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Diffstat (limited to 'include/asm-v850/delay.h')
| -rw-r--r-- | include/asm-v850/delay.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/include/asm-v850/delay.h b/include/asm-v850/delay.h new file mode 100644 index 00000000000..1ce65d48a7c --- /dev/null +++ b/include/asm-v850/delay.h @@ -0,0 +1,47 @@ +/* + * include/asm-v850/delay.h -- Delay routines, using a pre-computed + * "loops_per_second" value + * + * Copyright (C) 2001,03 NEC Corporation + * Copyright (C) 2001,03 Miles Bader <miles@gnu.org> + * Copyright (C) 1994 Hamish Macdonald + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ + +#ifndef __V850_DELAY_H__ +#define __V850_DELAY_H__ + +#include <asm/param.h> + +extern __inline__ void __delay(unsigned long loops) +{ + if (loops) + __asm__ __volatile__ ("1: add -1, %0; bnz 1b" + : "=r" (loops) : "0" (loops)); +} + +/* + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ + +extern unsigned long loops_per_jiffy; + +extern __inline__ void udelay(unsigned long usecs) +{ + register unsigned long full_loops, part_loops; + + full_loops = ((usecs * HZ) / 1000000) * loops_per_jiffy; + usecs %= (1000000 / HZ); + part_loops = (usecs * HZ * loops_per_jiffy) / 1000000; + + __delay(full_loops + part_loops); +} + +#endif /* __V850_DELAY_H__ */ |