More from the trenches..

If you stop gpsdriver, then restart in the foreground, you can see its messages when the chip is turned on/off
# /etc/init.d/gpsdriver stop
# gpsdriver
gpsdriver is normally started on boot; it creates /dev/pgps and talks to the chip on /dev/ttyS0. It seems to read a binary format from the chip and write NMEA to /dev/pgps.
It saves the almanac in nvd_data.
Nokia Map (navicore) starts navicore-gpsd-helper and gpsd. navicore-gpsd-helper
tells gpsdriver to power up the chip. It also writes gps_last_saved_report when it quits.
gpsd reads NMEA from /dev/pgps and listens on localhost:2947
gpsd runs for as long as there are any clients, then it stops.
navicore and maemo-mapper (and generally any location consumer) read data from
localhost:2947. maemo-mapper 2.4.1 does not start gpsd itself.
My program demo4 both starts and stops the GPS chip via calls to gpsbt_stop(),
gpsbt_start(). navicore-gpsd-helper starts the chip, but does not stop it. If there are
no clients it will time out (30 seconds at least) and turn off, but I believe if there is a client (i.e. gpsd) it will stay on. If the chip is still on a client will get a fix quite rapidly.

This all seems needlessly complicated - four different programs running instead of the
mapper just reading the chip. But the chip format is closed and only one client can
connect to a serial line at one time, while gpsd is an open standard and supports multiple clients...