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/*
* 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");
}
#endif
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