58 строки
1.3 KiB
C
58 строки
1.3 KiB
C
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#ifndef _M68K_DELAY_H
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#define _M68K_DELAY_H
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#include <asm/param.h>
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/*
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* Copyright (C) 1994 Hamish Macdonald
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*
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* Delay routines, using a pre-computed "loops_per_jiffy" value.
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*/
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static inline void __delay(unsigned long loops)
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{
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__asm__ __volatile__ ("1: subql #1,%0; jcc 1b"
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: "=d" (loops) : "0" (loops));
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}
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extern void __bad_udelay(void);
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/*
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* Use only for very small delays ( < 1 msec). Should probably use a
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* lookup table, really, as the multiplications take much too long with
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* short delays. This is a "reasonable" implementation, though (and the
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* first constant multiplications gets optimized away if the delay is
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* a constant)
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*/
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static inline void __const_udelay(unsigned long xloops)
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{
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unsigned long tmp;
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__asm__ ("mulul %2,%0:%1"
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: "=d" (xloops), "=d" (tmp)
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: "d" (xloops), "1" (loops_per_jiffy));
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__delay(xloops * HZ);
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}
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static inline void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 4295); /* 2**32 / 1000000 */
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}
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#define udelay(n) (__builtin_constant_p(n) ? \
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((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 4295)) : \
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__udelay(n))
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static inline unsigned long muldiv(unsigned long a, unsigned long b,
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unsigned long c)
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{
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unsigned long tmp;
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__asm__ ("mulul %2,%0:%1; divul %3,%0:%1"
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: "=d" (tmp), "=d" (a)
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: "d" (b), "d" (c), "1" (a));
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return a;
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}
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#endif /* defined(_M68K_DELAY_H) */
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