Re: [PATCH v2 6/9] PCI: cadence: Add host driver for Cadence PCIe controller
From: Bjorn Helgaas
Date: Thu Dec 28 2017 - 18:01:21 EST
On Mon, Dec 18, 2017 at 07:16:06PM +0100, Cyrille Pitchen wrote:
> This patch adds support to the Cadence PCIe controller in host mode.
> The "cadence/" entry in drivers/pci/Makefile is placed after the
> "endpoint/" entry so when the next patch introduces a EPC driver for the
> Cadence PCIe controller, drivers/pci/cadence/pcie-cadence-ep.o will be
> linked after drivers/pci/endpoint/*.o objects, otherwise the built-in
> pci-cadence-ep driver would be probed before the PCI endpoint libraries
> would have been initialized, which would result in a kernel crash.
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxxxxxxxxxx>
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index 7284a7f6ad1e..a66ddb347798 100644
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -54,5 +54,6 @@ obj-y += host/
> obj-y += switch/
> obj-$(CONFIG_PCI_ENDPOINT) += endpoint/
> +obj-$(CONFIG_PCI_CADENCE) += cadence/
> # PCI dwc controller drivers
> obj-y += dwc/
I don't like the fact that the cadence/ rule looks different than the
dwc/ rule for no obvious reason. With some work, the dwc/ rule could
maybe be made to look like:
obj-$(CONFIG_PCIE_DW) += dwc/
I *think* that should actually be pretty easy. Everything in
drivers/pci/dwc/Kconfig selects PCIE_DW if set, either via
PCIE_DW_HOST or PCIE_DW_EP.
> diff --git a/drivers/pci/cadence/Kconfig b/drivers/pci/cadence/Kconfig
> new file mode 100644
> index 000000000000..0d15b40861e9
> --- /dev/null
> +++ b/drivers/pci/cadence/Kconfig
> @@ -0,0 +1,24 @@
> +menuconfig PCI_CADENCE
> + bool "Cadence PCI controllers support"
> + depends on PCI && HAS_IOMEM
> + help
> + Say Y here if you want to support some Cadence PCI controller.
> + When in doubt, say N.
> +if PCI_CADENCE
> +config PCIE_CADENCE
> + bool
> +config PCIE_CADENCE_HOST
> + bool "Cadence PCIe host controller"
> + depends on OF
> + select IRQ_DOMAIN
> + select PCIE_CADENCE
> + help
> + Say Y here if you want to support the Cadence PCIe controller in host
> + mode. This PCIe controller may be embedded into many different vendors
> + SoCs.
> +endif # PCI_CADENCE
Can you just use the same strategy as pci/dwc/Kconfig does, i.e., omit
the top-level PCI_CADENCE symbol? If we don't need it for dwc, with
its dozen drivers, we probably don't need it for the one or two