Re: [PATCH 2/2] dt-bindings: pinctrl: mcp23s08: Add multi-chip example

[Krzysztof Kozlowski <krzk@kernel.org>]

On Tue, Jan 13, 2026 at 03:29:48PM +0100, Jean-Michel Hautbois wrote:
> Enable gpio-line-names property in the schema and add example showing
> how to use it with multiple MCP23S08/17/18 chips sharing the same SPI
> chip select. Names are assigned sequentially in hardware address order.
> 
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
> ---
>  .../bindings/pinctrl/microchip,mcp23s08.yaml       | 33 ++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,mcp23s08.yaml b/Documentation/devicetree/bindings/pinctrl/microchip,mcp23s08.yaml
> index e07f4723de17..667be31b6da3 100644
> --- a/Documentation/devicetree/bindings/pinctrl/microchip,mcp23s08.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/microchip,mcp23s08.yaml
> @@ -42,6 +42,8 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  gpio-line-names: true

Variable number of GPIOs? No constraints possible at all? 

> +
>    reset-gpios:
>      description: GPIO specifier for active-low reset pin.
>      maxItems: 1
> @@ -159,3 +161,34 @@ examples:
>              microchip,spi-present-mask = /bits/ 8 <0x01>;
>          };
>      };
> +
> +  - |
> +    /* Multiple chips sharing same SPI CS with gpio-line-names */
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        gpio@0 {
> +            compatible = "microchip,mcp23s17";
> +            reg = <0>;
> +            gpio-controller;
> +            #gpio-cells = <2>;
> +            spi-max-frequency = <10000000>;
> +            /* Two chips at hardware addresses 0 and 1 */
> +            microchip,spi-present-mask = /bits/ 8 <0x03>;
> +            /*
> +             * Names assigned sequentially in address order.
> +             * First 16 names for chip at address 0 (GPA0-7, GPB0-7).
> +             * Next 16 names for chip at address 1 (GPA0-7, GPB0-7).
> +             */
> +            gpio-line-names =

Just extend existing example. There is little point in adding one new
example per one new different property.

Best regards,
Krzysztof