[PATCH 1/3] dt-bindings: mailbox: mediatek: Add apu-mailbox document

[Krzysztof Kozlowski]

On 24/10/2024 11:25, Karl.Li wrote:
> From: Karl Li <karl.li at mediatek.com>
> 
> Add apu-mailbox dt-binding document.

We see from the diff. What we see is what is APU and this hardware?

A nit, subject: drop second/last, redundant "document". The
"dt-bindings" prefix is already stating that these are bindings so a
document.
See also:
https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

> 
> Signed-off-by: Karl Li <karl.li at mediatek.com>
> ---
>  .../mailbox/mediatek,apu-mailbox.yaml         | 55 +++++++++++++++++++
>  1 file changed, 55 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/mediatek,apu-mailbox.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/mediatek,apu-mailbox.yaml b/Documentation/devicetree/bindings/mailbox/mediatek,apu-mailbox.yaml
> new file mode 100644
> index 000000000000..cb4530799bef
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/mediatek,apu-mailbox.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/mediatek,apu-mailbox.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek APU mailbox

What is APU?

> +
> +maintainers:
> +  - Karl Li <Karl.Li at mediatek.com>
> +
> +description:
> +  The MediaTek APU-Mailbox facilitates communication with the
> +  APU microcontroller. Within the MediaTek APU subsystem, a
> +  message passing mechanism is built on top of the mailbox system.
> +  The mailbox only has limited space for each message. The firmware
> +  expects the message header from the mailbox, while the message body
> +  is passed through some fixed shared memory.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - mediatek,mt8188-apu-mailbox
> +      - mediatek,mt8196-apu-mailbox
> +
> +  "#mbox-cells":
> +    const: 1
> +    description:
> +      The cell describe which channel the device will use.
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - "#mbox-cells"
> +  - reg
> +  - interrupts
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    apu_mailbox: mailbox at 4c200000 {

Drop unused label.

> +      compatible = "mediatek,mt8196-apu-mailbox";
> +      reg = <0 0x4c200000 0 0xfffff>;
> +      interrupts = <GIC_SPI 638 IRQ_TYPE_LEVEL_HIGH 0>;

4 cells? No warnings on this?

> +      #mbox-cells = <1>;
> +    };

Best regards,
Krzysztof