Re: [PATCH v3 2/2] dt-bindings: pinctrl: intel: Add for new SoC

[Rob Herring <robh@kernel.org>]

On Tue, Nov 05, 2019 at 02:49:43PM +0800, Rahul Tanwar wrote:
> Add dt bindings document for pinmux & GPIO controller driver of
> Intel Lightning Mountain SoC.
> 
> Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
> ---
>  .../bindings/pinctrl/intel,lgm-pinctrl.yaml        | 114 +++++++++++++++++++++
>  1 file changed, 114 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/intel,lgm-pinctrl.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/intel,lgm-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/intel,lgm-pinctrl.yaml
> new file mode 100644
> index 000000000000..961ac877a962
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/intel,lgm-pinctrl.yaml
> @@ -0,0 +1,114 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bindings/pinctrl/intel,lgm-pinctrl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Intel Lightning Mountain SoC pinmux & GPIO controller binding
> +
> +maintainers:
> +  - Rahul Tanwar <rahul.tanwar@linux.intel.com>
> +
> +description: |
> +  Pinmux & GPIO controller controls pin multiplexing & configuration including
> +  GPIO function selection & GPIO attributes configuration.
> +
> +  Please refer to [1] for details of the common pinctrl bindings used by the
> +  client devices.
> +
> +  [1] Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> +
> +properties:
> +  compatible:
> +    const: intel,lgm-pinctrl
> +
> +  reg:
> +    maxItems: 1
> +
> +# Client device subnode's properties
> +patternProperties:
> +  "^.*@[0-9a-fA-F]+$":

A unit address is wrong here. Please define some pattern we can match 
on. '-pins$' perhaps.

> +    type: object
> +    description:
> +      Pinctrl node's client devices use subnodes for desired pin configuration.
> +      Client device subnodes use below standard properties.
> +
> +    properties:
> +      function:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        description:
> +          A string containing the name of the function to mux to the group.
> +
> +      groups:
> +        $ref: /schemas/types.yaml#/definitions/string-array
> +        description:
> +          An array of strings identifying the list of groups.
> +
> +      pins:
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        description:
> +          List of pins to select with this function.
> +
> +      pinmux:
> +        description: The applicable mux group.
> +        allOf:
> +          - $ref: "/schemas/types.yaml#/definitions/uint32"
> +          - enum:
> +              - 0 #PINMUX_GPIO
> +              - 1
> +              - 2
> +              - 3
> +              - 4
> +
> +      bias-pull-up:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Specifies pull-up configuration.

Isn't this boolean?

> +
> +      bias-pull-down:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Specifies pull-down configuration.

And this?

Though looks like sometimes it has a value? Pull strength I guess.

> +
> +      drive-strength:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Enables driver-current.
> +
> +      slew-rate:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Enables slew-rate.
> +
> +      drive-open-drain:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Specifies open-drain configuration.

boolean?

> +
> +      output-enable:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Specifies if the pin is to be configured as output.

boolean?

But really, all of these should have a common schema defining the types 
and only put any additional constraints here.

> +
> +
> +    required:
> +      - function
> +      - groups
> +
> +required:
> +  - compatible
> +  - reg

additionalProperties: false

> +
> +examples:
> +  # Pinmux controller node
> +  - |
> +    pinctrl: pinctrl@e2880000 {
> +          compatible = "intel,lgm-pinctrl";
> +          reg = <0xe2880000 0x100000>;
> +
> +          # Client device subnode
> +          uart0:uart0 {

space              ^

> +                pins = <64>, /* UART_RX0 */
> +                             <65>; /* UART_TX0 */
> +                function = "CONSOLE_UART0";
> +                pinmux = <1>,
> +                         <1>;
> +                groups = "CONSOLE_UART0";
> +          };
> +    };
> +
> +...
> -- 
> 2.11.0
>