ingenic,cgu.txt 1.3 KB

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