/*
   * BCM947xx nvram variable access
   *
   * Copyright (C) 2005 Broadcom Corporation
   * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>

   * Copyright (C) 2010-2011 Hauke Mehrtens <hauke@hauke-m.de>

   *
   * 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/types.h>
  #include <linux/module.h>
  #include <linux/ssb/ssb.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <asm/addrspace.h>
  #include <asm/mach-bcm47xx/nvram.h>
  #include <asm/mach-bcm47xx/bcm47xx.h>
  
  static char nvram_buf[NVRAM_SPACE];
  
  /* Probe for NVRAM header */

  static void early_nvram_init(void)

  {

  #ifdef CONFIG_BCM47XX_SSB

  	struct ssb_mipscore *mcore_ssb;

  #endif

  #ifdef CONFIG_BCM47XX_BCMA
  	struct bcma_drv_cc *bcma_cc;
  #endif

  	struct nvram_header *header;
  	int i;

  	u32 base = 0;
  	u32 lim = 0;
  	u32 off;

  	u32 *src, *dst;

  	switch (bcm47xx_bus_type) {

  #ifdef CONFIG_BCM47XX_SSB

  	case BCM47XX_BUS_TYPE_SSB:
  		mcore_ssb = &bcm47xx_bus.ssb.mipscore;
  		base = mcore_ssb->flash_window;
  		lim = mcore_ssb->flash_window_size;
  		break;

  #endif

  #ifdef CONFIG_BCM47XX_BCMA
  	case BCM47XX_BUS_TYPE_BCMA:
  		bcma_cc = &bcm47xx_bus.bcma.bus.drv_cc;
  		base = bcma_cc->pflash.window;
  		lim = bcma_cc->pflash.window_size;
  		break;
  #endif

  	}

  
  	off = FLASH_MIN;
  	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++);
  }
  
  int nvram_getenv(char *name, char *val, size_t val_len)
  {
  	char *var, *value, *end, *eq;
  
  	if (!name)

  		return NVRAM_ERR_INV_PARAM;

  
  	if (!nvram_buf[0])
  		early_nvram_init();
  
  	/* 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) {
  		eq = strchr(var, '=');
  		if (!eq)
  			break;
  		value = eq + 1;
  		if ((eq - var) == strlen(name) &&
  			strncmp(var, name, (eq - var)) == 0) {
  			snprintf(val, val_len, "%s", value);
  			return 0;
  		}
  	}

  	return NVRAM_ERR_ENVNOTFOUND;

  }
  EXPORT_SYMBOL(nvram_getenv);