dt-bindings: interconnect: Add MediaTek EMI Interconnect bindings

Add bindings for the MediaTek External Memory Interface Interconnect,
which providers support system bandwidth requirements through Dynamic
Voltage Frequency Scaling Resource Collector (DVFSRC) hardware.

This adds bindings for MediaTek MT8183 and MT8195 SoCs.

Note that this is modeled as a subnode of DVFSRC for multiple reasons:
 - Some SoCs have more than one interconnect on the DVFSRC (and two
   different kinds of EMI interconnect, and also a SMI interconnect);

 - Some boards will want to not enable the interconnect driver because
   some of those are not battery powered (so they just keep the knobs
   at full thrust from the bootloader and never care scaling busses);

 - Some DVFSRC interconnect features may depend on firmware.

Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Georgi Djakov <[email protected]>

Author: AngeloGioacchino Del Regno

Documentation/devicetree/bindings/interconnect/mediatek,mt8183-emi.yaml

@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interconnect/mediatek,mt8183-emi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek External Memory Interface (EMI) Interconnect
+
+maintainers:
+  - AngeloGioacchino Del Regno <[email protected]>
+
+description: |
+  EMI interconnect providers support system bandwidth requirements through
+  Dynamic Voltage Frequency Scaling Resource Collector (DVFSRC) hardware.
+  The provider is able to communicate with the DVFSRC through Secure Monitor
+  Call (SMC).
+
+             ICC provider         ICC Nodes
+                              ----          ----
+             _________       |CPU |   |--- |VPU |
+    _____   |         |-----  ----    |     ----
+   |     |->|  DRAM   |       ----    |     ----
+   |DRAM |->|scheduler|----- |GPU |   |--- |DISP|
+   |     |->|  (EMI)  |       ----    |     ----
+   |_____|->|_________|---.   -----   |     ----
+               /|\         `-|MMSYS|--|--- |VDEC|
+                |             -----   |     ----
+                |                     |     ----
+                | change DRAM freq    |--- |VENC|
+             --------                 |     ----
+    SMC --> | DVFSRC |                |     ----
+             --------                 |--- |IMG |
+                                      |     ----
+                                      |     ----
+                                      |--- |CAM |
+                                            ----
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt8183-emi
+      - mediatek,mt8195-emi
+
+  '#interconnect-cells':
+    const: 1
+
+required:
+  - compatible
+  - '#interconnect-cells'
+
+unevaluatedProperties: false

include/dt-bindings/interconnect/mediatek,mt8183.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2021 MediaTek Inc.
+ * Copyright (c) 2024 Collabora Ltd.
+ *                    AngeloGioacchino Del Regno <[email protected]>
+ */
+
+#ifndef __DT_BINDINGS_INTERCONNECT_MEDIATEK_MT8183_H
+#define __DT_BINDINGS_INTERCONNECT_MEDIATEK_MT8183_H
+
+#define SLAVE_DDR_EMI		0
+#define MASTER_MCUSYS		1
+#define MASTER_MFG		2
+#define MASTER_MMSYS		3
+#define MASTER_MM_VPU		4
+#define MASTER_MM_DISP		5
+#define MASTER_MM_VDEC		6
+#define MASTER_MM_VENC		7
+#define MASTER_MM_CAM		8
+#define MASTER_MM_IMG		9
+#define MASTER_MM_MDP		10
+
+#endif

include/dt-bindings/interconnect/mediatek,mt8195.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2020 MediaTek Inc.
+ * Copyright (c) 2024 Collabora Ltd.
+ *                    AngeloGioacchino Del Regno <[email protected]>
+ */
+
+#ifndef __DT_BINDINGS_INTERCONNECT_MEDIATEK_MT8195_H
+#define __DT_BINDINGS_INTERCONNECT_MEDIATEK_MT8195_H
+
+#define SLAVE_DDR_EMI		0
+#define MASTER_MCUSYS		1
+#define MASTER_GPUSYS		2
+#define MASTER_MMSYS		3
+#define MASTER_MM_VPU		4
+#define MASTER_MM_DISP		5
+#define MASTER_MM_VDEC		6
+#define MASTER_MM_VENC		7
+#define MASTER_MM_CAM		8
+#define MASTER_MM_IMG		9
+#define MASTER_MM_MDP		10
+#define MASTER_VPUSYS		11
+#define MASTER_VPU_0		12
+#define MASTER_VPU_1		13
+#define MASTER_MDLASYS		14
+#define MASTER_MDLA_0		15
+#define MASTER_UFS		16
+#define MASTER_PCIE_0		17
+#define MASTER_PCIE_1		18
+#define MASTER_USB		19
+#define MASTER_DBGIF		20
+#define SLAVE_HRT_DDR_EMI	21
+#define MASTER_HRT_MMSYS	22
+#define MASTER_HRT_MM_DISP	23
+#define MASTER_HRT_MM_VDEC	24
+#define MASTER_HRT_MM_VENC	25
+#define MASTER_HRT_MM_CAM	26
+#define MASTER_HRT_MM_IMG	27
+#define MASTER_HRT_MM_MDP	28
+#define MASTER_HRT_DBGIF	29
+#define MASTER_WIFI		30
+#define MASTER_BT		31
+#define MASTER_NETSYS		32
+#endif