spi.h

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/* Copyright 2018 Wirepas Ltd. All Rights Reserved.
 *
 * See file LICENSE.txt for full license details.
 *
 */
 
#ifndef SPI_H_
#define SPI_H_
 
#include <stdbool.h>
#include <stdint.h>
 
typedef enum
{
    SPI_MODE_LOW_FIRST,     //< Low Polarity, First Clock edge
    SPI_MODE_LOW_SECOND,    //< Low Polarity, Second Clock edge
    SPI_MODE_HIGH_FIRST,    //< High Polarity, First Clock edge
    SPI_MODE_HIGH_SECOND    //< High Polarity, Second Clock edge
} spi_mode_e;
 
typedef enum
{
    SPI_ORDER_MSB,  //< Most Significant Bit first
    SPI_ORDER_LSB   //< Less Significant Bit first
} spi_bit_order_e;
 
typedef struct
{
    uint32_t        clock;      //< SPI speed in Hz
    spi_mode_e      mode;       //< SPI mode of operation
    spi_bit_order_e bit_order;  //< SPI bit order
} spi_conf_t;
 
typedef struct
{
    uint8_t *   write_ptr;  //< Pointer to bytes to write (Must be NULL for pure read)
    size_t      write_size; //< Number of bytes to write (Must be 0 for pure read)
    uint8_t *   read_ptr;   //< Pointer to store bytes to read (Must be NULL for pure write)
    size_t      read_size;  //< Number of bytes to read (Must be 0 for pure write)
    uint32_t    custom;     //< Custom param (can be used to implement state machine)
} spi_xfer_t;
 
typedef enum
{
    SPI_RES_OK,
    SPI_RES_INVALID_CONFIG,
    SPI_RES_INVALID_XFER,
    SPI_RES_NOT_INITIALIZED,
    SPI_RES_ALREADY_INITIALIZED,
    SPI_RES_BUSY,
    SPI_RES_BLOCKING_NOT_AVAILABLE,
    SPI_RES_ONLY_BLOCKING_AVAILABLE
} spi_res_e;
 
typedef void (*spi_on_transfer_done_cb_f)(spi_res_e res,
                                      spi_xfer_t * xfer_p);
 
spi_res_e SPI_init(spi_conf_t * conf_p);
 
spi_res_e SPI_close();
 
spi_res_e SPI_transfer(spi_xfer_t * xfer_p,
                       spi_on_transfer_done_cb_f cb);
 
 
#endif /* SPI_H_ */