include/xen/interface/io/kbdif.h

   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-disable-keyboard
  55  *      Values:         <uint>
  56  *
  57  *      If there is no need to expose a virtual keyboard device by the
  58  *      frontend then this must be set to 1.
  59  *
  60  * feature-disable-pointer
  61  *      Values:         <uint>
  62  *
  63  *      If there is no need to expose a virtual pointer device by the
  64  *      frontend then this must be set to 1.
  65  *
  66  * feature-abs-pointer
  67  *      Values:         <uint>
  68  *
  69  *      Backends, which support reporting of absolute coordinates for pointer
  70  *      device should set this to 1.
  71  *
  72  * feature-multi-touch
  73  *      Values:         <uint>
  74  *
  75  *      Backends, which support reporting of multi-touch events
  76  *      should set this to 1.
  77  *
  78  * feature-raw-pointer
  79  *      Values:        <uint>
  80  *
  81  *      Backends, which support reporting raw (unscaled) absolute coordinates
  82  *      for pointer devices should set this to 1. Raw (unscaled) values have
  83  *      a range of [0, 0x7fff].
  84  *
  85  *-----------------------  Device Instance Parameters ------------------------
  86  *
  87  * unique-id
  88  *      Values:         <string>
  89  *
  90  *      After device instance initialization it is assigned a unique ID,
  91  *      so every instance of the frontend can be identified by the backend
  92  *      by this ID. This can be UUID or such.
  93  *
  94  *------------------------- Pointer Device Parameters ------------------------
  95  *
  96  * width
  97  *      Values:         <uint>
  98  *
  99  *      Maximum X coordinate (width) to be used by the frontend
 100  *      while reporting input events, pixels, [0; UINT32_MAX].
 101  *
 102  * height
 103  *      Values:         <uint>
 104  *
 105  *      Maximum Y coordinate (height) to be used by the frontend
 106  *      while reporting input events, pixels, [0; UINT32_MAX].
 107  *
 108  *----------------------- Multi-touch Device Parameters ----------------------
 109  *
 110  * multi-touch-num-contacts
 111  *      Values:         <uint>
 112  *
 113  *      Number of simultaneous touches reported.
 114  *
 115  * multi-touch-width
 116  *      Values:         <uint>
 117  *
 118  *      Width of the touch area to be used by the frontend
 119  *      while reporting input events, pixels, [0; UINT32_MAX].
 120  *
 121  * multi-touch-height
 122  *      Values:         <uint>
 123  *
 124  *      Height of the touch area to be used by the frontend
 125  *      while reporting input events, pixels, [0; UINT32_MAX].
 126  *
 127  *****************************************************************************
 128  *                            Frontend XenBus Nodes
 129  *****************************************************************************
 130  *
 131  *------------------------------ Feature request -----------------------------
 132  *
 133  * Capable frontend requests features from backend via setting corresponding
 134  * entries to 1 in XenStore. Requests for features not advertised as supported
 135  * by the backend have no effect.
 136  *
 137  * request-abs-pointer
 138  *      Values:         <uint>
 139  *
 140  *      Request backend to report absolute pointer coordinates
 141  *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
 142  *
 143  * request-multi-touch
 144  *      Values:         <uint>
 145  *
 146  *      Request backend to report multi-touch events.
 147  *
 148  * request-raw-pointer
 149  *      Values:         <uint>
 150  *
 151  *      Request backend to report raw unscaled absolute pointer coordinates.
 152  *      This option is only valid if request-abs-pointer is also set.
 153  *      Raw unscaled coordinates have the range [0, 0x7fff]
 154  *
 155  *----------------------- Request Transport Parameters -----------------------
 156  *
 157  * event-channel
 158  *      Values:         <uint>
 159  *
 160  *      The identifier of the Xen event channel used to signal activity
 161  *      in the ring buffer.
 162  *
 163  * page-gref
 164  *      Values:         <uint>
 165  *
 166  *      The Xen grant reference granting permission for the backend to map
 167  *      a sole page in a single page sized event ring buffer.
 168  *
 169  * page-ref
 170  *      Values:         <uint>
 171  *
 172  *      OBSOLETE, not recommended for use.
 173  *      PFN of the shared page.
 174  */
 175
 176 /*
 177  * EVENT CODES.
 178  */
 179
 180 #define XENKBD_TYPE_MOTION              1
 181 #define XENKBD_TYPE_RESERVED            2
 182 #define XENKBD_TYPE_KEY                 3
 183 #define XENKBD_TYPE_POS                 4
 184 #define XENKBD_TYPE_MTOUCH              5
 185
 186 /* Multi-touch event sub-codes */
 187
 188 #define XENKBD_MT_EV_DOWN               0
 189 #define XENKBD_MT_EV_UP                 1
 190 #define XENKBD_MT_EV_MOTION             2
 191 #define XENKBD_MT_EV_SYN                3
 192 #define XENKBD_MT_EV_SHAPE              4
 193 #define XENKBD_MT_EV_ORIENT             5
 194
 195 /*
 196  * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
 197  */
 198
 199 #define XENKBD_DRIVER_NAME              "vkbd"
 200
 201 #define XENKBD_FIELD_FEAT_DSBL_KEYBRD   "feature-disable-keyboard"
 202 #define XENKBD_FIELD_FEAT_DSBL_POINTER  "feature-disable-pointer"
 203 #define XENKBD_FIELD_FEAT_ABS_POINTER   "feature-abs-pointer"
 204 #define XENKBD_FIELD_FEAT_RAW_POINTER   "feature-raw-pointer"
 205 #define XENKBD_FIELD_FEAT_MTOUCH        "feature-multi-touch"
 206 #define XENKBD_FIELD_REQ_ABS_POINTER    "request-abs-pointer"
 207 #define XENKBD_FIELD_REQ_RAW_POINTER    "request-raw-pointer"
 208 #define XENKBD_FIELD_REQ_MTOUCH         "request-multi-touch"
 209 #define XENKBD_FIELD_RING_GREF          "page-gref"
 210 #define XENKBD_FIELD_EVT_CHANNEL        "event-channel"
 211 #define XENKBD_FIELD_WIDTH              "width"
 212 #define XENKBD_FIELD_HEIGHT             "height"
 213 #define XENKBD_FIELD_MT_WIDTH           "multi-touch-width"
 214 #define XENKBD_FIELD_MT_HEIGHT          "multi-touch-height"
 215 #define XENKBD_FIELD_MT_NUM_CONTACTS    "multi-touch-num-contacts"
 216 #define XENKBD_FIELD_UNIQUE_ID          "unique-id"
 217
 218 /* OBSOLETE, not recommended for use */
 219 #define XENKBD_FIELD_RING_REF           "page-ref"
 220
 221 /*
 222  *****************************************************************************
 223  * Description of the protocol between frontend and backend driver.
 224  *****************************************************************************
 225  *
 226  * The two halves of a Para-virtual driver communicate with
 227  * each other using a shared page and an event channel.
 228  * Shared page contains a ring with event structures.
 229  *
 230  * All reserved fields in the structures below must be 0.
 231  *
 232  *****************************************************************************
 233  *                           Backend to frontend events
 234  *****************************************************************************
 235  *
 236  * Frontends should ignore unknown in events.
 237  * All event packets have the same length (40 octets)
 238  * All event packets have common header:
 239  *
 240  *          0         octet
 241  * +-----------------+
 242  * |       type      |
 243  * +-----------------+
 244  * type - uint8_t, event code, XENKBD_TYPE_???
 245  *
 246  *
 247  * Pointer relative movement event
 248  *         0                1                 2               3        octet
 249  * +----------------+----------------+----------------+----------------+
 250  * |  _TYPE_MOTION  |                     reserved                     | 4
 251  * +----------------+----------------+----------------+----------------+
 252  * |                               rel_x                               | 8
 253  * +----------------+----------------+----------------+----------------+
 254  * |                               rel_y                               | 12
 255  * +----------------+----------------+----------------+----------------+
 256  * |                               rel_z                               | 16
 257  * +----------------+----------------+----------------+----------------+
 258  * |                             reserved                              | 20
 259  * +----------------+----------------+----------------+----------------+
 260  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 261  * +----------------+----------------+----------------+----------------+
 262  * |                             reserved                              | 40
 263  * +----------------+----------------+----------------+----------------+
 264  *
 265  * rel_x - int32_t, relative X motion
 266  * rel_y - int32_t, relative Y motion
 267  * rel_z - int32_t, relative Z motion (wheel)
 268  */
 269
 270 struct xenkbd_motion {
 271         uint8_t type;
 272         int32_t rel_x;
 273         int32_t rel_y;
 274         int32_t rel_z;
 275 };
 276
 277 /*
 278  * Key event (includes pointer buttons)
 279  *         0                1                 2               3        octet
 280  * +----------------+----------------+----------------+----------------+
 281  * |  _TYPE_KEY     |     pressed    |            reserved             | 4
 282  * +----------------+----------------+----------------+----------------+
 283  * |                              keycode                              | 8
 284  * +----------------+----------------+----------------+----------------+
 285  * |                             reserved                              | 12
 286  * +----------------+----------------+----------------+----------------+
 287  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 288  * +----------------+----------------+----------------+----------------+
 289  * |                             reserved                              | 40
 290  * +----------------+----------------+----------------+----------------+
 291  *
 292  * pressed - uint8_t, 1 if pressed; 0 otherwise
 293  * keycode - uint32_t, KEY_* from linux/input.h
 294  */
 295
 296 struct xenkbd_key {
 297         uint8_t type;
 298         uint8_t pressed;
 299         uint32_t keycode;
 300 };
 301
 302 /*
 303  * Pointer absolute position event
 304  *         0                1                 2               3        octet
 305  * +----------------+----------------+----------------+----------------+
 306  * |  _TYPE_POS     |                     reserved                     | 4
 307  * +----------------+----------------+----------------+----------------+
 308  * |                               abs_x                               | 8
 309  * +----------------+----------------+----------------+----------------+
 310  * |                               abs_y                               | 12
 311  * +----------------+----------------+----------------+----------------+
 312  * |                               rel_z                               | 16
 313  * +----------------+----------------+----------------+----------------+
 314  * |                             reserved                              | 20
 315  * +----------------+----------------+----------------+----------------+
 316  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 317  * +----------------+----------------+----------------+----------------+
 318  * |                             reserved                              | 40
 319  * +----------------+----------------+----------------+----------------+
 320  *
 321  * abs_x - int32_t, absolute X position (in FB pixels)
 322  * abs_y - int32_t, absolute Y position (in FB pixels)
 323  * rel_z - int32_t, relative Z motion (wheel)
 324  */
 325
 326 struct xenkbd_position {
 327         uint8_t type;
 328         int32_t abs_x;
 329         int32_t abs_y;
 330         int32_t rel_z;
 331 };
 332
 333 /*
 334  * Multi-touch event and its sub-types
 335  *
 336  * All multi-touch event packets have common header:
 337  *
 338  *         0                1                 2               3        octet
 339  * +----------------+----------------+----------------+----------------+
 340  * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
 341  * +----------------+----------------+----------------+----------------+
 342  * |                             reserved                              | 8
 343  * +----------------+----------------+----------------+----------------+
 344  *
 345  * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
 346  * contact_id - unt8_t, ID of the contact
 347  *
 348  * Touch interactions can consist of one or more contacts.
 349  * For each contact, a series of events is generated, starting
 350  * with a down event, followed by zero or more motion events,
 351  * and ending with an up event. Events relating to the same
 352  * contact point can be identified by the ID of the sequence: contact ID.
 353  * Contact ID may be reused after XENKBD_MT_EV_UP event and
 354  * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
 355  *
 356  * For further information please refer to documentation on Wayland [1],
 357  * Linux [2] and Windows [3] multi-touch support.
 358  *
 359  * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
 360  * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.rst
 361  * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
 362  *
 363  *
 364  * Multi-touch down event - sent when a new touch is made: touch is assigned
 365  * a unique contact ID, sent with this and consequent events related
 366  * to this touch.
 367  *         0                1                 2               3        octet
 368  * +----------------+----------------+----------------+----------------+
 369  * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
 370  * +----------------+----------------+----------------+----------------+
 371  * |                             reserved                              | 8
 372  * +----------------+----------------+----------------+----------------+
 373  * |                               abs_x                               | 12
 374  * +----------------+----------------+----------------+----------------+
 375  * |                               abs_y                               | 16
 376  * +----------------+----------------+----------------+----------------+
 377  * |                             reserved                              | 20
 378  * +----------------+----------------+----------------+----------------+
 379  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 380  * +----------------+----------------+----------------+----------------+
 381  * |                             reserved                              | 40
 382  * +----------------+----------------+----------------+----------------+
 383  *
 384  * abs_x - int32_t, absolute X position, in pixels
 385  * abs_y - int32_t, absolute Y position, in pixels
 386  *
 387  * Multi-touch contact release event
 388  *         0                1                 2               3        octet
 389  * +----------------+----------------+----------------+----------------+
 390  * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
 391  * +----------------+----------------+----------------+----------------+
 392  * |                             reserved                              | 8
 393  * +----------------+----------------+----------------+----------------+
 394  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 395  * +----------------+----------------+----------------+----------------+
 396  * |                             reserved                              | 40
 397  * +----------------+----------------+----------------+----------------+
 398  *
 399  * Multi-touch motion event
 400  *         0                1                 2               3        octet
 401  * +----------------+----------------+----------------+----------------+
 402  * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
 403  * +----------------+----------------+----------------+----------------+
 404  * |                             reserved                              | 8
 405  * +----------------+----------------+----------------+----------------+
 406  * |                               abs_x                               | 12
 407  * +----------------+----------------+----------------+----------------+
 408  * |                               abs_y                               | 16
 409  * +----------------+----------------+----------------+----------------+
 410  * |                             reserved                              | 20
 411  * +----------------+----------------+----------------+----------------+
 412  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 413  * +----------------+----------------+----------------+----------------+
 414  * |                             reserved                              | 40
 415  * +----------------+----------------+----------------+----------------+
 416  *
 417  * abs_x - int32_t, absolute X position, in pixels,
 418  * abs_y - int32_t, absolute Y position, in pixels,
 419  *
 420  * Multi-touch input synchronization event - shows end of a set of events
 421  * which logically belong together.
 422  *         0                1                 2               3        octet
 423  * +----------------+----------------+----------------+----------------+
 424  * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
 425  * +----------------+----------------+----------------+----------------+
 426  * |                             reserved                              | 8
 427  * +----------------+----------------+----------------+----------------+
 428  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 429  * +----------------+----------------+----------------+----------------+
 430  * |                             reserved                              | 40
 431  * +----------------+----------------+----------------+----------------+
 432  *
 433  * Multi-touch shape event - touch point's shape has changed its shape.
 434  * Shape is approximated by an ellipse through the major and minor axis
 435  * lengths: major is the longer diameter of the ellipse and minor is the
 436  * shorter one. Center of the ellipse is reported via
 437  * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
 438  *         0                1                 2               3        octet
 439  * +----------------+----------------+----------------+----------------+
 440  * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
 441  * +----------------+----------------+----------------+----------------+
 442  * |                             reserved                              | 8
 443  * +----------------+----------------+----------------+----------------+
 444  * |                               major                               | 12
 445  * +----------------+----------------+----------------+----------------+
 446  * |                               minor                               | 16
 447  * +----------------+----------------+----------------+----------------+
 448  * |                             reserved                              | 20
 449  * +----------------+----------------+----------------+----------------+
 450  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 451  * +----------------+----------------+----------------+----------------+
 452  * |                             reserved                              | 40
 453  * +----------------+----------------+----------------+----------------+
 454  *
 455  * major - unt32_t, length of the major axis, pixels
 456  * minor - unt32_t, length of the minor axis, pixels
 457  *
 458  * Multi-touch orientation event - touch point's shape has changed
 459  * its orientation: calculated as a clockwise angle between the major axis
 460  * of the ellipse and positive Y axis in degrees, [-180; +180].
 461  *         0                1                 2               3        octet
 462  * +----------------+----------------+----------------+----------------+
 463  * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
 464  * +----------------+----------------+----------------+----------------+
 465  * |                             reserved                              | 8
 466  * +----------------+----------------+----------------+----------------+
 467  * |           orientation           |            reserved             | 12
 468  * +----------------+----------------+----------------+----------------+
 469  * |                             reserved                              | 16
 470  * +----------------+----------------+----------------+----------------+
 471  * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
 472  * +----------------+----------------+----------------+----------------+
 473  * |                             reserved                              | 40
 474  * +----------------+----------------+----------------+----------------+
 475  *
 476  * orientation - int16_t, clockwise angle of the major axis
 477  */
 478
 479 struct xenkbd_mtouch {
 480         uint8_t type;                   /* XENKBD_TYPE_MTOUCH */
 481         uint8_t event_type;             /* XENKBD_MT_EV_??? */
 482         uint8_t contact_id;
 483         uint8_t reserved[5];            /* reserved for the future use */
 484         union {
 485                 struct {
 486                         int32_t abs_x;  /* absolute X position, pixels */
 487                         int32_t abs_y;  /* absolute Y position, pixels */
 488                 } pos;
 489                 struct {
 490                         uint32_t major; /* length of the major axis, pixels */
 491                         uint32_t minor; /* length of the minor axis, pixels */
 492                 } shape;
 493                 int16_t orientation;    /* clockwise angle of the major axis */
 494         } u;
 495 };
 496
 497 #define XENKBD_IN_EVENT_SIZE 40
 498
 499 union xenkbd_in_event {
 500         uint8_t type;
 501         struct xenkbd_motion motion;
 502         struct xenkbd_key key;
 503         struct xenkbd_position pos;
 504         struct xenkbd_mtouch mtouch;
 505         char pad[XENKBD_IN_EVENT_SIZE];
 506 };
 507
 508 /*
 509  *****************************************************************************
 510  *                            Frontend to backend events
 511  *****************************************************************************
 512  *
 513  * Out events may be sent only when requested by backend, and receipt
 514  * of an unknown out event is an error.
 515  * No out events currently defined.
 516
 517  * All event packets have the same length (40 octets)
 518  * All event packets have common header:
 519  *          0         octet
 520  * +-----------------+
 521  * |       type      |
 522  * +-----------------+
 523  * type - uint8_t, event code
 524  */
 525
 526 #define XENKBD_OUT_EVENT_SIZE 40
 527
 528 union xenkbd_out_event {
 529         uint8_t type;
 530         char pad[XENKBD_OUT_EVENT_SIZE];
 531 };
 532
 533 /*
 534  *****************************************************************************
 535  *                            Shared page
 536  *****************************************************************************
 537  */
 538
 539 #define XENKBD_IN_RING_SIZE 2048
 540 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
 541 #define XENKBD_IN_RING_OFFS 1024
 542 #define XENKBD_IN_RING(page) \
 543         ((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
 544 #define XENKBD_IN_RING_REF(page, idx) \
 545         (XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
 546
 547 #define XENKBD_OUT_RING_SIZE 1024
 548 #define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
 549 #define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
 550 #define XENKBD_OUT_RING(page) \
 551         ((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
 552 #define XENKBD_OUT_RING_REF(page, idx) \
 553         (XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
 554
 555 struct xenkbd_page {
 556         uint32_t in_cons, in_prod;
 557         uint32_t out_cons, out_prod;
 558 };
 559
 560 #endif /* __XEN_PUBLIC_IO_KBDIF_H__ */