46 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef __ASM_GENERIC_DELAY_H3#define __ASM_GENERIC_DELAY_H4 5/* Undefined functions to get compile-time errors */6extern void __bad_udelay(void);7extern void __bad_ndelay(void);8 9extern void __udelay(unsigned long usecs);10extern void __ndelay(unsigned long nsecs);11extern void __const_udelay(unsigned long xloops);12extern void __delay(unsigned long loops);13 14/*15 * The weird n/20000 thing suppresses a "comparison is always false due to16 * limited range of data type" warning with non-const 8-bit arguments.17 */18 19/* 0x10c7 is 2**32 / 1000000 (rounded up) */20#define udelay(n) \21 ({ \22 if (__builtin_constant_p(n)) { \23 if ((n) / 20000 >= 1) \24 __bad_udelay(); \25 else \26 __const_udelay((n) * 0x10c7ul); \27 } else { \28 __udelay(n); \29 } \30 })31 32/* 0x5 is 2**32 / 1000000000 (rounded up) */33#define ndelay(n) \34 ({ \35 if (__builtin_constant_p(n)) { \36 if ((n) / 20000 >= 1) \37 __bad_ndelay(); \38 else \39 __const_udelay((n) * 5ul); \40 } else { \41 __ndelay(n); \42 } \43 })44 45#endif /* __ASM_GENERIC_DELAY_H */46