target/linux/easygate-2.6/files/arch/mips/bcm963xx/nvram.c

   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/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/slab.h>
  20 #include <asm/byteorder.h>
  21 #include <asm/bootinfo.h>
  22 #include <asm/addrspace.h>
  23 #include <asm/io.h>
  24 #include <asm/uaccess.h>
  25
  26 #include <nvram.h>
  27
  28 #define MB * 1048576
  29
  30 #define WINDOW_ADDR     0x1F000000
  31 #define WINDOW_SIZE     0x800000
  32
  33 static char nvram_buf[NVRAM_SPACE];
  34 static int cfe_env;
  35 extern char *cfe_env_get(char *nv_buf, const char *name);
  36
  37 /* Probe for NVRAM header */
  38 void __init early_nvram_init(void)
  39 {
  40         struct nvram_header *header;
  41         int i;
  42         u32 base, lim, off;
  43         u32 *src, *dst;
  44
  45         base = WINDOW_ADDR;
  46         lim = 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 - 0x20000);
  53                 dst = (u32 *) nvram_buf;
  54
  55                 /* We are looking for the String gOGoBrCm */
  56                 if ((*src) == 0x674f476f && (*(src + 1)) == 0x4272436d) {
  57                         printk("early_nvram_init: EasyGate NVRAM found.\n");
  58
  59                         for (i = 0; i < 0x1ff0; i++) {
  60                                 if (*src == 0xFFFFFFFF)
  61                                         break;
  62                                 *dst++ = *src++;
  63                         }
  64                         cfe_env = 1;
  65                         return;
  66                 }
  67         }
  68
  69         off = 0x20000;
  70         while (off <= lim) {
  71                 /* Windowed flash access */
  72                 header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
  73                 if (header->magic == NVRAM_HEADER)
  74                         goto found;
  75                 off <<= 1;
  76         }
  77
  78         /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
  79         header = (struct nvram_header *) KSEG1ADDR(base + 4096);
  80         if (header->magic == NVRAM_HEADER)
  81                 goto found;
  82
  83         header = (struct nvram_header *) KSEG1ADDR(base + 1024);
  84         if (header->magic == NVRAM_HEADER)
  85                 goto found;
  86
  87         printk("Found no CFE environnment\n");
  88         return;
  89
  90 found:
  91         printk("Found CFE environnment\n");
  92         src = (u32 *) header;
  93         dst = (u32 *) nvram_buf;
  94         for (i = 0; i < sizeof(struct nvram_header); i += 4)
  95                 *dst++ = *src++;
  96         for (; i < header->len && i < NVRAM_SPACE; i += 4)
  97                 //*dst++ = le32_to_cpu(*src++);
  98                 *dst++ = be32_to_cpu(*src++);
  99 }
 100
 101 char *nvram_get(const char *name)
 102 {
 103         char *var, *value, *end, *eq;
 104
 105         if (!name)
 106                 return NULL;
 107
 108         if (!nvram_buf[0])
 109                 early_nvram_init();
 110
 111         if (cfe_env)
 112                 return cfe_env_get(nvram_buf, name);
 113
 114         /* Look for name=value and return value */
 115         var = &nvram_buf[sizeof(struct nvram_header)];
 116         end = nvram_buf + sizeof(nvram_buf) - 2;
 117         end[0] = end[1] = '\0';
 118         for (; *var; var = value + strlen(value) + 1) {
 119                 if (!(eq = strchr(var, '=')))
 120                         break;
 121                 value = eq + 1;
 122                 if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
 123                         return value;
 124         }
 125
 126         return NULL;
 127 }
 128
 129 EXPORT_SYMBOL(nvram_get);