Droid 4 devices have mxt224 touchscreen controller with firwmare for it
stored into the Motorola Linux kernel source tree as a binary licensed
under GPLv2.

This program allows generating the maxtouch.fw file out of the header
file and it seems that file can be uploaded to the mxt224 via sysfs if
somebody wants to attempt to it. I've only done it once and it seemed to
still work after that. To do that, the firmware needs to be placed under
/lib/firmware/maxtouch.fw and uploaded to the mxt224 device by doing:

# echo 1 > /sys/.../i2c-1/1-004a/update_fw

See also "mxt-app" program that can be used to save the maxtouch.cfg
with:

# mxt-app -d i2c-dev:1-004a --save /lib/firmware/maxtouch.cfg

The "mxt-app" program can be found at:

https://github.com/atmel-maxtouch/mxt-app