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548 lines
13 KiB
548 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* LED Class Core |
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* |
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* Copyright (C) 2005 John Lenz <[email protected]> |
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* Copyright (C) 2005-2007 Richard Purdie <[email protected]> |
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*/ |
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#include <linux/ctype.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/leds.h> |
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#include <linux/list.h> |
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#include <linux/module.h> |
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#include <linux/property.h> |
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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#include <linux/timer.h> |
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#include <uapi/linux/uleds.h> |
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#include <linux/of.h> |
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#include "leds.h" |
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static struct class *leds_class; |
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static ssize_t brightness_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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/* no lock needed for this */ |
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led_update_brightness(led_cdev); |
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return sprintf(buf, "%u\n", led_cdev->brightness); |
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} |
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static ssize_t brightness_store(struct device *dev, |
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struct device_attribute *attr, const char *buf, size_t size) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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unsigned long state; |
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ssize_t ret; |
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mutex_lock(&led_cdev->led_access); |
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if (led_sysfs_is_disabled(led_cdev)) { |
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ret = -EBUSY; |
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goto unlock; |
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} |
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ret = kstrtoul(buf, 10, &state); |
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if (ret) |
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goto unlock; |
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if (state == LED_OFF) |
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led_trigger_remove(led_cdev); |
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led_set_brightness(led_cdev, state); |
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flush_work(&led_cdev->set_brightness_work); |
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ret = size; |
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unlock: |
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mutex_unlock(&led_cdev->led_access); |
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return ret; |
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} |
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static DEVICE_ATTR_RW(brightness); |
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static ssize_t max_brightness_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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return sprintf(buf, "%u\n", led_cdev->max_brightness); |
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} |
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static DEVICE_ATTR_RO(max_brightness); |
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#ifdef CONFIG_LEDS_TRIGGERS |
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static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0); |
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static struct bin_attribute *led_trigger_bin_attrs[] = { |
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&bin_attr_trigger, |
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NULL, |
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}; |
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static const struct attribute_group led_trigger_group = { |
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.bin_attrs = led_trigger_bin_attrs, |
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}; |
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#endif |
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static struct attribute *led_class_attrs[] = { |
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&dev_attr_brightness.attr, |
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&dev_attr_max_brightness.attr, |
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NULL, |
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}; |
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static const struct attribute_group led_group = { |
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.attrs = led_class_attrs, |
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}; |
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static const struct attribute_group *led_groups[] = { |
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&led_group, |
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#ifdef CONFIG_LEDS_TRIGGERS |
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&led_trigger_group, |
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#endif |
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NULL, |
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}; |
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#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED |
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static ssize_t brightness_hw_changed_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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if (led_cdev->brightness_hw_changed == -1) |
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return -ENODATA; |
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return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed); |
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} |
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static DEVICE_ATTR_RO(brightness_hw_changed); |
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static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) |
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{ |
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struct device *dev = led_cdev->dev; |
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int ret; |
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ret = device_create_file(dev, &dev_attr_brightness_hw_changed); |
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if (ret) { |
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dev_err(dev, "Error creating brightness_hw_changed\n"); |
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return ret; |
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} |
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led_cdev->brightness_hw_changed_kn = |
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sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed"); |
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if (!led_cdev->brightness_hw_changed_kn) { |
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dev_err(dev, "Error getting brightness_hw_changed kn\n"); |
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device_remove_file(dev, &dev_attr_brightness_hw_changed); |
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return -ENXIO; |
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} |
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return 0; |
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} |
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static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) |
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{ |
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sysfs_put(led_cdev->brightness_hw_changed_kn); |
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device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed); |
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} |
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void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness) |
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{ |
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if (WARN_ON(!led_cdev->brightness_hw_changed_kn)) |
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return; |
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led_cdev->brightness_hw_changed = brightness; |
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sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn); |
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} |
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EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed); |
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#else |
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static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) |
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{ |
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return 0; |
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} |
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static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) |
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{ |
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} |
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#endif |
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/** |
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* led_classdev_suspend - suspend an led_classdev. |
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* @led_cdev: the led_classdev to suspend. |
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*/ |
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void led_classdev_suspend(struct led_classdev *led_cdev) |
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{ |
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led_cdev->flags |= LED_SUSPENDED; |
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led_set_brightness_nopm(led_cdev, 0); |
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flush_work(&led_cdev->set_brightness_work); |
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} |
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EXPORT_SYMBOL_GPL(led_classdev_suspend); |
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/** |
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* led_classdev_resume - resume an led_classdev. |
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* @led_cdev: the led_classdev to resume. |
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*/ |
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void led_classdev_resume(struct led_classdev *led_cdev) |
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{ |
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led_set_brightness_nopm(led_cdev, led_cdev->brightness); |
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if (led_cdev->flash_resume) |
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led_cdev->flash_resume(led_cdev); |
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led_cdev->flags &= ~LED_SUSPENDED; |
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} |
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EXPORT_SYMBOL_GPL(led_classdev_resume); |
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#ifdef CONFIG_PM_SLEEP |
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static int led_suspend(struct device *dev) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
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led_classdev_suspend(led_cdev); |
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return 0; |
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} |
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static int led_resume(struct device *dev) |
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{ |
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struct led_classdev *led_cdev = dev_get_drvdata(dev); |
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if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
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led_classdev_resume(led_cdev); |
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return 0; |
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} |
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#endif |
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static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); |
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/** |
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* of_led_get() - request a LED device via the LED framework |
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* @np: device node to get the LED device from |
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* @index: the index of the LED |
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* |
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* Returns the LED device parsed from the phandle specified in the "leds" |
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* property of a device tree node or a negative error-code on failure. |
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*/ |
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struct led_classdev *of_led_get(struct device_node *np, int index) |
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{ |
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struct device *led_dev; |
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struct led_classdev *led_cdev; |
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struct device_node *led_node; |
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led_node = of_parse_phandle(np, "leds", index); |
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if (!led_node) |
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return ERR_PTR(-ENOENT); |
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led_dev = class_find_device_by_of_node(leds_class, led_node); |
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of_node_put(led_node); |
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if (!led_dev) |
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return ERR_PTR(-EPROBE_DEFER); |
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led_cdev = dev_get_drvdata(led_dev); |
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if (!try_module_get(led_cdev->dev->parent->driver->owner)) |
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return ERR_PTR(-ENODEV); |
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return led_cdev; |
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} |
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EXPORT_SYMBOL_GPL(of_led_get); |
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/** |
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* led_put() - release a LED device |
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* @led_cdev: LED device |
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*/ |
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void led_put(struct led_classdev *led_cdev) |
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{ |
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module_put(led_cdev->dev->parent->driver->owner); |
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} |
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EXPORT_SYMBOL_GPL(led_put); |
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static void devm_led_release(struct device *dev, void *res) |
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{ |
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struct led_classdev **p = res; |
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led_put(*p); |
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} |
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/** |
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* devm_of_led_get - Resource-managed request of a LED device |
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* @dev: LED consumer |
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* @index: index of the LED to obtain in the consumer |
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* |
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* The device node of the device is parse to find the request LED device. |
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* The LED device returned from this function is automatically released |
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* on driver detach. |
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* |
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* @return a pointer to a LED device or ERR_PTR(errno) on failure. |
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*/ |
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struct led_classdev *__must_check devm_of_led_get(struct device *dev, |
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int index) |
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{ |
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struct led_classdev *led; |
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struct led_classdev **dr; |
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if (!dev) |
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return ERR_PTR(-EINVAL); |
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/* Not using device tree? */ |
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if (!IS_ENABLED(CONFIG_OF) || !dev->of_node) |
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return ERR_PTR(-ENOTSUPP); |
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led = of_led_get(dev->of_node, index); |
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if (IS_ERR(led)) |
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return led; |
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dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), |
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GFP_KERNEL); |
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if (!dr) { |
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led_put(led); |
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return ERR_PTR(-ENOMEM); |
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} |
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*dr = led; |
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devres_add(dev, dr); |
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return led; |
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} |
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EXPORT_SYMBOL_GPL(devm_of_led_get); |
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static int led_classdev_next_name(const char *init_name, char *name, |
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size_t len) |
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{ |
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unsigned int i = 0; |
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int ret = 0; |
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struct device *dev; |
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strlcpy(name, init_name, len); |
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while ((ret < len) && |
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(dev = class_find_device_by_name(leds_class, name))) { |
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put_device(dev); |
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ret = snprintf(name, len, "%s_%u", init_name, ++i); |
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} |
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if (ret >= len) |
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return -ENOMEM; |
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return i; |
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} |
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/** |
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* led_classdev_register_ext - register a new object of led_classdev class |
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* with init data. |
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* |
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* @parent: parent of LED device |
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* @led_cdev: the led_classdev structure for this device. |
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* @init_data: LED class device initialization data |
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*/ |
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int led_classdev_register_ext(struct device *parent, |
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struct led_classdev *led_cdev, |
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struct led_init_data *init_data) |
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{ |
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char composed_name[LED_MAX_NAME_SIZE]; |
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char final_name[LED_MAX_NAME_SIZE]; |
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const char *proposed_name = composed_name; |
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int ret; |
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if (init_data) { |
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if (init_data->devname_mandatory && !init_data->devicename) { |
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dev_err(parent, "Mandatory device name is missing"); |
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return -EINVAL; |
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} |
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ret = led_compose_name(parent, init_data, composed_name); |
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if (ret < 0) |
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return ret; |
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if (init_data->fwnode) |
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fwnode_property_read_string(init_data->fwnode, |
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"linux,default-trigger", |
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&led_cdev->default_trigger); |
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} else { |
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proposed_name = led_cdev->name; |
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} |
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ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name)); |
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if (ret < 0) |
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return ret; |
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mutex_init(&led_cdev->led_access); |
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mutex_lock(&led_cdev->led_access); |
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led_cdev->dev = device_create_with_groups(leds_class, parent, 0, |
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led_cdev, led_cdev->groups, "%s", final_name); |
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if (IS_ERR(led_cdev->dev)) { |
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mutex_unlock(&led_cdev->led_access); |
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return PTR_ERR(led_cdev->dev); |
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} |
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if (init_data && init_data->fwnode) { |
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led_cdev->dev->fwnode = init_data->fwnode; |
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led_cdev->dev->of_node = to_of_node(init_data->fwnode); |
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} |
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if (ret) |
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dev_warn(parent, "Led %s renamed to %s due to name collision", |
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proposed_name, dev_name(led_cdev->dev)); |
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if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) { |
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ret = led_add_brightness_hw_changed(led_cdev); |
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if (ret) { |
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device_unregister(led_cdev->dev); |
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led_cdev->dev = NULL; |
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mutex_unlock(&led_cdev->led_access); |
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return ret; |
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} |
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} |
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led_cdev->work_flags = 0; |
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#ifdef CONFIG_LEDS_TRIGGERS |
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init_rwsem(&led_cdev->trigger_lock); |
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#endif |
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#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED |
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led_cdev->brightness_hw_changed = -1; |
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#endif |
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/* add to the list of leds */ |
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down_write(&leds_list_lock); |
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list_add_tail(&led_cdev->node, &leds_list); |
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up_write(&leds_list_lock); |
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if (!led_cdev->max_brightness) |
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led_cdev->max_brightness = LED_FULL; |
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led_update_brightness(led_cdev); |
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led_init_core(led_cdev); |
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#ifdef CONFIG_LEDS_TRIGGERS |
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led_trigger_set_default(led_cdev); |
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#endif |
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mutex_unlock(&led_cdev->led_access); |
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dev_dbg(parent, "Registered led device: %s\n", |
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led_cdev->name); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(led_classdev_register_ext); |
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/** |
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* led_classdev_unregister - unregisters a object of led_properties class. |
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* @led_cdev: the led device to unregister |
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* |
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* Unregisters a previously registered via led_classdev_register object. |
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*/ |
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void led_classdev_unregister(struct led_classdev *led_cdev) |
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{ |
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if (IS_ERR_OR_NULL(led_cdev->dev)) |
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return; |
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#ifdef CONFIG_LEDS_TRIGGERS |
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down_write(&led_cdev->trigger_lock); |
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if (led_cdev->trigger) |
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led_trigger_set(led_cdev, NULL); |
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up_write(&led_cdev->trigger_lock); |
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#endif |
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led_cdev->flags |= LED_UNREGISTERING; |
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/* Stop blinking */ |
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led_stop_software_blink(led_cdev); |
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led_set_brightness(led_cdev, LED_OFF); |
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flush_work(&led_cdev->set_brightness_work); |
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if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) |
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led_remove_brightness_hw_changed(led_cdev); |
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device_unregister(led_cdev->dev); |
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down_write(&leds_list_lock); |
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list_del(&led_cdev->node); |
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up_write(&leds_list_lock); |
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mutex_destroy(&led_cdev->led_access); |
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} |
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EXPORT_SYMBOL_GPL(led_classdev_unregister); |
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static void devm_led_classdev_release(struct device *dev, void *res) |
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{ |
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led_classdev_unregister(*(struct led_classdev **)res); |
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} |
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/** |
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* devm_led_classdev_register_ext - resource managed led_classdev_register_ext() |
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* |
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* @parent: parent of LED device |
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* @led_cdev: the led_classdev structure for this device. |
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* @init_data: LED class device initialization data |
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*/ |
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int devm_led_classdev_register_ext(struct device *parent, |
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struct led_classdev *led_cdev, |
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struct led_init_data *init_data) |
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{ |
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struct led_classdev **dr; |
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int rc; |
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dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL); |
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if (!dr) |
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return -ENOMEM; |
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rc = led_classdev_register_ext(parent, led_cdev, init_data); |
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if (rc) { |
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devres_free(dr); |
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return rc; |
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} |
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*dr = led_cdev; |
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devres_add(parent, dr); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext); |
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static int devm_led_classdev_match(struct device *dev, void *res, void *data) |
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{ |
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struct led_classdev **p = res; |
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if (WARN_ON(!p || !*p)) |
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return 0; |
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return *p == data; |
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} |
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/** |
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* devm_led_classdev_unregister() - resource managed led_classdev_unregister() |
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* @parent: The device to unregister. |
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* @led_cdev: the led_classdev structure for this device. |
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*/ |
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void devm_led_classdev_unregister(struct device *dev, |
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struct led_classdev *led_cdev) |
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{ |
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WARN_ON(devres_release(dev, |
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devm_led_classdev_release, |
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devm_led_classdev_match, led_cdev)); |
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} |
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EXPORT_SYMBOL_GPL(devm_led_classdev_unregister); |
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static int __init leds_init(void) |
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{ |
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leds_class = class_create(THIS_MODULE, "leds"); |
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if (IS_ERR(leds_class)) |
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return PTR_ERR(leds_class); |
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leds_class->pm = &leds_class_dev_pm_ops; |
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leds_class->dev_groups = led_groups; |
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return 0; |
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} |
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static void __exit leds_exit(void) |
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{ |
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class_destroy(leds_class); |
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} |
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subsys_initcall(leds_init); |
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module_exit(leds_exit); |
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MODULE_AUTHOR("John Lenz, Richard Purdie"); |
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MODULE_LICENSE("GPL"); |
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MODULE_DESCRIPTION("LED Class Interface");
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