mirror of https://gitee.com/openkylin/linux.git
51 lines
1.0 KiB
C
51 lines
1.0 KiB
C
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/* MN10300 Short delay interpolation routines
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <asm/div64.h>
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/*
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* basic delay loop
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*/
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void __delay(unsigned long loops)
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{
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int d0;
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asm volatile(
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" bra 1f \n"
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" .align 4 \n"
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"1: bra 2f \n"
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" .align 4 \n"
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"2: add -1,%0 \n"
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" bne 2b \n"
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: "=&d" (d0)
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: "0" (loops));
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}
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EXPORT_SYMBOL(__delay);
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/*
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* handle a delay specified in terms of microseconds
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*/
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void __udelay(unsigned long usecs)
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{
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signed long ioclk, stop;
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/* usecs * CLK / 1E6 */
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stop = __muldiv64u(usecs, MN10300_TSCCLK, 1000000);
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stop = TMTSCBC - stop;
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do {
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ioclk = TMTSCBC;
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} while (stop < ioclk);
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}
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EXPORT_SYMBOL(__udelay);
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