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 #include <linux/types.h>
   8
   9 ulong get_tbclk(void);
  10
  11 unsigned long get_timer(unsigned long base);
  12
  13 /*
  14  * Return the current value of a monotonically increasing microsecond timer.
  15  * Granularity may be larger than 1us if hardware does not support this.
  16  */
  17 unsigned long timer_get_us(void);
  18 uint64_t get_timer_us(uint64_t base);
  19
  20 /**
  21  * get_timer_us_long() - Get the number of elapsed microseconds
  22  *
  23  * This uses 32-bit arithmetic on 32-bit machines, which is enough to handle
  24  * delays of over an hour. For 64-bit machines it uses a 64-bit value.
  25  *
  26  *@base: Base time to consider
  27  *Return: elapsed time since @base
  28  */
  29 unsigned long get_timer_us_long(unsigned long base);
  30
  31 /*
  32  * timer_test_add_offset()
  33  *
  34  * Allow tests to add to the time reported through lib/time.c functions
  35  * offset: number of milliseconds to advance the system time
  36  */
  37 void timer_test_add_offset(unsigned long offset);
  38
  39 /**
  40  * usec_to_tick() - convert microseconds to clock ticks
  41  *
  42  * @usec:       duration in microseconds
  43  * Return:      duration in clock ticks
  44  */
  45 uint64_t usec_to_tick(unsigned long usec);
  46
  47 /*
  48  *      These inlines deal with timer wrapping correctly. You are
  49  *      strongly encouraged to use them
  50  *      1. Because people otherwise forget
  51  *      2. Because if the timer wrap changes in future you won't have to
  52  *         alter your driver code.
  53  *
  54  * time_after(a,b) returns true if the time a is after time b.
  55  *
  56  * Do this with "<0" and ">=0" to only test the sign of the result. A
  57  * good compiler would generate better code (and a really good compiler
  58  * wouldn't care). Gcc is currently neither.
  59  */
  60 #define time_after(a,b)         \
  61         (typecheck(unsigned long, a) && \
  62          typecheck(unsigned long, b) && \
  63          ((long)((b) - (a)) < 0))
  64 #define time_before(a,b)        time_after(b,a)
  65
  66 #define time_after_eq(a,b)      \
  67         (typecheck(unsigned long, a) && \
  68          typecheck(unsigned long, b) && \
  69          ((long)((a) - (b)) >= 0))
  70 #define time_before_eq(a,b)     time_after_eq(b,a)
  71
  72 /*
  73  * Calculate whether a is in the range of [b, c].
  74  */
  75 #define time_in_range(a,b,c) \
  76         (time_after_eq(a,b) && \
  77          time_before_eq(a,c))
  78
  79 /*
  80  * Calculate whether a is in the range of [b, c).
  81  */
  82 #define time_in_range_open(a,b,c) \
  83         (time_after_eq(a,b) && \
  84          time_before(a,c))
  85
  86 /* Same as above, but does so with platform independent 64bit types.
  87  * These must be used when utilizing jiffies_64 (i.e. return value of
  88  * get_jiffies_64() */
  89 #define time_after64(a,b)       \
  90         (typecheck(__u64, a) && \
  91          typecheck(__u64, b) && \
  92          ((__s64)((b) - (a)) < 0))
  93 #define time_before64(a,b)      time_after64(b,a)
  94
  95 #define time_after_eq64(a,b)    \
  96         (typecheck(__u64, a) && \
  97          typecheck(__u64, b) && \
  98          ((__s64)((a) - (b)) >= 0))
  99 #define time_before_eq64(a,b)   time_after_eq64(b,a)
 100
 101 #define time_in_range64(a, b, c) \
 102         (time_after_eq64(a, b) && \
 103          time_before_eq64(a, c))
 104
 105 /**
 106  * usec2ticks() - Convert microseconds to internal ticks
 107  *
 108  * @usec: Value of microseconds to convert
 109  * Return: Corresponding internal ticks value, calculated using get_tbclk()
 110  */
 111 ulong usec2ticks(unsigned long usec);
 112
 113 /**
 114  * ticks2usec() - Convert internal ticks to microseconds
 115  *
 116  * @ticks: Value of ticks to convert
 117  * Return: Corresponding microseconds value, calculated using get_tbclk()
 118  */
 119 ulong ticks2usec(unsigned long ticks);
 120
 121 /**
 122  * wait_ticks() - waits a given number of ticks
 123  *
 124  * This is an internal function typically used to implement udelay() and
 125  * similar. Normally you should use udelay() or mdelay() instead.
 126  *
 127  * @ticks: Number of ticks to wait
 128  */
 129 void wait_ticks(unsigned long ticks);
 130
 131 /**
 132  * timer_get_us() - Get monotonic microsecond timer
 133  *
 134  * Return: value of monotonic microsecond timer
 135  */
 136 unsigned long timer_get_us(void);
 137
 138 /**
 139  * get_ticks() - Get the current tick value
 140  *
 141  * This is an internal value used by the timer on the system. Ticks increase
 142  * monotonically at the rate given by get_tbclk().
 143  *
 144  * Return: current tick value
 145  */
 146 uint64_t get_ticks(void);
 147
 148 #endif /* _TIME_H */