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1da177e4 LT |
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 | ||
219576e1 | 12 | static inline void __delay(unsigned long loops) |
1da177e4 LT |
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 | ||
219576e1 | 30 | static inline void udelay(unsigned long usecs) |
1da177e4 LT |
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 */ |