[PATCH 09/19] drm: sun4i: Add DT bindings documentation

[Maxime Ripard]

The display pipeline of the Allwinner A10 is involving several loosely
coupled components.

Add a documentation for the bindings.

Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
 .../devicetree/bindings/drm/sunxi/sun4i-drm.txt    | 122 +++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/drm/sunxi/sun4i-drm.txt

diff --git a/Documentation/devicetree/bindings/drm/sunxi/sun4i-drm.txt b/Documentation/devicetree/bindings/drm/sunxi/sun4i-drm.txt
new file mode 100644
index 000000000000..dbdccef787b4
--- /dev/null
+++ b/Documentation/devicetree/bindings/drm/sunxi/sun4i-drm.txt
@@ -0,0 +1,122 @@
+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
+
+TCON
+----
+
+The TCON acts as a CRTC and encoder for RGB / LVDS interfaces.
+
+Required properties:
+ - compatible: value should be "allwinner,sun4i-a10-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
+   - 'tcon-ch1': The clock driving the TCON channel 0
+
+ - clock-names: the clock names mentionned above
+ - clock-output-names: Name of the pixel clock created
+
+
+Display Engine Backend
+----------------------
+
+The display engine backend exposes layers and sprites to the
+system. It's split into two components, the frontend and backend, the
+frontend doing formats conversion, scaling, deinterlacing, while the
+backend actually manages the layers.
+
+Required properties:
+  - compatible: value must be one of:
+    * allwinner,sun5i-a13-display-engine
+
+  - reg: base address and size of the memory-mapped region. Two are needed:
+    * backend0: registers of the display engine backend
+    * frontend0: registers of the display engine frontend
+  - reg_names: the region names mentionned above.
+
+  - interrupts: frontend interrupt phandle
+
+  - clocks: phandles to the clocks feeding the frontend and backend
+    * backend0-bus: the backend interface clock
+    * backend0-mod: the backend module clock
+    * backend0-ram: the backend DRAM clock
+    * frontend0-bus: the frontend interface clock
+    * frontend0-mod: the frontend module clock
+    * frontend0-ram: the frontend DRAM clock
+  - clock-names: the clock names mentionned above
+
+  - resets: phandles to the reset controllers. Two are needed:
+    * backend0: backend reset controller
+    * frontend0: frontend reset controller
+  - reset-names: the reset names mentionned above
+
+  - allwinner,tcon: phandle to the TCON in our pipeline
+
+Optional properties:
+  - allwinner,tv-encoder: phandle to the TV Encoder in our pipeline
+  - allwinner,panel: phandle to the panel used in our RGB interface
+
+Example:
+
+panel: panel {
+	compatible = "olimex,lcd-olinuxino-43-ts";
+};
+
+tve: encoder at 01c0a000 {
+	compatible = "allwinner,sun4i-a10-tv-encoder";
+	reg = <0x01c0a000 0x1000>;
+	clocks = <&ahb_gates 34>;
+};
+
+tcon: lcd-controller at 01c0c000 {
+	compatible = "allwinner,sun4i-a10-tcon";
+	reg = <0x01c0c000 0x1000>;
+	interrupts = <44>;
+	clocks = <&ahb_gates 36>,
+		 <&tcon_ch0_clk>,
+		 <&tcon_ch1_clk>;
+	clock-names = "ahb",
+		      "tcon-ch0",
+		      "tcon-ch1";
+	clock-output-names = "tcon-pixel-clock";
+};
+
+de: display-engine at 01e00000 {
+	compatible = "allwinner,sun5i-a13-display-engine";
+	reg = <0x01e00000 0x20000>,
+	      <0x01e60000 0x10000>;
+	reg-names = "frontend0",
+		    "backend0";
+	interrupts = <47>;
+	interrupt-names = "engine0";
+	clocks = <&ahb_gates 46>, <&de_fe_clk>,
+		 <&dram_gates 25>, <&ahb_gates 44>,
+		 <&de_be_clk>, <&dram_gates 26>;
+	clock-names = "frontend0-bus", "frontend0-mod",
+		      "frontend0-ram", "backend0-bus",
+		      "backend0-mod", "backend0-ram";
+	resets = <&de_fe_clk>,
+		 <&de_be_clk>;
+	reset-names = "frontend0",
+		      "backend0";
+
+	allwinner,tcon = <&tcon>;
+	allwinner,tv-encoder = <&tve>;
+	allwinner,panel = <&panel>;
+};
-- 
2.6.2