From 6b1bb53579b0a46c7a2467fffcd23e54e844ff41 Mon Sep 17 00:00:00 2001
From: Chris Packham <chris.packham@alliedtelesis.co.nz>
Date: Tue, 23 Jul 2024 10:17:35 +1200
Subject: [PATCH] dt-bindings: hwmon: Add adt7475 fan/pwm properties

Add fan child nodes that allow describing the connections for the
ADT7475 to the fans it controls. This also allows setting some
initial values for the pwm duty cycle and frequency.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240722221737.3407958-2-chris.packham@alliedtelesis.co.nz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 .../devicetree/bindings/hwmon/adt7475.yaml    | 35 ++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/hwmon/adt7475.yaml b/Documentation/devicetree/bindings/hwmon/adt7475.yaml
index 051c976ab711f..df2b5b889e4df 100644
--- a/Documentation/devicetree/bindings/hwmon/adt7475.yaml
+++ b/Documentation/devicetree/bindings/hwmon/adt7475.yaml
@@ -51,6 +51,24 @@ properties:
       enum: [0, 1]
       default: 1
 
+  "#pwm-cells":
+    const: 4
+    description: |
+      Number of cells in a PWM specifier.
+      - 0: The PWM channel
+      - 1: The PWM period in nanoseconds
+           - 90909091 (11 Hz)
+           - 71428571 (14 Hz)
+           - 45454545 (22 Hz)
+           - 34482759 (29 Hz)
+           - 28571429 (35 Hz)
+           - 22727273 (44 Hz)
+           - 17241379 (58 Hz)
+           - 11363636 (88 Hz)
+           - 44444 (22 kHz)
+      - 2: PWM flags 0 or PWM_POLARITY_INVERTED
+      - 3: The default PWM duty cycle in nanoseconds
+
 patternProperties:
   "^adi,bypass-attenuator-in[0-4]$":
     description: |
@@ -81,6 +99,10 @@ patternProperties:
       - smbalert#
       - gpio
 
+  "^fan-[0-9]+$":
+    $ref: fan-common.yaml#
+    unevaluatedProperties: false
+
 required:
   - compatible
   - reg
@@ -89,11 +111,12 @@ additionalProperties: false
 
 examples:
   - |
+    #include <dt-bindings/pwm/pwm.h>
     i2c {
       #address-cells = <1>;
       #size-cells = <0>;
 
-      hwmon@2e {
+      pwm: hwmon@2e {
         compatible = "adi,adt7476";
         reg = <0x2e>;
         adi,bypass-attenuator-in0 = <1>;
@@ -101,5 +124,15 @@ examples:
         adi,pwm-active-state = <1 0 1>;
         adi,pin10-function = "smbalert#";
         adi,pin14-function = "tach4";
+        #pwm-cells = <4>;
+
+        /* PWMs at 22.5 kHz frequency, 50% duty*/
+        fan-0 {
+          pwms = <&pwm 0 44444 0 22222>;
+        };
+
+        fan-1 {
+          pwms = <&pwm 2 44444 0 22222>;
+        };
       };
     };
-- 
2.50.1