/*
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef _TIME_H
  #define _TIME_H

  #include <linux/typecheck.h>

  unsigned long get_timer(unsigned long base);
  
  /*
   * Return the current value of a monotonically increasing microsecond timer.
   * Granularity may be larger than 1us if hardware does not support this.
   */
  unsigned long timer_get_us(void);

  /*
   *	These inlines deal with timer wrapping correctly. You are
   *	strongly encouraged to use them
   *	1. Because people otherwise forget
   *	2. Because if the timer wrap changes in future you won't have to
   *	   alter your driver code.
   *
   * time_after(a,b) returns true if the time a is after time b.
   *
   * Do this with "<0" and ">=0" to only test the sign of the result. A
   * good compiler would generate better code (and a really good compiler
   * wouldn't care). Gcc is currently neither.
   */
  #define time_after(a,b)		\
  	(typecheck(unsigned long, a) && \
  	 typecheck(unsigned long, b) && \
  	 ((long)((b) - (a)) < 0))
  #define time_before(a,b)	time_after(b,a)
  
  #define time_after_eq(a,b)	\
  	(typecheck(unsigned long, a) && \
  	 typecheck(unsigned long, b) && \
  	 ((long)((a) - (b)) >= 0))
  #define time_before_eq(a,b)	time_after_eq(b,a)
  
  /*
   * Calculate whether a is in the range of [b, c].
   */
  #define time_in_range(a,b,c) \
  	(time_after_eq(a,b) && \
  	 time_before_eq(a,c))
  
  /*
   * Calculate whether a is in the range of [b, c).
   */
  #define time_in_range_open(a,b,c) \
  	(time_after_eq(a,b) && \
  	 time_before(a,c))

  #endif /* _TIME_H */