Dave Jones wrote:

Make PIO/MMIO a runtime thing via a module parameter.
This is needed to support devices that only work with PIO
without penalising devices that work fine with MMIO in
distro kernels.

Signed-off-by: Dave Jones <redacted>

two comments:

1) should use pci_iomap() for both PIO and MMIO

2) modparam should be "use_io" mirroring existing drivers