On 10/18/2017 10:46 AM, Kishon Vijay Abraham I wrote: > Hi Niklas, > > On Friday 13 October 2017 09:39 PM, Niklas Cassel wrote: >> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx> >> --- >> .../devicetree/bindings/pci/axis,artpec6-pcie.txt | 3 +- >> drivers/pci/dwc/Kconfig | 41 +++-- >> drivers/pci/dwc/Makefile | 4 +- >> drivers/pci/dwc/pcie-artpec6.c | 202 ++++++++++++++++++++- >> 4 files changed, 233 insertions(+), 17 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt >> index 4e4aee4439ea..33eef7ae5a23 100644 >> --- a/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt >> +++ b/Documentation/devicetree/bindings/pci/axis,artpec6-pcie.txt >> @@ -4,7 +4,8 @@ This PCIe host controller is based on the Synopsys DesignWare PCIe IP >> and thus inherits all the common properties defined in designware-pcie.txt. >> >> Required properties: >> -- compatible: "axis,artpec6-pcie", "snps,dw-pcie" >> +- compatible: "axis,artpec6-pcie", "snps,dw-pcie" for ARTPEC-6 in RC mode; >> + "axis,artpec6-pcie-ep", "snps,dw-pcie" for ARTPEC-6 in EP mode; > > If "snps,dw-pcie" is used for both RC and EP mode, how do we differentiate > between the modes? Hello Kishon, Most DWC core based PCIe controllers have the following text in their DT binding: "This PCIe host controller is based on the Synopsys DesignWare PCIe IP and thus inherits all the common properties defined in designware-pcie.txt." It seems like DRA7xx is one of few DWC core based bindings that does not include this text. However, I can see that you've added "EP mode:" and "RC mode:" headings to designware-pcie.txt. But still the top of the file says: Required properties: - compatible: should contain "snps,dw-pcie" to identify the core. However, I don't think there's necessarily any contradiction here, since axis,artpec6-pcie.txt says: compatible: "axis,artpec6-pcie", "snps,dw-pcie" for ARTPEC-6 in RC mode; compatible: "axis,artpec6-pcie-ep", "snps,dw-pcie" for ARTPEC-6 in EP mode; And according to: https://elinux.org/Device_Tree_Usage#Understanding_the_compatible_Property The first string in the list specifies the exact device. The following strings represent other devices that the device is compatible with. Their example is: The compatible property for the MPC8349 serial device should therefore be: compatible = "fsl,mpc8349-uart", "ns16550". In this case, fsl,mpc8349-uart specifies the exact device, and ns16550 states that it is register-level compatible with a National Semiconductor 16550 UART. The exact device is "axis,artpec6-pcie-ep", but it is register compatible with "snps,dw-pcie". But perhaps Rob Herring could correct me if I'm wrong. Regards, Niklas
