diff options
Diffstat (limited to 'drivers/leds/led-class.c')
| -rw-r--r-- | drivers/leds/led-class.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c new file mode 100644 index 0000000..6c4a326 --- /dev/null +++ b/drivers/leds/led-class.c @@ -0,0 +1,190 @@ +/* + * 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; + + if (*after && 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 DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store); +#ifdef CONFIG_LEDS_TRIGGERS +static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); +#endif + +/** + * 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); + +/** + * led_classdev_register - register a new object of led_classdev class. + * @dev: 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) +{ + int rc; + + 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); + + /* register the attributes */ + rc = device_create_file(led_cdev->dev, &dev_attr_brightness); + if (rc) + goto err_out; + +#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); + + led_update_brightness(led_cdev); + +#ifdef CONFIG_LEDS_TRIGGERS + rc = device_create_file(led_cdev->dev, &dev_attr_trigger); + if (rc) + goto err_out_led_list; + + led_trigger_set_default(led_cdev); +#endif + + printk(KERN_INFO "Registered led device: %s\n", + led_cdev->name); + + return 0; + +#ifdef CONFIG_LEDS_TRIGGERS +err_out_led_list: + device_remove_file(led_cdev->dev, &dev_attr_brightness); + list_del(&led_cdev->node); +#endif +err_out: + device_unregister(led_cdev->dev); + return rc; +} +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) +{ + device_remove_file(led_cdev->dev, &dev_attr_brightness); +#ifdef CONFIG_LEDS_TRIGGERS + device_remove_file(led_cdev->dev, &dev_attr_trigger); + 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); + 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"); |
