mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	Allow initialization of delays used in timer trigger from Device Tree property. This is especially useful for embedded systems where the trigger might be used early, before bringing up user-space. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
		
			
				
	
	
		
			138 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			138 lines
		
	
	
	
		
			3.3 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/slab.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 = led_trigger_get_led(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 = led_trigger_get_led(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 = led_trigger_get_led(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 = led_trigger_get_led(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 struct attribute *timer_trig_attrs[] = {
 | 
						|
	&dev_attr_delay_on.attr,
 | 
						|
	&dev_attr_delay_off.attr,
 | 
						|
	NULL
 | 
						|
};
 | 
						|
ATTRIBUTE_GROUPS(timer_trig);
 | 
						|
 | 
						|
static void pattern_init(struct led_classdev *led_cdev)
 | 
						|
{
 | 
						|
	u32 *pattern;
 | 
						|
	unsigned int size = 0;
 | 
						|
 | 
						|
	pattern = led_get_default_pattern(led_cdev, &size);
 | 
						|
	if (!pattern)
 | 
						|
		return;
 | 
						|
 | 
						|
	if (size != 2) {
 | 
						|
		dev_warn(led_cdev->dev,
 | 
						|
			 "Expected 2 but got %u values for delays pattern\n",
 | 
						|
			 size);
 | 
						|
		goto out;
 | 
						|
	}
 | 
						|
 | 
						|
	led_cdev->blink_delay_on = pattern[0];
 | 
						|
	led_cdev->blink_delay_off = pattern[1];
 | 
						|
	/* led_blink_set() called by caller */
 | 
						|
 | 
						|
out:
 | 
						|
	kfree(pattern);
 | 
						|
}
 | 
						|
 | 
						|
static int timer_trig_activate(struct led_classdev *led_cdev)
 | 
						|
{
 | 
						|
	if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
 | 
						|
		pattern_init(led_cdev);
 | 
						|
		/*
 | 
						|
		 * Mark as initialized even on pattern_init() error because
 | 
						|
		 * any consecutive call to it would produce the same error.
 | 
						|
		 */
 | 
						|
		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
 | 
						|
	}
 | 
						|
 | 
						|
	led_blink_set(led_cdev, &led_cdev->blink_delay_on,
 | 
						|
		      &led_cdev->blink_delay_off);
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
static void timer_trig_deactivate(struct led_classdev *led_cdev)
 | 
						|
{
 | 
						|
	/* 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,
 | 
						|
	.groups = timer_trig_groups,
 | 
						|
};
 | 
						|
module_led_trigger(timer_led_trigger);
 | 
						|
 | 
						|
MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 | 
						|
MODULE_DESCRIPTION("Timer LED trigger");
 | 
						|
MODULE_LICENSE("GPL v2");
 |