Hi Rob, On 3/30/2020 9:31 PM, Rob Herring wrote: > On Fri, Mar 27, 2020 at 04:17:25PM +0530, Kishon Vijay Abraham I wrote: >> Deprecate cdns,max-outbound-regions and cdns,no-bar-match-nbits for >> host mode as both these could be derived from "ranges" and "dma-ranges" >> property. "cdns,max-outbound-regions" property would still be required >> for EP mode. >> >> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> >> --- >> .../bindings/pci/cdns,cdns-pcie-ep.yaml | 2 +- >> .../bindings/pci/cdns,cdns-pcie-host.yaml | 3 +-- >> .../devicetree/bindings/pci/cdns-pcie-ep.yaml | 25 +++++++++++++++++++ >> .../bindings/pci/cdns-pcie-host.yaml | 10 ++++++++ >> .../devicetree/bindings/pci/cdns-pcie.yaml | 8 ------ >> 5 files changed, 37 insertions(+), 11 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >> >> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >> index 2996f8d4777c..50ce5d79d2c7 100644 >> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >> @@ -10,7 +10,7 @@ maintainers: >> - Tom Joseph <tjoseph@xxxxxxxxxxx> >> >> allOf: >> - - $ref: "cdns-pcie.yaml#" >> + - $ref: "cdns-pcie-ep.yaml#" >> - $ref: "pci-ep.yaml#" >> >> properties: >> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >> index cabbe46ff578..84a8f095d031 100644 >> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >> @@ -45,8 +45,6 @@ examples: >> #size-cells = <2>; >> bus-range = <0x0 0xff>; >> linux,pci-domain = <0>; >> - cdns,max-outbound-regions = <16>; >> - cdns,no-bar-match-nbits = <32>; >> vendor-id = <0x17cd>; >> device-id = <0x0200>; >> >> @@ -57,6 +55,7 @@ examples: >> >> ranges = <0x02000000 0x0 0x42000000 0x0 0x42000000 0x0 0x1000000>, >> <0x01000000 0x0 0x43000000 0x0 0x43000000 0x0 0x0010000>; >> + dma-ranges = <0x02000000 0x0 0x0 0x0 0x0 0x1 0x00000000>; >> >> #interrupt-cells = <0x1>; >> >> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >> new file mode 100644 >> index 000000000000..6150a7a7bdbf >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >> @@ -0,0 +1,25 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$id: "http://devicetree.org/schemas/pci/cdns-pcie-ep.yaml#"; >> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"; >> + >> +title: Cadence PCIe Device >> + >> +maintainers: >> + - Tom Joseph <tjoseph@xxxxxxxxxxx> >> + >> +allOf: >> + - $ref: "cdns-pcie.yaml#" >> + >> +properties: >> + cdns,max-outbound-regions: >> + description: maximum number of outbound regions >> + allOf: >> + - $ref: /schemas/types.yaml#/definitions/uint32 >> + minimum: 1 >> + maximum: 32 >> + default: 32 > > I have a feeling that as the PCI endpoint binding evolves this won't be > necessary. I can see a common need to define the number of BARs for an > endpoint and then this will again just be error checking. For every buffer given by the host, we have to create a new outbound translation. If there are no outbound regions, we have to report the error to the endpoint function driver. At-least for reporting the error, we'd need to have this binding no? > > What's the result if you write to a non-existent region in register > CDNS_PCIE_AT_OB_REGION_PCI_ADDR0/1? If the register is non-existent and > doesn't abort, you could detect this instead. I'm not sure if we should ever try to write to a non-existent register though the behavior could be different in different platforms. IMHO maximum number of outbound regions is a HW property and is best described in device tree. Thanks Kishon
