4a3ec00957
Specify 8 bytes alignment for the function __delay or we get bad delay like udelay(10) will be 25us in fact. Signed-off-by: Jialu Xu <xujialu@vimux.org> Signed-off-by: Guo Ren <guoren@kernel.org>
40 lines
825 B
C
40 lines
825 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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void __aligned(8) __delay(unsigned long loops)
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{
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asm volatile (
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"mov r0, r0\n"
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"1:declt %0\n"
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"bf 1b"
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: "=r"(loops)
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: "0"(loops));
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}
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EXPORT_SYMBOL(__delay);
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void __const_udelay(unsigned long xloops)
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{
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unsigned long long loops;
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loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
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__delay(loops >> 32);
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}
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EXPORT_SYMBOL(__const_udelay);
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void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
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}
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EXPORT_SYMBOL(__udelay);
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void __ndelay(unsigned long nsecs)
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{
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__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
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}
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EXPORT_SYMBOL(__ndelay);
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