429 lines
10 KiB
C
429 lines
10 KiB
C
/*
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* LED Class Core
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*
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* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
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* Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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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/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 "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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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 DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
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static struct attribute *led_trigger_attrs[] = {
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&dev_attr_trigger.attr,
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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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.attrs = led_trigger_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,
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enum led_brightness 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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}
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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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static int match_name(struct device *dev, const void *data)
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{
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if (!dev_name(dev))
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return 0;
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return !strcmp(dev_name(dev), (char *)data);
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}
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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(leds_class, NULL, name, match_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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* of_led_classdev_register - register a new object of led_classdev class.
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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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* @np: DT node describing this LED
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*/
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int of_led_classdev_register(struct device *parent, struct device_node *np,
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struct led_classdev *led_cdev)
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{
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char name[LED_MAX_NAME_SIZE];
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int ret;
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ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
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if (ret < 0)
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return ret;
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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", name);
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if (IS_ERR(led_cdev->dev))
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return PTR_ERR(led_cdev->dev);
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led_cdev->dev->of_node = np;
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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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led_cdev->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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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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mutex_init(&led_cdev->led_access);
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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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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(of_led_classdev_register);
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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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#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_of_led_classdev_register - resource managed led_classdev_register()
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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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*/
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int devm_of_led_classdev_register(struct device *parent,
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struct device_node *np,
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struct led_classdev *led_cdev)
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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 = of_led_classdev_register(parent, np, led_cdev);
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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_of_led_classdev_register);
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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_cdev **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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