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