Add a flag SOFT_TIMER_HARD_CALLBACK to request that a soft timer's python
callback is run directly from the IRQ handler with the scheduler and heap
locked, instead of being scheduled via mp_sched_schedule().
Signed-off-by: Chris Webb <chris@arachsys.com>
Progress towards removing pico-sdk alarm pool, due to a known issue.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
If a port defines MICROPY_SOFT_TIMER_TICKS_MS then soft_timer assumes a
SysTick back end, and provides a soft_timer_next variable that sets when
the next call to soft_timer_handler() should occur.
Otherwise, a port should provide soft_timer_get_ms() and
soft_timer_schedule_at_ms() with appropriate semantics (see comments).
Existing users of soft_timer should continue to work as they did.
Signed-off-by: Damien George <damien@micropython.org>
