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

Jason-JH.Lin
2024-01-19T06:32:37Z

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 +++++++++++++++++++
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