/*
* 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/jiffies.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/ctype.h>
#include <linux/leds.h>
#include "leds.h"
struct timer_trig_data {
int brightness_on; /* LED brightness during "on" period.
* (LED_OFF < brightness_on <= LED_FULL)
*/
unsigned long delay_on; /* milliseconds on */
unsigned long delay_off; /* milliseconds off */
struct timer_list timer;
};
static void led_timer_function(unsigned long data)
{
struct led_classdev *led_cdev = (struct led_classdev *) data;
struct timer_trig_data *timer_data = led_cdev->trigger_data;
unsigned long brightness;
unsigned long delay;
if (!timer_data->delay_on || !timer_data->delay_off) {
led_set_brightness(led_cdev, LED_OFF);
return;
}
brightness = led_get_brightness(led_cdev);
if (!brightness) {
/* Time to switch the LED on. */
brightness = timer_data->brightness_on;
delay = timer_data->delay_on;
} else {
/* Store the current brightness value to be able
* to restore it when the delay_off period is over.
*/
timer_data->brightness_on = brightness;
brightness = LED_OFF;
delay = timer_data->delay_off;
}
led_set_brightness(led_cdev, brightness);
mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
}
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);
struct timer_trig_data *timer_data = led_cdev->trigger_data;
return sprintf(buf, "%lu\n", timer_data->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);
struct timer_trig_data *timer_data = led_cdev->trigger_data;
int ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
if (*after && isspace(*after))
count++;
if (count == size) {
if (timer_data->delay_on != state) {
/* the new value differs from the previous */
timer_data->delay_on = state;
/* deactivate previous settings */
del_timer_sync(&timer_data->timer);
/* try to activate hardware acceleration, if any */
if (!led_cdev->blink_set ||
led_cdev->blink_set(led_cdev,
&timer_data->delay_on, &timer_data->delay_off)) {
/* no hardware acceleration, blink via timer */
mod_timer(&timer_data->timer, jiffies + 1);
}
}
ret = count;
}
return ret;
}
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);
struct timer_trig_data *timer_data = led_cdev->trigger_data;
return sprintf(buf, "%lu\n", timer_data->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);
struct timer_trig_data *timer_data = led_cdev->trigger_data;
int ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
if (*after && isspace(*after))
count++;
if (count == size) {
if (timer_data->delay_off != state) {
/* the new value differs from the previous */
timer_data->delay_off = state;
/* deactivate previous settings */
del_timer_sync(&timer_data->timer);
/* try to activate hardware acceleration, if any */
if (!led_cdev->blink_set ||
led_cdev->blink_set(led_cdev,
&timer_data->delay_on, &timer_data->delay_off)) {
/* no hardware acceleration, blink via timer */
mod_timer(&timer_data->timer, jiffies + 1);
}
}
ret = count;
}
return ret;
}
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)
{
struct timer_trig_data *timer_data;
int rc;
timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
if (!timer_data)
return;
timer_data->brightness_on = led_get_brightness(led_cdev);
if (timer_data->brightness_on == LED_OFF)
timer_data->brightness_on = LED_FULL;
led_cdev->trigger_data = timer_data;
init_timer(&timer_data->timer);
timer_data->timer.function = led_timer_function;
timer_data->timer.data = (unsigned long) led_cdev;
rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
if (rc)
goto err_out;
rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
if (rc)
goto err_out_delayon;
/* If there is hardware support for blinking, start one
* user friendly blink rate chosen by the driver.
*/
if (led_cdev->blink_set)
led_cdev->blink_set(led_cdev,
&timer_data->delay_on, &timer_data->delay_off);
return;
err_out_delayon:
device_remove_file(led_cdev->dev, &dev_attr_delay_on);
err_out:
led_cdev->trigger_data = NULL;
kfree(timer_data);
}
static void timer_trig_deactivate(struct led_classdev *led_cdev)
{
struct timer_trig_data *timer_data = led_cdev->trigger_data;
if (timer_data) {
device_remove_file(led_cdev->dev, &dev_attr_delay_on);
device_remove_file(led_cdev->dev, &dev_attr_delay_off);
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);
MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
MODULE_DESCRIPTION("Timer LED trigger");
MODULE_LICENSE("GPL");
