Re: [PATCH 1/2] dt-bindings: media: add axiado,ax3000-video

Krzysztof Kozlowski <[email protected]> Thu, 30 Jul 2026 10:12:17 +0200
Newsgroups org.ozlabs.lists.openbmc,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-media
Message-ID <[email protected]>
On 30/07/2026 09:26, Tzu-Hao Wei wrote:
> Add a Device Tree binding for the Axiado AX3000 and AX3005 video
> capture path. There is no local register interface to describe: frames
> arrive asynchronously into a reserved memory region written by the
> host's display engine over PCIe, and this node only identifies that
> region.
> 
> memory-region accepts an optional second entry for a host-written
> control mailbox, letting the driver detect the mode the host is
> actually driving instead of only echoing back the configured capture
> format.
> 
> Signed-off-by: Tzu-Hao Wei <[email protected]>
> ---
>  .../bindings/media/axiado,ax3000-video.yaml        | 44 ++++++++++++++++++++++
>  MAINTAINERS                                        |  8 ++++
>  2 files changed, 52 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/media/axiado,ax3000-video.yaml b/Documentation/devicetree/bindings/media/axiado,ax3000-video.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..c6d8d1843aac9f42869ff90a550b92d0bed7c16f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/axiado,ax3000-video.yaml
> @@ -0,0 +1,44 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/axiado,ax3000-video.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Axiado AX3000 Video Controller
> +
> +maintainers:
> +  - Shubhangini G <[email protected]>
> +  - Tzu-Hao Wei <[email protected]>
> +  - Prasad Bolisetty <[email protected]>
> +
> +description:
> +  Axiado AX3000 video capture controller. Reads frames written by the
> +  display engine into a shared reserved memory region and exposes them
> +  as a V4L2 capture device.

This is really incomplete. You need at least way to power things on,
reset them, provide clocks, sensors, data paths. Or at the very minimal:
START capturing the frames after configuring the resolution.

It seems you described driver or just a piece of entire video pipeline.

> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: axiado,ax3000-video
> +      - items:
> +          - const: axiado,ax3005-video
> +          - const: axiado,ax3000-video
> +
> +  memory-region:
> +    minItems: 1
> +    items:
> +      - description: video frame buffer, shared with the display engine
> +      - description: optional control mailbox, shared with the host

Why is it optional?

Best regards,
Krzysztof