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

Nicolas Frattaroli
2025-09-05T10:24:28Z

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
+
+ 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 {
+ 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