[PATCH 1/3] dt-bindings: rtc: Add sii,wakealarm-output-pin property for S35390A

[Alexandre Belloni]

On 30/06/2026 19:22:21+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 sii,wakealarm-output-pin property to enable the use of the output
> pin for interrupt signal 1 for the wake alarm, which makes it possible to
> set an wake alarm on Synology NAS devices.
> 
> Signed-off-by: Markus Probst <markus.probst at posteo.de>
> ---
>  .../devicetree/bindings/rtc/sii,s35390a.yaml       | 54 ++++++++++++++++++++++
>  .../devicetree/bindings/rtc/trivial-rtc.yaml       |  3 --
>  MAINTAINERS                                        |  1 +
>  include/dt-bindings/rtc/s35390a.h                  |  9 ++++
>  4 files changed, 64 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..31a578673870
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/sii,s35390a.yaml
> @@ -0,0 +1,54 @@
> +# 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:
> +  - Alexandre Belloni <alexandre.belloni at bootlin.com>
> +
> +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
> +
> +  sii,wakealarm-output-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [1, 2]
> +    description: |
> +      The output pin to wake up the system.
> +      Default will use the output pin for interrupt signal 2.
> +        <S35390A_OUTPUT_PIN_INT1> : Output pin for interrupt signal 1
> +        <S35390A_OUTPUT_PIN_INT2> : Output pin for interrupt signal 2
> +

Ideally, we'd get a proper pinctrl driver part for this because what
happens if you want interrupts on both pin or clock output on both pins
or any combination of interrupts and clocks?


-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com