Re: multiple drivers, single device

From: Jeff Garzik
Date: Tue Feb 12 2008 - 13:09:00 EST


Roland Dreier wrote:
> The work I'm doing here is for stupid PCI firmware engineers, who have
> created devices that are different things, all bound up under the same
> PCI device. I'm thinking of watchdog timers and random number
> generator and i2c controller on the same PCI device, or even the more
> basic, frame buffer and DRM access to the same PCI video device.
> > The OLPC is a good example of hardware that needs this kind of
> functionality.

Sounds interesting. I've been meaning to work on this too for quite a
while, but I'm glad to see you beat me to it.

An example of an in-tree use case for this would be the mlx4 drivers--
you can look at drivers/net/mlx4/intf.c to see the simple stupid
solution I came up with to allow an IB and a NIC (not yet upstream)
driver to share the same PCI device. A good test for your stuff would
be if it simplifies the code from the ad hoc solution I came up with.

Our APIs are written such that the PCI device probe function is the starting point for registering IB and NIC. No need for anything new.

Jeff



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/