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Commit | Line | Data |
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121915c4 WB |
1 | /* |
2 | * BCM947xx nvram variable access | |
3 | * | |
4 | * Copyright (C) 2005 Broadcom Corporation | |
5 | * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org> | |
f36738dd | 6 | * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de> |
121915c4 | 7 | * |
70342287 RB |
8 | * This program is free software; you can redistribute it and/or modify it |
9 | * under the terms of the GNU General Public License as published by the | |
121915c4 WB |
10 | * Free Software Foundation; either version 2 of the License, or (at your |
11 | * option) any later version. | |
12 | */ | |
13 | ||
50c97910 | 14 | #include <linux/io.h> |
121915c4 WB |
15 | #include <linux/types.h> |
16 | #include <linux/module.h> | |
121915c4 WB |
17 | #include <linux/kernel.h> |
18 | #include <linux/string.h> | |
9d1d0864 | 19 | #include <linux/mtd/mtd.h> |
138173d4 | 20 | #include <linux/bcm47xx_nvram.h> |
121915c4 | 21 | |
d548ca6b | 22 | #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */ |
6ab7c290 | 23 | #define NVRAM_SPACE 0x10000 |
d548ca6b RM |
24 | #define NVRAM_MAX_GPIO_ENTRIES 32 |
25 | #define NVRAM_MAX_GPIO_VALUE_LEN 30 | |
341097f1 RM |
26 | |
27 | #define FLASH_MIN 0x00020000 /* Minimum flash size */ | |
28 | ||
29 | struct nvram_header { | |
30 | u32 magic; | |
31 | u32 len; | |
32 | u32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */ | |
33 | u32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */ | |
34 | u32 config_ncdl; /* ncdl values for memc */ | |
35 | }; | |
36 | ||
121915c4 | 37 | static char nvram_buf[NVRAM_SPACE]; |
94a0535b | 38 | static size_t nvram_len; |
f4c4d589 | 39 | static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000}; |
121915c4 | 40 | |
8d602dd0 | 41 | static u32 find_nvram_size(void __iomem *end) |
f36738dd | 42 | { |
8d602dd0 | 43 | struct nvram_header __iomem *header; |
f36738dd HM |
44 | int i; |
45 | ||
46 | for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) { | |
8d602dd0 | 47 | header = (struct nvram_header *)(end - nvram_sizes[i]); |
341097f1 | 48 | if (header->magic == NVRAM_MAGIC) |
f36738dd HM |
49 | return nvram_sizes[i]; |
50 | } | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
121915c4 | 55 | /* Probe for NVRAM header */ |
8d602dd0 | 56 | static int nvram_find_and_copy(void __iomem *iobase, u32 lim) |
121915c4 | 57 | { |
8d602dd0 | 58 | struct nvram_header __iomem *header; |
121915c4 | 59 | int i; |
08ccf572 | 60 | u32 off; |
121915c4 | 61 | u32 *src, *dst; |
f36738dd | 62 | u32 size; |
121915c4 | 63 | |
94a0535b | 64 | if (nvram_len) { |
8d602dd0 RM |
65 | pr_warn("nvram already initialized\n"); |
66 | return -EEXIST; | |
67 | } | |
68 | ||
c4485671 | 69 | /* TODO: when nvram is on nand flash check for bad blocks first. */ |
121915c4 WB |
70 | off = FLASH_MIN; |
71 | while (off <= lim) { | |
72 | /* Windowed flash access */ | |
8d602dd0 | 73 | size = find_nvram_size(iobase + off); |
f36738dd | 74 | if (size) { |
8d602dd0 | 75 | header = (struct nvram_header *)(iobase + off - size); |
121915c4 | 76 | goto found; |
f36738dd | 77 | } |
121915c4 WB |
78 | off <<= 1; |
79 | } | |
80 | ||
81 | /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */ | |
8d602dd0 | 82 | header = (struct nvram_header *)(iobase + 4096); |
341097f1 | 83 | if (header->magic == NVRAM_MAGIC) { |
f36738dd | 84 | size = NVRAM_SPACE; |
121915c4 | 85 | goto found; |
f36738dd | 86 | } |
121915c4 | 87 | |
8d602dd0 | 88 | header = (struct nvram_header *)(iobase + 1024); |
341097f1 | 89 | if (header->magic == NVRAM_MAGIC) { |
f36738dd | 90 | size = NVRAM_SPACE; |
121915c4 | 91 | goto found; |
f36738dd | 92 | } |
121915c4 | 93 | |
f36738dd | 94 | pr_err("no nvram found\n"); |
cc4403e0 | 95 | return -ENXIO; |
121915c4 WB |
96 | |
97 | found: | |
d548ca6b RM |
98 | src = (u32 *)header; |
99 | dst = (u32 *)nvram_buf; | |
121915c4 | 100 | for (i = 0; i < sizeof(struct nvram_header); i += 4) |
23d2bc42 | 101 | *dst++ = __raw_readl(src++); |
55cab93b | 102 | header = (struct nvram_header *)nvram_buf; |
94a0535b RM |
103 | nvram_len = header->len; |
104 | if (nvram_len > size) { | |
55cab93b | 105 | pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n"); |
94a0535b | 106 | nvram_len = size; |
55cab93b | 107 | } |
94a0535b | 108 | if (nvram_len >= NVRAM_SPACE) { |
55cab93b HM |
109 | pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", |
110 | header->len, NVRAM_SPACE - 1); | |
94a0535b | 111 | nvram_len = NVRAM_SPACE - 1; |
55cab93b HM |
112 | } |
113 | /* proceed reading data after header */ | |
94a0535b | 114 | for (; i < nvram_len; i += 4) |
23d2bc42 | 115 | *dst++ = readl(src++); |
d28c9a55 | 116 | nvram_buf[NVRAM_SPACE - 1] = '\0'; |
cc4403e0 HM |
117 | |
118 | return 0; | |
121915c4 WB |
119 | } |
120 | ||
21400f25 RM |
121 | /* |
122 | * On bcm47xx we need access to the NVRAM very early, so we can't use mtd | |
123 | * subsystem to access flash. We can't even use platform device / driver to | |
124 | * store memory offset. | |
125 | * To handle this we provide following symbol. It's supposed to be called as | |
126 | * soon as we get info about flash device, before any NVRAM entry is needed. | |
127 | */ | |
128 | int bcm47xx_nvram_init_from_mem(u32 base, u32 lim) | |
8d602dd0 RM |
129 | { |
130 | void __iomem *iobase; | |
131 | int err; | |
132 | ||
133 | iobase = ioremap_nocache(base, lim); | |
134 | if (!iobase) | |
135 | return -ENOMEM; | |
136 | ||
137 | err = nvram_find_and_copy(iobase, lim); | |
138 | ||
139 | iounmap(iobase); | |
140 | ||
141 | return err; | |
142 | } | |
143 | ||
e58da16f | 144 | static int nvram_init(void) |
bb765632 | 145 | { |
9d1d0864 RM |
146 | #ifdef CONFIG_MTD |
147 | struct mtd_info *mtd; | |
148 | struct nvram_header header; | |
149 | size_t bytes_read; | |
40d12172 | 150 | int err; |
9d1d0864 RM |
151 | |
152 | mtd = get_mtd_device_nm("nvram"); | |
153 | if (IS_ERR(mtd)) | |
154 | return -ENODEV; | |
155 | ||
40d12172 | 156 | err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header); |
55cab93b HM |
157 | if (!err && header.magic == NVRAM_MAGIC && |
158 | header.len > sizeof(header)) { | |
94a0535b RM |
159 | nvram_len = header.len; |
160 | if (nvram_len >= NVRAM_SPACE) { | |
40d12172 | 161 | pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", |
55cab93b | 162 | header.len, NVRAM_SPACE); |
94a0535b | 163 | nvram_len = NVRAM_SPACE - 1; |
40d12172 | 164 | } |
9d1d0864 | 165 | |
94a0535b | 166 | err = mtd_read(mtd, 0, nvram_len, &nvram_len, |
55cab93b | 167 | (u8 *)nvram_buf); |
94a0535b | 168 | return err; |
9d1d0864 RM |
169 | } |
170 | #endif | |
7177efc5 | 171 | |
cc4403e0 | 172 | return -ENXIO; |
bb765632 RM |
173 | } |
174 | ||
341097f1 | 175 | int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len) |
121915c4 WB |
176 | { |
177 | char *var, *value, *end, *eq; | |
5bfad4ee | 178 | int err; |
121915c4 WB |
179 | |
180 | if (!name) | |
ee7e2f3c | 181 | return -EINVAL; |
121915c4 | 182 | |
94a0535b | 183 | if (!nvram_len) { |
e58da16f | 184 | err = nvram_init(); |
cc4403e0 HM |
185 | if (err) |
186 | return err; | |
187 | } | |
121915c4 WB |
188 | |
189 | /* Look for name=value and return value */ | |
190 | var = &nvram_buf[sizeof(struct nvram_header)]; | |
5bfad4ee RM |
191 | end = nvram_buf + sizeof(nvram_buf); |
192 | while (var < end && *var) { | |
193 | eq = strchr(var, '='); | |
121915c4 WB |
194 | if (!eq) |
195 | break; | |
196 | value = eq + 1; | |
d548ca6b RM |
197 | if (eq - var == strlen(name) && |
198 | strncmp(var, name, eq - var) == 0) | |
44d4b2ae | 199 | return snprintf(val, val_len, "%s", value); |
5bfad4ee | 200 | var = value + strlen(value) + 1; |
50c97910 | 201 | } |
ee7e2f3c | 202 | return -ENOENT; |
121915c4 | 203 | } |
111bd981 | 204 | EXPORT_SYMBOL(bcm47xx_nvram_getenv); |
62cf3bc0 HM |
205 | |
206 | int bcm47xx_nvram_gpio_pin(const char *name) | |
207 | { | |
208 | int i, err; | |
d548ca6b RM |
209 | char nvram_var[] = "gpioXX"; |
210 | char buf[NVRAM_MAX_GPIO_VALUE_LEN]; | |
62cf3bc0 | 211 | |
d548ca6b RM |
212 | /* TODO: Optimize it to don't call getenv so many times */ |
213 | for (i = 0; i < NVRAM_MAX_GPIO_ENTRIES; i++) { | |
62cf3bc0 HM |
214 | err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i); |
215 | if (err <= 0) | |
216 | continue; | |
217 | err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf)); | |
218 | if (err <= 0) | |
219 | continue; | |
220 | if (!strcmp(name, buf)) | |
221 | return i; | |
222 | } | |
223 | return -ENOENT; | |
224 | } | |
225 | EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin); | |
55cab93b HM |
226 | |
227 | char *bcm47xx_nvram_get_contents(size_t *nvram_size) | |
228 | { | |
229 | int err; | |
230 | char *nvram; | |
55cab93b | 231 | |
94a0535b | 232 | if (!nvram_len) { |
55cab93b HM |
233 | err = nvram_init(); |
234 | if (err) | |
235 | return NULL; | |
236 | } | |
237 | ||
94a0535b | 238 | *nvram_size = nvram_len - sizeof(struct nvram_header); |
55cab93b HM |
239 | nvram = vmalloc(*nvram_size); |
240 | if (!nvram) | |
241 | return NULL; | |
242 | memcpy(nvram, &nvram_buf[sizeof(struct nvram_header)], *nvram_size); | |
243 | ||
244 | return nvram; | |
245 | } | |
246 | EXPORT_SYMBOL(bcm47xx_nvram_get_contents); | |
f6e734a8 | 247 | |
72ccc89e | 248 | MODULE_LICENSE("GPL v2"); |