LXR linux/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/init.h>
  14#include <linux/crc32.h>
  15#include <linux/export.h>
  16#include <linux/kernel.h>
  17#include <linux/if_ether.h>
  18
  19#include <bcm63xx_nvram.h>
  20
  21/*
  22 * nvram structure
  23 */
  24struct bcm963xx_nvram {
  25        u32     version;
  26        u8      reserved1[256];
  27        u8      name[16];
  28        u32     main_tp_number;
  29        u32     psi_size;
  30        u32     mac_addr_count;
  31        u8      mac_addr_base[ETH_ALEN];
  32        u8      reserved2[2];
  33        u32     checksum_old;
  34        u8      reserved3[720];
  35        u32     checksum_high;
  36};
  37
  38#define BCM63XX_DEFAULT_PSI_SIZE        64
  39
  40static struct bcm963xx_nvram nvram;
  41static int mac_addr_used;
  42
  43void __init bcm63xx_nvram_init(void *addr)
  44{
  45        unsigned int check_len;
  46        u32 crc, expected_crc;
  47        u8 hcs_mac_addr[ETH_ALEN] = { 0x00, 0x10, 0x18, 0xff, 0xff, 0xff };
  48
  49        /* extract nvram data */
  50        memcpy(&nvram, addr, sizeof(nvram));
  51
  52        /* check checksum before using data */
  53        if (nvram.version <= 4) {
  54                check_len = offsetof(struct bcm963xx_nvram, reserved3);
  55                expected_crc = nvram.checksum_old;
  56                nvram.checksum_old = 0;
  57        } else {
  58                check_len = sizeof(nvram);
  59                expected_crc = nvram.checksum_high;
  60                nvram.checksum_high = 0;
  61        }
  62
  63        crc = crc32_le(~0, (u8 *)&nvram, check_len);
  64
  65        if (crc != expected_crc)
  66                pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
  67                        expected_crc, crc);
  68
  69        /* Cable modems have a different NVRAM which is embedded in the eCos
  70         * firmware and not easily extractible, give at least a MAC address
  71         * pool.
  72         */
  73        if (BCMCPU_IS_3368()) {
  74                memcpy(nvram.mac_addr_base, hcs_mac_addr, ETH_ALEN);
  75                nvram.mac_addr_count = 2;
  76        }
  77}
  78
  79u8 *bcm63xx_nvram_get_name(void)
  80{
  81        return nvram.name;
  82}
  83EXPORT_SYMBOL(bcm63xx_nvram_get_name);
  84
  85int bcm63xx_nvram_get_mac_address(u8 *mac)
  86{
  87        u8 *oui;
  88        int count;
  89
  90        if (mac_addr_used >= nvram.mac_addr_count) {
  91                pr_err("not enough mac addresses\n");
  92                return -ENODEV;
  93        }
  94
  95        memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
  96        oui = mac + ETH_ALEN/2 - 1;
  97        count = mac_addr_used;
  98
  99        while (count--) {
 100                u8 *p = mac + ETH_ALEN - 1;
 101
 102                do {
 103                        (*p)++;
 104                        if (*p != 0)
 105                                break;
 106                        p--;
 107                } while (p != oui);
 108
 109                if (p == oui) {
 110                        pr_err("unable to fetch mac address\n");
 111                        return -ENODEV;
 112                }
 113        }
 114
 115        mac_addr_used++;
 116        return 0;
 117}
 118EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);
 119
 120int bcm63xx_nvram_get_psi_size(void)
 121{
 122        if (nvram.psi_size > 0)
 123                return nvram.psi_size;
 124
 125        return BCM63XX_DEFAULT_PSI_SIZE;
 126}
 127EXPORT_SYMBOL(bcm63xx_nvram_get_psi_size);
 128