1 /*
2  * kbdif.h -- Xen virtual keyboard/mouse
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to
6  * deal in the Software without restriction, including without limitation the
7  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
8  * sell copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  *
22  * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
23  * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
24  */
25 
26 #ifndef __XEN_PUBLIC_IO_KBDIF_H__
27 #define __XEN_PUBLIC_IO_KBDIF_H__
28 
29 /*
30  *****************************************************************************
31  *                     Feature and Parameter Negotiation
32  *****************************************************************************
33  *
34  * The two halves of a para-virtual driver utilize nodes within
35  * XenStore to communicate capabilities and to negotiate operating parameters.
36  * This section enumerates these nodes which reside in the respective front and
37  * backend portions of XenStore, following XenBus convention.
38  *
39  * All data in XenStore is stored as strings.  Nodes specifying numeric
40  * values are encoded in decimal. Integer value ranges listed below are
41  * expressed as fixed sized integer types capable of storing the conversion
42  * of a properly formated node string, without loss of information.
43  *
44  *****************************************************************************
45  *                            Backend XenBus Nodes
46  *****************************************************************************
47  *
48  *---------------------------- Features supported ----------------------------
49  *
50  * Capable backend advertises supported features by publishing
51  * corresponding entries in XenStore and puts 1 as the value of the entry.
52  * If a feature is not supported then 0 must be set or feature entry omitted.
53  *
54  * feature-abs-pointer
55  *      Values:         <uint>
56  *
57  *      Backends, which support reporting of absolute coordinates for pointer
58  *      device should set this to 1.
59  *
60  * feature-multi-touch
61  *      Values:         <uint>
62  *
63  *      Backends, which support reporting of multi-touch events
64  *      should set this to 1.
65  *
66  * feature-raw-pointer
67  *      Values:        <uint>
68  *
69  *      Backends, which support reporting raw (unscaled) absolute coordinates
70  *      for pointer devices should set this to 1. Raw (unscaled) values have
71  *      a range of [0, 0x7fff].
72  *
73  *------------------------- Pointer Device Parameters ------------------------
74  *
75  * width
76  *      Values:         <uint>
77  *
78  *      Maximum X coordinate (width) to be used by the frontend
79  *      while reporting input events, pixels, [0; UINT32_MAX].
80  *
81  * height
82  *      Values:         <uint>
83  *
84  *      Maximum Y coordinate (height) to be used by the frontend
85  *      while reporting input events, pixels, [0; UINT32_MAX].
86  *
87  *****************************************************************************
88  *                            Frontend XenBus Nodes
89  *****************************************************************************
90  *
91  *------------------------------ Feature request -----------------------------
92  *
93  * Capable frontend requests features from backend via setting corresponding
94  * entries to 1 in XenStore. Requests for features not advertised as supported
95  * by the backend have no effect.
96  *
97  * request-abs-pointer
98  *      Values:         <uint>
99  *
100  *      Request backend to report absolute pointer coordinates
101  *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
102  *
103  * request-multi-touch
104  *      Values:         <uint>
105  *
106  *      Request backend to report multi-touch events.
107  *
108  * request-raw-pointer
109  *      Values:         <uint>
110  *
111  *      Request backend to report raw unscaled absolute pointer coordinates.
112  *      This option is only valid if request-abs-pointer is also set.
113  *      Raw unscaled coordinates have the range [0, 0x7fff]
114  *
115  *----------------------- Request Transport Parameters -----------------------
116  *
117  * event-channel
118  *      Values:         <uint>
119  *
120  *      The identifier of the Xen event channel used to signal activity
121  *      in the ring buffer.
122  *
123  * page-gref
124  *      Values:         <uint>
125  *
126  *      The Xen grant reference granting permission for the backend to map
127  *      a sole page in a single page sized event ring buffer.
128  *
129  * page-ref
130  *      Values:         <uint>
131  *
132  *      OBSOLETE, not recommended for use.
133  *      PFN of the shared page.
134  *
135  *----------------------- Multi-touch Device Parameters -----------------------
136  *
137  * multi-touch-num-contacts
138  *      Values:         <uint>
139  *
140  *      Number of simultaneous touches reported.
141  *
142  * multi-touch-width
143  *      Values:         <uint>
144  *
145  *      Width of the touch area to be used by the frontend
146  *      while reporting input events, pixels, [0; UINT32_MAX].
147  *
148  * multi-touch-height
149  *      Values:         <uint>
150  *
151  *      Height of the touch area to be used by the frontend
152  *      while reporting input events, pixels, [0; UINT32_MAX].
153  */
154 
155 /*
156  * EVENT CODES.
157  */
158 
159 #define XENKBD_TYPE_MOTION             1
160 #define XENKBD_TYPE_RESERVED           2
161 #define XENKBD_TYPE_KEY                3
162 #define XENKBD_TYPE_POS                4
163 #define XENKBD_TYPE_MTOUCH             5
164 
165 /* Multi-touch event sub-codes */
166 
167 #define XENKBD_MT_EV_DOWN              0
168 #define XENKBD_MT_EV_UP                1
169 #define XENKBD_MT_EV_MOTION            2
170 #define XENKBD_MT_EV_SYN               3
171 #define XENKBD_MT_EV_SHAPE             4
172 #define XENKBD_MT_EV_ORIENT            5
173 
174 /*
175  * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
176  */
177 
178 #define XENKBD_DRIVER_NAME             "vkbd"
179 
180 #define XENKBD_FIELD_FEAT_ABS_POINTER  "feature-abs-pointer"
181 #define XENKBD_FIELD_FEAT_MTOUCH       "feature-multi-touch"
182 #define XENKBD_FIELD_REQ_ABS_POINTER   "request-abs-pointer"
183 #define XENKBD_FIELD_REQ_MTOUCH        "request-multi-touch"
184 #define XENKBD_FIELD_RING_GREF         "page-gref"
185 #define XENKBD_FIELD_EVT_CHANNEL       "event-channel"
186 #define XENKBD_FIELD_WIDTH             "width"
187 #define XENKBD_FIELD_HEIGHT            "height"
188 #define XENKBD_FIELD_MT_WIDTH          "multi-touch-width"
189 #define XENKBD_FIELD_MT_HEIGHT         "multi-touch-height"
190 #define XENKBD_FIELD_MT_NUM_CONTACTS   "multi-touch-num-contacts"
191 
192 /* OBSOLETE, not recommended for use */
193 #define XENKBD_FIELD_RING_REF          "page-ref"
194 
195 /*
196  *****************************************************************************
197  * Description of the protocol between frontend and backend driver.
198  *****************************************************************************
199  *
200  * The two halves of a Para-virtual driver communicate with
201  * each other using a shared page and an event channel.
202  * Shared page contains a ring with event structures.
203  *
204  * All reserved fields in the structures below must be 0.
205  *
206  *****************************************************************************
207  *                           Backend to frontend events
208  *****************************************************************************
209  *
210  * Frontends should ignore unknown in events.
211  * All event packets have the same length (40 octets)
212  * All event packets have common header:
213  *
214  *          0         octet
215  * +-----------------+
216  * |       type      |
217  * +-----------------+
218  * type - uint8_t, event code, XENKBD_TYPE_???
219  *
220  *
221  * Pointer relative movement event
222  *         0                1                 2               3        octet
223  * +----------------+----------------+----------------+----------------+
224  * |  _TYPE_MOTION  |                     reserved                     | 4
225  * +----------------+----------------+----------------+----------------+
226  * |                               rel_x                               | 8
227  * +----------------+----------------+----------------+----------------+
228  * |                               rel_y                               | 12
229  * +----------------+----------------+----------------+----------------+
230  * |                               rel_z                               | 16
231  * +----------------+----------------+----------------+----------------+
232  * |                             reserved                              | 20
233  * +----------------+----------------+----------------+----------------+
234  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
235  * +----------------+----------------+----------------+----------------+
236  * |                             reserved                              | 40
237  * +----------------+----------------+----------------+----------------+
238  *
239  * rel_x - int32_t, relative X motion
240  * rel_y - int32_t, relative Y motion
241  * rel_z - int32_t, relative Z motion (wheel)
242  */
243 
244 struct xenkbd_motion
245 {
246     uint8_t type;
247     int32_t rel_x;
248     int32_t rel_y;
249     int32_t rel_z;
250 };
251 
252 /*
253  * Key event (includes pointer buttons)
254  *         0                1                 2               3        octet
255  * +----------------+----------------+----------------+----------------+
256  * |  _TYPE_KEY     |     pressed    |            reserved             | 4
257  * +----------------+----------------+----------------+----------------+
258  * |                              keycode                              | 8
259  * +----------------+----------------+----------------+----------------+
260  * |                             reserved                              | 12
261  * +----------------+----------------+----------------+----------------+
262  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
263  * +----------------+----------------+----------------+----------------+
264  * |                             reserved                              | 40
265  * +----------------+----------------+----------------+----------------+
266  *
267  * pressed - uint8_t, 1 if pressed; 0 otherwise
268  * keycode - uint32_t, KEY_* from linux/input.h
269  */
270 
271 struct xenkbd_key
272 {
273     uint8_t type;
274     uint8_t pressed;
275     uint32_t keycode;
276 };
277 
278 /*
279  * Pointer absolute position event
280  *         0                1                 2               3        octet
281  * +----------------+----------------+----------------+----------------+
282  * |  _TYPE_POS     |                     reserved                     | 4
283  * +----------------+----------------+----------------+----------------+
284  * |                               abs_x                               | 8
285  * +----------------+----------------+----------------+----------------+
286  * |                               abs_y                               | 12
287  * +----------------+----------------+----------------+----------------+
288  * |                               rel_z                               | 16
289  * +----------------+----------------+----------------+----------------+
290  * |                             reserved                              | 20
291  * +----------------+----------------+----------------+----------------+
292  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
293  * +----------------+----------------+----------------+----------------+
294  * |                             reserved                              | 40
295  * +----------------+----------------+----------------+----------------+
296  *
297  * abs_x - int32_t, absolute X position (in FB pixels)
298  * abs_y - int32_t, absolute Y position (in FB pixels)
299  * rel_z - int32_t, relative Z motion (wheel)
300  */
301 
302 struct xenkbd_position
303 {
304     uint8_t type;
305     int32_t abs_x;
306     int32_t abs_y;
307     int32_t rel_z;
308 };
309 
310 /*
311  * Multi-touch event and its sub-types
312  *
313  * All multi-touch event packets have common header:
314  *
315  *         0                1                 2               3        octet
316  * +----------------+----------------+----------------+----------------+
317  * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
318  * +----------------+----------------+----------------+----------------+
319  * |                             reserved                              | 8
320  * +----------------+----------------+----------------+----------------+
321  *
322  * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
323  * contact_id - unt8_t, ID of the contact
324  *
325  * Touch interactions can consist of one or more contacts.
326  * For each contact, a series of events is generated, starting
327  * with a down event, followed by zero or more motion events,
328  * and ending with an up event. Events relating to the same
329  * contact point can be identified by the ID of the sequence: contact ID.
330  * Contact ID may be reused after XENKBD_MT_EV_UP event and
331  * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
332  *
333  * For further information please refer to documentation on Wayland [1],
334  * Linux [2] and Windows [3] multi-touch support.
335  *
336  * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
337  * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
338  * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
339  *
340  *
341  * Multi-touch down event - sent when a new touch is made: touch is assigned
342  * a unique contact ID, sent with this and consequent events related
343  * to this touch.
344  *         0                1                 2               3        octet
345  * +----------------+----------------+----------------+----------------+
346  * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
347  * +----------------+----------------+----------------+----------------+
348  * |                             reserved                              | 8
349  * +----------------+----------------+----------------+----------------+
350  * |                               abs_x                               | 12
351  * +----------------+----------------+----------------+----------------+
352  * |                               abs_y                               | 16
353  * +----------------+----------------+----------------+----------------+
354  * |                             reserved                              | 20
355  * +----------------+----------------+----------------+----------------+
356  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
357  * +----------------+----------------+----------------+----------------+
358  * |                             reserved                              | 40
359  * +----------------+----------------+----------------+----------------+
360  *
361  * abs_x - int32_t, absolute X position, in pixels
362  * abs_y - int32_t, absolute Y position, in pixels
363  *
364  * Multi-touch contact release event
365  *         0                1                 2               3        octet
366  * +----------------+----------------+----------------+----------------+
367  * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
368  * +----------------+----------------+----------------+----------------+
369  * |                             reserved                              | 8
370  * +----------------+----------------+----------------+----------------+
371  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
372  * +----------------+----------------+----------------+----------------+
373  * |                             reserved                              | 40
374  * +----------------+----------------+----------------+----------------+
375  *
376  * Multi-touch motion event
377  *         0                1                 2               3        octet
378  * +----------------+----------------+----------------+----------------+
379  * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
380  * +----------------+----------------+----------------+----------------+
381  * |                             reserved                              | 8
382  * +----------------+----------------+----------------+----------------+
383  * |                               abs_x                               | 12
384  * +----------------+----------------+----------------+----------------+
385  * |                               abs_y                               | 16
386  * +----------------+----------------+----------------+----------------+
387  * |                             reserved                              | 20
388  * +----------------+----------------+----------------+----------------+
389  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
390  * +----------------+----------------+----------------+----------------+
391  * |                             reserved                              | 40
392  * +----------------+----------------+----------------+----------------+
393  *
394  * abs_x - int32_t, absolute X position, in pixels,
395  * abs_y - int32_t, absolute Y position, in pixels,
396  *
397  * Multi-touch input synchronization event - shows end of a set of events
398  * which logically belong together.
399  *         0                1                 2               3        octet
400  * +----------------+----------------+----------------+----------------+
401  * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
402  * +----------------+----------------+----------------+----------------+
403  * |                             reserved                              | 8
404  * +----------------+----------------+----------------+----------------+
405  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
406  * +----------------+----------------+----------------+----------------+
407  * |                             reserved                              | 40
408  * +----------------+----------------+----------------+----------------+
409  *
410  * Multi-touch shape event - touch point's shape has changed its shape.
411  * Shape is approximated by an ellipse through the major and minor axis
412  * lengths: major is the longer diameter of the ellipse and minor is the
413  * shorter one. Center of the ellipse is reported via
414  * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
415  *         0                1                 2               3        octet
416  * +----------------+----------------+----------------+----------------+
417  * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
418  * +----------------+----------------+----------------+----------------+
419  * |                             reserved                              | 8
420  * +----------------+----------------+----------------+----------------+
421  * |                               major                               | 12
422  * +----------------+----------------+----------------+----------------+
423  * |                               minor                               | 16
424  * +----------------+----------------+----------------+----------------+
425  * |                             reserved                              | 20
426  * +----------------+----------------+----------------+----------------+
427  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
428  * +----------------+----------------+----------------+----------------+
429  * |                             reserved                              | 40
430  * +----------------+----------------+----------------+----------------+
431  *
432  * major - unt32_t, length of the major axis, pixels
433  * minor - unt32_t, length of the minor axis, pixels
434  *
435  * Multi-touch orientation event - touch point's shape has changed
436  * its orientation: calculated as a clockwise angle between the major axis
437  * of the ellipse and positive Y axis in degrees, [-180; +180].
438  *         0                1                 2               3        octet
439  * +----------------+----------------+----------------+----------------+
440  * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
441  * +----------------+----------------+----------------+----------------+
442  * |                             reserved                              | 8
443  * +----------------+----------------+----------------+----------------+
444  * |           orientation           |            reserved             | 12
445  * +----------------+----------------+----------------+----------------+
446  * |                             reserved                              | 16
447  * +----------------+----------------+----------------+----------------+
448  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
449  * +----------------+----------------+----------------+----------------+
450  * |                             reserved                              | 40
451  * +----------------+----------------+----------------+----------------+
452  *
453  * orientation - int16_t, clockwise angle of the major axis
454  */
455 
456 struct xenkbd_mtouch {
457     uint8_t type;            /* XENKBD_TYPE_MTOUCH */
458     uint8_t event_type;      /* XENKBD_MT_EV_??? */
459     uint8_t contact_id;
460     uint8_t reserved[5];     /* reserved for the future use */
461     union {
462         struct {
463             int32_t abs_x;   /* absolute X position, pixels */
464             int32_t abs_y;   /* absolute Y position, pixels */
465         } pos;
466         struct {
467             uint32_t major;  /* length of the major axis, pixels */
468             uint32_t minor;  /* length of the minor axis, pixels */
469         } shape;
470         int16_t orientation; /* clockwise angle of the major axis */
471     } u;
472 };
473 
474 #define XENKBD_IN_EVENT_SIZE 40
475 
476 union xenkbd_in_event
477 {
478     uint8_t type;
479     struct xenkbd_motion motion;
480     struct xenkbd_key key;
481     struct xenkbd_position pos;
482     struct xenkbd_mtouch mtouch;
483     char pad[XENKBD_IN_EVENT_SIZE];
484 };
485 
486 /*
487  *****************************************************************************
488  *                            Frontend to backend events
489  *****************************************************************************
490  *
491  * Out events may be sent only when requested by backend, and receipt
492  * of an unknown out event is an error.
493  * No out events currently defined.
494 
495  * All event packets have the same length (40 octets)
496  * All event packets have common header:
497  *          0         octet
498  * +-----------------+
499  * |       type      |
500  * +-----------------+
501  * type - uint8_t, event code
502  */
503 
504 #define XENKBD_OUT_EVENT_SIZE 40
505 
506 union xenkbd_out_event
507 {
508     uint8_t type;
509     char pad[XENKBD_OUT_EVENT_SIZE];
510 };
511 
512 /*
513  *****************************************************************************
514  *                            Shared page
515  *****************************************************************************
516  */
517 
518 #define XENKBD_IN_RING_SIZE 2048
519 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
520 #define XENKBD_IN_RING_OFFS 1024
521 #define XENKBD_IN_RING(page) \
522     ((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
523 #define XENKBD_IN_RING_REF(page, idx) \
524     (XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
525 
526 #define XENKBD_OUT_RING_SIZE 1024
527 #define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
528 #define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
529 #define XENKBD_OUT_RING(page) \
530     ((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
531 #define XENKBD_OUT_RING_REF(page, idx) \
532     (XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
533 
534 struct xenkbd_page
535 {
536     uint32_t in_cons, in_prod;
537     uint32_t out_cons, out_prod;
538 };
539 
540 #endif /* __XEN_PUBLIC_IO_KBDIF_H__ */
541 
542 /*
543  * Local variables:
544  * mode: C
545  * c-file-style: "BSD"
546  * c-basic-offset: 4
547  * tab-width: 4
548  * indent-tabs-mode: nil
549  * End:
550  */
551