File content as of revision 0:3afcd581558d:

/***************************************************************************//**
 *   @file   spi.h
 *   @brief  Header file of SPI Interface
 *   @author DBogdan (dragos.bogdan@analog.com)
********************************************************************************
 * Copyright 2019(c) Analog Devices, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Analog Devices, Inc. nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *  - The use of this software may or may not infringe the patent rights
 *    of one or more patent holders.  This license does not release you
 *    from the requirement that you obtain separate licenses from these
 *    patent holders to use this software.
 *  - Use of the software either in source or binary form, must be run
 *    on or directly connected to an Analog Devices Inc. component.
 *
 * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************/

#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 *******************************/
/******************************************************************************/

/**
 * @enum spi_mode
 * @brief SPI configuration for clock phase and polarity.
 */
typedef enum spi_mode {
	/** Data on rising, shift out on falling */
	SPI_MODE_0 = (0 | 0),
	/** Data on falling, shift out on rising */
	SPI_MODE_1 = (0 | SPI_CPHA),
	/** Data on falling, shift out on rising */
	SPI_MODE_2 = (SPI_CPOL | 0),
	/** Data on rising, shift out on falling */
	SPI_MODE_3 = (SPI_CPOL | SPI_CPHA)
} spi_mode;

/**
 * @struct spi_platform_ops
 * @brief Structure holding SPI function pointers that point to the platform
 * specific function
 */
struct spi_platform_ops ;

/**
 * @struct spi_init_param
 * @brief Structure holding the parameters for SPI initialization
 */
typedef struct spi_init_param {
	/** maximum transfer speed */
	uint32_t	max_speed_hz;
	/** SPI chip select */
	uint8_t		chip_select;
	/** SPI mode */
	enum spi_mode	mode;
	const struct spi_platform_ops *platform_ops;
	/**  SPI extra parameters (device specific) */
	void		*extra;
} spi_init_param;

/**
 * @struct spi_desc
 * @brief Structure holding SPI descriptor.
 */
typedef struct spi_desc {
	/** maximum transfer speed */
	uint32_t	max_speed_hz;
	/** SPI chip select */
	uint8_t		chip_select;
	/** SPI mode */
	enum spi_mode	mode;
	const struct spi_platform_ops *platform_ops;
	/**  SPI extra parameters (device specific) */
	void		*extra;
} spi_desc;

/**
 * @struct spi_platform_ops
 * @brief Structure holding SPI function pointers that point to the platform
 * specific function
 */
struct spi_platform_ops {
	/** SPI initialization function pointer */
	int32_t (*spi_ops_init)(struct spi_desc **, const struct spi_init_param *);
	/** SPI write/read function pointer */
	int32_t (*spi_ops_write_and_read)(struct spi_desc *, uint8_t *, uint16_t);
	/** SPI remove function pointer */
	int32_t (*spi_ops_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);

#endif // SPI_H_