• Maciej W. Rozycki's avatar
    parport_pc: Also enable driver for PCI systems · 66bcd060
    Maciej W. Rozycki authored
    Nowadays PC-style parallel ports come in the form of PCI and PCIe option
    cards and there are some combined parallel/serial option cards as well
    that we handle in the parport subsystem.  There is nothing in particular
    that would prevent them from being used in any system equipped with PCI
    or PCIe connectivity, except that we do not permit the PARPORT_PC config
    option to be selected for platforms for which ARCH_MIGHT_HAVE_PC_PARPORT
    has not been set for.
    
    The only PCI platforms that actually can't make use of PC-style parallel
    port hardware are those newer PCIe systems that have no support for I/O
    cycles in the host bridge, required by such parallel ports.  Notably,
    this includes the s390 arch, which has port I/O accessors that cause
    compilation warnings (promoted to errors with `-Werror'), and there are
    other cases such as the POWER9 PHB4 device, though this one has variable
    port I/O accessors that depend on the particular system.  Also it is not
    clear whether the serial port side of devices enabled by PARPORT_SERIAL
    uses port I/O or MMIO.  Finally Super I/O solutions are always either
    ISA or platform devices.
    
    Make the PARPORT_PC option selectable also for PCI systems then, except
    for the s390 arch, however limit the availability of PARPORT_PC_SUPERIO
    to platforms that enable ARCH_MIGHT_HAVE_PC_PARPORT.  Update platforms
    accordingly for the required <asm/parport.h> header.
    Acked-by: default avatarSudip Mukherjee <sudipm.mukherjee@gmail.com>
    Signed-off-by: default avatarMaciej W. Rozycki <macro@orcam.me.uk>
    Link: https://lore.kernel.org/r/alpine.DEB.2.21.2202141955550.34636@angie.orcam.me.ukSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    66bcd060
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