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1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)2%YAML 1.23---4$id: http://devicetree.org/schemas/mailbox/mediatek,gce-props.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: MediaTek Global Command Engine Common Properties8 9maintainers:10 - Houlong Wei <houlong.wei@mediatek.com>11 12description:13 The Global Command Engine (GCE) is an instruction based, multi-threaded,14 single-core command dispatcher for MediaTek hardware. The Command Queue15 (CMDQ) mailbox driver is a driver for GCE, implemented using the Linux16 mailbox framework. It is used to receive messages from mailbox consumers17 and configure GCE to execute the specified instruction set in the message.18 We use mediatek,gce-mailbox.yaml to define the properties for CMDQ mailbox19 driver. A device driver that uses the CMDQ driver to configure its hardware20 registers is a mailbox consumer. The mailbox consumer can request a mailbox21 channel corresponding to a GCE hardware thread to send a message, specifying22 that the GCE thread to configure its hardware. The mailbox provider can also23 reserve a mailbox channel to configure GCE hardware register by the specific24 GCE thread. This binding defines the common GCE properties for both mailbox25 provider and consumers.26 27properties:28 mediatek,gce-events:29 description:30 GCE has an event table in SRAM, consisting of 1024 event IDs (0~1023).31 Each event ID has a boolean event value with the default value 0.32 The property mediatek,gce-events is used to obtain the event IDs.33 Some gce-events are hardware-bound and cannot be changed by software.34 For instance, in MT8195, when VDO0_MUTEX is stream done, VDO_MUTEX will35 send an event signal to GCE, setting the value of event ID 597 to 1.36 Similarly, in MT8188, the value of event ID 574 will be set to 1 when37 VOD0_MUTEX is stream done.38 On the other hand, some gce-events are not hardware-bound and can be39 changed by software. For example, in MT8188, we can set the value of40 event ID 855, which is not bound to any hardware, to 1 when the driver41 in the secure world completes a task. However, in MT8195, event ID 85542 is already bound to VDEC_LAT1, so we need to select another event ID to43 achieve the same purpose. This event ID can be any ID that is not bound44 to any hardware and is not yet used in any software driver.45 To determine if the event ID is bound to the hardware or used by a46 software driver, refer to the GCE header47 include/dt-bindings/gce/<chip>-gce.h of each chip.48 $ref: /schemas/types.yaml#/definitions/uint32-array49 minItems: 150 maxItems: 3251 52additionalProperties: true53