arch/arm/mach-davinci/id.c

   1 /*
   2  * Davinci CPU identification code
   3  *
   4  * Copyright (C) 2006 Komal Shah <komal_shah802003@yahoo.com>
   5  *
   6  * Derived from OMAP1 CPU identification code.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/io.h>
  17
  18 #define JTAG_ID_BASE            IO_ADDRESS(0x01c40028)
  19
  20 static unsigned int davinci_revision;
  21
  22 struct davinci_id {
  23         u8      variant;        /* JTAG ID bits 31:28 */
  24         u16     part_no;        /* JTAG ID bits 27:12 */
  25         u32     manufacturer;   /* JTAG ID bits 11:1 */
  26         u32     type;           /* Cpu id bits [31:8], cpu class bits [7:0] */
  27 };
  28
  29 /* Register values to detect the DaVinci version */
  30 static struct davinci_id davinci_ids[] __initdata = {
  31         {
  32                 /* DM6446 */
  33                 .part_no      = 0xb700,
  34                 .variant      = 0x0,
  35                 .manufacturer = 0x017,
  36                 .type         = 0x64460000,
  37         },
  38         {
  39                 /* DM646X */
  40                 .part_no      = 0xb770,
  41                 .variant      = 0x0,
  42                 .manufacturer = 0x017,
  43                 .type         = 0x64670000,
  44         },
  45         {
  46                 /* DM355 */
  47                 .part_no        = 0xb73b,
  48                 .variant        = 0x0,
  49                 .manufacturer   = 0x00f,
  50                 .type           = 0x03550000,
  51         },
  52 };
  53
  54 /*
  55  * Get Device Part No. from JTAG ID register
  56  */
  57 static u16 __init davinci_get_part_no(void)
  58 {
  59         u32 dev_id, part_no;
  60
  61         dev_id = __raw_readl(JTAG_ID_BASE);
  62
  63         part_no = ((dev_id >> 12) & 0xffff);
  64
  65         return part_no;
  66 }
  67
  68 /*
  69  * Get Device Revision from JTAG ID register
  70  */
  71 static u8 __init davinci_get_variant(void)
  72 {
  73         u32 variant;
  74
  75         variant = __raw_readl(JTAG_ID_BASE);
  76
  77         variant = (variant >> 28) & 0xf;
  78
  79         return variant;
  80 }
  81
  82 unsigned int davinci_rev(void)
  83 {
  84         return davinci_revision >> 16;
  85 }
  86 EXPORT_SYMBOL(davinci_rev);
  87
  88 void __init davinci_check_revision(void)
  89 {
  90         int i;
  91         u16 part_no;
  92         u8 variant;
  93
  94         part_no = davinci_get_part_no();
  95         variant = davinci_get_variant();
  96
  97         /* First check only the major version in a safe way */
  98         for (i = 0; i < ARRAY_SIZE(davinci_ids); i++) {
  99                 if (part_no == (davinci_ids[i].part_no)) {
 100                         davinci_revision = davinci_ids[i].type;
 101                         break;
 102                 }
 103         }
 104
 105         /* Check if we can find the dev revision */
 106         for (i = 0; i < ARRAY_SIZE(davinci_ids); i++) {
 107                 if (part_no == davinci_ids[i].part_no &&
 108                     variant == davinci_ids[i].variant) {
 109                         davinci_revision = davinci_ids[i].type;
 110                         break;
 111                 }
 112         }
 113
 114         printk(KERN_INFO "DaVinci DM%04x variant 0x%x\n",
 115                davinci_rev(), variant);
 116 }