USB: add Printer Gadget Driver

G_PRINTER: Adds a USB printer gadget driver for use in printer firmware.

This adds a USB printer gadget driver for use in printer firmware.
The printer gadget channels data between the USB host and a userspace
program driving the print engine. The user space program reads and
writes the device file /dev/g_printer to receive or send printer data.
It can use ioctl calls to the device file to get or set printer status.

Signed-off-by: Craig W. Nadler <craig@nadler.us>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/usb/gadgetfs.h b/include/linux/usb/gadgetfs.h
index e8654c338729..981e9ceb8fe7 100644
--- a/include/linux/usb/gadgetfs.h
+++ b/include/linux/usb/gadgetfs.h
@@ -59,6 +59,11 @@ struct usb_gadgetfs_event {
 };
 
 
+/* The 'g' code is also used by printer gadget ioctl requests.
+ * Don't add any colliding codes to either driver, and keep
+ * them in unique ranges (size 0x20 for now).
+ */
+
 /* endpoint ioctls */
 
 /* IN transfers may be reported to the gadget driver as complete