projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| de7c6d15 JK |
1 | Metronomefb |
| 2 | ----------- | |
| 3 | Maintained by Jaya Kumar <jayakumar.lkml.gmail.com> | |
| 4 | Last revised: Nov 20, 2007 | |
| 5 | ||
| 6 | Metronomefb is a driver for the Metronome display controller. The controller | |
| 7 | is from E-Ink Corporation. It is intended to be used to drive the E-Ink | |
| 8 | Vizplex display media. E-Ink hosts some details of this controller and the | |
| 9 | display media here http://www.e-ink.com/products/matrix/metronome.html . | |
| 10 | ||
| 11 | Metronome is interfaced to the host CPU through the AMLCD interface. The | |
| 12 | host CPU generates the control information and the image in a framebuffer | |
| 13 | which is then delivered to the AMLCD interface by a host specific method. | |
| 14 | Currently, that's implemented for the PXA's LCDC controller. The display and | |
| 15 | error status are each pulled through individual GPIOs. | |
| 16 | ||
| 17 | Metronomefb was written for the PXA255/gumstix/lyre combination and | |
| 18 | therefore currently has board set specific code in it. If other boards based on | |
| 19 | other architectures are available, then the host specific code can be separated | |
| 20 | and abstracted out. | |
| 21 | ||
| 22 | Metronomefb requires waveform information which is delivered via the AMLCD | |
| 23 | interface to the metronome controller. The waveform information is expected to | |
| 24 | be delivered from userspace via the firmware class interface. The waveform file | |
| 25 | can be compressed as long as your udev or hotplug script is aware of the need | |
| 26 | to uncompress it before delivering it. metronomefb will ask for waveform.wbf | |
| 27 | which would typically go into /lib/firmware/waveform.wbf depending on your | |
| 28 | udev/hotplug setup. I have only tested with a single waveform file which was | |
| 29 | originally labeled 23P01201_60_WT0107_MTC. I do not know what it stands for. | |
| 30 | Caution should be exercised when manipulating the waveform as there may be | |
| 31 | a possibility that it could have some permanent effects on the display media. | |
| 32 | I neither have access to nor know exactly what the waveform does in terms of | |
| 33 | the physical media. | |
| 34 | ||
| 35 | Metronomefb uses the deferred IO interface so that it can provide a memory | |
| 36 | mappable frame buffer. It has been tested with tinyx (Xfbdev). It is known | |
| 37 | to work at this time with xeyes, xclock, xloadimage, xpdf. | |
| 38 |