dt-bindings: Add a binding for Mediatek SCP

Add a DT binding documentation of SCP for the
MT8183 SoC from Mediatek.

Signed-off-by: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191112110330.179649-2-pihsun@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
new file mode 100644 (file)
index 0000000..3ba668b
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
@@ -0,0 +1,36 @@
+Mediatek SCP Bindings
+----------------------------------------
+
+This binding provides support for ARM Cortex M4 Co-processor found on some
+Mediatek SoCs.
+
+Required properties:
+- compatible           Should be "mediatek,mt8183-scp"
+- reg                  Should contain the address ranges for the two memory
+                       regions, SRAM and CFG.
+- reg-names            Contains the corresponding names for the two memory
+                       regions. These should be named "sram" & "cfg".
+- clocks               Clock for co-processor (See: ../clock/clock-bindings.txt)
+- clock-names          Contains the corresponding name for the clock. This
+                       should be named "main".
+
+Subnodes
+--------
+
+Subnodes of the SCP represent rpmsg devices. The names of the devices are not
+important. The properties of these nodes are defined by the individual bindings
+for the rpmsg devices - but must contain the following property:
+
+- mtk,rpmsg-name       Contains the name for the rpmsg device. Used to match
+                       the subnode to rpmsg device announced by SCP.
+
+Example:
+
+       scp: scp@10500000 {
+               compatible = "mediatek,mt8183-scp";
+               reg = <0 0x10500000 0 0x80000>,
+                     <0 0x105c0000 0 0x5000>;
+               reg-names = "sram", "cfg";
+               clocks = <&infracfg CLK_INFRA_SCPSYS>;
+               clock-names = "main";
+       };