BIOS_CNTL
pci_read_config_byte(window->pdev, BIOS_CNTL, &byte);
pci_write_config_byte(window->pdev, BIOS_CNTL,
pci_read_config_byte(pdev, BIOS_CNTL, &byte);
pci_write_config_byte(pdev, BIOS_CNTL, byte | BIOS_WRITE_ENABLE);
pci_read_config_word(pdev, BIOS_CNTL, &word);
pci_write_config_word(pdev, BIOS_CNTL, word | 1);
ret = pci_read_config_word(window->pdev, BIOS_CNTL, &word);
pci_write_config_word(window->pdev, BIOS_CNTL, word & ~1);