spi.h

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/*
 * SPDX-FileCopyrightText: 2014-2016 Freie Universität Berlin
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once

 
#include <endian.h>
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
 
#include "periph_cpu.h"
#include "periph_conf.h"
#include "periph/gpio.h"
 
#ifdef __cplusplus
extern "C" {
#endif

#ifndef CONFIG_SPI_DMA_THRESHOLD_BYTES
#define CONFIG_SPI_DMA_THRESHOLD_BYTES  16
#endif

#ifndef SPI_DEV
#define SPI_DEV(x)      (x)
#endif

#ifndef SPI_UNDEF
#define SPI_UNDEF       (UINT_FAST8_MAX)
#endif

#ifndef SPI_CS_UNDEF
#define SPI_CS_UNDEF    (GPIO_UNDEF)
#endif

#ifndef SPI_HWCS
#define SPI_HWCS(x)     (SPI_CS_UNDEF)
#endif

#ifndef HAVE_SPI_T
typedef uint_fast8_t spi_t;
#endif

#ifndef HAVE_SPI_CS_T
typedef gpio_t spi_cs_t;
#endif

enum {
    SPI_OK          =  0,       
    SPI_NODEV       = -ENXIO,   
    SPI_NOCS        = -EINVAL,  
    SPI_NOMODE      = -EINVAL,  
    SPI_NOCLK       = -EINVAL   
};

#ifndef HAVE_SPI_MODE_T
typedef enum {
    SPI_MODE_0 = 0,         
    SPI_MODE_1,             
    SPI_MODE_2,             
    SPI_MODE_3              
} spi_mode_t;
#endif

#ifndef HAVE_SPI_CLK_T
typedef enum {
    SPI_CLK_100KHZ = 0,     
    SPI_CLK_400KHZ,         
    SPI_CLK_1MHZ,           
    SPI_CLK_5MHZ,           
    SPI_CLK_10MHZ           
} spi_clk_t;
#endif

void spi_init(spi_t bus);

void spi_init_pins(spi_t bus);

int spi_init_cs(spi_t bus, spi_cs_t cs);
 
#if defined(MODULE_PERIPH_SPI_RECONFIGURE) || DOXYGEN

void spi_deinit_pins(spi_t dev);
 
#if DOXYGEN

gpio_t spi_pin_miso(spi_t dev);

gpio_t spi_pin_mosi(spi_t dev);

gpio_t spi_pin_clk(spi_t dev);
 
#endif /* DOXYGEN */
#endif /* MODULE_PERIPH_SPI_RECONFIGURE */
 
#if defined(MODULE_PERIPH_SPI_GPIO_MODE) || DOXYGEN

typedef struct {
    gpio_mode_t mosi;       
    gpio_mode_t miso;       
    gpio_mode_t sclk;       
} spi_gpio_mode_t;

int spi_init_with_gpio_mode(spi_t bus, const spi_gpio_mode_t* mode);
#endif

void spi_acquire(spi_t bus, spi_cs_t cs, spi_mode_t mode, spi_clk_t clk);

void spi_release(spi_t bus);

uint8_t spi_transfer_byte(spi_t bus, spi_cs_t cs, bool cont, uint8_t out);

void spi_transfer_bytes(spi_t bus, spi_cs_t cs, bool cont,
                        const void *out, void *in, size_t len);

uint8_t spi_transfer_reg(spi_t bus, spi_cs_t cs, uint8_t reg, uint8_t out);

void spi_transfer_regs(spi_t bus, spi_cs_t cs, uint8_t reg,
                       const void *out, void *in, size_t len);

static inline uint16_t spi_transfer_u16_be(spi_t bus, spi_cs_t cs, bool cont, uint16_t host_number)
{
    const uint16_t send = htobe16(host_number);
    uint16_t receive;
    spi_transfer_bytes(bus, cs, cont, &send, &receive, sizeof(receive));
    return be16toh(receive);
}
 
#ifdef __cplusplus
}
#endif