summaryrefslogtreecommitdiff
path: root/arch/arm/cpu/arm926ejs/pantheon/dram.c
blob: bbca7eef16dd8b8fdaf1a6d2be0633014ed6e371 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * (C) Copyright 2011
 * Marvell Semiconductor <www.marvell.com>
 * Written-by: Lei Wen <leiwen@marvell.com>,
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA
 */

#include <common.h>
#include <asm/arch/pantheon.h>

DECLARE_GLOBAL_DATA_PTR;

/*
 * Pantheon DRAM controller supports upto 8 banks
 * for chip select 0 and 1
 */

/*
 * DDR Memory Control Registers
 * Refer Datasheet 4.4
 */
struct panthddr_map_registers {
	u32	cs;	/* Memory Address Map Register -CS */
	u32	pad[3];
};

struct panthddr_registers {
	u8	pad[0x100 - 0x000];
	struct panthddr_map_registers mmap[2];
};

/*
 * panth_sdram_base - reads SDRAM Base Address Register
 */
u32 panth_sdram_base(int chip_sel)
{
	struct panthddr_registers *ddr_regs =
		(struct panthddr_registers *)PANTHEON_DRAM_BASE;
	u32 result = 0;
	u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);

	if (!CS_valid)
		return 0;

	result = readl(&ddr_regs->mmap[chip_sel].cs) & 0xFF800000;
	return result;
}

/*
 * panth_sdram_size - reads SDRAM size
 */
u32 panth_sdram_size(int chip_sel)
{
	struct panthddr_registers *ddr_regs =
		(struct panthddr_registers *)PANTHEON_DRAM_BASE;
	u32 result = 0;
	u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);

	if (!CS_valid)
		return 0;

	result = readl(&ddr_regs->mmap[chip_sel].cs);
	result = (result >> 16) & 0xF;
	if (result < 0x7) {
		printf("Unknown DRAM Size\n");
		return -1;
	} else {
		return ((0x8 << (result - 0x7)) * 1024 * 1024);
	}
}

#ifndef CONFIG_SYS_BOARD_DRAM_INIT
int dram_init(void)
{
	int i;

	gd->ram_size = 0;
	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
		gd->bd->bi_dram[i].start = panth_sdram_base(i);
		gd->bd->bi_dram[i].size = panth_sdram_size(i);
		/*
		 * It is assumed that all memory banks are consecutive
		 * and without gaps.
		 * If the gap is found, ram_size will be reported for
		 * consecutive memory only
		 */
		if (gd->bd->bi_dram[i].start != gd->ram_size)
			break;

		gd->ram_size += gd->bd->bi_dram[i].size;

	}

	for (; i < CONFIG_NR_DRAM_BANKS; i++) {
		/*
		 * If above loop terminated prematurely, we need to set
		 * remaining banks' start address & size as 0. Otherwise other
		 * u-boot functions and Linux kernel gets wrong values which
		 * could result in crash
		 */
		gd->bd->bi_dram[i].start = 0;
		gd->bd->bi_dram[i].size = 0;
	}
	return 0;
}

/*
 * If this function is not defined here,
 * board.c alters dram bank zero configuration defined above.
 */
void dram_init_banksize(void)
{
	dram_init();
}
#endif /* CONFIG_SYS_BOARD_DRAM_INIT */