dmac_reg_read
dalgn = dmac_reg_read(sc, DMAC_DALGN);
dcsr = dmac_reg_read(sc, DMAC_DCSR(channel));
if (dmac_reg_read(sc, DMAC_DCSR(channel)) & DCSR_STOPSTATE)
rv = dmac_reg_read(sc, DMAC_DINT);
dmac_reg_read(sc, DMAC_DINT) & DMAC_DINT_MASK);
rv = dmac_reg_read(sc, DMAC_DCSR(dxs->dxs_channel));