diff mbox series

[3/6] timer: Allow delays with a 32-bit microsecond timer

Message ID 20200522020223.230834-3-sjg@chromium.org
State Accepted
Commit e1ddf67cb3982b5c49c1165da87917a82a285783
Headers show
Series [1/6] bootstage: Fix 'stacked' typo | expand

Commit Message

Simon Glass May 22, 2020, 2:02 a.m. UTC 
The current get_timer_us() uses 64-bit arithmetic. When implementing
microsecond-level timeouts, 32-bits is plenty. Add a new function to
support this.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 include/time.h | 11 +++++++++++
 lib/time.c     |  5 +++++
 2 files changed, 16 insertions(+)
diff mbox series

Patch

diff --git a/include/time.h b/include/time.h
index e99f9c8012..434e63b075 100644
--- a/include/time.h
+++ b/include/time.h
@@ -17,6 +17,17 @@  unsigned long get_timer(unsigned long base);
 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.
+ *
+ *@base: Base time to consider
+ *@return elapsed time since @base
+ */
+unsigned long get_timer_us_long(unsigned long base);
+
 /*
  * timer_test_add_offset()
  *
diff --git a/lib/time.c b/lib/time.c
index 65db0f6cda..47f8c84327 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -152,6 +152,11 @@  uint64_t __weak get_timer_us(uint64_t base)
 	return tick_to_time_us(get_ticks()) - base;
 }
 
+unsigned long __weak get_timer_us_long(unsigned long base)
+{
+	return timer_get_us() - base;
+}
+
 unsigned long __weak notrace timer_get_us(void)
 {
 	return tick_to_time(get_ticks() * 1000);