Re: [PATCH 1/2] dt-bindings: hwmon: Add binding for max6639

From: Krzysztof Kozlowski
Date: Thu Sep 22 2022 - 02:35:09 EST


On 22/09/2022 07:07, Naresh Solanki wrote:
> From: Marcello Sylvester Bauer <sylv@xxxxxxx>
>
> Add Devicetree binding documentation for Maxim MAX6639 temperature
> monitor with PWM fan-speed controller.
>
> Signed-off-by: Marcello Sylvester Bauer <sylv@xxxxxxx>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
> ---
> .../bindings/hwmon/maxim,max6639.yaml | 112 ++++++++++++++++++
> 1 file changed, 112 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
>
> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
> new file mode 100644
> index 000000000000..c845fb989af2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max6639.yaml
> @@ -0,0 +1,112 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/hwmon/maxim,max6639.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim max6639
> +
> +maintainers:
> + - Roland Stigge <stigge@xxxxxxxxx>

Ack from Roland is needed here.

> +
> +description: |
> + The MAX6639 is a 2-channel temperature monitor with dual, automatic, PWM
> + fan-speed controller. It monitors its own temperature and one external
> + diode-connected transistor or the temperatures of two external diode-connected
> + transistors, typically available in CPUs, FPGAs, or GPUs.
> +
> + Datasheets:
> + https://datasheets.maximintegrated.com/en/ds/MAX6639-MAX6639F.pdf
> +
> +properties:
> + compatible:
> + enum:
> + - maxim,max6639
> +
> + reg:
> + maxItems: 1
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +required:
> + - compatible
> + - reg
> + - "fan@0"
> + - "fan@1"
> +
> +additionalProperties: false
> +
> +patternProperties:

This goes after properties.

> + "^fan@[0-1]$":
> + type: object
> + description: |
> + Represents the two fans and their specific configuration.
> +
> + properties:
> + reg:
> + description: |
> + The fan number.
> + items:

Skip items.

> + minimum: 0
> + maximum: 1
> +
> + pwm-polarity:

Why is this property of fan, not of PWM source?

> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1]

type: boolean

> + default: 1
> + description:
> + PWM output is low at 100% duty cycle when this bit is set to zero. PWM
> + output is high at 100% duty cycle when this bit is set to 1.
> +
> + pulses-per-revolution:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [1, 2, 3, 4]
> + default: 2
> + description:
> + Value specifying the number of pulses per revolution of the controlled
> + FAN.
> +
> + maxim,rpm-range:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [2000, 4000, 8000, 16000]
> + default: 4000
> + description:
> + Scales the tachometer counter by setting the maximum (full-scale) value
> + of the RPM range for max6639.
> +
> + required:
> + - reg
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + max6639@10 {

Node names should be generic.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

> + compatible = "maxim,max6639";
> + reg = <0x10>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + fan@0 {
> + reg = <0x0>;
> + pwm-polarity = <1>;
> + pulses-per-revolution = <2>;
> + maxim,rpm-range = <4000>;
> + };
> +
> + fan@1 {
> + reg = <0x1>;
> + pwm-polarity = <1>;
> + pulses-per-revolution = <2>;
> + maxim,rpm-range = <4000>;
> + };
> + };
> + };
> +...

Best regards,
Krzysztof