[IrDA]: KingSun/DonShine USB IrDA dongle support.

This dongle does not follow the usb-irda specification, so it needs its
own special driver. In addition, it uses interrupt endpoints instead of
bulk ones as the rest of USB IrDA dongles supported by Linux (just to be
different?) and data reads need to be parsed to extract the valid bytes
before being unwrapped (details in the comment at the start of the
source). No speed commands have been discovered for this dongle, and I
suspect it does not have any at all.

On plugin, this dongle reports vendor and device IDs: 0x07c0:0x4200 .

The Windows driver that is used normally to control this dongle has a
filename of DSIR620.SYS .
Signed-off-by: Alex Villac�s 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

@@ -141,6 +141,20 @@ config ACT200L_DONGLE
 	  To activate support for ACTiSYS IR-200L dongle you will have to
 	  start irattach like this: "irattach -d act200l".
 
+config KINGSUN_DONGLE
+	tristate "KingSun/DonShine DS-620 IrDA-USB dongle"
+	depends on IRDA && USB && EXPERIMENTAL
+	help
+	  Say Y or M here if you want to build support for the KingSun/DonShine
+	  DS-620 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 speed only (9600 bps).
+
+	  To compile it as a module, choose M here: the module will be called
+	  kingsun-sir.
+
 comment "Old SIR device drivers"
 
 config IRPORT_SIR

drivers/net/irda/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_MCP2120_DONGLE)	+= mcp2120-sir.o
 obj-$(CONFIG_ACT200L_DONGLE)	+= act200l-sir.o
 obj-$(CONFIG_MA600_DONGLE)	+= ma600-sir.o
 obj-$(CONFIG_TOIM3232_DONGLE)	+= toim3232-sir.o
+obj-$(CONFIG_KINGSUN_DONGLE)	+= kingsun-sir.o
 
 # The SIR helper module
 sir-dev-objs := sir_dev.o sir_dongle.o