usb gadget: new "CDC Composite" gadget driver
This is a simple example of a composite gadget, combining two
Communications Class Device (CDC) functions: ECM and ACM.
This provides a clear example of how the composite gadget framework
is intended to work. It's surprising that MS-Windows (or at least,
XP and previous) won't "just work" with something this simple...
One /proc/bus/usb/devices listing looks like:
T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 46 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0525 ProdID=a4aa Rev= 3.01
S: Manufacturer=Linux 2.6.26-rc6-pnut with net2280
S: Product=CDC Composite Gadget
C:* #Ifs= 4 Cfg#= 1 Atr=c0 MxPwr= 2mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=06 Prot=00 Driver=cdc_ether
E: Ad=83(I) Atr=03(Int.) MxPS= 16 Ivl=32ms
I: If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
I:* If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=cdc_acm
E: Ad=86(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
I:* If#= 3 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_acm
E: Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Not all USB peripheral controller hardware can support this driver.
All the highspeed-capable peripheral controllers with drivers now in
the mainline kernel seem to support this, as does omap_udc. But
many full speed controllers don't have enough endpoints, or (as with
the PXA controllers) don't support altsettings.
Lightly tested.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index d6bab0d..a460706 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -586,6 +586,19 @@
For more information, see Documentation/usb/gadget_printer.txt
which includes sample code for accessing the device file.
+config USB_CDC_COMPOSITE
+ tristate "CDC Composite Device (Ethernet and ACM)"
+ help
+ This driver provides two functions in one configuration:
+ a CDC Ethernet (ECM) link, and a CDC ACM (serial port) link.
+
+ This driver requires four bulk and two interrupt endpoints,
+ plus the ability to handle altsettings. Not all peripheral
+ controllers are that capable.
+
+ Say "y" to link the driver statically, or "m" to build a
+ dynamically linked module.
+
# put drivers that need isochronous transfer support (for audio
# or video class gadget drivers), or specific hardware, here.