[PATCH/RFC] Change accelerometers to use ABS events rather than REL events.
andy at openmoko.com
Wed Mar 11 08:20:07 CET 2009
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Somebody in the thread at some point said:
|> Either disabling one interrupt or having them both issue the same is a
|> valid solution to A5 situation. On A6, we removed the pullup and have
|> the one interrupt drive push-pull.
| It's not clear to me that 'disabling' is an option.
| The closest seems to be a setting called "GND" which presumably ties
| the line to Ground. Seeing the interrupt is active-low, that would be
| permanently asserted?
You can select it to drive a source that is disabled from ever
happening, obviously it's simpler to just get them to drive the same
source in lockstep.
| For wake-from-suspend we cannot do any tricks with polling. We have
| to choose between wake-on-WUP_FF, or wake-on-CLICK.
| Fortunately there are two accelerometers so we can get all the
| functionality we are likely to want:
Well, there is one more version-and-cpu-related quirk.
On GTA02 A5, the INT1+INT2 net for the second accelerometer ends up on
EINT16 / GPG8. Unfortunately on S3C2442, only EINT0-15 are usable as
On GTA02 A6+, we tried to fix this by bringing a copy of this interrupt
signal to EINT8 / GPG0 which is a wake source. But, we stuck R1547 in
the way which is marked as NC on the schematic version I am looking at.
~ Presumably it really isn't fitted breaking this fix.
So only one accelerometer works for wake.
| When the CPU is running we could take the same approach. Or we could
| conceivably program WUP_FF_2 to have the same threshold as the first
| click threshold. Then when it fires, set a timer for an appropriate
| duration and poll the 'click' status after that duration.
| It might not be worth the effort though.
Not sure if or how the highpass filter can fit in there to allow
threshold to wake on tap or shake.
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