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