diff mbox series

[v3,1/4] dt-bindings: hwmon: Add Aspeed AST2600 PWM/Fan

Message ID 20210118065059.2478078-2-troy_lee@aspeedtech.com
State New
Headers show
Series hwmon: aspeed2600-pwm-tacho: Add driver support | expand

Commit Message

Troy Lee Jan. 18, 2021, 6:50 a.m. UTC
We add binding for supporting a new AST2600 PWM/Fan hwmon driver.

Changes since v2:
 - Fixed yamllint warnings/errors

Changes since v1:
 - dt binding with DT schema format

Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
Reported-by: Rob Herring <robh@kernel.org>
---
 .../hwmon/aspeed,ast2600-pwm-tachometer.yaml  | 131 ++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml

Comments

Andrew Jeffery Jan. 22, 2021, 4:26 a.m. UTC | #1
On Mon, 18 Jan 2021, at 17:20, Troy Lee wrote:
> We add binding for supporting a new AST2600 PWM/Fan hwmon driver.
> 
> Changes since v2:
>  - Fixed yamllint warnings/errors
> 
> Changes since v1:
>  - dt binding with DT schema format
> 
> Signed-off-by: Troy Lee <troy_lee@aspeedtech.com>
> Reported-by: Rob Herring <robh@kernel.org>
> ---
>  .../hwmon/aspeed,ast2600-pwm-tachometer.yaml  | 131 ++++++++++++++++++
>  1 file changed, 131 insertions(+)
>  create mode 100644 
> Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml
> 
> diff --git 
> a/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml
> new file mode 100644
> index 000000000000..fa5340f5a43f
> --- /dev/null
> +++ 
> b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml
> @@ -0,0 +1,131 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: 
> http://devicetree.org/schemas/hwmon/aspeed,ast2600-pwm-tachometer.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ASPEED AST2600 PWM and Fan Tacho controller device driver
> +
> +maintainers:
> +  - Ryan Chen <ryan_chen@aspeedtech.com>
> +
> +description: |
> +  The ASPEED PWM controller can support upto 16 PWM outputs. The 
> ASPEED Fan Tacho
> +  controller can support upto 16 Fan tachometer inputs.
> +  There can be upto 16 fans supported. Each fan can have one PWM 
> output and
> +  one Fan tach inputs.
> +
> +properties:
> +  compatible:
> +    const: aspeed,ast2600-pwm-tachometer
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +  "#cooling-cells":
> +    const: 2
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +patternProperties:
> +  "^fan@[0-9a-f]$":
> +    type: object
> +    description:
> +      Under fan subnode there can upto 16 child nodes, with each child 
> node
> +      representing a fan. There are 16 fans each fan can have one PWM 
> port and one
> +      Fan tach inputs.
> +      For PWM port can be configured cooling-levels to create cooling 
> device.
> +      Cooling device could be bound to a thermal zone for the thermal 
> control.
> +
> +    properties:
> +      reg:
> +        minimum: 0
> +        maximum: 15
> +        description:
> +          This property identify the PWM control channel of this fan.
> +
> +      fan-tach-ch:
> +        $ref: /schemas/types.yaml#/definitions/uint8
> +        minimum: 0
> +        maximum: 15
> +        description:
> +          This property identify the fan tach input channel.
> +
> +      pulses-per-revolution:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        default: 2
> +        minimum: 1
> +        description:
> +          Specify tacho pulse per revolution of the fan.
> +
> +      cooling-levels:
> +        description:
> +          PWM duty cycle values in a range from 0 to 255
> +          which correspond to thermal cooling states.
> +
> +      aspeed,pwm-freq-hz:
> +        default: 25000
> +        minimum: 24
> +        maximum: 780000
> +        description:
> +          Specify the frequency of PWM.

What about using 'bus-frequency' instead?

> +
> +      aspeed,inverse-pin:
> +        type: boolean
> +        description:
> +          Inverse PWM output signal.

What's the benefit? I know the hardware provides the function, but do we need to expose it?

> +
> +      aspeed,falling-point:
> +        $ref: /schemas/types.yaml#/definitions/uint8
> +        default: 10

I feel like it probably shouldn't have a default value.

> +        description:
> +          Initialize the pulse width.

Then can we make the property name a bit more intuitive? 'pwm-duty'? Alternatively, [1] calls the duty "cooling-levels", can we use something in that vein instead?

[1] Documentation/devicetree/bindings/hwmon/pwm-fan.txt

Andrew
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml
new file mode 100644
index 000000000000..fa5340f5a43f
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-pwm-tachometer.yaml
@@ -0,0 +1,131 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/aspeed,ast2600-pwm-tachometer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED AST2600 PWM and Fan Tacho controller device driver
+
+maintainers:
+  - Ryan Chen <ryan_chen@aspeedtech.com>
+
+description: |
+  The ASPEED PWM controller can support upto 16 PWM outputs. The ASPEED Fan Tacho
+  controller can support upto 16 Fan tachometer inputs.
+  There can be upto 16 fans supported. Each fan can have one PWM output and
+  one Fan tach inputs.
+
+properties:
+  compatible:
+    const: aspeed,ast2600-pwm-tachometer
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  "#cooling-cells":
+    const: 2
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+patternProperties:
+  "^fan@[0-9a-f]$":
+    type: object
+    description:
+      Under fan subnode there can upto 16 child nodes, with each child node
+      representing a fan. There are 16 fans each fan can have one PWM port and one
+      Fan tach inputs.
+      For PWM port can be configured cooling-levels to create cooling device.
+      Cooling device could be bound to a thermal zone for the thermal control.
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 15
+        description:
+          This property identify the PWM control channel of this fan.
+
+      fan-tach-ch:
+        $ref: /schemas/types.yaml#/definitions/uint8
+        minimum: 0
+        maximum: 15
+        description:
+          This property identify the fan tach input channel.
+
+      pulses-per-revolution:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        default: 2
+        minimum: 1
+        description:
+          Specify tacho pulse per revolution of the fan.
+
+      cooling-levels:
+        description:
+          PWM duty cycle values in a range from 0 to 255
+          which correspond to thermal cooling states.
+
+      aspeed,pwm-freq-hz:
+        default: 25000
+        minimum: 24
+        maximum: 780000
+        description:
+          Specify the frequency of PWM.
+
+      aspeed,inverse-pin:
+        type: boolean
+        description:
+          Inverse PWM output signal.
+
+      aspeed,falling-point:
+        $ref: /schemas/types.yaml#/definitions/uint8
+        default: 10
+        description:
+          Initialize the pulse width.
+
+    required:
+      - fan-tach-ch
+      - reg
+
+    additionalProperties: true
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    pwm_tacho: pwm-tacho-controller@1e610000 {
+        compatible = "aspeed,ast2600-pwm-tachometer";
+        #address-cells = <1>;
+        #size-cells = <0>;
+        reg = <0x1e610000 0x100>;
+
+        fan@1 {
+            reg = <0x00>;
+            aspeed,pwm-freq-hz = <25000>;
+            cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
+            fan-tach-ch = /bits/ 8 <0x00>;
+            pulses-per-revolution = <2>;
+        };
+
+        fan@2 {
+            reg = <0x01>;
+            aspeed,pwm-freq-hz = <25000>;
+            cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
+            fan-tach-ch = /bits/ 8 <0x01>;
+            pulses-per-revolution = <2>;
+        };
+    };
+...