Re: v4l device in userspace

[Pavel Machek <pavel@ucw.cz>]

Hi!

> I've a little program running in the phone, capturing
> images from the camera and sending it to the
> linux box via bluetooth.

Nice!

> Basically I've to pass by the kernel just for
> the interface, and not to do real kernel-side work
> (like to access to the some kind of hardware).
> 
> So I've some questions ( thanks in advance
> for any reply).
> 
> 1) What's the best way to pass relatively
> high-band data between the v4l fake driver
> and userspace? A char device will do the
> work? ioctl?
> 
> 2) What about some way to handle ioctl
> directly from userspace? Given this support
> I may implement the whole code in userspace.
> And I guess there are a lot of other real world
> problems that can be handled in userspace
> given the ability to handle ioctl from there.
> 
> If you think 2) is reasonable I may actually
> implement some simple form of generic
> char driver that just allows userspace
> programs to handle read/write/ioctl
> opreations, and then use this to fix
> my real issue.

You probably want to do something v4l specigic... but generic userspace driver
 able to do read/write/ioctl would be very nice. Lots of devices these days are on usb, and that can be done from userspace, for example.
				Pavel
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