Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) Metronomefb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) Maintained by Jaya Kumar <jayakumar.lkml.gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) Last revised: Mar 10, 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) Metronomefb is a driver for the Metronome display controller. The controller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) is from E-Ink Corporation. It is intended to be used to drive the E-Ink
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) Vizplex display media. E-Ink hosts some details of this controller and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) display media here http://www.e-ink.com/products/matrix/metronome.html .
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) Metronome is interfaced to the host CPU through the AMLCD interface. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) host CPU generates the control information and the image in a framebuffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) which is then delivered to the AMLCD interface by a host specific method.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) The display and error status are each pulled through individual GPIOs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) Metronomefb is platform independent and depends on a board specific driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) to do all physical IO work. Currently, an example is implemented for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) PXA board used in the AM-200 EPD devkit. This example is am200epd.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) Metronomefb requires waveform information which is delivered via the AMLCD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) interface to the metronome controller. The waveform information is expected to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) be delivered from userspace via the firmware class interface. The waveform file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) can be compressed as long as your udev or hotplug script is aware of the need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) to uncompress it before delivering it. metronomefb will ask for metronome.wbf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) which would typically go into /lib/firmware/metronome.wbf depending on your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) udev/hotplug setup. I have only tested with a single waveform file which was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) originally labeled 23P01201_60_WT0107_MTC. I do not know what it stands for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) Caution should be exercised when manipulating the waveform as there may be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) a possibility that it could have some permanent effects on the display media.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) I neither have access to nor know exactly what the waveform does in terms of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) the physical media.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) Metronomefb uses the deferred IO interface so that it can provide a memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) mappable frame buffer. It has been tested with tinyx (Xfbdev). It is known
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) to work at this time with xeyes, xclock, xloadimage, xpdf.