> > > *From: *Krzysztof Kozlowski <[email protected]> > *Date: *Thursday, October 15, 2026 at 2:46 AM > *To: *Levinsky, Ben <[email protected]> > *Cc: *[email protected] <[email protected]>; > [email protected] > <[email protected]>; [email protected] > <[email protected]>; > [email protected] <[email protected]>; [email protected] <[email protected]>; > [email protected] <[email protected]>; Simek, Michal > <[email protected]>; > [email protected] <[email protected]>; > [email protected] <[email protected]>; linux-arm- > [email protected] <[email protected]>; linux- > [email protected] <[email protected]>; Shah, Tanmay > <[email protected]> > *Subject: *Re: [PATCH 3/6] dt-bindings: mailbox: Add AMD PL Mailbox IP > > 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?
Hi Krzysztof, Thank you for the review. You are right, sparse was not used for this patch. It was only run on the C patches of the series, and I applied the same trailer to the whole series by mistake. In v2 the binding patches will name only the model, and the tool list will match what was actually used on each patch. > > > Signed-off-by: Ben Levinsky <[email protected]> > > --- > > .../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 > > +--- > > +$id: http://devicetree.org/schemas/mailbox/amd,zynqmp-pl-mbox-2.1.yaml# > <http://devicetree.org/schemas/mailbox/amd,zynqmp-pl-mbox-2.1.yaml#> > > +$schema: http://devicetree.org/meta-schemas/core.yaml# <http:// > devicetree.org/meta-schemas/core.yaml#> > > + > > +title: AMD Programmable Logic Mailbox IP > > + > > +maintainers: > > + - Ben Levinsky <[email protected]> > > + > > +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? 2.1 is the version of the Mailbox IP core in the Xilinx IP catalog (Mailbox v2.1). It is not a SoC version. The IP is synthesized into the programmable logic, so the same core is used on every SoC, and the SoC names in the compatibles do not add information. In v2 I will use a single IP-versioned compatible, "xlnx,mailbox-2.1", and drop the SoC-specific ones. This is also the compatible the Xilinx device tree generator already emits for this IP. > > > + - 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? Yes. The FIFO depth is chosen per IP instance when the design is synthesized, so one design can contain several mailboxes with different depths. The depth cannot be read from the registers, so the driver needs it from the device tree to size its receive buffer and to limit transmit messages. In v2 I will rename the property to "xlnx,mailbox-depth", after the IP parameter, and state this in its description. Thanks, Ben > > Best regards, > Krzysztof >
