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