[mirror_ubuntu-artful-kernel.git] / drivers / leds / ledtrig-gpio.c

/*
 * ledtrig-gio.c - LED Trigger Based on GPIO events
 *
 * Copyright 2009 Felipe Balbi <me@felipebalbi.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/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include "leds.h"

struct gpio_trig_data {
	struct led_classdev *led;
	struct work_struct work;

	unsigned desired_brightness;	/* desired brightness when led is on */
	unsigned inverted;		/* true when gpio is inverted */
	unsigned gpio;			/* gpio that triggers the leds */
};

static irqreturn_t gpio_trig_irq(int irq, void *_led)
{
	struct led_classdev *led = _led;
	struct gpio_trig_data *gpio_data = led->trigger_data;

	/* just schedule_work since gpio_get_value can sleep */
	schedule_work(&gpio_data->work);

	return IRQ_HANDLED;
};

static void gpio_trig_work(struct work_struct *work)
{
	struct gpio_trig_data *gpio_data = container_of(work,
			struct gpio_trig_data, work);
	int tmp;

	if (!gpio_data->gpio)
		return;

	tmp = gpio_get_value(gpio_data->gpio);
	if (gpio_data->inverted)
		tmp = !tmp;

	if (tmp) {
		if (gpio_data->desired_brightness)
			__led_set_brightness(gpio_data->led,
					   gpio_data->desired_brightness);
		else
			__led_set_brightness(gpio_data->led, LED_FULL);
	} else {
		__led_set_brightness(gpio_data->led, LED_OFF);
	}
}

static ssize_t gpio_trig_brightness_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;

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

static ssize_t gpio_trig_brightness_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;
	unsigned desired_brightness;
	int ret;

	ret = sscanf(buf, "%u", &desired_brightness);
	if (ret < 1 || desired_brightness > 255) {
		dev_err(dev, "invalid value\n");
		return -EINVAL;
	}

	gpio_data->desired_brightness = desired_brightness;

	return n;
}
static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
		gpio_trig_brightness_store);

static ssize_t gpio_trig_inverted_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;

	return sprintf(buf, "%u\n", gpio_data->inverted);
}

static ssize_t gpio_trig_inverted_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;
	unsigned long inverted;
	int ret;

	ret = strict_strtoul(buf, 10, &inverted);
	if (ret < 0)
		return ret;

	if (inverted > 1)
		return -EINVAL;

	gpio_data->inverted = inverted;

	/* After inverting, we need to update the LED. */
	schedule_work(&gpio_data->work);

	return n;
}
static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
		gpio_trig_inverted_store);

static ssize_t gpio_trig_gpio_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;

	return sprintf(buf, "%u\n", gpio_data->gpio);
}

static ssize_t gpio_trig_gpio_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	struct led_classdev *led = dev_get_drvdata(dev);
	struct gpio_trig_data *gpio_data = led->trigger_data;
	unsigned gpio;
	int ret;

	ret = sscanf(buf, "%u", &gpio);
	if (ret < 1) {
		dev_err(dev, "couldn't read gpio number\n");
		flush_work(&gpio_data->work);
		return -EINVAL;
	}

	if (gpio_data->gpio == gpio)
		return n;

	if (!gpio) {
		if (gpio_data->gpio != 0)
			free_irq(gpio_to_irq(gpio_data->gpio), led);
		gpio_data->gpio = 0;
		return n;
	}

	ret = request_irq(gpio_to_irq(gpio), gpio_trig_irq,
			IRQF_SHARED | IRQF_TRIGGER_RISING
			| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
	if (ret) {
		dev_err(dev, "request_irq failed with error %d\n", ret);
	} else {
		if (gpio_data->gpio != 0)
			free_irq(gpio_to_irq(gpio_data->gpio), led);
		gpio_data->gpio = gpio;
	}

	return ret ? ret : n;
}
static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);

static void gpio_trig_activate(struct led_classdev *led)
{
	struct gpio_trig_data *gpio_data;
	int ret;

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

	ret = device_create_file(led->dev, &dev_attr_gpio);
	if (ret)
		goto err_gpio;

	ret = device_create_file(led->dev, &dev_attr_inverted);
	if (ret)
		goto err_inverted;

	ret = device_create_file(led->dev, &dev_attr_desired_brightness);
	if (ret)
		goto err_brightness;

	gpio_data->led = led;
	led->trigger_data = gpio_data;
	INIT_WORK(&gpio_data->work, gpio_trig_work);
	led->activated = true;

	return;

err_brightness:
	device_remove_file(led->dev, &dev_attr_inverted);

err_inverted:
	device_remove_file(led->dev, &dev_attr_gpio);

err_gpio:
	kfree(gpio_data);
}

static void gpio_trig_deactivate(struct led_classdev *led)
{
	struct gpio_trig_data *gpio_data = led->trigger_data;

	if (led->activated) {
		device_remove_file(led->dev, &dev_attr_gpio);
		device_remove_file(led->dev, &dev_attr_inverted);
		device_remove_file(led->dev, &dev_attr_desired_brightness);
		flush_work(&gpio_data->work);
		if (gpio_data->gpio != 0)
			free_irq(gpio_to_irq(gpio_data->gpio), led);
		kfree(gpio_data);
		led->activated = false;
	}
}

static struct led_trigger gpio_led_trigger = {
	.name		= "gpio",
	.activate	= gpio_trig_activate,
	.deactivate	= gpio_trig_deactivate,
};

static int __init gpio_trig_init(void)
{
	return led_trigger_register(&gpio_led_trigger);
}
module_init(gpio_trig_init);

static void __exit gpio_trig_exit(void)
{
	led_trigger_unregister(&gpio_led_trigger);
}
module_exit(gpio_trig_exit);

MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
MODULE_DESCRIPTION("GPIO LED trigger");
MODULE_LICENSE("GPL");
Commit	Line	Data
17354bfe FB	1	/*
	2	* ledtrig-gio.c - LED Trigger Based on GPIO events
	3	*
	4	* Copyright 2009 Felipe Balbi <me@felipebalbi.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/init.h>
	15	#include <linux/gpio.h>
	16	#include <linux/interrupt.h>
	17	#include <linux/workqueue.h>
	18	#include <linux/leds.h>
5a0e3ad6	19	#include <linux/slab.h>
17354bfe FB	20	#include "leds.h"
	21
	22	struct gpio_trig_data {
	23	struct led_classdev *led;
	24	struct work_struct work;
	25
	26	unsigned desired_brightness; /* desired brightness when led is on */
	27	unsigned inverted; /* true when gpio is inverted */
	28	unsigned gpio; /* gpio that triggers the leds */
	29	};
	30
	31	static irqreturn_t gpio_trig_irq(int irq, void *_led)
	32	{
	33	struct led_classdev *led = _led;
	34	struct gpio_trig_data *gpio_data = led->trigger_data;
	35
	36	/* just schedule_work since gpio_get_value can sleep */
	37	schedule_work(&gpio_data->work);
	38
	39	return IRQ_HANDLED;
	40	};
	41
	42	static void gpio_trig_work(struct work_struct *work)
	43	{
	44	struct gpio_trig_data *gpio_data = container_of(work,
	45	struct gpio_trig_data, work);
	46	int tmp;
	47
74cbe202 TLSC	48	if (!gpio_data->gpio)
74cbe202 TLSC	49	return;
17354bfe	50
74cbe202 TLSC	51	tmp = gpio_get_value(gpio_data->gpio);
	52	if (gpio_data->inverted)
	53	tmp = !tmp;
17354bfe	54
74cbe202 TLSC	55	if (tmp) {
74cbe202 TLSC	56	if (gpio_data->desired_brightness)
0da3e65b	57	__led_set_brightness(gpio_data->led,
74cbe202 TLSC	58	gpio_data->desired_brightness);
74cbe202 TLSC	59	else
0da3e65b	60	__led_set_brightness(gpio_data->led, LED_FULL);
74cbe202	61	} else {
0da3e65b	62	__led_set_brightness(gpio_data->led, LED_OFF);
74cbe202	63	}
17354bfe FB	64	}
	65
	66	static ssize_t gpio_trig_brightness_show(struct device *dev,
	67	struct device_attribute attr, char buf)
	68	{
	69	struct led_classdev *led = dev_get_drvdata(dev);
	70	struct gpio_trig_data *gpio_data = led->trigger_data;
	71
	72	return sprintf(buf, "%u\n", gpio_data->desired_brightness);
	73	}
	74
	75	static ssize_t gpio_trig_brightness_store(struct device *dev,
	76	struct device_attribute attr, const char buf, size_t n)
	77	{
	78	struct led_classdev *led = dev_get_drvdata(dev);
	79	struct gpio_trig_data *gpio_data = led->trigger_data;
	80	unsigned desired_brightness;
	81	int ret;
	82
	83	ret = sscanf(buf, "%u", &desired_brightness);
	84	if (ret < 1 \|\| desired_brightness > 255) {
	85	dev_err(dev, "invalid value\n");
	86	return -EINVAL;
	87	}
	88
	89	gpio_data->desired_brightness = desired_brightness;
	90
	91	return n;
	92	}
	93	static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
	94	gpio_trig_brightness_store);
	95
	96	static ssize_t gpio_trig_inverted_show(struct device *dev,
	97	struct device_attribute attr, char buf)
	98	{
	99	struct led_classdev *led = dev_get_drvdata(dev);
	100	struct gpio_trig_data *gpio_data = led->trigger_data;
	101
cc587ece	102	return sprintf(buf, "%u\n", gpio_data->inverted);
17354bfe FB	103	}
	104
	105	static ssize_t gpio_trig_inverted_store(struct device *dev,
	106	struct device_attribute attr, const char buf, size_t n)
	107	{
	108	struct led_classdev *led = dev_get_drvdata(dev);
	109	struct gpio_trig_data *gpio_data = led->trigger_data;
cc587ece	110	unsigned long inverted;
17354bfe FB	111	int ret;
17354bfe FB	112
cc587ece JK	113	ret = strict_strtoul(buf, 10, &inverted);
	114	if (ret < 0)
	115	return ret;
	116
	117	if (inverted > 1)
17354bfe	118	return -EINVAL;
17354bfe	119
cc587ece	120	gpio_data->inverted = inverted;
17354bfe	121
cc674c81 TLSC	122	/* After inverting, we need to update the LED. */
	123	schedule_work(&gpio_data->work);
	124
17354bfe FB	125	return n;
	126	}
	127	static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
	128	gpio_trig_inverted_store);
	129
	130	static ssize_t gpio_trig_gpio_show(struct device *dev,
	131	struct device_attribute attr, char buf)
	132	{
	133	struct led_classdev *led = dev_get_drvdata(dev);
	134	struct gpio_trig_data *gpio_data = led->trigger_data;
	135
	136	return sprintf(buf, "%u\n", gpio_data->gpio);
	137	}
	138
	139	static ssize_t gpio_trig_gpio_store(struct device *dev,
	140	struct device_attribute attr, const char buf, size_t n)
	141	{
	142	struct led_classdev *led = dev_get_drvdata(dev);
	143	struct gpio_trig_data *gpio_data = led->trigger_data;
	144	unsigned gpio;
	145	int ret;
	146
	147	ret = sscanf(buf, "%u", &gpio);
	148	if (ret < 1) {
	149	dev_err(dev, "couldn't read gpio number\n");
	150	flush_work(&gpio_data->work);
	151	return -EINVAL;
	152	}
	153
48cccd26 TLSC	154	if (gpio_data->gpio == gpio)
	155	return n;
	156
17354bfe	157	if (!gpio) {
48cccd26 TLSC	158	if (gpio_data->gpio != 0)
	159	free_irq(gpio_to_irq(gpio_data->gpio), led);
	160	gpio_data->gpio = 0;
17354bfe FB	161	return n;
	162	}
	163
17354bfe FB	164	ret = request_irq(gpio_to_irq(gpio), gpio_trig_irq,
	165	IRQF_SHARED \| IRQF_TRIGGER_RISING
	166	\| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
48cccd26	167	if (ret) {
17354bfe	168	dev_err(dev, "request_irq failed with error %d\n", ret);
48cccd26 TLSC	169	} else {
	170	if (gpio_data->gpio != 0)
	171	free_irq(gpio_to_irq(gpio_data->gpio), led);
	172	gpio_data->gpio = gpio;
	173	}
17354bfe FB	174
	175	return ret ? ret : n;
	176	}
	177	static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
	178
	179	static void gpio_trig_activate(struct led_classdev *led)
	180	{
	181	struct gpio_trig_data *gpio_data;
	182	int ret;
	183
	184	gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
	185	if (!gpio_data)
	186	return;
	187
	188	ret = device_create_file(led->dev, &dev_attr_gpio);
	189	if (ret)
	190	goto err_gpio;
	191
	192	ret = device_create_file(led->dev, &dev_attr_inverted);
	193	if (ret)
	194	goto err_inverted;
	195
	196	ret = device_create_file(led->dev, &dev_attr_desired_brightness);
	197	if (ret)
	198	goto err_brightness;
	199
	200	gpio_data->led = led;
	201	led->trigger_data = gpio_data;
	202	INIT_WORK(&gpio_data->work, gpio_trig_work);
03c091e5	203	led->activated = true;
17354bfe FB	204
	205	return;
	206
	207	err_brightness:
	208	device_remove_file(led->dev, &dev_attr_inverted);
	209
	210	err_inverted:
	211	device_remove_file(led->dev, &dev_attr_gpio);
	212
	213	err_gpio:
	214	kfree(gpio_data);
	215	}
	216
	217	static void gpio_trig_deactivate(struct led_classdev *led)
	218	{
	219	struct gpio_trig_data *gpio_data = led->trigger_data;
	220
03c091e5	221	if (led->activated) {
17354bfe FB	222	device_remove_file(led->dev, &dev_attr_gpio);
	223	device_remove_file(led->dev, &dev_attr_inverted);
	224	device_remove_file(led->dev, &dev_attr_desired_brightness);
	225	flush_work(&gpio_data->work);
48cccd26 TLSC	226	if (gpio_data->gpio != 0)
48cccd26 TLSC	227	free_irq(gpio_to_irq(gpio_data->gpio), led);
17354bfe	228	kfree(gpio_data);
03c091e5	229	led->activated = false;
17354bfe FB	230	}
	231	}
	232
	233	static struct led_trigger gpio_led_trigger = {
	234	.name = "gpio",
	235	.activate = gpio_trig_activate,
	236	.deactivate = gpio_trig_deactivate,
	237	};
	238
	239	static int __init gpio_trig_init(void)
	240	{
	241	return led_trigger_register(&gpio_led_trigger);
	242	}
	243	module_init(gpio_trig_init);
	244
	245	static void __exit gpio_trig_exit(void)
	246	{
	247	led_trigger_unregister(&gpio_led_trigger);
	248	}
	249	module_exit(gpio_trig_exit);
	250
	251	MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
	252	MODULE_DESCRIPTION("GPIO LED trigger");
	253	MODULE_LICENSE("GPL");