SPI Usage Example

#include "hdf_log.h"
#include "spi_if.h"

void SpiTestSample(void)
{
    int32_t ret;
    struct SpiCfg cfg;                  /* SPI device configuration information */
    struct SpiDevInfo spiDevinfo;       /* SPI device descriptor */
    struct DevHandle *spiHandle = NULL; /* SPI device handle */
    struct SpiMsg msg;                  /* Custom message to be transferred */
    uint8_t rbuff[4] = { 0 };
    uint8_t wbuff[4] = { 0x12, 0x34, 0x56, 0x78 };
    uint8_t wbuff2[4] = { 0xa1, 0xb2, 0xc3, 0xd4 };

    spiDevinfo.busNum = 0;              /* SPI device bus number */
    spiDevinfo.csNum = 0;               /* SPI device CS number */
    spiHandle = SpiOpen(&spiDevinfo);   /* Obtain an SPI device handle based on spiDevinfo. */
    if (spiHandle == NULL) {
        HDF_LOGE("SpiOpen: failed\n");
        return;
    }
    /* Obtain configuration parameters of an SPI device. */
    ret = SpiGetCfg(spiHandle, &cfg);
    if (ret != 0) {
        HDF_LOGE("SpiGetCfg: failed, ret %d\n", ret);
        goto err;
    }
    cfg.maxSpeedHz = 115200;                /* Change the maximum clock frequency to 115200. */
    cfg.bitsPerWord = 8;                    /* Change the word width to 8 bits. */
    /* Set configuration parameters for an SPI device. */
    ret = SpiSetCfg(spiHandle, &cfg);
    if (ret != 0) {
        HDF_LOGE("SpiSetCfg: failed, ret %d\n", ret);
        goto err;
    }
    /* Write specified length of data into an SPI device. */
    ret = SpiWrite(spiHandle, wbuff, 4);
    if (ret != 0) {
        HDF_LOGE("SpiWrite: failed, ret %d\n", ret);
        goto err;
    }
    /* Read data of a specified length from an SPI device. */
    ret = SpiRead(spiHandle, rbuff, 4);
    if (ret != 0) {
        HDF_LOGE("SpiRead: failed, ret %d\n", ret);
        goto err;
    }
    msg.wbuf = wbuff2;  /* Pointer to the data to write */
    msg.rbuf = rbuff;   /* Pointer to the data to read */
    msg.len = 4;        /* The length of the data to be read or written is 4 bits. */
    msg.csChange = 1;   /* Disable the CS before the next transfer. */
    msg.delayUs = 0;    /* No delay before the next transfer */
    msg.speed = 115200; /* Speed of this transfer */
    /* Launch a custom transfer. The number of messages to be transferred is 1. */
    ret = SpiTransfer(spiHandle, &msg, 1);
    if (ret != 0) {
        HDF_LOGE("SpiTransfer: failed, ret %d\n", ret);
        goto err;
    }
err:
    /* Destroy the SPI device handle. */
    SpiClose(spiHandle);
}