1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * delay loops
4  *
5  * Copyright (C) 2015 Yoshinori Sato
6  */
7 
8 #include <linux/module.h>
9 #include <linux/delay.h>
10 #include <asm/param.h>
11 #include <asm/processor.h>
12 #include <asm/timex.h>
13 
__delay(unsigned long cycles)14 void __delay(unsigned long cycles)
15 {
16 	__asm__ volatile ("1: dec.l #1,%0\n\t"
17 			  "bne 1b":"=r"(cycles):"0"(cycles));
18 }
19 EXPORT_SYMBOL(__delay);
20 
__const_udelay(unsigned long xloops)21 void __const_udelay(unsigned long xloops)
22 {
23 	u64 loops;
24 
25 	loops = (u64)xloops * loops_per_jiffy * HZ;
26 
27 	__delay(loops >> 32);
28 }
29 EXPORT_SYMBOL(__const_udelay);
30 
__udelay(unsigned long usecs)31 void __udelay(unsigned long usecs)
32 {
33 	__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
34 }
35 EXPORT_SYMBOL(__udelay);
36 
__ndelay(unsigned long nsecs)37 void __ndelay(unsigned long nsecs)
38 {
39 	__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
40 }
41 EXPORT_SYMBOL(__ndelay);
42