| /* |
| * 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" |
| |
| #define LED_BUFF_SIZE 50 |
| |
| 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 snprintf(buf, LED_BUFF_SIZE, "%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; |
| |
| 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_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; |
| unsigned long state = 0; |
| |
| ret = strict_strtoul(buf, 10, &state); |
| if (!ret) { |
| ret = size; |
| if (state > LED_FULL) |
| state = LED_FULL; |
| led_cdev->max_brightness = state; |
| led_set_brightness(led_cdev, led_cdev->brightness); |
| } |
| |
| 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 snprintf(buf, LED_BUFF_SIZE, "%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, 0644, led_max_brightness_show, |
| led_max_brightness_store), |
| #ifdef CONFIG_LEDS_TRIGGERS |
| __ATTR(trigger, 0644, led_trigger_show, led_trigger_store), |
| #endif |
| __ATTR_NULL, |
| }; |
| |
| static void led_timer_function(unsigned long data) |
| { |
| struct led_classdev *led_cdev = (void *)data; |
| unsigned long brightness; |
| unsigned long delay; |
| |
| if (!led_cdev->blink_delay_on || !led_cdev->blink_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 = led_cdev->blink_brightness; |
| delay = led_cdev->blink_delay_on; |
| } else { |
| /* Store the current brightness value to be able |
| * to restore it when the delay_off period is over. |
| */ |
| led_cdev->blink_brightness = brightness; |
| brightness = LED_OFF; |
| delay = led_cdev->blink_delay_off; |
| } |
| |
| led_set_brightness(led_cdev, brightness); |
| |
| mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); |
| } |
| |
| static void led_stop_software_blink(struct led_classdev *led_cdev) |
| { |
| /* deactivate previous settings */ |
| del_timer_sync(&led_cdev->blink_timer); |
| led_cdev->blink_delay_on = 0; |
| led_cdev->blink_delay_off = 0; |
| } |
| |
| static void led_set_software_blink(struct led_classdev *led_cdev, |
| unsigned long delay_on, |
| unsigned long delay_off) |
| { |
| int current_brightness; |
| |
| current_brightness = led_get_brightness(led_cdev); |
| if (current_brightness) |
| led_cdev->blink_brightness = current_brightness; |
| if (!led_cdev->blink_brightness) |
| led_cdev->blink_brightness = led_cdev->max_brightness; |
| |
| if (led_get_trigger_data(led_cdev) && |
| delay_on == led_cdev->blink_delay_on && |
| delay_off == led_cdev->blink_delay_off) |
| return; |
| |
| led_stop_software_blink(led_cdev); |
| |
| led_cdev->blink_delay_on = delay_on; |
| led_cdev->blink_delay_off = delay_off; |
| |
| /* never on - don't blink */ |
| if (!delay_on) |
| return; |
| |
| /* never off - just set to brightness */ |
| if (!delay_off) { |
| led_set_brightness(led_cdev, led_cdev->blink_brightness); |
| return; |
| } |
| |
| mod_timer(&led_cdev->blink_timer, jiffies + 1); |
| } |
| |
| |
| /** |
| * 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); |
| |
| init_timer(&led_cdev->blink_timer); |
| led_cdev->blink_timer.function = led_timer_function; |
| led_cdev->blink_timer.data = (unsigned long)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 |
| |
| /* Stop blinking */ |
| led_brightness_set(led_cdev, LED_OFF); |
| |
| 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); |
| |
| void led_blink_set(struct led_classdev *led_cdev, |
| unsigned long *delay_on, |
| unsigned long *delay_off) |
| { |
| del_timer_sync(&led_cdev->blink_timer); |
| |
| if (led_cdev->blink_set && |
| !led_cdev->blink_set(led_cdev, delay_on, delay_off)) |
| return; |
| |
| /* blink with 1 Hz as default if nothing specified */ |
| if (!*delay_on && !*delay_off) |
| *delay_on = *delay_off = 500; |
| |
| led_set_software_blink(led_cdev, *delay_on, *delay_off); |
| } |
| EXPORT_SYMBOL(led_blink_set); |
| |
| void led_brightness_set(struct led_classdev *led_cdev, |
| enum led_brightness brightness) |
| { |
| led_stop_software_blink(led_cdev); |
| led_cdev->brightness_set(led_cdev, brightness); |
| } |
| EXPORT_SYMBOL(led_brightness_set); |
| |
| 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"); |