Re: [RFC PATCH v3 4/5] dt-bindings: input: hid-over-spi: add the Surface Laptop 7 touchpad

From: Conor Dooley

Date: Fri Nov 06 2026 - 12:49:18 EST


On Thu, Nov 05, 2026 at 07:23:05PM +0000, Jizhou Tong wrote:
> The Surface Laptop 7 13.8-inch (Romulus13) touchpad uses HID-over-SPI
> with quad address/data transfers. Add its compatible to the common
> binding, with both bus widths fixed to four and a 20 MHz clock limit.
> The existing supply and active-low reset properties cover this device.
>
> Keep the G6 digitizer constraints unchanged. Pinctrl properties are
> already permitted by the common schemas and need no local definitions.
>
> Signed-off-by: Jizhou Tong <fqwqf@xxxxxxxxx>
> ---
> .../bindings/input/hid-over-spi.yaml | 40 +++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.yaml b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
> index bed0746f00..ec8c72493d 100644
> --- a/Documentation/devicetree/bindings/input/hid-over-spi.yaml
> +++ b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
> @@ -22,11 +22,30 @@ description: |+
> allOf:
> - $ref: /schemas/input/touchscreen/touchscreen.yaml#
> - $ref: /schemas/spi/spi-peripheral-props.yaml#
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: microsoft,romulus13-touchpad
> + then:
> + properties:
> + spi-max-frequency:
> + maximum: 20000000
> + spi-rx-bus-width:
> + items:
> + - const: 4

Should this not just be "const: 4", since the property is not an array?

Cheers,
Conor.

> + spi-tx-bus-width:
> + items:
> + - const: 4
> + required:
> + - spi-rx-bus-width
> + - spi-tx-bus-width
>
> properties:
> compatible:
> enum:
> - microsoft,g6-touch-digitizer
> + - microsoft,romulus13-touchpad
>
> reg:
> maxItems: 1
> @@ -73,3 +92,24 @@ examples:
> pinctrl-0 = <&ts_d6_int_bias>;
> };
> };
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + #include <dt-bindings/gpio/gpio.h>
> +
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + touchpad@0 {
> + compatible = "microsoft,romulus13-touchpad";
> + reg = <0>;
> + spi-max-frequency = <20000000>;
> + spi-rx-bus-width = <4>;
> + spi-tx-bus-width = <4>;
> + interrupts-extended = <&tlmm 3 IRQ_TYPE_LEVEL_LOW>;
> + vdd-supply = <&vreg_ts_5p0>;
> + reset-gpios = <&tlmm 120 GPIO_ACTIVE_LOW>;
> + pinctrl-0 = <&touchpad_reset>;
> + pinctrl-names = "default";
> + };
> + };

Attachment: signature.asc
Description: PGP signature