linux/Documentation/devicetree/bindings/clock/ingenic,cgu.txt
Paul Burton fe4ef45b5b DEVICETREE: Add Ingenic CGU binding documentation
Document the devicetree binding for Ingenic SoC CGUs, and add headers
defining the clock specifiers for clocks provided by the JZ4740 & JZ4780
CGU blocks.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10152/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-21 21:53:13 +02:00

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Ingenic SoC CGU binding
The CGU in an Ingenic SoC provides all the clocks generated on-chip. It
typically includes a variety of PLLs, multiplexers, dividers & gates in order
to provide many different clock signals derived from only 2 external source
clocks.
Required properties:
- compatible : Should be "ingenic,<soctype>-cgu".
For example "ingenic,jz4740-cgu" or "ingenic,jz4780-cgu".
- reg : The address & length of the CGU registers.
- clocks : List of phandle & clock specifiers for clocks external to the CGU.
Two such external clocks should be specified - first the external crystal
"ext" and second the RTC clock source "rtc".
- clock-names : List of name strings for the external clocks.
- #clock-cells: Should be 1.
Clock consumers specify this argument to identify a clock. The valid values
may be found in <dt-bindings/clock/<soctype>-cgu.h>.
Example SoC include file:
/ {
cgu: jz4740-cgu {
compatible = "ingenic,jz4740-cgu";
reg = <0x10000000 0x100>;
#clock-cells = <1>;
};
uart0: serial@10030000 {
clocks = <&cgu JZ4740_CLK_UART0>;
};
};
Example board file:
/ {
ext: clock@0 {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <12000000>;
};
rtc: clock@1 {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <32768>;
};
&cgu {
clocks = <&ext> <&rtc>;
clock-names: "ext", "rtc";
};
};