linux/Documentation/devicetree/bindings/clock/ingenic,cgu.txt
Paul Cercueil 067b6dedeb dt-bindings: clock: ingenic: Explicitly list compatible strings
This is better than letting the other developers wondering what are the
supported strings.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-10-16 15:19:22 -07:00

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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 one of:
* ingenic,jz4740-cgu
* ingenic,jz4725b-cgu
* ingenic,jz4770-cgu
* 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";
};
};