[PATCH v2 1/3] dt-bindings: clocks: add binding for voltage-controlled-oscillators

[Heiko Stuebner <heiko@sntech.de>]

In contrast to fixed clocks that are described as ungateable, boards
sometimes use additional oscillators for things like PCIe reference
clocks, that need actual supplies to get enabled and enable-gpios to be
toggled for them to work.

This adds a binding for such oscillators that are not configurable
themself, but need to handle supplies for them to work.

In schematics they often can be seen as

         ----------------
Enable - | 100MHz,3.3V, | - VDD
         |    3225      |
   GND - |              | - OUT
         ----------------

or similar. The enable pin might be separate but can also just be tied
to the vdd supply, hence it is optional in the binding.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 .../bindings/clock/voltage-oscillator.yaml    | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/voltage-oscillator.yaml

diff --git a/Documentation/devicetree/bindings/clock/voltage-oscillator.yaml b/Documentation/devicetree/bindings/clock/voltage-oscillator.yaml
new file mode 100644
index 0000000000000..8bff6b0fd582e
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/voltage-oscillator.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/voltage-oscillator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Voltage controlled oscillator
+
+maintainers:
+  - Heiko Stuebner <heiko@sntech.de>
+
+properties:
+  compatible:
+    const: voltage-oscillator
+
+  "#clock-cells":
+    const: 0
+
+  clock-frequency: true
+
+  clock-output-names:
+    maxItems: 1
+
+  enable-gpios:
+    description:
+      Contains a single GPIO specifier for the GPIO that enables and disables
+      the oscillator.
+    maxItems: 1
+
+  vdd-supply:
+    description: handle of the regulator that provides the supply voltage
+
+required:
+  - compatible
+  - "#clock-cells"
+  - clock-frequency
+  - vdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    voltage-oscillator {
+      compatible = "voltage-oscillator";
+      #clock-cells = <0>;
+      clock-frequency = <1000000000>;
+      vdd-supply = <&reg_vdd>;
+    };
+...
-- 
2.39.2