The knowledge that lp_ticker runs in deep sleep was hard-coded with a
comparison check of a ticker_data_t pointer against get_lp_ticker_data.
Remove this hard-coded check, which adds a linker dependency against
the low power ticker even if not being used - put a flag into the
ticker_interface_t.
A future extension might be to move this flag into the ticker_info_t
provided by the HAL, but for the moment keep the assumption that
lp_ticker does run, us_ticker doesn't.
Wait until dispatching is finished before scheduling the next ticker
interrupt. This prevents unnecissary calls to set_interrupt from
periodic elements being added back.
This is particularly useful for the low power ticker on devices with
LPTICKER_DELAY_TICKS set to a non-zero value. This is because the low
power ticker cannot be reschduled immediately and needs to fall back
onto the microsecond ticker which temporarily locks deep sleep.
Allow tickers to specify their native frequency and number of bits.
This allows the conversion to happen in common code rather than in
each vendor's implementation.
fire_interrupt function should be used for events in the past. As we have now
64bit timestamp, we can figure out what is in the past, and ask a target to invoke
an interrupt immediately. The previous attemps in the target HAL tickers were not ideal, as it can wrap around easily (16 or 32 bit counters). This new
functionality should solve this problem.
set_interrupt for tickers in HAL code should not handle anything but the next match interrupt. If it was in the past is handled by the upper layer.
It is possible that we are setting next event to the close future, so once it is set it is already in the past. Therefore we add a check after set interrupt to verify it is in future.
If it is not, we fire interrupt immediately. This results in
two events - first one immediate, correct one. The second one might be scheduled in far future (almost entire ticker range),
that should be discarded.
The specification for the fire_interrupts are:
- should set pending bit for the ticker interrupt (as soon as possible),
the event we are scheduling is already in the past, and we do not want to skip
any events
- no arguments are provided, neither return value, not needed
- ticker should be initialized prior calling this function (no need to check if it is already initialized)
All our targets provide this new functionality, removing old misleading if (timestamp is in the past) checks.
- A new 64 timestamp type has been added: us_timestamp_t.
- Changed type of timestamp in ticker_events iinto us_timestamp_t.
- Event queue now have a to store a current, absolute timestamp.
- Add alternative versions of ticker_insert_event and ticker_read which accept
in input us_timestamp_t.
- Add documentation explaining the limitation and behavior of ticker_read and
ticker_insert_event.
Kevin Bracey
Martin Kojtal
Russ Butler
Cruz Monrreal
Przemyslaw Stekiel
Marc Emmers
Jimmy Brisson
Filip Jagodzinski
Martin Kojtal
Kevin Gilbert
Vincent Coubard
Christopher Haster