#ifndef _LINUX_DELAY_H #define _LINUX_DELAY_H /* * Copyright (C) 1993 Linus Torvalds * * Delay routines, using a pre-computed "loops_per_second" value. */ extern unsigned long loops_per_sec; extern __inline__ void __delay(int loops) { __asm__(".align 2,0x90\n1:\tdecl %0\n\tjns 1b": :"a" (loops):"ax"); } /* * division by multiplication: you don't have to worry about * loss of precision. * * Use only for very small delays ( < 1 msec). Should probably use a * lookup table, really, as the multiplications take much too long with * short delays. This is a "reasonable" implementation, though (and the * first constant multiplications gets optimized away if the delay is * a constant) */ extern __inline__ void udelay(unsigned long usecs) { usecs *= 0x000010c6; /* 2**32 / 1000000 */ __asm__("mull %0" :"=d" (usecs) :"a" (usecs),"0" (loops_per_sec) :"ax"); __delay(usecs); } #endif