CRD3
viafb_write_reg_mask(CRD3, VIACR, 0xC0, BIT6 + BIT7);
viafb_write_reg_mask(CRD3, VIACR, 0, BIT0);
viafb_write_reg_mask(CRD3, VIACR, 0, BIT6 + BIT7);