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. Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx> --- Hi, I have verified this lightly by booting a kernel with PARPORT_PC and PARPORT_SERIAL enabled on a RISC-V HiFive Unmatched system. While I do have a PCIe parallel port option available that I could use with my RISC-V machine (based on the OxSemi OXPCIe952 chip) it is currently plugged in the wrong system, and both machines are in my remote lab I have currently no visit scheduled to in the near future. For the record the device reports as: PCI parallel port detected: 1415:c118, I/O at 0x1000(0x1008), IRQ 18 parport1: PC-style at 0x1000 (0x1008), irq 18, using FIFO [PCSPP,TRISTATE,COMPAT,EPP,ECP] in the other system. I'll see if I can verify it with the Unmatched at the next opportunity, though it seems like an overkill to me given that a PC-style parallel port is a generic PCIe device. The OXPCIe952 implements a multifunction device, so it doesn't rely on PARPORT_SERIAL. NB platforms to be updated for <asm/parport.h> generation were chosen by the presence of the HAVE_PCI or FORCE_PCI option from ones that do not already have or generate that header, except for s390, now excluded. Let me know if I got anything wrong here. Maciej Changes from v1: - Exclude s390 systems, update the change description accordingly. --- arch/arm64/include/asm/Kbuild | 1 + arch/csky/include/asm/Kbuild | 1 + arch/riscv/include/asm/Kbuild | 1 + arch/um/include/asm/Kbuild | 1 + arch/xtensa/include/asm/Kbuild | 1 + drivers/parport/Kconfig | 4 ++-- 6 files changed, 7 insertions(+), 2 deletions(-) linux-parport-pc-pci.diff Index: linux-macro/arch/arm64/include/asm/Kbuild =================================================================== --- linux-macro.orig/arch/arm64/include/asm/Kbuild +++ linux-macro/arch/arm64/include/asm/Kbuild @@ -3,6 +3,7 @@ generic-y += early_ioremap.h generic-y += mcs_spinlock.h generic-y += qrwlock.h generic-y += qspinlock.h +generic-y += parport.h generic-y += user.h generated-y += cpucaps.h Index: linux-macro/arch/csky/include/asm/Kbuild =================================================================== --- linux-macro.orig/arch/csky/include/asm/Kbuild +++ linux-macro/arch/csky/include/asm/Kbuild @@ -4,5 +4,6 @@ generic-y += extable.h generic-y += gpio.h generic-y += kvm_para.h generic-y += qrwlock.h +generic-y += parport.h generic-y += user.h generic-y += vmlinux.lds.h Index: linux-macro/arch/riscv/include/asm/Kbuild =================================================================== --- linux-macro.orig/arch/riscv/include/asm/Kbuild +++ linux-macro/arch/riscv/include/asm/Kbuild @@ -2,5 +2,6 @@ generic-y += early_ioremap.h generic-y += flat.h generic-y += kvm_para.h +generic-y += parport.h generic-y += user.h generic-y += vmlinux.lds.h Index: linux-macro/arch/um/include/asm/Kbuild =================================================================== --- linux-macro.orig/arch/um/include/asm/Kbuild +++ linux-macro/arch/um/include/asm/Kbuild @@ -17,6 +17,7 @@ generic-y += mcs_spinlock.h generic-y += mmiowb.h generic-y += module.lds.h generic-y += param.h +generic-y += parport.h generic-y += percpu.h generic-y += preempt.h generic-y += softirq_stack.h Index: linux-macro/arch/xtensa/include/asm/Kbuild =================================================================== --- linux-macro.orig/arch/xtensa/include/asm/Kbuild +++ linux-macro/arch/xtensa/include/asm/Kbuild @@ -4,6 +4,7 @@ generic-y += extable.h generic-y += kvm_para.h generic-y += mcs_spinlock.h generic-y += param.h +generic-y += parport.h generic-y += qrwlock.h generic-y += qspinlock.h generic-y += user.h Index: linux-macro/drivers/parport/Kconfig =================================================================== --- linux-macro.orig/drivers/parport/Kconfig +++ linux-macro/drivers/parport/Kconfig @@ -42,7 +42,7 @@ if PARPORT config PARPORT_PC tristate "PC-style hardware" - depends on ARCH_MIGHT_HAVE_PC_PARPORT + depends on ARCH_MIGHT_HAVE_PC_PARPORT || (PCI && !S390) help You should say Y here if you have a PC-style parallel port. All IBM PC compatible computers and some Alphas have PC-style @@ -77,7 +77,7 @@ config PARPORT_PC_FIFO config PARPORT_PC_SUPERIO bool "SuperIO chipset support" - depends on PARPORT_PC && !PARISC + depends on ARCH_MIGHT_HAVE_PC_PARPORT && PARPORT_PC && !PARISC help Saying Y here enables some probes for Super-IO chipsets in order to find out things like base addresses, IRQ lines and DMA channels. It
