tools: add a tool to print the actual range provided by a touchpad

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

tools/.gitignore

@@ -1 +1,2 @@
 libevdev-events
+touchpad-edge-detector

tools/Makefile.am

@@ -1,4 +1,5 @@
 noinst_PROGRAMS = libevdev-events
+bin_PROGRAMS = touchpad-edge-detector
 
 AM_CPPFLAGS = $(GCC_CFLAGS) -I$(top_srcdir)/include -I$(top_srcdir)/libevdev
 libevdev_ldadd = $(top_builddir)/libevdev/libevdev.la
@@ -6,3 +7,6 @@ libevdev_ldadd = $(top_builddir)/libevdev/libevdev.la
 libevdev_events_SOURCES = libevdev-events.c
 libevdev_events_LDADD = $(libevdev_ldadd)
 
+touchpad_edge_detector_SOURCES = touchpad-edge-detector.c
+touchpad_edge_detector_LDADD = $(libevdev_ldadd)
+

tools/touchpad-edge-detector.c

@@ -0,0 +1,196 @@
+/*
+ * Copyright © 2014 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of Red Hat
+ * not be used in advertising or publicity pertaining to distribution
+ * of the software without specific, written prior permission.  Red
+ * Hat makes no representations about the suitability of this software
+ * for any purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+ * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <libevdev/libevdev.h>
+#include <sys/signalfd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+#define max(a, b) (((a) > (b)) ? (a) : (b))
+
+static int
+usage(void) {
+	printf("Usage: %s /dev/input/event0\n", program_invocation_short_name);
+	printf("\n");
+	printf("This tool reads the touchpad events from the kernel and calculates\n "
+	       "the minimum and maximum for the x and y coordinates, respectively.\n");
+	return 1;
+}
+
+struct dimensions {
+	int top, bottom, left, right;
+};
+
+static int
+print_current_values(const struct dimensions *d)
+{
+	static int progress;
+	char status;
+
+	switch (progress) {
+		case 0: status = '|'; break;
+		case 1: status = '/'; break;
+		case 2: status = '-'; break;
+		case 3: status = '\\'; break;
+	}
+
+	progress = (progress + 1) % 4;
+
+	printf("\rTouchpad sends:	x [%d..%d], y [%d..%d] %c",
+			d->left, d->right, d->top, d->bottom, status);
+	return 0;
+}
+
+static int
+handle_event(struct dimensions *d, const struct input_event *ev) {
+	if (ev->type == EV_SYN) {
+		return print_current_values(d);
+	} else if (ev->type != EV_ABS)
+		return 0;
+
+	switch(ev->code) {
+		case ABS_X:
+		case ABS_MT_POSITION_X:
+			d->left = min(d->left, ev->value);
+			d->right = max(d->right, ev->value);
+			break;
+		case ABS_Y:
+		case ABS_MT_POSITION_Y:
+			d->top = min(d->top, ev->value);
+			d->bottom = max(d->bottom, ev->value);
+			break;
+	}
+
+	return 0;
+}
+
+static int
+mainloop(struct libevdev *dev, struct dimensions *dim) {
+	struct pollfd fds[2];
+	sigset_t mask;
+
+	fds[0].fd = libevdev_get_fd(dev);
+	fds[0].events = POLLIN;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGINT);
+	fds[1].fd = signalfd(-1, &mask, SFD_NONBLOCK);
+	fds[1].events = POLLIN;
+
+	sigprocmask(SIG_BLOCK, &mask, NULL);
+
+	while (poll(fds, 2, -1)) {
+		struct input_event ev;
+		int rc;
+
+		if (fds[1].revents)
+			break;
+
+		do {
+			rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, &ev);
+			if (rc == LIBEVDEV_READ_STATUS_SYNC) {
+				fprintf(stderr, "Error: cannot keep up\n");
+				return 1;
+			} else if (rc != -EAGAIN && rc < 0) {
+				fprintf(stderr, "Error: %s\n", strerror(-rc));
+				return 1;
+			} else if (rc == LIBEVDEV_READ_STATUS_SUCCESS) {
+				handle_event(dim, &ev);
+			}
+		} while (rc != -EAGAIN);
+	}
+
+	return 0;
+}
+
+int main (int argc, char **argv) {
+	int rc;
+	int fd;
+	const char *path;
+	struct libevdev *dev;
+	struct dimensions dim;
+
+	if (argc < 2)
+		return usage();
+
+	path = argv[1];
+	if (path[0] == '-')
+		return usage();
+
+	fd = open(path, O_RDONLY|O_NONBLOCK);
+	if (fd < 0) {
+		fprintf(stderr, "Error opening the device: %s\n", strerror(errno));
+		return 1;
+	}
+
+	rc = libevdev_new_from_fd(fd, &dev);
+	if (rc != 0) {
+		fprintf(stderr, "Error fetching the device info: %s\n", strerror(-rc));
+		return 1;
+	}
+
+	if (libevdev_grab(dev, LIBEVDEV_GRAB) != 0) {
+		fprintf(stderr, "Error: cannot grab the device, something else is grabbing it.\n");
+		fprintf(stderr, "Use 'fuser -v %s' to find processes with an open fd\n", path);
+		return 1;
+	}
+	libevdev_grab(dev, LIBEVDEV_UNGRAB);
+
+	dim.left = INT_MAX;
+	dim.right = INT_MIN;
+	dim.top = INT_MAX;
+	dim.bottom = INT_MIN;
+
+	printf("Touchpad %s on %s\n", libevdev_get_name(dev), path);
+	printf("Move one finger around the touchpad to detect the actual edges\n");
+	printf("Kernel says:	x [%d..%d], y [%d..%d]\n",
+			libevdev_get_abs_minimum(dev, ABS_X),
+			libevdev_get_abs_maximum(dev, ABS_X),
+			libevdev_get_abs_minimum(dev, ABS_Y),
+			libevdev_get_abs_maximum(dev, ABS_Y));
+
+	setbuf(stdout, NULL);
+
+	rc = mainloop(dev, &dim);
+
+	printf("\n");
+
+	libevdev_free(dev);
+	close(fd);
+
+	return rc;
+}
+