linux/drivers/input/misc/xen-kbdfront.c
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   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
  35struct 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
  48enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
  49static int ptr_size[KPARAM_CNT] = { XENFB_WIDTH, XENFB_HEIGHT };
  50module_param_array(ptr_size, int, NULL, 0444);
  51MODULE_PARM_DESC(ptr_size,
  52        "Pointing device width, height in pixels (default 800,600)");
  53
  54static int xenkbd_remove(struct xenbus_device *);
  55static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
  56static 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
  63static 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
  76static 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
  89static 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
 113static 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
 159static 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
 181static 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
 200static 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
 398static 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
 407static 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
 423static 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
 489static 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
 499static 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
 534static const struct xenbus_device_id xenkbd_ids[] = {
 535        { XENKBD_DRIVER_NAME },
 536        { "" }
 537};
 538
 539static 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
 547static 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
 562static void __exit xenkbd_cleanup(void)
 563{
 564        xenbus_unregister_driver(&xenkbd_driver);
 565}
 566
 567module_init(xenkbd_init);
 568module_exit(xenkbd_cleanup);
 569
 570MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 571MODULE_LICENSE("GPL");
 572MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);
 573