Re: [PATCH 4/9] dt-bindings: pinctrl: Add UltraRISC DP1000 pinctrl bindings

[Conor Dooley <conor.dooley@microchip.com>]

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On Fri, May 15, 2026 at 09:18:00AM +0800, Jia Wang wrote:
> Add bindings for the pin controllers on the UltraRISC DP1000 RISC-V SoC.
> 
> Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
> ---
>  .../bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml | 168 +++++++++++++++++++++
>  MAINTAINERS                                        |   7 +
>  .../dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h |  65 ++++++++
>  3 files changed, 240 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml
> new file mode 100644
> index 000000000000..c7ed1f96382a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml
> @@ -0,0 +1,168 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pinctrl/ultrarisc,dp1000-pinctrl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: UltraRISC DP1000 Pin Controller
> +maintainers:
> +  - Jia Wang <wangjia@ultrarisc.com>
> +
> +description: |
> +  UltraRISC RISC-V SoC DP1000 pin controller.
> +
> +  The binding supports two child node styles under the same controller
> +  compatible:
> +
> +  - legacy DP1000-specific nodes using phandle-array properties
> +    `pinctrl-pins` and `pinconf-pins`
> +  - generic pinctrl nodes using `pins`, `function` and generic pin
> +    configuration properties
> +
> +properties:
> +  compatible:
> +    const: ultrarisc,dp1000-pinctrl
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#pinctrl-cells":
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +patternProperties:
> +  '.*-pins$':
> +    type: object
> +    allOf:
> +      - $ref: /schemas/pinctrl/pincfg-node.yaml#
> +      - $ref: /schemas/pinctrl/pinmux-node.yaml#
> +    additionalProperties: false
> +    properties:
> +      pinctrl-pins:
> +        description: |
> +          The list of pins and their mux settings that properties in the node
> +          apply to. The format: `PORT  PIN  FUNCTION`.
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        minItems: 1
> +        maxItems: 32
> +      pinconf-pins:
> +        description: |
> +          The list of pins and their pad configuration that properties in the
> +          node apply to. The format: `PORT  PIN  CONF`.
> +          CONF is a DP1000-specific encoding of pull and drive strength as
> +          defined in dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h.
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        minItems: 1
> +        maxItems: 32

These two "legacy" properties are not acceptable, sorry.

> +      pins:
> +        description: List of pins affected by this state node.
> +        minItems: 1
> +        uniqueItems: true
> +        items:
> +          type: string
> +          pattern: '^(PA([0-9]|1[0-5])|P[BCD][0-7]|LPC([0-9]|1[0-2]))$'

The regex might be neat, but I don't think that it is very
user-friendly. It's hard to read this and understand what the pin
namings actually are. Could you break this down into multiple patterns,
one for each type of pin?
I think that would make reading it much simpler.

> +
> +      function:
> +        description: |
> +          Mux function to select for the listed pins.
> +          gpio maps to the hardware default mode. The default mode is
> +          GPIO for PA/PB/PC/PD pins and LPC for LPC pins.
> +          func1 is not supported on LPC pins.
> +        enum:
> +          - gpio

> +          - func0
> +          - func1

These two do no seem to be very useful to people writing devicetrees.
What do func0 and func1 represent? I assume that they represent
something different for different pins? For example, maybe qspi for LPC
or i2c for PC?

pw-bot: changes-requested

Cheers,
Conor.

> +
> +      bias-disable: true
> +      bias-high-impedance: true
> +      bias-pull-up: true
> +      bias-pull-down: true
> +
> +      drive-strength:
> +        description: Output drive strength in mA.
> +        enum: [20, 27, 33, 40]
> +
> +    oneOf:
> +      - allOf:
> +          - anyOf:
> +              - required: [pinctrl-pins]
> +              - required: [pinconf-pins]
> +          - not:
> +              required: [pins]
> +      - allOf:
> +          - required: [pins]
> +          - not:
> +              anyOf:
> +                - required: [pinctrl-pins]
> +                - required: [pinconf-pins]
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      pinmux@11081000 {
> +        compatible = "ultrarisc,dp1000-pinctrl";
> +        reg = <0x0 0x11081000  0x0 0x1000>;
> +        #pinctrl-cells = <2>;
> +
> +        i2c0-pins {
> +          pins = "PA12", "PA13";
> +          function = "func0";
> +          bias-pull-up;
> +          drive-strength = <33>;
> +        };
> +
> +        uart0-pins {
> +          pins = "PA8", "PA9";
> +          function = "func1";
> +          bias-pull-up;
> +          drive-strength = <33>;
> +        };
> +      };
> +    };
> +
> +  - |
> +    /* Legacy example */
> +    #include <dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h>
> +
> +    soc {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      pinmux@11081000 {
> +        compatible = "ultrarisc,dp1000-pinctrl";
> +        reg = <0x0 0x11081000  0x0 0x1000>;
> +        #pinctrl-cells = <2>;
> +
> +        i2c0-pins {
> +          pinctrl-pins = <
> +            UR_DP1000_IOMUX_A  12  UR_DP1000_FUNC0
> +            UR_DP1000_IOMUX_A  13  UR_DP1000_FUNC0
> +          >;
> +
> +          pinconf-pins = <
> +            UR_DP1000_IOMUX_A  12  UR_DP1000_BIAS(UR_DP1000_PULL_UP,
> +                                                  UR_DP1000_DRIVE_DEF)
> +            UR_DP1000_IOMUX_A  13  UR_DP1000_BIAS(UR_DP1000_PULL_UP,
> +                                                  UR_DP1000_DRIVE_DEF)
> +          >;
> +        };
> +
> +        uart0-pins {
> +          pinctrl-pins = <
> +            UR_DP1000_IOMUX_A  8  UR_DP1000_FUNC1
> +            UR_DP1000_IOMUX_A  9  UR_DP1000_FUNC1
> +          >;
> +
> +          pinconf-pins = <
> +            UR_DP1000_IOMUX_A  8   UR_DP1000_BIAS(UR_DP1000_PULL_UP,
> +                                                  UR_DP1000_DRIVE_DEF)
> +            UR_DP1000_IOMUX_A  9   UR_DP1000_BIAS(UR_DP1000_PULL_UP,
> +                                                  UR_DP1000_DRIVE_DEF)
> +          >;
> +        };
> +      };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5bf971ff48b2..baaaa46b1a56 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -27358,6 +27358,13 @@ S:	Maintained
>  F:	drivers/usb/common/ulpi.c
>  F:	include/linux/ulpi/
>  
> +ULTRARISC DP1000 PINCTRL DRIVER
> +M:	Jia Wang <wangjia@ultrarisc.com>
> +L:	linux-gpio@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/pinctrl/ultrarisc,dp1000-pinctrl.yaml
> +F:	include/dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h
> +
>  ULTRATRONIK BOARD SUPPORT
>  M:	Goran Rađenović <goran.radni@gmail.com>
>  M:	Börge Strümpfel <boerge.struempfel@gmail.com>
> diff --git a/include/dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h b/include/dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h
> new file mode 100644
> index 000000000000..bef28115898d
> --- /dev/null
> +++ b/include/dt-bindings/pinctrl/ultrarisc,dp1000-pinctrl.h
> @@ -0,0 +1,65 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +/*
> + * UltraRISC DP1000 pinctrl header.
> + *
> + * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
> + */
> +
> +#ifndef _DT_BINDINGS_PINCTRL_ULTRARISC_DP1000_PINCTRL_H
> +#define _DT_BINDINGS_PINCTRL_ULTRARISC_DP1000_PINCTRL_H
> +
> +/**
> + * UltraRISC DP1000 IO pad configuration
> + * port: A, B, C, D, LPC
> + *     Pin in the port
> + * pin:
> + *     PA: 0 - 15
> + *     PB-PD: 0 - 7
> + *     LPC: 0 - 12
> + * func:
> + *     UR_DP1000_FUNC_DEF: default
> + *     UR_DP1000_FUNC0: func0
> + *     UR_DP1000_FUNC1: func1
> + */
> +#define UR_DP1000_IOMUX_A		0x0
> +#define UR_DP1000_IOMUX_B		0x1
> +#define UR_DP1000_IOMUX_C		0x2
> +#define UR_DP1000_IOMUX_D		0x3
> +#define UR_DP1000_IOMUX_LPC		0x4
> +
> +#define UR_DP1000_FUNC_DEF		0
> +#define UR_DP1000_FUNC0			1
> +#define UR_DP1000_FUNC1			0x10000
> +
> +/**
> + * Configure pull up/down resistor of the IO pin
> + * UR_DP1000_PULL_DIS: disable pull-up and pull-down
> + * UR_DP1000_PULL_UP: enable pull-up
> + * UR_DP1000_PULL_DOWN: enable pull-down
> + */
> +#define UR_DP1000_PULL_DIS	0
> +#define UR_DP1000_PULL_UP	1
> +#define UR_DP1000_PULL_DOWN	2
> +/**
> + * Configure drive strength of the IO pin
> + * UR_DP1000_DRIVE_DEF: default value, reset value is 2
> + * UR_DP1000_DRIVE_0: 20mA
> + * UR_DP1000_DRIVE_1: 27mA
> + * UR_DP1000_DRIVE_2: 33mA
> + * UR_DP1000_DRIVE_3: 40mA
> + */
> +#define UR_DP1000_DRIVE_DEF	2
> +#define UR_DP1000_DRIVE_0	0
> +#define UR_DP1000_DRIVE_1	1
> +#define UR_DP1000_DRIVE_2	2
> +#define UR_DP1000_DRIVE_3	3
> +
> +/**
> + * Combine the pull-up/down resistor and drive strength
> + * pull: UR_DP1000_PULL_DIS, UR_DP1000_PULL_UP, UR_DP1000_PULL_DOWN
> + * drive: UR_DP1000_DRIVE_DEF, UR_DP1000_DRIVE_0, UR_DP1000_DRIVE_1,
> + *        UR_DP1000_DRIVE_2, UR_DP1000_DRIVE_3
> + */
> +#define UR_DP1000_BIAS(pull, drive)		(((pull) << 2) | (drive))
> +
> +#endif /* _DT_BINDINGS_PINCTRL_ULTRARISC_DP1000_PINCTRL_H */
> 
> -- 
> 2.34.1
> 

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