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;
 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         /* 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         kbd->evbit[0] = BIT(EV_KEY);
 141         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 142                 set_bit(i, kbd->keybit);
 143         for (i = KEY_OK; i < KEY_MAX; i++)
 144                 set_bit(i, kbd->keybit);
 145
 146         ret = input_register_device(kbd);
 147         if (ret) {
 148                 input_free_device(kbd);
 149                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 150                 goto error;
 151         }
 152         info->kbd = kbd;
 153
 154         /* pointing device */
 155         ptr = input_allocate_device();
 156         if (!ptr)
 157                 goto error_nomem;
 158         ptr->name = "Xen Virtual Pointer";
 159         ptr->phys = info->phys;
 160         ptr->id.bustype = BUS_PCI;
 161         ptr->id.vendor = 0x5853;
 162         ptr->id.product = 0xfffe;
 163         ptr->evbit[0] = BIT(EV_KEY) | BIT(EV_REL) | BIT(EV_ABS);
 164         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 165                 set_bit(i, ptr->keybit);
 166         ptr->relbit[0] = BIT(REL_X) | BIT(REL_Y) | BIT(REL_WHEEL);
 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
 170         ret = input_register_device(ptr);
 171         if (ret) {
 172                 input_free_device(ptr);
 173                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 174                 goto error;
 175         }
 176         info->ptr = ptr;
 177
 178         ret = xenkbd_connect_backend(dev, info);
 179         if (ret < 0)
 180                 goto error;
 181
 182         return 0;
 183
 184  error_nomem:
 185         ret = -ENOMEM;
 186         xenbus_dev_fatal(dev, ret, "allocating device memory");
 187  error:
 188         xenkbd_remove(dev);
 189         return ret;
 190 }
 191
 192 static int xenkbd_resume(struct xenbus_device *dev)
 193 {
 194         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 195
 196         xenkbd_disconnect_backend(info);
 197         memset(info->page, 0, PAGE_SIZE);
 198         return xenkbd_connect_backend(dev, info);
 199 }
 200
 201 static int xenkbd_remove(struct xenbus_device *dev)
 202 {
 203         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 204
 205         xenkbd_disconnect_backend(info);
 206         if (info->kbd)
 207                 input_unregister_device(info->kbd);
 208         if (info->ptr)
 209                 input_unregister_device(info->ptr);
 210         free_page((unsigned long)info->page);
 211         kfree(info);
 212         return 0;
 213 }
 214
 215 static int xenkbd_connect_backend(struct xenbus_device *dev,
 216                                   struct xenkbd_info *info)
 217 {
 218         int ret, evtchn;
 219         struct xenbus_transaction xbt;
 220
 221         ret = xenbus_alloc_evtchn(dev, &evtchn);
 222         if (ret)
 223                 return ret;
 224         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 225                                         0, dev->devicetype, info);
 226         if (ret < 0) {
 227                 xenbus_free_evtchn(dev, evtchn);
 228                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 229                 return ret;
 230         }
 231         info->irq = ret;
 232
 233  again:
 234         ret = xenbus_transaction_start(&xbt);
 235         if (ret) {
 236                 xenbus_dev_fatal(dev, ret, "starting transaction");
 237                 return ret;
 238         }
 239         ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
 240                             virt_to_mfn(info->page));
 241         if (ret)
 242                 goto error_xenbus;
 243         ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
 244                             evtchn);
 245         if (ret)
 246                 goto error_xenbus;
 247         ret = xenbus_transaction_end(xbt, 0);
 248         if (ret) {
 249                 if (ret == -EAGAIN)
 250                         goto again;
 251                 xenbus_dev_fatal(dev, ret, "completing transaction");
 252                 return ret;
 253         }
 254
 255         xenbus_switch_state(dev, XenbusStateInitialised);
 256         return 0;
 257
 258  error_xenbus:
 259         xenbus_transaction_end(xbt, 1);
 260         xenbus_dev_fatal(dev, ret, "writing xenstore");
 261         return ret;
 262 }
 263
 264 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 265 {
 266         if (info->irq >= 0)
 267                 unbind_from_irqhandler(info->irq, info);
 268         info->irq = -1;
 269 }
 270
 271 static void xenkbd_backend_changed(struct xenbus_device *dev,
 272                                    enum xenbus_state backend_state)
 273 {
 274         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 275         int ret, val;
 276
 277         switch (backend_state) {
 278         case XenbusStateInitialising:
 279         case XenbusStateInitialised:
 280         case XenbusStateReconfiguring:
 281         case XenbusStateReconfigured:
 282         case XenbusStateUnknown:
 283         case XenbusStateClosed:
 284                 break;
 285
 286         case XenbusStateInitWait:
 287 InitWait:
 288                 ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 289                                    "feature-abs-pointer", "%d", &val);
 290                 if (ret < 0)
 291                         val = 0;
 292                 if (val) {
 293                         ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
 294                                             "request-abs-pointer", "1");
 295                         if (ret)
 296                                 pr_warning("can't request abs-pointer\n");
 297                 }
 298                 xenbus_switch_state(dev, XenbusStateConnected);
 299                 break;
 300
 301         case XenbusStateConnected:
 302                 /*
 303                  * Work around xenbus race condition: If backend goes
 304                  * through InitWait to Connected fast enough, we can
 305                  * get Connected twice here.
 306                  */
 307                 if (dev->state != XenbusStateConnected)
 308                         goto InitWait; /* no InitWait seen yet, fudge it */
 309
 310                 /* Set input abs params to match backend screen res */
 311                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 312                                  "width", "%d", &val) > 0)
 313                         input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
 314
 315                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 316                                  "height", "%d", &val) > 0)
 317                         input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
 318
 319                 break;
 320
 321         case XenbusStateClosing:
 322                 xenbus_frontend_closed(dev);
 323                 break;
 324         }
 325 }
 326
 327 static const struct xenbus_device_id xenkbd_ids[] = {
 328         { "vkbd" },
 329         { "" }
 330 };
 331
 332 static struct xenbus_driver xenkbd_driver = {
 333         .name = "vkbd",
 334         .owner = THIS_MODULE,
 335         .ids = xenkbd_ids,
 336         .probe = xenkbd_probe,
 337         .remove = xenkbd_remove,
 338         .resume = xenkbd_resume,
 339         .otherend_changed = xenkbd_backend_changed,
 340 };
 341
 342 static int __init xenkbd_init(void)
 343 {
 344         if (!xen_pv_domain())
 345                 return -ENODEV;
 346
 347         /* Nothing to do if running in dom0. */
 348         if (xen_initial_domain())
 349                 return -ENODEV;
 350
 351         return xenbus_register_frontend(&xenkbd_driver);
 352 }
 353
 354 static void __exit xenkbd_cleanup(void)
 355 {
 356         xenbus_unregister_driver(&xenkbd_driver);
 357 }
 358
 359 module_init(xenkbd_init);
 360 module_exit(xenkbd_cleanup);
 361
 362 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 363 MODULE_LICENSE("GPL");
 364 MODULE_ALIAS("xen:vkbd");