[PATCH v3 3/4] dt-bindings: hwmon: Add binding for max6639

[PATCH v3 3/4] dt-bindings: hwmon: Add binding for max6639

[Marcello Sylvester Bauer]

Add Devicetree binding documentation for Maxim MAX6639 temperature
monitor with PWM fan-speed controller.

The devicetree documentation for the SD3078 device tree.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
---
 .../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..7093cbeba44b
--- /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@antcom.de>
+
+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
+  - "channel@0"
+  - "channel@1"
+
+additionalProperties: false
+
+patternProperties:
+  "^channel@[0-1]$":
+    type: object
+    description: |
+      Represents the two fans and their specific configuration.
+
+    properties:
+      reg:
+        description: |
+          The fan number.
+        items:
+          minimum: 0
+          maximum: 1
+
+      pwm-polarity:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        enum: [0, 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]
+        description:
+          Value specifying the number of pulses per revolution of the controlled
+          FAN.
+
+      rpm-range:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        enum: [2000, 4000, 8000, 16000]
+        description:
+          Scales the tachometer counter by setting the maximum (full-scale) value
+          of the RPM range.
+
+    required:
+      - reg
+      - pwm-polarity
+      - pulses-per-revolution
+      - rpm-range
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      max6639@10 {
+        compatible = "maxim,max6639";
+        reg = <0x10>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        channel@0 {
+          reg = <0x0>;
+          pwm-polarity = <1>;
+          pulses-per-revolution = <2>;
+          rpm-range = <4000>;
+        };
+
+        channel@1 {
+          reg = <0x1>;
+          pwm-polarity = <1>;
+          pulses-per-revolution = <2>;
+          rpm-range = <4000>;
+        };
+      };
+    };
+...
-- 
2.33.1

Re: [PATCH v3 3/4] dt-bindings: hwmon: Add binding for max6639

[Guenter Roeck]

On Wed, Jan 19, 2022 at 10:53:54AM +0100, Marcello Sylvester Bauer wrote:
> Add Devicetree binding documentation for Maxim MAX6639 temperature
> monitor with PWM fan-speed controller.
> 
> The devicetree documentation for the SD3078 device tree.
> 
> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> ---
>  .../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..7093cbeba44b
> --- /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@antcom.de>
> +
> +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
> +  - "channel@0"
> +  - "channel@1"
> +
> +additionalProperties: false
> +
> +patternProperties:
> +  "^channel@[0-1]$":
> +    type: object
> +    description: |
> +      Represents the two fans and their specific configuration.
> +
> +    properties:
> +      reg:
> +        description: |
> +          The fan number.
> +        items:
> +          minimum: 0
> +          maximum: 1
> +
> +      pwm-polarity:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        enum: [0, 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]
> +        description:
> +          Value specifying the number of pulses per revolution of the controlled
> +          FAN.
> +

I think the above two properties should be optional.
pulses-per-revolution is 2 for almost all fans out there,
and pwm polarity is positive almost all the time.

> +      rpm-range:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        enum: [2000, 4000, 8000, 16000]
> +        description:
> +          Scales the tachometer counter by setting the maximum (full-scale) value
> +          of the RPM range.
> +
Isn't this the maximum rpm ? Using the term "range" seems to be
a bit misleading.

> +    required:
> +      - reg
> +      - pwm-polarity
> +      - pulses-per-revolution
> +      - rpm-range
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      max6639@10 {
> +        compatible = "maxim,max6639";
> +        reg = <0x10>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        channel@0 {
> +          reg = <0x0>;
> +          pwm-polarity = <1>;
> +          pulses-per-revolution = <2>;
> +          rpm-range = <4000>;
> +        };
> +
> +        channel@1 {
> +          reg = <0x1>;
> +          pwm-polarity = <1>;
> +          pulses-per-revolution = <2>;
> +          rpm-range = <4000>;
> +        };
> +      };
> +    };
> +...

Re: [PATCH v3 3/4] dt-bindings: hwmon: Add binding for max6639

[sylv]

On Mon, 2022-01-24 at 21:08 -0800, Guenter Roeck wrote:
> On Wed, Jan 19, 2022 at 10:53:54AM +0100, Marcello Sylvester Bauer
> wrote:
> > Add Devicetree binding documentation for Maxim MAX6639 temperature
> > monitor with PWM fan-speed controller.
> > 
> > The devicetree documentation for the SD3078 device tree.
> > 
> > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > ---
> >  .../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..7093cbeba44b
> > --- /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@antcom.de>
> > +
> > +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
> > +  - "channel@0"
> > +  - "channel@1"
> > +
> > +additionalProperties: false
> > +
> > +patternProperties:
> > +  "^channel@[0-1]$":
> > +    type: object
> > +    description: |
> > +      Represents the two fans and their specific configuration.
> > +
> > +    properties:
> > +      reg:
> > +        description: |
> > +          The fan number.
> > +        items:
> > +          minimum: 0
> > +          maximum: 1
> > +
> > +      pwm-polarity:
> > +        $ref: /schemas/types.yaml#/definitions/uint32
> > +        enum: [0, 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]
> > +        description:
> > +          Value specifying the number of pulses per revolution of
> > the controlled
> > +          FAN.
> > +
> 
> I think the above two properties should be optional.
> pulses-per-revolution is 2 for almost all fans out there,
> and pwm polarity is positive almost all the time.

makes sense. I guess I'll keep the default values like before and
also set rpm-range (resp. rpm-max) to 4000.

> 
> > +      rpm-range:
> > +        $ref: /schemas/types.yaml#/definitions/uint32
> > +        enum: [2000, 4000, 8000, 16000]
> > +        description:
> > +          Scales the tachometer counter by setting the maximum
> > (full-scale) value
> > +          of the RPM range.
> > +
> Isn't this the maximum rpm ? Using the term "range" seems to be
> a bit misleading.

Yeah, the data sheet explicitly calls this register "rpm fan range".
But since this is not a vendor specific property and the purpose is
to set a maximum rpm value, it should rather be called "rpm-max".

Thanks!

Marcello

> 
> > +    required:
> > +      - reg
> > +      - pwm-polarity
> > +      - pulses-per-revolution
> > +      - rpm-range
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      max6639@10 {
> > +        compatible = "maxim,max6639";
> > +        reg = <0x10>;
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        channel@0 {
> > +          reg = <0x0>;
> > +          pwm-polarity = <1>;
> > +          pulses-per-revolution = <2>;
> > +          rpm-range = <4000>;
> > +        };
> > +
> > +        channel@1 {
> > +          reg = <0x1>;
> > +          pwm-polarity = <1>;
> > +          pulses-per-revolution = <2>;
> > +          rpm-range = <4000>;
> > +        };
> > +      };
> > +    };
> > +...