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         input_report_rel(info->ptr, REL_X, motion->rel_x);
  67         input_report_rel(info->ptr, REL_Y, motion->rel_y);
  68         if (motion->rel_z)
  69                 input_report_rel(info->ptr, REL_WHEEL, -motion->rel_z);
  70         input_sync(info->ptr);
  71 }
  72
  73 static void xenkbd_handle_position_event(struct xenkbd_info *info,
  74                                          struct xenkbd_position *pos)
  75 {
  76         input_report_abs(info->ptr, ABS_X, pos->abs_x);
  77         input_report_abs(info->ptr, ABS_Y, pos->abs_y);
  78         if (pos->rel_z)
  79                 input_report_rel(info->ptr, REL_WHEEL, -pos->rel_z);
  80         input_sync(info->ptr);
  81 }
  82
  83 static void xenkbd_handle_key_event(struct xenkbd_info *info,
  84                                     struct xenkbd_key *key)
  85 {
  86         struct input_dev *dev;
  87
  88         if (test_bit(key->keycode, info->ptr->keybit)) {
  89                 dev = info->ptr;
  90         } else if (test_bit(key->keycode, info->kbd->keybit)) {
  91                 dev = info->kbd;
  92         } else {
  93                 pr_warn("unhandled keycode 0x%x\n", key->keycode);
  94                 return;
  95         }
  96
  97         input_report_key(dev, key->keycode, key->pressed);
  98         input_sync(dev);
  99 }
 100
 101 static void xenkbd_handle_mt_event(struct xenkbd_info *info,
 102                                    struct xenkbd_mtouch *mtouch)
 103 {
 104         if (unlikely(!info->mtouch))
 105                 return;
 106
 107         if (mtouch->contact_id != info->mtouch_cur_contact_id) {
 108                 info->mtouch_cur_contact_id = mtouch->contact_id;
 109                 input_mt_slot(info->mtouch, mtouch->contact_id);
 110         }
 111
 112         switch (mtouch->event_type) {
 113         case XENKBD_MT_EV_DOWN:
 114                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, true);
 115                 /* fall through */
 116
 117         case XENKBD_MT_EV_MOTION:
 118                 input_report_abs(info->mtouch, ABS_MT_POSITION_X,
 119                                  mtouch->u.pos.abs_x);
 120                 input_report_abs(info->mtouch, ABS_MT_POSITION_Y,
 121                                  mtouch->u.pos.abs_y);
 122                 break;
 123
 124         case XENKBD_MT_EV_SHAPE:
 125                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MAJOR,
 126                                  mtouch->u.shape.major);
 127                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MINOR,
 128                                  mtouch->u.shape.minor);
 129                 break;
 130
 131         case XENKBD_MT_EV_ORIENT:
 132                 input_report_abs(info->mtouch, ABS_MT_ORIENTATION,
 133                                  mtouch->u.orientation);
 134                 break;
 135
 136         case XENKBD_MT_EV_UP:
 137                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, false);
 138                 break;
 139
 140         case XENKBD_MT_EV_SYN:
 141                 input_mt_sync_frame(info->mtouch);
 142                 input_sync(info->mtouch);
 143                 break;
 144         }
 145 }
 146
 147 static void xenkbd_handle_event(struct xenkbd_info *info,
 148                                 union xenkbd_in_event *event)
 149 {
 150         switch (event->type) {
 151         case XENKBD_TYPE_MOTION:
 152                 xenkbd_handle_motion_event(info, &event->motion);
 153                 break;
 154
 155         case XENKBD_TYPE_KEY:
 156                 xenkbd_handle_key_event(info, &event->key);
 157                 break;
 158
 159         case XENKBD_TYPE_POS:
 160                 xenkbd_handle_position_event(info, &event->pos);
 161                 break;
 162
 163         case XENKBD_TYPE_MTOUCH:
 164                 xenkbd_handle_mt_event(info, &event->mtouch);
 165                 break;
 166         }
 167 }
 168
 169 static irqreturn_t input_handler(int rq, void *dev_id)
 170 {
 171         struct xenkbd_info *info = dev_id;
 172         struct xenkbd_page *page = info->page;
 173         __u32 cons, prod;
 174
 175         prod = page->in_prod;
 176         if (prod == page->in_cons)
 177                 return IRQ_HANDLED;
 178         rmb();                  /* ensure we see ring contents up to prod */
 179         for (cons = page->in_cons; cons != prod; cons++)
 180                 xenkbd_handle_event(info, &XENKBD_IN_RING_REF(page, cons));
 181         mb();                   /* ensure we got ring contents */
 182         page->in_cons = cons;
 183         notify_remote_via_irq(info->irq);
 184
 185         return IRQ_HANDLED;
 186 }
 187
 188 static int xenkbd_probe(struct xenbus_device *dev,
 189                                   const struct xenbus_device_id *id)
 190 {
 191         int ret, i;
 192         unsigned int abs, touch;
 193         struct xenkbd_info *info;
 194         struct input_dev *kbd, *ptr, *mtouch;
 195
 196         info = kzalloc(sizeof(*info), GFP_KERNEL);
 197         if (!info) {
 198                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
 199                 return -ENOMEM;
 200         }
 201         dev_set_drvdata(&dev->dev, info);
 202         info->xbdev = dev;
 203         info->irq = -1;
 204         info->gref = -1;
 205         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
 206
 207         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 208         if (!info->page)
 209                 goto error_nomem;
 210
 211         /* Set input abs params to match backend screen res */
 212         abs = xenbus_read_unsigned(dev->otherend,
 213                                    XENKBD_FIELD_FEAT_ABS_POINTER, 0);
 214         ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend,
 215                                                   XENKBD_FIELD_WIDTH,
 216                                                   ptr_size[KPARAM_X]);
 217         ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend,
 218                                                   XENKBD_FIELD_HEIGHT,
 219                                                   ptr_size[KPARAM_Y]);
 220         if (abs) {
 221                 ret = xenbus_write(XBT_NIL, dev->nodename,
 222                                    XENKBD_FIELD_REQ_ABS_POINTER, "1");
 223                 if (ret) {
 224                         pr_warn("xenkbd: can't request abs-pointer\n");
 225                         abs = 0;
 226                 }
 227         }
 228
 229         touch = xenbus_read_unsigned(dev->nodename,
 230                                      XENKBD_FIELD_FEAT_MTOUCH, 0);
 231         if (touch) {
 232                 ret = xenbus_write(XBT_NIL, dev->nodename,
 233                                    XENKBD_FIELD_REQ_MTOUCH, "1");
 234                 if (ret) {
 235                         pr_warn("xenkbd: can't request multi-touch");
 236                         touch = 0;
 237                 }
 238         }
 239
 240         /* keyboard */
 241         kbd = input_allocate_device();
 242         if (!kbd)
 243                 goto error_nomem;
 244         kbd->name = "Xen Virtual Keyboard";
 245         kbd->phys = info->phys;
 246         kbd->id.bustype = BUS_PCI;
 247         kbd->id.vendor = 0x5853;
 248         kbd->id.product = 0xffff;
 249
 250         __set_bit(EV_KEY, kbd->evbit);
 251         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 252                 __set_bit(i, kbd->keybit);
 253         for (i = KEY_OK; i < KEY_MAX; i++)
 254                 __set_bit(i, kbd->keybit);
 255
 256         ret = input_register_device(kbd);
 257         if (ret) {
 258                 input_free_device(kbd);
 259                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 260                 goto error;
 261         }
 262         info->kbd = kbd;
 263
 264         /* pointing device */
 265         ptr = input_allocate_device();
 266         if (!ptr)
 267                 goto error_nomem;
 268         ptr->name = "Xen Virtual Pointer";
 269         ptr->phys = info->phys;
 270         ptr->id.bustype = BUS_PCI;
 271         ptr->id.vendor = 0x5853;
 272         ptr->id.product = 0xfffe;
 273
 274         if (abs) {
 275                 __set_bit(EV_ABS, ptr->evbit);
 276                 input_set_abs_params(ptr, ABS_X, 0, ptr_size[KPARAM_X], 0, 0);
 277                 input_set_abs_params(ptr, ABS_Y, 0, ptr_size[KPARAM_Y], 0, 0);
 278         } else {
 279                 input_set_capability(ptr, EV_REL, REL_X);
 280                 input_set_capability(ptr, EV_REL, REL_Y);
 281         }
 282         input_set_capability(ptr, EV_REL, REL_WHEEL);
 283
 284         __set_bit(EV_KEY, ptr->evbit);
 285         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 286                 __set_bit(i, ptr->keybit);
 287
 288         ret = input_register_device(ptr);
 289         if (ret) {
 290                 input_free_device(ptr);
 291                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 292                 goto error;
 293         }
 294         info->ptr = ptr;
 295
 296         /* multi-touch device */
 297         if (touch) {
 298                 int num_cont, width, height;
 299
 300                 mtouch = input_allocate_device();
 301                 if (!mtouch)
 302                         goto error_nomem;
 303
 304                 num_cont = xenbus_read_unsigned(info->xbdev->nodename,
 305                                                 XENKBD_FIELD_MT_NUM_CONTACTS,
 306                                                 1);
 307                 width = xenbus_read_unsigned(info->xbdev->nodename,
 308                                              XENKBD_FIELD_MT_WIDTH,
 309                                              XENFB_WIDTH);
 310                 height = xenbus_read_unsigned(info->xbdev->nodename,
 311                                               XENKBD_FIELD_MT_HEIGHT,
 312                                               XENFB_HEIGHT);
 313
 314                 mtouch->name = "Xen Virtual Multi-touch";
 315                 mtouch->phys = info->phys;
 316                 mtouch->id.bustype = BUS_PCI;
 317                 mtouch->id.vendor = 0x5853;
 318                 mtouch->id.product = 0xfffd;
 319
 320                 input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
 321                                      0, 255, 0, 0);
 322                 input_set_abs_params(mtouch, ABS_MT_POSITION_X,
 323                                      0, width, 0, 0);
 324                 input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
 325                                      0, height, 0, 0);
 326                 input_set_abs_params(mtouch, ABS_MT_PRESSURE,
 327                                      0, 255, 0, 0);
 328
 329                 ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
 330                 if (ret) {
 331                         input_free_device(mtouch);
 332                         xenbus_dev_fatal(info->xbdev, ret,
 333                                          "input_mt_init_slots");
 334                         goto error;
 335                 }
 336
 337                 ret = input_register_device(mtouch);
 338                 if (ret) {
 339                         input_free_device(mtouch);
 340                         xenbus_dev_fatal(info->xbdev, ret,
 341                                          "input_register_device(mtouch)");
 342                         goto error;
 343                 }
 344                 info->mtouch_cur_contact_id = -1;
 345                 info->mtouch = mtouch;
 346         }
 347
 348         ret = xenkbd_connect_backend(dev, info);
 349         if (ret < 0)
 350                 goto error;
 351
 352         return 0;
 353
 354  error_nomem:
 355         ret = -ENOMEM;
 356         xenbus_dev_fatal(dev, ret, "allocating device memory");
 357  error:
 358         xenkbd_remove(dev);
 359         return ret;
 360 }
 361
 362 static int xenkbd_resume(struct xenbus_device *dev)
 363 {
 364         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 365
 366         xenkbd_disconnect_backend(info);
 367         memset(info->page, 0, PAGE_SIZE);
 368         return xenkbd_connect_backend(dev, info);
 369 }
 370
 371 static int xenkbd_remove(struct xenbus_device *dev)
 372 {
 373         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 374
 375         xenkbd_disconnect_backend(info);
 376         if (info->kbd)
 377                 input_unregister_device(info->kbd);
 378         if (info->ptr)
 379                 input_unregister_device(info->ptr);
 380         if (info->mtouch)
 381                 input_unregister_device(info->mtouch);
 382         free_page((unsigned long)info->page);
 383         kfree(info);
 384         return 0;
 385 }
 386
 387 static int xenkbd_connect_backend(struct xenbus_device *dev,
 388                                   struct xenkbd_info *info)
 389 {
 390         int ret, evtchn;
 391         struct xenbus_transaction xbt;
 392
 393         ret = gnttab_grant_foreign_access(dev->otherend_id,
 394                                           virt_to_gfn(info->page), 0);
 395         if (ret < 0)
 396                 return ret;
 397         info->gref = ret;
 398
 399         ret = xenbus_alloc_evtchn(dev, &evtchn);
 400         if (ret)
 401                 goto error_grant;
 402         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 403                                         0, dev->devicetype, info);
 404         if (ret < 0) {
 405                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 406                 goto error_evtchan;
 407         }
 408         info->irq = ret;
 409
 410  again:
 411         ret = xenbus_transaction_start(&xbt);
 412         if (ret) {
 413                 xenbus_dev_fatal(dev, ret, "starting transaction");
 414                 goto error_irqh;
 415         }
 416         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_REF, "%lu",
 417                             virt_to_gfn(info->page));
 418         if (ret)
 419                 goto error_xenbus;
 420         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_GREF,
 421                             "%u", info->gref);
 422         if (ret)
 423                 goto error_xenbus;
 424         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_EVT_CHANNEL, "%u",
 425                             evtchn);
 426         if (ret)
 427                 goto error_xenbus;
 428         ret = xenbus_transaction_end(xbt, 0);
 429         if (ret) {
 430                 if (ret == -EAGAIN)
 431                         goto again;
 432                 xenbus_dev_fatal(dev, ret, "completing transaction");
 433                 goto error_irqh;
 434         }
 435
 436         xenbus_switch_state(dev, XenbusStateInitialised);
 437         return 0;
 438
 439  error_xenbus:
 440         xenbus_transaction_end(xbt, 1);
 441         xenbus_dev_fatal(dev, ret, "writing xenstore");
 442  error_irqh:
 443         unbind_from_irqhandler(info->irq, info);
 444         info->irq = -1;
 445  error_evtchan:
 446         xenbus_free_evtchn(dev, evtchn);
 447  error_grant:
 448         gnttab_end_foreign_access(info->gref, 0, 0UL);
 449         info->gref = -1;
 450         return ret;
 451 }
 452
 453 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 454 {
 455         if (info->irq >= 0)
 456                 unbind_from_irqhandler(info->irq, info);
 457         info->irq = -1;
 458         if (info->gref >= 0)
 459                 gnttab_end_foreign_access(info->gref, 0, 0UL);
 460         info->gref = -1;
 461 }
 462
 463 static void xenkbd_backend_changed(struct xenbus_device *dev,
 464                                    enum xenbus_state backend_state)
 465 {
 466         switch (backend_state) {
 467         case XenbusStateInitialising:
 468         case XenbusStateInitialised:
 469         case XenbusStateReconfiguring:
 470         case XenbusStateReconfigured:
 471         case XenbusStateUnknown:
 472                 break;
 473
 474         case XenbusStateInitWait:
 475                 xenbus_switch_state(dev, XenbusStateConnected);
 476                 break;
 477
 478         case XenbusStateConnected:
 479                 /*
 480                  * Work around xenbus race condition: If backend goes
 481                  * through InitWait to Connected fast enough, we can
 482                  * get Connected twice here.
 483                  */
 484                 if (dev->state != XenbusStateConnected)
 485                         xenbus_switch_state(dev, XenbusStateConnected);
 486                 break;
 487
 488         case XenbusStateClosed:
 489                 if (dev->state == XenbusStateClosed)
 490                         break;
 491                 /* Missed the backend's CLOSING state -- fallthrough */
 492         case XenbusStateClosing:
 493                 xenbus_frontend_closed(dev);
 494                 break;
 495         }
 496 }
 497
 498 static const struct xenbus_device_id xenkbd_ids[] = {
 499         { XENKBD_DRIVER_NAME },
 500         { "" }
 501 };
 502
 503 static struct xenbus_driver xenkbd_driver = {
 504         .ids = xenkbd_ids,
 505         .probe = xenkbd_probe,
 506         .remove = xenkbd_remove,
 507         .resume = xenkbd_resume,
 508         .otherend_changed = xenkbd_backend_changed,
 509 };
 510
 511 static int __init xenkbd_init(void)
 512 {
 513         if (!xen_domain())
 514                 return -ENODEV;
 515
 516         /* Nothing to do if running in dom0. */
 517         if (xen_initial_domain())
 518                 return -ENODEV;
 519
 520         if (!xen_has_pv_devices())
 521                 return -ENODEV;
 522
 523         return xenbus_register_frontend(&xenkbd_driver);
 524 }
 525
 526 static void __exit xenkbd_cleanup(void)
 527 {
 528         xenbus_unregister_driver(&xenkbd_driver);
 529 }
 530
 531 module_init(xenkbd_init);
 532 module_exit(xenkbd_cleanup);
 533
 534 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 535 MODULE_LICENSE("GPL");
 536 MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);