aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-ebsa110/include/mach/system.h
blob: 350a028997efddc34c8a87606928a0ebc25eef85 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
/*
 *  arch/arm/mach-ebsa110/include/mach/system.h
 *
 *  Copyright (C) 1996-2000 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ASM_ARCH_SYSTEM_H
#define __ASM_ARCH_SYSTEM_H

/*
 * EBSA110 idling methodology:
 *
 * We can not execute the "wait for interrupt" instruction since that
 * will stop our MCLK signal (which provides the clock for the glue
 * logic, and therefore the timer interrupt).
 *
 * Instead, we spin, polling the IRQ_STAT register for the occurrence
 * of any interrupt with core clock down to the memory clock.
 */
static inline void arch_idle(void)
{
	const char *irq_stat = (char *)0xff000000;

	/* disable clock switching */
	asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc");

	/* wait for an interrupt to occur */
	while (!*irq_stat);

	/* enable clock switching */
	asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc");
}

#define arch_reset(mode)	cpu_reset(0x80000000)

#endif