usb: usbtmc: Add ioctl for generic requests on control

Quoted 11 lines · Guido Kiener

include/uapi/linux/usb/tmc.h +1 -0

@@ -4,6 +4,7 @@
  * Copyright (C) 2008 Novell, Inc.
  * Copyright (C) 2008 Greg Kroah-Hartman <[email protected]>
  * Copyright (C) 2015 Dave Penkler <[email protected]>
+ * Copyright (C) 2018 IVI Foundation, Inc.
  *
  * This file holds USB constants defined by the USB Device Class
  * and USB488 Subclass Definitions for Test and Measurement devices

include/uapi/linux/usb/tmc.h line 50

Quoted 10 lines

include/uapi/linux/usb/tmc.h +7 -0

@@ -40,6 +41,19 @@
 #define USBTMC488_REQUEST_GOTO_LOCAL			161
 #define USBTMC488_REQUEST_LOCAL_LOCKOUT			162
 
+struct usbtmc_request {
+	__u8 bRequestType;
+	__u8 bRequest;
+	__u16 wValue;
+	__u16 wIndex;
+	__u16 wLength;
+} __attribute__ ((packed));

This really is just 'struct usb_ctrlrequest', right? That's already defined in our uapi files. Why not use that?

Bonus is, if you use that, you get the proper endian notation, which you don't have here, which means this is broken on big endian machines :(

Try doing that, and fix up the endian issue.