mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 17:12:06 +00:00
de7c6d15e3
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>
39 lines
2.0 KiB
Plaintext
39 lines
2.0 KiB
Plaintext
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.
|
|
|