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>
diff --git a/include/time.h b/include/time.h
index e99f9c8..3f00e68 100644
--- a/include/time.h
+++ b/include/time.h
@@ -17,6 +17,17 @@
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()
*