arch/arm/mach-imx/cpu-imx31.c

   1 /*
   2  * MX31 CPU type detection
   3  *
   4  * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/io.h>
  14 #include <mach/hardware.h>
  15 #include <mach/iim.h>
  16 #include <mach/common.h>
  17
  18 static int mx31_cpu_rev = -1;
  19
  20 static struct {
  21         u8 srev;
  22         const char *name;
  23         unsigned int rev;
  24 } mx31_cpu_type[] = {
  25         { .srev = 0x00, .name = "i.MX31(L)", .rev = IMX_CHIP_REVISION_1_0 },
  26         { .srev = 0x10, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
  27         { .srev = 0x11, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
  28         { .srev = 0x12, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
  29         { .srev = 0x13, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
  30         { .srev = 0x14, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_2 },
  31         { .srev = 0x15, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_2 },
  32         { .srev = 0x28, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_2_0 },
  33         { .srev = 0x29, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_2_0 },
  34 };
  35
  36 static int mx31_read_cpu_rev(void)
  37 {
  38         u32 i, srev;
  39
  40         /* read SREV register from IIM module */
  41         srev = __raw_readl(MX31_IO_ADDRESS(MX31_IIM_BASE_ADDR + MXC_IIMSREV));
  42         srev &= 0xff;
  43
  44         for (i = 0; i < ARRAY_SIZE(mx31_cpu_type); i++)
  45                 if (srev == mx31_cpu_type[i].srev) {
  46                         imx_print_silicon_rev(mx31_cpu_type[i].name,
  47                                                 mx31_cpu_type[i].rev);
  48                         return mx31_cpu_type[i].rev;
  49                 }
  50
  51         imx_print_silicon_rev("i.MX31", IMX_CHIP_REVISION_UNKNOWN);
  52         return IMX_CHIP_REVISION_UNKNOWN;
  53 }
  54
  55 int mx31_revision(void)
  56 {
  57         if (mx31_cpu_rev == -1)
  58                 mx31_cpu_rev = mx31_read_cpu_rev();
  59
  60         return mx31_cpu_rev;
  61 }
  62 EXPORT_SYMBOL(mx31_revision);