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
  19 #include <mach/map.h>
  20 #include <plat/cpu.h>
  21
  22 unsigned long samsung_cpu_id;
  23 static unsigned int samsung_cpu_rev;
  24
  25 unsigned int samsung_rev(void)
  26 {
  27         return samsung_cpu_rev;
  28 }
  29 EXPORT_SYMBOL(samsung_rev);
  30
  31 void __init s3c64xx_init_cpu(void)
  32 {
  33         samsung_cpu_id = __raw_readl(S3C_VA_SYS + 0x118);
  34         if (!samsung_cpu_id) {
  35                 /*
  36                  * S3C6400 has the ID register in a different place,
  37                  * and needs a write before it can be read.
  38                  */
  39                 __raw_writel(0x0, S3C_VA_SYS + 0xA1C);
  40                 samsung_cpu_id = __raw_readl(S3C_VA_SYS + 0xA1C);
  41         }
  42
  43         samsung_cpu_rev = 0;
  44 }
  45
  46 void __init s5p_init_cpu(void __iomem *cpuid_addr)
  47 {
  48         samsung_cpu_id = __raw_readl(cpuid_addr);
  49         samsung_cpu_rev = samsung_cpu_id & 0xFF;
  50 }