clk: sunxi-ng: Add A80 Display Engine CCU

With the A80 SoC, Allwinner grouped and moved some subsystem specific
clock controls to a separate address space, and possibly separate
hardware block.

One such subsystem is the display engine. The main clock control unit
now only has 1 set of bus gate, dram gate, module clock, and reset
control for the entire display subsystem. These feed into a secondary
clock control unit, which has controls for each individual module
of the display pipeline. This block is not documented in the user
manual. Allwinner's kernel was used as the reference.

Add support for the display engine clock controls found on the A80.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/sun9i-de.txt b/Documentation/devicetree/bindings/clock/sun9i-de.txt
new file mode 100644
index 000000000000..fb18f327b97a
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/sun9i-de.txt
@@ -0,0 +1,28 @@
+Allwinner A80 Display Engine Clock Control Binding
+--------------------------------------------------
+
+Required properties :
+- compatible: must contain one of the following compatibles:
+		- "allwinner,sun9i-a80-de-clks"
+
+- reg: Must contain the registers base address and length
+- clocks: phandle to the clocks feeding the display engine subsystem.
+	  Three are needed:
+  - "mod": the display engine module clock
+  - "dram": the DRAM bus clock for the system
+  - "bus": the bus clock for the whole display engine subsystem
+- clock-names: Must contain the clock names described just above
+- resets: phandle to the reset control for the display engine subsystem.
+- #clock-cells : must contain 1
+- #reset-cells : must contain 1
+
+Example:
+de_clocks: clock@3000000 {
+	compatible = "allwinner,sun9i-a80-de-clks";
+	reg = <0x03000000 0x30>;
+	clocks = <&ccu CLK_DE>, <&ccu CLK_SDRAM>, <&ccu CLK_BUS_DE>;
+	clock-names = "mod", "dram", "bus";
+	resets = <&ccu RST_BUS_DE>;
+	#clock-cells = <1>;
+	#reset-cells = <1>;
+};