drivers/input/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 /*
  15  * TODO:
  16  *
  17  * Switch to grant tables together with xen-fbfront.c.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/errno.h>
  22 #include <linux/module.h>
  23 #include <linux/input.h>
  24
  25 #include <asm/xen/hypervisor.h>
  26
  27 #include <xen/xen.h>
  28 #include <xen/events.h>
  29 #include <xen/page.h>
  30 #include <xen/interface/io/fbif.h>
  31 #include <xen/interface/io/kbdif.h>
  32 #include <xen/xenbus.h>
  33
  34 struct xenkbd_info {
  35         struct input_dev *kbd;
  36         struct input_dev *ptr;
  37         struct xenkbd_page *page;
  38         int irq;
  39         struct xenbus_device *xbdev;
  40         char phys[32];
  41 };
  42
  43 static int xenkbd_remove(struct xenbus_device *);
  44 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
  45 static void xenkbd_disconnect_backend(struct xenkbd_info *);
  46
  47 /*
  48  * Note: if you need to send out events, see xenfb_do_update() for how
  49  * to do that.
  50  */
  51
  52 static irqreturn_t input_handler(int rq, void *dev_id)
  53 {
  54         struct xenkbd_info *info = dev_id;
  55         struct xenkbd_page *page = info->page;
  56         __u32 cons, prod;
  57
  58         prod = page->in_prod;
  59         if (prod == page->in_cons)
  60                 return IRQ_HANDLED;
  61         rmb();                  /* ensure we see ring contents up to prod */
  62         for (cons = page->in_cons; cons != prod; cons++) {
  63                 union xenkbd_in_event *event;
  64                 struct input_dev *dev;
  65                 event = &XENKBD_IN_RING_REF(page, cons);
  66
  67                 dev = info->ptr;
  68                 switch (event->type) {
  69                 case XENKBD_TYPE_MOTION:
  70                         input_report_rel(dev, REL_X, event->motion.rel_x);
  71                         input_report_rel(dev, REL_Y, event->motion.rel_y);
  72                         if (event->motion.rel_z)
  73                                 input_report_rel(dev, REL_WHEEL,
  74                                                  -event->motion.rel_z);
  75                         break;
  76                 case XENKBD_TYPE_KEY:
  77                         dev = NULL;
  78                         if (test_bit(event->key.keycode, info->kbd->keybit))
  79                                 dev = info->kbd;
  80                         if (test_bit(event->key.keycode, info->ptr->keybit))
  81                                 dev = info->ptr;
  82                         if (dev)
  83                                 input_report_key(dev, event->key.keycode,
  84                                                  event->key.pressed);
  85                         else
  86                                 printk(KERN_WARNING
  87                                        "xenkbd: unhandled keycode 0x%x\n",
  88                                        event->key.keycode);
  89                         break;
  90                 case XENKBD_TYPE_POS:
  91                         input_report_abs(dev, ABS_X, event->pos.abs_x);
  92                         input_report_abs(dev, ABS_Y, event->pos.abs_y);
  93                         if (event->pos.rel_z)
  94                                 input_report_rel(dev, REL_WHEEL,
  95                                                  -event->pos.rel_z);
  96                         break;
  97                 }
  98                 if (dev)
  99                         input_sync(dev);
 100         }
 101         mb();                   /* ensure we got ring contents */
 102         page->in_cons = cons;
 103         notify_remote_via_irq(info->irq);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 static int __devinit xenkbd_probe(struct xenbus_device *dev,
 109                                   const struct xenbus_device_id *id)
 110 {
 111         int ret, i, abs;
 112         struct xenkbd_info *info;
 113         struct input_dev *kbd, *ptr;
 114
 115         info = kzalloc(sizeof(*info), GFP_KERNEL);
 116         if (!info) {
 117                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
 118                 return -ENOMEM;
 119         }
 120         dev_set_drvdata(&dev->dev, info);
 121         info->xbdev = dev;
 122         info->irq = -1;
 123         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
 124
 125         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 126         if (!info->page)
 127                 goto error_nomem;
 128
 129         if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
 130                 abs = 0;
 131         if (abs)
 132                 xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
 133
 134         /* keyboard */
 135         kbd = input_allocate_device();
 136         if (!kbd)
 137                 goto error_nomem;
 138         kbd->name = "Xen Virtual Keyboard";
 139         kbd->phys = info->phys;
 140         kbd->id.bustype = BUS_PCI;
 141         kbd->id.vendor = 0x5853;
 142         kbd->id.product = 0xffff;
 143
 144         __set_bit(EV_KEY, kbd->evbit);
 145         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 146                 __set_bit(i, kbd->keybit);
 147         for (i = KEY_OK; i < KEY_MAX; i++)
 148                 __set_bit(i, kbd->keybit);
 149
 150         ret = input_register_device(kbd);
 151         if (ret) {
 152                 input_free_device(kbd);
 153                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 154                 goto error;
 155         }
 156         info->kbd = kbd;
 157
 158         /* pointing device */
 159         ptr = input_allocate_device();
 160         if (!ptr)
 161                 goto error_nomem;
 162         ptr->name = "Xen Virtual Pointer";
 163         ptr->phys = info->phys;
 164         ptr->id.bustype = BUS_PCI;
 165         ptr->id.vendor = 0x5853;
 166         ptr->id.product = 0xfffe;
 167
 168         if (abs) {
 169                 __set_bit(EV_ABS, ptr->evbit);
 170                 input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
 171                 input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
 172         } else {
 173                 input_set_capability(ptr, EV_REL, REL_X);
 174                 input_set_capability(ptr, EV_REL, REL_Y);
 175         }
 176         input_set_capability(ptr, EV_REL, REL_WHEEL);
 177
 178         __set_bit(EV_KEY, ptr->evbit);
 179         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 180                 __set_bit(i, ptr->keybit);
 181
 182         ret = input_register_device(ptr);
 183         if (ret) {
 184                 input_free_device(ptr);
 185                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 186                 goto error;
 187         }
 188         info->ptr = ptr;
 189
 190         ret = xenkbd_connect_backend(dev, info);
 191         if (ret < 0)
 192                 goto error;
 193
 194         return 0;
 195
 196  error_nomem:
 197         ret = -ENOMEM;
 198         xenbus_dev_fatal(dev, ret, "allocating device memory");
 199  error:
 200         xenkbd_remove(dev);
 201         return ret;
 202 }
 203
 204 static int xenkbd_resume(struct xenbus_device *dev)
 205 {
 206         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 207
 208         xenkbd_disconnect_backend(info);
 209         memset(info->page, 0, PAGE_SIZE);
 210         return xenkbd_connect_backend(dev, info);
 211 }
 212
 213 static int xenkbd_remove(struct xenbus_device *dev)
 214 {
 215         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 216
 217         xenkbd_disconnect_backend(info);
 218         if (info->kbd)
 219                 input_unregister_device(info->kbd);
 220         if (info->ptr)
 221                 input_unregister_device(info->ptr);
 222         free_page((unsigned long)info->page);
 223         kfree(info);
 224         return 0;
 225 }
 226
 227 static int xenkbd_connect_backend(struct xenbus_device *dev,
 228                                   struct xenkbd_info *info)
 229 {
 230         int ret, evtchn;
 231         struct xenbus_transaction xbt;
 232
 233         ret = xenbus_alloc_evtchn(dev, &evtchn);
 234         if (ret)
 235                 return ret;
 236         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 237                                         0, dev->devicetype, info);
 238         if (ret < 0) {
 239                 xenbus_free_evtchn(dev, evtchn);
 240                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 241                 return ret;
 242         }
 243         info->irq = ret;
 244
 245  again:
 246         ret = xenbus_transaction_start(&xbt);
 247         if (ret) {
 248                 xenbus_dev_fatal(dev, ret, "starting transaction");
 249                 return ret;
 250         }
 251         ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
 252                             virt_to_mfn(info->page));
 253         if (ret)
 254                 goto error_xenbus;
 255         ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
 256                             evtchn);
 257         if (ret)
 258                 goto error_xenbus;
 259         ret = xenbus_transaction_end(xbt, 0);
 260         if (ret) {
 261                 if (ret == -EAGAIN)
 262                         goto again;
 263                 xenbus_dev_fatal(dev, ret, "completing transaction");
 264                 return ret;
 265         }
 266
 267         xenbus_switch_state(dev, XenbusStateInitialised);
 268         return 0;
 269
 270  error_xenbus:
 271         xenbus_transaction_end(xbt, 1);
 272         xenbus_dev_fatal(dev, ret, "writing xenstore");
 273         return ret;
 274 }
 275
 276 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 277 {
 278         if (info->irq >= 0)
 279                 unbind_from_irqhandler(info->irq, info);
 280         info->irq = -1;
 281 }
 282
 283 static void xenkbd_backend_changed(struct xenbus_device *dev,
 284                                    enum xenbus_state backend_state)
 285 {
 286         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 287         int ret, val;
 288
 289         switch (backend_state) {
 290         case XenbusStateInitialising:
 291         case XenbusStateInitialised:
 292         case XenbusStateUnknown:
 293         case XenbusStateClosed:
 294                 break;
 295
 296         case XenbusStateInitWait:
 297 InitWait:
 298                 ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 299                                    "feature-abs-pointer", "%d", &val);
 300                 if (ret < 0)
 301                         val = 0;
 302                 if (val) {
 303                         ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
 304                                             "request-abs-pointer", "1");
 305                         if (ret)
 306                                 pr_warning("can't request abs-pointer\n");
 307                 }
 308                 xenbus_switch_state(dev, XenbusStateConnected);
 309                 break;
 310
 311         case XenbusStateConnected:
 312                 /*
 313                  * Work around xenbus race condition: If backend goes
 314                  * through InitWait to Connected fast enough, we can
 315                  * get Connected twice here.
 316                  */
 317                 if (dev->state != XenbusStateConnected)
 318                         goto InitWait; /* no InitWait seen yet, fudge it */
 319
 320                 /* Set input abs params to match backend screen res */
 321                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 322                                  "width", "%d", &val) > 0)
 323                         input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
 324
 325                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 326                                  "height", "%d", &val) > 0)
 327                         input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
 328
 329                 break;
 330
 331         case XenbusStateClosing:
 332                 xenbus_frontend_closed(dev);
 333                 break;
 334         }
 335 }
 336
 337 static struct xenbus_device_id xenkbd_ids[] = {
 338         { "vkbd" },
 339         { "" }
 340 };
 341
 342 static struct xenbus_driver xenkbd_driver = {
 343         .name = "vkbd",
 344         .owner = THIS_MODULE,
 345         .ids = xenkbd_ids,
 346         .probe = xenkbd_probe,
 347         .remove = xenkbd_remove,
 348         .resume = xenkbd_resume,
 349         .otherend_changed = xenkbd_backend_changed,
 350 };
 351
 352 static int __init xenkbd_init(void)
 353 {
 354         if (!xen_domain())
 355                 return -ENODEV;
 356
 357         /* Nothing to do if running in dom0. */
 358         if (xen_initial_domain())
 359                 return -ENODEV;
 360
 361         return xenbus_register_frontend(&xenkbd_driver);
 362 }
 363
 364 static void __exit xenkbd_cleanup(void)
 365 {
 366         xenbus_unregister_driver(&xenkbd_driver);
 367 }
 368
 369 module_init(xenkbd_init);
 370 module_exit(xenkbd_cleanup);
 371
 372 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 373 MODULE_LICENSE("GPL");
 374 MODULE_ALIAS("xen:vkbd");