dt-bindings: clock: Add SC8180x GCC binding

Add devicetree binding for the global clock controller found in the
Qualcomm SC8180x platform.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210126043155.1847823-1-bjorn.andersson@linaro.orgSigned-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/qcom,gcc-sc8180x.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/qcom,gcc-sc8180x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Global Clock & Reset Controller Binding for SC8180x
+
+maintainers:
+  - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+description: |
+  Qualcomm global clock control module which supports the clocks, resets and
+  power domains on SC8180x.
+
+  See also:
+  - dt-bindings/clock/qcom,gcc-sc8180x.h
+
+properties:
+  compatible:
+    const: qcom,gcc-sc8180x
+
+  clocks:
+    items:
+      - description: Board XO source
+      - description: Board active XO source
+      - description: Sleep clock source
+
+  clock-names:
+    items:
+      - const: bi_tcxo
+      - const: bi_tcxo_ao
+      - const: sleep_clk
+
+  '#clock-cells':
+    const: 1
+
+  '#reset-cells':
+    const: 1
+
+  '#power-domain-cells':
+    const: 1
+
+  reg:
+    maxItems: 1
+
+  protected-clocks:
+    description:
+      Protected clock specifier list as per common clock binding.
+
+required:
+  - compatible
+  - clocks
+  - clock-names
+  - reg
+  - '#clock-cells'
+  - '#reset-cells'
+  - '#power-domain-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,rpmh.h>
+    clock-controller@100000 {
+      compatible = "qcom,gcc-sc8180x";
+      reg = <0x00100000 0x1f0000>;
+      clocks = <&rpmhcc RPMH_CXO_CLK>,
+               <&rpmhcc RPMH_CXO_CLK_A>,
+               <&sleep_clk>;
+      clock-names = "bi_tcxo", "bi_tcxo_ao", "sleep_clk";
+      #clock-cells = <1>;
+      #reset-cells = <1>;
+      #power-domain-cells = <1>;
+    };
+...