[media] dt-bindings: Add a binding for Mediatek Video Encoder

Add a DT binding documentation of Video Encoder for the
MT8173 SoC from Mediatek.
Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/devicetree/bindings/media/mediatek-vcodec.txt

+Mediatek Video Codec
+
+Mediatek Video Codec is the video codec hw present in Mediatek SoCs which
+supports high resolution encoding functionalities.
+
+Required properties:
+- compatible : "mediatek,mt8173-vcodec-enc" for encoder
+- reg : Physical base address of the video codec registers and length of
+  memory mapped region.
+- interrupts : interrupt number to the cpu.
+- mediatek,larb : must contain the local arbiters in the current Socs.
+- clocks : list of clock specifiers, corresponding to entries in
+  the clock-names property.
+- clock-names: encoder must contain "venc_sel_src", "venc_sel",
+- "venc_lt_sel_src", "venc_lt_sel".
+- iommus : should point to the respective IOMMU block with master port as
+  argument, see Documentation/devicetree/bindings/iommu/mediatek,iommu.txt
+  for details.
+- mediatek,vpu : the node of video processor unit
+
+Example:
+vcodec_enc: vcodec@0x18002000 {
+    compatible = "mediatek,mt8173-vcodec-enc";
+    reg = <0 0x18002000 0 0x1000>,    /*VENC_SYS*/
+          <0 0x19002000 0 0x1000>;    /*VENC_LT_SYS*/
+    interrupts = <GIC_SPI 198 IRQ_TYPE_LEVEL_LOW>,
+		 <GIC_SPI 202 IRQ_TYPE_LEVEL_LOW>;
+    mediatek,larb = <&larb3>,
+		    <&larb5>;
+    iommus = <&iommu M4U_PORT_VENC_RCPU>,
+             <&iommu M4U_PORT_VENC_REC>,
+             <&iommu M4U_PORT_VENC_BSDMA>,
+             <&iommu M4U_PORT_VENC_SV_COMV>,
+             <&iommu M4U_PORT_VENC_RD_COMV>,
+             <&iommu M4U_PORT_VENC_CUR_LUMA>,
+             <&iommu M4U_PORT_VENC_CUR_CHROMA>,
+             <&iommu M4U_PORT_VENC_REF_LUMA>,
+             <&iommu M4U_PORT_VENC_REF_CHROMA>,
+             <&iommu M4U_PORT_VENC_NBM_RDMA>,
+             <&iommu M4U_PORT_VENC_NBM_WDMA>,
+             <&iommu M4U_PORT_VENC_RCPU_SET2>,
+             <&iommu M4U_PORT_VENC_REC_FRM_SET2>,
+             <&iommu M4U_PORT_VENC_BSDMA_SET2>,
+             <&iommu M4U_PORT_VENC_SV_COMA_SET2>,
+             <&iommu M4U_PORT_VENC_RD_COMA_SET2>,
+             <&iommu M4U_PORT_VENC_CUR_LUMA_SET2>,
+             <&iommu M4U_PORT_VENC_CUR_CHROMA_SET2>,
+             <&iommu M4U_PORT_VENC_REF_LUMA_SET2>,
+             <&iommu M4U_PORT_VENC_REC_CHROMA_SET2>;
+    mediatek,vpu = <&vpu>;
+    clocks = <&topckgen CLK_TOP_VENCPLL_D2>,
+             <&topckgen CLK_TOP_VENC_SEL>,
+             <&topckgen CLK_TOP_UNIVPLL1_D2>,
+             <&topckgen CLK_TOP_VENC_LT_SEL>;
+    clock-names = "venc_sel_src",
+                  "venc_sel",
+                  "venc_lt_sel_src",
+                  "venc_lt_sel";
+  };