On Sun, Sep 06, 2026 at 02:41:12AM +0200, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <[email protected]>
>
> The modem firmware on Google Pixel 3 - 5a devices expects the application
> processor to publish SoC platform information in a vendor-defined SMEM
> item before the modem boots.
>
> Assisted-by: LLM
> Signed-off-by: David Heidelberg <[email protected]>
> ---
> .../bindings/soc/google/google,modemsmem.yaml | 39
> ++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git
> a/Documentation/devicetree/bindings/soc/google/google,modemsmem.yaml
> b/Documentation/devicetree/bindings/soc/google/google,modemsmem.yaml
> new file mode 100644
> index 0000000000000..a5214a8093ba0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/google/google,modemsmem.yaml
> @@ -0,0 +1,39 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/google/google,modemsmem.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Google Modem Shared Memory
> +
> +maintainers:
> + - Richard Acayan <[email protected]>
> +
> +description:
> + The modem firmware on Google Pixel devices (Pixel 3 through Pixel 5a)
> + expects the application processor to publish SoC information (platform
> + type and revision) in a vendor-defined Qualcomm Shared Memory (SMEM)
> + item before the modem boots.
> +
> +properties:
> + compatible:
> + const: google,modemsmem
To me it is seems node represents the attribute of the modem remoteproc
requiring this information to be populated before its started, rather
than a thing of its own.
How about representing this as a property of the modem remoteproc node
instead (perhaps "google,require-socinfo"?) and then put the conditional
snippet in the remoteproc driver?
I'm not particularly fond of the additional codepath in the remoteproc
drivers, but I think the DeviceTree representation would be more
appropriate - and the driver changes are reasonably isolated.
> +
> + qcom,smem-id:
Let's just hard code this in the implementation until there's a need for
this to change.
Regards,
Bjorn
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Identifier of the SMEM item the SoC information is written to. Google
> + firmware uses the first vendor-reserved item.
> +
> +required:
> + - compatible
> + - qcom,smem-id
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + modemsmem {
> + compatible = "google,modemsmem";
> + qcom,smem-id = <134>;
> + };
>
> --
> 2.55.0
>
>
