diff options
Diffstat (limited to 'drivers/leds/led-class.c')
| -rw-r--r-- | drivers/leds/led-class.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c new file mode 100644 index 000000000..4e63dd2bf --- /dev/null +++ b/drivers/leds/led-class.c @@ -0,0 +1,435 @@ +/* + * 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 <uapi/linux/uleds.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, +}; + +#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED +static ssize_t brightness_hw_changed_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + if (led_cdev->brightness_hw_changed == -1) + return -ENODATA; + + return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed); +} + +static DEVICE_ATTR_RO(brightness_hw_changed); + +static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) +{ + struct device *dev = led_cdev->dev; + int ret; + + ret = device_create_file(dev, &dev_attr_brightness_hw_changed); + if (ret) { + dev_err(dev, "Error creating brightness_hw_changed\n"); + return ret; + } + + led_cdev->brightness_hw_changed_kn = + sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed"); + if (!led_cdev->brightness_hw_changed_kn) { + dev_err(dev, "Error getting brightness_hw_changed kn\n"); + device_remove_file(dev, &dev_attr_brightness_hw_changed); + return -ENXIO; + } + + return 0; +} + +static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) +{ + sysfs_put(led_cdev->brightness_hw_changed_kn); + device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed); +} + +void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + if (WARN_ON(!led_cdev->brightness_hw_changed_kn)) + return; + + led_cdev->brightness_hw_changed = brightness; + sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn); +} +EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed); +#else +static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) +{ + return 0; +} +static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) +{ +} +#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_set_brightness_nopm(led_cdev, 0); + flush_work(&led_cdev->set_brightness_work); +} +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_set_brightness_nopm(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; +} + +/** + * of_led_classdev_register - register a new object of led_classdev class. + * + * @parent: parent of LED device + * @led_cdev: the led_classdev structure for this device. + * @np: DT node describing this LED + */ +int of_led_classdev_register(struct device *parent, struct device_node *np, + struct led_classdev *led_cdev) +{ + char name[LED_MAX_NAME_SIZE]; + int ret; + + ret = led_classdev_next_name(led_cdev->name, name, sizeof(name)); + if (ret < 0) + return ret; + + mutex_init(&led_cdev->led_access); + mutex_lock(&led_cdev->led_access); + led_cdev->dev = device_create_with_groups(leds_class, parent, 0, + led_cdev, led_cdev->groups, "%s", name); + if (IS_ERR(led_cdev->dev)) { + mutex_unlock(&led_cdev->led_access); + return PTR_ERR(led_cdev->dev); + } + led_cdev->dev->of_node = np; + + if (ret) + dev_warn(parent, "Led %s renamed to %s due to name collision", + led_cdev->name, dev_name(led_cdev->dev)); + + if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) { + ret = led_add_brightness_hw_changed(led_cdev); + if (ret) { + device_unregister(led_cdev->dev); + mutex_unlock(&led_cdev->led_access); + return ret; + } + } + + led_cdev->work_flags = 0; +#ifdef CONFIG_LEDS_TRIGGERS + init_rwsem(&led_cdev->trigger_lock); +#endif +#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED + led_cdev->brightness_hw_changed = -1; +#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); + + led_init_core(led_cdev); + +#ifdef CONFIG_LEDS_TRIGGERS + led_trigger_set_default(led_cdev); +#endif + + mutex_unlock(&led_cdev->led_access); + + dev_dbg(parent, "Registered led device: %s\n", + led_cdev->name); + + return 0; +} +EXPORT_SYMBOL_GPL(of_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 + + led_cdev->flags |= LED_UNREGISTERING; + + /* Stop blinking */ + led_stop_software_blink(led_cdev); + + led_set_brightness(led_cdev, LED_OFF); + + flush_work(&led_cdev->set_brightness_work); + + if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) + led_remove_brightness_hw_changed(led_cdev); + + 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_of_led_classdev_register - resource managed led_classdev_register() + * + * @parent: parent of LED device + * @led_cdev: the led_classdev structure for this device. + */ +int devm_of_led_classdev_register(struct device *parent, + struct device_node *np, + 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 = of_led_classdev_register(parent, np, led_cdev); + if (rc) { + devres_free(dr); + return rc; + } + + *dr = led_cdev; + devres_add(parent, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_of_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"); |