[PATCH v2 libinput] udev: check wacom devices for a paired product id

[Peter Hutterer]

The newer Wacom Cintiqs have touch devices with a different PID than the pen
device. Use the new libwacom_get_paired_device call where available to pair
the two devices and give them the same device group.

This isn't that important just yet, so no need to force users to update to a
new libwacom version.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
Tested-by: Benjamin Tissoires <benjamin.tissoires at gmail.com>
---
Changes to v1:
- use AC_LINK_IFELSE instead of AC_CHECK_LIB
- re-instate the libinput-util include that got lost during a rebase (needed
  for the VENDOR_ID_WACOM define)

 configure.ac                 | 19 +++++++++++++
 udev/Makefile.am             |  9 ++++++-
 udev/libinput-device-group.c | 64 ++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 89 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 9e238b4..b6f7555 100644
--- a/configure.ac
+++ b/configure.ac
@@ -208,7 +208,26 @@ AC_ARG_ENABLE(libwacom,
 if test "x$use_libwacom" = "xyes"; then
 	PKG_CHECK_MODULES(LIBWACOM, [libwacom >= 0.12], [HAVE_LIBWACOM="yes"])
 	AC_DEFINE(HAVE_LIBWACOM, 1, [Build with libwacom])
+
+	OLD_LIBS=$LIBS
+	OLD_CFLAGS=$CFLAGS
+	LIBS="$LIBS $LIBWACOM_LIBS"
+	CFLAGS="$CFLAGS $LIBWACOM_CFLAGS"
+	AC_MSG_CHECKING([if libwacom_get_paired_device is available])
+	AC_LINK_IFELSE(
+		       [AC_LANG_PROGRAM([[#include <libwacom/libwacom.h>]],
+					[[libwacom_get_paired_device(NULL)]])],
+		       [AC_MSG_RESULT([yes])
+			AC_DEFINE(HAVE_LIBWACOM_GET_PAIRED_DEVICE, [1],
+				  [libwacom_get_paired_device() is available])
+		        [libwacom_have_get_paired_device=yes]],
+		       [AC_MSG_RESULT([no])
+		        [libwacom_have_get_paired_device=no]])
+	LIBS=$OLD_LIBS
+	CFLAGS=$OLD_CFLAGS
 fi
+AM_CONDITIONAL(HAVE_LIBWACOM_GET_PAIRED_DEVICE,
+	       [test "x$libwacom_have_get_paired_device" == "xyes"])
 
 AM_CONDITIONAL(HAVE_VALGRIND, [test "x$VALGRIND" != "x"])
 AM_CONDITIONAL(BUILD_TESTS, [test "x$build_tests" = "xyes"])
diff --git a/udev/Makefile.am b/udev/Makefile.am
index cfb854e..f06dc56 100644
--- a/udev/Makefile.am
+++ b/udev/Makefile.am
@@ -7,9 +7,16 @@ litest_rules = 80-libinput-device-groups-litest.rules \
 noinst_SCRIPTS = $(litest_rules)
 
 libinput_device_group_SOURCES = libinput-device-group.c
-libinput_device_group_CFLAGS = $(LIBUDEV_CFLAGS) $(GCC_CFLAGS)
+libinput_device_group_CFLAGS = -I$(top_srcdir)/src \
+			       $(LIBUDEV_CFLAGS) \
+			       $(GCC_CFLAGS)
 libinput_device_group_LDADD = $(LIBUDEV_LIBS)
 
+if HAVE_LIBWACOM_GET_PAIRED_DEVICE
+libinput_device_group_CFLAGS += $(LIBWACOM_CFLAGS)
+libinput_device_group_LDADD += $(LIBWACOM_LIBS)
+endif
+
 libinput_model_quirks_SOURCES = libinput-model-quirks.c
 libinput_model_quirks_CFLAGS = \
 			       -I$(top_srcdir)/src \
diff --git a/udev/libinput-device-group.c b/udev/libinput-device-group.c
index ab9409b..fa70e11 100644
--- a/udev/libinput-device-group.c
+++ b/udev/libinput-device-group.c
@@ -21,11 +21,49 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <libudev.h>
 
+#include "libinput-util.h"
+
+#if HAVE_LIBWACOM_GET_PAIRED_DEVICE
+#include <libwacom/libwacom.h>
+
+static void
+wacom_handle_paired(struct udev_device *device,
+		    int *vendor_id,
+		    int *product_id)
+{
+	WacomDeviceDatabase *db = NULL;
+	WacomDevice *tablet = NULL;
+	const WacomMatch *paired;
+
+	db = libwacom_database_new();
+	if (!db)
+		goto out;
+
+	tablet = libwacom_new_from_usbid(db, *vendor_id, *product_id, NULL);
+	if (!tablet)
+		goto out;
+	paired = libwacom_get_paired_device(tablet);
+	if (!paired)
+		goto out;
+
+	*vendor_id = libwacom_match_get_vendor_id(paired);
+	*product_id = libwacom_match_get_product_id(paired);
+
+out:
+	if (tablet)
+		libwacom_destroy(tablet);
+	if (db)
+		libwacom_database_destroy(db);
+}
+#endif
+
 int main(int argc, char **argv)
 {
 	int rc = 1;
@@ -34,6 +72,7 @@ int main(int argc, char **argv)
 	const char *syspath,
 	           *phys = NULL;
 	const char *product;
+	int bustype, vendor_id, product_id, version;
 	char group[1024];
 	char *str;
 
@@ -73,8 +112,29 @@ int main(int argc, char **argv)
 	   on that*/
 	product = udev_device_get_property_value(device, "PRODUCT");
 	if (!product)
-		product = "";
-	snprintf(group, sizeof(group), "%s:%s", product, phys);
+		product = "00/00/00/00";
+
+	if (sscanf(product,
+		   "%x/%x/%x/%x",
+		   &bustype,
+		   &vendor_id,
+		   &product_id,
+		   &version) != 4) {
+		snprintf(group, sizeof(group), "%s:%s", product, phys);
+	} else {
+#if HAVE_LIBWACOM_GET_PAIRED_DEVICE
+	    if (vendor_id == VENDOR_ID_WACOM)
+		    wacom_handle_paired(device, &vendor_id, &product_id);
+#endif
+	    snprintf(group,
+		     sizeof(group),
+		     "%x/%x/%x/%x:%s",
+		     bustype,
+		     vendor_id,
+		     product_id,
+		     version,
+		     phys);
+	}
 
 	str = strstr(group, "/input");
 	if (str)
-- 
2.7.4