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 /**
87  * usec2ticks() - Convert microseconds to internal ticks
88  *
89  * @usec: Value of microseconds to convert
90  * @return Corresponding internal ticks value, calculated using get_tbclk()
91  */
92 ulong usec2ticks(unsigned long usec);
93 
94 /**
95  * ticks2usec() - Convert internal ticks to microseconds
96  *
97  * @ticks: Value of ticks to convert
98  * @return Corresponding microseconds value, calculated using get_tbclk()
99  */
100 ulong ticks2usec(unsigned long ticks);
101 
102 /**
103  * wait_ticks() - waits a given number of ticks
104  *
105  * This is an internal function typically used to implement udelay() and
106  * similar. Normally you should use udelay() or mdelay() instead.
107  *
108  * @ticks: Number of ticks to wait
109  */
110 void wait_ticks(unsigned long ticks);
111 
112 /**
113  * timer_get_us() - Get monotonic microsecond timer
114  *
115  * @return value of monotonic microsecond timer
116  */
117 unsigned long timer_get_us(void);
118 
119 /**
120  * get_ticks() - Get the current tick value
121  *
122  * This is an internal value used by the timer on the system. Ticks increase
123  * monotonically at the rate given by get_tbclk().
124  *
125  * @return current tick value
126  */
127 uint64_t get_ticks(void);
128 
129 #endif /* _TIME_H */
130