xref: /openbmc/linux/include/xen/interface/io/kbdif.h (revision faa16bc4)
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  *------------------------- Pointer Device Parameters ------------------------
67  *
68  * width
69  *      Values:         <uint>
70  *
71  *      Maximum X coordinate (width) to be used by the frontend
72  *      while reporting input events, pixels, [0; UINT32_MAX].
73  *
74  * height
75  *      Values:         <uint>
76  *
77  *      Maximum Y coordinate (height) to be used by the frontend
78  *      while reporting input events, pixels, [0; UINT32_MAX].
79  *
80  *****************************************************************************
81  *                            Frontend XenBus Nodes
82  *****************************************************************************
83  *
84  *------------------------------ Feature request -----------------------------
85  *
86  * Capable frontend requests features from backend via setting corresponding
87  * entries to 1 in XenStore. Requests for features not advertised as supported
88  * by the backend have no effect.
89  *
90  * request-abs-pointer
91  *      Values:         <uint>
92  *
93  *      Request backend to report absolute pointer coordinates
94  *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
95  *
96  * request-multi-touch
97  *      Values:         <uint>
98  *
99  *      Request backend to report multi-touch events.
100  *
101  *----------------------- Request Transport Parameters -----------------------
102  *
103  * event-channel
104  *      Values:         <uint>
105  *
106  *      The identifier of the Xen event channel used to signal activity
107  *      in the ring buffer.
108  *
109  * page-gref
110  *      Values:         <uint>
111  *
112  *      The Xen grant reference granting permission for the backend to map
113  *      a sole page in a single page sized event ring buffer.
114  *
115  * page-ref
116  *      Values:         <uint>
117  *
118  *      OBSOLETE, not recommended for use.
119  *      PFN of the shared page.
120  *
121  *----------------------- Multi-touch Device Parameters -----------------------
122  *
123  * multi-touch-num-contacts
124  *      Values:         <uint>
125  *
126  *      Number of simultaneous touches reported.
127  *
128  * multi-touch-width
129  *      Values:         <uint>
130  *
131  *      Width of the touch area to be used by the frontend
132  *      while reporting input events, pixels, [0; UINT32_MAX].
133  *
134  * multi-touch-height
135  *      Values:         <uint>
136  *
137  *      Height of the touch area to be used by the frontend
138  *      while reporting input events, pixels, [0; UINT32_MAX].
139  */
140 
141 /*
142  * EVENT CODES.
143  */
144 
145 #define XENKBD_TYPE_MOTION		1
146 #define XENKBD_TYPE_RESERVED		2
147 #define XENKBD_TYPE_KEY			3
148 #define XENKBD_TYPE_POS			4
149 #define XENKBD_TYPE_MTOUCH		5
150 
151 /* Multi-touch event sub-codes */
152 
153 #define XENKBD_MT_EV_DOWN		0
154 #define XENKBD_MT_EV_UP			1
155 #define XENKBD_MT_EV_MOTION		2
156 #define XENKBD_MT_EV_SYN		3
157 #define XENKBD_MT_EV_SHAPE		4
158 #define XENKBD_MT_EV_ORIENT		5
159 
160 /*
161  * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
162  */
163 
164 #define XENKBD_DRIVER_NAME		"vkbd"
165 
166 #define XENKBD_FIELD_FEAT_ABS_POINTER	"feature-abs-pointer"
167 #define XENKBD_FIELD_FEAT_MTOUCH	"feature-multi-touch"
168 #define XENKBD_FIELD_REQ_ABS_POINTER	"request-abs-pointer"
169 #define XENKBD_FIELD_REQ_MTOUCH		"request-multi-touch"
170 #define XENKBD_FIELD_RING_GREF		"page-gref"
171 #define XENKBD_FIELD_EVT_CHANNEL	"event-channel"
172 #define XENKBD_FIELD_WIDTH		"width"
173 #define XENKBD_FIELD_HEIGHT		"height"
174 #define XENKBD_FIELD_MT_WIDTH		"multi-touch-width"
175 #define XENKBD_FIELD_MT_HEIGHT		"multi-touch-height"
176 #define XENKBD_FIELD_MT_NUM_CONTACTS	"multi-touch-num-contacts"
177 
178 /* OBSOLETE, not recommended for use */
179 #define XENKBD_FIELD_RING_REF		"page-ref"
180 
181 /*
182  *****************************************************************************
183  * Description of the protocol between frontend and backend driver.
184  *****************************************************************************
185  *
186  * The two halves of a Para-virtual driver communicate with
187  * each other using a shared page and an event channel.
188  * Shared page contains a ring with event structures.
189  *
190  * All reserved fields in the structures below must be 0.
191  *
192  *****************************************************************************
193  *                           Backend to frontend events
194  *****************************************************************************
195  *
196  * Frontends should ignore unknown in events.
197  * All event packets have the same length (40 octets)
198  * All event packets have common header:
199  *
200  *          0         octet
201  * +-----------------+
202  * |       type      |
203  * +-----------------+
204  * type - uint8_t, event code, XENKBD_TYPE_???
205  *
206  *
207  * Pointer relative movement event
208  *         0                1                 2               3        octet
209  * +----------------+----------------+----------------+----------------+
210  * |  _TYPE_MOTION  |                     reserved                     | 4
211  * +----------------+----------------+----------------+----------------+
212  * |                               rel_x                               | 8
213  * +----------------+----------------+----------------+----------------+
214  * |                               rel_y                               | 12
215  * +----------------+----------------+----------------+----------------+
216  * |                               rel_z                               | 16
217  * +----------------+----------------+----------------+----------------+
218  * |                             reserved                              | 20
219  * +----------------+----------------+----------------+----------------+
220  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
221  * +----------------+----------------+----------------+----------------+
222  * |                             reserved                              | 40
223  * +----------------+----------------+----------------+----------------+
224  *
225  * rel_x - int32_t, relative X motion
226  * rel_y - int32_t, relative Y motion
227  * rel_z - int32_t, relative Z motion (wheel)
228  */
229 
230 struct xenkbd_motion {
231 	uint8_t type;
232 	int32_t rel_x;
233 	int32_t rel_y;
234 	int32_t rel_z;
235 };
236 
237 /*
238  * Key event (includes pointer buttons)
239  *         0                1                 2               3        octet
240  * +----------------+----------------+----------------+----------------+
241  * |  _TYPE_KEY     |     pressed    |            reserved             | 4
242  * +----------------+----------------+----------------+----------------+
243  * |                              keycode                              | 8
244  * +----------------+----------------+----------------+----------------+
245  * |                             reserved                              | 12
246  * +----------------+----------------+----------------+----------------+
247  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
248  * +----------------+----------------+----------------+----------------+
249  * |                             reserved                              | 40
250  * +----------------+----------------+----------------+----------------+
251  *
252  * pressed - uint8_t, 1 if pressed; 0 otherwise
253  * keycode - uint32_t, KEY_* from linux/input.h
254  */
255 
256 struct xenkbd_key {
257 	uint8_t type;
258 	uint8_t pressed;
259 	uint32_t keycode;
260 };
261 
262 /*
263  * Pointer absolute position event
264  *         0                1                 2               3        octet
265  * +----------------+----------------+----------------+----------------+
266  * |  _TYPE_POS     |                     reserved                     | 4
267  * +----------------+----------------+----------------+----------------+
268  * |                               abs_x                               | 8
269  * +----------------+----------------+----------------+----------------+
270  * |                               abs_y                               | 12
271  * +----------------+----------------+----------------+----------------+
272  * |                               rel_z                               | 16
273  * +----------------+----------------+----------------+----------------+
274  * |                             reserved                              | 20
275  * +----------------+----------------+----------------+----------------+
276  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
277  * +----------------+----------------+----------------+----------------+
278  * |                             reserved                              | 40
279  * +----------------+----------------+----------------+----------------+
280  *
281  * abs_x - int32_t, absolute X position (in FB pixels)
282  * abs_y - int32_t, absolute Y position (in FB pixels)
283  * rel_z - int32_t, relative Z motion (wheel)
284  */
285 
286 struct xenkbd_position {
287 	uint8_t type;
288 	int32_t abs_x;
289 	int32_t abs_y;
290 	int32_t rel_z;
291 };
292 
293 /*
294  * Multi-touch event and its sub-types
295  *
296  * All multi-touch event packets have common header:
297  *
298  *         0                1                 2               3        octet
299  * +----------------+----------------+----------------+----------------+
300  * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
301  * +----------------+----------------+----------------+----------------+
302  * |                             reserved                              | 8
303  * +----------------+----------------+----------------+----------------+
304  *
305  * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
306  * contact_id - unt8_t, ID of the contact
307  *
308  * Touch interactions can consist of one or more contacts.
309  * For each contact, a series of events is generated, starting
310  * with a down event, followed by zero or more motion events,
311  * and ending with an up event. Events relating to the same
312  * contact point can be identified by the ID of the sequence: contact ID.
313  * Contact ID may be reused after XENKBD_MT_EV_UP event and
314  * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
315  *
316  * For further information please refer to documentation on Wayland [1],
317  * Linux [2] and Windows [3] multi-touch support.
318  *
319  * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
320  * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.rst
321  * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
322  *
323  *
324  * Multi-touch down event - sent when a new touch is made: touch is assigned
325  * a unique contact ID, sent with this and consequent events related
326  * to this touch.
327  *         0                1                 2               3        octet
328  * +----------------+----------------+----------------+----------------+
329  * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
330  * +----------------+----------------+----------------+----------------+
331  * |                             reserved                              | 8
332  * +----------------+----------------+----------------+----------------+
333  * |                               abs_x                               | 12
334  * +----------------+----------------+----------------+----------------+
335  * |                               abs_y                               | 16
336  * +----------------+----------------+----------------+----------------+
337  * |                             reserved                              | 20
338  * +----------------+----------------+----------------+----------------+
339  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
340  * +----------------+----------------+----------------+----------------+
341  * |                             reserved                              | 40
342  * +----------------+----------------+----------------+----------------+
343  *
344  * abs_x - int32_t, absolute X position, in pixels
345  * abs_y - int32_t, absolute Y position, in pixels
346  *
347  * Multi-touch contact release event
348  *         0                1                 2               3        octet
349  * +----------------+----------------+----------------+----------------+
350  * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
351  * +----------------+----------------+----------------+----------------+
352  * |                             reserved                              | 8
353  * +----------------+----------------+----------------+----------------+
354  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
355  * +----------------+----------------+----------------+----------------+
356  * |                             reserved                              | 40
357  * +----------------+----------------+----------------+----------------+
358  *
359  * Multi-touch motion event
360  *         0                1                 2               3        octet
361  * +----------------+----------------+----------------+----------------+
362  * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
363  * +----------------+----------------+----------------+----------------+
364  * |                             reserved                              | 8
365  * +----------------+----------------+----------------+----------------+
366  * |                               abs_x                               | 12
367  * +----------------+----------------+----------------+----------------+
368  * |                               abs_y                               | 16
369  * +----------------+----------------+----------------+----------------+
370  * |                             reserved                              | 20
371  * +----------------+----------------+----------------+----------------+
372  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
373  * +----------------+----------------+----------------+----------------+
374  * |                             reserved                              | 40
375  * +----------------+----------------+----------------+----------------+
376  *
377  * abs_x - int32_t, absolute X position, in pixels,
378  * abs_y - int32_t, absolute Y position, in pixels,
379  *
380  * Multi-touch input synchronization event - shows end of a set of events
381  * which logically belong together.
382  *         0                1                 2               3        octet
383  * +----------------+----------------+----------------+----------------+
384  * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
385  * +----------------+----------------+----------------+----------------+
386  * |                             reserved                              | 8
387  * +----------------+----------------+----------------+----------------+
388  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
389  * +----------------+----------------+----------------+----------------+
390  * |                             reserved                              | 40
391  * +----------------+----------------+----------------+----------------+
392  *
393  * Multi-touch shape event - touch point's shape has changed its shape.
394  * Shape is approximated by an ellipse through the major and minor axis
395  * lengths: major is the longer diameter of the ellipse and minor is the
396  * shorter one. Center of the ellipse is reported via
397  * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
398  *         0                1                 2               3        octet
399  * +----------------+----------------+----------------+----------------+
400  * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
401  * +----------------+----------------+----------------+----------------+
402  * |                             reserved                              | 8
403  * +----------------+----------------+----------------+----------------+
404  * |                               major                               | 12
405  * +----------------+----------------+----------------+----------------+
406  * |                               minor                               | 16
407  * +----------------+----------------+----------------+----------------+
408  * |                             reserved                              | 20
409  * +----------------+----------------+----------------+----------------+
410  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
411  * +----------------+----------------+----------------+----------------+
412  * |                             reserved                              | 40
413  * +----------------+----------------+----------------+----------------+
414  *
415  * major - unt32_t, length of the major axis, pixels
416  * minor - unt32_t, length of the minor axis, pixels
417  *
418  * Multi-touch orientation event - touch point's shape has changed
419  * its orientation: calculated as a clockwise angle between the major axis
420  * of the ellipse and positive Y axis in degrees, [-180; +180].
421  *         0                1                 2               3        octet
422  * +----------------+----------------+----------------+----------------+
423  * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
424  * +----------------+----------------+----------------+----------------+
425  * |                             reserved                              | 8
426  * +----------------+----------------+----------------+----------------+
427  * |           orientation           |            reserved             | 12
428  * +----------------+----------------+----------------+----------------+
429  * |                             reserved                              | 16
430  * +----------------+----------------+----------------+----------------+
431  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
432  * +----------------+----------------+----------------+----------------+
433  * |                             reserved                              | 40
434  * +----------------+----------------+----------------+----------------+
435  *
436  * orientation - int16_t, clockwise angle of the major axis
437  */
438 
439 struct xenkbd_mtouch {
440 	uint8_t type;			/* XENKBD_TYPE_MTOUCH */
441 	uint8_t event_type;		/* XENKBD_MT_EV_??? */
442 	uint8_t contact_id;
443 	uint8_t reserved[5];		/* reserved for the future use */
444 	union {
445 		struct {
446 			int32_t abs_x;	/* absolute X position, pixels */
447 			int32_t abs_y;	/* absolute Y position, pixels */
448 		} pos;
449 		struct {
450 			uint32_t major;	/* length of the major axis, pixels */
451 			uint32_t minor;	/* length of the minor axis, pixels */
452 		} shape;
453 		int16_t orientation;	/* clockwise angle of the major axis */
454 	} u;
455 };
456 
457 #define XENKBD_IN_EVENT_SIZE 40
458 
459 union xenkbd_in_event {
460 	uint8_t type;
461 	struct xenkbd_motion motion;
462 	struct xenkbd_key key;
463 	struct xenkbd_position pos;
464 	struct xenkbd_mtouch mtouch;
465 	char pad[XENKBD_IN_EVENT_SIZE];
466 };
467 
468 /*
469  *****************************************************************************
470  *                            Frontend to backend events
471  *****************************************************************************
472  *
473  * Out events may be sent only when requested by backend, and receipt
474  * of an unknown out event is an error.
475  * No out events currently defined.
476 
477  * All event packets have the same length (40 octets)
478  * All event packets have common header:
479  *          0         octet
480  * +-----------------+
481  * |       type      |
482  * +-----------------+
483  * type - uint8_t, event code
484  */
485 
486 #define XENKBD_OUT_EVENT_SIZE 40
487 
488 union xenkbd_out_event {
489 	uint8_t type;
490 	char pad[XENKBD_OUT_EVENT_SIZE];
491 };
492 
493 /*
494  *****************************************************************************
495  *                            Shared page
496  *****************************************************************************
497  */
498 
499 #define XENKBD_IN_RING_SIZE 2048
500 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
501 #define XENKBD_IN_RING_OFFS 1024
502 #define XENKBD_IN_RING(page) \
503 	((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
504 #define XENKBD_IN_RING_REF(page, idx) \
505 	(XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
506 
507 #define XENKBD_OUT_RING_SIZE 1024
508 #define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
509 #define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
510 #define XENKBD_OUT_RING(page) \
511 	((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
512 #define XENKBD_OUT_RING_REF(page, idx) \
513 	(XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
514 
515 struct xenkbd_page {
516 	uint32_t in_cons, in_prod;
517 	uint32_t out_cons, out_prod;
518 };
519 
520 #endif /* __XEN_PUBLIC_IO_KBDIF_H__ */
521