Add devicetree bindings for Rockchip cru which found on
Rockchip SoCs.
Signed-off-by: Elaine Zhang <zhangqing@xxxxxxxxxxxxxx>
---
.../bindings/clock/rockchip,rk312x-cru.txt | 56 ++++++++++++++++++++++
1 file changed, 56 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/rockchip,rk312x-cru.txt
diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk312x-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk312x-cru.txt
new file mode 100644
index 000000000000..4a862fe9bea3
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/rockchip,rk312x-cru.txt
@@ -0,0 +1,56 @@
+* Rockchip RK312X Clock and Reset Unit
+
+The RK312X clock controller generates and supplies clock to various
+controllers within the SoC and also implements a reset controller for SoC
+peripherals.
+
+Required Properties:
+
+- compatible: should be "rockchip,rk312x-cru"
+- reg: physical base address of the controller and length of memory mapped
+ region.
+- #clock-cells: should be 1.
+- #reset-cells: should be 1.
+
+Optional Properties:
+
+- rockchip,grf: phandle to the syscon managing the "general register files"
+ If missing pll rates are not changeable, due to the missing pll lock status.
+
+Each clock is assigned an identifier and client nodes can use this identifier
+to specify the clock which they consume. All available clocks are defined as
+preprocessor macros in the dt-bindings/clock/rk312x-cru.h headers and can be
+used in device tree sources. Similar macros exist for the reset sources in
+these files.
+
+External clocks:
+
+There are several clocks that are generated outside the SoC. It is expected
+that they are defined using standard clock bindings with following
+clock-output-names:
+ - "xin24m" - crystal input - required,
+ - "ext_i2s" - external I2S clock - optional,
+ - "gmac_clkin" - external GMAC clock - optional
+
+Example: Clock controller node:
+
+ cru: cru@20000000 {
+ compatible = "rockchip,rk312x-cru";
+ reg = <0x20000000 0x1000>;
+ rockchip,grf = <&grf>;
+
+ #clock-cells = <1>;
+ #reset-cells = <1>;
+ };
+
+Example: UART controller node that consumes the clock generated by the clock
+ controller:
+
+uart2: serial@20068000 {
+ compatible = "rockchip,serial";
+ reg = <0x20068000 0x100>;
+ interrupts = <GIC_SPI 22 IRQ_TYPE_LEVEL_HIGH>;
+ clock-frequency = <24000000>;
+ clocks = <&cru SCLK_UART2>, <&cru PCLK_UART2>;
+ clock-names = "sclk_uart", "pclk_uart";
+ };
--
1.9.1
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