machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the stm32 port for a hard= argument
to explicitly choose between these, setting the default to True to match
the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the esp2 port for a hard= argument
to explicitly choose between these, setting the default to False to match
the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the esp8266 port for a hard= argument
to explicitly choose between these, setting the default to False to match
the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the zephyr port for a hard= argument
to explicitly choose between these, setting the default to False to match
the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the renesas-ra port for a hard= argument
to explicitly choose between these, setting the default to True to match
the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

The Timer initialiser in ports/renesas-ra/timer.c appears to be based on
another port, and options that aren't actually available are listed in
documentation comments and an error message. Correct these.

Signed-off-by: Chris Webb <[email protected]>

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().

Gate support for this flag on MICROPY_SOFT_TIMER_HARD_CALLBACKS so ports
that don't use the softtimer for their machine.Timer() implementation
don't suffer the small code-size increase.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the generic software timer for a hard=
argument to explicitly choose between these, setting the default to False
to match the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the samd port for a hard= argument to
explicitly choose between these. The samd Timer is implemented using the
shared software timer, so define MICROPY_SOFT_TIMER_HARD_CALLBACKS to
enable hard-IRQ support in shared/runtime/softtimer. This automatically
enables the hard= option in extmod/machine_timer, defaulting to False to
match the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the mimxrt port for a hard= argument to
explicitly choose between these. The mimxrt Timer is implemented using the
shared software timer, so define MICROPY_SOFT_TIMER_HARD_CALLBACKS to
enable hard-IRQ support in shared/runtime/softtimer. This automatically
enables the hard= option in extmod/machine_timer, defaulting to False to
match the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

machine.Timer() has inconsistent behaviour between ports: some run
callbacks in hard IRQ context whereas others schedule them like soft IRQs.

As on the rp2 port, add support to the alif port for a hard= argument to
explicitly choose between these. The alif Timer is implemented using the
shared software timer, so define MICROPY_SOFT_TIMER_HARD_CALLBACKS to
enable hard-IRQ support in shared/runtime/softtimer. This automatically
enables the hard= option in extmod/machine_timer, defaulting to False to
match the existing behaviour.

Signed-off-by: Chris Webb <[email protected]>

Now all ports with machine.Timer except nrf support both hard and
soft callbacks, generalise tests/ports/rp2_machine_timer.py into
tests/extmod/machine_timer.py.

There is an existing machine_soft_timer.py which varies period= and
covers the nrf port but skips esp32/esp8266 because they don't support
software timers. In our new test, we try varying freq= instead of period=,
and cover esp32/esp8266 (with a fixed choice of hardware timer) but skip
nrf because it doesn't support hard= or freq=.

Add a check that the heap is locked (so allocation fails) in hard
callbacks and it is unlocked (so allocation succeeds) in soft callbacks,
to ensure we're getting the right kind of callback, not falling back to
the default.

Signed-off-by: Chris Webb <[email protected]>

Update the main machine.Timer specification, and any references to
hard/soft interrupts in port-specific documentation. There is a separate
copy of the machine.Timer documentation for the pyboard, so update that
too to keep everything consistent.

Signed-off-by: Chris Webb <[email protected]>