evdev: parse LIBINPUT_ATTR_RESOLUTION_HINT

For Elantech touchpads, we know that the resolution is 31u/mm (800dpi) for
v1-v3 firmware. Set this as a hint until we get either the kernel or systemd
to set this for us.

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

diff --git a/src/evdev.c b/src/evdev.c
index 3d19ee7..a833de5 100644 (file)
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1552,6 +1552,23 @@ evdev_read_model(struct evdev_device *device)
 }
 
 static inline int
+evdev_read_attr_res_prop(struct evdev_device *device,
+                        size_t *xres,
+                        size_t *yres)
+{
+       struct udev_device *udev;
+       const char *res_prop;
+
+       udev = device->udev_device;
+       res_prop = udev_device_get_property_value(udev,
+                                                  "LIBINPUT_ATTR_RESOLUTION_HINT");
+       if (!res_prop)
+               return false;
+
+       return parse_dimension_property(res_prop, xres, yres);
+}
+
+static inline int
 evdev_read_attr_size_prop(struct evdev_device *device,
                          size_t *size_x,
                          size_t *size_y)
@@ -1578,8 +1595,8 @@ evdev_fix_abs_resolution(struct evdev_device *device,
        struct libevdev *evdev = device->evdev;
        const struct input_absinfo *absx, *absy;
        size_t widthmm = 0, heightmm = 0;
-       int xres = EVDEV_FAKE_RESOLUTION,
-           yres = EVDEV_FAKE_RESOLUTION;
+       size_t xres = EVDEV_FAKE_RESOLUTION,
+              yres = EVDEV_FAKE_RESOLUTION;
 
        if (!(xcode == ABS_X && ycode == ABS_Y)  &&
            !(xcode == ABS_MT_POSITION_X && ycode == ABS_MT_POSITION_Y)) {
@@ -1600,7 +1617,8 @@ evdev_fix_abs_resolution(struct evdev_device *device,
         * property is only for general size hints where we can make
         * educated guesses but don't know better.
         */
-       if (evdev_read_attr_size_prop(device, &widthmm, &heightmm)) {
+       if (!evdev_read_attr_res_prop(device, &xres, &yres) &&
+           evdev_read_attr_size_prop(device, &widthmm, &heightmm)) {
                xres = (absx->maximum - absx->minimum)/widthmm;
                yres = (absy->maximum - absy->minimum)/heightmm;
        }

diff --git a/udev/90-libinput-model-quirks.hwdb b/udev/90-libinput-model-quirks.hwdb
index 730b115..eec00b6 100644 (file)
--- a/udev/90-libinput-model-quirks.hwdb
+++ b/udev/90-libinput-model-quirks.hwdb
@@ -35,6 +35,12 @@ libinput:touchpad:input:b0005v05ACp*
  LIBINPUT_ATTR_SIZE_HINT=104x75
 
 ##########################################
+# Elantech
+##########################################
+libinput:name:*ETPS/2 Elantech Touchpad*:dmi:*
+ LIBINPUT_ATTR_RESOLUTION_HINT=31x31
+
+##########################################
 # Google
 ##########################################