Commit d1368f62 authored by Jason-JH.Lin's avatar Jason-JH.Lin Committed by Jassi Brar
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dt-bindings: mailbox: Add mediatek,gce-props.yaml 



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 software 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: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarJassi Brar <jassisinghbrar@gmail.com>
parent 256abd8e

Documentation/devicetree/bindings/mailbox/mediatek,gce-props.yaml

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# 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 Properties



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

  reserve a mailbox channel to configure GCE hardware register by the specific

  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: 32



additionalProperties: true