55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
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/*
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* Precise Delay Loops for avr32
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*
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* Copyright (C) 1993 Linus Torvalds
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* Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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* Copyright (C) 2005-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <asm/processor.h>
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#include <asm/sysreg.h>
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int read_current_timer(unsigned long *timer_value)
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{
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*timer_value = sysreg_read(COUNT);
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return 0;
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}
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void __delay(unsigned long loops)
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{
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unsigned bclock, now;
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bclock = sysreg_read(COUNT);
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do {
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now = sysreg_read(COUNT);
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} while ((now - bclock) < loops);
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}
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inline void __const_udelay(unsigned long xloops)
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{
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unsigned long long loops;
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asm("mulu.d %0, %1, %2"
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: "=r"(loops)
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: "r"(current_cpu_data.loops_per_jiffy * HZ), "r"(xloops));
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__delay(loops >> 32);
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}
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void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
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}
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void __ndelay(unsigned long nsecs)
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{
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__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
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}
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