build: Add a way to conditionally compile the controller

Currently, there is two supported controller: TPC/IP and bluetooth.
Add some options to enable or disable them at build time.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

Makefile.am

@@ -9,6 +9,12 @@ gbridge_SOURCES = main.c \
 		  debug.c \
 		  greybus.c \
 		  svc.c \
-		  controller.c \
-		  bluetooth.c \
-		  tcpip.c
+		  controller.c
+
+if TPCIP
\ No newline at end of file
+gbridge_SOURCES += tcpip.c
+endif
+
+if BLUETOOTH
+gbridge_SOURCES += bluetooth.c
+endif

configure.ac

@@ -13,7 +13,6 @@ AC_PROG_INSTALL
 AC_CHECK_LIB([nl-3], [nl_socket_alloc])
 AC_CHECK_LIB([nl-genl-3], [genl_register_family])
 AC_CHECK_LIB([pthread], [pthread_create])
-AC_CHECK_LIB([bluetooth], [hci_inquiry])
 AC_CHECK_LIB([avahi-common], [main])
 AC_CHECK_LIB([avahi-client], [main])
 
@@ -23,6 +22,26 @@ AC_CONFIG_FILES([
 	Makefile
 ])
 
+AC_ARG_ENABLE([bluetooth],
+[  --enable-bluetooth    Enable bluetooth],
+[case "${enableval}" in
+	yes) bluetooth=true ;
+	     AC_CHECK_LIB([bluetooth], [hci_inquiry]) ;;
+	no)  bluetooth=false ;;
+	*) AC_MSG_ERROR([bad value ${enableval} for --enable-bluetooth]) ;;
+esac])
+AM_CONDITIONAL([BLUETOOTH], [test x$bluetooth = xtrue])
+
+AC_ARG_ENABLE([tcpip],
+[  --enable-tcpip    Enable TCP/IP],
+[case "${enableval}" in
+	yes) tcpip=true ;
+	     AC_DEFINE([HAVE_TCPIP], [1], ["TCP/IP support"]) ;;
+	no)  tcpip=false ;;
+	*) AC_MSG_ERROR([bad value ${enableval} for --enable-tcpip]) ;;
+esac])
+AM_CONDITIONAL([TPCIP], [test x$tcpip = xtrue])
+
 AC_ARG_VAR([GBDIR], ["greybus sources directory"])
 AS_IF([test "$GBDIR" = ""], [
   AC_MSG_ERROR([Environment variable GBDIR needs to be set])

controller.c

@@ -364,8 +364,12 @@ static void register_controller(struct controller *controller)
 
 static void register_controllers(void)
 {
+#ifdef HAVE_LIBBLUETOOTH
 	register_controller(&bluetooth_controller);
+#endif
+#ifdef HAVE_TCPIP
 	register_controller(&tcpip_controller);
+#endif
 }
 
 static void *controller_loop(void *data)

gbridge.h

@@ -19,6 +19,7 @@
 #ifndef _GBRIDGE_H_
 #define _GBRIDGE_H_
 
+#include <config.h>
 #include <stdint.h>
 #include <linux/types.h>
 #include <sys/queue.h>