1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+ 3*4882a593Smuzhiyun */ 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #ifndef _TIME_H 6*4882a593Smuzhiyun #define _TIME_H 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun #include <linux/typecheck.h> 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun unsigned long get_timer(unsigned long base); 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun /* 13*4882a593Smuzhiyun * Return the current value of a monotonically increasing microsecond timer. 14*4882a593Smuzhiyun * Granularity may be larger than 1us if hardware does not support this. 15*4882a593Smuzhiyun */ 16*4882a593Smuzhiyun unsigned long timer_get_us(void); 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun /* 19*4882a593Smuzhiyun * These inlines deal with timer wrapping correctly. You are 20*4882a593Smuzhiyun * strongly encouraged to use them 21*4882a593Smuzhiyun * 1. Because people otherwise forget 22*4882a593Smuzhiyun * 2. Because if the timer wrap changes in future you won't have to 23*4882a593Smuzhiyun * alter your driver code. 24*4882a593Smuzhiyun * 25*4882a593Smuzhiyun * time_after(a,b) returns true if the time a is after time b. 26*4882a593Smuzhiyun * 27*4882a593Smuzhiyun * Do this with "<0" and ">=0" to only test the sign of the result. A 28*4882a593Smuzhiyun * good compiler would generate better code (and a really good compiler 29*4882a593Smuzhiyun * wouldn't care). Gcc is currently neither. 30*4882a593Smuzhiyun */ 31*4882a593Smuzhiyun #define time_after(a,b) \ 32*4882a593Smuzhiyun (typecheck(unsigned long, a) && \ 33*4882a593Smuzhiyun typecheck(unsigned long, b) && \ 34*4882a593Smuzhiyun ((long)((b) - (a)) < 0)) 35*4882a593Smuzhiyun #define time_before(a,b) time_after(b,a) 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun #define time_after_eq(a,b) \ 38*4882a593Smuzhiyun (typecheck(unsigned long, a) && \ 39*4882a593Smuzhiyun typecheck(unsigned long, b) && \ 40*4882a593Smuzhiyun ((long)((a) - (b)) >= 0)) 41*4882a593Smuzhiyun #define time_before_eq(a,b) time_after_eq(b,a) 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun /* 44*4882a593Smuzhiyun * Calculate whether a is in the range of [b, c]. 45*4882a593Smuzhiyun */ 46*4882a593Smuzhiyun #define time_in_range(a,b,c) \ 47*4882a593Smuzhiyun (time_after_eq(a,b) && \ 48*4882a593Smuzhiyun time_before_eq(a,c)) 49*4882a593Smuzhiyun 50*4882a593Smuzhiyun /* 51*4882a593Smuzhiyun * Calculate whether a is in the range of [b, c). 52*4882a593Smuzhiyun */ 53*4882a593Smuzhiyun #define time_in_range_open(a,b,c) \ 54*4882a593Smuzhiyun (time_after_eq(a,b) && \ 55*4882a593Smuzhiyun time_before(a,c)) 56*4882a593Smuzhiyun 57*4882a593Smuzhiyun #endif /* _TIME_H */ 58