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 <[email protected]> --- 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 54eca13f8b..75f74cbc15 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; +} -- 2.47.3
