[v3,2/2] dt-bindings: designware: add binding for Designware PCIe in ECAM mode

Message ID 20170828180437.2646-3-ard.biesheuvel@linaro.org
State Changes Requested
Headers show
Series
  • pci: add support for firmware initialized designware RCs
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Commit Message

Ard Biesheuvel Aug. 28, 2017, 6:04 p.m.
Describe the binding for firmware-configured instances of the Synopsys
Designware PCIe controller in RC mode, that are almost but not quite
ECAM compliant.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt | 42 ++++++++++++++++++++
 1 file changed, 42 insertions(+)

Comments

Rob Herring Aug. 31, 2017, 2:23 p.m. | #1
On Mon, Aug 28, 2017 at 1:04 PM, Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> Describe the binding for firmware-configured instances of the Synopsys
> Designware PCIe controller in RC mode, that are almost but not quite
> ECAM compliant.
>
> Cc: Rob Herring <robh@kernel.org>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt | 42 ++++++++++++++++++++
>  1 file changed, 42 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>

Patch

diff --git a/Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt b/Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt
new file mode 100644
index 000000000000..29bad1337c87
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt
@@ -0,0 +1,42 @@ 
+* Synopsys Designware PCIe root complex in ECAM mode
+
+In some cases, firmware may already have configured the Synopsys Designware
+PCIe controller in RC mode with static ATU window mappings that cover all
+config, MMIO and I/O spaces in a [mostly] ECAM compatible fashion.
+In this case, there is no need for the OS to perform any low level setup
+of clocks, PHYs or device registers, nor is there any reason for the driver
+to reconfigure ATU windows for config and/or IO space accesses at runtime.
+
+In cases where the IP was synthesized with a minimum ATU window size of
+64 KB, it cannot be supported by the generic ECAM driver, because it
+requires special config space accessors that filter accesses to device #1
+and beyond on the first bus.
+
+Required properties:
+- compatible: "marvell,armada8k-pcie-ecam" or
+              "socionext,synquacer-pcie-ecam" or
+              "snps,dw-pcie-ecam" (must be preceded by a more specific match)
+
+Please refer to the binding document of "pci-host-ecam-generic" in the
+file host-generic-pci.txt for a description of the remaining required
+and optional properties.
+
+Example:
+
+    pcie1: pcie@7f000000 {
+        compatible = "socionext,synquacer-pcie-ecam", "snps,dw-pcie-ecam";
+        device_type = "pci";
+        reg = <0x0 0x7f000000 0x0 0xf00000>;
+        bus-range = <0x0 0xe>;
+        #address-cells = <3>;
+        #size-cells = <2>;
+        ranges = <0x1000000 0x00 0x00010000 0x00 0x7ff00000 0x0 0x00010000>,
+                 <0x2000000 0x00 0x70000000 0x00 0x70000000 0x0 0x0f000000>,
+                 <0x3000000 0x3f 0x00000000 0x3f 0x00000000 0x1 0x00000000>;
+
+        #interrupt-cells = <0x1>;
+        interrupt-map-mask = <0x0 0x0 0x0 0x0>;
+        interrupt-map = <0x0 0x0 0x0 0x0 &gic 0x0 0x0 0x0 182 0x4>;
+        msi-map = <0x0 &its 0x0 0x10000>;
+        dma-coherent;
+    };