|Maintained by Jaya Kumar <jayakumar.lkml.gmail.com>
|Last revised: Mar 10, 2008
|Metronomefb is a driver for the Metronome display controller. The controller
|is from E-Ink Corporation. It is intended to be used to drive the E-Ink
|Vizplex display media. E-Ink hosts some details of this controller and the
|display media here http://www.e-ink.com/products/matrix/metronome.html .
|Metronome is interfaced to the host CPU through the AMLCD interface. The
|host CPU generates the control information and the image in a framebuffer
|which is then delivered to the AMLCD interface by a host specific method.
|The display and error status are each pulled through individual GPIOs.
|Metronomefb is platform independent and depends on a board specific driver
|to do all physical IO work. Currently, an example is implemented for the
|PXA board used in the AM-200 EPD devkit. This example is am200epd.c
|Metronomefb requires waveform information which is delivered via the AMLCD
|interface to the metronome controller. The waveform information is expected to
|be delivered from userspace via the firmware class interface. The waveform file
|can be compressed as long as your udev or hotplug script is aware of the need
|to uncompress it before delivering it. metronomefb will ask for metronome.wbf
|which would typically go into /lib/firmware/metronome.wbf depending on your
|udev/hotplug setup. I have only tested with a single waveform file which was
|originally labeled 23P01201_60_WT0107_MTC. I do not know what it stands for.
|Caution should be exercised when manipulating the waveform as there may be
|a possibility that it could have some permanent effects on the display media.
|I neither have access to nor know exactly what the waveform does in terms of
|the physical media.
|Metronomefb uses the deferred IO interface so that it can provide a memory
|mappable frame buffer. It has been tested with tinyx (Xfbdev). It is known
|to work at this time with xeyes, xclock, xloadimage, xpdf.