[PATCH v8 1/6] dt-bindings: rtc: Add pinctrl for S35390A

[Krzysztof Kozlowski]

On Mon, Aug 31, 2026 at 05:42:22PM +0000, Markus Probst wrote:
> Synology NAS devices use the output pin for interrupt signal 1 to wake up
> the system.
> 
> Move devicetree bindings for sii,s35390a into its own file.
> Add necessary properties to configure the individual pins via pinctrl,
> which allows the interrupt signal 1 to be used for wakeup alarm.
> 
> Signed-off-by: Markus Probst <markus.probst at posteo.de>
> ---
>  .../devicetree/bindings/rtc/sii,s35390a.yaml       | 117 +++++++++++++++++++++
>  .../devicetree/bindings/rtc/trivial-rtc.yaml       |   3 -
>  2 files changed, 117 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/rtc/sii,s35390a.yaml b/Documentation/devicetree/bindings/rtc/sii,s35390a.yaml
> new file mode 100644
> index 000000000000..dfe632c4b2c8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/sii,s35390a.yaml
> @@ -0,0 +1,117 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/sii,s35390a.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: S-35390A 2-WIRE REAL-TIME CLOCK
> +
> +maintainers:
> +  - Markus Probst <markus.probst at posteo.de>
> +
> +description:
> +  The S-35390A is a CMOS 2-wire real-time clock IC which operates with the
> +  very low current consumption in the wide range of operation voltage.
> +
> +allOf:
> +  - $ref: rtc.yaml#
> +
> +properties:
> +  compatible:
> +    const: sii,s35390a
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    minItems: 1
> +    maxItems: 2
> +    description: Supports up to 2 interrupt lines via the INT1 and INT2 pins.
> +
> +  interrupt-names:
> +    items:
> +      - const: int1
> +      - const: int2
> +
> +  wakeup-parent: true
> +
> +  wakeup-source: true
> +
> +  "#clock-cells":
> +    const: 1
> +
> +patternProperties:
> +  "^pins":
> +    type: object
> +    additionalProperties: false
> +
> +    patternProperties:
> +      "-pins$":
> +        type: object
> +        additionalProperties: false
> +
> +        allOf:
> +          - $ref: /schemas/pinctrl/pinmux-node.yaml#
> +
> +        properties:
> +          pins:
> +            minItems: 1
> +            items:
> +              enum:
> +                - int1
> +                - int2
> +
> +          function:
> +            description: |
> +              Pin function:
> +              - ignore:  Preserve the previous state.
> +              - disable: Disable pin output.
> +              - wakeup:  Output wakes up the system.
> +              - clock:   Output clock pulse.
> +              - pmin1:   Minute periodical output with 50% duty.
> +              - pmin2:   Minute periodical output L for 7.81 ms.
> +                         Can only be used with pin int1.
> +            enum:
> +              - ignore
> +              - disable
> +              - wakeup
> +              - clock
> +              - pmin1
> +              - pmin2
> +
> +        required:
> +          - pins
> +          - function
> +
> +required:
> +  - compatible
> +  - reg
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        rtc at 30 {
> +            compatible = "sii,s35390a";
> +            reg = <0x30>;
> +            pinctrl-0 = <&rtc_pins_default>;
> +            pinctrl-names = "default";
> +
> +            wakeup-parent = <&int>;

I don't understand this need. Device does not generate interrupts - no
interrupts property - thus how can it wakeup?

As explained in commit msg, the signal at int1 goes to the SoC, right?
So where does it go? To which pin of which device? &int?

Can you show complete upstream DTS using this?


Best regards,
Krzysztof