| 1 | /* |
| 2 | * BCM947xx nvram variable access |
| 3 | * |
| 4 | * Copyright 2005, Broadcom Corporation |
| 5 | * Copyright 2006, Felix Fietkau <nbd@openwrt.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms of the GNU General Public License as published by the |
| 9 | * Free Software Foundation; either version 2 of the License, or (at your |
| 10 | * option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/init.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/ssb/ssb.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <asm/byteorder.h> |
| 22 | #include <asm/bootinfo.h> |
| 23 | #include <asm/addrspace.h> |
| 24 | #include <asm/io.h> |
| 25 | #include <asm/uaccess.h> |
| 26 | |
| 27 | #include <nvram.h> |
| 28 | |
| 29 | #define MB * 1048576 |
| 30 | extern struct ssb_bus ssb; |
| 31 | |
| 32 | static char nvram_buf[NVRAM_SPACE]; |
| 33 | static int cfe_env; |
| 34 | extern char *cfe_env_get(char *nv_buf, const char *name); |
| 35 | |
| 36 | /* Probe for NVRAM header */ |
| 37 | static void __init early_nvram_init(void) |
| 38 | { |
| 39 | struct ssb_mipscore *mcore = &ssb.mipscore; |
| 40 | struct nvram_header *header; |
| 41 | int i; |
| 42 | u32 base, lim, off; |
| 43 | u32 *src, *dst; |
| 44 | |
| 45 | base = mcore->flash_window; |
| 46 | lim = mcore->flash_window_size; |
| 47 | cfe_env = 0; |
| 48 | |
| 49 | |
| 50 | /* XXX: hack for supporting the CFE environment stuff on WGT634U */ |
| 51 | if (lim >= 8 MB) { |
| 52 | src = (u32 *) KSEG1ADDR(base + 8 MB - 0x2000); |
| 53 | dst = (u32 *) nvram_buf; |
| 54 | |
| 55 | if ((*src & 0xff00ff) == 0x000001) { |
| 56 | printk("early_nvram_init: WGT634U NVRAM found.\n"); |
| 57 | |
| 58 | for (i = 0; i < 0x1ff0; i++) { |
| 59 | if (*src == 0xFFFFFFFF) |
| 60 | break; |
| 61 | *dst++ = *src++; |
| 62 | } |
| 63 | cfe_env = 1; |
| 64 | return; |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | off = 0x20000; |
| 69 | while (off <= lim) { |
| 70 | /* Windowed flash access */ |
| 71 | header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE); |
| 72 | if (header->magic == NVRAM_HEADER) |
| 73 | goto found; |
| 74 | off <<= 1; |
| 75 | } |
| 76 | |
| 77 | /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */ |
| 78 | header = (struct nvram_header *) KSEG1ADDR(base + 4096); |
| 79 | if (header->magic == NVRAM_HEADER) |
| 80 | goto found; |
| 81 | |
| 82 | header = (struct nvram_header *) KSEG1ADDR(base + 1024); |
| 83 | if (header->magic == NVRAM_HEADER) |
| 84 | goto found; |
| 85 | |
| 86 | return; |
| 87 | |
| 88 | found: |
| 89 | src = (u32 *) header; |
| 90 | dst = (u32 *) nvram_buf; |
| 91 | for (i = 0; i < sizeof(struct nvram_header); i += 4) |
| 92 | *dst++ = *src++; |
| 93 | for (; i < header->len && i < NVRAM_SPACE; i += 4) |
| 94 | *dst++ = le32_to_cpu(*src++); |
| 95 | } |
| 96 | |
| 97 | char *nvram_get(const char *name) |
| 98 | { |
| 99 | char *var, *value, *end, *eq; |
| 100 | |
| 101 | if (!name) |
| 102 | return NULL; |
| 103 | |
| 104 | if (!nvram_buf[0]) |
| 105 | early_nvram_init(); |
| 106 | |
| 107 | if (cfe_env) |
| 108 | return cfe_env_get(nvram_buf, name); |
| 109 | |
| 110 | /* Look for name=value and return value */ |
| 111 | var = &nvram_buf[sizeof(struct nvram_header)]; |
| 112 | end = nvram_buf + sizeof(nvram_buf) - 2; |
| 113 | end[0] = end[1] = '\0'; |
| 114 | for (; *var; var = value + strlen(value) + 1) { |
| 115 | if (!(eq = strchr(var, '='))) |
| 116 | break; |
| 117 | value = eq + 1; |
| 118 | if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0) |
| 119 | return value; |
| 120 | } |
| 121 | |
| 122 | return NULL; |
| 123 | } |
| 124 | |
| 125 | EXPORT_SYMBOL(nvram_get); |
| 126 | |
