In a future patch, the port I/O functions (`inb()`, `outb()`, and friends will only be declared in the `HAS_IOPORT` configuration option is enabled. The amplc_dio200_pci module supports various Amplicon PCI and PCI Express devices. Some of the supported devices (the PCI ones) use port I/O, and some of them (the PCIe ones) only use memory-mapped I/O. Conditionally compile in support for the devices that need port I/O if and only if the `CONFIG_HAS_IOPORT` macro is defined. Add a run-time check in `dio200_pci_auto_attach()` to return an error if the device actually requires port I/O (based on the PCI BAR resource flags) but the `HAS_IOPORT` configuration option is not enabled. Cc: Arnd Bergmann <arnd@kernel.org> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20230913170712.111719-11-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>