dram_helpers.c 973 B

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * DRAM init helper functions
  4. *
  5. * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
  6. */
  7. #include <common.h>
  8. #include <time.h>
  9. #include <asm/barriers.h>
  10. #include <asm/io.h>
  11. #include <asm/arch/dram.h>
  12. /*
  13. * Wait up to 1s for value to be set in given part of reg.
  14. */
  15. void mctl_await_completion(u32 *reg, u32 mask, u32 val)
  16. {
  17. unsigned long tmo = timer_get_us() + 1000000;
  18. while ((readl(reg) & mask) != val) {
  19. if (timer_get_us() > tmo)
  20. panic("Timeout initialising DRAM\n");
  21. }
  22. }
  23. /*
  24. * Test if memory at offset offset matches memory at begin of DRAM
  25. */
  26. bool mctl_mem_matches(u32 offset)
  27. {
  28. /* Try to write different values to RAM at two addresses */
  29. writel(0, CONFIG_SYS_SDRAM_BASE);
  30. writel(0xaa55aa55, (ulong)CONFIG_SYS_SDRAM_BASE + offset);
  31. dsb();
  32. /* Check if the same value is actually observed when reading back */
  33. return readl(CONFIG_SYS_SDRAM_BASE) ==
  34. readl((ulong)CONFIG_SYS_SDRAM_BASE + offset);
  35. }