Add an example of a complex LED trigger in the form of a generic timer
which triggers any LED its attached to at a user specified frequency.
Signed-off-by: Richard Purdie <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Index: linux-2.6.15-rc2/drivers/leds/trig_timer.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15-rc2/drivers/leds/trig_timer.c 2005-11-30 15:47:06.000000000 +0000
@@ -0,0 +1,133 @@
+/*
+ * LED Kernel Timer Trigger
+ *
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <[email protected]>
+ *
+ * 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/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/sysdev.h>
+#include <linux/timer.h>
+#include <linux/leds.h>
+#include "leds.h"
+
+struct timer_trig_data {
+ unsigned long frequency; /* frequency of blinking, in milliseconds */
+ struct timer_list timer;
+};
+
+static void leds_timer_function(unsigned long data)
+{
+ struct led_device *led_dev = (struct led_device *) data;
+ struct timer_trig_data *timer_data = led_dev->trigger_data;
+ unsigned long value = 0;
+
+ write_lock(&led_dev->lock);
+
+ if (!timer_data->frequency) {
+ leds_set_brightness(led_dev, 0);
+ write_unlock(&led_dev->lock);
+ return;
+ }
+
+ if (!led_dev->brightness)
+ value = 100;
+
+ leds_set_brightness(led_dev, value);
+
+ mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(timer_data->frequency));
+ write_unlock(&led_dev->lock);
+}
+
+static ssize_t leds_show_frequency(struct class_device *dev, char *buf)
+{
+ struct led_device *led_dev = dev->class_data;
+ struct timer_trig_data *timer_data = led_dev->trigger_data;
+
+ read_lock(&led_dev->lock);
+ sprintf(buf, "%lu\n", timer_data->frequency);
+ read_unlock(&led_dev->lock);
+
+ return strlen(buf) + 1;
+}
+
+static ssize_t leds_store_frequency(struct class_device *dev, const char *buf, size_t size)
+{
+ struct led_device *led_dev = dev->class_data;
+ struct timer_trig_data *timer_data = led_dev->trigger_data;
+ int ret = -EINVAL;
+ char *after;
+
+ unsigned long state = simple_strtoul(buf, &after, 10);
+ if (after - buf > 0) {
+ ret = after - buf;
+ write_lock(&led_dev->lock);
+ timer_data->frequency = state;
+ mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(timer_data->frequency));
+ write_unlock(&led_dev->lock);
+ }
+
+ return ret;
+}
+
+static CLASS_DEVICE_ATTR(frequency, 0644, leds_show_frequency, leds_store_frequency);
+
+void timer_trig_activate(struct led_device *led_dev)
+{
+ struct timer_trig_data *timer_data;
+
+ timer_data = kmalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
+ if (!timer_data)
+ return;
+
+ led_dev->trigger_data = timer_data;
+ timer_data->frequency = 0;
+
+ init_timer(&timer_data->timer);
+ timer_data->timer.function = leds_timer_function;
+ timer_data->timer.data = (unsigned long) led_dev;
+ timer_data->timer.expires = 0;
+
+ class_device_create_file(led_dev->class_dev, &class_device_attr_frequency);
+}
+
+void timer_trig_deactivate(struct led_device *led_dev)
+{
+ struct timer_trig_data *timer_data = led_dev->trigger_data;
+ if (timer_data) {
+ class_device_remove_file(led_dev->class_dev, &class_device_attr_frequency);
+ del_timer_sync(&timer_data->timer);
+ kfree(timer_data);
+ }
+}
+
+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);
Index: linux-2.6.15-rc2/drivers/leds/Kconfig
===================================================================
--- linux-2.6.15-rc2.orig/drivers/leds/Kconfig 2005-11-30 15:46:48.000000000 +0000
+++ linux-2.6.15-rc2/drivers/leds/Kconfig 2005-11-30 15:47:37.000000000 +0000
@@ -22,5 +22,12 @@
These triggers allow kernel events to drive the LEDs and can
be configured via sysfs. If unsure, say Y.
+config LEDS_TRIGGER_TIMER
+ tristate "LED Timer Trigger"
+ depends LEDS_TRIGGERS
+ help
+ This allows LEDs to be controlled by a programmable timer
+ via sysfs. If unsure, say Y.
+
endmenu
Index: linux-2.6.15-rc2/drivers/leds/Makefile
===================================================================
--- linux-2.6.15-rc2.orig/drivers/leds/Makefile 2005-11-30 15:46:56.000000000 +0000
+++ linux-2.6.15-rc2/drivers/leds/Makefile 2005-11-30 15:47:29.000000000 +0000
@@ -3,3 +3,6 @@
obj-$(CONFIG_NEW_LEDS) += led_core.o
obj-$(CONFIG_LEDS_CLASS) += led_class.o
obj-$(CONFIG_LEDS_TRIGGERS) += led_triggers.o
+
+# LED Triggers
+obj-$(CONFIG_LEDS_TRIGGER_TIMER) += trig_timer.o
-
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