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Diffstat (limited to 'arch/h8300/include/asm/delay.h')
-rw-r--r-- | arch/h8300/include/asm/delay.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/h8300/include/asm/delay.h b/arch/h8300/include/asm/delay.h new file mode 100644 index 0000000..743beba --- /dev/null +++ b/arch/h8300/include/asm/delay.h @@ -0,0 +1,38 @@ +#ifndef _H8300_DELAY_H +#define _H8300_DELAY_H + +#include <asm/param.h> + +/* + * Copyright (C) 2002 Yoshinori Sato <ysato@sourceforge.jp> + * + * Delay routines, using a pre-computed "loops_per_second" value. + */ + +static inline void __delay(unsigned long loops) +{ + __asm__ __volatile__ ("1:\n\t" + "dec.l #1,%0\n\t" + "bne 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) +{ + usecs *= 4295; /* 2**32 / 1000000 */ + usecs /= (loops_per_jiffy*HZ); + if (usecs) + __delay(usecs); +} + +#endif /* _H8300_DELAY_H */ |