The Pirelli DP-L10 phone has a Sunplus SPCA552E chip sitting between the
Calypso baseband processor and the LCD.  The 128x128 pixel CSTN LCD used in
this phone (Giantplus GPM526A0, no datasheet could be found) has a driver chip
(Samsung S6B33B1X) with a built-in framebuffer (display RAM) and presents a
16-bit microprocessor bus interface, hence an LCD of this type could be hooked
up to the Calypso directly, without needing an LCD controller or framebuffer
chip.  Thus the SPCA552E is interposed between the two solely to support the
VGA camera and the associated viewfinder function.

Unfortunately no datasheet could be found for this Sunplus chip.  Instead only
the following two items have been found:

* A Nokia schematic for some completely unrelated phone (not even GSM but CDMA)
  which just happens to have the same SPCA552E chip for its camera function.
  The schematic representation of this chip on page 12 allows us to understand
  the general pinout of this chip, in the absence of a proper datasheet.

* steve-m from OsmocomBB found and used a datasheet for SPCA554A, a much more
  "feature-laden" chip.  Unfortunately the two chips are quite different, and
  the datasheet for the "wrong" chip is of little help for understanding the
  one of interest to us.