Re: [PATCH RFC 04/10] dt-bindings: mailbox: Add MT8196 GPUEB Mailbox

Rob Herring
2025-09-05T23:31:04Z

On Fri, Sep 05, 2025 at 12:23:00PM +0200, Nicolas Frattaroli wrote:
> The MediaTek MT8196 SoC includes an embedded MCU referred to as "GPUEB",
> acting as glue logic to control power and frequency of the Mali GPU.
> This MCU runs proprietary firmware for this purpose, and the main
> application processor communicates with it through a mailbox.
>
> Add a binding that describes this mailbox.
>
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> ---
> .../mailbox/mediatek,mt8196-gpueb-mbox.yaml | 64 ++++++++++++++++++++++
> 1 file changed, 64 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mailbox/mediatek,mt8196-gpueb-mbox.yaml b/Documentation/devicetree/bindings/mailbox/mediatek,mt8196-gpueb-mbox.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..506723d54ae0a429b462914f3666184c24c4fc5a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/mediatek,mt8196-gpueb-mbox.yaml
> @@ -0,0 +1,64 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/mediatek,mt8196-gpueb-mbox.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek MFlexGraphics GPUEB Mailbox Controller
> +
> +maintainers:
> + - Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> +
> +properties:
> + compatible:
> + enum:
> + - mediatek,mt8196-gpueb-mbox
> +
> + reg:
> + items:
> + - description: mailbox data registers
> + - description: mailbox control registers
> +
> + reg-names:
> + items:
> + - const: mbox
> + - const: mbox_ctl

'mbox' is redundant. So 'data' and 'ctl'?

> +
> + clocks:
> + items:
> + - description: main clock of the GPUEB MCU
> +
> + interrupts:
> + items:
> + - description: fires when a new message is received
> +
> + "#mbox-cells":
> + const: 1
> + description:
> + The number of the mailbox channel.
> +
> +required:
> + - compatible
> + - reg
> + - reg-names
> + - clocks
> + - interrupts
> + - "#mbox-cells"
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/mediatek,mt8196-clock.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + gpueb_mbox: mailbox@4b09fd80 {

Drop unused labels.

> + compatible = "mediatek,mt8196-gpueb-mbox";
> + reg = <0x4b09fd80 0x280>,
> + <0x4b170000 0x7c>;
> + reg-names = "mbox", "mbox_ctl";
> + clocks = <&topckgen CLK_TOP_MFG_EB>;
> + interrupts = <GIC_SPI 608 IRQ_TYPE_LEVEL_HIGH 0>;
> + #mbox-cells = <1>;
> + };
>
> --
> 2.51.0
>