pmu_write_reg
static inline void pmu_write_reg(struct pmu_softc *, int, uint8_t);
pmu_write_reg(sc, vIER, 0x90); /* enable VIA interrupts */
pmu_write_reg(sc, vSR, data);
pmu_write_reg(sc, vIER, intreg);
pmu_write_reg(sc, vIER, (intreg == 0) ? 0 : 0x90);
pmu_write_reg(sc, vACR, reg);
pmu_write_reg(sc, vACR, reg);
pmu_write_reg(sc, vBufB, reg);
pmu_write_reg(sc, vBufB, reg);
pmu_write_reg(sc, vIFR, 0x90); /* Clear 'em */