/* * 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> static 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; static 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__ */