static int w25_write_read(int fd , const char* wbuf,unsigned int wlen,

    const char* rbuf , unsigned int rlen){



    int ret = 0;

    struct spi_ioc_transfer tr[2] = {

        {

            .tx_buf = (unsigned long)wbuf,

            .rx_buf = 0,

            .len = wlen,

            .speed_hz = speed,

        },

        {

            .tx_buf = 0,

            .rx_buf = (unsigned long)rbuf,

            .len = rlen,

            .speed_hz = speed,

        },

    };



    ret = ioctl(fd , SPI_IOC_MESSAGE(2) , tr);



    return ret;

}