exynos-dw-mshc.txt 3.2 KB

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  1. * Samsung Exynos specific extensions to the Synopsys Designware Mobile
  2. Storage Host Controller
  3. The Synopsys designware mobile storage host controller is used to interface
  4. a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
  5. differences between the core Synopsys dw mshc controller properties described
  6. by synopsys-dw-mshc.txt and the properties used by the Samsung Exynos specific
  7. extensions to the Synopsys Designware Mobile Storage Host Controller.
  8. Required Properties:
  9. * compatible: should be
  10. - "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210
  11. specific extensions.
  12. - "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412
  13. specific extensions.
  14. - "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250
  15. specific extensions.
  16. - "samsung,exynos5420-dw-mshc": for controllers with Samsung Exynos5420
  17. specific extensions.
  18. * samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
  19. unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
  20. ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7.
  21. * samsung,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
  22. in transmit mode and CIU clock phase shift value in receive mode for single
  23. data rate mode operation. Refer notes below for the order of the cells and the
  24. valid values.
  25. * samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock phase shift value
  26. in transmit mode and CIU clock phase shift value in receive mode for double
  27. data rate mode operation. Refer notes below for the order of the cells and the
  28. valid values.
  29. Notes for the sdr-timing and ddr-timing values:
  30. The order of the cells should be
  31. - First Cell: CIU clock phase shift value for tx mode.
  32. - Second Cell: CIU clock phase shift value for rx mode.
  33. Valid values for SDR and DDR CIU clock timing for Exynos5250:
  34. - valid value for tx phase shift and rx phase shift is 0 to 7.
  35. - when CIU clock divider value is set to 3, all possible 8 phase shift
  36. values can be used.
  37. - if CIU clock divider value is 0 (that is divide by 1), both tx and rx
  38. phase shift clocks should be 0.
  39. Required properties for a slot (Deprecated - Recommend to use one slot per host):
  40. * gpios: specifies a list of gpios used for command, clock and data bus. The
  41. first gpio is the command line and the second gpio is the clock line. The
  42. rest of the gpios (depending on the bus-width property) are the data lines in
  43. no particular order. The format of the gpio specifier depends on the gpio
  44. controller.
  45. (Deprecated - Refer to Documentation/devicetree/binding/pinctrl/samsung-pinctrl.txt)
  46. Example:
  47. The MSHC controller node can be split into two portions, SoC specific and
  48. board specific portions as listed below.
  49. dwmmc0@12200000 {
  50. compatible = "samsung,exynos5250-dw-mshc";
  51. reg = <0x12200000 0x1000>;
  52. interrupts = <0 75 0>;
  53. #address-cells = <1>;
  54. #size-cells = <0>;
  55. };
  56. dwmmc0@12200000 {
  57. num-slots = <1>;
  58. cap-mmc-highspeed;
  59. cap-sd-highspeed;
  60. broken-cd;
  61. fifo-depth = <0x80>;
  62. card-detect-delay = <200>;
  63. samsung,dw-mshc-ciu-div = <3>;
  64. samsung,dw-mshc-sdr-timing = <2 3>;
  65. samsung,dw-mshc-ddr-timing = <1 2>;
  66. bus-width = <8>;
  67. };