Hi Rob,

On 1/8/2020 2:19 am, Rob Herring wrote:

On Tue, Jul 28, 2020 at 04:52:12PM +0800, Rahul Tanwar wrote:

quoted

Intel's LGM(Lightning Mountain) SoC contains a PWM fan controller
which is only used to control the fan attached to the system. This
PWM controller does not have any other consumer other than fan.
Add DT bindings documentation for this PWM fan controller.

Signed-off-by: Rahul Tanwar <redacted>
---
 .../devicetree/bindings/pwm/intel,lgm-pwm.yaml     | 54 ++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml b/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml
new file mode 100644
index 000000000000..9879972470dc
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/intel,lgm-pwm.yaml

@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/intel,lgm-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LGM SoC PWM fan controller
+
+maintainers:
+  - Rahul Tanwar <rahul.tanwar@intel.com>
+
+properties:
+  compatible:
+    const: intel,lgm-pwm
+
+  reg:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  intel,fan-wire:
+    $ref: '/schemas/types.yaml#/definitions/uint32'
+    description: Specifies fan mode. Default when unspecified is 2.
+
+  intel,max-rpm:
+    $ref: '/schemas/types.yaml#/definitions/uint32'
+    description:
+      Specifies maximum RPM of fan attached to the system.
+      Default when unspecified is 4000.

Again, these are properties of a fan, not the pwm controller. They 
belong in a fan node.

Our PWM controller is actually a PWM fan controller dedicated for
controlling fan. I am looking for some suggestions from you on how
to handle fan related optional properties in such a scenario.

Should i create a separate child node for fan with PWM node being
the parent? Is that what you are suggesting? Thanks.

Regards,
Rahul