text: /*
   * 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;
  struct led_pattern;
  /*
   * 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		BIT(0)
  #define LED_UNREGISTERING	BIT(1)
  	/* Upper 16 bits reflect control information */
  #define LED_CORE_SUSPENDRESUME	BIT(16)
  #define LED_SYSFS_DISABLE	BIT(17)
  #define LED_DEV_CAP_FLASH	BIT(18)
  #define LED_HW_PLUGGABLE	BIT(19)
  #define LED_PANIC_INDICATOR	BIT(20)
  #define LED_BRIGHT_HW_CHANGED	BIT(21)
  #define LED_RETAIN_AT_SHUTDOWN	BIT(22)
  #define LED_INIT_DEFAULT_TRIGGER BIT(23)
  
  	/* 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);
  
  	int (*pattern_set)(struct led_classdev *led_cdev,
  			   struct led_pattern *pattern, u32 len, int repeat);
  	int (*pattern_clear)(struct led_classdev *led_cdev);
  
  	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 of_led_classdev_register(struct device *parent,
  				    struct device_node *np,
  				    struct led_classdev *led_cdev);
  #define led_classdev_register(parent, led_cdev)				\
  	of_led_classdev_register(parent, NULL, led_cdev)
  extern int devm_of_led_classdev_register(struct device *parent,
  					 struct device_node *np,
  					 struct led_classdev *led_cdev);
  #define devm_led_classdev_register(parent, led_cdev)			\
  	devm_of_led_classdev_register(parent, NULL, 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_get_default_pattern - return default pattern
   *
   * @led_cdev: the LED to get default pattern for
   * @size:     pointer for storing the number of elements in returned array,
   *            modified only if return != NULL
   *
   * Return:    Allocated array of integers with default pattern from device tree
   *            or NULL.  Caller is responsible for kfree().
   */
  extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
  				    unsigned int *size);
  
  /**
   * 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;
  	int		(*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;
  
  	const struct attribute_group **groups;
  };
  
  /*
   * Currently the attributes in struct led_trigger::groups are added directly to
   * the LED device. As this might change in the future, the following
   * macros abstract getting the LED device and its trigger_data from the dev
   * parameter passed to the attribute accessor functions.
   */
  #define led_trigger_get_led(dev)	((struct led_classdev *)dev_get_drvdata((dev)))
  #define led_trigger_get_drvdata(dev)	(led_get_trigger_data(led_trigger_get_led(dev)))
  
  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 int 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_set_trigger_data(struct led_classdev *led_cdev,
  					void *trigger_data)
  {
  	led_cdev->trigger_data = trigger_data;
  }
  
  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);
  
  #define module_led_trigger(__led_trigger) \
  	module_driver(__led_trigger, led_trigger_register, \
  		      led_trigger_unregister)
  
  #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 int led_trigger_set(struct led_classdev *led_cdev,
  				  struct led_trigger *trigger)
  {
  	return 0;
  }
  
  static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
  static inline void led_set_trigger_data(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(bool write);
  #else
  static inline void ledtrig_disk_activity(bool write) {}
  #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;
  	unsigned	retain_state_shutdown : 1;
  	/* 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
  
  /**
   * struct led_pattern - pattern interval settings
   * @delta_t: pattern interval delay, in milliseconds
   * @brightness: pattern interval brightness
   */
  struct led_pattern {
  	u32 delta_t;
  	int brightness;
  };
  
  enum led_audio {
  	LED_AUDIO_MUTE,		/* master mute LED */
  	LED_AUDIO_MICMUTE,	/* mic mute LED */
  	NUM_AUDIO_LEDS
  };
  
  #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
  enum led_brightness ledtrig_audio_get(enum led_audio type);
  void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
  #else
  static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
  {
  	return LED_OFF;
  }
  static inline void ledtrig_audio_set(enum led_audio type,
  				     enum led_brightness state)
  {
  }
  #endif
  
  #endif		/* __LINUX_LEDS_H_INCLUDED */
  