ddr.c 1.4 KB

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  1. /*
  2. * Copyright 2009 Freescale Semiconductor, Inc.
  3. *
  4. * This program is free software; you can redistribute it and/or
  5. * modify it under the terms of the GNU General Public License
  6. * Version 2 as published by the Free Software Foundation.
  7. */
  8. #include <common.h>
  9. #include <asm/fsl_ddr_sdram.h>
  10. #include <asm/fsl_ddr_dimm_params.h>
  11. void fsl_ddr_board_options(memctl_options_t *popts,
  12. dimm_params_t *pdimm,
  13. unsigned int ctrl_num)
  14. {
  15. /*
  16. * Factors to consider for clock adjust:
  17. * - number of chips on bus
  18. * - position of slot
  19. * - DDR1 vs. DDR2?
  20. * - ???
  21. *
  22. * This needs to be determined on a board-by-board basis.
  23. * 0110 3/4 cycle late
  24. * 0111 7/8 cycle late
  25. */
  26. popts->clk_adjust = 4;
  27. /*
  28. * Factors to consider for CPO:
  29. * - frequency
  30. * - ddr1 vs. ddr2
  31. */
  32. popts->cpo_override = 0xff;
  33. /*
  34. * Factors to consider for write data delay:
  35. * - number of DIMMs
  36. *
  37. * 1 = 1/4 clock delay
  38. * 2 = 1/2 clock delay
  39. * 3 = 3/4 clock delay
  40. * 4 = 1 clock delay
  41. * 5 = 5/4 clock delay
  42. * 6 = 3/2 clock delay
  43. */
  44. popts->write_data_delay = 2;
  45. /*
  46. * Enable half drive strength
  47. */
  48. popts->half_strength_driver_enable = 1;
  49. /* Write leveling override */
  50. popts->wrlvl_en = 1;
  51. popts->wrlvl_override = 1;
  52. popts->wrlvl_sample = 0xa;
  53. popts->wrlvl_start = 0x4;
  54. /* Rtt and Rtt_W override */
  55. popts->rtt_override = 1;
  56. popts->rtt_override_value = DDR3_RTT_60_OHM;
  57. popts->rtt_wr_override_value = 0; /* Rtt_WR= dynamic ODT off */
  58. }