summaryrefslogtreecommitdiffstats
path: root/board/freescale/m5282evb/m5282evb.c
blob: 39f12fb4aa2db5b3812933aab4a751161eb3e124 (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
/*
 * (C) Copyright 2000-2003
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <asm/immap.h>

DECLARE_GLOBAL_DATA_PTR;

int checkboard (void)
{
	puts ("Board: Freescale M5282EVB Evaluation Board\n");
	return 0;
}

phys_size_t initdram (int board_type)
{
	u32 dramsize, i, dramclk;

	dramsize = CONFIG_SYS_SDRAM_SIZE * 0x100000;
	for (i = 0x13; i < 0x20; i++) {
		if (dramsize == (1 << i))
			break;
	}
	i--;

	if (!(MCFSDRAMC_DACR0 & MCFSDRAMC_DACR_RE))
	{
		dramclk = gd->bus_clk / (CONFIG_SYS_HZ * CONFIG_SYS_HZ);

		/* Initialize DRAM Control Register: DCR */
		MCFSDRAMC_DCR = (0
			| MCFSDRAMC_DCR_RTIM_6
			| MCFSDRAMC_DCR_RC((15 * dramclk)>>4));
		asm("nop");

		/* Initialize DACR0 */
		MCFSDRAMC_DACR0 = (0
			| MCFSDRAMC_DACR_BASE(CONFIG_SYS_SDRAM_BASE)
			| MCFSDRAMC_DACR_CASL(1)
			| MCFSDRAMC_DACR_CBM(3)
			| MCFSDRAMC_DACR_PS_32);
		asm("nop");

		/* Initialize DMR0 */
		MCFSDRAMC_DMR0 = (0
			| ((dramsize - 1) & 0xFFFC0000)
			| MCFSDRAMC_DMR_V);
		asm("nop");

		/* Set IP (bit 3) in DACR */
		MCFSDRAMC_DACR0 |= MCFSDRAMC_DACR_IP;
		asm("nop");

		/* Wait 30ns to allow banks to precharge */
		for (i = 0; i < 5; i++) {
			asm ("nop");
		}

		/* Write to this block to initiate precharge */
		*(u32 *)(CONFIG_SYS_SDRAM_BASE) = 0xA5A59696;
		asm("nop");

		/* Set RE (bit 15) in DACR */
		MCFSDRAMC_DACR0 |= MCFSDRAMC_DACR_RE;
		asm("nop");

		/* Wait for at least 8 auto refresh cycles to occur */
		for (i = 0; i < 2000; i++) {
			asm(" nop");
		}

		/* Finish the configuration by issuing the IMRS. */
		MCFSDRAMC_DACR0 |= MCFSDRAMC_DACR_IMRS;
		asm("nop");

		/* Write to the SDRAM Mode Register */
		*(u32 *)(CONFIG_SYS_SDRAM_BASE + 0x400) = 0xA5A59696;
	}
	return dramsize;
}
OpenPOWER on IntegriCloud