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 #define BCM63XX_DEFAULT_PSI_SIZE        64
  23
  24 static struct bcm963xx_nvram nvram;
  25 static int mac_addr_used;
  26
  27 void __init bcm63xx_nvram_init(void *addr)
  28 {
  29         u32 crc, expected_crc;
  30         u8 hcs_mac_addr[ETH_ALEN] = { 0x00, 0x10, 0x18, 0xff, 0xff, 0xff };
  31
  32         /* extract nvram data */
  33         memcpy(&nvram, addr, BCM963XX_NVRAM_V5_SIZE);
  34
  35         /* check checksum before using data */
  36         if (bcm963xx_nvram_checksum(&nvram, &expected_crc, &crc))
  37                 pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  38                         expected_crc, crc);
  39
  40         /* Cable modems have a different NVRAM which is embedded in the eCos
  41          * firmware and not easily extractible, give at least a MAC address
  42          * pool.
  43          */
  44         if (BCMCPU_IS_3368()) {
  45                 memcpy(nvram.mac_addr_base, hcs_mac_addr, ETH_ALEN);
  46                 nvram.mac_addr_count = 2;
  47         }
  48 }
  49
  50 u8 *bcm63xx_nvram_get_name(void)
  51 {
  52         return nvram.name;
  53 }
  54 EXPORT_SYMBOL(bcm63xx_nvram_get_name);
  55
  56 int bcm63xx_nvram_get_mac_address(u8 *mac)
  57 {
  58         u8 *oui;
  59         int count;
  60
  61         if (mac_addr_used >= nvram.mac_addr_count) {
  62                 pr_err("not enough mac addresses\n");
  63                 return -ENODEV;
  64         }
  65
  66         memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
  67         oui = mac + ETH_ALEN/2 - 1;
  68         count = mac_addr_used;
  69
  70         while (count--) {
  71                 u8 *p = mac + ETH_ALEN - 1;
  72
  73                 do {
  74                         (*p)++;
  75                         if (*p != 0)
  76                                 break;
  77                         p--;
  78                 } while (p != oui);
  79
  80                 if (p == oui) {
  81                         pr_err("unable to fetch mac address\n");
  82                         return -ENODEV;
  83                 }
  84         }
  85
  86         mac_addr_used++;
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);
  90
  91 int bcm63xx_nvram_get_psi_size(void)
  92 {
  93         if (nvram.psi_size > 0)
  94                 return nvram.psi_size;
  95
  96         return BCM63XX_DEFAULT_PSI_SIZE;
  97 }
  98 EXPORT_SYMBOL(bcm63xx_nvram_get_psi_size);