// SPDX-License-Identifier: GPL-2.0-only /* * LED Class Core * * Copyright (C) 2005 John Lenz * Copyright (C) 2005-2007 Richard Purdie */ #include #include #include #include #include #include #include #include #include #include #include #include #include #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); flush_work(&led_cdev->set_brightness_work); 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); } 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 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_by_name(leds_class, name))) { put_device(dev); ret = snprintf(name, len, "%s_%u", init_name, ++i); } if (ret >= len) return -ENOMEM; return i; } /** * led_classdev_register_ext - register a new object of led_classdev class * with init data. * * @parent: parent of LED device * @led_cdev: the led_classdev structure for this device. * @init_data: LED class device initialization data */ int led_classdev_register_ext(struct device *parent, struct led_classdev *led_cdev, struct led_init_data *init_data) { char composed_name[LED_MAX_NAME_SIZE]; char final_name[LED_MAX_NAME_SIZE]; const char *proposed_name = composed_name; int ret; if (init_data) { if (init_data->devname_mandatory && !init_data->devicename) { dev_err(parent, "Mandatory device name is missing"); return -EINVAL; } ret = led_compose_name(parent, init_data, composed_name); if (ret < 0) return ret; } else { proposed_name = led_cdev->name; } ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_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", final_name); if (IS_ERR(led_cdev->dev)) { mutex_unlock(&led_cdev->led_access); return PTR_ERR(led_cdev->dev); } if (init_data && init_data->fwnode) led_cdev->dev->fwnode = init_data->fwnode; 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); led_cdev->dev = NULL; 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(led_classdev_register_ext); /** * 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) { if (IS_ERR_OR_NULL(led_cdev->dev)) return; #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_led_classdev_register_ext - resource managed led_classdev_register_ext() * * @parent: parent of LED device * @led_cdev: the led_classdev structure for this device. * @init_data: LED class device initialization data */ int devm_led_classdev_register_ext(struct device *parent, struct led_classdev *led_cdev, struct led_init_data *init_data) { 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_ext(parent, led_cdev, init_data); if (rc) { devres_free(dr); return rc; } *dr = led_cdev; devres_add(parent, dr); return 0; } EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext); 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");