[gpsd-dev] Initialization & probing questions

[Kai Harrekilde-Petersen]

Hello all,

I'm trying to implement the Skytraq driver the 'right way', going by the 
comments in driver_proto.c and referencing the Ublox driver.

I have a couple of questions that is may be obvious to those that know 
the design well, but isn't clear to me:

1) If I send a command, how should I wait for the response before returning?
For example, when I'm in _proto__event_hook() with event == 
event_identified, I can probe for the firmware version, but getting the 
response back is going to take a while. Similar, when in 
_proto__probe_detect() and _proto__init_query(), I need to wait for a 
response to be returned before returning to the caller.
- Will a nanosleep() for "an appropriate time" do?

2) .trigger()
It doesn't seem to much used - should I bother with it?

3) Excessive probing time.
Since the Skytraq powers up at 115.200 baud, it takes an obscene amount 
of time for it to be probed (as  584 sec. Yes, almost 10 min!).
Is there a simple way (at least during development) to cut this down to 
something more reasonable? - it seems like that it always starts out a 
4800/9600 baud, and going up in baudrate. I tried messing with serial.c 
and (trying to) disable a lot of the other GPS drivers, but I didn't 
have any luck with either.

4) Store/restore of device settings.
The skytraq allows to to probe its settings to hearts' content, which 
allows me to restore the state when deactivating.
Not many drivers even detect event_deactivate being fired. Should I bother?

Thanks,

Kai
--
Kai Harrekilde-Petersen