Allwinner A10 Display Pipeline
==============================

The Allwinner A10 Display pipeline is composed of several components
that are going to be documented below:

TV Encoder
----------

The TV Encoder supports the composite and VGA output. It is one end of
the pipeline.

Required properties:
 - compatible: value should be "allwinner,sun4i-a10-tv-encoder".
 - reg: base address and size of memory-mapped region
 - clocks: the clocks driving the TV encoder
 - resets: phandle to the reset controller driving the encoder

- ports: A ports node with endpoint definitions as defined in
  Documentation/devicetree/bindings/media/video-interfaces.txt. The
  first port should be the input endpoint.

TCON
----

The TCON acts as a timing controller for RGB, LVDS and TV interfaces.

Required properties:
 - compatible: value must be either:
   * allwinner,sun5i-a13-tcon
   * allwinner,sun8i-a33-tcon
 - reg: base address and size of memory-mapped region
 - interrupts: interrupt associated to this IP
 - clocks: phandles to the clocks feeding the TCON. Three are needed:
   - 'ahb': the interface clocks
   - 'tcon-ch0': The clock driving the TCON channel 0
 - resets: phandles to the reset controllers driving the encoder
   - "lcd": the reset line for the TCON channel 0

 - clock-names: the clock names mentioned above
 - reset-names: the reset names mentioned above
 - clock-output-names: Name of the pixel clock created

- ports: A ports node with endpoint definitions as defined in
  Documentation/devicetree/bindings/media/video-interfaces.txt. The
  first port should be the input endpoint, the second one the output

  The output should have two endpoints. The first is the block
  connected to the TCON channel 0 (usually a panel or a bridge), the
  second the block connected to the TCON channel 1 (usually the TV
  encoder)

On the A13, there is one more clock required:
   - 'tcon-ch1': The clock driving the TCON channel 1

DRC
---

The DRC (Dynamic Range Controller), found in the latest Allwinner SoCs
(A31, A23, A33), allows to dynamically adjust pixel
brightness/contrast based on histogram measurements for LCD content
adaptive backlight control.


Required properties:
  - compatible: value must be one of:
    * allwinner,sun8i-a33-drc
  - reg: base address and size of the memory-mapped region.
  - interrupts: interrupt associated to this IP
  - clocks: phandles to the clocks feeding the DRC
    * ahb: the DRC interface clock
    * mod: the DRC module clock
    * ram: the DRC DRAM clock
  - clock-names: the clock names mentioned above
  - resets: phandles to the reset line driving the DRC

- ports: A ports node with endpoint definitions as defined in
  Documentation/devicetree/bindings/media/video-interfaces.txt. The
  first port should be the input endpoints, the second one the outputs

Display Engine Backend
----------------------

The display engine backend exposes layers and sprites to the
system.

Required properties:
  - compatible: value must be one of:
    * allwinner,sun5i-a13-display-backend
    * allwinner,sun8i-a33-display-backend
  - reg: base address and size of the memory-mapped region.
  - clocks: phandles to the clocks feeding the frontend and backend
    * ahb: the backend interface clock
    * mod: the backend module clock
    * ram: the backend DRAM clock
  - clock-names: the clock names mentioned above
  - resets: phandles to the reset controllers driving the backend

- ports: A ports node with endpoint definitions as defined in
  Documentation/devicetree/bindings/media/video-interfaces.txt. The
  first port should be the input endpoints, the second one the output

On the A33, some additional properties are required:
  - reg needs to have an additional region corresponding to the SAT
  - reg-names need to be set, with "be" and "sat"
  - clocks and clock-names need to have a phandle to the SAT bus
    clocks, whose name will be "sat"
  - resets and reset-names need to have a phandle to the SAT bus
    resets, whose name will be "sat"

Display Engine Frontend
-----------------------

The display engine frontend does formats conversion, scaling,
deinterlacing and color space conversion.

Required properties:
  - compatible: value must be one of:
    * allwinner,sun5i-a13-display-frontend
    * allwinner,sun8i-a33-display-frontend
  - reg: base address and size of the memory-mapped region.
  - interrupts: interrupt associated to this IP
  - clocks: phandles to the clocks feeding the frontend and backend
    * ahb: the backend interface clock
    * mod: the backend module clock
    * ram: the backend DRAM clock
  - clock-names: the clock names mentioned above
  - resets: phandles to the reset controllers driving the backend

- ports: A ports node with endpoint definitions as defined in
  Documentation/devicetree/bindings/media/video-interfaces.txt. The
  first port should be the input endpoints, the second one the outputs


Display Engine Pipeline
-----------------------

The display engine pipeline (and its entry point, since it can be
either directly the backend or the frontend) is represented as an
extra node.

Required properties:
  - compatible: value must be one of:
    * allwinner,sun5i-a13-display-engine
    * allwinner,sun8i-a33-display-engine

  - allwinner,pipelines: list of phandle to the display engine
    frontends available.

Example:

panel: panel {
	compatible = "olimex,lcd-olinuxino-43-ts";
	#address-cells = <1>;
	#size-cells = <0>;

	port {
		#address-cells = <1>;
		#size-cells = <0>;

		panel_input: endpoint {
			remote-endpoint = <&tcon0_out_panel>;
		};
	};
};

tve0: tv-encoder@01c0a000 {
	compatible = "allwinner,sun4i-a10-tv-encoder";
	reg = <0x01c0a000 0x1000>;
	clocks = <&ahb_gates 34>;
	resets = <&tcon_ch0_clk 0>;

	port {
		#address-cells = <1>;
		#size-cells = <0>;

		tve0_in_tcon0: endpoint@0 {
			reg = <0>;
			remote-endpoint = <&tcon0_out_tve0>;
		};
	};
};

tcon0: lcd-controller@1c0c000 {
	compatible = "allwinner,sun5i-a13-tcon";
	reg = <0x01c0c000 0x1000>;
	interrupts = <44>;
	resets = <&tcon_ch0_clk 1>;
	reset-names = "lcd";
	clocks = <&ahb_gates 36>,
		 <&tcon_ch0_clk>,
		 <&tcon_ch1_clk>;
	clock-names = "ahb",
		      "tcon-ch0",
		      "tcon-ch1";
	clock-output-names = "tcon-pixel-clock";

	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		tcon0_in: port@0 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <0>;

			tcon0_in_be0: endpoint@0 {
				reg = <0>;
				remote-endpoint = <&be0_out_tcon0>;
			};
		};

		tcon0_out: port@1 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <1>;

			tcon0_out_panel: endpoint@0 {
				reg = <0>;
				remote-endpoint = <&panel_input>;
			};

			tcon0_out_tve0: endpoint@1 {
				reg = <1>;
				remote-endpoint = <&tve0_in_tcon0>;
			};
		};
	};
};

fe0: display-frontend@1e00000 {
	compatible = "allwinner,sun5i-a13-display-frontend";
	reg = <0x01e00000 0x20000>;
	interrupts = <47>;
	clocks = <&ahb_gates 46>, <&de_fe_clk>,
		 <&dram_gates 25>;
	clock-names = "ahb", "mod",
		      "ram";
	resets = <&de_fe_clk>;

	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		fe0_out: port@1 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <1>;

			fe0_out_be0: endpoint {
				remote-endpoint = <&be0_in_fe0>;
			};
		};
	};
};

be0: display-backend@1e60000 {
	compatible = "allwinner,sun5i-a13-display-backend";
	reg = <0x01e60000 0x10000>;
	clocks = <&ahb_gates 44>, <&de_be_clk>,
		 <&dram_gates 26>;
	clock-names = "ahb", "mod",
		      "ram";
	resets = <&de_be_clk>;

	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		be0_in: port@0 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <0>;

			be0_in_fe0: endpoint@0 {
				reg = <0>;
				remote-endpoint = <&fe0_out_be0>;
			};
		};

		be0_out: port@1 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <1>;

			be0_out_tcon0: endpoint@0 {
				reg = <0>;
				remote-endpoint = <&tcon0_in_be0>;
			};
		};
	};
};

display-engine {
	compatible = "allwinner,sun5i-a13-display-engine";
	allwinner,pipelines = <&fe0>;
};