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Diffstat (limited to 'Documentation/fb/metronomefb.txt')
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diff --git a/Documentation/fb/metronomefb.txt b/Documentation/fb/metronomefb.txt new file mode 100644 index 000000000000..b9a2e7b7e838 --- /dev/null +++ b/Documentation/fb/metronomefb.txt @@ -0,0 +1,38 @@ + Metronomefb + ----------- +Maintained by Jaya Kumar <jayakumar.lkml.gmail.com> +Last revised: Nov 20, 2007 + +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. +Currently, that's implemented for the PXA's LCDC controller. The display and +error status are each pulled through individual GPIOs. + +Metronomefb was written for the PXA255/gumstix/lyre combination and +therefore currently has board set specific code in it. If other boards based on +other architectures are available, then the host specific code can be separated +and abstracted out. + +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 waveform.wbf +which would typically go into /lib/firmware/waveform.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. + |