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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MX31 CPU type detection
   4  *
   5  * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/of_address.h>
  10 #include <linux/io.h>
  11
  12 #include "common.h"
  13 #include "hardware.h"
  14 #include "iim.h"
  15
  16 static int mx31_cpu_rev = -1;
  17
  18 static struct {
  19         u8 srev;
  20         const char *name;
  21         unsigned int rev;
  22 } mx31_cpu_type[] = {
  23         { .srev = 0x00, .name = "i.MX31(L)", .rev = IMX_CHIP_REVISION_1_0 },
  24         { .srev = 0x10, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
  25         { .srev = 0x11, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
  26         { .srev = 0x12, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_1 },
  27         { .srev = 0x13, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_1 },
  28         { .srev = 0x14, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_1_2 },
  29         { .srev = 0x15, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_1_2 },
  30         { .srev = 0x28, .name = "i.MX31",    .rev = IMX_CHIP_REVISION_2_0 },
  31         { .srev = 0x29, .name = "i.MX31L",   .rev = IMX_CHIP_REVISION_2_0 },
  32 };
  33
  34 static int mx31_read_cpu_rev(void)
  35 {
  36         void __iomem *iim_base;
  37         struct device_node *np;
  38         u32 i, srev;
  39
  40         np = of_find_compatible_node(NULL, NULL, "fsl,imx31-iim");
  41         iim_base = of_iomap(np, 0);
  42         BUG_ON(!iim_base);
  43
  44         /* read SREV register from IIM module */
  45         srev = imx_readl(iim_base + MXC_IIMSREV);
  46         srev &= 0xff;
  47
  48         for (i = 0; i < ARRAY_SIZE(mx31_cpu_type); i++)
  49                 if (srev == mx31_cpu_type[i].srev) {
  50                         imx_print_silicon_rev(mx31_cpu_type[i].name,
  51                                                 mx31_cpu_type[i].rev);
  52                         return mx31_cpu_type[i].rev;
  53                 }
  54
  55         imx_print_silicon_rev("i.MX31", IMX_CHIP_REVISION_UNKNOWN);
  56         return IMX_CHIP_REVISION_UNKNOWN;
  57 }
  58
  59 int mx31_revision(void)
  60 {
  61         if (mx31_cpu_rev == -1)
  62                 mx31_cpu_rev = mx31_read_cpu_rev();
  63
  64         return mx31_cpu_rev;
  65 }
  66 EXPORT_SYMBOL(mx31_revision);