[PATCH libevdev] tools: add a tool to change kernel devices
Peter Hutterer
peter.hutterer at who-t.net
Tue Jan 6 14:19:56 PST 2015
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
I needed this to manually change the resolution on uinput devices for tests, so I
figured let's make it a bit more generic. Not a lot of error checking is
performed, we can do this later if needed. For now it's pretty much assumed
that you know what you're doing when you're running this.
tools/.gitignore | 1 +
tools/Makefile.am | 7 +-
tools/libevdev-tweak-device.1 | 59 ++++++++++
tools/libevdev-tweak-device.c | 255 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 321 insertions(+), 1 deletion(-)
create mode 100644 tools/libevdev-tweak-device.1
create mode 100644 tools/libevdev-tweak-device.c
diff --git a/tools/.gitignore b/tools/.gitignore
index 292c08e..c2a2645 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -1,3 +1,4 @@
libevdev-events
touchpad-edge-detector
mouse-dpi-tool
+libevdev-tweak-device
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 8e3950d..d699c5c 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -1,7 +1,8 @@
noinst_PROGRAMS = libevdev-events
bin_PROGRAMS = \
touchpad-edge-detector \
- mouse-dpi-tool
+ mouse-dpi-tool \
+ libevdev-tweak-device
AM_CPPFLAGS = $(GCC_CFLAGS) -I$(top_srcdir) -I$(top_srcdir)/include -I$(top_srcdir)/libevdev
libevdev_ldadd = $(top_builddir)/libevdev/libevdev.la
@@ -14,3 +15,7 @@ touchpad_edge_detector_LDADD = $(libevdev_ldadd)
mouse_dpi_tool_SOURCES = mouse-dpi-tool.c
mouse_dpi_tool_LDADD = $(libevdev_ldadd)
+
+libevdev_tweak_device_SOURCES = libevdev-tweak-device.c
+libevdev_tweak_device_LDADD = $(libevdev_ldadd)
+libevdev_tweak_device_MANS = libevdev-tweak-device.1
diff --git a/tools/libevdev-tweak-device.1 b/tools/libevdev-tweak-device.1
new file mode 100644
index 0000000..0d2c1ac
--- /dev/null
+++ b/tools/libevdev-tweak-device.1
@@ -0,0 +1,59 @@
+.TH LIBEVDEV-TWEAK-DEVICE "1"
+.SH NAME
+libevdev-tweak-device \- modify an evdev kernel device
+.SH SYNOPSIS
+.B libevdev-tweak-device
+--abs ABS_X [--min a] [--max b] [--res c] [--fuzz d] [--flat e]
+/dev/input/eventX
+.PP
+.B libevdev-tweak-device
+--led LED_NUML --on|--off /dev/input/eventX
+.SH DESCRIPTION
+.PP
+The
+.I libevdev-tweak-device
+tool changes the properties of the evdev kernel device at
+.I /dev/input/eventX.
+Currently this may be used to force an LED on or off, or to change the
+properties of an absolute axis (e.g. its minimum/maximum range or
+resolution). Changes are permanent until the device is removed.
+.SH OPTIONS
+.SS Changing absolute axes
+.TP 8
+.B --abs axis
+Change the given named ABS_ kernel axis, e.g. ABS_X. For a full list, see linux/input.h.
+Each of the options
+.B min, max, res, fuzz, flat
+may be given.
+.TP 8
+.B --min v
+Set the absinfo minimum to the value v
+.TP 8
+.B --max v
+Set the absinfo maximum to the value v
+.TP 8
+.B --res v
+Set the absinfo resolution to the value v
+.TP 8
+.B --fuzz v
+Set the absinfo fuzz to the value v
+.TP 8
+.B --flat v
+Set the absinfo flat to the value v
+.PP
+.SS Toggling LEDs
+.TP 8
+.B --led led
+Change the given LED, e.g. LED_NUML. For a full list, see linux/input.h.
+.TP 8
+.B --on
+Change the LED state to on
+.TP 8
+.B --off
+Change the LED state to off
+.SH NOTES
+.PP
+The kernel does not notify processes about absinfo property changes. Any
+process that has previously obtained the absinfo from the device will remain
+on the old information. This makes using this tool potentially racy, use
+with caution.
diff --git a/tools/libevdev-tweak-device.c b/tools/libevdev-tweak-device.c
new file mode 100644
index 0000000..a482d12
--- /dev/null
+++ b/tools/libevdev-tweak-device.c
@@ -0,0 +1,255 @@
+/*
+ * 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 the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS 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.
+ */
+
+#define _GNU_SOURCE
+#include <config.h>
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <linux/input.h>
+
+#include "libevdev.h"
+
+static unsigned int changes; /* bitmask of changes */
+static struct input_absinfo absinfo;
+static int axis;
+static int led;
+static int led_state = -1;
+const char *path;
+
+static void
+usage(void)
+{
+ printf("%s --abs <axis> [--min min] [--max max] [--res res] [--fuzz fuzz] [--flat flat] /dev/input/eventXYZ\n"
+ "\tChange the absinfo struct for the named axis\n"
+ "%s --led <led> --on|--off /dev/input/eventXYZ\n"
+ "\tEnable or disable the named LED\n",
+ program_invocation_short_name, program_invocation_short_name);
+}
+
+enum opts {
+ OPT_ABS = 1 << 0,
+ OPT_MIN = 1 << 1,
+ OPT_MAX = 1 << 2,
+ OPT_FUZZ = 1 << 3,
+ OPT_FLAT = 1 << 4,
+ OPT_RES = 1 << 5,
+ OPT_LED = 1 << 6,
+ OPT_ON = 1 << 7,
+ OPT_OFF = 1 << 8,
+ OPT_HELP = 1 << 9,
+};
+
+static int
+parse_options(int argc, char **argv)
+{
+ int rc = 1;
+ int c;
+ int option_index = 0;
+ static struct option opts[] = {
+ { "abs", 1, 0, OPT_ABS },
+ { "min", 1, 0, OPT_MIN },
+ { "max", 1, 0, OPT_MAX },
+ { "fuzz", 1, 0, OPT_FUZZ },
+ { "flat", 1, 0, OPT_FLAT },
+ { "res", 1, 0, OPT_RES },
+ { "led", 1, 0, OPT_LED },
+ { "on", 0, 0, OPT_ON },
+ { "off", 0, 0, OPT_OFF },
+ { "help", 0, 0, OPT_HELP },
+ { NULL, 0, 0, 0 },
+ };
+
+ if (argc < 2)
+ goto error;
+
+ while (1) {
+ c = getopt_long(argc, argv, "h", opts, &option_index);
+ if (c == -1)
+ break;
+
+ switch (c) {
+ case 'h':
+ case OPT_HELP:
+ goto error;
+ case OPT_ABS:
+ if (changes & OPT_LED)
+ goto error;
+
+ axis = libevdev_event_code_from_name(EV_ABS,
+ optarg);
+ if (axis == -1)
+ goto error;
+ break;
+ case OPT_LED:
+ if (changes & OPT_ABS)
+ goto error;
+
+ led = libevdev_event_code_from_name(EV_LED,
+ optarg);
+ if (led == -1)
+ goto error;
+ break;
+ case OPT_MIN:
+ absinfo.minimum = atoi(optarg);
+ break;
+ case OPT_MAX:
+ absinfo.maximum = atoi(optarg);
+ break;
+ case OPT_FUZZ:
+ absinfo.fuzz = atoi(optarg);
+ break;
+ case OPT_FLAT:
+ absinfo.flat = atoi(optarg);
+ break;
+ case OPT_RES:
+ absinfo.resolution = atoi(optarg);
+ break;
+ case OPT_ON:
+ if (led_state != -1)
+ goto error;
+ led_state = 1;
+ break;
+ case OPT_OFF:
+ if (led_state != -1)
+ goto error;
+ led_state = 0;
+ break;
+ default:
+ goto error;
+ }
+ changes |= c;
+ }
+
+ if (optind >= argc)
+ goto error;
+ path = argv[optind];
+
+ rc = 0;
+error:
+ return rc;
+}
+
+static void
+set_abs(struct libevdev *dev)
+{
+ int rc;
+ struct input_absinfo abs;
+ const struct input_absinfo *a;
+
+ if ((a = libevdev_get_abs_info(dev, axis)) == NULL) {
+ fprintf(stderr,
+ "Device '%s' doesn't have axis %s\n",
+ libevdev_get_name(dev),
+ libevdev_event_code_get_name(EV_ABS, axis));
+ return;
+ }
+
+ abs = *a;
+ if (changes & OPT_MIN)
+ abs.minimum = absinfo.minimum;
+ if (changes & OPT_MAX)
+ abs.maximum = absinfo.maximum;
+ if (changes & OPT_FUZZ)
+ abs.fuzz = absinfo.fuzz;
+ if (changes & OPT_FLAT)
+ abs.flat = absinfo.flat;
+ if (changes & OPT_RES)
+ abs.resolution = absinfo.resolution;
+
+ rc = libevdev_kernel_set_abs_info(dev, axis, &abs);
+ if (rc != 0)
+ fprintf(stderr,
+ "Failed to set absinfo %s: %s",
+ libevdev_event_code_get_name(EV_ABS, axis),
+ strerror(-rc));
+}
+
+static void
+set_led(struct libevdev *dev)
+{
+ int rc;
+ enum libevdev_led_value state =
+ led_state ? LIBEVDEV_LED_ON : LIBEVDEV_LED_OFF;
+
+ if (!libevdev_has_event_code(dev, EV_LED, led)) {
+ fprintf(stderr,
+ "Device '%s' doesn't have %s\n",
+ libevdev_get_name(dev),
+ libevdev_event_code_get_name(EV_LED, axis));
+ return;
+ }
+
+
+ rc = libevdev_kernel_set_led_value(dev, led, state);
+ if (rc != 0)
+ fprintf(stderr,
+ "Failed to set LED %s: %s",
+ libevdev_event_code_get_name(EV_LED, led),
+ strerror(-rc));
+}
+
+int
+main(int argc, char **argv)
+{
+ struct libevdev *dev = NULL;
+ int fd;
+ int rc = 1;
+
+ rc = parse_options(argc, argv);
+ if (rc != 0 || !path) {
+ usage();
+ goto out;
+ }
+
+ fd = open(path, O_RDWR);
+ if (fd < 0) {
+ perror("Failed to open device");
+ goto out;
+ }
+
+ rc = libevdev_new_from_fd(fd, &dev);
+ if (rc < 0) {
+ fprintf(stderr, "Failed to init libevdev (%s)\n", strerror(-rc));
+ goto out;
+ }
+
+ if (changes & OPT_ABS)
+ set_abs(dev);
+ else if (changes & OPT_LED)
+ set_led(dev);
+ else
+ fprintf(stderr,
+ "++?????++ Out of Cheese Error. Redo From Start.\n");
+
+out:
+ libevdev_free(dev);
+
+ return rc;
+}
--
2.1.0
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