arch/arm/mach-imx/cpu-imx35.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MX35 CPU type detection
   4  *
   5  * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/of_address.h>
   9 #include <linux/io.h>
  10
  11 #include "hardware.h"
  12 #include "iim.h"
  13
  14 static int mx35_cpu_rev = -1;
  15
  16 static int mx35_read_cpu_rev(void)
  17 {
  18         void __iomem *iim_base;
  19         struct device_node *np;
  20         u32 rev;
  21
  22         np = of_find_compatible_node(NULL, NULL, "fsl,imx35-iim");
  23         iim_base = of_iomap(np, 0);
  24         of_node_put(np);
  25         BUG_ON(!iim_base);
  26
  27         rev = imx_readl(iim_base + MXC_IIMSREV);
  28         switch (rev) {
  29         case 0x00:
  30                 return IMX_CHIP_REVISION_1_0;
  31         case 0x10:
  32                 return IMX_CHIP_REVISION_2_0;
  33         case 0x11:
  34                 return IMX_CHIP_REVISION_2_1;
  35         default:
  36                 return IMX_CHIP_REVISION_UNKNOWN;
  37         }
  38 }
  39
  40 int mx35_revision(void)
  41 {
  42         if (mx35_cpu_rev == -1)
  43                 mx35_cpu_rev = mx35_read_cpu_rev();
  44
  45         return mx35_cpu_rev;
  46 }
  47 EXPORT_SYMBOL(mx35_revision);