I'm a Linux enthusiast / developer. Lately I'm mainly active doing
development for Fedora and writing kernel drivers (and as my day job I'm a
lecturer in Computer Science).
Fedora has a policy of not shipping a heavily patched kernel, but instead
tries to work with upstream to get any needed patches integrated. This
policy extends to not shipping any addon drivers, but rather working to get
drivers integrated upstream.
As such I've decided to start spending my spare time on getting more and
better usb webcam support integrated upstream (for non usb video class
devices). I wanted to have something to show, so I've gone to the store,
bought a couple of webcams and started hacking and learning.
2 days ago I have finished my first pretty clean, standalone v4l2 webcam
driver for Pixart pac207 webcams.
In the beginning I modelled this driver after the zc301 and sn9c102 driver
which are currently already in the mainline kernel, using the memory
management and other structure from these drivers and filling in the
hardware dependent parts with the pac207 code from the out of tree gpsca
During the development I kept the buffer management from the zc301 driver,
but modelled the rest of the driver more and more after gspca. For example
don't start the iso stream on device open and throw away iso packets
received before the stream-on ioctl, but instead start and stop the stream
This has resulted in what I consider a nice and clean pac207 driver. But
when I finished it I noticed that a lot of code in their was generic code
for any simple usb webcam.
Since I plan to write standalone v4l2 drivers for mainline inclusion for
other simple usb webcams I spend the last 2 days splitting the code of my
pac207 driver into a generic usbvideo2 core (the kernel already has
usbvideo, which has a number of v4l1 drivers) and a camera specific pac207
driver which builds on top of the usbvideo2 core.
So I've ended up with a model very much like gspca, but then not one large
monolithic kernel module, but a more modular design with an core kernel
module with (hopefully) generic code for simple usb webcam's, and a per usb
controller chip type specific module (currently only one for pac207
controllers), and ofcourse very important this is code for v4l2 drivers,
whereas the current gspca is v4l1.
I just recently (today) learned that there is work underway to make a v4l2
version of gspca by Jean-François Moine: http://moinejf.free.fr/
), I hope
that we can work together somehow on getting support for all the webcam's
supported in gscpa integrated into the mainline kernel with a v4l2
I'll be sending 2 seperate mails one with my standalone pac207 driver, and
one with the usbvideo2 core and a pac207 driver using this core, I'll
include Makefiles for out of tree building with both of them so that
interested people can test them.
I'm currently posting these as .c files for easy reading and compilation /
testing, but I still hope to get a lot of feedback / a thorough review, esp
of the core <-> pac207 split version as I hope to submit that as a patch
for mainline inclusion soon.
Thanks & Regards,
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Spca50x-devs mailing list
I don't understand why you start this work without asking the gspca
maintener ? Jean-Francois is working on the gspca_core driver for v4l2, you
should help if you want.The pac207 maintener is Thomas, feel free to contact
the spca50x-devel mailing list.
If you have times you can try to implement the sn9c201 sn9c202 from Sonix,
there is only a proprietary driver available at the moment ;-)