arch/mips/jz4740/reset.c

   1 /*
   2  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *
   4  *  This program is free software; you can redistribute it and/or modify it
   5  *  under  the terms of the GNU General  Public License as published by the
   6  *  Free Software Foundation;  either version 2 of the License, or (at your
   7  *  option) any later version.
   8  *
   9  *  You should have received a copy of the GNU General Public License along
  10  *  with this program; if not, write to the Free Software Foundation, Inc.,
  11  *  675 Mass Ave, Cambridge, MA 02139, USA.
  12  *
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/pm.h>
  19
  20 #include <asm/reboot.h>
  21
  22 #include <asm/mach-jz4740/base.h>
  23 #include <asm/mach-jz4740/timer.h>
  24
  25 #include "reset.h"
  26 #include "clock.h"
  27
  28 static void jz4740_halt(void)
  29 {
  30         while (1) {
  31                 __asm__(".set push;\n"
  32                         ".set mips3;\n"
  33                         "wait;\n"
  34                         ".set pop;\n"
  35                 );
  36         }
  37 }
  38
  39 #define JZ_REG_WDT_DATA 0x00
  40 #define JZ_REG_WDT_COUNTER_ENABLE 0x04
  41 #define JZ_REG_WDT_COUNTER 0x08
  42 #define JZ_REG_WDT_CTRL 0x0c
  43
  44 static void jz4740_restart(char *command)
  45 {
  46         void __iomem *wdt_base = ioremap(JZ4740_WDT_BASE_ADDR, 0x0f);
  47
  48         jz4740_timer_enable_watchdog();
  49
  50         writeb(0, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
  51
  52         writew(0, wdt_base + JZ_REG_WDT_COUNTER);
  53         writew(0, wdt_base + JZ_REG_WDT_DATA);
  54         writew(BIT(2), wdt_base + JZ_REG_WDT_CTRL);
  55
  56         writeb(1, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
  57         jz4740_halt();
  58 }
  59
  60 void jz4740_reset_init(void)
  61 {
  62         _machine_restart = jz4740_restart;
  63         _machine_halt = jz4740_halt;
  64 }