xref: /openbmc/u-boot/arch/arm/cpu/arm920t/ep93xx/cpu.c (revision 419adbfb)
1 /*
2  * Cirrus Logic EP93xx CPU-specific support.
3  *
4  * Copyright (C) 2009 Matthias Kaehlcke <matthias@kaehlcke.net>
5  *
6  * Copyright (C) 2004, 2005
7  * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com>
8  *
9  * See file CREDITS for list of people who contributed to this project.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
18  * or FITNESS FOR A PARTICULAR PURPOSE.	See the GNU General Public License
19  * for more details.
20  *
21  * You should have received a copy of the GNU General Public License along
22  * with this program; if not, write to the Free Software Foundation, Inc.,
23  * 675 Mass Ave, Cambridge, MA 02139, USA.
24  */
25 
26 #include <common.h>
27 #include <asm/arch/ep93xx.h>
28 #include <asm/io.h>
29 
30 /* We reset the CPU by generating a 1-->0 transition on DeviceCfg bit 31. */
31 extern void reset_cpu(ulong addr)
32 {
33 	struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE;
34 	uint32_t value;
35 
36 	/* Unlock DeviceCfg and set SWRST */
37 	writel(0xAA, &syscon->sysswlock);
38 	value = readl(&syscon->devicecfg);
39 	value |= SYSCON_DEVICECFG_SWRST;
40 	writel(value, &syscon->devicecfg);
41 
42 	/* Unlock DeviceCfg and clear SWRST */
43 	writel(0xAA, &syscon->sysswlock);
44 	value = readl(&syscon->devicecfg);
45 	value &= ~SYSCON_DEVICECFG_SWRST;
46 	writel(value, &syscon->devicecfg);
47 
48 	/* Dying... */
49 	while (1)
50 		; /* noop */
51 }
52