1 /*
2  * (C) Copyright 2010
3  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <asm/io.h>
10 
11 DECLARE_GLOBAL_DATA_PTR;
12 
13 const ulong patterns[]      = {	0x00000000,
14 				0xFFFFFFFF,
15 				0xFF00FF00,
16 				0x0F0F0F0F,
17 				0xF0F0F0F0};
18 const ulong NBR_OF_PATTERNS = sizeof(patterns) / sizeof(*patterns);
19 const ulong OFFS_PATTERN    = 3;
20 const ulong REPEAT_PATTERN  = 1000;
21 
22 void bootcount_store(ulong a)
23 {
24 	ulong *save_addr;
25 	ulong size = 0;
26 	int i;
27 
28 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
29 		size += gd->bd->bi_dram[i].size;
30 	save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
31 	writel(a, save_addr);
32 	writel(BOOTCOUNT_MAGIC, &save_addr[1]);
33 
34 	for (i = 0; i < REPEAT_PATTERN; i++)
35 		writel(patterns[i % NBR_OF_PATTERNS],
36 			&save_addr[i + OFFS_PATTERN]);
37 
38 }
39 
40 ulong bootcount_load(void)
41 {
42 	ulong *save_addr;
43 	ulong size = 0;
44 	ulong counter = 0;
45 	int i, tmp;
46 
47 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++)
48 		size += gd->bd->bi_dram[i].size;
49 	save_addr = (ulong *)(size - BOOTCOUNT_ADDR);
50 
51 	counter = readl(&save_addr[0]);
52 
53 	/* Is the counter reliable, check in the big pattern for bit errors */
54 	for (i = 0; (i < REPEAT_PATTERN) && (counter != 0); i++) {
55 		tmp = readl(&save_addr[i + OFFS_PATTERN]);
56 		if (tmp != patterns[i % NBR_OF_PATTERNS])
57 			counter = 0;
58 	}
59 	return counter;
60 }
61