| #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__("\n1:\tdecl %0\n\tjns 1b\n": :"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 |