arch/arm/cpu/arm920t/ep93xx/cpu.c

   1 /*
   2  * Cirrus Logic EP93xx CPU-specific support.
   3  *
   4  * Copyright (C) 2009 Matthias Kaehlcke <matthias@kaehlcke.net>
   5  *
   6  * Copyright (C) 2004, 2005
   7  * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com>
   8  *
   9  * See file CREDITS for list of people who contributed to this project.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  18  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  19  * for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <common.h>
  27 #include <asm/arch/ep93xx.h>
  28 #include <asm/io.h>
  29
  30 /* We reset the CPU by generating a 1-->0 transition on DeviceCfg bit 31. */
  31 extern void reset_cpu(ulong addr)
  32 {
  33         struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE;
  34         uint32_t value;
  35
  36         /* Unlock DeviceCfg and set SWRST */
  37         writel(0xAA, &syscon->sysswlock);
  38         value = readl(&syscon->devicecfg);
  39         value |= SYSCON_DEVICECFG_SWRST;
  40         writel(value, &syscon->devicecfg);
  41
  42         /* Unlock DeviceCfg and clear SWRST */
  43         writel(0xAA, &syscon->sysswlock);
  44         value = readl(&syscon->devicecfg);
  45         value &= ~SYSCON_DEVICECFG_SWRST;
  46         writel(value, &syscon->devicecfg);
  47
  48         /* Dying... */
  49         while (1)
  50                 ; /* noop */
  51 }