arch/arm/mach-s3c/cpu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (c) 2009-2011 Samsung Electronics Co., Ltd.
   4 //              http://www.samsung.com
   5 //
   6 // Samsung CPU Support
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12
  13 #include <mach/map-base.h>
  14 #include "cpu.h"
  15
  16 unsigned long samsung_cpu_id;
  17
  18 void __init s3c64xx_init_cpu(void)
  19 {
  20         samsung_cpu_id = readl_relaxed(S3C_VA_SYS + 0x118);
  21         if (!samsung_cpu_id) {
  22                 /*
  23                  * S3C6400 has the ID register in a different place,
  24                  * and needs a write before it can be read.
  25                  */
  26                 writel_relaxed(0x0, S3C_VA_SYS + 0xA1C);
  27                 samsung_cpu_id = readl_relaxed(S3C_VA_SYS + 0xA1C);
  28         }
  29
  30         pr_info("Samsung CPU ID: 0x%08lx\n", samsung_cpu_id);
  31 }