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1da177e4 LT |
1 | /* |
2 | * include/asm-v850/delay.h -- Delay routines, using a pre-computed | |
3 | * "loops_per_second" value | |
4 | * | |
5 | * Copyright (C) 2001,03 NEC Corporation | |
6 | * Copyright (C) 2001,03 Miles Bader <miles@gnu.org> | |
7 | * Copyright (C) 1994 Hamish Macdonald | |
8 | * | |
9 | * This file is subject to the terms and conditions of the GNU General | |
10 | * Public License. See the file COPYING in the main directory of this | |
11 | * archive for more details. | |
12 | */ | |
13 | ||
14 | #ifndef __V850_DELAY_H__ | |
15 | #define __V850_DELAY_H__ | |
16 | ||
17 | #include <asm/param.h> | |
18 | ||
19 | extern __inline__ void __delay(unsigned long loops) | |
20 | { | |
21 | if (loops) | |
22 | __asm__ __volatile__ ("1: add -1, %0; bnz 1b" | |
23 | : "=r" (loops) : "0" (loops)); | |
24 | } | |
25 | ||
26 | /* | |
27 | * Use only for very small delays ( < 1 msec). Should probably use a | |
28 | * lookup table, really, as the multiplications take much too long with | |
29 | * short delays. This is a "reasonable" implementation, though (and the | |
30 | * first constant multiplications gets optimized away if the delay is | |
31 | * a constant) | |
32 | */ | |
33 | ||
34 | extern unsigned long loops_per_jiffy; | |
35 | ||
36 | extern __inline__ void udelay(unsigned long usecs) | |
37 | { | |
38 | register unsigned long full_loops, part_loops; | |
39 | ||
40 | full_loops = ((usecs * HZ) / 1000000) * loops_per_jiffy; | |
41 | usecs %= (1000000 / HZ); | |
42 | part_loops = (usecs * HZ * loops_per_jiffy) / 1000000; | |
43 | ||
44 | __delay(full_loops + part_loops); | |
45 | } | |
46 | ||
47 | #endif /* __V850_DELAY_H__ */ |