Re: [PATCH 1/3] dt-bindings: rtc: Add Raspberry Pi 5 RTC binding

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 09/09/2026 16:12:58+0200, Sander Speetjens wrote:
> Add device tree bindings for the Raspberry Pi 5 RTC.
> Located in a custom DA9091 PMIC and accesed trough the firmware mailbox.
> 
> Signed-off-by: Sander Speetjens <sander.speetjens@gmail.com>
> Assisted-by: Grok
> ---
>  .../bindings/rtc/raspberrypi,rtc-rpi.yaml     | 48 +++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rtc/raspberrypi,rtc-rpi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rtc/raspberrypi,rtc-rpi.yaml b/Documentation/devicetree/bindings/rtc/raspberrypi,rtc-rpi.yaml
> new file mode 100644
> index 000000000000..e9bade7f8c91
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/raspberrypi,rtc-rpi.yaml
> @@ -0,0 +1,48 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/raspberrypi,rtc-rpi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Raspberry Pi firmware RTC
> +
> +maintainers:
> +  - Jonathan Bell <jonathan@raspberrypi.com>
> +
> +description: |
> +  Raspberry Pi RTC from the DA9091 accessed through the Raspberry Pi firmware
> +  property interface.
> +
> +properties:
> +  compatible:
> +    const: raspberrypi,rpi-rtc
> +
> +  firmware:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      Phandle to the Raspberry Pi firmware device.
> +
> +  trickle-charge-microvolt:

This should probably be trickle-voltage-millivolt

> +    description:
> +      RTC backup battery trickle-charge voltage. A value of 0 disables
> +      trickle charging.
> +    anyOf:
> +      - const: 0
> +      - minimum: 1300000
> +        maximum: 4400000
> +
> +required:
> +  - compatible
> +  - firmware
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    rtc {
> +        compatible = "raspberrypi,rpi-rtc";
> +        firmware = <&firmware>;
> +        status = "okay";
> +        trickle-charge-microvolt = <0>;
> +    };
> -- 
> 2.55.0
> 

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