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Implement support for the E-Ink Metronome controller. It provides an mmapable interface to the controller using defio support. It was tested with a gumstix pxa255 with Vizplex media using Xfbdev and various X clients such as xeyes, xpdf, xloadimage. This patch also fixes the following bug: Defio would cause a hang on write access to the framebuffer as the page fault would be called ad-infinitum. It fixes fb_defio by setting the mapping to be used by page_mkclean. Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com> Cc: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
38 lines
2 KiB
Text
38 lines
2 KiB
Text
Metronomefb
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Maintained by Jaya Kumar <jayakumar.lkml.gmail.com>
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Last revised: Nov 20, 2007
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Metronomefb is a driver for the Metronome display controller. The controller
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is from E-Ink Corporation. It is intended to be used to drive the E-Ink
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Vizplex display media. E-Ink hosts some details of this controller and the
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display media here http://www.e-ink.com/products/matrix/metronome.html .
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Metronome is interfaced to the host CPU through the AMLCD interface. The
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host CPU generates the control information and the image in a framebuffer
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which is then delivered to the AMLCD interface by a host specific method.
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Currently, that's implemented for the PXA's LCDC controller. The display and
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error status are each pulled through individual GPIOs.
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Metronomefb was written for the PXA255/gumstix/lyre combination and
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therefore currently has board set specific code in it. If other boards based on
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other architectures are available, then the host specific code can be separated
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and abstracted out.
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Metronomefb requires waveform information which is delivered via the AMLCD
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interface to the metronome controller. The waveform information is expected to
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be delivered from userspace via the firmware class interface. The waveform file
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can be compressed as long as your udev or hotplug script is aware of the need
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to uncompress it before delivering it. metronomefb will ask for waveform.wbf
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which would typically go into /lib/firmware/waveform.wbf depending on your
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udev/hotplug setup. I have only tested with a single waveform file which was
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originally labeled 23P01201_60_WT0107_MTC. I do not know what it stands for.
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Caution should be exercised when manipulating the waveform as there may be
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a possibility that it could have some permanent effects on the display media.
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I neither have access to nor know exactly what the waveform does in terms of
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the physical media.
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Metronomefb uses the deferred IO interface so that it can provide a memory
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mappable frame buffer. It has been tested with tinyx (Xfbdev). It is known
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to work at this time with xeyes, xclock, xloadimage, xpdf.
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