we really need set_retries() high during init for nearly all i2c
devices, and as many are written against the generic device class
moving it to the Device class makes this a lot easier. It is a NOP on
SPI.
Replace the previous not-implemented interface with a set of new methods
that can be resonably implemented:
- register_periodic_callback() now receives a functor returning bool
to easily allow "oneshot" timers
- adjust_periodic_callback() allows the caller to change the timer
for a specific handle. This way drivers like MS5611 can adjust the
timer depending on its state machine: the time to sample
temperature is smaller than the time to get a pressure sample
- add unregister_callback(): since we have an opaque pointer, we
can't tell the user to just delete it in order to unregister the
callback
Lucas De Marchi
Andrew Tridgell
Mathieu OTHACEHE
Gustavo Jose de Sousa