kernel/2.6.29.6-aldebaran-rt/arch/arm/mach-mx2/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  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/clk.h>
  24 #include <linux/io.h>
  25
  26 #include <mach/hardware.h>
  27 #include <asm/proc-fns.h>
  28 #include <asm/system.h>
  29
  30 /*
  31  * Put the CPU into idle mode. It is called by default_idle()
  32  * in process.c file.
  33  */
  34 void arch_idle(void)
  35 {
  36         /*
  37          * This should do all the clock switching
  38          * and wait for interrupt tricks.
  39          */
  40         cpu_do_idle();
  41 }
  42
  43 #define WDOG_WCR_REG                    IO_ADDRESS(WDOG_BASE_ADDR)
  44 #define WDOG_WCR_SRS                    (1 << 4)
  45
  46 /*
  47  * Reset the system. It is called by machine_restart().
  48  */
  49 void arch_reset(char mode)
  50 {
  51         struct clk *clk;
  52
  53         clk = clk_get(NULL, "wdog_clk");
  54         if (!clk) {
  55                 printk(KERN_ERR"Cannot activate the watchdog. Giving up\n");
  56                 return;
  57         }
  58
  59         clk_enable(clk);
  60
  61         /* Assert SRS signal */
  62         __raw_writew(__raw_readw(WDOG_WCR_REG) & ~WDOG_WCR_SRS, WDOG_WCR_REG);
  63 }