linux/drivers/leds/led-class.c

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/*
* LED Class Core
*
* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
* Copyright (C) 2005-2007 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/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include "leds.h"
static struct class *leds_class;
static void led_update_brightness(struct led_classdev *led_cdev)
{
if (led_cdev->brightness_get)
led_cdev->brightness = led_cdev->brightness_get(led_cdev);
}
static ssize_t led_brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
/* no lock needed for this */
led_update_brightness(led_cdev);
return sprintf(buf, "%u\n", led_cdev->brightness);
}
static ssize_t led_brightness_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
ssize_t ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
tree-wide: convert open calls to remove spaces to skip_spaces() lib function Makes use of skip_spaces() defined in lib/string.c for removing leading spaces from strings all over the tree. It decreases lib.a code size by 47 bytes and reuses the function tree-wide: text data bss dec hex filename 64688 584 592 65864 10148 (TOTALS-BEFORE) 64641 584 592 65817 10119 (TOTALS-AFTER) Also, while at it, if we see (*str && isspace(*str)), we can be sure to remove the first condition (*str) as the second one (isspace(*str)) also evaluates to 0 whenever *str == 0, making it redundant. In other words, "a char equals zero is never a space". Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below, and found occurrences of this pattern on 3 more files: drivers/leds/led-class.c drivers/leds/ledtrig-timer.c drivers/video/output.c @@ expression str; @@ ( // ignore skip_spaces cases while (*str && isspace(*str)) { \(str++;\|++str;\) } | - *str && isspace(*str) ) Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Julia Lawall <julia@diku.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Neil Brown <neilb@suse.de> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: David Howells <dhowells@redhat.com> Cc: <linux-ext4@vger.kernel.org> Cc: Samuel Ortiz <samuel@sortiz.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 02:01:06 +00:00
if (isspace(*after))
count++;
if (count == size) {
ret = count;
if (state == LED_OFF)
led_trigger_remove(led_cdev);
led_set_brightness(led_cdev, state);
}
return ret;
}
static ssize_t led_max_brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", led_cdev->max_brightness);
}
static struct device_attribute led_class_attrs[] = {
__ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
__ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
#ifdef CONFIG_LEDS_TRIGGERS
__ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
#endif
__ATTR_NULL,
};
/**
* led_classdev_suspend - suspend an led_classdev.
* @led_cdev: the led_classdev to suspend.
*/
void led_classdev_suspend(struct led_classdev *led_cdev)
{
led_cdev->flags |= LED_SUSPENDED;
led_cdev->brightness_set(led_cdev, 0);
}
EXPORT_SYMBOL_GPL(led_classdev_suspend);
/**
* led_classdev_resume - resume an led_classdev.
* @led_cdev: the led_classdev to resume.
*/
void led_classdev_resume(struct led_classdev *led_cdev)
{
led_cdev->brightness_set(led_cdev, led_cdev->brightness);
led_cdev->flags &= ~LED_SUSPENDED;
}
EXPORT_SYMBOL_GPL(led_classdev_resume);
static int led_suspend(struct device *dev, pm_message_t state)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
led_classdev_suspend(led_cdev);
return 0;
}
static int led_resume(struct device *dev)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
led_classdev_resume(led_cdev);
return 0;
}
/**
* led_classdev_register - register a new object of led_classdev class.
* @parent: The device to register.
* @led_cdev: the led_classdev structure for this device.
*/
int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
{
led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
"%s", led_cdev->name);
if (IS_ERR(led_cdev->dev))
return PTR_ERR(led_cdev->dev);
#ifdef CONFIG_LEDS_TRIGGERS
init_rwsem(&led_cdev->trigger_lock);
#endif
/* add to the list of leds */
down_write(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
up_write(&leds_list_lock);
if (!led_cdev->max_brightness)
led_cdev->max_brightness = LED_FULL;
led_update_brightness(led_cdev);
#ifdef CONFIG_LEDS_TRIGGERS
led_trigger_set_default(led_cdev);
#endif
printk(KERN_DEBUG "Registered led device: %s\n",
led_cdev->name);
return 0;
}
EXPORT_SYMBOL_GPL(led_classdev_register);
/**
* led_classdev_unregister - unregisters a object of led_properties class.
* @led_cdev: the led device to unregister
*
* Unregisters a previously registered via led_classdev_register object.
*/
void led_classdev_unregister(struct led_classdev *led_cdev)
{
#ifdef CONFIG_LEDS_TRIGGERS
down_write(&led_cdev->trigger_lock);
if (led_cdev->trigger)
led_trigger_set(led_cdev, NULL);
up_write(&led_cdev->trigger_lock);
#endif
device_unregister(led_cdev->dev);
down_write(&leds_list_lock);
list_del(&led_cdev->node);
up_write(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_classdev_unregister);
static int __init leds_init(void)
{
leds_class = class_create(THIS_MODULE, "leds");
if (IS_ERR(leds_class))
return PTR_ERR(leds_class);
leds_class->suspend = led_suspend;
leds_class->resume = led_resume;
leds_class->dev_attrs = led_class_attrs;
return 0;
}
static void __exit leds_exit(void)
{
class_destroy(leds_class);
}
subsys_initcall(leds_init);
module_exit(leds_exit);
MODULE_AUTHOR("John Lenz, Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Class Interface");