/*
 * 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           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)

        /* 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 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_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(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

#endif          /* __LINUX_LEDS_H_INCLUDED */