#ifndef __AP_HAL_LINUX_STORAGE_FRAM_H__
#define __AP_HAL_LINUX_STORAGE_FRAM_H__

#include <AP_HAL.h>
#include "AP_HAL_Linux_Namespace.h"

#define OPCODE_WREN   0b0110        /* Write Enable Latch */
#define OPCODE_WRDI   0b0100        /* Reset Write Enable Latch */
#define OPCODE_RDSR   0b0101        /* Read Status Register */
#define OPCODE_WRSR   0b0001        /* Write Status Register */
#define OPCODE_READ   0b0011        /* Read Memory */
#define OPCODE_WRITE  0b0010        /* Write Memory */
#define OPCODE_RDID   0b10011111    /* Read Device ID */

#define LINUX_STORAGE_SIZE 4096
#define LINUX_STORAGE_MAX_WRITE 512
#define LINUX_STORAGE_LINE_SHIFT 9
#define LINUX_STORAGE_LINE_SIZE (1<<LINUX_STORAGE_LINE_SHIFT)
#define LINUX_STORAGE_NUM_LINES (LINUX_STORAGE_SIZE/LINUX_STORAGE_LINE_SIZE)

class Linux::LinuxStorage : public AP_HAL::Storage 
{
public:
    LinuxStorage();
    void init(void* machtnichts) {}
    uint8_t  read_byte(uint16_t loc);
    uint16_t read_word(uint16_t loc);
    uint32_t read_dword(uint16_t loc);
    void     read_block(void *dst, uint16_t src, size_t n);

    void write_byte(uint16_t loc, uint8_t value);
    void write_word(uint16_t loc, uint16_t value);
    void write_dword(uint16_t loc, uint32_t value);
    void write_block(uint16_t dst, const void* src, size_t n);

    void _timer_tick(void);

private:
    uint32_t fptr;
    int _fd;
    volatile bool _initialised;

    int32_t write(uint16_t fd, uint8_t *Buff, uint16_t NumBytes);
    int32_t read(uint16_t fd, uint8_t *Buff, uint16_t NumBytes);
    uint32_t lseek(uint16_t fd,uint32_t offset,uint16_t whence);
    int8_t open();

    int8_t _register_write( uint8_t* src, uint16_t addr, uint16_t len );
    int8_t _register_read( uint16_t addr, uint8_t opcode );
    int8_t _write_enable(bool enable);
    int8_t transaction(uint8_t* tx, uint8_t* rx, uint16_t len);

    void _storage_create(void);
    void _storage_open(void);
    void _mark_dirty(uint16_t loc, uint16_t length);
    

    AP_HAL::SPIDeviceDriver *_spi;
    AP_HAL::Semaphore *_spi_sem;

    uint8_t _buffer[LINUX_STORAGE_SIZE];
    volatile uint32_t _dirty_mask;
};
#endif // __AP_HAL_LINUX_STORAGE_H__