2、AD5300，spi
int spi_send(struct st_spi_device *spi_bus,const void *send_buff,unsigned short send_size); //只发送
/*
mode范围0—3
*/
void ad5300_set(u8 mode,u8 out)
{
        u16 send_data;
        u8 send_buff[2];

        send_data = ((mode << 8) | out)<<4;   //这个逻辑手册，如下图
        send_buff[0] = (send_data >> 8)&0xff; //高位在前
        send_buff[1] = send_data & 0xff;
        spi_send(spi1,send_buff,2);
}