LXR uboot/arch/arm/mach-sunxi/dram

   1/*
   2 * DRAM init helper functions
   3 *
   4 * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
   5 *
   6 * SPDX-License-Identifier:     GPL-2.0+
   7 */
   8
   9#include <common.h>
  10#include <asm/barriers.h>
  11#include <asm/io.h>
  12#include <asm/arch/dram.h>
  13
  14/*
  15 * Wait up to 1s for value to be set in given part of reg.
  16 */
  17void mctl_await_completion(u32 *reg, u32 mask, u32 val)
  18{
  19        unsigned long tmo = timer_get_us() + 1000000;
  20
  21        while ((readl(reg) & mask) != val) {
  22                if (timer_get_us() > tmo)
  23                        panic("Timeout initialising DRAM\n");
  24        }
  25}
  26
  27/*
  28 * Test if memory at offset offset matches memory at begin of DRAM
  29 */
  30bool mctl_mem_matches(u32 offset)
  31{
  32        /* Try to write different values to RAM at two addresses */
  33        writel(0, CONFIG_SYS_SDRAM_BASE);
  34        writel(0xaa55aa55, (ulong)CONFIG_SYS_SDRAM_BASE + offset);
  35        dsb();
  36        /* Check if the same value is actually observed when reading back */
  37        return readl(CONFIG_SYS_SDRAM_BASE) ==
  38               readl((ulong)CONFIG_SYS_SDRAM_BASE + offset);
  39}
  40