Function rt_msd_init

components/drivers/spi/dev_spi_msd.c:460–1198

RT-Thread Device Driver Interface */

/* RT-Thread Device Driver Interface */
static rt_err_t rt_msd_init(rt_device_t dev)
{
    struct msd_device *msd = (struct msd_device *)dev;
    uint8_t response[MSD_RESPONSE_MAX_LEN];
    rt_err_t result = RT_EOK;
    rt_tick_t tick_start;
    uint32_t OCR;

    if (msd->spi_device == RT_NULL)
    {
        MSD_DEBUG("[err] the SPI SD device has no SPI!\r\n");
        return -RT_EIO;
    }

    /* config spi */
    {
        struct rt_spi_configuration cfg;
        cfg.data_width = 8;
        cfg.mode = RT_SPI_MODE_0 | RT_SPI_MSB; /* SPI Compatible Modes 0 */
        cfg.max_hz = 1000 * 400; /* 400kbit/s */
        rt_spi_configure(msd->spi_device, &cfg);
    } /* config spi */

    /* init SD card */
    {
        struct rt_spi_message message;

        result = MSD_take_owner(msd->spi_device);

        if (result != RT_EOK)
        {
            goto _exit;
        }

        rt_spi_release(msd->spi_device);

        /* The host shall supply power to the card so that the voltage is reached to Vdd_min within 250ms and
           start to supply at least 74 SD clocks to the SD card with keeping CMD line to high.
           In case of SPI mode, CS shall be held to high during 74 clock cycles. */
        {
            uint8_t send_buffer[100]; /* 100byte > 74 clock */

            /* initial message */
            rt_memset(send_buffer, DUMMY, sizeof(send_buffer));
            message.send_buf = send_buffer;
            message.recv_buf = RT_NULL;
            message.length = sizeof(send_buffer);
            message.cs_take = message.cs_release = 0;

            /* transfer message */
            msd->spi_device->bus->ops->xfer(msd->spi_device, &message);
        } /* send 74 clock */

        /* Send CMD0 (GO_IDLE_STATE) to put MSD in SPI mode */
        {
            tick_start = rt_tick_get();

            while (1)