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) 2010-2011 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/init.h>
15 #include <linux/types.h>
16 #include <linux/module.h>
17 #include <linux/ssb/ssb.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <asm/addrspace.h>
21 #include <asm/mach-bcm47xx/nvram.h>
22 #include <asm/mach-bcm47xx/bcm47xx.h>
23
24 static char nvram_buf[NVRAM_SPACE];
25
26 /* Probe for NVRAM header */
early_nvram_init(void)27 static void early_nvram_init(void)
28 {
29 #ifdef CONFIG_BCM47XX_SSB
30 struct ssb_mipscore *mcore_ssb;
31 #endif
32 #ifdef CONFIG_BCM47XX_BCMA
33 struct bcma_drv_cc *bcma_cc;
34 #endif
35 struct nvram_header *header;
36 int i;
37 u32 base = 0;
38 u32 lim = 0;
39 u32 off;
40 u32 *src, *dst;
41
42 switch (bcm47xx_bus_type) {
43 #ifdef CONFIG_BCM47XX_SSB
44 case BCM47XX_BUS_TYPE_SSB:
45 mcore_ssb = &bcm47xx_bus.ssb.mipscore;
46 base = mcore_ssb->flash_window;
47 lim = mcore_ssb->flash_window_size;
48 break;
49 #endif
50 #ifdef CONFIG_BCM47XX_BCMA
51 case BCM47XX_BUS_TYPE_BCMA:
52 bcma_cc = &bcm47xx_bus.bcma.bus.drv_cc;
53 base = bcma_cc->pflash.window;
54 lim = bcma_cc->pflash.window_size;
55 break;
56 #endif
57 }
58
59 off = FLASH_MIN;
60 while (off <= lim) {
61 /* Windowed flash access */
62 header = (struct nvram_header *)
63 KSEG1ADDR(base + off - NVRAM_SPACE);
64 if (header->magic == NVRAM_HEADER)
65 goto found;
66 off <<= 1;
67 }
68
69 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
70 header = (struct nvram_header *) KSEG1ADDR(base + 4096);
71 if (header->magic == NVRAM_HEADER)
72 goto found;
73
74 header = (struct nvram_header *) KSEG1ADDR(base + 1024);
75 if (header->magic == NVRAM_HEADER)
76 goto found;
77
78 return;
79
80 found:
81 src = (u32 *) header;
82 dst = (u32 *) nvram_buf;
83 for (i = 0; i < sizeof(struct nvram_header); i += 4)
84 *dst++ = *src++;
85 for (; i < header->len && i < NVRAM_SPACE; i += 4)
86 *dst++ = le32_to_cpu(*src++);
87 }
88
nvram_getenv(char * name,char * val,size_t val_len)89 int nvram_getenv(char *name, char *val, size_t val_len)
90 {
91 char *var, *value, *end, *eq;
92
93 if (!name)
94 return NVRAM_ERR_INV_PARAM;
95
96 if (!nvram_buf[0])
97 early_nvram_init();
98
99 /* Look for name=value and return value */
100 var = &nvram_buf[sizeof(struct nvram_header)];
101 end = nvram_buf + sizeof(nvram_buf) - 2;
102 end[0] = end[1] = '\0';
103 for (; *var; var = value + strlen(value) + 1) {
104 eq = strchr(var, '=');
105 if (!eq)
106 break;
107 value = eq + 1;
108 if ((eq - var) == strlen(name) &&
109 strncmp(var, name, (eq - var)) == 0) {
110 snprintf(val, val_len, "%s", value);
111 return 0;
112 }
113 }
114 return NVRAM_ERR_ENVNOTFOUND;
115 }
116 EXPORT_SYMBOL(nvram_getenv);
117