Refactor old Watchdog (it was not a driver) to become VirtualWatchdog.
This is software virtual watchdog. This it the primary used watchdog in user application.
VirtualWatchdog: has-a watchdog. Initializes hw watchdog - start it when first used, stops it when there is no more VirtualWatchdog in the system -
list is empty.
Adding also check to watchdog to make sure there is only one in the system - runtime error if multiple objects created to already
running hw watchdog.
Watchdog is hardware driver. It interacts with HAL - provides wrapper to interact with the peripheral.
Provides basic functionality: start/stop, get timeout/max timeout.
It is automatically kicked by a timer, according to the timeout set in ctor.
For L0/L4/H7/F7/WB targets that have tickless enabled, remove the tickless from
us ticker and the delay ticks as the C++ wrapper layer is being removed
and replaced by the low layer handling.
For now, the few F4 targets with LPTIM are left with previous configuration
as test results are showing a few instabilities not yet understood.
LP TICKER mbed-os wrapper needs to be disabled as it introduces too much latencies.
LP TICKER wrapper has been disabled and we need to managed the HW constraints at low level:
- main HW constraint is that once the comparator has been programmed once,
driver cannot program it again before CMPOK HW flag is set, which takes about 3 30us cycles.
To make it even more complex, the driver also needs to cope with "LP ticker workaround"
See commit:
LP ticker workaround
There is an errata in LPTIM specification that explains that CMP Flag
condition is not an exact match (COUNTER = MATCH) but rather a
comparison (COUNTER >= MATCH).
Also the disable interrupt is more complete now:
- always check sleep manager status and restore it
- remove irq_handler as comparator is always programed and might get called
eventually when LP TICK is restarted
- reset delayed_prog
Also in set_interrupt, make sure interrupt does not fire early.
If needed, we decide to slightly delay the tick to cope with the HW limitation to
make sure it will fire as soon as HW is capable.
Functions are called under critical section as they may be called from
the IRQ handler now, not only from driver layer.
There is an errata in LPTIM specification that explains that CMP Flag
condition is not an exact match (COUNTER = MATCH) but rather a
comparison (COUNTER >= MATCH).
As a consequence the interrupt is firing early than expected when
programing a timestamp after the 0xFFFF wrap-around.
In order to
work-around this issue, we implement the below work-around.
In case timestamp is after the work-around, let's decide to program the
CMP value to 0xFFFF, which is the wrap-around value. There would anyway be
a wake-up at the time of wrap-around to let the OS update the system time.
When the wrap-around interrupt happen, OS will check the current time and
program again the timestamp to the proper value.
Port the cc310 SHA512 driver, even though it is sw implementation.
Because the linker could not remove the cc310 sha512 implementation,
there was duplicate implementation of SHA512, without enabling
the sha512 alternative implementation.
Martin Kojtal
Evelyne Donnaes
Antti Kauppila
George Beckstein
Tymoteusz Bloch
Philipp Steiner
Ron Eldor
Kevin Bracey
Laurent Meunier
Mahesh Mahadevan
jeromecoutant