ULPI_SCRATCH
ret = isp1704_write(isp, ULPI_SCRATCH, 0xaa);
ret = isp1704_read(isp, ULPI_SCRATCH);
ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
ret = ulpi_read(ulpi, ULPI_SCRATCH);
ulpi_print("Scratch Register ", ULPI_SCRATCH);
ret = usb_phy_io_write(phy, val, ULPI_SCRATCH);
ret = usb_phy_io_read(phy, ULPI_SCRATCH);