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linux-next/include/linux/leds.h
Hans de Goede 0cb8eb30d4 leds: class: Add new optional brightness_hw_changed attribute 
Some LEDs may have their brightness level changed autonomously
(outside of kernel control) by hardware / firmware. This commit
adds support for an optional brightness_hw_changed attribute to
signal such changes to userspace (if a driver can detect them):

What:		/sys/class/leds/<led>/brightness_hw_changed
Date:		January 2017
KernelVersion:	4.11
Description:
		Last hardware set brightness level for this LED. Some LEDs
		may be changed autonomously by hardware/firmware. Only LEDs
		where this happens and the driver can detect this, will
		have this file.

		This file supports poll() to detect when the hardware
		changes the brightness.

		Reading this file will return the last brightness level set
		by the hardware, this may be different from the current
		brightness.

Drivers which want to support this, simply add LED_BRIGHT_HW_CHANGED to
their flags field and call led_classdev_notify_brightness_hw_changed()
with the hardware set brightness when they detect a hardware / firmware
triggered brightness change.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2017-01-29 19:59:42 +01:00

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/*
* Driver model for leds and led triggers
*
* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
* Copyright (C) 2005 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.
*
*/
#ifndef __LINUX_LEDS_H_INCLUDED
#define __LINUX_LEDS_H_INCLUDED
#include <linux/device.h>
#include <linux/kernfs.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
struct device;
/*
* LED Core
*/
enum led_brightness {
LED_OFF = 0,
LED_ON = 1,
LED_HALF = 127,
LED_FULL = 255,
};
struct led_classdev {
const char *name;
enum led_brightness brightness;
enum led_brightness max_brightness;
int flags;
/* Lower 16 bits reflect status */
#define LED_SUSPENDED (1 << 0)
#define LED_UNREGISTERING (1 << 1)
/* Upper 16 bits reflect control information */
#define LED_CORE_SUSPENDRESUME (1 << 16)
#define LED_SYSFS_DISABLE (1 << 17)
#define LED_DEV_CAP_FLASH (1 << 18)
#define LED_HW_PLUGGABLE (1 << 19)
#define LED_PANIC_INDICATOR (1 << 20)
#define LED_BRIGHT_HW_CHANGED (1 << 21)
/* set_brightness_work / blink_timer flags, atomic, private. */
unsigned long work_flags;
#define LED_BLINK_SW 0
#define LED_BLINK_ONESHOT 1
#define LED_BLINK_ONESHOT_STOP 2
#define LED_BLINK_INVERT 3
#define LED_BLINK_BRIGHTNESS_CHANGE 4
#define LED_BLINK_DISABLE 5
/* Set LED brightness level
* Must not sleep. Use brightness_set_blocking for drivers
* that can sleep while setting brightness.
*/
void (*brightness_set)(struct led_classdev *led_cdev,
enum led_brightness brightness);
/*
* Set LED brightness level immediately - it can block the caller for
* the time required for accessing a LED device register.
*/
int (*brightness_set_blocking)(struct led_classdev *led_cdev,
enum led_brightness brightness);
/* Get LED brightness level */
enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
/*
* Activate hardware accelerated blink, delays are in milliseconds
* and if both are zero then a sensible default should be chosen.
* The call should adjust the timings in that case and if it can't
* match the values specified exactly.
* Deactivate blinking again when the brightness is set to LED_OFF
* via the brightness_set() callback.
*/
int (*blink_set)(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off);
struct device *dev;
const struct attribute_group **groups;
struct list_head node; /* LED Device list */
const char *default_trigger; /* Trigger to use */
unsigned long blink_delay_on, blink_delay_off;
struct timer_list blink_timer;
int blink_brightness;
int new_blink_brightness;
void (*flash_resume)(struct led_classdev *led_cdev);
struct work_struct set_brightness_work;
int delayed_set_value;
#ifdef CONFIG_LEDS_TRIGGERS
/* Protects the trigger data below */
struct rw_semaphore trigger_lock;
struct led_trigger *trigger;
struct list_head trig_list;
void *trigger_data;
/* true if activated - deactivate routine uses it to do cleanup */
bool activated;
#endif
#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
int brightness_hw_changed;
struct kernfs_node *brightness_hw_changed_kn;
#endif
/* Ensures consistent access to the LED Flash Class device */
struct mutex led_access;
};
extern int led_classdev_register(struct device *parent,
struct led_classdev *led_cdev);
extern int devm_led_classdev_register(struct device *parent,
struct led_classdev *led_cdev);
extern void led_classdev_unregister(struct led_classdev *led_cdev);
extern void devm_led_classdev_unregister(struct device *parent,
struct led_classdev *led_cdev);
extern void led_classdev_suspend(struct led_classdev *led_cdev);
extern void led_classdev_resume(struct led_classdev *led_cdev);
/**
* led_blink_set - set blinking with software fallback
* @led_cdev: the LED to start blinking
* @delay_on: the time it should be on (in ms)
* @delay_off: the time it should ble off (in ms)
*
* This function makes the LED blink, attempting to use the
* hardware acceleration if possible, but falling back to
* software blinking if there is no hardware blinking or if
* the LED refuses the passed values.
*
* Note that if software blinking is active, simply calling
* led_cdev->brightness_set() will not stop the blinking,
* use led_classdev_brightness_set() instead.
*/
extern void led_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off);
/**
* led_blink_set_oneshot - do a oneshot software blink
* @led_cdev: the LED to start blinking
* @delay_on: the time it should be on (in ms)
* @delay_off: the time it should ble off (in ms)
* @invert: blink off, then on, leaving the led on
*
* This function makes the LED blink one time for delay_on +
* delay_off time, ignoring the request if another one-shot
* blink is already in progress.
*
* If invert is set, led blinks for delay_off first, then for
* delay_on and leave the led on after the on-off cycle.
*/
extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off,
int invert);
/**
* led_set_brightness - set LED brightness
* @led_cdev: the LED to set
* @brightness: the brightness to set it to
*
* Set an LED's brightness, and, if necessary, cancel the
* software blink timer that implements blinking when the
* hardware doesn't. This function is guaranteed not to sleep.
*/
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
/**
* led_set_brightness_sync - set LED brightness synchronously
* @led_cdev: the LED to set
* @brightness: the brightness to set it to
*
* Set an LED's brightness immediately. This function will block
* the caller for the time required for accessing device registers,
* and it can sleep.
*
* Returns: 0 on success or negative error value on failure
*/
extern int led_set_brightness_sync(struct led_classdev *led_cdev,
enum led_brightness value);
/**
* led_update_brightness - update LED brightness
* @led_cdev: the LED to query
*
* Get an LED's current brightness and update led_cdev->brightness
* member with the obtained value.
*
* Returns: 0 on success or negative error value on failure
*/
extern int led_update_brightness(struct led_classdev *led_cdev);
/**
* led_sysfs_disable - disable LED sysfs interface
* @led_cdev: the LED to set
*
* Disable the led_cdev's sysfs interface.
*/
extern void led_sysfs_disable(struct led_classdev *led_cdev);
/**
* led_sysfs_enable - enable LED sysfs interface
* @led_cdev: the LED to set
*
* Enable the led_cdev's sysfs interface.
*/
extern void led_sysfs_enable(struct led_classdev *led_cdev);
/**
* led_sysfs_is_disabled - check if LED sysfs interface is disabled
* @led_cdev: the LED to query
*
* Returns: true if the led_cdev's sysfs interface is disabled.
*/
static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
{
return led_cdev->flags & LED_SYSFS_DISABLE;
}
/*
* LED Triggers
*/
/* Registration functions for simple triggers */
#define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
#define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
#ifdef CONFIG_LEDS_TRIGGERS
#define TRIG_NAME_MAX 50
struct led_trigger {
/* Trigger Properties */
const char *name;
void (*activate)(struct led_classdev *led_cdev);
void (*deactivate)(struct led_classdev *led_cdev);
/* LEDs under control by this trigger (for simple triggers) */
rwlock_t leddev_list_lock;
struct list_head led_cdevs;
/* Link to next registered trigger */
struct list_head next_trig;
};
ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count);
ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
char *buf);
/* Registration functions for complex triggers */
extern int led_trigger_register(struct led_trigger *trigger);
extern void led_trigger_unregister(struct led_trigger *trigger);
extern int devm_led_trigger_register(struct device *dev,
struct led_trigger *trigger);
extern void led_trigger_register_simple(const char *name,
struct led_trigger **trigger);
extern void led_trigger_unregister_simple(struct led_trigger *trigger);
extern void led_trigger_event(struct led_trigger *trigger,
enum led_brightness event);
extern void led_trigger_blink(struct led_trigger *trigger,
unsigned long *delay_on,
unsigned long *delay_off);
extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
unsigned long *delay_on,
unsigned long *delay_off,
int invert);
extern void led_trigger_set_default(struct led_classdev *led_cdev);
extern void led_trigger_set(struct led_classdev *led_cdev,
struct led_trigger *trigger);
extern void led_trigger_remove(struct led_classdev *led_cdev);
static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
{
return led_cdev->trigger_data;
}
/**
* led_trigger_rename_static - rename a trigger
* @name: the new trigger name
* @trig: the LED trigger to rename
*
* Change a LED trigger name by copying the string passed in
* name into current trigger name, which MUST be large
* enough for the new string.
*
* Note that name must NOT point to the same string used
* during LED registration, as that could lead to races.
*
* This is meant to be used on triggers with statically
* allocated name.
*/
extern void led_trigger_rename_static(const char *name,
struct led_trigger *trig);
#else
/* Trigger has no members */
struct led_trigger {};
/* Trigger inline empty functions */
static inline void led_trigger_register_simple(const char *name,
struct led_trigger **trigger) {}
static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
static inline void led_trigger_event(struct led_trigger *trigger,
enum led_brightness event) {}
static inline void led_trigger_blink(struct led_trigger *trigger,
unsigned long *delay_on,
unsigned long *delay_off) {}
static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
unsigned long *delay_on,
unsigned long *delay_off,
int invert) {}
static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
static inline void led_trigger_set(struct led_classdev *led_cdev,
struct led_trigger *trigger) {}
static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
{
return NULL;
}
#endif /* CONFIG_LEDS_TRIGGERS */
/* Trigger specific functions */
#ifdef CONFIG_LEDS_TRIGGER_DISK
extern void ledtrig_disk_activity(void);
#else
static inline void ledtrig_disk_activity(void) {}
#endif
#ifdef CONFIG_LEDS_TRIGGER_MTD
extern void ledtrig_mtd_activity(void);
#else
static inline void ledtrig_mtd_activity(void) {}
#endif
#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
extern void ledtrig_flash_ctrl(bool on);
extern void ledtrig_torch_ctrl(bool on);
#else
static inline void ledtrig_flash_ctrl(bool on) {}
static inline void ledtrig_torch_ctrl(bool on) {}
#endif
/*
* Generic LED platform data for describing LED names and default triggers.
*/
struct led_info {
const char *name;
const char *default_trigger;
int flags;
};
struct led_platform_data {
int num_leds;
struct led_info *leds;
};
struct gpio_desc;
typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
unsigned long *delay_on,
unsigned long *delay_off);
/* For the leds-gpio driver */
struct gpio_led {
const char *name;
const char *default_trigger;
unsigned gpio;
unsigned active_low : 1;
unsigned retain_state_suspended : 1;
unsigned panic_indicator : 1;
unsigned default_state : 2;
/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
struct gpio_desc *gpiod;
};
#define LEDS_GPIO_DEFSTATE_OFF 0
#define LEDS_GPIO_DEFSTATE_ON 1
#define LEDS_GPIO_DEFSTATE_KEEP 2
struct gpio_led_platform_data {
int num_leds;
const struct gpio_led *leds;
#define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
#define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
#define GPIO_LED_BLINK 2 /* Please, blink */
gpio_blink_set_t gpio_blink_set;
};
#ifdef CONFIG_NEW_LEDS
struct platform_device *gpio_led_register_device(
int id, const struct gpio_led_platform_data *pdata);
#else
static inline struct platform_device *gpio_led_register_device(
int id, const struct gpio_led_platform_data *pdata)
{
return 0;
}
#endif
enum cpu_led_event {
CPU_LED_IDLE_START, /* CPU enters idle */
CPU_LED_IDLE_END, /* CPU idle ends */
CPU_LED_START, /* Machine starts, especially resume */
CPU_LED_STOP, /* Machine stops, especially suspend */
CPU_LED_HALTED, /* Machine shutdown */
};
#ifdef CONFIG_LEDS_TRIGGER_CPU
extern void ledtrig_cpu(enum cpu_led_event evt);
#else
static inline void ledtrig_cpu(enum cpu_led_event evt)
{
return;
}
#endif
#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
extern void led_classdev_notify_brightness_hw_changed(
struct led_classdev *led_cdev, enum led_brightness brightness);
#else
static inline void led_classdev_notify_brightness_hw_changed(
struct led_classdev *led_cdev, enum led_brightness brightness) { }
#endif
#endif /* __LINUX_LEDS_H_INCLUDED */
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