mirror of https://gitee.com/openkylin/linux.git
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/*
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* BCM947xx nvram variable access
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*
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* Copyright (C) 2005 Broadcom Corporation
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* Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/ssb/ssb.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <asm/addrspace.h>
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#include <asm/mach-bcm47xx/nvram.h>
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#include <asm/mach-bcm47xx/bcm47xx.h>
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static char nvram_buf[NVRAM_SPACE];
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/* Probe for NVRAM header */
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static void __init early_nvram_init(void)
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{
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struct ssb_mipscore *mcore = &ssb_bcm47xx.mipscore;
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struct nvram_header *header;
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int i;
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u32 base, lim, off;
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u32 *src, *dst;
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base = mcore->flash_window;
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lim = mcore->flash_window_size;
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off = FLASH_MIN;
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while (off <= lim) {
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/* Windowed flash access */
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header = (struct nvram_header *)
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KSEG1ADDR(base + off - NVRAM_SPACE);
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if (header->magic == NVRAM_HEADER)
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goto found;
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off <<= 1;
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}
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/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
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header = (struct nvram_header *) KSEG1ADDR(base + 4096);
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if (header->magic == NVRAM_HEADER)
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goto found;
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header = (struct nvram_header *) KSEG1ADDR(base + 1024);
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if (header->magic == NVRAM_HEADER)
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goto found;
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return;
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found:
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src = (u32 *) header;
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dst = (u32 *) nvram_buf;
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for (i = 0; i < sizeof(struct nvram_header); i += 4)
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*dst++ = *src++;
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for (; i < header->len && i < NVRAM_SPACE; i += 4)
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*dst++ = le32_to_cpu(*src++);
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}
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int nvram_getenv(char *name, char *val, size_t val_len)
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{
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char *var, *value, *end, *eq;
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if (!name)
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return NVRAM_ERR_INV_PARAM;
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if (!nvram_buf[0])
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early_nvram_init();
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/* Look for name=value and return value */
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var = &nvram_buf[sizeof(struct nvram_header)];
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end = nvram_buf + sizeof(nvram_buf) - 2;
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end[0] = end[1] = '\0';
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for (; *var; var = value + strlen(value) + 1) {
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eq = strchr(var, '=');
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if (!eq)
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break;
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value = eq + 1;
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if ((eq - var) == strlen(name) &&
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strncmp(var, name, (eq - var)) == 0) {
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snprintf(val, val_len, "%s", value);
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return 0;
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}
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}
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return NVRAM_ERR_ENVNOTFOUND;
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}
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EXPORT_SYMBOL(nvram_getenv);
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