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         int value = key->pressed;
  88
  89         if (test_bit(key->keycode, info->ptr->keybit)) {
  90                 dev = info->ptr;
  91         } else if (test_bit(key->keycode, info->kbd->keybit)) {
  92                 dev = info->kbd;
  93                 if (key->pressed && test_bit(key->keycode, info->kbd->key))
  94                         value = 2; /* Mark as autorepeat */
  95         } else {
  96                 pr_warn("unhandled keycode 0x%x\n", key->keycode);
  97                 return;
  98         }
  99
 100         input_event(dev, EV_KEY, key->keycode, value);
 101         input_sync(dev);
 102 }
 103
 104 static void xenkbd_handle_mt_event(struct xenkbd_info *info,
 105                                    struct xenkbd_mtouch *mtouch)
 106 {
 107         if (unlikely(!info->mtouch))
 108                 return;
 109
 110         if (mtouch->contact_id != info->mtouch_cur_contact_id) {
 111                 info->mtouch_cur_contact_id = mtouch->contact_id;
 112                 input_mt_slot(info->mtouch, mtouch->contact_id);
 113         }
 114
 115         switch (mtouch->event_type) {
 116         case XENKBD_MT_EV_DOWN:
 117                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, true);
 118                 /* fall through */
 119
 120         case XENKBD_MT_EV_MOTION:
 121                 input_report_abs(info->mtouch, ABS_MT_POSITION_X,
 122                                  mtouch->u.pos.abs_x);
 123                 input_report_abs(info->mtouch, ABS_MT_POSITION_Y,
 124                                  mtouch->u.pos.abs_y);
 125                 break;
 126
 127         case XENKBD_MT_EV_SHAPE:
 128                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MAJOR,
 129                                  mtouch->u.shape.major);
 130                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MINOR,
 131                                  mtouch->u.shape.minor);
 132                 break;
 133
 134         case XENKBD_MT_EV_ORIENT:
 135                 input_report_abs(info->mtouch, ABS_MT_ORIENTATION,
 136                                  mtouch->u.orientation);
 137                 break;
 138
 139         case XENKBD_MT_EV_UP:
 140                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, false);
 141                 break;
 142
 143         case XENKBD_MT_EV_SYN:
 144                 input_mt_sync_frame(info->mtouch);
 145                 input_sync(info->mtouch);
 146                 break;
 147         }
 148 }
 149
 150 static void xenkbd_handle_event(struct xenkbd_info *info,
 151                                 union xenkbd_in_event *event)
 152 {
 153         switch (event->type) {
 154         case XENKBD_TYPE_MOTION:
 155                 xenkbd_handle_motion_event(info, &event->motion);
 156                 break;
 157
 158         case XENKBD_TYPE_KEY:
 159                 xenkbd_handle_key_event(info, &event->key);
 160                 break;
 161
 162         case XENKBD_TYPE_POS:
 163                 xenkbd_handle_position_event(info, &event->pos);
 164                 break;
 165
 166         case XENKBD_TYPE_MTOUCH:
 167                 xenkbd_handle_mt_event(info, &event->mtouch);
 168                 break;
 169         }
 170 }
 171
 172 static irqreturn_t input_handler(int rq, void *dev_id)
 173 {
 174         struct xenkbd_info *info = dev_id;
 175         struct xenkbd_page *page = info->page;
 176         __u32 cons, prod;
 177
 178         prod = page->in_prod;
 179         if (prod == page->in_cons)
 180                 return IRQ_HANDLED;
 181         rmb();                  /* ensure we see ring contents up to prod */
 182         for (cons = page->in_cons; cons != prod; cons++)
 183                 xenkbd_handle_event(info, &XENKBD_IN_RING_REF(page, cons));
 184         mb();                   /* ensure we got ring contents */
 185         page->in_cons = cons;
 186         notify_remote_via_irq(info->irq);
 187
 188         return IRQ_HANDLED;
 189 }
 190
 191 static int xenkbd_probe(struct xenbus_device *dev,
 192                                   const struct xenbus_device_id *id)
 193 {
 194         int ret, i;
 195         unsigned int abs, touch;
 196         struct xenkbd_info *info;
 197         struct input_dev *kbd, *ptr, *mtouch;
 198
 199         info = kzalloc(sizeof(*info), GFP_KERNEL);
 200         if (!info) {
 201                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
 202                 return -ENOMEM;
 203         }
 204         dev_set_drvdata(&dev->dev, info);
 205         info->xbdev = dev;
 206         info->irq = -1;
 207         info->gref = -1;
 208         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
 209
 210         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 211         if (!info->page)
 212                 goto error_nomem;
 213
 214         /* Set input abs params to match backend screen res */
 215         abs = xenbus_read_unsigned(dev->otherend,
 216                                    XENKBD_FIELD_FEAT_ABS_POINTER, 0);
 217         ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend,
 218                                                   XENKBD_FIELD_WIDTH,
 219                                                   ptr_size[KPARAM_X]);
 220         ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend,
 221                                                   XENKBD_FIELD_HEIGHT,
 222                                                   ptr_size[KPARAM_Y]);
 223         if (abs) {
 224                 ret = xenbus_write(XBT_NIL, dev->nodename,
 225                                    XENKBD_FIELD_REQ_ABS_POINTER, "1");
 226                 if (ret) {
 227                         pr_warn("xenkbd: can't request abs-pointer\n");
 228                         abs = 0;
 229                 }
 230         }
 231
 232         touch = xenbus_read_unsigned(dev->otherend,
 233                                      XENKBD_FIELD_FEAT_MTOUCH, 0);
 234         if (touch) {
 235                 ret = xenbus_write(XBT_NIL, dev->nodename,
 236                                    XENKBD_FIELD_REQ_MTOUCH, "1");
 237                 if (ret) {
 238                         pr_warn("xenkbd: can't request multi-touch");
 239                         touch = 0;
 240                 }
 241         }
 242
 243         /* keyboard */
 244         kbd = input_allocate_device();
 245         if (!kbd)
 246                 goto error_nomem;
 247         kbd->name = "Xen Virtual Keyboard";
 248         kbd->phys = info->phys;
 249         kbd->id.bustype = BUS_PCI;
 250         kbd->id.vendor = 0x5853;
 251         kbd->id.product = 0xffff;
 252
 253         __set_bit(EV_KEY, kbd->evbit);
 254         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 255                 __set_bit(i, kbd->keybit);
 256         for (i = KEY_OK; i < KEY_MAX; i++)
 257                 __set_bit(i, kbd->keybit);
 258
 259         ret = input_register_device(kbd);
 260         if (ret) {
 261                 input_free_device(kbd);
 262                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 263                 goto error;
 264         }
 265         info->kbd = kbd;
 266
 267         /* pointing device */
 268         ptr = input_allocate_device();
 269         if (!ptr)
 270                 goto error_nomem;
 271         ptr->name = "Xen Virtual Pointer";
 272         ptr->phys = info->phys;
 273         ptr->id.bustype = BUS_PCI;
 274         ptr->id.vendor = 0x5853;
 275         ptr->id.product = 0xfffe;
 276
 277         if (abs) {
 278                 __set_bit(EV_ABS, ptr->evbit);
 279                 input_set_abs_params(ptr, ABS_X, 0, ptr_size[KPARAM_X], 0, 0);
 280                 input_set_abs_params(ptr, ABS_Y, 0, ptr_size[KPARAM_Y], 0, 0);
 281         } else {
 282                 input_set_capability(ptr, EV_REL, REL_X);
 283                 input_set_capability(ptr, EV_REL, REL_Y);
 284         }
 285         input_set_capability(ptr, EV_REL, REL_WHEEL);
 286
 287         __set_bit(EV_KEY, ptr->evbit);
 288         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 289                 __set_bit(i, ptr->keybit);
 290
 291         ret = input_register_device(ptr);
 292         if (ret) {
 293                 input_free_device(ptr);
 294                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 295                 goto error;
 296         }
 297         info->ptr = ptr;
 298
 299         /* multi-touch device */
 300         if (touch) {
 301                 int num_cont, width, height;
 302
 303                 mtouch = input_allocate_device();
 304                 if (!mtouch)
 305                         goto error_nomem;
 306
 307                 num_cont = xenbus_read_unsigned(info->xbdev->otherend,
 308                                                 XENKBD_FIELD_MT_NUM_CONTACTS,
 309                                                 1);
 310                 width = xenbus_read_unsigned(info->xbdev->otherend,
 311                                              XENKBD_FIELD_MT_WIDTH,
 312                                              XENFB_WIDTH);
 313                 height = xenbus_read_unsigned(info->xbdev->otherend,
 314                                               XENKBD_FIELD_MT_HEIGHT,
 315                                               XENFB_HEIGHT);
 316
 317                 mtouch->name = "Xen Virtual Multi-touch";
 318                 mtouch->phys = info->phys;
 319                 mtouch->id.bustype = BUS_PCI;
 320                 mtouch->id.vendor = 0x5853;
 321                 mtouch->id.product = 0xfffd;
 322
 323                 input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
 324                                      0, 255, 0, 0);
 325                 input_set_abs_params(mtouch, ABS_MT_POSITION_X,
 326                                      0, width, 0, 0);
 327                 input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
 328                                      0, height, 0, 0);
 329
 330                 ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
 331                 if (ret) {
 332                         input_free_device(mtouch);
 333                         xenbus_dev_fatal(info->xbdev, ret,
 334                                          "input_mt_init_slots");
 335                         goto error;
 336                 }
 337
 338                 ret = input_register_device(mtouch);
 339                 if (ret) {
 340                         input_free_device(mtouch);
 341                         xenbus_dev_fatal(info->xbdev, ret,
 342                                          "input_register_device(mtouch)");
 343                         goto error;
 344                 }
 345                 info->mtouch_cur_contact_id = -1;
 346                 info->mtouch = mtouch;
 347         }
 348
 349         ret = xenkbd_connect_backend(dev, info);
 350         if (ret < 0)
 351                 goto error;
 352
 353         return 0;
 354
 355  error_nomem:
 356         ret = -ENOMEM;
 357         xenbus_dev_fatal(dev, ret, "allocating device memory");
 358  error:
 359         xenkbd_remove(dev);
 360         return ret;
 361 }
 362
 363 static int xenkbd_resume(struct xenbus_device *dev)
 364 {
 365         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 366
 367         xenkbd_disconnect_backend(info);
 368         memset(info->page, 0, PAGE_SIZE);
 369         return xenkbd_connect_backend(dev, info);
 370 }
 371
 372 static int xenkbd_remove(struct xenbus_device *dev)
 373 {
 374         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 375
 376         xenkbd_disconnect_backend(info);
 377         if (info->kbd)
 378                 input_unregister_device(info->kbd);
 379         if (info->ptr)
 380                 input_unregister_device(info->ptr);
 381         if (info->mtouch)
 382                 input_unregister_device(info->mtouch);
 383         free_page((unsigned long)info->page);
 384         kfree(info);
 385         return 0;
 386 }
 387
 388 static int xenkbd_connect_backend(struct xenbus_device *dev,
 389                                   struct xenkbd_info *info)
 390 {
 391         int ret, evtchn;
 392         struct xenbus_transaction xbt;
 393
 394         ret = gnttab_grant_foreign_access(dev->otherend_id,
 395                                           virt_to_gfn(info->page), 0);
 396         if (ret < 0)
 397                 return ret;
 398         info->gref = ret;
 399
 400         ret = xenbus_alloc_evtchn(dev, &evtchn);
 401         if (ret)
 402                 goto error_grant;
 403         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 404                                         0, dev->devicetype, info);
 405         if (ret < 0) {
 406                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 407                 goto error_evtchan;
 408         }
 409         info->irq = ret;
 410
 411  again:
 412         ret = xenbus_transaction_start(&xbt);
 413         if (ret) {
 414                 xenbus_dev_fatal(dev, ret, "starting transaction");
 415                 goto error_irqh;
 416         }
 417         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_REF, "%lu",
 418                             virt_to_gfn(info->page));
 419         if (ret)
 420                 goto error_xenbus;
 421         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_GREF,
 422                             "%u", info->gref);
 423         if (ret)
 424                 goto error_xenbus;
 425         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_EVT_CHANNEL, "%u",
 426                             evtchn);
 427         if (ret)
 428                 goto error_xenbus;
 429         ret = xenbus_transaction_end(xbt, 0);
 430         if (ret) {
 431                 if (ret == -EAGAIN)
 432                         goto again;
 433                 xenbus_dev_fatal(dev, ret, "completing transaction");
 434                 goto error_irqh;
 435         }
 436
 437         xenbus_switch_state(dev, XenbusStateInitialised);
 438         return 0;
 439
 440  error_xenbus:
 441         xenbus_transaction_end(xbt, 1);
 442         xenbus_dev_fatal(dev, ret, "writing xenstore");
 443  error_irqh:
 444         unbind_from_irqhandler(info->irq, info);
 445         info->irq = -1;
 446  error_evtchan:
 447         xenbus_free_evtchn(dev, evtchn);
 448  error_grant:
 449         gnttab_end_foreign_access(info->gref, 0, 0UL);
 450         info->gref = -1;
 451         return ret;
 452 }
 453
 454 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 455 {
 456         if (info->irq >= 0)
 457                 unbind_from_irqhandler(info->irq, info);
 458         info->irq = -1;
 459         if (info->gref >= 0)
 460                 gnttab_end_foreign_access(info->gref, 0, 0UL);
 461         info->gref = -1;
 462 }
 463
 464 static void xenkbd_backend_changed(struct xenbus_device *dev,
 465                                    enum xenbus_state backend_state)
 466 {
 467         switch (backend_state) {
 468         case XenbusStateInitialising:
 469         case XenbusStateInitialised:
 470         case XenbusStateReconfiguring:
 471         case XenbusStateReconfigured:
 472         case XenbusStateUnknown:
 473                 break;
 474
 475         case XenbusStateInitWait:
 476                 xenbus_switch_state(dev, XenbusStateConnected);
 477                 break;
 478
 479         case XenbusStateConnected:
 480                 /*
 481                  * Work around xenbus race condition: If backend goes
 482                  * through InitWait to Connected fast enough, we can
 483                  * get Connected twice here.
 484                  */
 485                 if (dev->state != XenbusStateConnected)
 486                         xenbus_switch_state(dev, XenbusStateConnected);
 487                 break;
 488
 489         case XenbusStateClosed:
 490                 if (dev->state == XenbusStateClosed)
 491                         break;
 492                 /* Missed the backend's CLOSING state -- fallthrough */
 493         case XenbusStateClosing:
 494                 xenbus_frontend_closed(dev);
 495                 break;
 496         }
 497 }
 498
 499 static const struct xenbus_device_id xenkbd_ids[] = {
 500         { XENKBD_DRIVER_NAME },
 501         { "" }
 502 };
 503
 504 static struct xenbus_driver xenkbd_driver = {
 505         .ids = xenkbd_ids,
 506         .probe = xenkbd_probe,
 507         .remove = xenkbd_remove,
 508         .resume = xenkbd_resume,
 509         .otherend_changed = xenkbd_backend_changed,
 510 };
 511
 512 static int __init xenkbd_init(void)
 513 {
 514         if (!xen_domain())
 515                 return -ENODEV;
 516
 517         /* Nothing to do if running in dom0. */
 518         if (xen_initial_domain())
 519                 return -ENODEV;
 520
 521         if (!xen_has_pv_devices())
 522                 return -ENODEV;
 523
 524         return xenbus_register_frontend(&xenkbd_driver);
 525 }
 526
 527 static void __exit xenkbd_cleanup(void)
 528 {
 529         xenbus_unregister_driver(&xenkbd_driver);
 530 }
 531
 532 module_init(xenkbd_init);
 533 module_exit(xenkbd_cleanup);
 534
 535 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 536 MODULE_LICENSE("GPL");
 537 MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);