diff options
Diffstat (limited to 'arch/m68k/include/asm/delay_mm.h')
-rw-r--r-- | arch/m68k/include/asm/delay_mm.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/m68k/include/asm/delay_mm.h b/arch/m68k/include/asm/delay_mm.h new file mode 100644 index 0000000..5ed9285 --- /dev/null +++ b/arch/m68k/include/asm/delay_mm.h @@ -0,0 +1,57 @@ +#ifndef _M68K_DELAY_H +#define _M68K_DELAY_H + +#include <asm/param.h> + +/* + * Copyright (C) 1994 Hamish Macdonald + * + * Delay routines, using a pre-computed "loops_per_jiffy" value. + */ + +static inline void __delay(unsigned long loops) +{ + __asm__ __volatile__ ("1: subql #1,%0; jcc 1b" + : "=d" (loops) : "0" (loops)); +} + +extern void __bad_udelay(void); + +/* + * 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) + */ +static inline void __const_udelay(unsigned long xloops) +{ + unsigned long tmp; + + __asm__ ("mulul %2,%0:%1" + : "=d" (xloops), "=d" (tmp) + : "d" (xloops), "1" (loops_per_jiffy)); + __delay(xloops * HZ); +} + +static inline void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 4295); /* 2**32 / 1000000 */ +} + +#define udelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 4295)) : \ + __udelay(n)) + +static inline unsigned long muldiv(unsigned long a, unsigned long b, + unsigned long c) +{ + unsigned long tmp; + + __asm__ ("mulul %2,%0:%1; divul %3,%0:%1" + : "=d" (tmp), "=d" (a) + : "d" (b), "d" (c), "1" (a)); + return a; +} + +#endif /* defined(_M68K_DELAY_H) */ |