gnu: Add libmtp.

* gnu/packages/libusb.scm (libmtp): New variable.

gnu/packages/libusb.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012 Nikita Karetnikov <nikita@karetnikov.org>
+;;; Copyright © 2015 Andreas Enge <andreas@enge.fr>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -21,7 +22,9 @@
   #:use-module (guix licenses)
   #:use-module (guix packages)
   #:use-module (guix download)
-  #:use-module (guix build-system gnu))
+  #:use-module (guix build-system gnu)
+  #:use-module (gnu packages gnupg)
+  #:use-module (gnu packages pkg-config))
 
 (define-public libusb
   (package
@@ -42,3 +45,38 @@
      "Libusb is a library that gives applications easy access to USB
 devices on various operating systems.")
     (license lgpl2.1+)))
+
+(define-public libmtp
+  (package
+    (name "libmtp")
+    (version "1.1.8")
+    (source (origin
+             (method url-fetch)
+             (uri (string-append "mirror://sourceforge/libmtp/" version
+                                 "/libmtp-" version ".tar.gz"))
+             (sha256
+               (base32
+                "10i2vnj8r6hyd61xgyhmxbsissq971g50fhm1h6mc3m4d99qg7iz"))))
+    (build-system gnu-build-system)
+    (native-inputs
+     `(("pkg-config" ,pkg-config)))
+    (inputs
+     `(("libgcrypt" ,libgcrypt)
+       ("libusb" ,libusb)))
+    (arguments
+     `(#:configure-flags
+       (list (string-append "--with-udev="
+                            (assoc-ref %outputs "out")
+                            "/lib/udev"))))
+    (home-page "http://libmtp.sourceforge.net/")
+    (synopsis "Library implementing the Media Transfer Protocol")
+    (description "Libmtp implements an MTP (Media Transfer Protocol)
+initiator, which means that it initiates MTP sessions with devices.  The
+devices responding are known as MTP responders.  Libmtp runs on devices
+with a USB host controller interface.  It implements MTP Basic, which was
+proposed for standardization.")
+    ;; COPYING contains lgpl2.1, while files headers give
+    ;; "GNU Lesser General Public License as published by the Free Software
+    ;; Foundation; either version 2 of the License, or (at your option) any
+    ;; later version."
+    (license lgpl2.1+)))