xref: /openbmc/linux/include/xen/interface/io/kbdif.h (revision da1d9caf)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * kbdif.h -- Xen virtual keyboard/mouse
4  *
5  * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
6  * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
7  */
8 
9 #ifndef __XEN_PUBLIC_IO_KBDIF_H__
10 #define __XEN_PUBLIC_IO_KBDIF_H__
11 
12 /*
13  *****************************************************************************
14  *                     Feature and Parameter Negotiation
15  *****************************************************************************
16  *
17  * The two halves of a para-virtual driver utilize nodes within
18  * XenStore to communicate capabilities and to negotiate operating parameters.
19  * This section enumerates these nodes which reside in the respective front and
20  * backend portions of XenStore, following XenBus convention.
21  *
22  * All data in XenStore is stored as strings.  Nodes specifying numeric
23  * values are encoded in decimal. Integer value ranges listed below are
24  * expressed as fixed sized integer types capable of storing the conversion
25  * of a properly formated node string, without loss of information.
26  *
27  *****************************************************************************
28  *                            Backend XenBus Nodes
29  *****************************************************************************
30  *
31  *---------------------------- Features supported ----------------------------
32  *
33  * Capable backend advertises supported features by publishing
34  * corresponding entries in XenStore and puts 1 as the value of the entry.
35  * If a feature is not supported then 0 must be set or feature entry omitted.
36  *
37  * feature-disable-keyboard
38  *      Values:         <uint>
39  *
40  *      If there is no need to expose a virtual keyboard device by the
41  *      frontend then this must be set to 1.
42  *
43  * feature-disable-pointer
44  *      Values:         <uint>
45  *
46  *      If there is no need to expose a virtual pointer device by the
47  *      frontend then this must be set to 1.
48  *
49  * feature-abs-pointer
50  *      Values:         <uint>
51  *
52  *      Backends, which support reporting of absolute coordinates for pointer
53  *      device should set this to 1.
54  *
55  * feature-multi-touch
56  *      Values:         <uint>
57  *
58  *      Backends, which support reporting of multi-touch events
59  *      should set this to 1.
60  *
61  * feature-raw-pointer
62  *      Values:        <uint>
63  *
64  *      Backends, which support reporting raw (unscaled) absolute coordinates
65  *      for pointer devices should set this to 1. Raw (unscaled) values have
66  *      a range of [0, 0x7fff].
67  *
68  *-----------------------  Device Instance Parameters ------------------------
69  *
70  * unique-id
71  *      Values:         <string>
72  *
73  *      After device instance initialization it is assigned a unique ID,
74  *      so every instance of the frontend can be identified by the backend
75  *      by this ID. This can be UUID or such.
76  *
77  *------------------------- Pointer Device Parameters ------------------------
78  *
79  * width
80  *      Values:         <uint>
81  *
82  *      Maximum X coordinate (width) to be used by the frontend
83  *      while reporting input events, pixels, [0; UINT32_MAX].
84  *
85  * height
86  *      Values:         <uint>
87  *
88  *      Maximum Y coordinate (height) to be used by the frontend
89  *      while reporting input events, pixels, [0; UINT32_MAX].
90  *
91  *----------------------- Multi-touch Device Parameters ----------------------
92  *
93  * multi-touch-num-contacts
94  *      Values:         <uint>
95  *
96  *      Number of simultaneous touches reported.
97  *
98  * multi-touch-width
99  *      Values:         <uint>
100  *
101  *      Width of the touch area to be used by the frontend
102  *      while reporting input events, pixels, [0; UINT32_MAX].
103  *
104  * multi-touch-height
105  *      Values:         <uint>
106  *
107  *      Height of the touch area to be used by the frontend
108  *      while reporting input events, pixels, [0; UINT32_MAX].
109  *
110  *****************************************************************************
111  *                            Frontend XenBus Nodes
112  *****************************************************************************
113  *
114  *------------------------------ Feature request -----------------------------
115  *
116  * Capable frontend requests features from backend via setting corresponding
117  * entries to 1 in XenStore. Requests for features not advertised as supported
118  * by the backend have no effect.
119  *
120  * request-abs-pointer
121  *      Values:         <uint>
122  *
123  *      Request backend to report absolute pointer coordinates
124  *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
125  *
126  * request-multi-touch
127  *      Values:         <uint>
128  *
129  *      Request backend to report multi-touch events.
130  *
131  * request-raw-pointer
132  *      Values:         <uint>
133  *
134  *      Request backend to report raw unscaled absolute pointer coordinates.
135  *      This option is only valid if request-abs-pointer is also set.
136  *      Raw unscaled coordinates have the range [0, 0x7fff]
137  *
138  *----------------------- Request Transport Parameters -----------------------
139  *
140  * event-channel
141  *      Values:         <uint>
142  *
143  *      The identifier of the Xen event channel used to signal activity
144  *      in the ring buffer.
145  *
146  * page-gref
147  *      Values:         <uint>
148  *
149  *      The Xen grant reference granting permission for the backend to map
150  *      a sole page in a single page sized event ring buffer.
151  *
152  * page-ref
153  *      Values:         <uint>
154  *
155  *      OBSOLETE, not recommended for use.
156  *      PFN of the shared page.
157  */
158 
159 /*
160  * EVENT CODES.
161  */
162 
163 #define XENKBD_TYPE_MOTION		1
164 #define XENKBD_TYPE_RESERVED		2
165 #define XENKBD_TYPE_KEY			3
166 #define XENKBD_TYPE_POS			4
167 #define XENKBD_TYPE_MTOUCH		5
168 
169 /* Multi-touch event sub-codes */
170 
171 #define XENKBD_MT_EV_DOWN		0
172 #define XENKBD_MT_EV_UP			1
173 #define XENKBD_MT_EV_MOTION		2
174 #define XENKBD_MT_EV_SYN		3
175 #define XENKBD_MT_EV_SHAPE		4
176 #define XENKBD_MT_EV_ORIENT		5
177 
178 /*
179  * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
180  */
181 
182 #define XENKBD_DRIVER_NAME		"vkbd"
183 
184 #define XENKBD_FIELD_FEAT_DSBL_KEYBRD	"feature-disable-keyboard"
185 #define XENKBD_FIELD_FEAT_DSBL_POINTER	"feature-disable-pointer"
186 #define XENKBD_FIELD_FEAT_ABS_POINTER	"feature-abs-pointer"
187 #define XENKBD_FIELD_FEAT_RAW_POINTER	"feature-raw-pointer"
188 #define XENKBD_FIELD_FEAT_MTOUCH	"feature-multi-touch"
189 #define XENKBD_FIELD_REQ_ABS_POINTER	"request-abs-pointer"
190 #define XENKBD_FIELD_REQ_RAW_POINTER	"request-raw-pointer"
191 #define XENKBD_FIELD_REQ_MTOUCH		"request-multi-touch"
192 #define XENKBD_FIELD_RING_GREF		"page-gref"
193 #define XENKBD_FIELD_EVT_CHANNEL	"event-channel"
194 #define XENKBD_FIELD_WIDTH		"width"
195 #define XENKBD_FIELD_HEIGHT		"height"
196 #define XENKBD_FIELD_MT_WIDTH		"multi-touch-width"
197 #define XENKBD_FIELD_MT_HEIGHT		"multi-touch-height"
198 #define XENKBD_FIELD_MT_NUM_CONTACTS	"multi-touch-num-contacts"
199 #define XENKBD_FIELD_UNIQUE_ID		"unique-id"
200 
201 /* OBSOLETE, not recommended for use */
202 #define XENKBD_FIELD_RING_REF		"page-ref"
203 
204 /*
205  *****************************************************************************
206  * Description of the protocol between frontend and backend driver.
207  *****************************************************************************
208  *
209  * The two halves of a Para-virtual driver communicate with
210  * each other using a shared page and an event channel.
211  * Shared page contains a ring with event structures.
212  *
213  * All reserved fields in the structures below must be 0.
214  *
215  *****************************************************************************
216  *                           Backend to frontend events
217  *****************************************************************************
218  *
219  * Frontends should ignore unknown in events.
220  * All event packets have the same length (40 octets)
221  * All event packets have common header:
222  *
223  *          0         octet
224  * +-----------------+
225  * |       type      |
226  * +-----------------+
227  * type - uint8_t, event code, XENKBD_TYPE_???
228  *
229  *
230  * Pointer relative movement event
231  *         0                1                 2               3        octet
232  * +----------------+----------------+----------------+----------------+
233  * |  _TYPE_MOTION  |                     reserved                     | 4
234  * +----------------+----------------+----------------+----------------+
235  * |                               rel_x                               | 8
236  * +----------------+----------------+----------------+----------------+
237  * |                               rel_y                               | 12
238  * +----------------+----------------+----------------+----------------+
239  * |                               rel_z                               | 16
240  * +----------------+----------------+----------------+----------------+
241  * |                             reserved                              | 20
242  * +----------------+----------------+----------------+----------------+
243  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
244  * +----------------+----------------+----------------+----------------+
245  * |                             reserved                              | 40
246  * +----------------+----------------+----------------+----------------+
247  *
248  * rel_x - int32_t, relative X motion
249  * rel_y - int32_t, relative Y motion
250  * rel_z - int32_t, relative Z motion (wheel)
251  */
252 
253 struct xenkbd_motion {
254 	uint8_t type;
255 	int32_t rel_x;
256 	int32_t rel_y;
257 	int32_t rel_z;
258 };
259 
260 /*
261  * Key event (includes pointer buttons)
262  *         0                1                 2               3        octet
263  * +----------------+----------------+----------------+----------------+
264  * |  _TYPE_KEY     |     pressed    |            reserved             | 4
265  * +----------------+----------------+----------------+----------------+
266  * |                              keycode                              | 8
267  * +----------------+----------------+----------------+----------------+
268  * |                             reserved                              | 12
269  * +----------------+----------------+----------------+----------------+
270  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
271  * +----------------+----------------+----------------+----------------+
272  * |                             reserved                              | 40
273  * +----------------+----------------+----------------+----------------+
274  *
275  * pressed - uint8_t, 1 if pressed; 0 otherwise
276  * keycode - uint32_t, KEY_* from linux/input.h
277  */
278 
279 struct xenkbd_key {
280 	uint8_t type;
281 	uint8_t pressed;
282 	uint32_t keycode;
283 };
284 
285 /*
286  * Pointer absolute position event
287  *         0                1                 2               3        octet
288  * +----------------+----------------+----------------+----------------+
289  * |  _TYPE_POS     |                     reserved                     | 4
290  * +----------------+----------------+----------------+----------------+
291  * |                               abs_x                               | 8
292  * +----------------+----------------+----------------+----------------+
293  * |                               abs_y                               | 12
294  * +----------------+----------------+----------------+----------------+
295  * |                               rel_z                               | 16
296  * +----------------+----------------+----------------+----------------+
297  * |                             reserved                              | 20
298  * +----------------+----------------+----------------+----------------+
299  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
300  * +----------------+----------------+----------------+----------------+
301  * |                             reserved                              | 40
302  * +----------------+----------------+----------------+----------------+
303  *
304  * abs_x - int32_t, absolute X position (in FB pixels)
305  * abs_y - int32_t, absolute Y position (in FB pixels)
306  * rel_z - int32_t, relative Z motion (wheel)
307  */
308 
309 struct xenkbd_position {
310 	uint8_t type;
311 	int32_t abs_x;
312 	int32_t abs_y;
313 	int32_t rel_z;
314 };
315 
316 /*
317  * Multi-touch event and its sub-types
318  *
319  * All multi-touch event packets have common header:
320  *
321  *         0                1                 2               3        octet
322  * +----------------+----------------+----------------+----------------+
323  * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
324  * +----------------+----------------+----------------+----------------+
325  * |                             reserved                              | 8
326  * +----------------+----------------+----------------+----------------+
327  *
328  * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
329  * contact_id - unt8_t, ID of the contact
330  *
331  * Touch interactions can consist of one or more contacts.
332  * For each contact, a series of events is generated, starting
333  * with a down event, followed by zero or more motion events,
334  * and ending with an up event. Events relating to the same
335  * contact point can be identified by the ID of the sequence: contact ID.
336  * Contact ID may be reused after XENKBD_MT_EV_UP event and
337  * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
338  *
339  * For further information please refer to documentation on Wayland [1],
340  * Linux [2] and Windows [3] multi-touch support.
341  *
342  * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
343  * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.rst
344  * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
345  *
346  *
347  * Multi-touch down event - sent when a new touch is made: touch is assigned
348  * a unique contact ID, sent with this and consequent events related
349  * to this touch.
350  *         0                1                 2               3        octet
351  * +----------------+----------------+----------------+----------------+
352  * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
353  * +----------------+----------------+----------------+----------------+
354  * |                             reserved                              | 8
355  * +----------------+----------------+----------------+----------------+
356  * |                               abs_x                               | 12
357  * +----------------+----------------+----------------+----------------+
358  * |                               abs_y                               | 16
359  * +----------------+----------------+----------------+----------------+
360  * |                             reserved                              | 20
361  * +----------------+----------------+----------------+----------------+
362  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
363  * +----------------+----------------+----------------+----------------+
364  * |                             reserved                              | 40
365  * +----------------+----------------+----------------+----------------+
366  *
367  * abs_x - int32_t, absolute X position, in pixels
368  * abs_y - int32_t, absolute Y position, in pixels
369  *
370  * Multi-touch contact release event
371  *         0                1                 2               3        octet
372  * +----------------+----------------+----------------+----------------+
373  * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
374  * +----------------+----------------+----------------+----------------+
375  * |                             reserved                              | 8
376  * +----------------+----------------+----------------+----------------+
377  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
378  * +----------------+----------------+----------------+----------------+
379  * |                             reserved                              | 40
380  * +----------------+----------------+----------------+----------------+
381  *
382  * Multi-touch motion event
383  *         0                1                 2               3        octet
384  * +----------------+----------------+----------------+----------------+
385  * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
386  * +----------------+----------------+----------------+----------------+
387  * |                             reserved                              | 8
388  * +----------------+----------------+----------------+----------------+
389  * |                               abs_x                               | 12
390  * +----------------+----------------+----------------+----------------+
391  * |                               abs_y                               | 16
392  * +----------------+----------------+----------------+----------------+
393  * |                             reserved                              | 20
394  * +----------------+----------------+----------------+----------------+
395  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
396  * +----------------+----------------+----------------+----------------+
397  * |                             reserved                              | 40
398  * +----------------+----------------+----------------+----------------+
399  *
400  * abs_x - int32_t, absolute X position, in pixels,
401  * abs_y - int32_t, absolute Y position, in pixels,
402  *
403  * Multi-touch input synchronization event - shows end of a set of events
404  * which logically belong together.
405  *         0                1                 2               3        octet
406  * +----------------+----------------+----------------+----------------+
407  * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
408  * +----------------+----------------+----------------+----------------+
409  * |                             reserved                              | 8
410  * +----------------+----------------+----------------+----------------+
411  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
412  * +----------------+----------------+----------------+----------------+
413  * |                             reserved                              | 40
414  * +----------------+----------------+----------------+----------------+
415  *
416  * Multi-touch shape event - touch point's shape has changed its shape.
417  * Shape is approximated by an ellipse through the major and minor axis
418  * lengths: major is the longer diameter of the ellipse and minor is the
419  * shorter one. Center of the ellipse is reported via
420  * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
421  *         0                1                 2               3        octet
422  * +----------------+----------------+----------------+----------------+
423  * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
424  * +----------------+----------------+----------------+----------------+
425  * |                             reserved                              | 8
426  * +----------------+----------------+----------------+----------------+
427  * |                               major                               | 12
428  * +----------------+----------------+----------------+----------------+
429  * |                               minor                               | 16
430  * +----------------+----------------+----------------+----------------+
431  * |                             reserved                              | 20
432  * +----------------+----------------+----------------+----------------+
433  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
434  * +----------------+----------------+----------------+----------------+
435  * |                             reserved                              | 40
436  * +----------------+----------------+----------------+----------------+
437  *
438  * major - unt32_t, length of the major axis, pixels
439  * minor - unt32_t, length of the minor axis, pixels
440  *
441  * Multi-touch orientation event - touch point's shape has changed
442  * its orientation: calculated as a clockwise angle between the major axis
443  * of the ellipse and positive Y axis in degrees, [-180; +180].
444  *         0                1                 2               3        octet
445  * +----------------+----------------+----------------+----------------+
446  * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
447  * +----------------+----------------+----------------+----------------+
448  * |                             reserved                              | 8
449  * +----------------+----------------+----------------+----------------+
450  * |           orientation           |            reserved             | 12
451  * +----------------+----------------+----------------+----------------+
452  * |                             reserved                              | 16
453  * +----------------+----------------+----------------+----------------+
454  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
455  * +----------------+----------------+----------------+----------------+
456  * |                             reserved                              | 40
457  * +----------------+----------------+----------------+----------------+
458  *
459  * orientation - int16_t, clockwise angle of the major axis
460  */
461 
462 struct xenkbd_mtouch {
463 	uint8_t type;			/* XENKBD_TYPE_MTOUCH */
464 	uint8_t event_type;		/* XENKBD_MT_EV_??? */
465 	uint8_t contact_id;
466 	uint8_t reserved[5];		/* reserved for the future use */
467 	union {
468 		struct {
469 			int32_t abs_x;	/* absolute X position, pixels */
470 			int32_t abs_y;	/* absolute Y position, pixels */
471 		} pos;
472 		struct {
473 			uint32_t major;	/* length of the major axis, pixels */
474 			uint32_t minor;	/* length of the minor axis, pixels */
475 		} shape;
476 		int16_t orientation;	/* clockwise angle of the major axis */
477 	} u;
478 };
479 
480 #define XENKBD_IN_EVENT_SIZE 40
481 
482 union xenkbd_in_event {
483 	uint8_t type;
484 	struct xenkbd_motion motion;
485 	struct xenkbd_key key;
486 	struct xenkbd_position pos;
487 	struct xenkbd_mtouch mtouch;
488 	char pad[XENKBD_IN_EVENT_SIZE];
489 };
490 
491 /*
492  *****************************************************************************
493  *                            Frontend to backend events
494  *****************************************************************************
495  *
496  * Out events may be sent only when requested by backend, and receipt
497  * of an unknown out event is an error.
498  * No out events currently defined.
499 
500  * All event packets have the same length (40 octets)
501  * All event packets have common header:
502  *          0         octet
503  * +-----------------+
504  * |       type      |
505  * +-----------------+
506  * type - uint8_t, event code
507  */
508 
509 #define XENKBD_OUT_EVENT_SIZE 40
510 
511 union xenkbd_out_event {
512 	uint8_t type;
513 	char pad[XENKBD_OUT_EVENT_SIZE];
514 };
515 
516 /*
517  *****************************************************************************
518  *                            Shared page
519  *****************************************************************************
520  */
521 
522 #define XENKBD_IN_RING_SIZE 2048
523 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
524 #define XENKBD_IN_RING_OFFS 1024
525 #define XENKBD_IN_RING(page) \
526 	((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
527 #define XENKBD_IN_RING_REF(page, idx) \
528 	(XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
529 
530 #define XENKBD_OUT_RING_SIZE 1024
531 #define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
532 #define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
533 #define XENKBD_OUT_RING(page) \
534 	((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
535 #define XENKBD_OUT_RING_REF(page, idx) \
536 	(XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
537 
538 struct xenkbd_page {
539 	uint32_t in_cons, in_prod;
540 	uint32_t out_cons, out_prod;
541 };
542 
543 #endif /* __XEN_PUBLIC_IO_KBDIF_H__ */
544