usb: gadget: printer: add configfs support
Add support for configfs interface so that f_printer can be used as a
component of usb gadgets composed with it.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index 076ac7b..f45b2bf 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -19,6 +19,7 @@
16. UAC1 function
17. UAC2 function
18. UVC function
+19. PRINTER function
1. ACM function
@@ -726,3 +727,49 @@
http://www.spinics.net/lists/linux-usb/msg99220.html
host: luvcview -f yuv
+
+19. PRINTER function
+====================
+
+The function is provided by usb_f_printer.ko module.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory is "printer".
+The printer function provides these attributes in its function directory:
+
+ pnp_string - Data to be passed to the host in pnp string
+ q_len - Number of requests per endpoint
+
+Testing the PRINTER function
+----------------------------
+
+The most basic testing:
+
+device: run the gadget
+# ls -l /devices/virtual/usb_printer_gadget/
+
+should show g_printer<number>.
+
+If udev is active, then /dev/g_printer<number> should appear automatically.
+
+host:
+
+If udev is active, then e.g. /dev/usb/lp0 should appear.
+
+host->device transmission:
+
+device:
+# cat /dev/g_printer<number>
+host:
+# cat > /dev/usb/lp0
+
+device->host transmission:
+
+# cat > /dev/g_printer<number>
+host:
+# cat /dev/usb/lp0
+
+More advanced testing can be done with the prn_example
+described in Documentation/usb/gadget-printer.txt.