Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/include/asm-arm/arch-ebsa110/system.h |
| 3 | * |
| 4 | * Copyright (C) 1996-2000 Russell King. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | #ifndef __ASM_ARCH_SYSTEM_H |
| 11 | #define __ASM_ARCH_SYSTEM_H |
| 12 | |
| 13 | /* |
| 14 | * EBSA110 idling methodology: |
| 15 | * |
| 16 | * We can not execute the "wait for interrupt" instruction since that |
| 17 | * will stop our MCLK signal (which provides the clock for the glue |
| 18 | * logic, and therefore the timer interrupt). |
| 19 | * |
| 20 | * Instead, we spin, polling the IRQ_STAT register for the occurrence |
| 21 | * of any interrupt with core clock down to the memory clock. |
| 22 | */ |
| 23 | static inline void arch_idle(void) |
| 24 | { |
| 25 | const char *irq_stat = (char *)0xff000000; |
| 26 | |
| 27 | /* disable clock switching */ |
| 28 | asm volatile ("mcr p15, 0, ip, c15, c2, 2" : : : "cc"); |
| 29 | |
| 30 | /* wait for an interrupt to occur */ |
| 31 | while (!*irq_stat); |
| 32 | |
| 33 | /* enable clock switching */ |
| 34 | asm volatile ("mcr p15, 0, ip, c15, c1, 2" : : : "cc"); |
| 35 | } |
| 36 | |
| 37 | #define arch_reset(mode) cpu_reset(0x80000000) |
| 38 | |
| 39 | #endif |