/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Remote Controller core raw events header
 *
 * Copyright (C) 2010 by Mauro Carvalho Chehab
 */

#ifndef _RC_CORE_PRIV
#define _RC_CORE_PRIV

#define RC_DEV_MAX              256
/* Define the max number of pulse/space transitions to buffer */
#define MAX_IR_EVENT_SIZE       512

#include <linux/slab.h>
#include <uapi/linux/bpf.h>
#include <media/rc-core.h>

/**
 * rc_open - Opens a RC device
 *
 * @rdev: pointer to struct rc_dev.
 */
int rc_open(struct rc_dev *rdev);

/**
 * rc_close - Closes a RC device
 *
 * @rdev: pointer to struct rc_dev.
 */
void rc_close(struct rc_dev *rdev);

struct ir_raw_handler {
        struct list_head list;

        u64 protocols; /* which are handled by this handler */
        int (*decode)(struct rc_dev *dev, struct ir_raw_event event);
        int (*encode)(enum rc_proto protocol, u32 scancode,
                      struct ir_raw_event *events, unsigned int max);
        u32 carrier;
        u32 min_timeout;

        /* These two should only be used by the mce kbd decoder */
        int (*raw_register)(struct rc_dev *dev);
        int (*raw_unregister)(struct rc_dev *dev);
};

struct ir_raw_event_ctrl {
        struct list_head                list;           /* to keep track of raw clients */
        struct task_struct              *thread;
        /* fifo for the pulse/space durations */
        DECLARE_KFIFO(kfifo, struct ir_raw_event, MAX_IR_EVENT_SIZE);
        ktime_t                         last_event;     /* when last event occurred */
        struct rc_dev                   *dev;           /* pointer to the parent rc_dev */
        /* handle delayed ir_raw_event_store_edge processing */
        spinlock_t                      edge_spinlock;
        struct timer_list               edge_handle;

        /* raw decoder state follows */
        struct ir_raw_event prev_ev;
        struct ir_raw_event this_ev;

#ifdef CONFIG_BPF_LIRC_MODE2
        u32                             bpf_sample;
        struct bpf_prog_array __rcu     *progs;
#endif
#if IS_ENABLED(CONFIG_IR_NEC_DECODER)
        struct nec_dec {
                int state;
                unsigned count;
                u32 bits;
                bool is_nec_x;
                bool necx_repeat;
        } nec;
#endif
#if IS_ENABLED(CONFIG_IR_RC5_DECODER)
        struct rc5_dec {
                int state;
                u32 bits;
                unsigned count;
                bool is_rc5x;
        } rc5;
#endif
#if IS_ENABLED(CONFIG_IR_RC6_DECODER)
        struct rc6_dec {
                int state;
                u8 header;
                bool toggle;
                u32 body;
                unsigned count;
                unsigned wanted_bits;
        } rc6;
#endif
#if IS_ENABLED(CONFIG_IR_SONY_DECODER)
        struct sony_dec {
                int state;
                u32 bits;
                unsigned count;
        } sony;
#endif
#if IS_ENABLED(CONFIG_IR_JVC_DECODER)
        struct jvc_dec {
                int state;
                u16 bits;
                u16 old_bits;
                unsigned count;
                bool first;
                bool toggle;
        } jvc;
#endif
#if IS_ENABLED(CONFIG_IR_SANYO_DECODER)
        struct sanyo_dec {
                int state;
                unsigned count;
                u64 bits;
        } sanyo;
#endif
#if IS_ENABLED(CONFIG_IR_SHARP_DECODER)
        struct sharp_dec {
                int state;
                unsigned count;
                u32 bits;
                unsigned int pulse_len;
        } sharp;
#endif
#if IS_ENABLED(CONFIG_IR_MCE_KBD_DECODER)
        struct mce_kbd_dec {
                /* locks key up timer */
                spinlock_t keylock;
                int state;
                struct timer_list rx_timeout;
                u8 header;
                u32 body;
                unsigned count;
                unsigned wanted_bits;
        } mce_kbd;
#endif
#if IS_ENABLED(CONFIG_IR_XMP_DECODER)
        struct xmp_dec {
                int state;
                unsigned count;
                u32 durations[16];
        } xmp;
#endif
#if IS_ENABLED(CONFIG_IR_IMON_DECODER)
        struct imon_dec {
                int state;
                int count;
                int last_chk;
                unsigned int bits;
                bool stick_keyboard;
        } imon;
#endif
#if IS_ENABLED(CONFIG_IR_RCMM_DECODER)
        struct rcmm_dec {
                int state;
                unsigned int count;
                u32 bits;
        } rcmm;
#endif
};

/* Mutex for locking raw IR processing and handler change */
extern struct mutex ir_raw_handler_lock;

/* macros for IR decoders */
static inline bool geq_margin(unsigned d1, unsigned d2, unsigned margin)
{
        return d1 > (d2 - margin);
}

static inline bool eq_margin(unsigned d1, unsigned d2, unsigned margin)
{
        return ((d1 > (d2 - margin)) && (d1 < (d2 + margin)));
}

static inline bool is_transition(struct ir_raw_event *x, struct ir_raw_event *y)
{
        return x->pulse != y->pulse;
}

static inline void decrease_duration(struct ir_raw_event *ev, unsigned duration)
{
        if (duration > ev->duration)
                ev->duration = 0;
        else
                ev->duration -= duration;
}

/* Returns true if event is normal pulse/space event */
static inline bool is_timing_event(struct ir_raw_event ev)
{
        return !ev.carrier_report && !ev.overflow;
}

#define TO_STR(is_pulse)                ((is_pulse) ? "pulse" : "space")

/* functions for IR encoders */
bool rc_validate_scancode(enum rc_proto proto, u32 scancode);

static inline void init_ir_raw_event_duration(struct ir_raw_event *ev,
                                              unsigned int pulse,
                                              u32 duration)
{
        *ev = (struct ir_raw_event) {
                .duration = duration,
                .pulse = pulse
        };
}

/**
 * struct ir_raw_timings_manchester - Manchester coding timings
 * @leader_pulse:       duration of leader pulse (if any) 0 if continuing
 *                      existing signal
 * @leader_space:       duration of leader space (if any)
 * @clock:              duration of each pulse/space in ns
 * @invert:             if set clock logic is inverted
 *                      (0 = space + pulse, 1 = pulse + space)
 * @trailer_space:      duration of trailer space in ns
 */
struct ir_raw_timings_manchester {
        unsigned int leader_pulse;
        unsigned int leader_space;
        unsigned int clock;
        unsigned int invert:1;
        unsigned int trailer_space;
};

int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max,
                          const struct ir_raw_timings_manchester *timings,
                          unsigned int n, u64 data);

/**
 * ir_raw_gen_pulse_space() - generate pulse and space raw events.
 * @ev:                 Pointer to pointer to next free raw event.
 *                      Will be incremented for each raw event written.
 * @max:                Pointer to number of raw events available in buffer.
 *                      Will be decremented for each raw event written.
 * @pulse_width:        Width of pulse in ns.
 * @space_width:        Width of space in ns.
 *
 * Returns:     0 on success.
 *              -ENOBUFS if there isn't enough buffer space to write both raw
 *              events. In this case @max events will have been written.
 */
static inline int ir_raw_gen_pulse_space(struct ir_raw_event **ev,
                                         unsigned int *max,
                                         unsigned int pulse_width,
                                         unsigned int space_width)
{
        if (!*max)
                return -ENOBUFS;
        init_ir_raw_event_duration((*ev)++, 1, pulse_width);
        if (!--*max)
                return -ENOBUFS;
        init_ir_raw_event_duration((*ev)++, 0, space_width);
        --*max;
        return 0;
}

/**
 * struct ir_raw_timings_pd - pulse-distance modulation timings
 * @header_pulse:       duration of header pulse in ns (0 for none)
 * @header_space:       duration of header space in ns
 * @bit_pulse:          duration of bit pulse in ns
 * @bit_space:          duration of bit space (for logic 0 and 1) in ns
 * @trailer_pulse:      duration of trailer pulse in ns
 * @trailer_space:      duration of trailer space in ns
 * @msb_first:          1 if most significant bit is sent first
 */
struct ir_raw_timings_pd {
        unsigned int header_pulse;
        unsigned int header_space;
        unsigned int bit_pulse;
        unsigned int bit_space[2];
        unsigned int trailer_pulse;
        unsigned int trailer_space;
        unsigned int msb_first:1;
};

int ir_raw_gen_pd(struct ir_raw_event **ev, unsigned int max,
                  const struct ir_raw_timings_pd *timings,
                  unsigned int n, u64 data);

/**
 * struct ir_raw_timings_pl - pulse-length modulation timings
 * @header_pulse:       duration of header pulse in ns (0 for none)
 * @bit_space:          duration of bit space in ns
 * @bit_pulse:          duration of bit pulse (for logic 0 and 1) in ns
 * @trailer_space:      duration of trailer space in ns
 * @msb_first:          1 if most significant bit is sent first
 */
struct ir_raw_timings_pl {
        unsigned int header_pulse;
        unsigned int bit_space;
        unsigned int bit_pulse[2];
        unsigned int trailer_space;
        unsigned int msb_first:1;
};

int ir_raw_gen_pl(struct ir_raw_event **ev, unsigned int max,
                  const struct ir_raw_timings_pl *timings,
                  unsigned int n, u64 data);

/*
 * Routines from rc-raw.c to be used internally and by decoders
 */
u64 ir_raw_get_allowed_protocols(void);
int ir_raw_event_prepare(struct rc_dev *dev);
int ir_raw_event_register(struct rc_dev *dev);
void ir_raw_event_free(struct rc_dev *dev);
void ir_raw_event_unregister(struct rc_dev *dev);
int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler);
void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler);
void ir_raw_load_modules(u64 *protocols);
void ir_raw_init(void);

/*
 * lirc interface
 */
#ifdef CONFIG_LIRC
int lirc_dev_init(void);
void lirc_dev_exit(void);
void lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev);
void lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc);
int lirc_register(struct rc_dev *dev);
void lirc_unregister(struct rc_dev *dev);
struct rc_dev *rc_dev_get_from_fd(int fd, bool write);
#else
static inline int lirc_dev_init(void) { return 0; }
static inline void lirc_dev_exit(void) {}
static inline void lirc_raw_event(struct rc_dev *dev,
                                  struct ir_raw_event ev) { }
static inline void lirc_scancode_event(struct rc_dev *dev,
                                       struct lirc_scancode *lsc) { }
static inline int lirc_register(struct rc_dev *dev) { return 0; }
static inline void lirc_unregister(struct rc_dev *dev) { }
#endif

/*
 * bpf interface
 */
#ifdef CONFIG_BPF_LIRC_MODE2
void lirc_bpf_free(struct rc_dev *dev);
void lirc_bpf_run(struct rc_dev *dev, u32 sample);
#else
static inline void lirc_bpf_free(struct rc_dev *dev) { }
static inline void lirc_bpf_run(struct rc_dev *dev, u32 sample) { }
#endif

#endif /* _RC_CORE_PRIV */