Linux Kernel  3.7.1
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system.c
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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, [email protected]
6  * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, [email protected]
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 <mach/hardware.h>
26 #include <mach/common.h>
27 #include <asm/system_misc.h>
28 #include <asm/proc-fns.h>
29 #include <asm/mach-types.h>
30 
31 static void __iomem *wdog_base;
32 
33 /*
34  * Reset the system. It is called by machine_restart().
35  */
36 void mxc_restart(char mode, const char *cmd)
37 {
38  unsigned int wcr_enable;
39 
40  if (cpu_is_mx1()) {
41  wcr_enable = (1 << 0);
42  } else {
43  struct clk *clk;
44 
45  clk = clk_get_sys("imx2-wdt.0", NULL);
46  if (!IS_ERR(clk))
47  clk_prepare_enable(clk);
48  wcr_enable = (1 << 2);
49  }
50 
51  /* Assert SRS signal */
52  __raw_writew(wcr_enable, wdog_base);
53 
54  /* wait for reset to assert... */
55  mdelay(500);
56 
57  printk(KERN_ERR "Watchdog reset failed to assert reset\n");
58 
59  /* delay to allow the serial port to show the message */
60  mdelay(50);
61 
62  /* we'll take a jump through zero as a poor second */
63  soft_restart(0);
64 }
65 
66 void mxc_arch_reset_init(void __iomem *base)
67 {
68  wdog_base = base;
69 }