arch/mips/bcm63xx/nvram.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7  * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
   8  * Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
   9  */
  10
  11 #define pr_fmt(fmt) "bcm63xx_nvram: " fmt
  12
  13 #include <linux/bcm963xx_nvram.h>
  14 #include <linux/init.h>
  15 #include <linux/crc32.h>
  16 #include <linux/export.h>
  17 #include <linux/kernel.h>
  18 #include <linux/if_ether.h>
  19
  20 #include <bcm63xx_nvram.h>
  21
  22 static struct bcm963xx_nvram nvram;
  23 static int mac_addr_used;
  24
  25 void __init bcm63xx_nvram_init(void *addr)
  26 {
  27         u32 crc, expected_crc;
  28         u8 hcs_mac_addr[ETH_ALEN] = { 0x00, 0x10, 0x18, 0xff, 0xff, 0xff };
  29
  30         /* extract nvram data */
  31         memcpy(&nvram, addr, BCM963XX_NVRAM_V5_SIZE);
  32
  33         /* check checksum before using data */
  34         if (bcm963xx_nvram_checksum(&nvram, &expected_crc, &crc))
  35                 pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  36                         expected_crc, crc);
  37
  38         /* Cable modems have a different NVRAM which is embedded in the eCos
  39          * firmware and not easily extractible, give at least a MAC address
  40          * pool.
  41          */
  42         if (BCMCPU_IS_3368()) {
  43                 memcpy(nvram.mac_addr_base, hcs_mac_addr, ETH_ALEN);
  44                 nvram.mac_addr_count = 2;
  45         }
  46 }
  47
  48 u8 *bcm63xx_nvram_get_name(void)
  49 {
  50         return nvram.name;
  51 }
  52 EXPORT_SYMBOL(bcm63xx_nvram_get_name);
  53
  54 int bcm63xx_nvram_get_mac_address(u8 *mac)
  55 {
  56         u8 *oui;
  57         int count;
  58
  59         if (mac_addr_used >= nvram.mac_addr_count) {
  60                 pr_err("not enough mac addresses\n");
  61                 return -ENODEV;
  62         }
  63
  64         memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
  65         oui = mac + ETH_ALEN/2 - 1;
  66         count = mac_addr_used;
  67
  68         while (count--) {
  69                 u8 *p = mac + ETH_ALEN - 1;
  70
  71                 do {
  72                         (*p)++;
  73                         if (*p != 0)
  74                                 break;
  75                         p--;
  76                 } while (p != oui);
  77
  78                 if (p == oui) {
  79                         pr_err("unable to fetch mac address\n");
  80                         return -ENODEV;
  81                 }
  82         }
  83
  84         mac_addr_used++;
  85         return 0;
  86 }
  87 EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);