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
|
/*
* BCM947xx nvram variable access
*
* Copyright (C) 2005 Broadcom Corporation
* Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
*
* 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.
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mtd/mtd.h>
#include <bcm47xx_nvram.h>
#define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
#define NVRAM_SPACE 0x8000
#define FLASH_MIN 0x00020000 /* Minimum flash size */
struct nvram_header {
u32 magic;
u32 len;
u32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
u32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
u32 config_ncdl; /* ncdl values for memc */
};
static char nvram_buf[NVRAM_SPACE];
static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
static u32 find_nvram_size(void __iomem *end)
{
struct nvram_header __iomem *header;
int i;
for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
header = (struct nvram_header *)(end - nvram_sizes[i]);
if (header->magic == NVRAM_MAGIC)
return nvram_sizes[i];
}
return 0;
}
/* Probe for NVRAM header */
static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
{
struct nvram_header __iomem *header;
int i;
u32 off;
u32 *src, *dst;
u32 size;
if (nvram_buf[0]) {
pr_warn("nvram already initialized\n");
return -EEXIST;
}
/* TODO: when nvram is on nand flash check for bad blocks first. */
off = FLASH_MIN;
while (off <= lim) {
/* Windowed flash access */
size = find_nvram_size(iobase + off);
if (size) {
header = (struct nvram_header *)(iobase + off - size);
goto found;
}
off <<= 1;
}
/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
header = (struct nvram_header *)(iobase + 4096);
if (header->magic == NVRAM_MAGIC) {
size = NVRAM_SPACE;
goto found;
}
header = (struct nvram_header *)(iobase + 1024);
if (header->magic == NVRAM_MAGIC) {
size = NVRAM_SPACE;
goto found;
}
pr_err("no nvram found\n");
return -ENXIO;
found:
if (header->len > size)
pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n");
if (header->len > NVRAM_SPACE)
pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
header->len, NVRAM_SPACE);
src = (u32 *) header;
dst = (u32 *) nvram_buf;
for (i = 0; i < sizeof(struct nvram_header); i += 4)
*dst++ = *src++;
for (; i < header->len && i < NVRAM_SPACE && i < size; i += 4)
*dst++ = le32_to_cpu(*src++);
memset(dst, 0x0, NVRAM_SPACE - i);
return 0;
}
/*
* On bcm47xx we need access to the NVRAM very early, so we can't use mtd
* subsystem to access flash. We can't even use platform device / driver to
* store memory offset.
* To handle this we provide following symbol. It's supposed to be called as
* soon as we get info about flash device, before any NVRAM entry is needed.
*/
int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)
{
void __iomem *iobase;
int err;
iobase = ioremap_nocache(base, lim);
if (!iobase)
return -ENOMEM;
err = nvram_find_and_copy(iobase, lim);
iounmap(iobase);
return err;
}
static int nvram_init(void)
{
#ifdef CONFIG_MTD
struct mtd_info *mtd;
struct nvram_header header;
size_t bytes_read;
int err, i;
mtd = get_mtd_device_nm("nvram");
if (IS_ERR(mtd))
return -ENODEV;
for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
loff_t from = mtd->size - nvram_sizes[i];
if (from < 0)
continue;
err = mtd_read(mtd, from, sizeof(header), &bytes_read,
(uint8_t *)&header);
if (!err && header.magic == NVRAM_MAGIC) {
u8 *dst = (uint8_t *)nvram_buf;
size_t len = header.len;
if (header.len > NVRAM_SPACE) {
pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
header.len, NVRAM_SPACE);
len = NVRAM_SPACE;
}
err = mtd_read(mtd, from, len, &bytes_read, dst);
if (err)
return err;
memset(dst + bytes_read, 0x0, NVRAM_SPACE - bytes_read);
return 0;
}
}
#endif
return -ENXIO;
}
int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len)
{
char *var, *value, *end, *eq;
int err;
if (!name)
return -EINVAL;
if (!nvram_buf[0]) {
err = nvram_init();
if (err)
return err;
}
/* Look for name=value and return value */
var = &nvram_buf[sizeof(struct nvram_header)];
end = nvram_buf + sizeof(nvram_buf) - 2;
end[0] = end[1] = '\0';
for (; *var; var = value + strlen(value) + 1) {
eq = strchr(var, '=');
if (!eq)
break;
value = eq + 1;
if ((eq - var) == strlen(name) &&
strncmp(var, name, (eq - var)) == 0) {
return snprintf(val, val_len, "%s", value);
}
}
return -ENOENT;
}
EXPORT_SYMBOL(bcm47xx_nvram_getenv);
int bcm47xx_nvram_gpio_pin(const char *name)
{
int i, err;
char nvram_var[10];
char buf[30];
for (i = 0; i < 32; i++) {
err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
if (err <= 0)
continue;
err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
if (err <= 0)
continue;
if (!strcmp(name, buf))
return i;
}
return -ENOENT;
}
EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);
|
