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1da177e4 LT |
1 | #ifndef _M68K_DELAY_H |
2 | #define _M68K_DELAY_H | |
3 | ||
4 | #include <asm/param.h> | |
5 | ||
6 | /* | |
7 | * Copyright (C) 1994 Hamish Macdonald | |
8 | * | |
9 | * Delay routines, using a pre-computed "loops_per_jiffy" value. | |
10 | */ | |
11 | ||
12 | static inline void __delay(unsigned long loops) | |
13 | { | |
14 | __asm__ __volatile__ ("1: subql #1,%0; jcc 1b" | |
15 | : "=d" (loops) : "0" (loops)); | |
16 | } | |
17 | ||
18 | extern void __bad_udelay(void); | |
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 | static inline void __const_udelay(unsigned long xloops) | |
28 | { | |
29 | unsigned long tmp; | |
30 | ||
31 | __asm__ ("mulul %2,%0:%1" | |
32 | : "=d" (xloops), "=d" (tmp) | |
33 | : "d" (xloops), "1" (loops_per_jiffy)); | |
34 | __delay(xloops * HZ); | |
35 | } | |
36 | ||
37 | static inline void __udelay(unsigned long usecs) | |
38 | { | |
39 | __const_udelay(usecs * 4295); /* 2**32 / 1000000 */ | |
40 | } | |
41 | ||
42 | #define udelay(n) (__builtin_constant_p(n) ? \ | |
43 | ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 4295)) : \ | |
44 | __udelay(n)) | |
45 | ||
46 | static inline unsigned long muldiv(unsigned long a, unsigned long b, | |
47 | unsigned long c) | |
48 | { | |
49 | unsigned long tmp; | |
50 | ||
51 | __asm__ ("mulul %2,%0:%1; divul %3,%0:%1" | |
52 | : "=d" (tmp), "=d" (a) | |
53 | : "d" (b), "d" (c), "1" (a)); | |
54 | return a; | |
55 | } | |
56 | ||
57 | #endif /* defined(_M68K_DELAY_H) */ |