Openwrt/target/linux/brcm47xx/files/arch/mips/bcm947xx/nvram.c

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/*
* BCM947xx nvram variable access
*
* Copyright 2005, Broadcom Corporation
* Copyright 2006, Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ssb/ssb.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#include <asm/bootinfo.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <nvram.h>
#define MB * 1048576
extern struct ssb_bus ssb;
static char nvram_buf[NVRAM_SPACE];
static int cfe_env;
extern char *cfe_env_get(char *nv_buf, const char *name);
/* Probe for NVRAM header */
static void __init early_nvram_init(void)
{
struct ssb_mipscore *mcore = &ssb.mipscore;
struct nvram_header *header;
int i;
u32 base, lim, off;
u32 *src, *dst;
base = mcore->flash_window;
lim = mcore->flash_window_size;
cfe_env = 0;
/* XXX: hack for supporting the CFE environment stuff on WGT634U */
if (lim >= 8 MB) {
src = (u32 *) KSEG1ADDR(base + 8 MB - 0x2000);
dst = (u32 *) nvram_buf;
if ((*src & 0xff00ff) == 0x000001) {
printk("early_nvram_init: WGT634U NVRAM found.\n");
for (i = 0; i < 0x1ff0; i++) {
if (*src == 0xFFFFFFFF)
break;
*dst++ = *src++;
}
cfe_env = 1;
return;
}
}
off = 0x20000;
while (off <= lim) {
/* Windowed flash access */
header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
if (header->magic == NVRAM_HEADER)
goto found;
off <<= 1;
}
/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
header = (struct nvram_header *) KSEG1ADDR(base + 4096);
if (header->magic == NVRAM_HEADER)
goto found;
header = (struct nvram_header *) KSEG1ADDR(base + 1024);
if (header->magic == NVRAM_HEADER)
goto found;
return;
found:
src = (u32 *) header;
dst = (u32 *) nvram_buf;
for (i = 0; i < sizeof(struct nvram_header); i += 4)
*dst++ = *src++;
for (; i < header->len && i < NVRAM_SPACE; i += 4)
*dst++ = le32_to_cpu(*src++);
}
char *nvram_get(const char *name)
{
char *var, *value, *end, *eq;
if (!name)
return NULL;
if (!nvram_buf[0])
early_nvram_init();
if (cfe_env)
return cfe_env_get(nvram_buf, name);
/* Look for name=value and return value */
var = &nvram_buf[sizeof(struct nvram_header)];
end = nvram_buf + sizeof(nvram_buf) - 2;
end[0] = end[1] = '\0';
for (; *var; var = value + strlen(value) + 1) {
if (!(eq = strchr(var, '=')))
break;
value = eq + 1;
if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
return value;
}
return NULL;
}
EXPORT_SYMBOL(nvram_get);