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kernel/linux-rt-4.4.41/arch/arm/mach-imx/cpu-imx25.c 1.13 KB
5113f6f70   김현기   kernel add
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  /*
   * MX25 CPU type detection
   *
   * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved
   *
   * 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/module.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  #include "iim.h"
  #include "hardware.h"
  
  static int mx25_cpu_rev = -1;
  
  static int mx25_read_cpu_rev(void)
  {
  	u32 rev;
  	void __iomem *iim_base;
  	struct device_node *np;
  
  	np = of_find_compatible_node(NULL, NULL, "fsl,imx25-iim");
  	iim_base = of_iomap(np, 0);
  	BUG_ON(!iim_base);
  	rev = readl(iim_base + MXC_IIMSREV);
  	iounmap(iim_base);
  
  	switch (rev) {
  	case 0x00:
  		return IMX_CHIP_REVISION_1_0;
  	case 0x01:
  		return IMX_CHIP_REVISION_1_1;
  	default:
  		return IMX_CHIP_REVISION_UNKNOWN;
  	}
  }
  
  int mx25_revision(void)
  {
  	if (mx25_cpu_rev == -1)
  		mx25_cpu_rev = mx25_read_cpu_rev();
  
  	return mx25_cpu_rev;
  }
  EXPORT_SYMBOL(mx25_revision);