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 
__delay(unsigned long loops)8 void __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 		: "0"(loops));
16 }
17 EXPORT_SYMBOL(__delay);
18 
__const_udelay(unsigned long xloops)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 
__udelay(unsigned long usecs)29 void __udelay(unsigned long usecs)
30 {
31 	__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
32 }
33 EXPORT_SYMBOL(__udelay);
34 
__ndelay(unsigned long nsecs)35 void __ndelay(unsigned long nsecs)
36 {
37 	__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
38 }
39 EXPORT_SYMBOL(__ndelay);
40