2 * Copyright © 2013 Red Hat, Inc.
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
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8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
27 #include <linux/input.h>
32 ER_SINGLE = 1, /**< Read until including the first EV_SYN or EAGAIN */
33 ER_SYNC = 2, /**< Process data in sync mode */
34 ER_ALL = 4, /**< Read until EAGAIN */
39 * Initialize a new libevdev struct.
41 * @param fd If fd >= 0, the device is initialised for the fd. Otherwise, a
42 * caller must call evdev_set_fd() before attempting to read events.
44 * @see libevdev_set_fd
46 struct libevdev* libevdev_new(int fd);
49 * Clean up and free the libevdev struct.
51 * @note This function may be called before libevdev_set_fd.
53 void libevdev_free(struct libevdev *dev);
56 * Logging function called by library-internal logging.
57 * This function is expected to treat it's input like printf would.
59 * @param format printf-style format string
60 * @param args List of arguments
62 * @see libevdev_set_log_handler
64 typedef void (*libevdev_log_func_t)(const char *format, va_list args);
67 * Set a printf-style logging handler for library-internal logging.
69 * @note This function may be called before libevdev_set_fd.
71 void libevdev_set_log_handler(struct libevdev *dev, libevdev_log_func_t logfunc);
74 * Grab or ungrab the device through a kernel EVIOCGRAB. This prevents other
75 * clients (including kernel-internal ones such as rfkill) from receiving
76 * events from this device.
78 * This is generally a bad idea. Don't do this.
80 * Grabbing an already grabbed device, or ungrabbing an ungrabbed device is
81 * a noop and always succeeds.
83 * @param grab If true, grab the device. Otherwise ungrab the device.
85 * @return 0 if the device was successfull grabbed or ungrabbed, or a
86 * negative errno in case of failure.
88 int libevdev_grab(struct libevdev *dev, int grab);
91 * Set the fd for this struct and initialize internal data.
92 * The fd must be open for reading and ioctl.
94 * This function may only be called once per device. If you need to re-read
95 * a device, use libevdev_free and libevdev_new. If you need to change the
96 * fd, use libevdev_change_fd.
98 * Unless otherwise specified, libevdev function behavior is undefined until
99 * a successfull call to libevdev_set_fd.
101 * @param fd The file descriptor for the device
103 * @return 0 on success, or a negative error code on failure
105 * @see libevdev_change_fd
109 int libevdev_set_fd(struct libevdev* dev, int fd);
112 * Change the fd for this device, without re-reading the actual device.
114 * It is an error to call this function before calling libevdev_set_fd.
116 * @param fd The new fd
118 * @return 0 on success, or -1 on failure.
120 * @see libevdev_set_fd
122 int libevdev_change_fd(struct libevdev* dev, int fd);
126 * @return The previously set fd, or -1 if none had been set previously.
127 * @note This function may be called before libevdev_set_fd.
129 int libevdev_get_fd(const struct libevdev* dev);
132 * Get the next event from the device.
134 * In normal mode, this function returns 0 and returns the event in the
135 * parameter ev. If no events are available at this time, it returns -EAGAIN
136 * and ev is undefined.
138 * If a SYN_DROPPED is read from the device, this function returns 1. The
139 * caller should now call this function with the ER_SYNC flag set, to get
140 * the set of events that make up the device state diff. This function
141 * returns 1 for each event part of that diff, until it returns -EAGAIN once
142 * all events have been synced.
144 * If a device needs to be synced by the caller but the caller does not call
145 * with the ER_SYNC flag set, all events from the diff are dropped and event
146 * processing continues as normal.
148 * @return On failure, a negative errno is returned.
149 * @retval 0 One or more events where read of the device
150 * @retval -EAGAIN No events are currently available on the device
151 * @retval 1 A SYN_DROPPED event was received, or a synced event was
154 * @note This function is signal-safe.
156 int libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event *ev);
159 * @return The device name as read off the kernel device
161 * @note This function is signal-safe.
163 const char* libevdev_get_name(const struct libevdev *dev);
166 * @return The device's product ID
168 * @note This function is signal-safe.
170 int libevdev_get_pid(const struct libevdev *dev);
172 * @return The device's vendor ID
174 * @note This function is signal-safe.
176 int libevdev_get_vid(const struct libevdev *dev);
179 * @return The device's bus type
181 * @note This function is signal-safe.
183 int libevdev_get_bustype(const struct libevdev *dev);
186 * @return 1 if the device supports this event type, or 0 otherwise.
188 * @note This function is signal-safe
190 int libevdev_has_property(const struct libevdev *dev, unsigned int prop);
193 * @return 1 if the device supports this event type, or 0 otherwise.
195 * @note This function is signal-safe.
197 int libevdev_has_event_type(const struct libevdev *dev, unsigned int type);
200 * @return 1 if the device supports this event type, or 0 otherwise.
202 * @note This function is signal-safe.
204 int libevdev_has_event_code(const struct libevdev *dev, unsigned int type, unsigned int code);
207 * @return axis minimum for the given axis or 0 if the axis is invalid
209 int libevdev_get_abs_min(const struct libevdev *dev, unsigned int code);
211 * @return axis maximum for the given axis or 0 if the axis is invalid
213 int libevdev_get_abs_max(const struct libevdev *dev, unsigned int code);
215 * @return axis fuzz for the given axis or 0 if the axis is invalid
217 int libevdev_get_abs_fuzz(const struct libevdev *dev, unsigned int code);
219 * @return axis flat for the given axis or 0 if the axis is invalid
221 int libevdev_get_abs_flat(const struct libevdev *dev, unsigned int code);
223 * @return axis resolution for the given axis or 0 if the axis is invalid
225 int libevdev_get_abs_resolution(const struct libevdev *dev, unsigned int code);
228 * @return The input_absinfo for the given code, or NULL if the device does
229 * not support this event code.
231 const struct input_absinfo* libevdev_get_abs_info(const struct libevdev *dev, unsigned int code);
234 * Behaviour of this function is undefined if the device does not provide
237 * @return The current value of the event.
239 * @note This function is signal-safe.
240 * @note The value for ABS_MT_ events is undefined, use
241 * libevdev_get_slot_value instead
243 * @see libevdev_get_slot_value
245 int libevdev_get_event_value(const struct libevdev *dev, unsigned int type, unsigned int code);
248 * Fetch the current value of the event type. This is a shortcut for
251 * if (libevdev_has_event_type(dev, t) && libevdev_has_event_code(dev, t, c))
252 * val = libevdev_get_event_value(dev, t, c);
255 * @return non-zero if the device supports this event code, or zero
256 * otherwise. On return of zero, value is unmodified.
258 * @note This function is signal-safe.
259 * @note The value for ABS_MT_ events is undefined, use
260 * libevdev_fetch_slot_value instead
262 * @see libevdev_fetch_slot_value
264 int libevdev_fetch_event_value(const struct libevdev *dev, unsigned int type, unsigned int code, int *value);
267 * Return the current value of the code for the given slot.
269 * The return value is undefined for a slot exceeding the available slots on
270 * the device, or for a device that does not have slots.
272 * @note This function is signal-safe.
273 * @note The value for events other than ABS_MT_ is undefined, use
274 * libevdev_fetch_value instead
276 * @see libevdev_get_value
278 int libevdev_get_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code);
281 * Fetch the current value of the code for the given slot. This is a shortcut for
284 * if (libevdev_has_event_type(dev, EV_ABS) &&
285 * libevdev_has_event_code(dev, EV_ABS, c) &&
286 * slot < device->number_of_slots)
287 * val = libevdev_get_slot_value(dev, slot, c);
290 * @return non-zero if the device supports this event code, or zero
291 * otherwise. On return of zero, value is unmodified.
293 * @note This function is signal-safe.
294 * @note The value for ABS_MT_ events is undefined, use
295 * libevdev_fetch_slot_value instead
297 * @see libevdev_fetch_slot_value
299 int libevdev_fetch_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code, int *value);
302 * Get the number of slots supported by this device.
304 * Note that the slot offset may be non-zero, use libevdev_get_abs_min() or
305 * libevdev_get_abs_info() to get the minimum slot number.
307 * @return The number of slots supported, or -1
309 int libevdev_get_num_slots(const struct libevdev *dev);
312 * Get the currently active slot. This may differ from the value
313 * an ioctl may return at this time as events may have been read off the fd
314 * since changing the slot value but those events are still in the buffer
315 * waiting to be processed. The returned value is the value a caller would
316 * see if it were to process events manually one-by-one.
318 * @return the currently active slot (logically)
320 int libevdev_get_current_slot(const struct libevdev *dev);
323 * Forcibly enable an event type on this device, even if the underlying
324 * device does not support it. While this cannot make the device actually
325 * report such events, it will now return true for libevdev_has_event_type.
327 * This is a local modification only affecting only this process and only
330 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
332 * @return 0 on success or -1 otherwise
334 * @see libevdev_has_event_type
336 int libevdev_enable_event_type(struct libevdev *dev, unsigned int type);
339 * Forcibly disable an event type on this device, even if the underlying
340 * device provides it, effectively muting all keys or axes. libevdev will
341 * filter any events matching this type and none will reach the caller.
342 * libevdev_has_event_type will return false for this type.
344 * In most cases, a caller likely only wants to disable a single code, not
345 * the whole type. Use libevdev_disable_event_code for that.
347 * This is a local modification only affecting only this process and only
350 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
352 * @return 0 on success or -1 otherwise
354 * @see libevdev_has_event_type
355 * @see libevdev_disable_event_type
357 int libevdev_disable_event_type(struct libevdev *dev, unsigned int type);
360 * Forcibly enable an event type on this device, even if the underlying
361 * device does not support it. While this cannot make the device actually
362 * report such events, it will now return true for libevdev_has_event_code.
364 * The last argument depends on the type and code:
365 * - If type is EV_ABS, the vararg must be a pointer to a struct input_absinfo
366 * containing the data for this axis.
367 * - For all other types, the argument is ignored.
369 * This function calls libevdev_enable_event_type if necessary.
371 * This is a local modification only affecting only this process and only
374 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
375 * @param code The event code to enable (ABS_X, REL_X, etc.)
376 * @param data Axis/key data, depending on type and code
378 * @return 0 on success or -1 otherwise
380 * @see libevdev_enable_event_type
382 int libevdev_enable_event_code(struct libevdev *dev, unsigned int type, unsigned int code, const void *data);
385 * Forcibly disable an event code on this device, even if the underlying
386 * device provides it, effectively muting this key or axis. libevdev will
387 * filter any events matching this type and code and none will reach the
389 * libevdev_has_event_code will return false for this code combination.
391 * Disabling all event codes for a given type will not disable the event
392 * type. Use libevdev_disable_event_type for that.
394 * This is a local modification only affecting only this process and only
397 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
398 * @param code The event code to enable (ABS_X, REL_X, etc.)
400 * @return 0 on success or -1 otherwise
402 * @see libevdev_has_event_code
403 * @see libevdev_disable_event_type
405 int libevdev_disable_event_code(struct libevdev *dev, unsigned int type, unsigned int code);
408 * Set the device's EV_ABS/<code> axis to the value defined in the abs
409 * parameter. This will be written to the kernel.
411 * @return zero on success, or a negative errno on failure
413 * @see libevdev_enable_event_code
415 int libevdev_kernel_set_abs_value(struct libevdev *dev, unsigned int code, const struct input_absinfo *abs);
417 #endif /* libevdev_H */