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/slab.h>
  21
  22 #include <asm/xen/hypervisor.h>
  23
  24 #include <xen/xen.h>
  25 #include <xen/events.h>
  26 #include <xen/page.h>
  27 #include <xen/grant_table.h>
  28 #include <xen/interface/grant_table.h>
  29 #include <xen/interface/io/fbif.h>
  30 #include <xen/interface/io/kbdif.h>
  31 #include <xen/xenbus.h>
  32 #include <xen/platform_pci.h>
  33
  34 struct xenkbd_info {
  35         struct input_dev *kbd;
  36         struct input_dev *ptr;
  37         struct xenkbd_page *page;
  38         int gref;
  39         int irq;
  40         struct xenbus_device *xbdev;
  41         char phys[32];
  42 };
  43
  44 enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
  45 static int ptr_size[KPARAM_CNT] = { XENFB_WIDTH, XENFB_HEIGHT };
  46 module_param_array(ptr_size, int, NULL, 0444);
  47 MODULE_PARM_DESC(ptr_size,
  48         "Pointing device width, height in pixels (default 800,600)");
  49
  50 static int xenkbd_remove(struct xenbus_device *);
  51 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
  52 static void xenkbd_disconnect_backend(struct xenkbd_info *);
  53
  54 /*
  55  * Note: if you need to send out events, see xenfb_do_update() for how
  56  * to do that.
  57  */
  58
  59 static irqreturn_t input_handler(int rq, void *dev_id)
  60 {
  61         struct xenkbd_info *info = dev_id;
  62         struct xenkbd_page *page = info->page;
  63         __u32 cons, prod;
  64
  65         prod = page->in_prod;
  66         if (prod == page->in_cons)
  67                 return IRQ_HANDLED;
  68         rmb();                  /* ensure we see ring contents up to prod */
  69         for (cons = page->in_cons; cons != prod; cons++) {
  70                 union xenkbd_in_event *event;
  71                 struct input_dev *dev;
  72                 event = &XENKBD_IN_RING_REF(page, cons);
  73
  74                 dev = info->ptr;
  75                 switch (event->type) {
  76                 case XENKBD_TYPE_MOTION:
  77                         input_report_rel(dev, REL_X, event->motion.rel_x);
  78                         input_report_rel(dev, REL_Y, event->motion.rel_y);
  79                         if (event->motion.rel_z)
  80                                 input_report_rel(dev, REL_WHEEL,
  81                                                  -event->motion.rel_z);
  82                         break;
  83                 case XENKBD_TYPE_KEY:
  84                         dev = NULL;
  85                         if (test_bit(event->key.keycode, info->kbd->keybit))
  86                                 dev = info->kbd;
  87                         if (test_bit(event->key.keycode, info->ptr->keybit))
  88                                 dev = info->ptr;
  89                         if (dev)
  90                                 input_report_key(dev, event->key.keycode,
  91                                                  event->key.pressed);
  92                         else
  93                                 pr_warn("unhandled keycode 0x%x\n",
  94                                         event->key.keycode);
  95                         break;
  96                 case XENKBD_TYPE_POS:
  97                         input_report_abs(dev, ABS_X, event->pos.abs_x);
  98                         input_report_abs(dev, ABS_Y, event->pos.abs_y);
  99                         if (event->pos.rel_z)
 100                                 input_report_rel(dev, REL_WHEEL,
 101                                                  -event->pos.rel_z);
 102                         break;
 103                 }
 104                 if (dev)
 105                         input_sync(dev);
 106         }
 107         mb();                   /* ensure we got ring contents */
 108         page->in_cons = cons;
 109         notify_remote_via_irq(info->irq);
 110
 111         return IRQ_HANDLED;
 112 }
 113
 114 static int xenkbd_probe(struct xenbus_device *dev,
 115                                   const struct xenbus_device_id *id)
 116 {
 117         int ret, i;
 118         unsigned int abs;
 119         struct xenkbd_info *info;
 120         struct input_dev *kbd, *ptr;
 121
 122         info = kzalloc(sizeof(*info), GFP_KERNEL);
 123         if (!info) {
 124                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
 125                 return -ENOMEM;
 126         }
 127         dev_set_drvdata(&dev->dev, info);
 128         info->xbdev = dev;
 129         info->irq = -1;
 130         info->gref = -1;
 131         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
 132
 133         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 134         if (!info->page)
 135                 goto error_nomem;
 136
 137         /* Set input abs params to match backend screen res */
 138         abs = xenbus_read_unsigned(dev->otherend, "feature-abs-pointer", 0);
 139         ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend, "width",
 140                                                   ptr_size[KPARAM_X]);
 141         ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend, "height",
 142                                                   ptr_size[KPARAM_Y]);
 143         if (abs) {
 144                 ret = xenbus_write(XBT_NIL, dev->nodename,
 145                                    "request-abs-pointer", "1");
 146                 if (ret) {
 147                         pr_warn("xenkbd: can't request abs-pointer\n");
 148                         abs = 0;
 149                 }
 150         }
 151
 152         /* keyboard */
 153         kbd = input_allocate_device();
 154         if (!kbd)
 155                 goto error_nomem;
 156         kbd->name = "Xen Virtual Keyboard";
 157         kbd->phys = info->phys;
 158         kbd->id.bustype = BUS_PCI;
 159         kbd->id.vendor = 0x5853;
 160         kbd->id.product = 0xffff;
 161
 162         __set_bit(EV_KEY, kbd->evbit);
 163         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 164                 __set_bit(i, kbd->keybit);
 165         for (i = KEY_OK; i < KEY_MAX; i++)
 166                 __set_bit(i, kbd->keybit);
 167
 168         ret = input_register_device(kbd);
 169         if (ret) {
 170                 input_free_device(kbd);
 171                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 172                 goto error;
 173         }
 174         info->kbd = kbd;
 175
 176         /* pointing device */
 177         ptr = input_allocate_device();
 178         if (!ptr)
 179                 goto error_nomem;
 180         ptr->name = "Xen Virtual Pointer";
 181         ptr->phys = info->phys;
 182         ptr->id.bustype = BUS_PCI;
 183         ptr->id.vendor = 0x5853;
 184         ptr->id.product = 0xfffe;
 185
 186         if (abs) {
 187                 __set_bit(EV_ABS, ptr->evbit);
 188                 input_set_abs_params(ptr, ABS_X, 0, ptr_size[KPARAM_X], 0, 0);
 189                 input_set_abs_params(ptr, ABS_Y, 0, ptr_size[KPARAM_Y], 0, 0);
 190         } else {
 191                 input_set_capability(ptr, EV_REL, REL_X);
 192                 input_set_capability(ptr, EV_REL, REL_Y);
 193         }
 194         input_set_capability(ptr, EV_REL, REL_WHEEL);
 195
 196         __set_bit(EV_KEY, ptr->evbit);
 197         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 198                 __set_bit(i, ptr->keybit);
 199
 200         ret = input_register_device(ptr);
 201         if (ret) {
 202                 input_free_device(ptr);
 203                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 204                 goto error;
 205         }
 206         info->ptr = ptr;
 207
 208         ret = xenkbd_connect_backend(dev, info);
 209         if (ret < 0)
 210                 goto error;
 211
 212         return 0;
 213
 214  error_nomem:
 215         ret = -ENOMEM;
 216         xenbus_dev_fatal(dev, ret, "allocating device memory");
 217  error:
 218         xenkbd_remove(dev);
 219         return ret;
 220 }
 221
 222 static int xenkbd_resume(struct xenbus_device *dev)
 223 {
 224         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 225
 226         xenkbd_disconnect_backend(info);
 227         memset(info->page, 0, PAGE_SIZE);
 228         return xenkbd_connect_backend(dev, info);
 229 }
 230
 231 static int xenkbd_remove(struct xenbus_device *dev)
 232 {
 233         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 234
 235         xenkbd_disconnect_backend(info);
 236         if (info->kbd)
 237                 input_unregister_device(info->kbd);
 238         if (info->ptr)
 239                 input_unregister_device(info->ptr);
 240         free_page((unsigned long)info->page);
 241         kfree(info);
 242         return 0;
 243 }
 244
 245 static int xenkbd_connect_backend(struct xenbus_device *dev,
 246                                   struct xenkbd_info *info)
 247 {
 248         int ret, evtchn;
 249         struct xenbus_transaction xbt;
 250
 251         ret = gnttab_grant_foreign_access(dev->otherend_id,
 252                                           virt_to_gfn(info->page), 0);
 253         if (ret < 0)
 254                 return ret;
 255         info->gref = ret;
 256
 257         ret = xenbus_alloc_evtchn(dev, &evtchn);
 258         if (ret)
 259                 goto error_grant;
 260         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 261                                         0, dev->devicetype, info);
 262         if (ret < 0) {
 263                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 264                 goto error_evtchan;
 265         }
 266         info->irq = ret;
 267
 268  again:
 269         ret = xenbus_transaction_start(&xbt);
 270         if (ret) {
 271                 xenbus_dev_fatal(dev, ret, "starting transaction");
 272                 goto error_irqh;
 273         }
 274         ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
 275                             virt_to_gfn(info->page));
 276         if (ret)
 277                 goto error_xenbus;
 278         ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
 279         if (ret)
 280                 goto error_xenbus;
 281         ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
 282                             evtchn);
 283         if (ret)
 284                 goto error_xenbus;
 285         ret = xenbus_transaction_end(xbt, 0);
 286         if (ret) {
 287                 if (ret == -EAGAIN)
 288                         goto again;
 289                 xenbus_dev_fatal(dev, ret, "completing transaction");
 290                 goto error_irqh;
 291         }
 292
 293         xenbus_switch_state(dev, XenbusStateInitialised);
 294         return 0;
 295
 296  error_xenbus:
 297         xenbus_transaction_end(xbt, 1);
 298         xenbus_dev_fatal(dev, ret, "writing xenstore");
 299  error_irqh:
 300         unbind_from_irqhandler(info->irq, info);
 301         info->irq = -1;
 302  error_evtchan:
 303         xenbus_free_evtchn(dev, evtchn);
 304  error_grant:
 305         gnttab_end_foreign_access(info->gref, 0, 0UL);
 306         info->gref = -1;
 307         return ret;
 308 }
 309
 310 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 311 {
 312         if (info->irq >= 0)
 313                 unbind_from_irqhandler(info->irq, info);
 314         info->irq = -1;
 315         if (info->gref >= 0)
 316                 gnttab_end_foreign_access(info->gref, 0, 0UL);
 317         info->gref = -1;
 318 }
 319
 320 static void xenkbd_backend_changed(struct xenbus_device *dev,
 321                                    enum xenbus_state backend_state)
 322 {
 323         switch (backend_state) {
 324         case XenbusStateInitialising:
 325         case XenbusStateInitialised:
 326         case XenbusStateReconfiguring:
 327         case XenbusStateReconfigured:
 328         case XenbusStateUnknown:
 329                 break;
 330
 331         case XenbusStateInitWait:
 332                 xenbus_switch_state(dev, XenbusStateConnected);
 333                 break;
 334
 335         case XenbusStateConnected:
 336                 /*
 337                  * Work around xenbus race condition: If backend goes
 338                  * through InitWait to Connected fast enough, we can
 339                  * get Connected twice here.
 340                  */
 341                 if (dev->state != XenbusStateConnected)
 342                         xenbus_switch_state(dev, XenbusStateConnected);
 343                 break;
 344
 345         case XenbusStateClosed:
 346                 if (dev->state == XenbusStateClosed)
 347                         break;
 348                 /* Missed the backend's CLOSING state -- fallthrough */
 349         case XenbusStateClosing:
 350                 xenbus_frontend_closed(dev);
 351                 break;
 352         }
 353 }
 354
 355 static const struct xenbus_device_id xenkbd_ids[] = {
 356         { "vkbd" },
 357         { "" }
 358 };
 359
 360 static struct xenbus_driver xenkbd_driver = {
 361         .ids = xenkbd_ids,
 362         .probe = xenkbd_probe,
 363         .remove = xenkbd_remove,
 364         .resume = xenkbd_resume,
 365         .otherend_changed = xenkbd_backend_changed,
 366 };
 367
 368 static int __init xenkbd_init(void)
 369 {
 370         if (!xen_domain())
 371                 return -ENODEV;
 372
 373         /* Nothing to do if running in dom0. */
 374         if (xen_initial_domain())
 375                 return -ENODEV;
 376
 377         if (!xen_has_pv_devices())
 378                 return -ENODEV;
 379
 380         return xenbus_register_frontend(&xenkbd_driver);
 381 }
 382
 383 static void __exit xenkbd_cleanup(void)
 384 {
 385         xenbus_unregister_driver(&xenkbd_driver);
 386 }
 387
 388 module_init(xenkbd_init);
 389 module_exit(xenkbd_cleanup);
 390
 391 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 392 MODULE_LICENSE("GPL");
 393 MODULE_ALIAS("xen:vkbd");