[PATCH v3 4/8] dt-bindings: add documentation of rk3036 clock controller

Xing Zheng
2015-09-29T02:17:53Z

Add the devicetree binding for the cru on the rk3036 which quite similar
structured as previous clock controllers.

Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
---

Changes in v3: None

.../bindings/clock/rockchip,rk3036-cru.txt | 56 ++++++++++++++++++++
1 file changed, 56 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt

diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt
new file mode 100644
index 0000000..ace0599
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt
@@ -0,0 +1,56 @@
+* Rockchip RK3036 Clock and Reset Unit
+
+The RK3036 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,rk3036-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/rk3036-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,
+ - "ext_gmac" - external GMAC clock - optional
+
+Example: Clock controller node:
+
+ cru: cru@20000000 {
+ compatible = "rockchip,rk3036-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:
+
+ uart0: serial@20060000 {
+ compatible = "snps,dw-apb-uart";
+ reg = <0x20060000 0x100>;
+ interrupts = <GIC_SPI 20 IRQ_TYPE_LEVEL_HIGH>;
+ reg-shift = <2>;
+ reg-io-width = <4>;
+ clocks = <&cru SCLK_UART0>;
+ };
--
1.7.9.5