[PATCH v5 1/2] dt-bindings: hwmon: Add starfive,jhb100-pwm-fan

[Changhuang Liang]

Add a binding for the StarFive JHB100 PWM fan controller. The controller
has a hardware tachometer block with 16 tachometer inputs, while fan
speed is controlled through 8 PWM channels supplied by an external PWM
controller.

One PWM channel can drive up to two fans, so each fan-N child node
references one PWM channel and lists the tachometer inputs wired to the
fans it drives.

Signed-off-by: Changhuang Liang <changhuang.liang@xxxxxxxxxxxxxxxx>
---
 .../hwmon/starfive,jhb100-pwm-fan.yaml        | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/starfive,jhb100-pwm-fan.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/starfive,jhb100-pwm-fan.yaml b/Documentation/devicetree/bindings/hwmon/starfive,jhb100-pwm-fan.yaml
new file mode 100644
index 000000000000..b05789867c0e
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/starfive,jhb100-pwm-fan.yaml
@@ -0,0 +1,87 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/starfive,jhb100-pwm-fan.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: StarFive JHB100 PWM Fan Controller
+
+maintainers:
+  - Changhuang Liang <changhuang.liang@xxxxxxxxxxxxxxxx>
+
+description:
+  The StarFive JHB100 fan controller uses a hardware tachometer block with
+  16 tachometer inputs to measure fan speed. Fan speed is controlled through
+  8 PWM channels supplied by an external PWM controller, and one PWM channel
+  can drive up to two fans. Each fan child node references the PWM channel
+  driving the fan(s) and lists the tachometer inputs wired to them.
+
+properties:
+  compatible:
+    const: starfive,jhb100-pwm-fan
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+patternProperties:
+  "^fan-[0-7]$":
+    $ref: fan-common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      pulses-per-revolution:
+        minimum: 1
+        default: 2
+
+      tach-ch:
+        description:
+          The tachometer input(s) wired to the fan(s) driven by the PWM
+          channel. One PWM channel can drive up to two fans.
+        minItems: 1
+        maxItems: 2
+        items:
+          maximum: 15
+
+    required:
+      - pwms
+      - tach-ch
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    fan-controller@11be0000 {
+        compatible = "starfive,jhb100-pwm-fan";
+        reg = <0x11be0000 0x400>;
+        interrupts = <128>;
+        clocks = <&per2crg 33>;
+        resets = <&per2crg 5>;
+
+        fan-0 {
+            pwms = <&pwm0 0 40000 0>;
+            tach-ch = /bits/ 8 <0x0 0x8>;
+            pulses-per-revolution = <2>;
+        };
+
+        fan-1 {
+            pwms = <&pwm1 0 40000 0>;
+            tach-ch = /bits/ 8 <0x1 0x9>;
+        };
+    };
+...
-- 
2.25.1