include/time.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #ifndef _TIME_H
   4 #define _TIME_H
   5
   6 #include <linux/typecheck.h>
   7
   8 unsigned long get_timer(unsigned long base);
   9
  10 /*
  11  * Return the current value of a monotonically increasing microsecond timer.
  12  * Granularity may be larger than 1us if hardware does not support this.
  13  */
  14 unsigned long timer_get_us(void);
  15
  16 /*
  17  * timer_test_add_offset()
  18  *
  19  * Allow tests to add to the time reported through lib/time.c functions
  20  * offset: number of milliseconds to advance the system time
  21  */
  22 void timer_test_add_offset(unsigned long offset);
  23
  24 /*
  25  *      These inlines deal with timer wrapping correctly. You are
  26  *      strongly encouraged to use them
  27  *      1. Because people otherwise forget
  28  *      2. Because if the timer wrap changes in future you won't have to
  29  *         alter your driver code.
  30  *
  31  * time_after(a,b) returns true if the time a is after time b.
  32  *
  33  * Do this with "<0" and ">=0" to only test the sign of the result. A
  34  * good compiler would generate better code (and a really good compiler
  35  * wouldn't care). Gcc is currently neither.
  36  */
  37 #define time_after(a,b)         \
  38         (typecheck(unsigned long, a) && \
  39          typecheck(unsigned long, b) && \
  40          ((long)((b) - (a)) < 0))
  41 #define time_before(a,b)        time_after(b,a)
  42
  43 #define time_after_eq(a,b)      \
  44         (typecheck(unsigned long, a) && \
  45          typecheck(unsigned long, b) && \
  46          ((long)((a) - (b)) >= 0))
  47 #define time_before_eq(a,b)     time_after_eq(b,a)
  48
  49 /*
  50  * Calculate whether a is in the range of [b, c].
  51  */
  52 #define time_in_range(a,b,c) \
  53         (time_after_eq(a,b) && \
  54          time_before_eq(a,c))
  55
  56 /*
  57  * Calculate whether a is in the range of [b, c).
  58  */
  59 #define time_in_range_open(a,b,c) \
  60         (time_after_eq(a,b) && \
  61          time_before(a,c))
  62
  63 #endif /* _TIME_H */