Re: [PATCH v7 1/3] dt-bindings: mfd: Add Gateworks System Controller bindings

[Rob Herring]

On Fri, Mar 20, 2020 at 01:35:48PM -0700, Tim Harvey wrote:
> This patch adds documentation of device-tree bindings for the
> Gateworks System Controller (GSC).
> 
> Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> ---
> v7:
>  - change divider from mili-ohms to ohms
>  - add constraints for voltage divider and offset
>  - remove unnecessary ref for offset
>  - renamed fan to fan-controller and changed base prop to reg
> 
> v6:
>  - fix typo
>  - drop invalid description from #interrupt-cells property
>  - fix adc pattern property
>  - add unit suffix
>  - replace hwmon/adc with adc/channel
>  - changed adc type to mode and enum int
>  - add unit suffix and drop ref for voltage-divider
>  - moved fan to its own subnode with base register
> 
> v5:
>  - resolve dt_binding_check issues
> 
> v4:
>  - move to using pwm<n>_auto_point<m>_{pwm,temp} for FAN PWM
>  - remove unncessary resolution/scaling properties for ADCs
>  - update to yaml
>  - remove watchdog
> 
> v3:
>  - replaced _ with -
>  - remove input bindings
>  - added full description of hwmon
>  - fix unit address of hwmon child nodes
> ---
>  .../devicetree/bindings/mfd/gateworks-gsc.yaml     | 173 +++++++++++++++++++++
>  1 file changed, 173 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml b/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
> new file mode 100644
> index 00000000..0457137
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
> @@ -0,0 +1,173 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/gateworks-gsc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Gateworks System Controller multi-function device
> +
> +description: |
> +  The GSC is a Multifunction I2C slave device with the following submodules:
> +   - Watchdog Timer
> +   - GPIO
> +   - Pushbutton controller
> +   - Hardware Monitor with ADC's for temperature and voltage rails and
> +     fan controller
> +
> +maintainers:
> +  - Tim Harvey <tharvey@xxxxxxxxxxxxx>
> +  - Robert Jones <rjones@xxxxxxxxxxxxx>
> +
> +properties:
> +  $nodename:
> +    pattern: "gsc@[0-9a-f]{1,2}"
> +  compatible:
> +    const: gw,gsc
> +
> +  reg:
> +    description: I2C device address
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  interrupt-controller: true
> +
> +  "#interrupt-cells":
> +    const: 1
> +
> +  adc:
> +    type: object
> +    description: Optional Hardware Monitoring module
> +
> +    properties:
> +      compatible:
> +        const: gw,gsc-adc
> +
> +      "#address-cells":
> +        const: 1
> +
> +      "#size-cells":
> +        const: 0
> +
> +    patternProperties:
> +      "^channel@[0-9]+$":
> +        type: object
> +        description: |
> +          Properties for a single ADC which can report cooked values
> +          (ie temperature sensor based on thermister), raw values
> +          (ie voltage rail with a pre-scaling resistor divider).
> +
> +        properties:
> +          reg:
> +            description: Register of the ADC
> +            maxItems: 1
> +
> +          label:
> +            description: Name of the ADC input
> +
> +          gw,mode:
> +            description: |
> +              conversion mode:
> +                0 - temperature, in C*10
> +                1 - pre-scaled voltage value
> +                2 - scaled voltage based on an optional resistor divider
> +                    and optional offset
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +            enum: [0, 1, 2]
> +
> +          gw,voltage-divider-ohms:
> +            description: values of resistors for divider on raw ADC input
> +            maxItems: 2
> +            items:
> +             minimum: 1000
> +             maximum: 1000000
> +
> +          gw,voltage-offset-microvolt:
> +            description: |
> +              A positive voltage offset to apply to a raw ADC
> +              (ie to compensate for a diode drop).
> +            minimum: 0
> +            maximum: 1000000
> +
> +        required:
> +          - gw,mode
> +          - reg
> +          - label
> +
> +    required:
> +      - compatible
> +      - "#address-cells"
> +      - "#size-cells"
> +
> +  fan-controller:
> +    type: object
> +    description: Optional FAN controller
> +
> +    properties:
> +      compatible:
> +        const: gw,gsc-fan
> +
> +      reg:
> +        description: The fan controller base address
> +        maxItems: 1
> +
> +    required:
> +      - compatible
> +      - reg
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - interrupt-controller
> +  - "#interrupt-cells"
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        gsc@20 {
> +            compatible = "gw,gsc";
> +            reg = <0x20>;
> +            interrupt-parent = <&gpio1>;
> +            interrupts = <4 GPIO_ACTIVE_LOW>;
> +            interrupt-controller;
> +            #interrupt-cells = <1>;
> +
> +            adc {
> +                compatible = "gw,gsc-adc";
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                channel@0 { /* A0: Board Temperature */
> +                    reg = <0x00>;
> +                    label = "temp";
> +                    gw,mode = <0>;
> +                };
> +
> +                channel@2 { /* A1: Input Voltage (raw ADC) */
> +                    reg = <0x02>;
> +                    label = "vdd_vin";
> +                    gw,mode = <1>;
> +                    gw,voltage-divider-ohms = <22100 1000>;
> +                    gw,voltage-offset-microvolt = <800000>;
> +                };
> +
> +                channel@b { /* A2: Battery voltage */
> +                    reg = <0x0b>;
> +                    label = "vdd_bat";
> +                    gw,mode = <1>;
> +                };
> +            };
> +
> +            fan-controller {

fan-controller@2c

(and the schema will need to be changed either to the above or a 
pattern)

With that,

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

> +                compatible = "gw,gsc-fan";
> +                reg = <0x2c>;
> +            };
> +        };
> +    };
> -- 
> 2.7.4
>