xref: /linux/arch/arm/mach-imx/system.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 
32 static void __iomem *wdog_base;
33 
34 /*
35  * Reset the system. It is called by machine_restart().
36  */
37 void 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 
67 void mxc_arch_reset_init(void __iomem *base)
68 {
69 	wdog_base = base;
70 }
71