linux drivers for Linksys CIT200?

[Peepsalot]

Does anyone think it would be feasible/worthwhile to start a project to create Linux drivers for this device?
The Linksys CIT200 is a wireless phone for use with skype. The base station interfaces with your computer via USB. Linksys does not offer Linux drivers, so I thought of trying to make my own.

Is anyone interested in working on this project?
Has anyone here developed USB device drivers for linux before?

I have a college degree in computer science, and have spent the last 4 years working as a web application developer, but have no experience in writing Linux device drivers. I think it would be great to work on something like this, but I'm not even sure if this sort of project is just too complex to be feasible.

Here are some basic links I've looked over so far.
http://www.linuxjournal.com/article/7353
http://www.linuxjournal.com/article/4786
http://sourceforge.net/projects/usbsnoop/
http://www.usb.org/developers/docs.html

I have run USB Snoopy on the device already and found that it uses 3 different USB drivers!
USB Composite Device
USB Audio Device
USB Human Interface Device

I made a log file, but not sure how to decipher it yet.

[froggontherocks]

I would very much like to see the driver written but unfortunately I don't have any experience writing drivers either. But wanted to throw in my 2 cents that there should be one.

[viczh]

You don't need to write a driver - CIT200 is a composite, comprised of two devices - isochronous phone/mic and HID. They are well known devices and can be accessed without drivers - there are class drivers for them already. CIT200 Windows app does not install any drivers (AFAIK) - they use this combination.

[Peepsalot]

Well, that is good news. So do you know how I can make use of this phone with skype then?

In my skype configurations for Audio devices, I can see the CIT 200 and I have selected for audio in, audio out, and ringing.

But the handset display always says "DISCONNECTED" when plugged into my Linux box. So this is were I'm assuming I have a driver deficiency. In windows it would either say "SKYPE OFFLINE" or "CONNECTED" depending on whether the Skype application was running at the time. I have never seen it say "DISCONNECTED" in Windows. If I completely disconnect the USB cable for the base, the handset will say "SEARCH BASE".

So I can't dial from the handset because it is not speaking to the program. In windows, the phone would load my list of contacts from the application, but in Linux I don't see anything.
If I dial from the skype program, I get no sound.

Here is what i get in dmesg when I connect the USB cable.

[17188923.272000] ohci_hcd 0000:00:02.1: wakeup
[17188923.656000] usb 2-3: new full speed USB device using ohci_hcd and address 11
[17188923.904000] usb 2-3: configuration #1 chosen from 1 choice
[17188925.412000] hiddev96: USB HID v1.01 Device [LINKSYS Linksys CIT200] on usb-0000:00:02.1-3

I don't see it saying anything about the audio device, but then how does skype know it exists?

[Peepsalot]

bump

[viczh]

It generally works like this:

It is composite device consisting of two devices: HID and audio. HID is a device for which you don't have to have a driver but this does not help - you still need to understand protocol, that is sets of messages this device exchanges with the application program. There are messages for setting time (have you noticed that it shows time, set on your computer), to pass a number you dialing, to fill out address book, and to turn on or off mic/phone combination. By default they are turned off physically, that is why you can not hear your computer sounds, but if you call someone and play some sound, you must hear this through your handset.

So beyond being recognized and connected by your USB HID and audio subsystems the device should be guided through all stages of phone call - dialing, waiting, connection or busy signal, disconnection. The program handling it, polls device every 10ms and if you stop polling, device mentions it pretty soon.

This same controlling program rules Skype through its official API - it tells it what number to dial, recognizes waiting signal callback and as soon as the other party answers, it turns on the device's mike and phone.

So it is still some work ahead on deciphering the meaning of device messages.

[shoki]

Has this been solved? This is the only issue (no CIT200 wireless phone for skype) keeping my wife away from ubuntu. If I can get this to work I can go 100% ubuntu desktop at home!

[bagguley]

Also the only thing keeping me from being a Windows free household. SInce going back to windows life is so slow! Anyone out there help??

[theicepelican]

skype does work on my computer and it does recognize the CIT200... however, after i set up the default audio and ringer to the CIT 200 nothing gets forwarded to it, and the handset says 'Disconnected' am i missing something?

[Peepsalot]

skype does work on my computer and it does recognize the CIT200... however, after i set up the default audio and ringer to the CIT 200 nothing gets forwarded to it, and the handset says 'Disconnected' am i missing something?

If I had to guess, I'd say you're missing drivers, like everyone else.