TCTL_EN
l->tctl = TCTL_EN | TCTL_PSP | TCTL_CT(15);
CSR_WRITE(sc, WMREG_TCTL, reg | TCTL_EN);
sc->sc_tctl = TCTL_EN | TCTL_PSP | TCTL_RTLC
CSR_WRITE(sc, WMREG_TCTL, tctl & ~TCTL_EN);