45 строки
1.2 KiB
C
45 строки
1.2 KiB
C
#ifndef _BLACKFIN_DELAY_H
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#define _BLACKFIN_DELAY_H
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static inline void __delay(unsigned long loops)
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{
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/* FIXME: Currently the assembler doesn't recognize Loop Register Clobbers,
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uncomment this as soon those are implemented */
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/*
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__asm__ __volatile__ ( "\t LSETUP (1f,1f) LC0= %0\n\t"
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"1:\t NOP;\n\t"
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: :"a" (loops)
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: "LT0","LB0","LC0");
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*/
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__asm__ __volatile__("[--SP] = LC0;\n\t"
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"[--SP] = LT0;\n\t"
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"[--SP] = LB0;\n\t"
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"LSETUP (1f,1f) LC0 = %0;\n\t"
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"1:\t NOP;\n\t"
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"LB0 = [SP++];\n\t"
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"LT0 = [SP++];\n\t"
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"LC0 = [SP++];\n"
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:
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:"a" (loops));
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}
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#include <linux/param.h> /* needed for HZ */
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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 udelay(unsigned long usecs)
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{
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extern unsigned long loops_per_jiffy;
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__delay(usecs * loops_per_jiffy / (1000000 / HZ));
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}
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#endif /* defined(_BLACKFIN_DELAY_H) */
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