ARMv7-A cores can implement the optional 64bit wide generic timer
CNTPCT[1]. If it is present we can use it to implement the get_time_ns
and is_timeout helpers which in turn enable the whole read_poll_timeout
class of functions in the PBL. As it is guaranteed that the timer won't
wrap for 40 years no overflow handling is necessary.
[1]: See "ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition
(rev C.d)", Chapter B8 "The Generic Timer"
Signed-off-by: Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx>
---
arch/arm/lib32/arm_architected_timer.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm/lib32/arm_architected_timer.c b/arch/arm/lib32/arm_architected_timer.c
index 54eca13f8b9d1c940d54f0e34c1dd261c5eec8c7..75f74cbc15ccf09b2fae1fc287138118c3c3c22c 100644
--- a/arch/arm/lib32/arm_architected_timer.c
+++ b/arch/arm/lib32/arm_architected_timer.c
@@ -10,8 +10,21 @@ void arm_architected_timer_udelay(unsigned long us)
unsigned long long ticks, cntfrq = get_cntfrq();
unsigned long long start = get_cntpct();
- ticks = DIV_ROUND_DOWN_ULL((us * cntfrq), 1000000);
+ ticks = DIV_ROUND_DOWN_ULL((us * cntfrq), MSECOND);
while ((long)(start + ticks - get_cntpct()) > 0)
;
}
+
+uint64_t get_time_ns(void)
+{
+ return get_cntpct() * SECOND / get_cntfrq();
+}
+
+int is_timeout(uint64_t start, uint64_t time_offset_ns)
+{
+ if ((int64_t)(start + time_offset_ns - get_time_ns()) < 0)
+ return 1;
+ else
+ return 0;
+}
--
2.39.5
