CTRL_SH_PCLKDIV
es->ctrl |= DAC2_SRTODIV(val) << CTRL_SH_PCLKDIV;
es->ctrl |= DAC2_SRTODIV(speed) << CTRL_SH_PCLKDIV;
(DAC2_SRTODIV(fixed_rate) << CTRL_SH_PCLKDIV);