Set up basic USB support with M-Stack.

Author: Elemecca

Modules/FindMStack.cmake

@@ -0,0 +1,59 @@
+#.rst:
+# FindMStack
+# -----------
+#
+# Finds the M-Stack USB stack for Microchip PIC MCUs.
+#
+# Copyright 2016 Sam Hanes
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+set(MStack_ROOT external/m-stack
+    CACHE PATH "the root of the M-Stack source checkout"
+)
+get_filename_component(MStack_ROOT "${MStack_ROOT}" ABSOLUTE)
+
+set(MStack_USB_ROOT ${MStack_ROOT}/usb)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(MStack
+    REQUIRED_VARS
+        MStack_ROOT
+)
+
+if(NOT MStack_FOUND)
+    return()
+endif()
+
+add_library(MStack INTERFACE)
+target_sources(MStack INTERFACE
+    ${MStack_USB_ROOT}/src/usb.c
+)
+target_include_directories(MStack INTERFACE
+    ${MStack_ROOT}/usb/include
+)
+
+add_library(MStack_HID INTERFACE)
+target_sources(MStack_HID INTERFACE
+    ${MStack_USB_ROOT}/src/usb_hid.c
+)
+target_link_libraries(MStack_HID
+    INTERFACE MStack
+)