Add serial port discovery (#1498)

Co-authored-by: Stefan Rueger <stefan.rueger@urclocks.com>

CMakeLists.txt

@@ -125,6 +125,7 @@ if(USE_STATIC_LIBS)
     set(PREFERRED_LIBFTDI libftdi.a ftdi)
     set(PREFERRED_LIBFTDI1 libftdi1.a ftdi1)
     set(PREFERRED_LIBREADLINE libreadline.a)
+    set(PREFERRED_LIBSERIALPORT libserialport.a)
     set(PREFERRED_LIBGPIOD libgpiod.a gpiod)
 else()
     set(PREFERRED_LIBELF elf)
@@ -134,6 +135,7 @@ else()
     set(PREFERRED_LIBFTDI ftdi)
     set(PREFERRED_LIBFTDI1 ftdi1)
     set(PREFERRED_LIBREADLINE readline)
+    set(PREFERRED_LIBSERIALPORT serialport)
     set(PREFERRED_LIBGPIOD gpiod)
 endif()
 
@@ -225,6 +227,15 @@ elseif(MSVC)
     set(HAVE_LIBREADLINE 1)
 endif()
 
+#-------------------------------------
+# Find libserialport
+
+find_library(HAVE_LIBSERIALPORT NAMES ${PREFERRED_LIBSERIALPORT})
+if(HAVE_LIBSERIALPORT)
+    set(LIB_LIBSERIALPORT ${HAVE_LIBSERIALPORT})
+    set(HAVE_LIBSERIALPORT 1)
+endif()
+
 # -------------------------------------
 # Find libgpiod, if needed
 if(HAVE_LINUXGPIO)
@@ -319,6 +330,7 @@ if (DEBUG_CMAKE)
     message(STATUS "HAVE_LIBFTDI: ${HAVE_LIBFTDI}")
     message(STATUS "HAVE_LIBFTDI1: ${HAVE_LIBFTDI1}")
     message(STATUS "HAVE_LIBREADLINE: ${HAVE_LIBREADLINE}")
+    message(STATUS "HAVE_LIBSERIALPORT: ${HAVE_LIBSERIALPORT}")
     message(STATUS "HAVE_LIBELF_H: ${HAVE_LIBELF_H}")
     message(STATUS "HAVE_LIBELF_LIBELF_H: ${HAVE_LIBELF_LIBELF_H}")
     message(STATUS "HAVE_USB_H: ${HAVE_USB_H}")
@@ -377,6 +389,12 @@ else()
     message(STATUS "DON'T HAVE libreadline")
 endif()
 
+if(HAVE_LIBSERIALPORT)
+    message(STATUS "DO HAVE    libserialport")
+else()
+    message(STATUS "DON'T HAVE libserialport")
+endif()
+
 if(BUILD_DOC)
 	message(STATUS "ENABLED    doc")
 else()