dt-bindings: bus: Add documentation for Tegra210 ACONNECT

[cascardo/linux.git] / Documentation / devicetree / bindings / bus / nvidia,tegra210-aconnect.txt

diff --git a/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt b/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt
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+NVIDIA Tegra ACONNECT Bus
+
+The Tegra ACONNECT bus is an AXI switch which is used to connnect various
+components inside the Audio Processing Engine (APE). All CPU accesses to
+the APE subsystem go through the ACONNECT via an APB to AXI wrapper.
+
+Required properties:
+- compatible: Must be "nvidia,tegra210-aconnect".
+- clocks: Must contain the entries for the APE clock (TEGRA210_CLK_APE),
+  and APE interface clock (TEGRA210_CLK_APB2APE).
+- clock-names: Must contain the names "ape" and "apb2ape" for the corresponding
+  'clocks' entries.
+- power-domains: Must contain a phandle that points to the audio powergate
+  (namely 'aud') for Tegra210.
+- #address-cells: The number of cells used to represent physical base addresses
+  in the aconnect address space. Should be 1.
+- #size-cells: The number of cells used to represent the size of an address
+  range in the aconnect address space. Should be 1.
+- ranges: Mapping of the aconnect address space to the CPU address space.
+
+All devices accessed via the ACONNNECT are described by child-nodes.
+
+Example:
+
+       aconnect@702c0000 {
+               compatible = "nvidia,tegra210-aconnect";
+               clocks = <&tegra_car TEGRA210_CLK_APE>,
+                        <&tegra_car TEGRA210_CLK_APB2APE>;
+               clock-names = "ape", "apb2ape";
+               power-domains = <&pd_audio>;
+
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges = <0x702c0000 0x0 0x702c0000 0x00040000>;
+
+               status = "disabled";
+
+               child1 {
+                       ...
+               };
+
+               child2 {
+                       ...
+               };
+       };