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| 2 | |
| 3 | * OpenRISC Linux
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| 4 | *
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| 5 | * Linux architectural port borrowing liberally from similar works of
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| 6 | * others. All original copyrights apply as per the original source
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| 7 | * declaration.
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| 8 | *
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| 9 | * Modifications for the OpenRISC architecture:
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| 10 | * Copyright (C) 2010-2011 Jonas Bonn <[email protected]>
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| 11 | *
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| 12 | * Precise Delay Loops
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| 13 |
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| 14 |
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| 15 | #include <linux/kernel.h>
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| 16 | #include <linux/delay.h>
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| 17 | #include <linux/export.h>
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| 18 | #include <linux/init.h>
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| 19 |
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| 20 | #include <asm/param.h>
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| 21 | #include <asm/processor.h>
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| 22 |
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| 23 | bool delay_read_timer(unsigned long *timer_value)
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| 24 | {
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| 25 | *timer_value = get_cycles();
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| 26 | return true;
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| 27 | }
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| 28 |
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| 29 | void __delay(unsigned long cycles)
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| 30 | {
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| 31 | cycles_t start = get_cycles();
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| 32 |
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| 33 | while ((get_cycles() - start) < cycles)
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| 34 | cpu_relax();
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| 35 | }
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| 36 | EXPORT_SYMBOL(__delay);
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| 37 |
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| 38 | inline void __const_udelay(unsigned long xloops)
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| 39 | {
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| 40 | unsigned long long loops;
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| 41 |
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| 42 | loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
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| 43 |
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| 44 | __delay(loops >> 32);
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| 45 | }
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| 46 | EXPORT_SYMBOL(__const_udelay);
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| 47 |
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| 48 | void __udelay(unsigned long usecs)
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| 49 | {
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| 50 | __const_udelay(usecs * 0x10C7UL);
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| 51 | }
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| 52 | EXPORT_SYMBOL(__udelay);
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| 53 |
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| 54 | void __ndelay(unsigned long nsecs)
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| 55 | {
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| 56 | __const_udelay(nsecs * 0x5UL);
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| 57 | }
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| 58 | EXPORT_SYMBOL(__ndelay);
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