mirror of https://gitee.com/openkylin/linux.git
52 lines
917 B
C
52 lines
917 B
C
/*
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* delay.h - delay functions
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*
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* Copyright (c) 2004-2007 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#ifndef __ASM_DELAY_H__
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#define __ASM_DELAY_H__
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#include <mach/anomaly.h>
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static inline void __delay(unsigned long loops)
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{
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__asm__ __volatile__ (
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"LSETUP(1f, 1f) LC0 = %0;"
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"1: NOP;"
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:
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: "a" (loops)
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: "LT0", "LB0", "LC0"
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);
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}
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#include <linux/param.h> /* needed for HZ */
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/*
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* close approximation borrowed from m68knommu to avoid 64-bit math
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*/
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#define HZSCALE (268435456 / (1000000/HZ))
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static inline unsigned long __to_delay(unsigned long scale)
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{
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extern unsigned long loops_per_jiffy;
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return (((scale * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6;
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}
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static inline void udelay(unsigned long usecs)
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{
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__delay(__to_delay(usecs));
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}
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static inline void ndelay(unsigned long nsecs)
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{
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__delay(__to_delay(1) * nsecs / 1000);
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}
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#define ndelay ndelay
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#endif
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