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