Re: [PATCH v3 1/2] dt-bindings: pinctrl: add schema for NXP S32 SoCs

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 21/12/2022 08:32, Chester Lin wrote:
> Add DT schema for the pinctrl driver of NXP S32 SoC family.
> 
> Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@oss.nxp.com>
> Signed-off-by: Chester Lin <clin@suse.com>
> ---
> 
> Changes in v3:
> - Remove the minItems from reg because there's no optional item for s32g2.
> - List supported properties of pinmux-node and pincfg-node and add more
>   descriptions.
> - Adjust the location of "required:".
> - Fix descriptions and wordings.
> - Rename the yaml file to nxp,s32g2-siul2-pinctrl.yaml.
> 
> Changes in v2:
> - Remove the "nxp,pins" property since it has been moved into the driver.
> - Add descriptions for reg entries.
> - Refine the compatible name from "nxp,s32g-..." to "nxp,s32g2-...".
> - Fix schema issues and revise the example.
> - Fix the copyright format suggested by NXP.
> 
>  .../pinctrl/nxp,s32g2-siul2-pinctrl.yaml      | 129 ++++++++++++++++++
>  1 file changed, 129 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml
> new file mode 100644
> index 000000000000..1554ce14214a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml
> @@ -0,0 +1,129 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2022 NXP
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pinctrl/nxp,s32g2-siul2-pinctrl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP S32G2 pin controller
> +
> +maintainers:
> +  - Ghennadi Procopciuc <Ghennadi.Procopciuc@oss.nxp.com>
> +  - Chester Lin <clin@suse.com>
> +
> +description: |
> +  S32G2 pinmux is implemented in SIUL2 (System Integration Unit Lite2),
> +  whose memory map is split into two regions:
> +    SIUL2_0 @ 0x4009c000
> +    SIUL2_1 @ 0x44010000
> +
> +  Every SIUL2 region has multiple register types, and here only MSCR and
> +  IMCR registers need to be revealed for kernel to configure pinmux.
> +
> +  Please note that some register indexes are reserved in S32G2, such as
> +  MSCR102-MSCR111, MSCR123-MSCR143, IMCR84-IMCR118 and IMCR398-IMCR429.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nxp,s32g2-siul2-pinctrl
> +
> +  reg:
> +    description: |
> +      A list of MSCR/IMCR register regions to be reserved.
> +      - MSCR (Multiplexed Signal Configuration Register)
> +        An MSCR register can configure the associated pin as either a GPIO pin
> +        or a function output pin depends on the selected signal source.
> +      - IMCR (Input Multiplexed Signal Configuration Register)
> +        An IMCR register can configure the associated pin as function input
> +        pin depends on the selected signal source.
> +    items:
> +      - description: MSCR registers group 0 in SIUL2_0
> +      - description: MSCR registers group 1 in SIUL2_1
> +      - description: MSCR registers group 2 in SIUL2_1
> +      - description: IMCR registers group 0 in SIUL2_0
> +      - description: IMCR registers group 1 in SIUL2_1
> +      - description: IMCR registers group 2 in SIUL2_1
> +
> +patternProperties:
> +  '-pins$':
> +    type: object
> +    additionalProperties: false
> +
> +    patternProperties:
> +      '-grp[0-9]$':
> +        type: object
> +        allOf:
> +          - $ref: pinmux-node.yaml#
> +          - $ref: pincfg-node.yaml#
> +        description: |
> +          Pinctrl node's client devices specify pin muxes using subnodes,
> +          which in turn use the standard properties below.
> +
> +        properties:
> +          bias-disable: true
> +          bias-high-impedance: true
> +          bias-pull-up: true
> +          bias-pull-down: true
> +          drive-open-drain: true
> +          input-enable: true
> +          output-enable: true
> +
> +          pinmux:
> +            description: |
> +               An integer array for representing pinmux configurations of
> +               a device. Each integer consists of a PIN_ID and a 4-bit
> +               selected signal source(SSS) as IOMUX setting, which is
> +               calculated as: pinmux = (PIN_ID << 4 | SSS)
> +
> +          slew-rate:
> +            description: |
> +              0: 208MHz
> +              1-3: Reserved
> +              4: 166MHz
> +              5: 150MHz
> +              6: 133MHz
> +              7: 83MHz
> +            enum: [0, 4, 5, 6, 7]

You have known values, then use them. This is much more readable in DTS.


Best regards,
Krzysztof