sram.txt 1.8 KB

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  1. Allwinnner SoC SRAM controllers
  2. -----------------------------------------------------
  3. The SRAM controller found on most Allwinner devices is represented by
  4. a regular node for the SRAM controller itself, with sub-nodes
  5. reprensenting the SRAM handled by the SRAM controller.
  6. Controller Node
  7. ---------------
  8. Required properties:
  9. - compatible : "allwinner,sun4i-a10-sram-controller"
  10. - reg : sram controller register offset + length
  11. SRAM nodes
  12. ----------
  13. Each SRAM is described using the mmio-sram bindings documented in
  14. Documentation/devicetree/bindings/misc/sram.txt
  15. Each SRAM will have SRAM sections that are going to be handled by the
  16. SRAM controller as subnodes. These sections are represented following
  17. once again the representation described in the mmio-sram binding.
  18. The valid sections compatible are:
  19. - allwinner,sun4i-a10-sram-a3-a4
  20. - allwinner,sun4i-a10-sram-d
  21. Devices using SRAM sections
  22. ---------------------------
  23. Some devices need to request to the SRAM controller to map an SRAM for
  24. their exclusive use.
  25. The relationship between such a device and an SRAM section is
  26. expressed through the allwinner,sram property, that will take a
  27. phandle and an argument.
  28. This valid values for this argument are:
  29. - 0: CPU
  30. - 1: Device
  31. Example
  32. -------
  33. sram-controller@01c00000 {
  34. compatible = "allwinner,sun4i-a10-sram-controller";
  35. reg = <0x01c00000 0x30>;
  36. #address-cells = <1>;
  37. #size-cells = <1>;
  38. ranges;
  39. sram_a: sram@00000000 {
  40. compatible = "mmio-sram";
  41. reg = <0x00000000 0xc000>;
  42. #address-cells = <1>;
  43. #size-cells = <1>;
  44. ranges = <0 0x00000000 0xc000>;
  45. emac_sram: sram-section@8000 {
  46. compatible = "allwinner,sun4i-a10-sram-a3-a4";
  47. reg = <0x8000 0x4000>;
  48. status = "disabled";
  49. };
  50. };
  51. };
  52. emac: ethernet@01c0b000 {
  53. compatible = "allwinner,sun4i-a10-emac";
  54. ...
  55. allwinner,sram = <&emac_sram 1>;
  56. };