Simple question on OHCI.

[tonytian]

I am trying to write a driver for my firewire camera. In my machine, I currently have a PCIe to Firewire adapter, and I connect my camera to the adapter using a firewire cable. My PCI enumeration can get me to the OHCI registers of the adapter. My question is, how can my OS talk to the camera? Is the camera going to be a subsystem of the adapter or there will be some hardware-based mappings between the adapter and camera?

I am new to device drivers, and hope I can get some help here. Thanks!

[Combuster]

You just picked up two of the rarest devices in the hobby scene. Firewire is not a requirement for basic stuff, and information about camera interfaces is pretty much nonexistant.

That said, anything not directly connected to a PCI bus typically functions as a computer at another end of a small network, with the network being controlled by the firewire driver. How it works exactly, I don't know because I don't have any machines with firewire of my own.

[bewing]

As Combuster basically said, your firewire adapter will create a bus. Your firewire driver will probably enumerate that bus, and will communicate with the device(s) on that bus using the firewire protocol. AFAIK, it's a packetizing protocol -- and device commands will be embedded in the packets. -- Doesn't something like this: http://ieeexplore.ieee.org/servlet/opac ... er=4659231 give enough info?

[tonytian]

I see. All I want is to make my OS support a camera. I first thought USB was too complex for me and firewire may be easier. Looks like both are very complicated. Any suggestions?

As Combuster basically said, your firewire adapter will create a bus. Your firewire driver will probably enumerate that bus, and will communicate with the device(s) on that bus using the firewire protocol. AFAIK, it's a packetizing protocol -- and device commands will be embedded in the packets. -- Doesn't something like this: http://ieeexplore.ieee.org/servlet/opac ... er=4659231 give enough info?

[gravaera]

Yo:

Any suggestions?

Well, beyond, "Choose one of them" or "Give up on the idea and move on", I'm not sure what other suggestions can be made. Maybe if somebody wants to be ridiculous they can say something like, "Rip out the cable and try to connect it via the serial port", just to add that extra bit of diversity.

--Peace out
gravaera

[tonytian]

Yo:

Any suggestions?

Well, beyond, "Choose one of them" or "Give up on the idea and move on", I'm not sure what other suggestions can be made. Maybe if somebody wants to be ridiculous they can say something like, "Rip out the cable and try to connect it via the serial port", just to add that extra bit of diversity.

--Peace out
gravaera