Re: [PATCH v3 2/3] dt-bindings: pwm: Document clk based PWM controller

On 1/21/22 2:34 AM, Krzysztof Kozlowski wrote:

On Thu, 20 Jan 2022 at 17:15, Nikita Travkin [off-list ref] wrote:

quoted

Add YAML devicetree binding for clk based PWM controller

Signed-off-by: Nikita Travkin <redacted>
--
Changes in v2:
 - fix the file name.
---
 .../devicetree/bindings/pwm/clk-pwm.yaml      | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/clk-pwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/clk-pwm.yaml b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml
new file mode 100644
index 000000000000..4fb2c1baaad4
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml

@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/clk-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Clock based PWM controller
+
+maintainers:
+  - Nikita Travkin <nikita@trvn.ru>
+
+description: |
+  Some systems have clocks that can be exposed to external devices.
+  (e.g. by muxing them to GPIO pins)
+  It's often possible to control duty-cycle of such clocks which makes them
+  suitable for generating PWM signal.
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    const: clk-pwm
+
+  clocks:
+    description: Clock used to generate the signal.
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+unevaluatedProperties: false
+
+required:
+  - clocks
+
+examples:
+  - |
+    pwm-flash {

Node names should be generic (see devicetree specification), so just "pwm".

And then what will you do if you have two clock-based pwms?

--Sean