Re: [PATCH 3/6] dt-bindings: mailbox: Add AMD PL Mailbox IP

[Krzysztof Kozlowski <krzk@kernel.org>]

On Wed, Oct 14, 2026 at 02:34:23PM -0700, Ben Levinsky wrote:
> Document the AMD programmable-logic Mailbox IP used for bidirectional
> FIFO communication between two processor-facing interfaces.
> 
> The same IP is used on ZynqMP, Versal, Versal NET and Versal Gen 2.
> Name each SoC in its compatible, and use amd,zynqmp-pl-mbox-2.1 as the
> fallback that drivers match.
> 
> Define the transmit and receive channel indices together with the register
> aperture, interrupt, and interface clock. Describe the FIFO depth chosen
> when the IP is configured, so that the driver can size received messages
> to it.
> 
> Assisted-by: LLM sparse

How sparse assists here? It's something new. Since when does it parse
yaml code?

> Signed-off-by: Ben Levinsky <ben.levinsky@amd.com>
> ---
>  .../mailbox/amd,zynqmp-pl-mbox-2.1.yaml       | 74 +++++++++++++++++++
>  1 file changed, 74 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/amd,zynqmp-pl-mbox-2.1.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/amd,zynqmp-pl-mbox-2.1.yaml b/Documentation/devicetree/bindings/mailbox/amd,zynqmp-pl-mbox-2.1.yaml
> new file mode 100644
> index 000000000000..2cc0d106b888
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/amd,zynqmp-pl-mbox-2.1.yaml
> @@ -0,0 +1,74 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/amd,zynqmp-pl-mbox-2.1.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AMD Programmable Logic Mailbox IP
> +
> +maintainers:
> +  - Ben Levinsky <ben.levinsky@amd.com>
> +
> +description: |
> +  The AMD Programmable Logic Mailbox IP provides bidirectional message passing
> +  between two processor-facing interfaces. Each interface writes messages to
> +  a send FIFO and reads messages from a receive FIFO. The register aperture,
> +  interrupt, and clock described by a node belong to one processor-facing
> +  interface. Channel 0 represents transmit and channel 1 represents receive
> +  for that interface.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: amd,zynqmp-pl-mbox-2.1

What is 2.1? Your SoC has different versions?

> +      - items:
> +          - enum:
> +              - amd,versal-pl-mbox-2.1
> +              - amd,versal-net-pl-mbox-2.1
> +              - amd,versal2-pl-mbox-2.1
> +          - const: amd,zynqmp-pl-mbox-2.1
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  amd,mbox-pl-fifo-len:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 16
> +    maximum: 8192
> +    default: 16
> +    description:
> +      Depth of the send and receive FIFOs in 32-bit words, as configured by
> +      the C_MAILBOX_DEPTH parameter of the IP. Must match the configured
> +      depth.

So you have multiple mailboxes per one soc different in this?

Best regards,
Krzysztof