Documentation/devicetree/bindings/clock/ingenic,cgu.txt

   1 Ingenic SoC CGU binding
   2
   3 The CGU in an Ingenic SoC provides all the clocks generated on-chip. It
   4 typically includes a variety of PLLs, multiplexers, dividers & gates in order
   5 to provide many different clock signals derived from only 2 external source
   6 clocks.
   7
   8 Required properties:
   9 - compatible : Should be "ingenic,<soctype>-cgu".
  10   For example "ingenic,jz4740-cgu" or "ingenic,jz4780-cgu".
  11 - reg : The address & length of the CGU registers.
  12 - clocks : List of phandle & clock specifiers for clocks external to the CGU.
  13   Two such external clocks should be specified - first the external crystal
  14   "ext" and second the RTC clock source "rtc".
  15 - clock-names : List of name strings for the external clocks.
  16 - #clock-cells: Should be 1.
  17   Clock consumers specify this argument to identify a clock. The valid values
  18   may be found in <dt-bindings/clock/<soctype>-cgu.h>.
  19
  20 Example SoC include file:
  21
  22 / {
  23         cgu: jz4740-cgu {
  24                 compatible = "ingenic,jz4740-cgu";
  25                 reg = <0x10000000 0x100>;
  26                 #clock-cells = <1>;
  27         };
  28
  29         uart0: serial@10030000 {
  30                 clocks = <&cgu JZ4740_CLK_UART0>;
  31         };
  32 };
  33
  34 Example board file:
  35
  36 / {
  37         ext: clock@0 {
  38                 compatible = "fixed-clock";
  39                 #clock-cells = <0>;
  40                 clock-frequency = <12000000>;
  41         };
  42
  43         rtc: clock@1 {
  44                 compatible = "fixed-clock";
  45                 #clock-cells = <0>;
  46                 clock-frequency = <32768>;
  47         };
  48
  49         &cgu {
  50                 clocks = <&ext> <&rtc>;
  51                 clock-names: "ext", "rtc";
  52         };
  53 };