#include "config.h"
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <math.h>
#include <poll.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libevdev/libevdev.h"
#define min(a, b) (((a) < (b)) ? (a) : (b))
#define max(a, b) (((a) > (b)) ? (a) : (b))
static int signalled = 0;
static int
usage(const char *progname) {
printf("Usage: %s 12x34 /dev/input/eventX\n", progname);
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"
"The first argument is the physical size of the touchpad in mm (WIDTHxHEIGHT).\n");
return 1;
}
struct dimensions {
int top, bottom, left, right;
};
struct size {
int w, h;
};
static int
print_current_values(const struct dimensions *d)
{
static int progress;
char status = 0;
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);
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 void
signal_handler(__attribute__((__unused__)) int signal)
{
signalled++;
}
static int
mainloop(struct libevdev *dev, struct dimensions *dim) {
struct pollfd fds;
fds.fd = libevdev_get_fd(dev);
fds.events = POLLIN;
signal(SIGINT, signal_handler);
while (poll(&fds, 1, -1)) {
struct input_event ev;
int rc;
if (signalled)
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;
}
if (rc != -EAGAIN && rc < 0) {
fprintf(stderr, "Error: %s\n", strerror(-rc));
return 1;
}
if (rc == LIBEVDEV_READ_STATUS_SUCCESS)
handle_event(dim, &ev);
} while (rc != -EAGAIN);
}
return 0;
}
static inline void
pid_vid_matchstr(struct libevdev *dev, char *match, size_t sz)
{
snprintf(match, sz, "input:b%04Xv%04Xp%04X",
libevdev_get_id_bustype(dev),
libevdev_get_id_vendor(dev),
libevdev_get_id_product(dev));
}
static inline void
dmi_matchstr(struct libevdev *dev, char *match, size_t sz)
{
char modalias[PATH_MAX];
FILE *fp;
fp = fopen("/sys/class/dmi/id/modalias", "r");
if (!fp || fgets(modalias, sizeof(modalias), fp) == NULL) {
sprintf(match, "ERROR READING DMI MODALIAS");
if (fp)
fclose(fp);
return;
}
fclose(fp);
modalias[strlen(modalias) - 1] = '\0';
snprintf(match, sz, "name:%s:%s", libevdev_get_name(dev), modalias);
}
static void
print_udev_override_rule(struct libevdev *dev,
const struct dimensions *dim,
const struct size *size) {
const struct input_absinfo *x, *y;
char match[PATH_MAX];
int w, h;
int xres, yres;
x = libevdev_get_abs_info(dev, ABS_X);
y = libevdev_get_abs_info(dev, ABS_Y);
w = dim->right - dim->left;
h = dim->bottom - dim->top;
xres = round((double)w/size->w);
yres = round((double)h/size->h);
if (x->resolution && y->resolution) {
int width = x->maximum - x->minimum,
height = y->maximum - y->minimum;
printf("Touchpad size as listed by the kernel: %dx%dmm\n",
width/x->resolution, height/y->resolution);
} else {
printf("Touchpad has no resolution, size unknown\n");
}
printf("User-specified touchpad size: %dx%dmm\n", size->w, size->h);
printf("Calculated ranges: %d/%d\n", w, h);
printf("\n");
printf("Suggested udev rule:\n");
switch(libevdev_get_id_bustype(dev)) {
case BUS_USB:
case BUS_BLUETOOTH:
pid_vid_matchstr(dev, match, sizeof(match));
break;
default:
dmi_matchstr(dev, match, sizeof(match));
break;
}
printf("# <Laptop model description goes here>\n"
"evdev:%s*\n"
" EVDEV_ABS_00=%d:%d:%d\n"
" EVDEV_ABS_01=%d:%d:%d\n",
match,
dim->left, dim->right, xres,
dim->top, dim->bottom, yres);
if (libevdev_has_event_code(dev, EV_ABS, ABS_MT_POSITION_X))
printf(" EVDEV_ABS_35=%d:%d:%d\n"
" EVDEV_ABS_36=%d:%d:%d\n",
dim->left, dim->right, xres,
dim->top, dim->bottom, yres);
}
int main (int argc, char **argv) {
int rc;
int fd;
const char *path;
struct libevdev *dev;
struct dimensions dim;
struct size size;
if (argc < 3)
return usage(basename(argv[0]));
if (sscanf(argv[1], "%dx%d", &size.w, &size.h) != 2 ||
size.w <= 0 || size.h <= 0)
return usage(basename(argv[0]));
if (size.w < 30 || size.h < 30) {
fprintf(stderr,
"%dx%dmm is too small for a touchpad.\n"
"Please specify the touchpad size in mm.\n",
size.w, size.h);
return 1;
}
path = argv[2];
if (path[0] == '-')
return usage(basename(argv[0]));
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);
if (!libevdev_has_event_code(dev, EV_ABS, ABS_X) ||
!libevdev_has_event_code(dev, EV_ABS, ABS_Y)) {
fprintf(stderr, "Error: this device does not have abs axes\n");
rc = EXIT_FAILURE;
goto out;
}
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\n");
print_udev_override_rule(dev, &dim, &size);
out:
libevdev_free(dev);
close(fd);
return rc;
}