u-boot/include/time.h
Simon Glass e1ddf67cb3 timer: Allow delays with a 32-bit microsecond timer
The current get_timer_us() uses 64-bit arithmetic on 32-bit machines.
When implementing microsecond-level timeouts, 32-bits is plenty. Add a
new function that uses an unsigned long. On 64-bit machines this is
still 64-bit, but this doesn't introduce a penalty. On 32-bit machines
it is more efficient.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00

129 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef _TIME_H
#define _TIME_H
#include <linux/typecheck.h>
#include <linux/types.h>
ulong get_tbclk(void);
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);
uint64_t get_timer_us(uint64_t base);
/**
* get_timer_us_long() - Get the number of elapsed microseconds
*
* This uses 32-bit arithmetic on 32-bit machines, which is enough to handle
* delays of over an hour. For 64-bit machines it uses a 64-bit value.
*
*@base: Base time to consider
*@return elapsed time since @base
*/
unsigned long get_timer_us_long(unsigned long base);
/*
* timer_test_add_offset()
*
* Allow tests to add to the time reported through lib/time.c functions
* offset: number of milliseconds to advance the system time
*/
void timer_test_add_offset(unsigned long offset);
/**
* usec_to_tick() - convert microseconds to clock ticks
*
* @usec: duration in microseconds
* Return: duration in clock ticks
*/
uint64_t usec_to_tick(unsigned long usec);
/*
* 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))
/**
* usec2ticks() - Convert microseconds to internal ticks
*
* @usec: Value of microseconds to convert
* @return Corresponding internal ticks value, calculated using get_tbclk()
*/
ulong usec2ticks(unsigned long usec);
/**
* ticks2usec() - Convert internal ticks to microseconds
*
* @ticks: Value of ticks to convert
* @return Corresponding microseconds value, calculated using get_tbclk()
*/
ulong ticks2usec(unsigned long ticks);
/**
* wait_ticks() - waits a given number of ticks
*
* This is an internal function typically used to implement udelay() and
* similar. Normally you should use udelay() or mdelay() instead.
*
* @ticks: Number of ticks to wait
*/
void wait_ticks(unsigned long ticks);
/**
* timer_get_us() - Get monotonic microsecond timer
*
* @return value of monotonic microsecond timer
*/
unsigned long timer_get_us(void);
/**
* get_ticks() - Get the current tick value
*
* This is an internal value used by the timer on the system. Ticks increase
* monotonically at the rate given by get_tbclk().
*
* @return current tick value
*/
uint64_t get_ticks(void);
#endif /* _TIME_H */