| /* |
| * 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/ctype.h> |
| #include <linux/device.h> |
| #include <linux/err.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/leds.h> |
| #include <linux/list.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/timer.h> |
| #include "leds.h" |
| |
| static struct class *leds_class; |
| |
| static ssize_t 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 brightness_store(struct device *dev, |
| struct device_attribute *attr, const char *buf, size_t size) |
| { |
| struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| unsigned long state; |
| ssize_t ret; |
| |
| mutex_lock(&led_cdev->led_access); |
| |
| if (led_sysfs_is_disabled(led_cdev)) { |
| ret = -EBUSY; |
| goto unlock; |
| } |
| |
| ret = kstrtoul(buf, 10, &state); |
| if (ret) |
| goto unlock; |
| |
| if (state == LED_OFF) |
| led_trigger_remove(led_cdev); |
| led_set_brightness(led_cdev, state); |
| |
| ret = size; |
| unlock: |
| mutex_unlock(&led_cdev->led_access); |
| return ret; |
| } |
| static DEVICE_ATTR_RW(brightness); |
| |
| static ssize_t 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 DEVICE_ATTR_RO(max_brightness); |
| |
| #ifdef CONFIG_LEDS_TRIGGERS |
| static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); |
| static struct attribute *led_trigger_attrs[] = { |
| &dev_attr_trigger.attr, |
| NULL, |
| }; |
| static const struct attribute_group led_trigger_group = { |
| .attrs = led_trigger_attrs, |
| }; |
| #endif |
| |
| static struct attribute *led_class_attrs[] = { |
| &dev_attr_brightness.attr, |
| &dev_attr_max_brightness.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group led_group = { |
| .attrs = led_class_attrs, |
| }; |
| |
| static const struct attribute_group *led_groups[] = { |
| &led_group, |
| #ifdef CONFIG_LEDS_TRIGGERS |
| &led_trigger_group, |
| #endif |
| 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_async(led_cdev, LED_OFF); |
| return; |
| } |
| |
| if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) { |
| led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; |
| 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_async(led_cdev, brightness); |
| |
| /* Return in next iteration if led is in one-shot mode and we are in |
| * the final blink state so that the led is toggled each delay_on + |
| * delay_off milliseconds in worst case. |
| */ |
| if (led_cdev->flags & LED_BLINK_ONESHOT) { |
| if (led_cdev->flags & LED_BLINK_INVERT) { |
| if (brightness) |
| led_cdev->flags |= LED_BLINK_ONESHOT_STOP; |
| } else { |
| if (!brightness) |
| led_cdev->flags |= LED_BLINK_ONESHOT_STOP; |
| } |
| } |
| |
| mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); |
| } |
| |
| static void set_brightness_delayed(struct work_struct *ws) |
| { |
| struct led_classdev *led_cdev = |
| container_of(ws, struct led_classdev, set_brightness_work); |
| |
| led_stop_software_blink(led_cdev); |
| |
| led_set_brightness_async(led_cdev, led_cdev->delayed_set_value); |
| } |
| |
| /** |
| * 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); |
| |
| if (led_cdev->flash_resume) |
| led_cdev->flash_resume(led_cdev); |
| |
| led_cdev->flags &= ~LED_SUSPENDED; |
| } |
| EXPORT_SYMBOL_GPL(led_classdev_resume); |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int led_suspend(struct device *dev) |
| { |
| 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; |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); |
| |
| static int match_name(struct device *dev, const void *data) |
| { |
| if (!dev_name(dev)) |
| return 0; |
| return !strcmp(dev_name(dev), (char *)data); |
| } |
| |
| static int led_classdev_next_name(const char *init_name, char *name, |
| size_t len) |
| { |
| unsigned int i = 0; |
| int ret = 0; |
| struct device *dev; |
| |
| strlcpy(name, init_name, len); |
| |
| while ((ret < len) && |
| (dev = class_find_device(leds_class, NULL, name, match_name))) { |
| put_device(dev); |
| ret = snprintf(name, len, "%s_%u", init_name, ++i); |
| } |
| |
| if (ret >= len) |
| return -ENOMEM; |
| |
| return i; |
| } |
| |
| /** |
| * 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) |
| { |
| char name[64]; |
| int ret; |
| |
| ret = led_classdev_next_name(led_cdev->name, name, sizeof(name)); |
| if (ret < 0) |
| return ret; |
| |
| led_cdev->dev = device_create_with_groups(leds_class, parent, 0, |
| led_cdev, led_cdev->groups, "%s", name); |
| if (IS_ERR(led_cdev->dev)) |
| return PTR_ERR(led_cdev->dev); |
| |
| if (ret) |
| dev_warn(parent, "Led %s renamed to %s due to name collision", |
| led_cdev->name, dev_name(led_cdev->dev)); |
| |
| #ifdef CONFIG_LEDS_TRIGGERS |
| init_rwsem(&led_cdev->trigger_lock); |
| #endif |
| mutex_init(&led_cdev->led_access); |
| /* 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_cdev->flags |= SET_BRIGHTNESS_ASYNC; |
| |
| led_update_brightness(led_cdev); |
| |
| INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); |
| |
| setup_timer(&led_cdev->blink_timer, led_timer_function, |
| (unsigned long)led_cdev); |
| |
| #ifdef CONFIG_LEDS_TRIGGERS |
| led_trigger_set_default(led_cdev); |
| #endif |
| |
| dev_dbg(parent, "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 |
| |
| cancel_work_sync(&led_cdev->set_brightness_work); |
| |
| /* Stop blinking */ |
| led_stop_software_blink(led_cdev); |
| led_set_brightness(led_cdev, LED_OFF); |
| |
| device_unregister(led_cdev->dev); |
| |
| down_write(&leds_list_lock); |
| list_del(&led_cdev->node); |
| up_write(&leds_list_lock); |
| |
| mutex_destroy(&led_cdev->led_access); |
| } |
| EXPORT_SYMBOL_GPL(led_classdev_unregister); |
| |
| static void devm_led_classdev_release(struct device *dev, void *res) |
| { |
| led_classdev_unregister(*(struct led_classdev **)res); |
| } |
| |
| /** |
| * devm_led_classdev_register - resource managed led_classdev_register() |
| * @parent: The device to register. |
| * @led_cdev: the led_classdev structure for this device. |
| */ |
| int devm_led_classdev_register(struct device *parent, |
| struct led_classdev *led_cdev) |
| { |
| struct led_classdev **dr; |
| int rc; |
| |
| dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL); |
| if (!dr) |
| return -ENOMEM; |
| |
| rc = led_classdev_register(parent, led_cdev); |
| if (rc) { |
| devres_free(dr); |
| return rc; |
| } |
| |
| *dr = led_cdev; |
| devres_add(parent, dr); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(devm_led_classdev_register); |
| |
| static int devm_led_classdev_match(struct device *dev, void *res, void *data) |
| { |
| struct led_cdev **p = res; |
| |
| if (WARN_ON(!p || !*p)) |
| return 0; |
| |
| return *p == data; |
| } |
| |
| /** |
| * devm_led_classdev_unregister() - resource managed led_classdev_unregister() |
| * @parent: The device to unregister. |
| * @led_cdev: the led_classdev structure for this device. |
| */ |
| void devm_led_classdev_unregister(struct device *dev, |
| struct led_classdev *led_cdev) |
| { |
| WARN_ON(devres_release(dev, |
| devm_led_classdev_release, |
| devm_led_classdev_match, led_cdev)); |
| } |
| EXPORT_SYMBOL_GPL(devm_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->pm = &leds_class_dev_pm_ops; |
| leds_class->dev_groups = led_groups; |
| 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"); |