[U-Boot] [PATCH] lib: time: Add microsecond timer

[Marek Vasut]

Add get_timer_us(), which is useful e.g. when we need higher
precision timestamps.

Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
Cc: Tom Rini <trini at konsulko.com>
Cc: Simon Glass <sjg at chromium.org>
---
 include/time.h |  1 +
 lib/time.c     | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/include/time.h b/include/time.h
index 1e9b369be7..a1149522ed 100644
--- a/include/time.h
+++ b/include/time.h
@@ -13,6 +13,7 @@ unsigned long get_timer(unsigned long base);
  * 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);
 
 /*
  * timer_test_add_offset()
diff --git a/lib/time.c b/lib/time.c
index f5751ab162..f30fc05804 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -134,6 +134,20 @@ ulong __weak get_timer(ulong base)
 	return tick_to_time(get_ticks()) - base;
 }
 
+static uint64_t notrace tick_to_time_us(uint64_t tick)
+{
+	ulong div = get_tbclk() / 1000;
+
+	tick *= CONFIG_SYS_HZ;
+	do_div(tick, div);
+	return tick;
+}
+
+uint64_t __weak get_timer_us(uint64_t base)
+{
+	return tick_to_time_us(get_ticks()) - base;
+}
+
 unsigned long __weak notrace timer_get_us(void)
 {
 	return tick_to_time(get_ticks() * 1000);
-- 
2.23.0