arch/arm/plat-samsung/cpu.c

   1 /* linux/arch/arm/plat-samsung/cpu.c
   2  *
   3  * Copyright (c) 2009-2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * Samsung CPU Support
   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 #include <plat/map-base.h>
  19 #include <plat/cpu.h>
  20
  21 unsigned long samsung_cpu_id;
  22 static unsigned int samsung_cpu_rev;
  23
  24 unsigned int samsung_rev(void)
  25 {
  26         return samsung_cpu_rev;
  27 }
  28 EXPORT_SYMBOL(samsung_rev);
  29
  30 void __init s3c64xx_init_cpu(void)
  31 {
  32         samsung_cpu_id = readl_relaxed(S3C_VA_SYS + 0x118);
  33         if (!samsung_cpu_id) {
  34                 /*
  35                  * S3C6400 has the ID register in a different place,
  36                  * and needs a write before it can be read.
  37                  */
  38                 writel_relaxed(0x0, S3C_VA_SYS + 0xA1C);
  39                 samsung_cpu_id = readl_relaxed(S3C_VA_SYS + 0xA1C);
  40         }
  41
  42         samsung_cpu_rev = 0;
  43
  44         pr_info("Samsung CPU ID: 0x%08lx\n", samsung_cpu_id);
  45 }
  46
  47 void __init s5p_init_cpu(const void __iomem *cpuid_addr)
  48 {
  49         samsung_cpu_id = readl_relaxed(cpuid_addr);
  50         samsung_cpu_rev = samsung_cpu_id & 0xFF;
  51
  52         pr_info("Samsung CPU ID: 0x%08lx\n", samsung_cpu_id);
  53 }