1 /* SPDX-License-Identifier: GPL-2.0 */
2 // Copyright (C) 2005-2017 Andes Technology Corporation
3 
4 #ifndef __NDS32_DELAY_H__
5 #define __NDS32_DELAY_H__
6 
7 #include <asm/param.h>
8 
9 /* There is no clocksource cycle counter in the CPU. */
__delay(unsigned long loops)10 static inline void __delay(unsigned long loops)
11 {
12 	__asm__ __volatile__(".align 2\n"
13 			     "1:\n"
14 			     "\taddi\t%0, %0, -1\n"
15 			     "\tbgtz\t%0, 1b\n"
16 			     :"=r"(loops)
17 			     :"0"(loops));
18 }
19 
__udelay(unsigned long usecs,unsigned long lpj)20 static inline void __udelay(unsigned long usecs, unsigned long lpj)
21 {
22 	usecs *= (unsigned long)(((0x8000000000000000ULL / (500000 / HZ)) +
23 				  0x80000000ULL) >> 32);
24 	usecs = (unsigned long)(((unsigned long long)usecs * lpj) >> 32);
25 	__delay(usecs);
26 }
27 
28 #define udelay(usecs) __udelay((usecs), loops_per_jiffy)
29 
30 /* make sure "usecs *= ..." in udelay do not overflow. */
31 #if HZ >= 1000
32 #define MAX_UDELAY_MS	1
33 #elif HZ <= 200
34 #define MAX_UDELAY_MS	5
35 #else
36 #define MAX_UDELAY_MS	(1000 / HZ)
37 #endif
38 
39 #endif
40