Root/Documentation/fb/metronomefb.txt

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

Archive Download this file



interactive