Add Find GPIOD CMake file for C++

cmake_modules/FindGPIOD.cmake

@@ -0,0 +1,55 @@
+# - Try to find GPIOD
+# Once done this will define
+#
+#  GPIOD_FOUND - system has libgpiod
+#  GPIOD_INCLUDE_DIR - the libgpiod include directory
+#  GPIOD_LIBRARIES - Link these to use libgpiod
+#
+# N.B. This is for C++ only, you need to include
+#
+#include <gpiod.hpp>
+#
+# Redistribution and use is allowed according to the terms of the BSD license.
+# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
+
+if (GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)
+
+  # in cache already
+  set(GPIOD_FOUND TRUE)
+  message(STATUS "Found libgpiod: ${GPIOD_LIBRARIES}")
+
+else (GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)
+
+  find_path(GPIOD_INCLUDE_DIR gpiod.hpp
+    ${_obIncDir}
+    ${GNUWIN32_DIR}/include
+    /usr/local/include
+  )
+
+  find_library(GPIOD_LIBRARIES NAMES gpiodcxx
+    PATHS
+    ${_obLinkDir}
+    ${GNUWIN32_DIR}/lib
+    /usr/local/lib
+  )
+
+  if(GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)
+    set(GPIOD_FOUND TRUE)
+  else (GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)
+    set(GPIOD_FOUND FALSE)
+  endif(GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)
+
+
+  if (GPIOD_FOUND)
+    if (NOT GPIOD_FIND_QUIETLY)
+      message(STATUS "Found GPIOD: ${GPIOD_LIBRARIES}")
+    endif (NOT GPIOD_FIND_QUIETLY)
+  else (GPIOD_FOUND)
+    if (GPIOD_FIND_REQUIRED)
+      message(FATAL_ERROR "libgpiod not found. Please install libgpiod-dev")
+    endif (GPIOD_FIND_REQUIRED)
+  endif (GPIOD_FOUND)
+
+  mark_as_advanced(GPIOD_INCLUDE_DIR GPIOD_LIBRARIES)
+
+endif (GPIOD_INCLUDE_DIR AND GPIOD_LIBRARIES)