dram_helpers.c
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/*
* DRAM init helper functions
*
* (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/barriers.h>
#include <asm/io.h>
#include <asm/arch/dram.h>
/*
* Wait up to 1s for value to be set in given part of reg.
*/
void mctl_await_completion(u32 *reg, u32 mask, u32 val)
{
unsigned long tmo = timer_get_us() + 1000000;
while ((readl(reg) & mask) != val) {
if (timer_get_us() > tmo)
panic("Timeout initialising DRAM\n");
}
}
/*
* Test if memory at offset offset matches memory at begin of DRAM
*/
bool mctl_mem_matches(u32 offset)
{
/* Try to write different values to RAM at two addresses */
writel(0, CONFIG_SYS_SDRAM_BASE);
writel(0xaa55aa55, (ulong)CONFIG_SYS_SDRAM_BASE + offset);
dsb();
/* Check if the same value is actually observed when reading back */
return readl(CONFIG_SYS_SDRAM_BASE) ==
readl((ulong)CONFIG_SYS_SDRAM_BASE + offset);
}