sram.txt 1.8 KB

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  1. Generic on-chip SRAM
  2. Simple IO memory regions to be managed by the genalloc API.
  3. Required properties:
  4. - compatible : mmio-sram
  5. - reg : SRAM iomem address range
  6. Reserving sram areas:
  7. ---------------------
  8. Each child of the sram node specifies a region of reserved memory. Each
  9. child node should use a 'reg' property to specify a specific range of
  10. reserved memory.
  11. Following the generic-names recommended practice, node names should
  12. reflect the purpose of the node. Unit address (@<address>) should be
  13. appended to the name.
  14. Required properties in the sram node:
  15. - #address-cells, #size-cells : should use the same values as the root node
  16. - ranges : standard definition, should translate from local addresses
  17. within the sram to bus addresses
  18. Required properties in the area nodes:
  19. - reg : iomem address range, relative to the SRAM range
  20. Optional properties in the area nodes:
  21. - compatible : standard definition, should contain a vendor specific string
  22. in the form <vendor>,[<device>-]<usage>
  23. - pool : indicates that the particular reserved SRAM area is addressable
  24. and in use by another device or devices
  25. - export : indicates that the reserved SRAM area may be accessed outside
  26. of the kernel, e.g. by bootloader or userspace
  27. - label : the name for the reserved partition, if omitted, the label
  28. is taken from the node name excluding the unit address.
  29. Example:
  30. sram: sram@5c000000 {
  31. compatible = "mmio-sram";
  32. reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
  33. #adress-cells = <1>;
  34. #size-cells = <1>;
  35. ranges = <0 0x5c000000 0x40000>;
  36. smp-sram@100 {
  37. compatible = "socvendor,smp-sram";
  38. reg = <0x100 0x50>;
  39. };
  40. device-sram@1000 {
  41. reg = <0x1000 0x1000>;
  42. pool;
  43. };
  44. exported@20000 {
  45. reg = <0x20000 0x20000>;
  46. export;
  47. };
  48. };