[PATCH v3 1/5] dt-bindings: rtc: Add pinctrl for S35390A
Markus Probst
markus.probst at posteo.de
Wed Aug 12 05:27:44 PDT 2026
On Tue, 2026-08-11 at 21:08 -0500, Rob Herring wrote:
> On Wed, Aug 05, 2026 at 07:32:27PM +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 | 109 +++++++++++++++++++++
> > .../devicetree/bindings/rtc/trivial-rtc.yaml | 3 -
> > MAINTAINERS | 1 +
> > 3 files changed, 110 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..0355f17f233a
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/rtc/sii,s35390a.yaml
> > @@ -0,0 +1,109 @@
> > +# 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>
>
> This should be someone with the h/w, not subsystem maintainer.
There has been a discussion about this before.
See
https://lore.kernel.org/all/20260701-bronze-jaguar-of-perfection-028bac@quoll/
and replies.
If desired I can use my own name.
>
> > +
> > +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:
> > + - $ref: rtc.yaml#
> > +
> > +properties:
> > + compatible:
> > + const: sii,s35390a
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + interrupts:
> > + minItems: 1
> > + maxItems: 2
> > + description: Supports up to 2 interrupt lines via the INT1 and INT2 pins.
> > +
> > + wakeup-parent: true
> > +
> > + wakeup-source: true
> > +
> > + "#clock-cells":
> > + const: 1
> > +
> > +patternProperties:
> > + "^pins":
>
> Do you need wild cards here? Wouldn't just 'pins' for the node name be
> fine?
Pin control by itself supports multiple states.
I am not sure if this has a usecase with this device though.
>
> > + type: object
> > + patternProperties:
> > + "-pins$":
> > + type: object
> > + properties:
> > + pins:
> > + $ref: /schemas/pinctrl/pinmux-node.yaml#/properties/pins
> > + items:
> > + enum:
> > + - int1
> > + - int2
> > +
> > + function:
> > + $ref: /schemas/types.yaml#/definitions/string
> > + 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:
> > + - function
> > +
> > + additionalProperties: false
> > +
> > + additionalProperties: false
> > +
> > +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>;
> > +
> > + rtc_pins_default: pins {
> > + int1-pins {
> > + pins = "int1";
> > + function = "wakeup";
> > + };
> > + int2-pins {
> > + pins = "int2";
> > + function = "disable";
> > + };
> > + };
> > + };
> > + };
> > diff --git a/Documentation/devicetree/bindings/rtc/trivial-rtc.yaml b/Documentation/devicetree/bindings/rtc/trivial-rtc.yaml
> > index f4d0eed98a08..7b3f682ef4d5 100644
> > --- a/Documentation/devicetree/bindings/rtc/trivial-rtc.yaml
> > +++ b/Documentation/devicetree/bindings/rtc/trivial-rtc.yaml
> > @@ -81,8 +81,6 @@ properties:
> > - ricoh,rv5c386
> > # I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
> > - ricoh,rv5c387a
> > - # 2-wire CMOS real-time clock
> > - - sii,s35390a
> > # ST SPEAr Real-time Clock
> > - st,spear600-rtc
> > # VIA/Wondermedia VT8500 Real-time Clock
> > @@ -105,5 +103,4 @@ required:
> > - reg
> >
> > additionalProperties: false
> > -
> > ...
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 5114e6db7307..4c8bc35cfe55 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -22695,6 +22695,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git
> > F: Documentation/admin-guide/rtc.rst
> > F: Documentation/devicetree/bindings/rtc/
> > F: drivers/rtc/
> > +F: include/dt-bindings/rtc/
> > F: include/linux/rtc.h
> > F: include/linux/rtc/
> > F: include/uapi/linux/rtc.h
> >
> > --
> > 2.54.0
> >
Thanks
- Markus Probst
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