1 /* 2 * SPDX-License-Identifier: GPL-2.0+ 3 */ 4 5 #ifndef _TIME_H 6 #define _TIME_H 7 8 #include <linux/typecheck.h> 9 10 unsigned long get_timer(unsigned long base); 11 12 /* 13 * Return the current value of a monotonically increasing microsecond timer. 14 * Granularity may be larger than 1us if hardware does not support this. 15 */ 16 unsigned long timer_get_us(void); 17 18 /* 19 * These inlines deal with timer wrapping correctly. You are 20 * strongly encouraged to use them 21 * 1. Because people otherwise forget 22 * 2. Because if the timer wrap changes in future you won't have to 23 * alter your driver code. 24 * 25 * time_after(a,b) returns true if the time a is after time b. 26 * 27 * Do this with "<0" and ">=0" to only test the sign of the result. A 28 * good compiler would generate better code (and a really good compiler 29 * wouldn't care). Gcc is currently neither. 30 */ 31 #define time_after(a,b) \ 32 (typecheck(unsigned long, a) && \ 33 typecheck(unsigned long, b) && \ 34 ((long)((b) - (a)) < 0)) 35 #define time_before(a,b) time_after(b,a) 36 37 #define time_after_eq(a,b) \ 38 (typecheck(unsigned long, a) && \ 39 typecheck(unsigned long, b) && \ 40 ((long)((a) - (b)) >= 0)) 41 #define time_before_eq(a,b) time_after_eq(b,a) 42 43 /* 44 * Calculate whether a is in the range of [b, c]. 45 */ 46 #define time_in_range(a,b,c) \ 47 (time_after_eq(a,b) && \ 48 time_before_eq(a,c)) 49 50 /* 51 * Calculate whether a is in the range of [b, c). 52 */ 53 #define time_in_range_open(a,b,c) \ 54 (time_after_eq(a,b) && \ 55 time_before(a,c)) 56 57 #endif /* _TIME_H */ 58