via_reg_and
#define ADB_SET_STATE_TIP() via_reg_and(VIA1, vBufB, ~vPB5)
#define ADB_SET_SR_INPUT() via_reg_and(VIA1, vACR, ~vSR_OUT)
via_reg_and(VIA1, vDirB, 0xf7); /* register B bit 3: input */
via_reg_and(VIA1, vACR, ~vSR_OUT); /* make sure SR is set
via_reg_and(VIA1, vACR, ~0x10);
#define PM_SET_STATE_ACKOFF() via_reg_and(VIA2, vBufB, ~0x10)
static inline void via_reg_and(int, int, int);