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+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/mediatek,mt8196-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek Functional Clock Controller for MT8196
+
+maintainers:
+ - Guangjie Song <guangjie.song@mediatek.com>
+ - Laura Nao <laura.nao@collabora.com>
+
+description: |
+ The clock architecture in MediaTek SoCs is structured like below:
+ PLLs -->
+ dividers -->
+ muxes
+ -->
+ clock gate
+
+ The device nodes provide clock gate control in different IP blocks.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - mediatek,mt8196-imp-iic-wrap-c
+ - mediatek,mt8196-imp-iic-wrap-e
+ - mediatek,mt8196-imp-iic-wrap-n
+ - mediatek,mt8196-imp-iic-wrap-w
+ - mediatek,mt8196-mdpsys0
+ - mediatek,mt8196-mdpsys1
+ - mediatek,mt8196-pericfg-ao
+ - mediatek,mt8196-pextp0cfg-ao
+ - mediatek,mt8196-pextp1cfg-ao
+ - mediatek,mt8196-ufscfg-ao
+ - mediatek,mt8196-vencsys
+ - mediatek,mt8196-vencsys-c1
+ - mediatek,mt8196-vencsys-c2
+ - mediatek,mt8196-vdecsys
+ - mediatek,mt8196-vdecsys-soc
+ - mediatek,mt8196-vdisp-ao
+ - const: syscon
+
+ reg:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 1
+
+ '#reset-cells':
+ const: 1
+ description:
+ Reset lines for PEXTP0/1 and UFS blocks.
+
+ mediatek,hardware-voter:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: |
+ Phandle to the "Hardware Voter" (HWV), as named in the vendor
+ documentation for MT8196/MT6991.
+
+ The HWV is a SoC-internal fixed-function MCU used to collect votes from
+ both the Application Processor and other remote processors within the SoC.
+ It is intended to transparently enable or disable hardware resources (such
+ as power domains or clocks) based on internal vote aggregation handled by
+ the MCU's internal state machine.
+
+ However, in practice, this design is incomplete. While the HWV performs
+ some internal vote aggregation,software is still required to
+ - Manually enable power supplies externally, if present and if required
+ - Manually enable parent clocks via direct MMIO writes to clock controllers
+ - Enable the FENC after the clock has been ungated via direct MMIO
+ writes to clock controllers
+
+ As such, the HWV behaves more like a hardware-managed clock reference
+ counter than a true voter. Furthermore, it is not a separate
+ controller. It merely serves as an alternative interface to the same
+ underlying clock or power controller. Actual control still requires
+ direct access to the controller's own MMIO register space, in
+ addition to writing to the HWV's MMIO region.
+
+ For this reason, a custom phandle is used here - drivers need to directly
+ access the HWV MMIO region in a syscon-like fashion, due to how the
+ hardware is wired. This differs from true hardware voting systems, which
+ typically do not require custom phandles and rely instead on generic APIs
+ (clocks, power domains, interconnects).
+
+ The name "hardware-voter" is retained to match vendor documentation, but
+ this should not be reused or misunderstood as a proper voting mechanism.
+
+required:
+ - compatible
+ - reg
+ - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ pericfg_ao: clock-controller@16640000 {
+ compatible = "mediatek,mt8196-pericfg-ao", "syscon";
+ reg = <0x16640000 0x1000>;
+ mediatek,hardware-voter = <&scp_hwv>;
+ #clock-cells = <1>;
+ };
+ - |
+ pextp0cfg_ao: clock-controller@169b0000 {
+ compatible = "mediatek,mt8196-pextp0cfg-ao", "syscon";
+ reg = <0x169b0000 0x1000>;
+ #clock-cells = <1>;
+ #reset-cells = <1>;
+ };