From 923a7cc505971ab6d04115d18108152f62d46283 Mon Sep 17 00:00:00 2001 From: px4dev Date: Sun, 24 Feb 2013 11:41:26 -0800 Subject: Add an interrupt-safe way of comparing a timestamp with the current time. Add an interrupt-safe way of storing the current time into a timestamp. --- apps/drivers/stm32/drv_hrt.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'apps/drivers/stm32/drv_hrt.c') diff --git a/apps/drivers/stm32/drv_hrt.c b/apps/drivers/stm32/drv_hrt.c index cd9cb45b1..0df2a8b74 100644 --- a/apps/drivers/stm32/drv_hrt.c +++ b/apps/drivers/stm32/drv_hrt.c @@ -645,6 +645,36 @@ abstime_to_ts(struct timespec *ts, hrt_abstime abstime) ts->tv_nsec = abstime * 1000; } +/* + * Compare a time value with the current time. + */ +hrt_abstime +hrt_elapsed_time(const volatile hrt_abstime *then) +{ + irqstate_t flags = irqsave(); + + hrt_abstime delta = hrt_absolute_time() - *then; + + irqrestore(flags); + + return delta; +} + +/* + * Store the absolute time in an interrupt-safe fashion + */ +hrt_absolute_time +hrt_store_absolute_time(volatile hrt_abstime *now) +{ + irqstate_t flags = irqsave(); + + hrt_abstime ts = hrt_absolute_time(); + + irqrestore(flags); + + return ts; +} + /* * Initalise the high-resolution timing module. */ -- cgit v1.2.3