dt-bindings: add documentation for s3c2412 clock controller

Describe the clock controller of the s3c2412.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This commit is contained in:
Heiko Stuebner 2014-02-25 09:50:44 +09:00 committed by Kukjin Kim
parent ea5d6a8d3e
commit 7d03fed8e5

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* Samsung S3C2412 Clock Controller
The S3C2412 clock controller generates and supplies clock to various controllers
within the SoC. The clock binding described here is applicable to the s3c2412
and s3c2413 SoCs in the s3c24x family.
Required Properties:
- compatible: should be "samsung,s3c2412-clock"
- reg: physical base address of the controller and length of memory mapped
region.
- #clock-cells: should be 1.
Each clock is assigned an identifier and client nodes can use this identifier
to specify the clock which they consume. Some of the clocks are available only
on a particular SoC.
All available clocks are defined as preprocessor macros in
dt-bindings/clock/s3c2412.h header and can be used in device
tree sources.
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:
- "xti" - crystal input - required,
- "ext" - external clock source - optional,
Example: Clock controller node:
clocks: clock-controller@4c000000 {
compatible = "samsung,s3c2412-clock";
reg = <0x4c000000 0x20>;
#clock-cells = <1>;
};
Example: UART controller node that consumes the clock generated by the clock
controller (refer to the standard clock bindings for information about
"clocks" and "clock-names" properties):
serial@50004000 {
compatible = "samsung,s3c2412-uart";
reg = <0x50004000 0x4000>;
interrupts = <1 23 3 4>, <1 23 4 4>;
clock-names = "uart", "clk_uart_baud2", "clk_uart_baud3";
clocks = <&clocks PCLK_UART0>, <&clocks PCLK_UART0>,
<&clocks SCLK_UART>;
status = "disabled";
};