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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
|
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2007-2008 coresystems GmbH
*
* 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; version 2 of the License.
*
* 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.
*/
#include <console/console.h>
#include <arch/io.h>
#include "raminit.h"
#include "i945.h"
/**
* sample the strobes signal
*/
static u32 sample_strobes(int channel_offset, struct sys_info *sysinfo)
{
u32 reg32, addr;
int i;
MCHBAR32(C0DRC1 + channel_offset) |= (1 << 6);
MCHBAR32(C0DRC1 + channel_offset) &= ~(1 << 6);
addr = 0;
if (channel_offset != 0) { /* must be dual channel */
if (sysinfo->interleaved == 1)
addr |= (1 << 6);
else
addr = ((u32)MCHBAR8(C0DRB3)) << 25;
}
for (i = 0; i < 28; i++) {
read32((void *)addr);
read32((void *)(addr + 0x80));
}
reg32 = MCHBAR32(RCVENMT);
if (channel_offset == 0)
reg32 = reg32 << 2;
/**
* [19] = 1: all bits are high
* [18] = 1: all bits are low
* [19:18] = 00: bits are mixed high, low
*/
return reg32;
}
/**
* This function sets receive enable coarse and medium timing parameters
*/
static void set_receive_enable(int channel_offset, u8 medium, u8 coarse)
{
u32 reg32;
printk(BIOS_SPEW, " set_receive_enable() medium=0x%x, coarse=0x%x\n", medium, coarse);
reg32 = MCHBAR32(C0DRT1 + channel_offset);
reg32 &= 0xf0ffffff;
reg32 |= ((u32)coarse & 0x0f) << 24;
MCHBAR32(C0DRT1 + channel_offset) = reg32;
/* This should never happen: */
if (coarse > 0x0f)
printk(BIOS_DEBUG, "set_receive_enable: coarse overflow: 0x%02x.\n", coarse);
/* medium control
*
* 00 - 1/4 clock
* 01 - 1/2 clock
* 10 - 3/4 clock
* 11 - 1 clock
*/
reg32 = MCHBAR32(RCVENMT);
if (!channel_offset) {
/* Channel 0 */
reg32 &= ~(3 << 2);
reg32 |= medium << 2;
} else {
/* Channel 1 */
reg32 &= ~(3 << 0);
reg32 |= medium;
}
MCHBAR32(RCVENMT) = reg32;
}
static int normalize(int channel_offset, u8 *mediumcoarse, u8 *fine)
{
printk(BIOS_SPEW, " normalize()\n");
if (*fine < 0x80)
return 0;
*fine -= 0x80;
*mediumcoarse += 1;
if (*mediumcoarse >= 0x40) {
printk(BIOS_DEBUG, "Normalize Error\n");
return -1;
}
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
MCHBAR8(C0WL0REOST + channel_offset) = *fine;
return 0;
}
static int find_preamble(int channel_offset, u8 *mediumcoarse,
struct sys_info *sysinfo)
{
/* find start of the data phase */
u32 reg32;
printk(BIOS_SPEW, " find_preamble()\n");
do {
if (*mediumcoarse < 4) {
printk(BIOS_DEBUG, "No Preamble found.\n");
return -1;
}
*mediumcoarse -= 4;
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
reg32 = sample_strobes(channel_offset, sysinfo);
} while (reg32 & (1 << 19));
if (!(reg32 & (1 << 18))) {
printk(BIOS_DEBUG, "No Preamble found (neither high nor low).\n");
return -1;
}
return 0;
}
/**
* add a quarter clock to the current receive enable settings
*/
static int add_quarter_clock(int channel_offset, u8 *mediumcoarse, u8 *fine)
{
printk(BIOS_SPEW, " add_quarter_clock() mediumcoarse=%02x fine=%02x\n",
*mediumcoarse, *fine);
if (*fine >= 0x80) {
*fine -= 0x80;
*mediumcoarse += 2;
if (*mediumcoarse >= 0x40) {
printk(BIOS_DEBUG, "clocks at max.\n");
return -1;
}
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
} else {
*fine += 0x80;
}
MCHBAR8(C0WL0REOST + channel_offset) = *fine;
return 0;
}
static int find_strobes_low(int channel_offset, u8 *mediumcoarse, u8 *fine,
struct sys_info *sysinfo)
{
u32 rcvenmt;
printk(BIOS_SPEW, " find_strobes_low()\n");
for (;;) {
MCHBAR8(C0WL0REOST + channel_offset) = *fine;
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
rcvenmt = sample_strobes(channel_offset, sysinfo);
if (((rcvenmt & (1 << 18)) != 0))
return 0;
*fine -= 0x80;
if (*fine == 0)
continue;
*mediumcoarse -= 2;
if (*mediumcoarse < 0xfe)
continue;
break;
}
printk(BIOS_DEBUG, "Could not find low strobe\n");
return 0;
}
static int find_strobes_edge(int channel_offset, u8 *mediumcoarse, u8 *fine,
struct sys_info *sysinfo)
{
int counter;
u32 rcvenmt;
printk(BIOS_SPEW, " find_strobes_edge()\n");
counter = 8;
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
for (;;) {
MCHBAR8(C0WL0REOST + channel_offset) = *fine;
rcvenmt = sample_strobes(channel_offset, sysinfo);
if ((rcvenmt & (1 << 19)) == 0) {
counter = 8;
} else {
counter--;
if (!counter)
break;
}
*fine = *fine + 1;
if (*fine < 0xf8) {
if (*fine & (1 << 3)) {
*fine &= ~(1 << 3);
*fine += 0x10;
}
continue;
}
*fine = 0;
*mediumcoarse += 2;
if (*mediumcoarse <= 0x40) {
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
continue;
}
printk(BIOS_DEBUG, "Could not find rising edge.\n");
return -1;
}
*fine -= 7;
if (*fine >= 0xf9) {
*mediumcoarse -= 2;
set_receive_enable(channel_offset, *mediumcoarse & 3,
*mediumcoarse >> 2);
}
*fine &= ~(1 << 3);
MCHBAR8(C0WL0REOST + channel_offset) = *fine;
return 0;
}
/**
* Here we use a trick. The RCVEN channel 0 registers are all at an
* offset of 0x80 to the channel 0 registers. We don't want to waste
* a lot of if ()s so let's just pass 0 or 0x80 for the channel offset.
*/
static int receive_enable_autoconfig(int channel_offset,
struct sys_info *sysinfo)
{
u8 mediumcoarse;
u8 fine;
printk(BIOS_SPEW, "receive_enable_autoconfig() for channel %d\n",
channel_offset ? 1 : 0);
/* Set initial values */
mediumcoarse = (sysinfo->cas << 2) | 3;
fine = 0;
if (find_strobes_low(channel_offset, &mediumcoarse, &fine, sysinfo))
return -1;
if (find_strobes_edge(channel_offset, &mediumcoarse, &fine, sysinfo))
return -1;
if (add_quarter_clock(channel_offset, &mediumcoarse, &fine))
return -1;
if (find_preamble(channel_offset, &mediumcoarse, sysinfo))
return -1;
if (add_quarter_clock(channel_offset, &mediumcoarse, &fine))
return -1;
if (normalize(channel_offset, &mediumcoarse, &fine))
return -1;
/* This is a debug check to see if the rcven code is fully working.
* It can be removed when the output message is not printed anymore
*/
if (MCHBAR8(C0WL0REOST + channel_offset) == 0)
printk(BIOS_DEBUG, "Weird. No C%sWL0REOST\n", channel_offset?"1":"0");
return 0;
}
void receive_enable_adjust(struct sys_info *sysinfo)
{
/* Is channel 0 populated? */
if (sysinfo->dimm[0] != SYSINFO_DIMM_NOT_POPULATED
|| sysinfo->dimm[1] != SYSINFO_DIMM_NOT_POPULATED)
if (receive_enable_autoconfig(0, sysinfo))
return;
/* Is channel 1 populated? */
if (sysinfo->dimm[2] != SYSINFO_DIMM_NOT_POPULATED
|| sysinfo->dimm[3] != SYSINFO_DIMM_NOT_POPULATED)
if (receive_enable_autoconfig(0x80, sysinfo))
return;
}
|
