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42 lines
1019 B
42 lines
1019 B
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited |
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*/ |
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#include <linux/delay.h> |
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#include <linux/export.h> |
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#include <linux/smp.h> |
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#include <linux/timex.h> |
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#include <asm/processor.h> |
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void __delay(unsigned long cycles) |
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{ |
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u64 t0 = get_cycles(); |
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while ((unsigned long)(get_cycles() - t0) < cycles) |
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cpu_relax(); |
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} |
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EXPORT_SYMBOL(__delay); |
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/* |
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* Division by multiplication: you don't have to worry about |
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* loss of precision. |
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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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void __udelay(unsigned long us) |
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{ |
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__delay((us * 0x000010c7ull * HZ * lpj_fine) >> 32); |
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} |
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EXPORT_SYMBOL(__udelay); |
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void __ndelay(unsigned long ns) |
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{ |
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__delay((ns * 0x00000005ull * HZ * lpj_fine) >> 32); |
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} |
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EXPORT_SYMBOL(__ndelay);
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