113 lines
3.7 KiB
Plaintext
113 lines
3.7 KiB
Plaintext
Amlogic Meson Display Controller
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================================
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The Amlogic Meson Display controller is composed of several components
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that are going to be documented below:
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DMC|---------------VPU (Video Processing Unit)----------------|------HHI------|
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| vd1 _______ _____________ _________________ | |
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D |-------| |----| | | | | HDMI PLL |
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D | vd2 | VIU | | Video Post | | Video Encoders |<---|-----VCLK |
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R |-------| |----| Processing | | | | |
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| osd2 | | | |---| Enci ----------|----|-----VDAC------|
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R |-------| CSC |----| Scalers | | Encp ----------|----|----HDMI-TX----|
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A | osd1 | | | Blenders | | Encl ----------|----|---------------|
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M |-------|______|----|____________| |________________| | |
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___|__________________________________________________________|_______________|
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VIU: Video Input Unit
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---------------------
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The Video Input Unit is in charge of the pixel scanout from the DDR memory.
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It fetches the frames addresses, stride and parameters from the "Canvas" memory.
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This part is also in charge of the CSC (Colorspace Conversion).
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It can handle 2 OSD Planes and 2 Video Planes.
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VPP: Video Post Processing
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--------------------------
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The Video Post Processing is in charge of the scaling and blending of the
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various planes into a single pixel stream.
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There is a special "pre-blending" used by the video planes with a dedicated
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scaler and a "post-blending" to merge with the OSD Planes.
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The OSD planes also have a dedicated scaler for one of the OSD.
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VENC: Video Encoders
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--------------------
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The VENC is composed of the multiple pixel encoders :
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- ENCI : Interlace Video encoder for CVBS and Interlace HDMI
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- ENCP : Progressive Video Encoder for HDMI
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- ENCL : LCD LVDS Encoder
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The VENC Unit gets a Pixel Clocks (VCLK) from a dedicated HDMI PLL and clock
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tree and provides the scanout clock to the VPP and VIU.
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The ENCI is connected to a single VDAC for Composite Output.
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The ENCI and ENCP are connected to an on-chip HDMI Transceiver.
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Device Tree Bindings:
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---------------------
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VPU: Video Processing Unit
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--------------------------
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Required properties:
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- compatible: value should be different for each SoC family as :
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- GXBB (S905) : "amlogic,meson-gxbb-vpu"
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- GXL (S905X, S905D) : "amlogic,meson-gxl-vpu"
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- GXM (S912) : "amlogic,meson-gxm-vpu"
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followed by the common "amlogic,meson-gx-vpu"
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- reg: base address and size of he following memory-mapped regions :
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- vpu
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- hhi
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- dmc
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- reg-names: should contain the names of the previous memory regions
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- interrupts: should contain the VENC Vsync interrupt number
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Required nodes:
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The connections to the VPU output video ports are modeled using the OF graph
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bindings specified in Documentation/devicetree/bindings/graph.txt.
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The following table lists for each supported model the port number
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corresponding to each VPU output.
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Port 0 Port 1
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-----------------------------------------
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S905 (GXBB) CVBS VDAC HDMI-TX
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S905X (GXL) CVBS VDAC HDMI-TX
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S905D (GXL) CVBS VDAC HDMI-TX
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S912 (GXM) CVBS VDAC HDMI-TX
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Example:
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tv-connector {
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compatible = "composite-video-connector";
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port {
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tv_connector_in: endpoint {
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remote-endpoint = <&cvbs_vdac_out>;
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};
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};
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};
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vpu: vpu@d0100000 {
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compatible = "amlogic,meson-gxbb-vpu";
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reg = <0x0 0xd0100000 0x0 0x100000>,
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<0x0 0xc883c000 0x0 0x1000>,
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<0x0 0xc8838000 0x0 0x1000>;
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reg-names = "vpu", "hhi", "dmc";
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interrupts = <GIC_SPI 3 IRQ_TYPE_EDGE_RISING>;
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#address-cells = <1>;
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#size-cells = <0>;
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/* CVBS VDAC output port */
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port@0 {
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reg = <0>;
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cvbs_vdac_out: endpoint {
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remote-endpoint = <&tv_connector_in>;
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};
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};
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};
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