Re: [PATCH v2 5/9] dt-bindings: add documentation of rk3036 clock controller

From: Xing Zheng
Date: Wed Sep 23 2015 - 23:42:54 EST


On 2015å09æ17æ 23:09, Heiko StÃbner wrote:
Am Donnerstag, 17. September 2015, 18:32:49 schrieb Xing Zheng:
Add the devicetree binding for the cru on the rk3036 which quite similar
structured as previous clock controllers.

Signed-off-by: Xing Zheng<zhengxing@xxxxxxxxxxxxxx>
---

Changes in v2: None

.../bindings/clock/rockchip,rk3036-cru.txt | 60
++++++++++++++++++++ 1 file changed, 60 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..ac3037a
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/rockchip,rk3036-cru.txt
@@ -0,0 +1,60 @@
+* 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 changable, 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,
+ - "xin32k" - rtc clock - optional,
The rk3036 does not seem to use a rtc clock, so this should probably go away
Done.
+ - "ext_i2s" - external I2S clock - optional,
+ - "ext_hsadc" - external HSADC clock - optional,
+ - "ext_vip" - external VIP clock - optional,
+ - "ext_isp" - external ISP clock - optional,
+ - "ext_jtag" - external JTAG clock - optional
There do not seem to exist external clock sources for hsadc, vip, isp and jtag
in your clock tree?

missing here:
- ext_gmac
Yes, done.
+
+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>;
+ };
Thanks.

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