LXR linux/arch/arm/mach-imx/system.c

   1/*
   2 * Copyright (C) 1999 ARM Limited
   3 * Copyright (C) 2000 Deep Blue Solutions Ltd
   4 * Copyright 2006-2007 Freescale Semiconductor, Inc. All Rights Reserved.
   5 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
   6 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
   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 as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 */
  18
  19#include <linux/kernel.h>
  20#include <linux/clk.h>
  21#include <linux/io.h>
  22#include <linux/err.h>
  23#include <linux/delay.h>
  24
  25#include <asm/system_misc.h>
  26#include <asm/proc-fns.h>
  27#include <asm/mach-types.h>
  28
  29#include "common.h"
  30#include "hardware.h"
  31
  32static void __iomem *wdog_base;
  33
  34/*
  35 * Reset the system. It is called by machine_restart().
  36 */
  37void mxc_restart(char mode, const char *cmd)
  38{
  39        unsigned int wcr_enable;
  40
  41        if (cpu_is_mx1()) {
  42                wcr_enable = (1 << 0);
  43        } else {
  44                struct clk *clk;
  45
  46                clk = clk_get_sys("imx2-wdt.0", NULL);
  47                if (!IS_ERR(clk))
  48                        clk_prepare_enable(clk);
  49                wcr_enable = (1 << 2);
  50        }
  51
  52        /* Assert SRS signal */
  53        __raw_writew(wcr_enable, wdog_base);
  54
  55        /* wait for reset to assert... */
  56        mdelay(500);
  57
  58        printk(KERN_ERR "Watchdog reset failed to assert reset\n");
  59
  60        /* delay to allow the serial port to show the message */
  61        mdelay(50);
  62
  63        /* we'll take a jump through zero as a poor second */
  64        soft_restart(0);
  65}
  66
  67void mxc_arch_reset_init(void __iomem *base)
  68{
  69        wdog_base = base;
  70}
  71