| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) */ |