1 /*
2 * BCM947xx nvram variable access
3 *
4 * Copyright (C) 2005 Broadcom Corporation
5 * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
6 * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
7 *
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
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14 #include <linux/types.h>
15 #include <linux/module.h>
16 #include <linux/ssb/ssb.h>
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <asm/addrspace.h>
20 #include <bcm47xx_nvram.h>
21 #include <asm/mach-bcm47xx/bcm47xx.h>
22
23 static char nvram_buf[NVRAM_SPACE];
24 static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
25
find_nvram_size(u32 end)26 static u32 find_nvram_size(u32 end)
27 {
28 struct nvram_header *header;
29 int i;
30
31 for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
32 header = (struct nvram_header *)KSEG1ADDR(end - nvram_sizes[i]);
33 if (header->magic == NVRAM_HEADER)
34 return nvram_sizes[i];
35 }
36
37 return 0;
38 }
39
40 /* Probe for NVRAM header */
nvram_find_and_copy(u32 base,u32 lim)41 static int nvram_find_and_copy(u32 base, u32 lim)
42 {
43 struct nvram_header *header;
44 int i;
45 u32 off;
46 u32 *src, *dst;
47 u32 size;
48
49 /* TODO: when nvram is on nand flash check for bad blocks first. */
50 off = FLASH_MIN;
51 while (off <= lim) {
52 /* Windowed flash access */
53 size = find_nvram_size(base + off);
54 if (size) {
55 header = (struct nvram_header *)KSEG1ADDR(base + off -
56 size);
57 goto found;
58 }
59 off <<= 1;
60 }
61
62 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
63 header = (struct nvram_header *) KSEG1ADDR(base + 4096);
64 if (header->magic == NVRAM_HEADER) {
65 size = NVRAM_SPACE;
66 goto found;
67 }
68
69 header = (struct nvram_header *) KSEG1ADDR(base + 1024);
70 if (header->magic == NVRAM_HEADER) {
71 size = NVRAM_SPACE;
72 goto found;
73 }
74
75 pr_err("no nvram found\n");
76 return -ENXIO;
77
78 found:
79
80 if (header->len > size)
81 pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n");
82 if (header->len > NVRAM_SPACE)
83 pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
84 header->len, NVRAM_SPACE);
85
86 src = (u32 *) header;
87 dst = (u32 *) nvram_buf;
88 for (i = 0; i < sizeof(struct nvram_header); i += 4)
89 *dst++ = *src++;
90 for (; i < header->len && i < NVRAM_SPACE && i < size; i += 4)
91 *dst++ = le32_to_cpu(*src++);
92 memset(dst, 0x0, NVRAM_SPACE - i);
93
94 return 0;
95 }
96
97 #ifdef CONFIG_BCM47XX_SSB
nvram_init_ssb(void)98 static int nvram_init_ssb(void)
99 {
100 struct ssb_mipscore *mcore = &bcm47xx_bus.ssb.mipscore;
101 u32 base;
102 u32 lim;
103
104 if (mcore->pflash.present) {
105 base = mcore->pflash.window;
106 lim = mcore->pflash.window_size;
107 } else {
108 pr_err("Couldn't find supported flash memory\n");
109 return -ENXIO;
110 }
111
112 return nvram_find_and_copy(base, lim);
113 }
114 #endif
115
116 #ifdef CONFIG_BCM47XX_BCMA
nvram_init_bcma(void)117 static int nvram_init_bcma(void)
118 {
119 struct bcma_drv_cc *cc = &bcm47xx_bus.bcma.bus.drv_cc;
120 u32 base;
121 u32 lim;
122
123 #ifdef CONFIG_BCMA_NFLASH
124 if (cc->nflash.boot) {
125 base = BCMA_SOC_FLASH1;
126 lim = BCMA_SOC_FLASH1_SZ;
127 } else
128 #endif
129 if (cc->pflash.present) {
130 base = cc->pflash.window;
131 lim = cc->pflash.window_size;
132 #ifdef CONFIG_BCMA_SFLASH
133 } else if (cc->sflash.present) {
134 base = cc->sflash.window;
135 lim = cc->sflash.size;
136 #endif
137 } else {
138 pr_err("Couldn't find supported flash memory\n");
139 return -ENXIO;
140 }
141
142 return nvram_find_and_copy(base, lim);
143 }
144 #endif
145
nvram_init(void)146 static int nvram_init(void)
147 {
148 switch (bcm47xx_bus_type) {
149 #ifdef CONFIG_BCM47XX_SSB
150 case BCM47XX_BUS_TYPE_SSB:
151 return nvram_init_ssb();
152 #endif
153 #ifdef CONFIG_BCM47XX_BCMA
154 case BCM47XX_BUS_TYPE_BCMA:
155 return nvram_init_bcma();
156 #endif
157 }
158 return -ENXIO;
159 }
160
bcm47xx_nvram_getenv(char * name,char * val,size_t val_len)161 int bcm47xx_nvram_getenv(char *name, char *val, size_t val_len)
162 {
163 char *var, *value, *end, *eq;
164 int err;
165
166 if (!name)
167 return -EINVAL;
168
169 if (!nvram_buf[0]) {
170 err = nvram_init();
171 if (err)
172 return err;
173 }
174
175 /* Look for name=value and return value */
176 var = &nvram_buf[sizeof(struct nvram_header)];
177 end = nvram_buf + sizeof(nvram_buf) - 2;
178 end[0] = end[1] = '\0';
179 for (; *var; var = value + strlen(value) + 1) {
180 eq = strchr(var, '=');
181 if (!eq)
182 break;
183 value = eq + 1;
184 if ((eq - var) == strlen(name) &&
185 strncmp(var, name, (eq - var)) == 0) {
186 return snprintf(val, val_len, "%s", value);
187 }
188 }
189 return -ENOENT;
190 }
191 EXPORT_SYMBOL(bcm47xx_nvram_getenv);
192
bcm47xx_nvram_gpio_pin(const char * name)193 int bcm47xx_nvram_gpio_pin(const char *name)
194 {
195 int i, err;
196 char nvram_var[10];
197 char buf[30];
198
199 for (i = 0; i < 32; i++) {
200 err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
201 if (err <= 0)
202 continue;
203 err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
204 if (err <= 0)
205 continue;
206 if (!strcmp(name, buf))
207 return i;
208 }
209 return -ENOENT;
210 }
211 EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);
212