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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* (C) Copyright 2000-2006
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/immap.h>
int checkboard (void) {
puts ("Board: iDMR\n");
return 0;
};
phys_size_t initdram (int board_type) {
int i;
/*
* After reset, CS0 is configured to cover entire address space. We
* need to configure it to its proper values, so that writes to
* CFG_SDRAM_BASE and vicinity during SDRAM controller setup below do
* now fall under CS0 (see 16.3.1 of the MCF5271 Reference Manual).
*/
/* Flash chipselect, CS0 */
/* ;CSAR0: Flash at 0xFF800000 */
mbar_writeShort(0x0080, 0xFF80);
/* CSCR0: Flash 6 waits, 16bit */
mbar_writeShort(0x008A, 0x1980);
/* CSMR0: Flash 8MB, R/W, valid */
mbar_writeLong(0x0084, 0x007F0001);
/*
* SDRAM configuration proper
*/
/*
* Address/Data Pin Assignment Reg.: enable address lines 23-21; do
* not enable data pins D[15:0], as we have 16 bit port to SDRAM
*/
mbar_writeByte(MCF_GPIO_PAR_AD,
MCF_GPIO_AD_ADDR23 |
MCF_GPIO_AD_ADDR22 |
MCF_GPIO_AD_ADDR21);
/* No need to configure BS pins - reset values are OK */
/* Chip Select Pin Assignment Reg.: set CS[1-7] to GPIO */
mbar_writeByte(MCF_GPIO_PAR_CS, 0x00);
/* SDRAM Control Pin Assignment Reg. */
mbar_writeByte(MCF_GPIO_PAR_SDRAM,
MCF_GPIO_SDRAM_CSSDCS_00 | /* no matter: PAR_CS=0 */
MCF_GPIO_SDRAM_SDWE |
MCF_GPIO_SDRAM_SCAS |
MCF_GPIO_SDRAM_SRAS |
MCF_GPIO_SDRAM_SCKE |
MCF_GPIO_SDRAM_SDCS_01);
/*
* Wait 100us. We run the bus at 50Mhz, one cycle is 20ns. So 5
* iterations will do, but we do 10 just to be safe.
*/
for (i = 0; i < 10; ++i)
asm(" nop");
/* 1. Initialize DRAM Control Register: DCR */
mbar_writeShort(MCF_SDRAMC_DCR,
MCF_SDRAMC_DCR_RTIM(0x10) | /* 65ns */
MCF_SDRAMC_DCR_RC(0x60)); /* 1562 cycles */
/*
* 2. Initialize DACR0
*
* CL: 11 (CL=3: 0x03, 0x02; CL=2: 0x1)
* CBM: cmd at A20, bank select bits 21 and up
* PS: 16 bit
*/
mbar_writeLong(MCF_SDRAMC_DACR0,
MCF_SDRAMC_DACRn_BA(CFG_SDRAM_BASE>>18) |
MCF_SDRAMC_DACRn_BA(0x00) |
MCF_SDRAMC_DACRn_CASL(0x03) |
MCF_SDRAMC_DACRn_CBM(0x03) |
MCF_SDRAMC_DACRn_PS(0x03));
/* Initialize DMR0 */
mbar_writeLong(MCF_SDRAMC_DMR0,
MCF_SDRAMC_DMRn_BAM_16M |
MCF_SDRAMC_DMRn_V);
/* 3. Set IP bit in DACR to initiate PALL command */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_IP);
/* Write to this block to initiate precharge */
*(volatile u16 *)(CFG_SDRAM_BASE) = 0xa5a5;
/*
* Wait at least 20ns to allow banks to precharge (t_RP = 20ns). We
* wait a wee longer, just to be safe.
*/
for (i = 0; i < 5; ++i)
asm(" nop");
/* 4. Set RE bit in DACR */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_RE);
/*
* Wait for at least 8 auto refresh cycles to occur, i.e. at least
* 781 bus cycles.
*/
for (i = 0; i < 1000; ++i)
asm(" nop");
/* Finish the configuration by issuing the MRS */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_MRS);
/*
* Write to the SDRAM Mode Register A0-A11 = 0x400
*
* Write Burst Mode = Programmed Burst Length
* Op Mode = Standard Op
* CAS Latency = 3
* Burst Type = Sequential
* Burst Length = 1
*/
*(volatile u32 *)(CFG_SDRAM_BASE + 0x1800) = 0xa5a5a5a5;
return CFG_SDRAM_SIZE * 1024 * 1024;
};
int testdram (void) {
/* TODO: XXX XXX XXX */
printf ("DRAM test not implemented!\n");
return (0);
}
|
