| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | #ifndef _H8300_DELAY_H |
| 2 | #define _H8300_DELAY_H |
| 3 | |
| 4 | #include <asm/param.h> |
| 5 | |
| 6 | /* |
| 7 | * Copyright (C) 2002 Yoshinori Sato <ysato@sourceforge.jp> |
| 8 | * |
| 9 | * Delay routines, using a pre-computed "loops_per_second" value. |
| 10 | */ |
| 11 | |
| 12 | extern __inline__ void __delay(unsigned long loops) |
| 13 | { |
| 14 | __asm__ __volatile__ ("1:\n\t" |
| 15 | "dec.l #1,%0\n\t" |
| 16 | "bne 1b" |
| 17 | :"=r" (loops):"0"(loops)); |
| 18 | } |
| 19 | |
| 20 | /* |
| 21 | * Use only for very small delays ( < 1 msec). Should probably use a |
| 22 | * lookup table, really, as the multiplications take much too long with |
| 23 | * short delays. This is a "reasonable" implementation, though (and the |
| 24 | * first constant multiplications gets optimized away if the delay is |
| 25 | * a constant) |
| 26 | */ |
| 27 | |
| 28 | extern unsigned long loops_per_jiffy; |
| 29 | |
| 30 | extern __inline__ void udelay(unsigned long usecs) |
| 31 | { |
| 32 | usecs *= 4295; /* 2**32 / 1000000 */ |
| 33 | usecs /= (loops_per_jiffy*HZ); |
| 34 | if (usecs) |
| 35 | __delay(usecs); |
| 36 | } |
| 37 | |
| 38 | #endif /* _H8300_DELAY_H */ |