linux-sg2042/arch/mips/bcm63xx/nvram.c

108 lines
2.1 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
* Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
* Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
*/
#define pr_fmt(fmt) "bcm63xx_nvram: " fmt
#include <linux/init.h>
#include <linux/crc32.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/if_ether.h>
#include <bcm63xx_nvram.h>
/*
* nvram structure
*/
struct bcm963xx_nvram {
u32 version;
u8 reserved1[256];
u8 name[16];
u32 main_tp_number;
u32 psi_size;
u32 mac_addr_count;
u8 mac_addr_base[ETH_ALEN];
u8 reserved2[2];
u32 checksum_old;
u8 reserved3[720];
u32 checksum_high;
};
static struct bcm963xx_nvram nvram;
static int mac_addr_used;
int __init bcm63xx_nvram_init(void *addr)
{
unsigned int check_len;
u32 crc, expected_crc;
/* extract nvram data */
memcpy(&nvram, addr, sizeof(nvram));
/* check checksum before using data */
if (nvram.version <= 4) {
check_len = offsetof(struct bcm963xx_nvram, reserved3);
expected_crc = nvram.checksum_old;
nvram.checksum_old = 0;
} else {
check_len = sizeof(nvram);
expected_crc = nvram.checksum_high;
nvram.checksum_high = 0;
}
crc = crc32_le(~0, (u8 *)&nvram, check_len);
if (crc != expected_crc)
return -EINVAL;
return 0;
}
u8 *bcm63xx_nvram_get_name(void)
{
return nvram.name;
}
EXPORT_SYMBOL(bcm63xx_nvram_get_name);
int bcm63xx_nvram_get_mac_address(u8 *mac)
{
u8 *oui;
int count;
if (mac_addr_used >= nvram.mac_addr_count) {
pr_err("not enough mac addresses\n");
return -ENODEV;
}
memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
oui = mac + ETH_ALEN/2 - 1;
count = mac_addr_used;
while (count--) {
u8 *p = mac + ETH_ALEN - 1;
do {
(*p)++;
if (*p != 0)
break;
p--;
} while (p != oui);
if (p == oui) {
pr_err("unable to fetch mac address\n");
return -ENODEV;
}
}
mac_addr_used++;
return 0;
}
EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);