[IrDA]: Kingsun KS-959 IrDA USB driver

This dongle does not follow the usb-irda specification, so it needs its own
special driver. First, it uses control URBs for data transfer, instead of
bulk or interrupt transfers; the only interrupt endpoint exposed seems to
be a dummy to prevent the interface from being rejected. Second, it uses
obfuscation and padding at the USB traffic level, for no apparent reason
other than to make reverse engineering harder (full details on obfuscation
in comments at beginning of source). Although it is advertised as a "4 Mbps
FIR dongle", it apparently loses packets at speeds greater than 57600 bps.

On plugin, this dongle reports vendor and device IDs: 0x07d0:0x4959 .

The Windows driver that is used normally to control this dongle has a
filename of KS-959.SYS .
Signed-off-by: Alex Villacís Lasso <a_villacis@palosanto.com>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/irda/Kconfig

@@ -176,6 +176,20 @@ config KSDAZZLE_DONGLE
 	  To compile it as a module, choose M here: the module will be called
 	  ksdazzle-sir.
 
+config KS959_DONGLE
+	tristate "KingSun KS-959 IrDA-USB dongle (EXPERIMENTAL)"
+	depends on IRDA && USB && EXPERIMENTAL
+	help
+	  Say Y or M here if you want to build support for the KingSun KS-959
+	  IrDA-USB bridge device driver.
+
+	  This USB bridge does not conform to the IrDA-USB device class
+	  specification, and therefore needs its own specific driver. This
+	  dongle supports SIR speeds only (9600 through 57600 bps).
+
+	  To compile it as a module, choose M here: the module will be called
+	  ks959-sir.
+
 comment "Old SIR device drivers"
 
 config IRPORT_SIR

drivers/net/irda/Makefile

@@ -48,6 +48,7 @@ obj-$(CONFIG_TOIM3232_DONGLE)	+= toim3232-sir.o
 obj-$(CONFIG_EP7211_DONGLE)	+= ep7211-sir.o
 obj-$(CONFIG_KINGSUN_DONGLE)	+= kingsun-sir.o
 obj-$(CONFIG_KSDAZZLE_DONGLE)	+= ksdazzle-sir.o
+obj-$(CONFIG_KS959_DONGLE)    	+= ks959-sir.o
 
 # The SIR helper module
 sir-dev-objs := sir_dev.o sir_dongle.o