#ifndef __AP_HAL_LINUX_RCINPUT_H__
#define __AP_HAL_LINUX_RCINPUT_H__

#include <AP_HAL_Linux.h>

#define LINUX_RC_INPUT_NUM_CHANNELS 16

#define RCIN_PRUSS_SHAREDRAM_BASE   0x4a312000
#define NUM_RING_ENTRIES            200

class Linux::LinuxRCInput : public AP_HAL::RCInput {
public:
    LinuxRCInput();
    void init(void* machtnichts);
    bool new_input();
    uint8_t num_channels();
    uint16_t read(uint8_t ch);
    uint8_t read(uint16_t* periods, uint8_t len);

    bool set_overrides(int16_t *overrides, uint8_t len);
    bool set_override(uint8_t channel, int16_t override);
    void clear_overrides();

    void _timer_tick(void);

 private:
    volatile bool new_rc_input;
    
    uint16_t _pulse_capt[LINUX_RC_INPUT_NUM_CHANNELS];
    uint8_t  _num_channels;
    /* override state */
    uint16_t _override[LINUX_RC_INPUT_NUM_CHANNELS];

    // shared ring buffer with the PRU which records pin transitions
    struct ring_buffer {
        volatile uint16_t ring_head; // owned by ARM CPU
        volatile uint16_t ring_tail; // owned by the PRU
        struct {
               uint16_t pin_value;
               uint16_t delta_t;
        } buffer[NUM_RING_ENTRIES];
    };
    volatile struct ring_buffer *ring_buffer;

    // the channel we will receive input from next, or -1 when not synchronised
    int8_t _channel_counter;

    // time spent in the low state
    uint16_t _s0_time;
    void _process_pulse(uint16_t width_usec);
};

#endif // __AP_HAL_LINUX_RCINPUT_H__