Feature request: Pm1EventRegisterBlock status get and clear

[ChocolateLoverRaj]

From the struct's docs

The register grouping contains two registers - a STS status register that can be read to determine if an event has fired (and written to clear), and an EN enabling register to control whether an event should fire.

Currently the struct has a high level set_event_enabled but no function for getting which events fired and acknowledging / clearing them.

I want to handle the power button in my OS. So far with this library's high level functions I enabled the event and get an interrupt when I press the power button, but I will need to get/clear events.

I will probably make a PR for this.

[martin-hughes]

Good shout - I think there's some room for improvement there. I'm looking forward to seeing what you come up with!

[ChocolateLoverRaj]

I ran into a limitation with MappedGas. PM1 Status Registers are the lower 16 bits of the PM1a_EVT_BLK. Currently MappedGas will see that the PM1a_EVT_BLK register is 32 bits wide and will do 32 bit writes, using write_io_u32. But this would clobber the higher 16 bits. We need a way of writing to just the lower 16 bits. It is allowed here. The spec says

Accesses to the PM1 status registers are done through byte or word accesses..

I will add a function to do it.