PORT_DSP_DATA
return bus_space_read_2(ess->st, ess->sh, PORT_DSP_DATA);
bus_space_write_2(ess->st, ess->sh, PORT_DSP_DATA, data);
if (bus_space_read_2(ess->st, ess->sh, PORT_DSP_DATA) == reg)
bus_space_write_2(ess->st, ess->sh, PORT_DSP_DATA, reg);
if (bus_space_read_2(ess->st, ess->sh, PORT_DSP_DATA) == data)
bus_space_write_2(ess->st, ess->sh, PORT_DSP_DATA, data);