arch/arm/mach-imx/cpu-imx25.c

   1 /*
   2  * MX25 CPU type detection
   3  *
   4  * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   5  * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/io.h>
  14 #include <linux/of.h>
  15 #include <linux/of_address.h>
  16
  17 #include "iim.h"
  18 #include "hardware.h"
  19
  20 static int mx25_cpu_rev = -1;
  21
  22 static int mx25_read_cpu_rev(void)
  23 {
  24         u32 rev;
  25         void __iomem *iim_base;
  26         struct device_node *np;
  27
  28         np = of_find_compatible_node(NULL, NULL, "fsl,imx25-iim");
  29         iim_base = of_iomap(np, 0);
  30         BUG_ON(!iim_base);
  31         rev = readl(iim_base + MXC_IIMSREV);
  32         iounmap(iim_base);
  33
  34         switch (rev) {
  35         case 0x00:
  36                 return IMX_CHIP_REVISION_1_0;
  37         case 0x01:
  38                 return IMX_CHIP_REVISION_1_1;
  39         default:
  40                 return IMX_CHIP_REVISION_UNKNOWN;
  41         }
  42 }
  43
  44 int mx25_revision(void)
  45 {
  46         if (mx25_cpu_rev == -1)
  47                 mx25_cpu_rev = mx25_read_cpu_rev();
  48
  49         return mx25_cpu_rev;
  50 }
  51 EXPORT_SYMBOL(mx25_revision);