devicetree: bindings: phy: Document ipq806x dwc3 qcom phy

Document dwc3 qcom phy hs and ss phy bindings needed to correctly
inizialize and use usb on ipq806x SoC.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200717131635.11076-2-ansuelsmth@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/qcom,ipq806x-usb-phy-hs.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/qcom,ipq806x-usb-phy-hs.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm ipq806x usb DWC3 HS PHY CONTROLLER
+
+maintainers:
+  - Ansuel Smith <ansuelsmth@gmail.com>
+
+description:
+  DWC3 PHY nodes are defined to describe on-chip Synopsis Physical layer
+  controllers used in ipq806x. Each DWC3 PHY controller should have its
+  own node.
+
+properties:
+  compatible:
+    const: qcom,ipq806x-usb-phy-hs
+
+  "#phy-cells":
+    const: 0
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      - const: ref
+      - const: xo
+
+required:
+  - compatible
+  - "#phy-cells"
+  - reg
+  - clocks
+  - clock-names
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,gcc-ipq806x.h>
+
+    hs_phy_0: phy@110f8800 {
+      compatible = "qcom,ipq806x-usb-phy-hs";
+      reg = <0x110f8800 0x30>;
+      clocks = <&gcc USB30_0_UTMI_CLK>;
+      clock-names = "ref";
+      #phy-cells = <0>;
+    };

Documentation/devicetree/bindings/phy/qcom,ipq806x-usb-phy-ss.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/qcom,ipq806x-usb-phy-ss.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm ipq806x usb DWC3 SS PHY CONTROLLER
+
+maintainers:
+  - Ansuel Smith <ansuelsmth@gmail.com>
+
+description:
+  DWC3 PHY nodes are defined to describe on-chip Synopsis Physical layer
+  controllers used in ipq806x. Each DWC3 PHY controller should have its
+  own node.
+
+properties:
+  compatible:
+    const: qcom,ipq806x-usb-phy-ss
+
+  "#phy-cells":
+    const: 0
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      - const: ref
+      - const: xo
+
+  qcom,rx-eq:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Override value for rx_eq.
+    default: 4
+    maximum: 7
+
+  qcom,tx-deamp-3_5db:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Override value for transmit preemphasis.
+    default: 23
+    maximum: 63
+
+  qcom,mpll:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Override value for mpll.
+    default: 0
+    maximum: 7
+
+required:
+  - compatible
+  - "#phy-cells"
+  - reg
+  - clocks
+  - clock-names
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,gcc-ipq806x.h>
+
+    ss_phy_0: phy@110f8830 {
+      compatible = "qcom,ipq806x-usb-phy-ss";
+      reg = <0x110f8830 0x30>;
+      clocks = <&gcc USB30_0_MASTER_CLK>;
+      clock-names = "ref";
+      #phy-cells = <0>;
+    };