NOTES

Power management
===========================================================================

From http://wiki.openmoko.org/wiki/Getting_Started_with_your_Neo1973#Suspending
"Writing "mem" into /sys/power/state tells Linux to suspend - it will
enter a low power mode where only the GSM and RAM are powered up and
the CPU sleeps. It will persist in this state until a wake-up event
arrives. Some currently enabled wake-up events are: AUX or POWER key
press, USB cable detect."


http://wiki.openmoko.org/wiki/Neo1973_GTA01_Power_Management


http://wiki.openmoko.org/wiki/GTA01_gsm_modem

AT@POFF must be sent to the modem before using the /sys/... interface
to "turn off power" to the modem.

To avoid infinite echo during GSM modem power-on, use
  stty -F /dev/ttySAC0 -echo
before
  echo "1" >/sys/bus/platform/devices/gta01-pm-gsm.0/power_on

Similarly, to avoid kernel lock-ups, disable CRTSCTS before powering
off the modem:
  stty -F /dev/ttySAC0 -crtscts
  echo "0" >/sys/bus/platform/devices/gta01-pm-gsm.0/power_on

When suspended, don't AT@POFF, but do 0>power_on. Make sure CTS is
off. An interrupt will be generated to wake the CPU. -- this is
probably already done as part of writing "mem" to /sys/power/state??