Re: working on webcam driver

2009-05-14 Thread MK
Since I'm cross-posting this (as advised) I should introduce myself by 
saying I am a neophyte C programmer getting into kernel programming by 
trying to write a driver for an unsupported webcam.  So far I've gotten 
the device to register and have enumerated the various interfaces.

On 05/11/2009 02:50:00 PM, Erik Andrén wrote:
First of all, this list is deprecated. Send mails to if you want to reach the kernel community.

 Secondly, have you researched that there is no existing driver for
 your camera? A good way to start would perhaps to search for the usb
 id and linux in google to see if it generates some hits.

I've done this last bit already, and I just checked out gspca.  There 
is a lot of listing for the vendor id, but not the product id, so I 
imagine there is no point in trying any of the drivers (unless I hack 
the source to accept the id string).

However, a rather unhelpful person at the linux driver backport group 
informs me not all USB video drivers are under
drivers/media/video/usbvideo/  In fact, the majority of them are not. 
but then tells me I should take off and go find them myself with a web 
browser (very nice).  

Does anyone know where these drivers are located?  The same person also 
claims that the kernel now has support for all devices that 
follow the USB video class specification, and [sic] that the additional 
23 device specific drivers in the tree* are just for non-conforming 
devices.  This kind of flies in the face of everything else I have 
read about linux and usb webcams.  I also notice that it is impossible 
to select anything other than the v4l layer with xconfig, ie. the 
individual drivers cannot be selected.

Is it normal to include module sources in the tree without making it 
possible to configure them into a regular build?

Sincerely, Mark Eriksen

*I can only find the six under drivers/media, and nothing in 
documentation/ is of assistance

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Re: working on webcam driver

2009-05-17 Thread MK
Thanks much for the feedback!  Here's what happened:

Because the vendor id (0c45) is listed by the gspca website but not 
the product (612a), I decided to try inserting the id into one of the 
drivers/media/video/gspca.  When I actually grepped (had not grepped 
the tree itself yet), low and behold 612a is in sonixj.  The module 
compiles and responds to the camera, although the results in gstreamer, 
et. al, are disappointing -- the camera is not really usable, I suspect 
from the output it is the kernel driver, but I am not sure.  Since I 
didn't write this stuff, I think working alone it will be more trouble 
than it is worth to track the problem down, esp. if this is mostly a 
problem with an (obscure) inexpensive item that few linux users 
actually possess.

So, I am going to cut my loses early on this project and cop out.  
I've learned a bunch about the kernel and in the process written some 
nifty little char drivers that are probably more useful to me than a 
webcam anyway. I think my time would be better spent on other things, 
eg, I might become useful in someone else's (more significant) linux 
kernel/driver project.  I will have a look around.

But thanks again!  You were much nicer than mr Greg Kroah-Hartman ;) :0

Sincerely, Mark Eriksen (getting his feet wet)

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