IGS_REG_BASE
dc->dc_iobase + IGS_REG_BASE, IGS_REG_SIZE,
ret = bus_space_map(iot, iobase + IGS_REG_BASE, IGS_REG_SIZE, ioflags,
#define IGS_REG_(x) ((x) - IGS_REG_BASE)
dc->dc_iobase + IGS_REG_BASE, IGS_REG_SIZE,