libinput/udev/libinput-model-quirks.c
Peter Hutterer 1523d8bb2e Extract and reset the abs fuzz value for the x/y axes
The kernel fuzz handling is buggy, especially when we want to rely on the fuzz
value for our hysteresis. But since this is a hw property and (at least
sometimes) set by the driver, we can't make this a pure libinput hwdb set
either.

So our workaround is:
* extract the (non-zero) fuzz into a udev property so we don't lose it
* set the fuzz to 0 to disable the in-kernel hysteresis
* overwrite our internal absinfo with the property fuzz

This way we get to use the hw-specified fuzz without having the kernel muck
around with it. We also get to use the EVDEV_ABS_ values in 60-evdev.hwdb to
override a driver-set fuzz.

Two drawbacks:
- we're resetting the kernel fuzz to 0, this affects any other users of the
  device node. That's probably a minor impact only.
- we can only save this in a udev property there's a risk of this information
  getting lost when playing around with udev rules. That too should be a minor
  issue.

https://bugs.freedesktop.org/show_bug.cgi?id=105303

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2018-03-09 09:49:54 +10:00

200 lines
4.5 KiB
C

/*
* Copyright © 2015 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include "config.h"
#include <fcntl.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libudev.h>
#include <linux/input.h>
#include <libevdev/libevdev.h>
#include "libinput-util.h"
static inline const char *
prop_value(struct udev_device *device,
const char *prop_name)
{
struct udev_device *parent;
const char *prop_value = NULL;
parent = device;
while (parent && !prop_value) {
prop_value = udev_device_get_property_value(parent, prop_name);
parent = udev_device_get_parent(parent);
}
return prop_value;
}
static void
handle_touchpad_alps(struct udev_device *device)
{
const char *product;
int bus, vid, pid, version;
product = prop_value(device, "PRODUCT");
if (!product)
return;
if (sscanf(product, "%x/%x/%x/%x", &bus, &vid, &pid, &version) != 4)
return;
/* ALPS' firmware version is the version */
if (version)
printf("LIBINPUT_MODEL_FIRMWARE_VERSION=%x\n", version);
}
static void
handle_touchpad_synaptics(struct udev_device *device)
{
const char *product, *props;
int bus, vid, pid, version;
int prop;
product = prop_value(device, "PRODUCT");
if (!product)
return;
if (sscanf(product, "%x/%x/%x/%x", &bus, &vid, &pid, &version) != 4)
return;
if (bus != BUS_I8042 || vid != 0x2 || pid != 0x7)
return;
props = prop_value(device, "PROP");
if (sscanf(props, "%x", &prop) != 1)
return;
if (prop & (1 << INPUT_PROP_SEMI_MT))
printf("LIBINPUT_MODEL_JUMPING_SEMI_MT=1\n");
}
static void
handle_touchpad(struct udev_device *device)
{
const char *name = NULL;
name = prop_value(device, "NAME");
if (!name)
return;
if (strstr(name, "AlpsPS/2 ALPS") != NULL)
handle_touchpad_alps(device);
if (strstr(name, "Synaptics ") != NULL)
handle_touchpad_synaptics(device);
}
/**
* For a non-zero fuzz on the x/y axes, print that fuzz as property and
* reset the kernel's fuzz to 0.
* https://bugs.freedesktop.org/show_bug.cgi?id=105202
*/
static void
handle_absfuzz(struct udev_device *device)
{
const char *devnode;
struct libevdev *evdev = NULL;
int fd = -1;
int rc;
unsigned int *code;
unsigned int axes[] = {ABS_X,
ABS_Y,
ABS_MT_POSITION_X,
ABS_MT_POSITION_Y};
devnode = udev_device_get_devnode(device);
if (!devnode)
goto out;
fd = open(devnode, O_RDWR);
if (fd == -1 && errno == EACCES)
fd = open(devnode, O_RDONLY);
if (fd < 0)
goto out;
rc = libevdev_new_from_fd(fd, &evdev);
if (rc != 0)
goto out;
if (!libevdev_has_event_type(evdev, EV_ABS))
goto out;
ARRAY_FOR_EACH(axes, code) {
struct input_absinfo abs;
int fuzz;
fuzz = libevdev_get_abs_fuzz(evdev, *code);
if (!fuzz)
continue;
abs = *libevdev_get_abs_info(evdev, *code);
abs.fuzz = 0;
libevdev_kernel_set_abs_info(evdev, *code, &abs);
printf("LIBINPUT_FUZZ_%02x=%d\n", *code, fuzz);
}
out:
close(fd);
libevdev_free(evdev);
}
int main(int argc, char **argv)
{
int rc = 1;
struct udev *udev = NULL;
struct udev_device *device = NULL;
const char *syspath;
if (argc != 2)
return 1;
syspath = argv[1];
udev = udev_new();
if (!udev)
goto out;
device = udev_device_new_from_syspath(udev, syspath);
if (!device)
goto out;
handle_absfuzz(device);
if (prop_value(device, "ID_INPUT_TOUCHPAD"))
handle_touchpad(device);
rc = 0;
out:
if (device)
udev_device_unref(device);
if (udev)
udev_unref(udev);
return rc;
}