THINKPAD_EC_MASK_VOL
val = val_ec & THINKPAD_EC_MASK_VOL;
(val_ec & (~THINKPAD_EC_MASK_VOL));
val_ec = arg + (val_ec & (~THINKPAD_EC_MASK_VOL));
val = val_ec & THINKPAD_EC_MASK_VOL;
val = val_ec & THINKPAD_EC_MASK_VOL;