Hook up libevdev as backend

libevdev wraps the various peculiarities of the evdev kernel API into a
type-safe API. It also buffers the device so checking for specific features at
a later time is easier than re-issuing the ioctls. Plus, it gives us almost
free support for SYN_DROPPED events (in the following patch).

This patch switches all the bit checks over to libevdev and leaves the event
processing as-is. Makes it easier to review.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>

configure.ac

@@ -44,6 +44,7 @@ AC_CHECK_DECL(CLOCK_MONOTONIC,[],
 PKG_PROG_PKG_CONFIG()
 PKG_CHECK_MODULES(MTDEV, [mtdev >= 1.1.0])
 PKG_CHECK_MODULES(LIBUDEV, [libudev])
+PKG_CHECK_MODULES(LIBEVDEV, [libevdev >= 0.4])
 
 if test "x$GCC" = "xyes"; then
 	GCC_CFLAGS="-Wall -Wextra -Wno-unused-parameter -g -Wstrict-prototypes -Wmissing-prototypes -fvisibility=hidden"
@@ -64,20 +65,16 @@ AC_ARG_ENABLE(tests,
 	      [build_tests="$enableval"],
 	      [build_tests="auto"])
 
-PKG_CHECK_MODULES(LIBEVDEV, [libevdev >= 0.4], [HAVE_LIBEVDEV="yes"], [HAVE_LIBEVDEV="no"])
 PKG_CHECK_MODULES(CHECK, [check >= 0.9.9], [HAVE_CHECK="yes"], [HAVE_CHECK="no"])
 
 if test "x$build_tests" = "xauto"; then
-	if test "x$HAVE_CHECK" = "xyes" -a "x$HAVE_LIBEVDEV" = "xyes"; then
+	if test "x$HAVE_CHECK" = "xyes"; then
 		build_tests="yes"
 	fi
 fi
 if test "x$build_tests" = "xyes" -a "x$HAVE_CHECK" = "xno"; then
        AC_MSG_ERROR([Cannot build tests, check is missing])
 fi
-if test "x$build_tests" = "xyes" -a "x$HAVE_LIBEVDEV" = "xno"; then
-       AC_MSG_ERROR([Cannot build tests, libevdev is missing])
-fi
 
 AM_CONDITIONAL(BUILD_TESTS, [test "x$build_tests" = "xyes"])
 

src/Makefile.am

@@ -20,9 +20,11 @@ libinput_la_SOURCES =			\
 
 libinput_la_LIBADD = $(MTDEV_LIBS) \
 		     $(LIBUDEV_LIBS) \
+		     $(LIBEVDEV_LIBS) \
 		     -lm
 libinput_la_CFLAGS = $(MTDEV_CFLAGS)	\
 		     $(LIBUDEV_CFLAGS)	\
+		     $(LIBEVDEV_CFLAGS)	\
 		     $(GCC_CFLAGS)
 
 pkgconfigdir = $(libdir)/pkgconfig

src/evdev-touchpad.c

@@ -170,16 +170,16 @@ struct touchpad_dispatch {
 static enum touchpad_model
 get_touchpad_model(struct evdev_device *device)
 {
-	struct input_id id;
+	int vendor, product;
 	unsigned int i;
 
-	if (ioctl(device->fd, EVIOCGID, &id) < 0)
-		return TOUCHPAD_MODEL_UNKNOWN;
+	vendor = libevdev_get_id_vendor(device->evdev);
+	product = libevdev_get_id_product(device->evdev);
 
 	for (i = 0; i < ARRAY_LENGTH(touchpad_spec_table); i++)
-		if (touchpad_spec_table[i].vendor == id.vendor &&
+		if (touchpad_spec_table[i].vendor == vendor &&
 		    (!touchpad_spec_table[i].product ||
-		     touchpad_spec_table[i].product == id.product))
+		     touchpad_spec_table[i].product == product))
 			return touchpad_spec_table[i].model;
 
 	return TOUCHPAD_MODEL_UNKNOWN;
@@ -730,9 +730,7 @@ touchpad_init(struct touchpad_dispatch *touchpad,
 {
 	struct motion_filter *accel;
 
-	unsigned long prop_bits[INPUT_PROP_MAX];
-	struct input_absinfo absinfo;
-	unsigned long abs_bits[NBITS(ABS_MAX)];
+	const struct input_absinfo *absinfo;
 
 	bool has_buttonpad;
 
@@ -746,16 +744,13 @@ touchpad_init(struct touchpad_dispatch *touchpad,
 	/* Detect model */
 	touchpad->model = get_touchpad_model(device);
 
-	ioctl(device->fd, EVIOCGPROP(sizeof(prop_bits)), prop_bits);
-	has_buttonpad = TEST_BIT(prop_bits, INPUT_PROP_BUTTONPAD);
+	has_buttonpad = libevdev_has_property(device->evdev, INPUT_PROP_BUTTONPAD);
 
 	/* Configure pressure */
-	ioctl(device->fd, EVIOCGBIT(EV_ABS, sizeof(abs_bits)), abs_bits);
-	if (TEST_BIT(abs_bits, ABS_PRESSURE)) {
-		ioctl(device->fd, EVIOCGABS(ABS_PRESSURE), &absinfo);
+	if ((absinfo = libevdev_get_abs_info(device->evdev, ABS_PRESSURE))) {
 		configure_touchpad_pressure(touchpad,
-					    absinfo.minimum,
-					    absinfo.maximum);
+					    absinfo->minimum,
+					    absinfo->maximum);
 	}
 
 	/* Configure acceleration factor */

src/evdev.c

@@ -493,11 +493,7 @@ evdev_device_dispatch(void *data)
 static int
 evdev_configure_device(struct evdev_device *device)
 {
-	struct input_absinfo absinfo;
-	unsigned long ev_bits[NBITS(EV_MAX)];
-	unsigned long abs_bits[NBITS(ABS_MAX)];
-	unsigned long rel_bits[NBITS(REL_MAX)];
-	unsigned long key_bits[NBITS(KEY_MAX)];
+	const struct input_absinfo *absinfo;
 	int has_abs, has_rel, has_mt;
 	int has_button, has_keyboard, has_touch;
 	unsigned int i;
@@ -509,84 +505,71 @@ evdev_configure_device(struct evdev_device *device)
 	has_keyboard = 0;
 	has_touch = 0;
 
-	ioctl(device->fd, EVIOCGBIT(0, sizeof(ev_bits)), ev_bits);
-	if (TEST_BIT(ev_bits, EV_ABS)) {
-		ioctl(device->fd, EVIOCGBIT(EV_ABS, sizeof(abs_bits)),
-		      abs_bits);
+	if (libevdev_has_event_type(device->evdev, EV_ABS)) {
 
-		if (TEST_BIT(abs_bits, ABS_X)) {
-			ioctl(device->fd, EVIOCGABS(ABS_X), &absinfo);
-			device->abs.min_x = absinfo.minimum;
-			device->abs.max_x = absinfo.maximum;
+		if ((absinfo = libevdev_get_abs_info(device->evdev, ABS_X))) {
+			device->abs.min_x = absinfo->minimum;
+			device->abs.max_x = absinfo->maximum;
 			has_abs = 1;
 		}
-		if (TEST_BIT(abs_bits, ABS_Y)) {
-			ioctl(device->fd, EVIOCGABS(ABS_Y), &absinfo);
-			device->abs.min_y = absinfo.minimum;
-			device->abs.max_y = absinfo.maximum;
+		if ((absinfo = libevdev_get_abs_info(device->evdev, ABS_Y))) {
+			device->abs.min_y = absinfo->minimum;
+			device->abs.max_y = absinfo->maximum;
 			has_abs = 1;
 		}
                 /* We only handle the slotted Protocol B in weston.
                    Devices with ABS_MT_POSITION_* but not ABS_MT_SLOT
                    require mtdev for conversion. */
-		if (TEST_BIT(abs_bits, ABS_MT_POSITION_X) &&
-		    TEST_BIT(abs_bits, ABS_MT_POSITION_Y)) {
-			ioctl(device->fd, EVIOCGABS(ABS_MT_POSITION_X),
-			      &absinfo);
-			device->abs.min_x = absinfo.minimum;
-			device->abs.max_x = absinfo.maximum;
-			ioctl(device->fd, EVIOCGABS(ABS_MT_POSITION_Y),
-			      &absinfo);
-			device->abs.min_y = absinfo.minimum;
-			device->abs.max_y = absinfo.maximum;
+		if (libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_POSITION_X) &&
+		    libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_POSITION_Y)) {
+			absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_POSITION_X);
+			device->abs.min_x = absinfo->minimum;
+			device->abs.max_x = absinfo->maximum;
+			absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_POSITION_Y);
+			device->abs.min_y = absinfo->minimum;
+			device->abs.max_y = absinfo->maximum;
 			device->is_mt = 1;
 			has_touch = 1;
 			has_mt = 1;
 
-			if (!TEST_BIT(abs_bits, ABS_MT_SLOT)) {
+			if (!libevdev_has_event_code(device->evdev, EV_ABS, ABS_MT_SLOT)) {
 				device->mtdev = mtdev_new_open(device->fd);
 				if (!device->mtdev)
 					return -1;
 				device->mt.slot = device->mtdev->caps.slot.value;
 			} else {
-				ioctl(device->fd, EVIOCGABS(ABS_MT_SLOT),
-				      &absinfo);
-				device->mt.slot = absinfo.value;
+				device->mt.slot = libevdev_get_current_slot(device->evdev);
 			}
 		}
 	}
-	if (TEST_BIT(ev_bits, EV_REL)) {
-		ioctl(device->fd, EVIOCGBIT(EV_REL, sizeof(rel_bits)),
-		      rel_bits);
-		if (TEST_BIT(rel_bits, REL_X) || TEST_BIT(rel_bits, REL_Y))
+	if (libevdev_has_event_code(device->evdev, EV_REL, REL_X) ||
+	    libevdev_has_event_code(device->evdev, EV_REL, REL_Y))
 			has_rel = 1;
-	}
-	if (TEST_BIT(ev_bits, EV_KEY)) {
-		ioctl(device->fd, EVIOCGBIT(EV_KEY, sizeof(key_bits)),
-		      key_bits);
-		if (TEST_BIT(key_bits, BTN_TOOL_FINGER) &&
-		    !TEST_BIT(key_bits, BTN_TOOL_PEN) &&
+
+	if (libevdev_has_event_type(device->evdev, EV_KEY)) {
+		if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_FINGER) &&
+		    !libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_PEN) &&
 		    (has_abs || has_mt)) {
 			device->dispatch = evdev_touchpad_create(device);
 		}
 		for (i = KEY_ESC; i < KEY_MAX; i++) {
 			if (i >= BTN_MISC && i < KEY_OK)
 				continue;
-			if (TEST_BIT(key_bits, i)) {
+			if (libevdev_has_event_code(device->evdev, EV_KEY, i)) {
 				has_keyboard = 1;
 				break;
 			}
 		}
-		if (TEST_BIT(key_bits, BTN_TOUCH))
+		if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOUCH))
 			has_touch = 1;
 		for (i = BTN_MISC; i < BTN_JOYSTICK; i++) {
-			if (TEST_BIT(key_bits, i)) {
+			if (libevdev_has_event_code(device->evdev, EV_KEY, i)) {
 				has_button = 1;
 				break;
 			}
 		}
 	}
-	if (TEST_BIT(ev_bits, EV_LED))
+	if (libevdev_has_event_type(device->evdev, EV_LED))
 		has_keyboard = 1;
 
 	if ((has_abs || has_rel) && has_button)
@@ -606,7 +589,7 @@ evdev_device_create(struct libinput_seat *seat,
 {
 	struct libinput *libinput = seat->libinput;
 	struct evdev_device *device;
-	char devname[256] = "unknown";
+	int rc;
 	int fd;
 	int unhandled_device = 0;
 
@@ -626,6 +609,10 @@ evdev_device_create(struct libinput_seat *seat,
 
 	libinput_device_init(&device->base, seat);
 
+	rc = libevdev_new_from_fd(fd, &device->evdev);
+	if (rc != 0)
+		return NULL;
+
 	device->seat_caps = 0;
 	device->is_mt = 0;
 	device->mtdev = NULL;
@@ -637,10 +624,7 @@ evdev_device_create(struct libinput_seat *seat,
 	device->dispatch = NULL;
 	device->fd = fd;
 	device->pending_event = EVDEV_NONE;
-
-	ioctl(device->fd, EVIOCGNAME(sizeof(devname)), devname);
-	devname[sizeof(devname) - 1] = '\0';
-	device->devname = strdup(devname);
+	device->devname = libevdev_get_name(device->evdev);
 
 	libinput_seat_ref(seat);
 
@@ -744,8 +728,7 @@ evdev_device_destroy(struct evdev_device *device)
 		dispatch->interface->destroy(dispatch);
 
 	libinput_seat_unref(device->base.seat);
-
-	free(device->devname);
+	libevdev_free(device->evdev);
 	free(device->devnode);
 	free(device->sysname);
 	free(device);

src/evdev.h

@@ -27,6 +27,7 @@
 #include "config.h"
 
 #include <linux/input.h>
+#include <libevdev/libevdev.h>
 
 #include "libinput-private.h"
 
@@ -55,10 +56,11 @@ struct evdev_device {
 	struct libinput_source *source;
 
 	struct evdev_dispatch *dispatch;
+	struct libevdev *evdev;
 	char *output_name;
 	char *devnode;
 	char *sysname;
-	char *devname;
+	const char *devname;
 	int fd;
 	struct {
 		int min_x, max_x, min_y, max_y;
@@ -86,16 +88,6 @@ struct evdev_device {
 	int is_mt;
 };
 
-/* copied from udev/extras/input_id/input_id.c */
-/* we must use this kernel-compatible implementation */
-#define BITS_PER_LONG (sizeof(unsigned long) * 8)
-#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
-#define OFF(x)  ((x)%BITS_PER_LONG)
-#define BIT(x)  (1UL<<OFF(x))
-#define LONG(x) ((x)/BITS_PER_LONG)
-#define TEST_BIT(array, bit)    ((array[LONG(bit)] >> OFF(bit)) & 1)
-/* end copied */
-
 #define EVDEV_UNHANDLED_DEVICE ((struct evdev_device *) 1)
 
 struct evdev_dispatch;