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linux/drivers/leds/ledtrig-timer.c
Esben Haabendal fff26f8141 leds: support automatic start of blinking with ledtrig-timer
By setting initial values blink_delay_on and blink_delay_off in a
led_classdev struct, this change starts the blinking when the led is
initialized.

With this patch, you can initialize blink_delay_on and blink_delay_off in
led_classdev with default_trigger set to "timer", and the led will start
up blinking.  The current ledtrig-timer implementation ignores any initial
blink_delay_on/blink_delay_off settings, and requires setting
blink_delay_on/blink_delay_off (typically from userspace) before the led
blinks.

Signed-off-by: Esben Haabendal <eha@doredevelopment.dk>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:49 -07:00

138 lines
3.2 KiB
C

/*
* 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>
#include "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);
int ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
if (isspace(*after))
count++;
if (count == size) {
led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
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);
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);
int ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
if (isspace(*after))
count++;
if (count == size) {
led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
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)
{
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->trigger_data = (void *)1;
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->trigger_data) {
device_remove_file(led_cdev->dev, &dev_attr_delay_on);
device_remove_file(led_cdev->dev, &dev_attr_delay_off);
}
/* Stop blinking */
led_brightness_set(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");