1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/init.h>
6 #include <linux/delay.h>
7
8 void __aligned(8) __delay(unsigned long loops)
9 {
10 asm volatile (
11 "mov r0, r0\n"
12 "1:declt %0\n"
13 "bf 1b"
14 : "=r"(loops)
15 : ""(loops));
16 }
17 EXPORT_SYMBOL(__delay);
18
19 void __const_udelay(unsigned long xloops)
20 {
21 unsigned long long loops;
22
23 loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
24
25 __delay(loops >> 32);
26 }
27 EXPORT_SYMBOL(__const_udelay);
28
29 void __udelay(unsigned long usecs)
30 {
31 __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
32 }
33 EXPORT_SYMBOL(__udelay);
34
35 void __ndelay(unsigned long nsecs)
36 {
37 __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
38 }
39 EXPORT_SYMBOL(__ndelay);
40
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