Re: [PATCH v2 2/2] spi: dt-bindings: nuvoton,npcm-fiu: Convert to DT schema

[Krzysztof Kozlowski]

On Mon, Jun 08, 2026 at 08:54:18PM +0300, Tomer Maimon wrote:
> Convert the Nuvoton NPCM FIU binding to DT schema format.

You should explain here why second 'reg' is optional. It wasn't in
original binding, so you made a change to the binding during conversion.


...

> -
> diff --git a/Documentation/devicetree/bindings/spi/nuvoton,npcm-fiu.yaml b/Documentation/devicetree/bindings/spi/nuvoton,npcm-fiu.yaml
> new file mode 100644
> index 000000000000..0f95def01910
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/nuvoton,npcm-fiu.yaml

Filename: nuvoton,npcm750-fiu.yaml

> @@ -0,0 +1,91 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/spi/nuvoton,npcm-fiu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Nuvoton NPCM Flash Interface Unit (FIU) SPI Controller
> +
> +maintainers:
> +  - Tomer Maimon <tmaimon77@xxxxxxxxx>
> +
> +allOf:
> +  - $ref: spi-controller.yaml#
> +
> +description: |
> +  NPCM FIU supports single, dual and quad communication interface.
> +
> +  The NPCM7XX supports three FIU modules:
> +    FIU0 and FIUx support two chip selects
> +    FIU3 supports four chip selects.
> +
> +  The NPCM8XX supports four FIU modules:
> +    FIU0 and FIUx support two chip selects
> +    FIU1 and FIU3 support four chip selects.
> +
> +  Alias convention:
> +    The '/aliases' node should define:
> +      For NPCM7xx:  fiu0=&fiu0; fiu1=&fiu3; fiu2=&fiux;
> +      For NPCM8xx:  fiu0=&fiu0; fiu1=&fiu3; fiu2=&fiux; fiu3=&fiu1;
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nuvoton,npcm750-fiu # Poleg NPCM7XX
> +      - nuvoton,npcm845-fiu # Arbel NPCM8XX
> +
> +  reg:
> +    minItems: 1
> +    items:
> +      - description: FIU registers
> +      - description: Memory-mapped flash contents (optional)
> +
> +  reg-names:
> +    minItems: 1
> +    items:
> +      - const: control
> +      - const: memory
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - enum:
> +          - clk_spi0
> +          - clk_spi1
> +          - clk_spi3
> +          - clk_spix

This wasn't in the original binding. Nothing explains why it was added.

> +
> +  nuvoton,spix-mode:
> +    type: boolean
> +    description: Enable SPIX mode for an expansion bus to an ASIC or CPLD.
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - clocks
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/nuvoton,npcm7xx-clock.h>
> +    spi@fb000000 {
> +        compatible = "nuvoton,npcm750-fiu";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        reg = <0xfb000000 0x1000>, <0x80000000 0x10000000>;
> +        reg-names = "control", "memory";

reg and reg-names follow compatible.


Best regards,
Krzysztof