2 * Copyright © 2013 Red Hat, Inc.
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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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19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
27 #include <linux/input.h>
32 LIBEVDEV_READ_SYNC = 1, /**< Process data in sync mode */
37 * Initialize a new libevdev struct.
39 * @param fd If fd >= 0, the device is initialised for the fd. Otherwise, a
40 * caller must call evdev_set_fd() before attempting to read events.
42 * @see libevdev_set_fd
44 struct libevdev* libevdev_new(int fd);
47 * Clean up and free the libevdev struct.
49 * @note This function may be called before libevdev_set_fd.
51 void libevdev_free(struct libevdev *dev);
54 * Logging function called by library-internal logging.
55 * This function is expected to treat it's input like printf would.
57 * @param format printf-style format string
58 * @param args List of arguments
60 * @see libevdev_set_log_handler
62 typedef void (*libevdev_log_func_t)(const char *format, va_list args);
65 * Set a printf-style logging handler for library-internal logging.
67 * @note This function may be called before libevdev_set_fd.
69 void libevdev_set_log_handler(struct libevdev *dev, libevdev_log_func_t logfunc);
72 * Grab or ungrab the device through a kernel EVIOCGRAB. This prevents other
73 * clients (including kernel-internal ones such as rfkill) from receiving
74 * events from this device.
76 * This is generally a bad idea. Don't do this.
78 * Grabbing an already grabbed device, or ungrabbing an ungrabbed device is
79 * a noop and always succeeds.
81 * @param grab If true, grab the device. Otherwise ungrab the device.
83 * @return 0 if the device was successfull grabbed or ungrabbed, or a
84 * negative errno in case of failure.
86 int libevdev_grab(struct libevdev *dev, int grab);
89 * Set the fd for this struct and initialize internal data.
90 * The fd must be open for reading and ioctl.
92 * This function may only be called once per device. If you need to re-read
93 * a device, use libevdev_free and libevdev_new. If you need to change the
94 * fd, use libevdev_change_fd.
96 * Unless otherwise specified, libevdev function behavior is undefined until
97 * a successfull call to libevdev_set_fd.
99 * @param fd The file descriptor for the device
101 * @return 0 on success, or a negative error code on failure
103 * @see libevdev_change_fd
107 int libevdev_set_fd(struct libevdev* dev, int fd);
110 * Change the fd for this device, without re-reading the actual device.
112 * It is an error to call this function before calling libevdev_set_fd.
114 * @param fd The new fd
116 * @return 0 on success, or -1 on failure.
118 * @see libevdev_set_fd
120 int libevdev_change_fd(struct libevdev* dev, int fd);
124 * @return The previously set fd, or -1 if none had been set previously.
125 * @note This function may be called before libevdev_set_fd.
127 int libevdev_get_fd(const struct libevdev* dev);
130 * Get the next event from the device.
132 * In normal mode, this function returns 0 and returns the event in the
133 * parameter ev. If no events are available at this time, it returns -EAGAIN
134 * and ev is undefined.
136 * If a SYN_DROPPED is read from the device, this function returns 1. The
137 * caller should now call this function with the ER_SYNC flag set, to get
138 * the set of events that make up the device state diff. This function
139 * returns 1 for each event part of that diff, until it returns -EAGAIN once
140 * all events have been synced.
142 * If a device needs to be synced by the caller but the caller does not call
143 * with the ER_SYNC flag set, all events from the diff are dropped and event
144 * processing continues as normal.
146 * @return On failure, a negative errno is returned.
147 * @retval 0 One or more events where read of the device
148 * @retval -EAGAIN No events are currently available on the device
149 * @retval 1 A SYN_DROPPED event was received, or a synced event was
152 * @note This function is signal-safe.
154 int libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event *ev);
157 * @return The device name as read off the kernel device
159 * @note This function is signal-safe.
161 const char* libevdev_get_name(const struct libevdev *dev);
164 * @return The device's product ID
166 * @note This function is signal-safe.
168 int libevdev_get_pid(const struct libevdev *dev);
170 * @return The device's vendor ID
172 * @note This function is signal-safe.
174 int libevdev_get_vid(const struct libevdev *dev);
177 * @return The device's bus type
179 * @note This function is signal-safe.
181 int libevdev_get_bustype(const struct libevdev *dev);
184 * @return 1 if the device supports this event type, or 0 otherwise.
186 * @note This function is signal-safe
188 int libevdev_has_property(const struct libevdev *dev, unsigned int prop);
191 * @return 1 if the device supports this event type, or 0 otherwise.
193 * @note This function is signal-safe.
195 int libevdev_has_event_type(const struct libevdev *dev, unsigned int type);
198 * @return 1 if the device supports this event type, or 0 otherwise.
200 * @note This function is signal-safe.
202 int libevdev_has_event_code(const struct libevdev *dev, unsigned int type, unsigned int code);
205 * @return axis minimum for the given axis or 0 if the axis is invalid
207 int libevdev_get_abs_min(const struct libevdev *dev, unsigned int code);
209 * @return axis maximum for the given axis or 0 if the axis is invalid
211 int libevdev_get_abs_max(const struct libevdev *dev, unsigned int code);
213 * @return axis fuzz for the given axis or 0 if the axis is invalid
215 int libevdev_get_abs_fuzz(const struct libevdev *dev, unsigned int code);
217 * @return axis flat for the given axis or 0 if the axis is invalid
219 int libevdev_get_abs_flat(const struct libevdev *dev, unsigned int code);
221 * @return axis resolution for the given axis or 0 if the axis is invalid
223 int libevdev_get_abs_resolution(const struct libevdev *dev, unsigned int code);
226 * @return The input_absinfo for the given code, or NULL if the device does
227 * not support this event code.
229 const struct input_absinfo* libevdev_get_abs_info(const struct libevdev *dev, unsigned int code);
232 * Behaviour of this function is undefined if the device does not provide
235 * @return The current value of the event.
237 * @note This function is signal-safe.
238 * @note The value for ABS_MT_ events is undefined, use
239 * libevdev_get_slot_value instead
241 * @see libevdev_get_slot_value
243 int libevdev_get_event_value(const struct libevdev *dev, unsigned int type, unsigned int code);
246 * Fetch the current value of the event type. This is a shortcut for
249 * if (libevdev_has_event_type(dev, t) && libevdev_has_event_code(dev, t, c))
250 * val = libevdev_get_event_value(dev, t, c);
253 * @return non-zero if the device supports this event code, or zero
254 * otherwise. On return of zero, value is unmodified.
256 * @note This function is signal-safe.
257 * @note The value for ABS_MT_ events is undefined, use
258 * libevdev_fetch_slot_value instead
260 * @see libevdev_fetch_slot_value
262 int libevdev_fetch_event_value(const struct libevdev *dev, unsigned int type, unsigned int code, int *value);
265 * Return the current value of the code for the given slot.
267 * The return value is undefined for a slot exceeding the available slots on
268 * the device, or for a device that does not have slots.
270 * @note This function is signal-safe.
271 * @note The value for events other than ABS_MT_ is undefined, use
272 * libevdev_fetch_value instead
274 * @see libevdev_get_value
276 int libevdev_get_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code);
279 * Fetch the current value of the code for the given slot. This is a shortcut for
282 * if (libevdev_has_event_type(dev, EV_ABS) &&
283 * libevdev_has_event_code(dev, EV_ABS, c) &&
284 * slot < device->number_of_slots)
285 * val = libevdev_get_slot_value(dev, slot, c);
288 * @return non-zero if the device supports this event code, or zero
289 * otherwise. On return of zero, value is unmodified.
291 * @note This function is signal-safe.
292 * @note The value for ABS_MT_ events is undefined, use
293 * libevdev_fetch_slot_value instead
295 * @see libevdev_fetch_slot_value
297 int libevdev_fetch_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code, int *value);
300 * Get the number of slots supported by this device.
302 * Note that the slot offset may be non-zero, use libevdev_get_abs_min() or
303 * libevdev_get_abs_info() to get the minimum slot number.
305 * @return The number of slots supported, or -1
307 int libevdev_get_num_slots(const struct libevdev *dev);
310 * Get the currently active slot. This may differ from the value
311 * an ioctl may return at this time as events may have been read off the fd
312 * since changing the slot value but those events are still in the buffer
313 * waiting to be processed. The returned value is the value a caller would
314 * see if it were to process events manually one-by-one.
316 * @return the currently active slot (logically)
318 int libevdev_get_current_slot(const struct libevdev *dev);
321 * Forcibly enable an event type on this device, even if the underlying
322 * device does not support it. While this cannot make the device actually
323 * report such events, it will now return true for libevdev_has_event_type.
325 * This is a local modification only affecting only this process and only
328 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
330 * @return 0 on success or -1 otherwise
332 * @see libevdev_has_event_type
334 int libevdev_enable_event_type(struct libevdev *dev, unsigned int type);
337 * Forcibly disable an event type on this device, even if the underlying
338 * device provides it, effectively muting all keys or axes. libevdev will
339 * filter any events matching this type and none will reach the caller.
340 * libevdev_has_event_type will return false for this type.
342 * In most cases, a caller likely only wants to disable a single code, not
343 * the whole type. Use libevdev_disable_event_code for that.
345 * This is a local modification only affecting only this process and only
348 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
350 * @return 0 on success or -1 otherwise
352 * @see libevdev_has_event_type
353 * @see libevdev_disable_event_type
355 int libevdev_disable_event_type(struct libevdev *dev, unsigned int type);
358 * Forcibly enable an event type on this device, even if the underlying
359 * device does not support it. While this cannot make the device actually
360 * report such events, it will now return true for libevdev_has_event_code.
362 * The last argument depends on the type and code:
363 * - If type is EV_ABS, the vararg must be a pointer to a struct input_absinfo
364 * containing the data for this axis.
365 * - For all other types, the argument is ignored.
367 * This function calls libevdev_enable_event_type if necessary.
369 * This is a local modification only affecting only this process and only
372 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
373 * @param code The event code to enable (ABS_X, REL_X, etc.)
374 * @param data Axis/key data, depending on type and code
376 * @return 0 on success or -1 otherwise
378 * @see libevdev_enable_event_type
380 int libevdev_enable_event_code(struct libevdev *dev, unsigned int type, unsigned int code, const void *data);
383 * Forcibly disable an event code on this device, even if the underlying
384 * device provides it, effectively muting this key or axis. libevdev will
385 * filter any events matching this type and code and none will reach the
387 * libevdev_has_event_code will return false for this code combination.
389 * Disabling all event codes for a given type will not disable the event
390 * type. Use libevdev_disable_event_type for that.
392 * This is a local modification only affecting only this process and only
395 * @param type The event type to enable (EV_ABS, EV_KEY, ...)
396 * @param code The event code to enable (ABS_X, REL_X, etc.)
398 * @return 0 on success or -1 otherwise
400 * @see libevdev_has_event_code
401 * @see libevdev_disable_event_type
403 int libevdev_disable_event_code(struct libevdev *dev, unsigned int type, unsigned int code);
406 * Set the device's EV_ABS/<code> axis to the value defined in the abs
407 * parameter. This will be written to the kernel.
409 * @return zero on success, or a negative errno on failure
411 * @see libevdev_enable_event_code
413 int libevdev_kernel_set_abs_value(struct libevdev *dev, unsigned int code, const struct input_absinfo *abs);
415 #endif /* libevdev_H */