Initial import

12 files changed, 1591 insertions, 0 deletions

diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
new file mode 100644
index 000000000..49794b47b
--- /dev/null
+++ b/drivers/leds/trigger/Kconfig
@@ -0,0 +1,111 @@
+menuconfig LEDS_TRIGGERS
+	bool "LED Trigger support"
+	depends on LEDS_CLASS
+	help
+	  This option enables trigger support for the leds class.
+	  These triggers allow kernel events to drive the LEDs and can
+	  be configured via sysfs. If unsure, say Y.
+
+if LEDS_TRIGGERS
+
+config LEDS_TRIGGER_TIMER
+	tristate "LED Timer Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by a programmable timer
+	  via sysfs. Some LED hardware can be programmed to start
+	  blinking the LED without any further software interaction.
+	  For more details read Documentation/leds/leds-class.txt.
+
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_ONESHOT
+	tristate "LED One-shot Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to blink in one-shot pulses with parameters
+	  controlled via sysfs.  It's useful to notify the user on
+	  sporadic events, when there are no clear begin and end trap points,
+	  or on dense events, where this blinks the LED at constant rate if
+	  rearmed continuously.
+
+	  It also shows how to use the led_blink_set_oneshot() function.
+
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_IDE_DISK
+	bool "LED IDE Disk Trigger"
+	depends on IDE_GD_ATA
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by IDE disk activity.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_HEARTBEAT
+	tristate "LED Heartbeat Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by a CPU load average.
+	  The flash frequency is a hyperbolic function of the 1-minute
+	  load average.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_BACKLIGHT
+	tristate "LED backlight Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled as a backlight device: they
+	  turn off and on when the display is blanked and unblanked.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_CPU
+	bool "LED CPU Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by active CPUs. This shows
+	  the active CPUs across an array of LEDs so you can see which
+	  CPUs are active on the system at any given moment.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_GPIO
+	tristate "LED GPIO Trigger"
+	depends on LEDS_TRIGGERS
+	depends on GPIOLIB
+	help
+	  This allows LEDs to be controlled by gpio events. It's good
+	  when using gpios as switches and triggering the needed LEDs
+	  from there. One use case is n810's keypad LEDs that could
+	  be triggered by this trigger when user slides up to show
+	  keypad.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_DEFAULT_ON
+	tristate "LED Default ON Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be initialised in the ON state.
+	  If unsure, say Y.
+
+comment "iptables trigger is under Netfilter config (LED target)"
+	depends on LEDS_TRIGGERS
+
+config LEDS_TRIGGER_TRANSIENT
+	tristate "LED Transient Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows one time activation of a transient state on
+	  GPIO/PWM based hardware.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_CAMERA
+	tristate "LED Camera Flash/Torch Trigger"
+	depends on LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled as a camera flash/torch device.
+	  This enables direct flash/torch on/off by the driver, kernel space.
+	  If unsure, say Y.
+
+endif # LEDS_TRIGGERS
diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
new file mode 100644
index 000000000..1abf48dac
--- /dev/null
+++ b/drivers/leds/trigger/Makefile
@@ -0,0 +1,10 @@
+obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o
+obj-$(CONFIG_LEDS_TRIGGER_ONESHOT)	+= ledtrig-oneshot.o
+obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o
+obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)	+= ledtrig-heartbeat.o
+obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT)	+= ledtrig-backlight.o
+obj-$(CONFIG_LEDS_TRIGGER_GPIO)		+= ledtrig-gpio.o
+obj-$(CONFIG_LEDS_TRIGGER_CPU)		+= ledtrig-cpu.o
+obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON)	+= ledtrig-default-on.o
+obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT)	+= ledtrig-transient.o
+obj-$(CONFIG_LEDS_TRIGGER_CAMERA)	+= ledtrig-camera.o
diff --git a/drivers/leds/trigger/ledtrig-backlight.c b/drivers/leds/trigger/ledtrig-backlight.c
new file mode 100644
index 000000000..59eca17d9
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-backlight.c
@@ -0,0 +1,168 @@
+/*
+ * Backlight emulation LED trigger
+ *
+ * Copyright 2008 (C) Rodolfo Giometti <giometti@linux.it>
+ * Copyright 2008 (C) Eurotech S.p.A. <info@eurotech.it>
+ *
+ * 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/slab.h>
+#include <linux/init.h>
+#include <linux/fb.h>
+#include <linux/leds.h>
+#include "../leds.h"
+
+#define BLANK		1
+#define UNBLANK		0
+
+struct bl_trig_notifier {
+	struct led_classdev *led;
+	int brightness;
+	int old_status;
+	struct notifier_block notifier;
+	unsigned invert;
+};
+
+static int fb_notifier_callback(struct notifier_block *p,
+				unsigned long event, void *data)
+{
+	struct bl_trig_notifier *n = container_of(p,
+					struct bl_trig_notifier, notifier);
+	struct led_classdev *led = n->led;
+	struct fb_event *fb_event = data;
+	int *blank;
+	int new_status;
+
+	/* If we aren't interested in this event, skip it immediately ... */
+	if (event != FB_EVENT_BLANK)
+		return 0;
+
+	blank = fb_event->data;
+	new_status = *blank ? BLANK : UNBLANK;
+
+	if (new_status == n->old_status)
+		return 0;
+
+	if ((n->old_status == UNBLANK) ^ n->invert) {
+		n->brightness = led->brightness;
+		led_set_brightness_async(led, LED_OFF);
+	} else {
+		led_set_brightness_async(led, n->brightness);
+	}
+
+	n->old_status = new_status;
+
+	return 0;
+}
+
+static ssize_t bl_trig_invert_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led = dev_get_drvdata(dev);
+	struct bl_trig_notifier *n = led->trigger_data;
+
+	return sprintf(buf, "%u\n", n->invert);
+}
+
+static ssize_t bl_trig_invert_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t num)
+{
+	struct led_classdev *led = dev_get_drvdata(dev);
+	struct bl_trig_notifier *n = led->trigger_data;
+	unsigned long invert;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &invert);
+	if (ret < 0)
+		return ret;
+
+	if (invert > 1)
+		return -EINVAL;
+
+	n->invert = invert;
+
+	/* After inverting, we need to update the LED. */
+	if ((n->old_status == BLANK) ^ n->invert)
+		led_set_brightness_async(led, LED_OFF);
+	else
+		led_set_brightness_async(led, n->brightness);
+
+	return num;
+}
+static DEVICE_ATTR(inverted, 0644, bl_trig_invert_show, bl_trig_invert_store);
+
+static void bl_trig_activate(struct led_classdev *led)
+{
+	int ret;
+
+	struct bl_trig_notifier *n;
+
+	n = kzalloc(sizeof(struct bl_trig_notifier), GFP_KERNEL);
+	led->trigger_data = n;
+	if (!n) {
+		dev_err(led->dev, "unable to allocate backlight trigger\n");
+		return;
+	}
+
+	ret = device_create_file(led->dev, &dev_attr_inverted);
+	if (ret)
+		goto err_invert;
+
+	n->led = led;
+	n->brightness = led->brightness;
+	n->old_status = UNBLANK;
+	n->notifier.notifier_call = fb_notifier_callback;
+
+	ret = fb_register_client(&n->notifier);
+	if (ret)
+		dev_err(led->dev, "unable to register backlight trigger\n");
+	led->activated = true;
+
+	return;
+
+err_invert:
+	led->trigger_data = NULL;
+	kfree(n);
+}
+
+static void bl_trig_deactivate(struct led_classdev *led)
+{
+	struct bl_trig_notifier *n =
+		(struct bl_trig_notifier *) led->trigger_data;
+
+	if (led->activated) {
+		device_remove_file(led->dev, &dev_attr_inverted);
+		fb_unregister_client(&n->notifier);
+		kfree(n);
+		led->activated = false;
+	}
+}
+
+static struct led_trigger bl_led_trigger = {
+	.name		= "backlight",
+	.activate	= bl_trig_activate,
+	.deactivate	= bl_trig_deactivate
+};
+
+static int __init bl_trig_init(void)
+{
+	return led_trigger_register(&bl_led_trigger);
+}
+
+static void __exit bl_trig_exit(void)
+{
+	led_trigger_unregister(&bl_led_trigger);
+}
+
+module_init(bl_trig_init);
+module_exit(bl_trig_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("Backlight emulation LED trigger");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/leds/trigger/ledtrig-camera.c b/drivers/leds/trigger/ledtrig-camera.c
new file mode 100644
index 000000000..9bd73a8ba
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-camera.c
@@ -0,0 +1,57 @@
+/*
+ * Camera Flash and Torch On/Off Trigger
+ *
+ * based on ledtrig-ide-disk.c
+ *
+ * Copyright 2013 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@ti.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/leds.h>
+
+DEFINE_LED_TRIGGER(ledtrig_flash);
+DEFINE_LED_TRIGGER(ledtrig_torch);
+
+void ledtrig_flash_ctrl(bool on)
+{
+	enum led_brightness brt = on ? LED_FULL : LED_OFF;
+
+	led_trigger_event(ledtrig_flash, brt);
+}
+EXPORT_SYMBOL_GPL(ledtrig_flash_ctrl);
+
+void ledtrig_torch_ctrl(bool on)
+{
+	enum led_brightness brt = on ? LED_FULL : LED_OFF;
+
+	led_trigger_event(ledtrig_torch, brt);
+}
+EXPORT_SYMBOL_GPL(ledtrig_torch_ctrl);
+
+static int __init ledtrig_camera_init(void)
+{
+	led_trigger_register_simple("flash", &ledtrig_flash);
+	led_trigger_register_simple("torch", &ledtrig_torch);
+	return 0;
+}
+module_init(ledtrig_camera_init);
+
+static void __exit ledtrig_camera_exit(void)
+{
+	led_trigger_unregister_simple(ledtrig_torch);
+	led_trigger_unregister_simple(ledtrig_flash);
+}
+module_exit(ledtrig_camera_exit);
+
+MODULE_DESCRIPTION("LED Trigger for Camera Flash/Torch Control");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c
new file mode 100644
index 000000000..aec0f02b6
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-cpu.c
@@ -0,0 +1,166 @@
+/*
+ * ledtrig-cpu.c - LED trigger based on CPU activity
+ *
+ * This LED trigger will be registered for each possible CPU and named as
+ * cpu0, cpu1, cpu2, cpu3, etc.
+ *
+ * It can be bound to any LED just like other triggers using either a
+ * board file or via sysfs interface.
+ *
+ * An API named ledtrig_cpu is exported for any user, who want to add CPU
+ * activity indication in their code
+ *
+ * Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright 2011 - 2012 Bryan Wu <bryan.wu@canonical.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/slab.h>
+#include <linux/percpu.h>
+#include <linux/syscore_ops.h>
+#include <linux/rwsem.h>
+#include <linux/cpu.h>
+#include "../leds.h"
+
+#define MAX_NAME_LEN	8
+
+struct led_trigger_cpu {
+	char name[MAX_NAME_LEN];
+	struct led_trigger *_trig;
+};
+
+static DEFINE_PER_CPU(struct led_trigger_cpu, cpu_trig);
+
+/**
+ * ledtrig_cpu - emit a CPU event as a trigger
+ * @evt: CPU event to be emitted
+ *
+ * Emit a CPU event on a CPU core, which will trigger a
+ * binded LED to turn on or turn off.
+ */
+void ledtrig_cpu(enum cpu_led_event ledevt)
+{
+	struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
+
+	/* Locate the correct CPU LED */
+	switch (ledevt) {
+	case CPU_LED_IDLE_END:
+	case CPU_LED_START:
+		/* Will turn the LED on, max brightness */
+		led_trigger_event(trig->_trig, LED_FULL);
+		break;
+
+	case CPU_LED_IDLE_START:
+	case CPU_LED_STOP:
+	case CPU_LED_HALTED:
+		/* Will turn the LED off */
+		led_trigger_event(trig->_trig, LED_OFF);
+		break;
+
+	default:
+		/* Will leave the LED as it is */
+		break;
+	}
+}
+EXPORT_SYMBOL(ledtrig_cpu);
+
+static int ledtrig_cpu_syscore_suspend(void)
+{
+	ledtrig_cpu(CPU_LED_STOP);
+	return 0;
+}
+
+static void ledtrig_cpu_syscore_resume(void)
+{
+	ledtrig_cpu(CPU_LED_START);
+}
+
+static void ledtrig_cpu_syscore_shutdown(void)
+{
+	ledtrig_cpu(CPU_LED_HALTED);
+}
+
+static struct syscore_ops ledtrig_cpu_syscore_ops = {
+	.shutdown	= ledtrig_cpu_syscore_shutdown,
+	.suspend	= ledtrig_cpu_syscore_suspend,
+	.resume		= ledtrig_cpu_syscore_resume,
+};
+
+static int ledtrig_cpu_notify(struct notifier_block *self,
+					   unsigned long action, void *hcpu)
+{
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_STARTING:
+		ledtrig_cpu(CPU_LED_START);
+		break;
+	case CPU_DYING:
+		ledtrig_cpu(CPU_LED_STOP);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+
+static struct notifier_block ledtrig_cpu_nb = {
+	.notifier_call = ledtrig_cpu_notify,
+};
+
+static int __init ledtrig_cpu_init(void)
+{
+	int cpu;
+
+	/* Supports up to 9999 cpu cores */
+	BUILD_BUG_ON(CONFIG_NR_CPUS > 9999);
+
+	/*
+	 * Registering CPU led trigger for each CPU core here
+	 * ignores CPU hotplug, but after this CPU hotplug works
+	 * fine with this trigger.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+
+		snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu);
+
+		led_trigger_register_simple(trig->name, &trig->_trig);
+	}
+
+	register_syscore_ops(&ledtrig_cpu_syscore_ops);
+	register_cpu_notifier(&ledtrig_cpu_nb);
+
+	pr_info("ledtrig-cpu: registered to indicate activity on CPUs\n");
+
+	return 0;
+}
+module_init(ledtrig_cpu_init);
+
+static void __exit ledtrig_cpu_exit(void)
+{
+	int cpu;
+
+	unregister_cpu_notifier(&ledtrig_cpu_nb);
+
+	for_each_possible_cpu(cpu) {
+		struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+
+		led_trigger_unregister_simple(trig->_trig);
+		trig->_trig = NULL;
+		memset(trig->name, 0, MAX_NAME_LEN);
+	}
+
+	unregister_syscore_ops(&ledtrig_cpu_syscore_ops);
+}
+module_exit(ledtrig_cpu_exit);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
+MODULE_AUTHOR("Bryan Wu <bryan.wu@canonical.com>");
+MODULE_DESCRIPTION("CPU LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-default-on.c b/drivers/leds/trigger/ledtrig-default-on.c
new file mode 100644
index 000000000..6f38f883a
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-default-on.c
@@ -0,0 +1,45 @@
+/*
+ * LED Kernel Default ON Trigger
+ *
+ * Copyright 2008 Nick Forbes <nick.forbes@incepta.com>
+ *
+ * Based on Richard Purdie's ledtrig-timer.c.
+ *
+ * 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/leds.h>
+#include "../leds.h"
+
+static void defon_trig_activate(struct led_classdev *led_cdev)
+{
+	led_set_brightness_async(led_cdev, led_cdev->max_brightness);
+}
+
+static struct led_trigger defon_led_trigger = {
+	.name     = "default-on",
+	.activate = defon_trig_activate,
+};
+
+static int __init defon_trig_init(void)
+{
+	return led_trigger_register(&defon_led_trigger);
+}
+
+static void __exit defon_trig_exit(void)
+{
+	led_trigger_unregister(&defon_led_trigger);
+}
+
+module_init(defon_trig_init);
+module_exit(defon_trig_exit);
+
+MODULE_AUTHOR("Nick Forbes <nick.forbes@incepta.com>");
+MODULE_DESCRIPTION("Default-ON LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
new file mode 100644
index 000000000..4cc704074
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-gpio.c
@@ -0,0 +1,253 @@
+/*
+ * 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_cansleep(gpio_data->gpio);
+	if (gpio_data->inverted)
+		tmp = !tmp;
+
+	if (tmp) {
+		if (gpio_data->desired_brightness)
+			led_set_brightness_async(gpio_data->led,
+					   gpio_data->desired_brightness);
+		else
+			led_set_brightness_async(gpio_data->led, LED_FULL);
+	} else {
+		led_set_brightness_async(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 = kstrtoul(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");
diff --git a/drivers/leds/trigger/ledtrig-heartbeat.c b/drivers/leds/trigger/ledtrig-heartbeat.c
new file mode 100644
index 000000000..fea6871d2
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-heartbeat.c
@@ -0,0 +1,161 @@
+/*
+ * LED Heartbeat Trigger
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * Based on Richard Purdie's ledtrig-timer.c and some arch's
+ * CONFIG_HEARTBEAT code.
+ *
+ * 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/slab.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/leds.h>
+#include <linux/reboot.h>
+#include "../leds.h"
+
+static int panic_heartbeats;
+
+struct heartbeat_trig_data {
+	unsigned int phase;
+	unsigned int period;
+	struct timer_list timer;
+};
+
+static void led_heartbeat_function(unsigned long data)
+{
+	struct led_classdev *led_cdev = (struct led_classdev *) data;
+	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
+	unsigned long brightness = LED_OFF;
+	unsigned long delay = 0;
+
+	if (unlikely(panic_heartbeats)) {
+		led_set_brightness(led_cdev, LED_OFF);
+		return;
+	}
+
+	/* acts like an actual heart beat -- ie thump-thump-pause... */
+	switch (heartbeat_data->phase) {
+	case 0:
+		/*
+		 * The hyperbolic function below modifies the
+		 * heartbeat period length in dependency of the
+		 * current (1min) load. It goes through the points
+		 * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
+		 */
+		heartbeat_data->period = 300 +
+			(6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
+		heartbeat_data->period =
+			msecs_to_jiffies(heartbeat_data->period);
+		delay = msecs_to_jiffies(70);
+		heartbeat_data->phase++;
+		brightness = led_cdev->max_brightness;
+		break;
+	case 1:
+		delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
+		heartbeat_data->phase++;
+		break;
+	case 2:
+		delay = msecs_to_jiffies(70);
+		heartbeat_data->phase++;
+		brightness = led_cdev->max_brightness;
+		break;
+	default:
+		delay = heartbeat_data->period - heartbeat_data->period / 4 -
+			msecs_to_jiffies(70);
+		heartbeat_data->phase = 0;
+		break;
+	}
+
+	led_set_brightness_async(led_cdev, brightness);
+	mod_timer(&heartbeat_data->timer, jiffies + delay);
+}
+
+static void heartbeat_trig_activate(struct led_classdev *led_cdev)
+{
+	struct heartbeat_trig_data *heartbeat_data;
+
+	heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
+	if (!heartbeat_data)
+		return;
+
+	led_cdev->trigger_data = heartbeat_data;
+	setup_timer(&heartbeat_data->timer,
+		    led_heartbeat_function, (unsigned long) led_cdev);
+	heartbeat_data->phase = 0;
+	led_heartbeat_function(heartbeat_data->timer.data);
+	led_cdev->activated = true;
+}
+
+static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
+{
+	struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
+
+	if (led_cdev->activated) {
+		del_timer_sync(&heartbeat_data->timer);
+		kfree(heartbeat_data);
+		led_cdev->activated = false;
+	}
+}
+
+static struct led_trigger heartbeat_led_trigger = {
+	.name     = "heartbeat",
+	.activate = heartbeat_trig_activate,
+	.deactivate = heartbeat_trig_deactivate,
+};
+
+static int heartbeat_reboot_notifier(struct notifier_block *nb,
+				     unsigned long code, void *unused)
+{
+	led_trigger_unregister(&heartbeat_led_trigger);
+	return NOTIFY_DONE;
+}
+
+static int heartbeat_panic_notifier(struct notifier_block *nb,
+				     unsigned long code, void *unused)
+{
+	panic_heartbeats = 1;
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block heartbeat_reboot_nb = {
+	.notifier_call = heartbeat_reboot_notifier,
+};
+
+static struct notifier_block heartbeat_panic_nb = {
+	.notifier_call = heartbeat_panic_notifier,
+};
+
+static int __init heartbeat_trig_init(void)
+{
+	int rc = led_trigger_register(&heartbeat_led_trigger);
+
+	if (!rc) {
+		atomic_notifier_chain_register(&panic_notifier_list,
+					       &heartbeat_panic_nb);
+		register_reboot_notifier(&heartbeat_reboot_nb);
+	}
+	return rc;
+}
+
+static void __exit heartbeat_trig_exit(void)
+{
+	unregister_reboot_notifier(&heartbeat_reboot_nb);
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &heartbeat_panic_nb);
+	led_trigger_unregister(&heartbeat_led_trigger);
+}
+
+module_init(heartbeat_trig_init);
+module_exit(heartbeat_trig_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Heartbeat LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-ide-disk.c b/drivers/leds/trigger/ledtrig-ide-disk.c
new file mode 100644
index 000000000..2cd7c0cf5
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-ide-disk.c
@@ -0,0 +1,47 @@
+/*
+ * LED IDE-Disk Activity Trigger
+ *
+ * Copyright 2006 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <rpurdie@openedhand.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/leds.h>
+
+#define BLINK_DELAY 30
+
+DEFINE_LED_TRIGGER(ledtrig_ide);
+static unsigned long ide_blink_delay = BLINK_DELAY;
+
+void ledtrig_ide_activity(void)
+{
+	led_trigger_blink_oneshot(ledtrig_ide,
+				  &ide_blink_delay, &ide_blink_delay, 0);
+}
+EXPORT_SYMBOL(ledtrig_ide_activity);
+
+static int __init ledtrig_ide_init(void)
+{
+	led_trigger_register_simple("ide-disk", &ledtrig_ide);
+	return 0;
+}
+
+static void __exit ledtrig_ide_exit(void)
+{
+	led_trigger_unregister_simple(ledtrig_ide);
+}
+
+module_init(ledtrig_ide_init);
+module_exit(ledtrig_ide_exit);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
+MODULE_DESCRIPTION("LED IDE Disk Activity Trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-oneshot.c b/drivers/leds/trigger/ledtrig-oneshot.c
new file mode 100644
index 000000000..fbd02cdc3
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-oneshot.c
@@ -0,0 +1,204 @@
+/*
+ * One-shot LED Trigger
+ *
+ * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com>
+ *
+ * Based on ledtrig-timer.c by Richard Purdie <rpurdie@openedhand.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/device.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+#include "../leds.h"
+
+#define DEFAULT_DELAY 100
+
+struct oneshot_trig_data {
+	unsigned int invert;
+};
+
+static ssize_t led_shot(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data;
+
+	led_blink_set_oneshot(led_cdev,
+			&led_cdev->blink_delay_on, &led_cdev->blink_delay_off,
+			oneshot_data->invert);
+
+	/* content is ignored */
+	return size;
+}
+static ssize_t led_invert_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data;
+
+	return sprintf(buf, "%u\n", oneshot_data->invert);
+}
+
+static ssize_t led_invert_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data;
+	unsigned long state;
+	int ret;
+
+	ret = kstrtoul(buf, 0, &state);
+	if (ret)
+		return ret;
+
+	oneshot_data->invert = !!state;
+
+	if (oneshot_data->invert)
+		led_set_brightness_async(led_cdev, LED_FULL);
+	else
+		led_set_brightness_async(led_cdev, LED_OFF);
+
+	return size;
+}
+
+static ssize_t led_delay_on_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
+}
+
+static ssize_t led_delay_on_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	int ret;
+
+	ret = kstrtoul(buf, 0, &state);
+	if (ret)
+		return ret;
+
+	led_cdev->blink_delay_on = state;
+
+	return size;
+}
+static ssize_t led_delay_off_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
+}
+
+static ssize_t led_delay_off_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	int ret;
+
+	ret = kstrtoul(buf, 0, &state);
+	if (ret)
+		return ret;
+
+	led_cdev->blink_delay_off = state;
+
+	return size;
+}
+
+static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
+static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
+static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
+static DEVICE_ATTR(shot, 0200, NULL, led_shot);
+
+static void oneshot_trig_activate(struct led_classdev *led_cdev)
+{
+	struct oneshot_trig_data *oneshot_data;
+	int rc;
+
+	oneshot_data = kzalloc(sizeof(*oneshot_data), GFP_KERNEL);
+	if (!oneshot_data)
+		return;
+
+	led_cdev->trigger_data = oneshot_data;
+
+	rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
+	if (rc)
+		goto err_out_trig_data;
+	rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
+	if (rc)
+		goto err_out_delayon;
+	rc = device_create_file(led_cdev->dev, &dev_attr_invert);
+	if (rc)
+		goto err_out_delayoff;
+	rc = device_create_file(led_cdev->dev, &dev_attr_shot);
+	if (rc)
+		goto err_out_invert;
+
+	led_cdev->blink_delay_on = DEFAULT_DELAY;
+	led_cdev->blink_delay_off = DEFAULT_DELAY;
+
+	led_cdev->activated = true;
+
+	return;
+
+err_out_invert:
+	device_remove_file(led_cdev->dev, &dev_attr_invert);
+err_out_delayoff:
+	device_remove_file(led_cdev->dev, &dev_attr_delay_off);
+err_out_delayon:
+	device_remove_file(led_cdev->dev, &dev_attr_delay_on);
+err_out_trig_data:
+	kfree(led_cdev->trigger_data);
+}
+
+static void oneshot_trig_deactivate(struct led_classdev *led_cdev)
+{
+	struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data;
+
+	if (led_cdev->activated) {
+		device_remove_file(led_cdev->dev, &dev_attr_delay_on);
+		device_remove_file(led_cdev->dev, &dev_attr_delay_off);
+		device_remove_file(led_cdev->dev, &dev_attr_invert);
+		device_remove_file(led_cdev->dev, &dev_attr_shot);
+		kfree(oneshot_data);
+		led_cdev->activated = false;
+	}
+
+	/* Stop blinking */
+	led_set_brightness(led_cdev, LED_OFF);
+}
+
+static struct led_trigger oneshot_led_trigger = {
+	.name     = "oneshot",
+	.activate = oneshot_trig_activate,
+	.deactivate = oneshot_trig_deactivate,
+};
+
+static int __init oneshot_trig_init(void)
+{
+	return led_trigger_register(&oneshot_led_trigger);
+}
+
+static void __exit oneshot_trig_exit(void)
+{
+	led_trigger_unregister(&oneshot_led_trigger);
+}
+
+module_init(oneshot_trig_init);
+module_exit(oneshot_trig_exit);
+
+MODULE_AUTHOR("Fabio Baltieri <fabio.baltieri@gmail.com>");
+MODULE_DESCRIPTION("One-shot LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-timer.c b/drivers/leds/trigger/ledtrig-timer.c
new file mode 100644
index 000000000..8d09327b5
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-timer.c
@@ -0,0 +1,130 @@
+/*
+ * LED Kernel Timer Trigger
+ *
+ * Copyright 2005-2006 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <rpurdie@openedhand.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/device.h>
+#include <linux/ctype.h>
+#include <linux/leds.h>
+
+static ssize_t led_delay_on_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
+}
+
+static ssize_t led_delay_on_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	ssize_t ret = -EINVAL;
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
+	led_cdev->blink_delay_on = state;
+
+	return size;
+}
+
+static ssize_t led_delay_off_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
+}
+
+static ssize_t led_delay_off_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	ssize_t ret = -EINVAL;
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
+	led_cdev->blink_delay_off = state;
+
+	return size;
+}
+
+static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
+static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
+
+static void timer_trig_activate(struct led_classdev *led_cdev)
+{
+	int rc;
+
+	led_cdev->trigger_data = NULL;
+
+	rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
+	if (rc)
+		return;
+	rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
+	if (rc)
+		goto err_out_delayon;
+
+	led_blink_set(led_cdev, &led_cdev->blink_delay_on,
+		      &led_cdev->blink_delay_off);
+	led_cdev->activated = true;
+
+	return;
+
+err_out_delayon:
+	device_remove_file(led_cdev->dev, &dev_attr_delay_on);
+}
+
+static void timer_trig_deactivate(struct led_classdev *led_cdev)
+{
+	if (led_cdev->activated) {
+		device_remove_file(led_cdev->dev, &dev_attr_delay_on);
+		device_remove_file(led_cdev->dev, &dev_attr_delay_off);
+		led_cdev->activated = false;
+	}
+
+	/* Stop blinking */
+	led_set_brightness(led_cdev, LED_OFF);
+}
+
+static struct led_trigger timer_led_trigger = {
+	.name     = "timer",
+	.activate = timer_trig_activate,
+	.deactivate = timer_trig_deactivate,
+};
+
+static int __init timer_trig_init(void)
+{
+	return led_trigger_register(&timer_led_trigger);
+}
+
+static void __exit timer_trig_exit(void)
+{
+	led_trigger_unregister(&timer_led_trigger);
+}
+
+module_init(timer_trig_init);
+module_exit(timer_trig_exit);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
+MODULE_DESCRIPTION("Timer LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/drivers/leds/trigger/ledtrig-transient.c b/drivers/leds/trigger/ledtrig-transient.c
new file mode 100644
index 000000000..3c34de404
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-transient.c
@@ -0,0 +1,239 @@
+/*
+ * LED Kernel Transient Trigger
+ *
+ * Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com>
+ *
+ * Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's
+ * ledtrig-heartbeat.c
+ * Design and use-case input from Jonas Bonn <jonas@southpole.se> and
+ * Neil Brown <neilb@suse.de>
+ *
+ * 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.
+ *
+ */
+/*
+ * Transient trigger allows one shot timer activation. Please refer to
+ * Documentation/leds/ledtrig-transient.txt for details
+*/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/leds.h>
+#include "../leds.h"
+
+struct transient_trig_data {
+	int activate;
+	int state;
+	int restore_state;
+	unsigned long duration;
+	struct timer_list timer;
+};
+
+static void transient_timer_function(unsigned long data)
+{
+	struct led_classdev *led_cdev = (struct led_classdev *) data;
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+	transient_data->activate = 0;
+	led_set_brightness_async(led_cdev, transient_data->restore_state);
+}
+
+static ssize_t transient_activate_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+	return sprintf(buf, "%d\n", transient_data->activate);
+}
+
+static ssize_t transient_activate_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+	unsigned long state;
+	ssize_t ret;
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	if (state != 1 && state != 0)
+		return -EINVAL;
+
+	/* cancel the running timer */
+	if (state == 0 && transient_data->activate == 1) {
+		del_timer(&transient_data->timer);
+		transient_data->activate = state;
+		led_set_brightness_async(led_cdev,
+					transient_data->restore_state);
+		return size;
+	}
+
+	/* start timer if there is no active timer */
+	if (state == 1 && transient_data->activate == 0 &&
+	    transient_data->duration != 0) {
+		transient_data->activate = state;
+		led_set_brightness_async(led_cdev, transient_data->state);
+		transient_data->restore_state =
+		    (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
+		mod_timer(&transient_data->timer,
+			  jiffies + transient_data->duration);
+	}
+
+	/* state == 0 && transient_data->activate == 0
+		timer is not active - just return */
+	/* state == 1 && transient_data->activate == 1
+		timer is already active - just return */
+
+	return size;
+}
+
+static ssize_t transient_duration_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+	return sprintf(buf, "%lu\n", transient_data->duration);
+}
+
+static ssize_t transient_duration_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+	unsigned long state;
+	ssize_t ret;
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	transient_data->duration = state;
+	return size;
+}
+
+static ssize_t transient_state_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+	int state;
+
+	state = (transient_data->state == LED_FULL) ? 1 : 0;
+	return sprintf(buf, "%d\n", state);
+}
+
+static ssize_t transient_state_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+	unsigned long state;
+	ssize_t ret;
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	if (state != 1 && state != 0)
+		return -EINVAL;
+
+	transient_data->state = (state == 1) ? LED_FULL : LED_OFF;
+	return size;
+}
+
+static DEVICE_ATTR(activate, 0644, transient_activate_show,
+		   transient_activate_store);
+static DEVICE_ATTR(duration, 0644, transient_duration_show,
+		   transient_duration_store);
+static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store);
+
+static void transient_trig_activate(struct led_classdev *led_cdev)
+{
+	int rc;
+	struct transient_trig_data *tdata;
+
+	tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL);
+	if (!tdata) {
+		dev_err(led_cdev->dev,
+			"unable to allocate transient trigger\n");
+		return;
+	}
+	led_cdev->trigger_data = tdata;
+
+	rc = device_create_file(led_cdev->dev, &dev_attr_activate);
+	if (rc)
+		goto err_out;
+
+	rc = device_create_file(led_cdev->dev, &dev_attr_duration);
+	if (rc)
+		goto err_out_duration;
+
+	rc = device_create_file(led_cdev->dev, &dev_attr_state);
+	if (rc)
+		goto err_out_state;
+
+	setup_timer(&tdata->timer, transient_timer_function,
+		    (unsigned long) led_cdev);
+	led_cdev->activated = true;
+
+	return;
+
+err_out_state:
+	device_remove_file(led_cdev->dev, &dev_attr_duration);
+err_out_duration:
+	device_remove_file(led_cdev->dev, &dev_attr_activate);
+err_out:
+	dev_err(led_cdev->dev, "unable to register transient trigger\n");
+	led_cdev->trigger_data = NULL;
+	kfree(tdata);
+}
+
+static void transient_trig_deactivate(struct led_classdev *led_cdev)
+{
+	struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+	if (led_cdev->activated) {
+		del_timer_sync(&transient_data->timer);
+		led_set_brightness_async(led_cdev,
+					transient_data->restore_state);
+		device_remove_file(led_cdev->dev, &dev_attr_activate);
+		device_remove_file(led_cdev->dev, &dev_attr_duration);
+		device_remove_file(led_cdev->dev, &dev_attr_state);
+		led_cdev->trigger_data = NULL;
+		led_cdev->activated = false;
+		kfree(transient_data);
+	}
+}
+
+static struct led_trigger transient_trigger = {
+	.name     = "transient",
+	.activate = transient_trig_activate,
+	.deactivate = transient_trig_deactivate,
+};
+
+static int __init transient_trig_init(void)
+{
+	return led_trigger_register(&transient_trigger);
+}
+
+static void __exit transient_trig_exit(void)
+{
+	led_trigger_unregister(&transient_trigger);
+}
+
+module_init(transient_trig_init);
+module_exit(transient_trig_exit);
+
+MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>");
+MODULE_DESCRIPTION("Transient LED trigger");
+MODULE_LICENSE("GPL");