metronomefb.rst (2006B)
1=========== 2Metronomefb 3=========== 4 5Maintained by Jaya Kumar <jayakumar.lkml.gmail.com> 6 7Last revised: Mar 10, 2008 8 9Metronomefb is a driver for the Metronome display controller. The controller 10is from E-Ink Corporation. It is intended to be used to drive the E-Ink 11Vizplex display media. E-Ink hosts some details of this controller and the 12display media here http://www.e-ink.com/products/matrix/metronome.html . 13 14Metronome is interfaced to the host CPU through the AMLCD interface. The 15host CPU generates the control information and the image in a framebuffer 16which is then delivered to the AMLCD interface by a host specific method. 17The display and error status are each pulled through individual GPIOs. 18 19Metronomefb is platform independent and depends on a board specific driver 20to do all physical IO work. Currently, an example is implemented for the 21PXA board used in the AM-200 EPD devkit. This example is am200epd.c 22 23Metronomefb requires waveform information which is delivered via the AMLCD 24interface to the metronome controller. The waveform information is expected to 25be delivered from userspace via the firmware class interface. The waveform file 26can be compressed as long as your udev or hotplug script is aware of the need 27to uncompress it before delivering it. metronomefb will ask for metronome.wbf 28which would typically go into /lib/firmware/metronome.wbf depending on your 29udev/hotplug setup. I have only tested with a single waveform file which was 30originally labeled 23P01201_60_WT0107_MTC. I do not know what it stands for. 31Caution should be exercised when manipulating the waveform as there may be 32a possibility that it could have some permanent effects on the display media. 33I neither have access to nor know exactly what the waveform does in terms of 34the physical media. 35 36Metronomefb uses the deferred IO interface so that it can provide a memory 37mappable frame buffer. It has been tested with tinyx (Xfbdev). It is known 38to work at this time with xeyes, xclock, xloadimage, xpdf.