if (gpio_data->desired_brightness)
			led_set_brightness_nosleep(gpio_data->led,
					   gpio_data->desired_brightness);
		else
			led_set_brightness_nosleep(gpio_data->led, LED_FULL);
	} else {
		led_set_brightness_nosleep(gpio_data->led, LED_OFF);
	}

	return IRQ_HANDLED;
}

static ssize_t desired_brightness_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);

	return sysfs_emit(buf, "%u\n", gpio_data->desired_brightness);
}

static ssize_t desired_brightness_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
	u8 desired_brightness;
	int ret;

	ret = kstrtou8(buf, 10, &desired_brightness);
	if (ret)
		return ret;

	gpio_data->desired_brightness = desired_brightness;

	return n;
}
static DEVICE_ATTR_RW(desired_brightness);

static struct attribute *gpio_trig_attrs[] = {
	&dev_attr_desired_brightness.attr,
	NULL
};
ATTRIBUTE_GROUPS(gpio_trig);

static int gpio_trig_activate(struct led_classdev *led)
{
	struct gpio_trig_data *gpio_data;
	struct device *dev = led->dev;
	int ret;

	gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
	if (!gpio_data)
		return -ENOMEM;

	/*
	 * The generic property "trigger-sources" is followed,
	 * and we hope that this is a GPIO.
	 */
	gpio_data->gpiod = gpiod_get_optional(dev, "trigger-sources", GPIOD_IN);
	if (IS_ERR(gpio_data->gpiod)) {
		ret = PTR_ERR(gpio_data->gpiod);
		kfree(gpio_data);
		return ret;
	}
	if (!gpio_data->gpiod) {
		dev_err(dev, "no valid GPIO for the trigger\n");
		kfree(gpio_data);
		return -EINVAL;
	}

	gpiod_set_consumer_name(gpio_data->gpiod, "led-trigger");

	gpio_data->led = led;
	led_set_trigger_data(led, gpio_data);

	ret = request_threaded_irq(gpiod_to_irq(gpio_data->gpiod), NULL, gpio_trig_irq,
			IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
			| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
	if (ret) {
		dev_err(dev, "request_irq failed with error %d\n", ret);
		gpiod_put(gpio_data->gpiod);
		kfree(gpio_data);
		return ret;
	}

	/* Finally update the LED to initial status */
	gpio_trig_irq(0, led);

	return 0;
}

static void gpio_trig_deactivate(struct led_classdev *led)
{
	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);

	free_irq(gpiod_to_irq(gpio_data->gpiod), led);
	gpiod_put(gpio_data->gpiod);
	kfree(gpio_data);
}

static struct led_trigger gpio_led_trigger = {
	.name		= "gpio",
	.activate	= gpio_trig_activate,
	.deactivate	= gpio_trig_deactivate,
	.groups		= gpio_trig_groups,
};
module_led_trigger(gpio_led_trigger);

MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
MODULE_DESCRIPTION("GPIO LED trigger");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* ledtrig-gio.c - LED Trigger Based on GPIO events
	4	*
	5	* Copyright 2009 Felipe Balbi <me@felipebalbi.com>
	6	* Copyright 2023 Linus Walleij <linus.walleij@linaro.org>
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/kernel.h>
	11	#include <linux/init.h>
	12	#include <linux/gpio/consumer.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/leds.h>
	15	#include <linux/slab.h>
	16	#include "../leds.h"
	17
	18	struct gpio_trig_data {
	19	struct led_classdev *led;
	20	unsigned desired_brightness; /* desired brightness when led is on */
	21	struct gpio_desc gpiod; / gpio that triggers the led */
	22	};
	23
	24	static irqreturn_t gpio_trig_irq(int irq, void *_led)
	25	{
	26	struct led_classdev *led = _led;
	27	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
	28	int tmp;
	29
	30	tmp = gpiod_get_value_cansleep(gpio_data->gpiod);
	31	if (tmp) {
	32	if (gpio_data->desired_brightness)
	33	led_set_brightness_nosleep(gpio_data->led,
	34	gpio_data->desired_brightness);
	35	else
	36	led_set_brightness_nosleep(gpio_data->led, LED_FULL);
	37	} else {
	38	led_set_brightness_nosleep(gpio_data->led, LED_OFF);
	39	}
	40
	41	return IRQ_HANDLED;
	42	}
	43
	44	static ssize_t desired_brightness_show(struct device *dev,
	45	struct device_attribute attr, char buf)
	46	{
	47	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
	48
	49	return sysfs_emit(buf, "%u\n", gpio_data->desired_brightness);
	50	}
	51
	52	static ssize_t desired_brightness_store(struct device *dev,
	53	struct device_attribute attr, const char buf, size_t n)
	54	{
	55	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
	56	u8 desired_brightness;
	57	int ret;
	58
	59	ret = kstrtou8(buf, 10, &desired_brightness);
	60	if (ret)
	61	return ret;
	62
	63	gpio_data->desired_brightness = desired_brightness;
	64
	65	return n;
	66	}
	67	static DEVICE_ATTR_RW(desired_brightness);
	68
	69	static struct attribute *gpio_trig_attrs[] = {
	70	&dev_attr_desired_brightness.attr,
	71	NULL
	72	};
	73	ATTRIBUTE_GROUPS(gpio_trig);
	74
	75	static int gpio_trig_activate(struct led_classdev *led)
	76	{
	77	struct gpio_trig_data *gpio_data;
	78	struct device *dev = led->dev;
	79	int ret;
	80
	81	gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
	82	if (!gpio_data)
	83	return -ENOMEM;
	84
	85	/*
	86	* The generic property "trigger-sources" is followed,
	87	* and we hope that this is a GPIO.
	88	*/
	89	gpio_data->gpiod = gpiod_get_optional(dev, "trigger-sources", GPIOD_IN);
	90	if (IS_ERR(gpio_data->gpiod)) {
	91	ret = PTR_ERR(gpio_data->gpiod);
	92	kfree(gpio_data);
	93	return ret;
	94	}
	95	if (!gpio_data->gpiod) {
	96	dev_err(dev, "no valid GPIO for the trigger\n");
	97	kfree(gpio_data);
	98	return -EINVAL;
	99	}
	100
	101	gpiod_set_consumer_name(gpio_data->gpiod, "led-trigger");
	102
	103	gpio_data->led = led;
	104	led_set_trigger_data(led, gpio_data);
	105
	106	ret = request_threaded_irq(gpiod_to_irq(gpio_data->gpiod), NULL, gpio_trig_irq,
	107	IRQF_ONESHOT \| IRQF_SHARED \| IRQF_TRIGGER_RISING
	108	\| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
	109	if (ret) {
	110	dev_err(dev, "request_irq failed with error %d\n", ret);
	111	gpiod_put(gpio_data->gpiod);
	112	kfree(gpio_data);
	113	return ret;
	114	}
	115
	116	/* Finally update the LED to initial status */
	117	gpio_trig_irq(0, led);
	118
	119	return 0;
	120	}
	121
	122	static void gpio_trig_deactivate(struct led_classdev *led)
	123	{
	124	struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
	125
	126	free_irq(gpiod_to_irq(gpio_data->gpiod), led);
	127	gpiod_put(gpio_data->gpiod);
	128	kfree(gpio_data);
	129	}
	130
	131	static struct led_trigger gpio_led_trigger = {
	132	.name = "gpio",
	133	.activate = gpio_trig_activate,
	134	.deactivate = gpio_trig_deactivate,
	135	.groups = gpio_trig_groups,
	136	};
	137	module_led_trigger(gpio_led_trigger);
	138
	139	MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
	140	MODULE_DESCRIPTION("GPIO LED trigger");
	141	MODULE_LICENSE("GPL v2");