spi.h

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/***************************************************************************/
#ifndef SPI_H_
#define SPI_H_
 
/******************************************************************************/
/***************************** Include Files **********************************/
/******************************************************************************/
 
#include <stdint.h>
 
/******************************************************************************/
/********************** Macros and Constants Definitions **********************/
/******************************************************************************/
 
#define SPI_CPHA    0x01
#define SPI_CPOL    0x02
 
/******************************************************************************/
/*************************** Types Declarations *******************************/
/******************************************************************************/
 
typedef enum spi_mode {
    SPI_MODE_0 = (0 | 0),
    SPI_MODE_1 = (0 | SPI_CPHA),
    SPI_MODE_2 = (SPI_CPOL | 0),
    SPI_MODE_3 = (SPI_CPOL | SPI_CPHA)
} spi_mode;
 
typedef enum spi_bit_order {
    SPI_BIT_ORDER_MSB_FIRST = 0,
    SPI_BIT_ORDER_LSB_FIRST = 1,
} spi_bit_order;
 
struct spi_msg {
    uint8_t         *tx_buff;
    uint8_t         *rx_buff;
    uint32_t        bytes_number;
    uint8_t         cs_change;
};
 
struct spi_platform_ops ;
 
typedef struct spi_init_param {
    uint32_t    device_id;
    uint32_t    max_speed_hz;
    uint8_t     chip_select;
    enum spi_mode   mode;
    enum spi_bit_order  bit_order;
    const struct spi_platform_ops *platform_ops;
    void        *extra;
} spi_init_param;
 
typedef struct spi_desc {
    uint32_t    device_id;
    uint32_t    max_speed_hz;
    uint8_t     chip_select;
    enum spi_mode   mode;
    enum spi_bit_order  bit_order;
    const struct spi_platform_ops *platform_ops;
    void        *extra;
} spi_desc;
 
struct spi_platform_ops {
    int32_t (*init)(struct spi_desc **, const struct spi_init_param *);
    int32_t (*write_and_read)(struct spi_desc *, uint8_t *, uint16_t);
    int32_t (*transfer)(struct spi_desc *, struct spi_msg *, uint32_t);
    int32_t (*remove)(struct spi_desc *);
};
 
/******************************************************************************/
/************************ Functions Declarations ******************************/
/******************************************************************************/
 
/* Initialize the SPI communication peripheral. */
int32_t spi_init(struct spi_desc **desc,
         const struct spi_init_param *param);
 
/* Free the resources allocated by spi_init(). */
int32_t spi_remove(struct spi_desc *desc);
 
/* Write and read data to/from SPI. */
int32_t spi_write_and_read(struct spi_desc *desc,
               uint8_t *data,
               uint16_t bytes_number);
 
/* Iterate over the spi_msg array and send all messages at once */
int32_t spi_transfer(struct spi_desc *desc, struct spi_msg *msgs, uint32_t len);
 
 
#endif // SPI_H_