xref: /openbmc/linux/include/asm-generic/delay.h (revision 293d5b43)
1 #ifndef __ASM_GENERIC_DELAY_H
2 #define __ASM_GENERIC_DELAY_H
3 
4 /* Undefined functions to get compile-time errors */
5 extern void __bad_udelay(void);
6 extern void __bad_ndelay(void);
7 
8 extern void __udelay(unsigned long usecs);
9 extern void __ndelay(unsigned long nsecs);
10 extern void __const_udelay(unsigned long xloops);
11 extern void __delay(unsigned long loops);
12 
13 /*
14  * The weird n/20000 thing suppresses a "comparison is always false due to
15  * limited range of data type" warning with non-const 8-bit arguments.
16  */
17 
18 /* 0x10c7 is 2**32 / 1000000 (rounded up) */
19 #define udelay(n)							\
20 	({								\
21 		if (__builtin_constant_p(n)) {				\
22 			if ((n) / 20000 >= 1)				\
23 				 __bad_udelay();			\
24 			else						\
25 				__const_udelay((n) * 0x10c7ul);		\
26 		} else {						\
27 			__udelay(n);					\
28 		}							\
29 	})
30 
31 /* 0x5 is 2**32 / 1000000000 (rounded up) */
32 #define ndelay(n)							\
33 	({								\
34 		if (__builtin_constant_p(n)) {				\
35 			if ((n) / 20000 >= 1)				\
36 				__bad_ndelay();				\
37 			else						\
38 				__const_udelay((n) * 5ul);		\
39 		} else {						\
40 			__ndelay(n);					\
41 		}							\
42 	})
43 
44 #endif /* __ASM_GENERIC_DELAY_H */
45