Re: [PATCH v3 1/3] dt-bindings: mailbox: Add mediatek,gce-props.yaml

Conor Dooley
2024-01-19T16:44:10Z

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Rob,

On Fri, Jan 19, 2024 at 02:32:22PM +0800, Jason-JH.Lin wrote:
> Add mediatek,gce-props.yaml for common GCE properties that is used for
> both mailbox providers and consumers. We place the common property
> "mediatek,gce-events" in this binding currently.
>
> The property "mediatek,gce-events" is used for GCE event ID corresponding
> to a hardware event signal sent by the hardware or a sofware driver.
> If the mailbox providers or consumers want to manipulate the value of
> the event ID, they need to know the specific event ID.
>
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
> .../bindings/mailbox/mediatek,gce-props.yaml | 52 +++++++++++++++++++

Is bindings/mailbox the correct directory to put this in?

> 1 file changed, 52 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/mediatek,gce-props.yaml
>
> diff --git a/Documentation/devicetree/bindings/mailbox/mediatek,gce-props.yaml b/Documentation/devicetree/bindings/mailbox/mediatek,gce-props.yaml
> new file mode 100644
> index 000000000000..68b519ff089f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/mediatek,gce-props.yaml
> @@ -0,0 +1,52 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mailbox/mediatek,gce-props.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek Global Command Engine Common Propertes
> +
> +maintainers:
> + - Houlong Wei <houlong.wei@mediatek.com>
> +
> +description:
> + The Global Command Engine (GCE) is an instruction based, multi-threaded,
> + single-core command dispatcher for MediaTek hardware. The Command Queue
> + (CMDQ) mailbox driver is a driver for GCE, implemented using the Linux
> + mailbox framework. It is used to receive messages from mailbox consumers
> + and configure GCE to execute the specified instruction set in the message.
> + We use mediatek,gce-mailbox.yaml to define the properties for CMDQ mailbox
> + driver. A device driver that uses the CMDQ driver to configure its hardware
> + registers is a mailbox consumer. The mailbox consumer can request a mailbox
> + channel corresponding to a GCE hardware thread to send a message, specifying
> + that the GCE thread to configure its hardware. The mailbox provider can also
> + reserved a mailbox channel to configure GCE hardware register by the spcific
> + GCE thread. This binding defines the common GCE properties for both mailbox
> + provider and consumers.
> +
> +properties:
> + mediatek,gce-events:
> + description:
> + GCE has an event table in SRAM, consisting of 1024 event IDs (0~1023).
> + Each event ID has a boolean event value with the default value 0.
> + The property mediatek,gce-events is used to obtain the event IDs.
> + Some gce-events are hardware-bound and cannot be changed by software.
> + For instance, in MT8195, when VDO0_MUTEX is stream done, VDO_MUTEX will
> + send an event signal to GCE, setting the value of event ID 597 to 1.
> + Similarly, in MT8188, the value of event ID 574 will be set to 1 when
> + VOD0_MUTEX is stream done.
> + On the other hand, some gce-events are not hardware-bound and can be
> + changed by software. For example, in MT8188, we can set the value of
> + event ID 855, which is not bound to any hardware, to 1 when the driver
> + in the secure world completes a task. However, in MT8195, event ID 855
> + is already bound to VDEC_LAT1, so we need to select another event ID to
> + achieve the same purpose. This event ID can be any ID that is not bound
> + to any hardware and is not yet used in any software driver.
> + To determine if the event ID is bound to the hardware or used by a
> + software driver, refer to the GCE header
> + include/dt-bindings/gce/<chip>-gce.h of each chip.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + minItems: 1
> + maxItems: 1024
> +
> +additionalProperties: true
> --
> 2.18.0
>

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