xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/arm920t/ep93xx/cpu.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Cirrus Logic EP93xx CPU-specific support.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Copyright (C) 2009 Matthias Kaehlcke <matthias@kaehlcke.net>
5*4882a593Smuzhiyun  *
6*4882a593Smuzhiyun  * Copyright (C) 2004, 2005
7*4882a593Smuzhiyun  * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com>
8*4882a593Smuzhiyun  *
9*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
10*4882a593Smuzhiyun  */
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <common.h>
13*4882a593Smuzhiyun #include <asm/arch/ep93xx.h>
14*4882a593Smuzhiyun #include <asm/io.h>
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun /* We reset the CPU by generating a 1-->0 transition on DeviceCfg bit 31. */
reset_cpu(ulong addr)17*4882a593Smuzhiyun extern void reset_cpu(ulong addr)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun 	struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE;
20*4882a593Smuzhiyun 	uint32_t value;
21*4882a593Smuzhiyun 
22*4882a593Smuzhiyun 	/* Unlock DeviceCfg and set SWRST */
23*4882a593Smuzhiyun 	writel(0xAA, &syscon->sysswlock);
24*4882a593Smuzhiyun 	value = readl(&syscon->devicecfg);
25*4882a593Smuzhiyun 	value |= SYSCON_DEVICECFG_SWRST;
26*4882a593Smuzhiyun 	writel(value, &syscon->devicecfg);
27*4882a593Smuzhiyun 
28*4882a593Smuzhiyun 	/* Unlock DeviceCfg and clear SWRST */
29*4882a593Smuzhiyun 	writel(0xAA, &syscon->sysswlock);
30*4882a593Smuzhiyun 	value = readl(&syscon->devicecfg);
31*4882a593Smuzhiyun 	value &= ~SYSCON_DEVICECFG_SWRST;
32*4882a593Smuzhiyun 	writel(value, &syscon->devicecfg);
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	/* Dying... */
35*4882a593Smuzhiyun 	while (1)
36*4882a593Smuzhiyun 		; /* noop */
37*4882a593Smuzhiyun }
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