drivers/input/misc/xen-kbdfront.c

   1 /*
   2  * Xen para-virtual input device
   3  *
   4  * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
   5  * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
   6  *
   7  *  Based on linux/drivers/input/mouse/sermouse.c
   8  *
   9  *  This file is subject to the terms and conditions of the GNU General Public
  10  *  License. See the file COPYING in the main directory of this archive for
  11  *  more details.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/module.h>
  19 #include <linux/input.h>
  20 #include <linux/input/mt.h>
  21 #include <linux/slab.h>
  22
  23 #include <asm/xen/hypervisor.h>
  24
  25 #include <xen/xen.h>
  26 #include <xen/events.h>
  27 #include <xen/page.h>
  28 #include <xen/grant_table.h>
  29 #include <xen/interface/grant_table.h>
  30 #include <xen/interface/io/fbif.h>
  31 #include <xen/interface/io/kbdif.h>
  32 #include <xen/xenbus.h>
  33 #include <xen/platform_pci.h>
  34
  35 struct xenkbd_info {
  36         struct input_dev *kbd;
  37         struct input_dev *ptr;
  38         struct input_dev *mtouch;
  39         struct xenkbd_page *page;
  40         int gref;
  41         int irq;
  42         struct xenbus_device *xbdev;
  43         char phys[32];
  44         /* current MT slot/contact ID we are injecting events in */
  45         int mtouch_cur_contact_id;
  46 };
  47
  48 enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
  49 static int ptr_size[KPARAM_CNT] = { XENFB_WIDTH, XENFB_HEIGHT };
  50 module_param_array(ptr_size, int, NULL, 0444);
  51 MODULE_PARM_DESC(ptr_size,
  52         "Pointing device width, height in pixels (default 800,600)");
  53
  54 static int xenkbd_remove(struct xenbus_device *);
  55 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
  56 static void xenkbd_disconnect_backend(struct xenkbd_info *);
  57
  58 /*
  59  * Note: if you need to send out events, see xenfb_do_update() for how
  60  * to do that.
  61  */
  62
  63 static void xenkbd_handle_motion_event(struct xenkbd_info *info,
  64                                        struct xenkbd_motion *motion)
  65 {
  66         if (unlikely(!info->ptr))
  67                 return;
  68
  69         input_report_rel(info->ptr, REL_X, motion->rel_x);
  70         input_report_rel(info->ptr, REL_Y, motion->rel_y);
  71         if (motion->rel_z)
  72                 input_report_rel(info->ptr, REL_WHEEL, -motion->rel_z);
  73         input_sync(info->ptr);
  74 }
  75
  76 static void xenkbd_handle_position_event(struct xenkbd_info *info,
  77                                          struct xenkbd_position *pos)
  78 {
  79         if (unlikely(!info->ptr))
  80                 return;
  81
  82         input_report_abs(info->ptr, ABS_X, pos->abs_x);
  83         input_report_abs(info->ptr, ABS_Y, pos->abs_y);
  84         if (pos->rel_z)
  85                 input_report_rel(info->ptr, REL_WHEEL, -pos->rel_z);
  86         input_sync(info->ptr);
  87 }
  88
  89 static void xenkbd_handle_key_event(struct xenkbd_info *info,
  90                                     struct xenkbd_key *key)
  91 {
  92         struct input_dev *dev;
  93         int value = key->pressed;
  94
  95         if (test_bit(key->keycode, info->ptr->keybit)) {
  96                 dev = info->ptr;
  97         } else if (test_bit(key->keycode, info->kbd->keybit)) {
  98                 dev = info->kbd;
  99                 if (key->pressed && test_bit(key->keycode, info->kbd->key))
 100                         value = 2; /* Mark as autorepeat */
 101         } else {
 102                 pr_warn("unhandled keycode 0x%x\n", key->keycode);
 103                 return;
 104         }
 105
 106         if (unlikely(!dev))
 107                 return;
 108
 109         input_event(dev, EV_KEY, key->keycode, value);
 110         input_sync(dev);
 111 }
 112
 113 static void xenkbd_handle_mt_event(struct xenkbd_info *info,
 114                                    struct xenkbd_mtouch *mtouch)
 115 {
 116         if (unlikely(!info->mtouch))
 117                 return;
 118
 119         if (mtouch->contact_id != info->mtouch_cur_contact_id) {
 120                 info->mtouch_cur_contact_id = mtouch->contact_id;
 121                 input_mt_slot(info->mtouch, mtouch->contact_id);
 122         }
 123
 124         switch (mtouch->event_type) {
 125         case XENKBD_MT_EV_DOWN:
 126                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, true);
 127                 fallthrough;
 128
 129         case XENKBD_MT_EV_MOTION:
 130                 input_report_abs(info->mtouch, ABS_MT_POSITION_X,
 131                                  mtouch->u.pos.abs_x);
 132                 input_report_abs(info->mtouch, ABS_MT_POSITION_Y,
 133                                  mtouch->u.pos.abs_y);
 134                 break;
 135
 136         case XENKBD_MT_EV_SHAPE:
 137                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MAJOR,
 138                                  mtouch->u.shape.major);
 139                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MINOR,
 140                                  mtouch->u.shape.minor);
 141                 break;
 142
 143         case XENKBD_MT_EV_ORIENT:
 144                 input_report_abs(info->mtouch, ABS_MT_ORIENTATION,
 145                                  mtouch->u.orientation);
 146                 break;
 147
 148         case XENKBD_MT_EV_UP:
 149                 input_mt_report_slot_inactive(info->mtouch);
 150                 break;
 151
 152         case XENKBD_MT_EV_SYN:
 153                 input_mt_sync_frame(info->mtouch);
 154                 input_sync(info->mtouch);
 155                 break;
 156         }
 157 }
 158
 159 static void xenkbd_handle_event(struct xenkbd_info *info,
 160                                 union xenkbd_in_event *event)
 161 {
 162         switch (event->type) {
 163         case XENKBD_TYPE_MOTION:
 164                 xenkbd_handle_motion_event(info, &event->motion);
 165                 break;
 166
 167         case XENKBD_TYPE_KEY:
 168                 xenkbd_handle_key_event(info, &event->key);
 169                 break;
 170
 171         case XENKBD_TYPE_POS:
 172                 xenkbd_handle_position_event(info, &event->pos);
 173                 break;
 174
 175         case XENKBD_TYPE_MTOUCH:
 176                 xenkbd_handle_mt_event(info, &event->mtouch);
 177                 break;
 178         }
 179 }
 180
 181 static irqreturn_t input_handler(int rq, void *dev_id)
 182 {
 183         struct xenkbd_info *info = dev_id;
 184         struct xenkbd_page *page = info->page;
 185         __u32 cons, prod;
 186
 187         prod = page->in_prod;
 188         if (prod == page->in_cons)
 189                 return IRQ_HANDLED;
 190         rmb();                  /* ensure we see ring contents up to prod */
 191         for (cons = page->in_cons; cons != prod; cons++)
 192                 xenkbd_handle_event(info, &XENKBD_IN_RING_REF(page, cons));
 193         mb();                   /* ensure we got ring contents */
 194         page->in_cons = cons;
 195         notify_remote_via_irq(info->irq);
 196
 197         return IRQ_HANDLED;
 198 }
 199
 200 static int xenkbd_probe(struct xenbus_device *dev,
 201                                   const struct xenbus_device_id *id)
 202 {
 203         int ret, i;
 204         bool with_mtouch, with_kbd, with_ptr;
 205         struct xenkbd_info *info;
 206         struct input_dev *kbd, *ptr, *mtouch;
 207
 208         info = kzalloc(sizeof(*info), GFP_KERNEL);
 209         if (!info) {
 210                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
 211                 return -ENOMEM;
 212         }
 213         dev_set_drvdata(&dev->dev, info);
 214         info->xbdev = dev;
 215         info->irq = -1;
 216         info->gref = -1;
 217         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
 218
 219         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 220         if (!info->page)
 221                 goto error_nomem;
 222
 223         /*
 224          * The below are reverse logic, e.g. if the feature is set, then
 225          * do not expose the corresponding virtual device.
 226          */
 227         with_kbd = !xenbus_read_unsigned(dev->otherend,
 228                                          XENKBD_FIELD_FEAT_DSBL_KEYBRD, 0);
 229
 230         with_ptr = !xenbus_read_unsigned(dev->otherend,
 231                                          XENKBD_FIELD_FEAT_DSBL_POINTER, 0);
 232
 233         /* Direct logic: if set, then create multi-touch device. */
 234         with_mtouch = xenbus_read_unsigned(dev->otherend,
 235                                            XENKBD_FIELD_FEAT_MTOUCH, 0);
 236         if (with_mtouch) {
 237                 ret = xenbus_write(XBT_NIL, dev->nodename,
 238                                    XENKBD_FIELD_REQ_MTOUCH, "1");
 239                 if (ret) {
 240                         pr_warn("xenkbd: can't request multi-touch");
 241                         with_mtouch = 0;
 242                 }
 243         }
 244
 245         /* keyboard */
 246         if (with_kbd) {
 247                 kbd = input_allocate_device();
 248                 if (!kbd)
 249                         goto error_nomem;
 250                 kbd->name = "Xen Virtual Keyboard";
 251                 kbd->phys = info->phys;
 252                 kbd->id.bustype = BUS_PCI;
 253                 kbd->id.vendor = 0x5853;
 254                 kbd->id.product = 0xffff;
 255
 256                 __set_bit(EV_KEY, kbd->evbit);
 257                 for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 258                         __set_bit(i, kbd->keybit);
 259                 for (i = KEY_OK; i < KEY_MAX; i++)
 260                         __set_bit(i, kbd->keybit);
 261
 262                 ret = input_register_device(kbd);
 263                 if (ret) {
 264                         input_free_device(kbd);
 265                         xenbus_dev_fatal(dev, ret,
 266                                          "input_register_device(kbd)");
 267                         goto error;
 268                 }
 269                 info->kbd = kbd;
 270         }
 271
 272         /* pointing device */
 273         if (with_ptr) {
 274                 unsigned int abs;
 275
 276                 /* Set input abs params to match backend screen res */
 277                 abs = xenbus_read_unsigned(dev->otherend,
 278                                            XENKBD_FIELD_FEAT_ABS_POINTER, 0);
 279                 ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend,
 280                                                           XENKBD_FIELD_WIDTH,
 281                                                           ptr_size[KPARAM_X]);
 282                 ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend,
 283                                                           XENKBD_FIELD_HEIGHT,
 284                                                           ptr_size[KPARAM_Y]);
 285                 if (abs) {
 286                         ret = xenbus_write(XBT_NIL, dev->nodename,
 287                                            XENKBD_FIELD_REQ_ABS_POINTER, "1");
 288                         if (ret) {
 289                                 pr_warn("xenkbd: can't request abs-pointer\n");
 290                                 abs = 0;
 291                         }
 292                 }
 293
 294                 ptr = input_allocate_device();
 295                 if (!ptr)
 296                         goto error_nomem;
 297                 ptr->name = "Xen Virtual Pointer";
 298                 ptr->phys = info->phys;
 299                 ptr->id.bustype = BUS_PCI;
 300                 ptr->id.vendor = 0x5853;
 301                 ptr->id.product = 0xfffe;
 302
 303                 if (abs) {
 304                         __set_bit(EV_ABS, ptr->evbit);
 305                         input_set_abs_params(ptr, ABS_X, 0,
 306                                              ptr_size[KPARAM_X], 0, 0);
 307                         input_set_abs_params(ptr, ABS_Y, 0,
 308                                              ptr_size[KPARAM_Y], 0, 0);
 309                 } else {
 310                         input_set_capability(ptr, EV_REL, REL_X);
 311                         input_set_capability(ptr, EV_REL, REL_Y);
 312                 }
 313                 input_set_capability(ptr, EV_REL, REL_WHEEL);
 314
 315                 __set_bit(EV_KEY, ptr->evbit);
 316                 for (i = BTN_LEFT; i <= BTN_TASK; i++)
 317                         __set_bit(i, ptr->keybit);
 318
 319                 ret = input_register_device(ptr);
 320                 if (ret) {
 321                         input_free_device(ptr);
 322                         xenbus_dev_fatal(dev, ret,
 323                                          "input_register_device(ptr)");
 324                         goto error;
 325                 }
 326                 info->ptr = ptr;
 327         }
 328
 329         /* multi-touch device */
 330         if (with_mtouch) {
 331                 int num_cont, width, height;
 332
 333                 mtouch = input_allocate_device();
 334                 if (!mtouch)
 335                         goto error_nomem;
 336
 337                 num_cont = xenbus_read_unsigned(info->xbdev->otherend,
 338                                                 XENKBD_FIELD_MT_NUM_CONTACTS,
 339                                                 1);
 340                 width = xenbus_read_unsigned(info->xbdev->otherend,
 341                                              XENKBD_FIELD_MT_WIDTH,
 342                                              XENFB_WIDTH);
 343                 height = xenbus_read_unsigned(info->xbdev->otherend,
 344                                               XENKBD_FIELD_MT_HEIGHT,
 345                                               XENFB_HEIGHT);
 346
 347                 mtouch->name = "Xen Virtual Multi-touch";
 348                 mtouch->phys = info->phys;
 349                 mtouch->id.bustype = BUS_PCI;
 350                 mtouch->id.vendor = 0x5853;
 351                 mtouch->id.product = 0xfffd;
 352
 353                 input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
 354                                      0, 255, 0, 0);
 355                 input_set_abs_params(mtouch, ABS_MT_POSITION_X,
 356                                      0, width, 0, 0);
 357                 input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
 358                                      0, height, 0, 0);
 359
 360                 ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
 361                 if (ret) {
 362                         input_free_device(mtouch);
 363                         xenbus_dev_fatal(info->xbdev, ret,
 364                                          "input_mt_init_slots");
 365                         goto error;
 366                 }
 367
 368                 ret = input_register_device(mtouch);
 369                 if (ret) {
 370                         input_free_device(mtouch);
 371                         xenbus_dev_fatal(info->xbdev, ret,
 372                                          "input_register_device(mtouch)");
 373                         goto error;
 374                 }
 375                 info->mtouch_cur_contact_id = -1;
 376                 info->mtouch = mtouch;
 377         }
 378
 379         if (!(with_kbd || with_ptr || with_mtouch)) {
 380                 ret = -ENXIO;
 381                 goto error;
 382         }
 383
 384         ret = xenkbd_connect_backend(dev, info);
 385         if (ret < 0)
 386                 goto error;
 387
 388         return 0;
 389
 390  error_nomem:
 391         ret = -ENOMEM;
 392         xenbus_dev_fatal(dev, ret, "allocating device memory");
 393  error:
 394         xenkbd_remove(dev);
 395         return ret;
 396 }
 397
 398 static int xenkbd_resume(struct xenbus_device *dev)
 399 {
 400         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 401
 402         xenkbd_disconnect_backend(info);
 403         memset(info->page, 0, PAGE_SIZE);
 404         return xenkbd_connect_backend(dev, info);
 405 }
 406
 407 static int xenkbd_remove(struct xenbus_device *dev)
 408 {
 409         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 410
 411         xenkbd_disconnect_backend(info);
 412         if (info->kbd)
 413                 input_unregister_device(info->kbd);
 414         if (info->ptr)
 415                 input_unregister_device(info->ptr);
 416         if (info->mtouch)
 417                 input_unregister_device(info->mtouch);
 418         free_page((unsigned long)info->page);
 419         kfree(info);
 420         return 0;
 421 }
 422
 423 static int xenkbd_connect_backend(struct xenbus_device *dev,
 424                                   struct xenkbd_info *info)
 425 {
 426         int ret, evtchn;
 427         struct xenbus_transaction xbt;
 428
 429         ret = gnttab_grant_foreign_access(dev->otherend_id,
 430                                           virt_to_gfn(info->page), 0);
 431         if (ret < 0)
 432                 return ret;
 433         info->gref = ret;
 434
 435         ret = xenbus_alloc_evtchn(dev, &evtchn);
 436         if (ret)
 437                 goto error_grant;
 438         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 439                                         0, dev->devicetype, info);
 440         if (ret < 0) {
 441                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 442                 goto error_evtchan;
 443         }
 444         info->irq = ret;
 445
 446  again:
 447         ret = xenbus_transaction_start(&xbt);
 448         if (ret) {
 449                 xenbus_dev_fatal(dev, ret, "starting transaction");
 450                 goto error_irqh;
 451         }
 452         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_REF, "%lu",
 453                             virt_to_gfn(info->page));
 454         if (ret)
 455                 goto error_xenbus;
 456         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_GREF,
 457                             "%u", info->gref);
 458         if (ret)
 459                 goto error_xenbus;
 460         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_EVT_CHANNEL, "%u",
 461                             evtchn);
 462         if (ret)
 463                 goto error_xenbus;
 464         ret = xenbus_transaction_end(xbt, 0);
 465         if (ret) {
 466                 if (ret == -EAGAIN)
 467                         goto again;
 468                 xenbus_dev_fatal(dev, ret, "completing transaction");
 469                 goto error_irqh;
 470         }
 471
 472         xenbus_switch_state(dev, XenbusStateInitialised);
 473         return 0;
 474
 475  error_xenbus:
 476         xenbus_transaction_end(xbt, 1);
 477         xenbus_dev_fatal(dev, ret, "writing xenstore");
 478  error_irqh:
 479         unbind_from_irqhandler(info->irq, info);
 480         info->irq = -1;
 481  error_evtchan:
 482         xenbus_free_evtchn(dev, evtchn);
 483  error_grant:
 484         gnttab_end_foreign_access(info->gref, 0, 0UL);
 485         info->gref = -1;
 486         return ret;
 487 }
 488
 489 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 490 {
 491         if (info->irq >= 0)
 492                 unbind_from_irqhandler(info->irq, info);
 493         info->irq = -1;
 494         if (info->gref >= 0)
 495                 gnttab_end_foreign_access(info->gref, 0, 0UL);
 496         info->gref = -1;
 497 }
 498
 499 static void xenkbd_backend_changed(struct xenbus_device *dev,
 500                                    enum xenbus_state backend_state)
 501 {
 502         switch (backend_state) {
 503         case XenbusStateInitialising:
 504         case XenbusStateInitialised:
 505         case XenbusStateReconfiguring:
 506         case XenbusStateReconfigured:
 507         case XenbusStateUnknown:
 508                 break;
 509
 510         case XenbusStateInitWait:
 511                 xenbus_switch_state(dev, XenbusStateConnected);
 512                 break;
 513
 514         case XenbusStateConnected:
 515                 /*
 516                  * Work around xenbus race condition: If backend goes
 517                  * through InitWait to Connected fast enough, we can
 518                  * get Connected twice here.
 519                  */
 520                 if (dev->state != XenbusStateConnected)
 521                         xenbus_switch_state(dev, XenbusStateConnected);
 522                 break;
 523
 524         case XenbusStateClosed:
 525                 if (dev->state == XenbusStateClosed)
 526                         break;
 527                 fallthrough;    /* Missed the backend's CLOSING state */
 528         case XenbusStateClosing:
 529                 xenbus_frontend_closed(dev);
 530                 break;
 531         }
 532 }
 533
 534 static const struct xenbus_device_id xenkbd_ids[] = {
 535         { XENKBD_DRIVER_NAME },
 536         { "" }
 537 };
 538
 539 static struct xenbus_driver xenkbd_driver = {
 540         .ids = xenkbd_ids,
 541         .probe = xenkbd_probe,
 542         .remove = xenkbd_remove,
 543         .resume = xenkbd_resume,
 544         .otherend_changed = xenkbd_backend_changed,
 545 };
 546
 547 static int __init xenkbd_init(void)
 548 {
 549         if (!xen_domain())
 550                 return -ENODEV;
 551
 552         /* Nothing to do if running in dom0. */
 553         if (xen_initial_domain())
 554                 return -ENODEV;
 555
 556         if (!xen_has_pv_devices())
 557                 return -ENODEV;
 558
 559         return xenbus_register_frontend(&xenkbd_driver);
 560 }
 561
 562 static void __exit xenkbd_cleanup(void)
 563 {
 564         xenbus_unregister_driver(&xenkbd_driver);
 565 }
 566
 567 module_init(xenkbd_init);
 568 module_exit(xenkbd_cleanup);
 569
 570 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 571 MODULE_LICENSE("GPL");
 572 MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);