arch/mips/bcm47xx/nvram.c

   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
  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 */
  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
  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
 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
 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
 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
 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);