MCP4728_PDMODE_MASK
outbuf[offset] |= FIELD_PREP(MCP4728_PDMODE_MASK,
outbuf[1] |= FIELD_PREP(MCP4728_PDMODE_MASK, ch->pd_mode + 1);
ch->pd_mode = FIELD_GET(MCP4728_PDMODE_MASK, r2);