USB: Exposing second ACM channel as tty for Nokia S60 phones.

USB: Exposing second ACM channel as tty for Nokia S60 phones.

Nokia S60 phones expose two ACM channels. The first is a modem and is picked
up by the standard AT-command interface information in the CDC-ACM driver. The
second is marked as having a vendor-specific protocol. Normally, we don't
expose those as ttys. (On some other devices, they may be claimed by the
rndis_host driver and used as a network interface).

But on S60 this second ACM channel is the way that third-party S60 application
developers are expected to communicate over USB. It acts as a serial device
at the S60 end, and so it should on Linux too.

The list of devices is largely derived from:
http://wiki.forum.nokia.com/index.php/S60_Platform_and_device_identification_codes
http://wiki.forum.nokia.com/index.php/Nokia_USB_Product_IDs
and includes only the S60 3rd Edition+ devices documented there.

There are many devices for which the USB device ID is not documented,
including:
    Nokia 6290
    Nokia E63
    Nokia 5630 XpressMusic
    Nokia 5730 XpressMusic
    Nokia 6710 Navigator
    Nokia 6720 classic
    Nokia 6730 Classic
    Nokia 6760 slide
    Nokia 6790 slide
    Nokia 6790 Surge
    Nokia E52
    Nokia E55
    Nokia E71x (AT&T)
    Nokia E72
    Nokia E75
    Nokia E75 US+LTA variant
    Nokia N79
    Nokia N86 8MP
    Nokia 5230 (RM-588)
    Nokia 5230 (RM-594)
    Nokia 5530 XpressMusic
    Nokia 5530 XpressMusic (china)
    Nokia 5800 XM
    Nokia N97 (RM-506)
    Nokia N97 mini
    Nokia X6
It would be good to add those subsequently.

Signed-off-by: Adrian Taylor <aat@realvnc.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>