rt2x00_check_rev() was too specific for rt2500usb and rt73usb,
by adding the mask argument (instead of hardcoding it into
the function itself) we can use the function in rt2800usb as
well.

v2: Fix revision mask for rt2800usb
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Ralink released a new rt2870 driver, these are the obvious
differences I could find. It doesn't same to make my device
work better, but neither does it seem to regress...
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add support for the rt2800usb chipset.

Current problems:
 * Cannot scan 11n AP's
 * No TX during first minute after association
 * Broken Hardware encryption

Includes various patches from Mattias, Felix, Xose and Axel.
Signed-off-by: NMattias Nissler <mattias.nissler@gmx.de>
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NXose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: NAxel Kollhofer <rain_maker@root-forum.org>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>