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;
 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         /* keyboard */
 127         kbd = input_allocate_device();
 128         if (!kbd)
 129                 goto error_nomem;
 130         kbd->name = "Xen Virtual Keyboard";
 131         kbd->phys = info->phys;
 132         kbd->id.bustype = BUS_PCI;
 133         kbd->id.vendor = 0x5853;
 134         kbd->id.product = 0xffff;
 135         kbd->evbit[0] = BIT(EV_KEY);
 136         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
 137                 set_bit(i, kbd->keybit);
 138         for (i = KEY_OK; i < KEY_MAX; i++)
 139                 set_bit(i, kbd->keybit);
 140
 141         ret = input_register_device(kbd);
 142         if (ret) {
 143                 input_free_device(kbd);
 144                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
 145                 goto error;
 146         }
 147         info->kbd = kbd;
 148
 149         /* pointing device */
 150         ptr = input_allocate_device();
 151         if (!ptr)
 152                 goto error_nomem;
 153         ptr->name = "Xen Virtual Pointer";
 154         ptr->phys = info->phys;
 155         ptr->id.bustype = BUS_PCI;
 156         ptr->id.vendor = 0x5853;
 157         ptr->id.product = 0xfffe;
 158         ptr->evbit[0] = BIT(EV_KEY) | BIT(EV_REL) | BIT(EV_ABS);
 159         for (i = BTN_LEFT; i <= BTN_TASK; i++)
 160                 set_bit(i, ptr->keybit);
 161         ptr->relbit[0] = BIT(REL_X) | BIT(REL_Y) | BIT(REL_WHEEL);
 162         input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
 163         input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
 164
 165         ret = input_register_device(ptr);
 166         if (ret) {
 167                 input_free_device(ptr);
 168                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
 169                 goto error;
 170         }
 171         info->ptr = ptr;
 172
 173         ret = xenkbd_connect_backend(dev, info);
 174         if (ret < 0)
 175                 goto error;
 176
 177         return 0;
 178
 179  error_nomem:
 180         ret = -ENOMEM;
 181         xenbus_dev_fatal(dev, ret, "allocating device memory");
 182  error:
 183         xenkbd_remove(dev);
 184         return ret;
 185 }
 186
 187 static int xenkbd_resume(struct xenbus_device *dev)
 188 {
 189         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 190
 191         xenkbd_disconnect_backend(info);
 192         memset(info->page, 0, PAGE_SIZE);
 193         return xenkbd_connect_backend(dev, info);
 194 }
 195
 196 static int xenkbd_remove(struct xenbus_device *dev)
 197 {
 198         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 199
 200         xenkbd_disconnect_backend(info);
 201         if (info->kbd)
 202                 input_unregister_device(info->kbd);
 203         if (info->ptr)
 204                 input_unregister_device(info->ptr);
 205         free_page((unsigned long)info->page);
 206         kfree(info);
 207         return 0;
 208 }
 209
 210 static int xenkbd_connect_backend(struct xenbus_device *dev,
 211                                   struct xenkbd_info *info)
 212 {
 213         int ret, evtchn;
 214         struct xenbus_transaction xbt;
 215
 216         ret = xenbus_alloc_evtchn(dev, &evtchn);
 217         if (ret)
 218                 return ret;
 219         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
 220                                         0, dev->devicetype, info);
 221         if (ret < 0) {
 222                 xenbus_free_evtchn(dev, evtchn);
 223                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
 224                 return ret;
 225         }
 226         info->irq = ret;
 227
 228  again:
 229         ret = xenbus_transaction_start(&xbt);
 230         if (ret) {
 231                 xenbus_dev_fatal(dev, ret, "starting transaction");
 232                 return ret;
 233         }
 234         ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
 235                             virt_to_mfn(info->page));
 236         if (ret)
 237                 goto error_xenbus;
 238         ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
 239                             evtchn);
 240         if (ret)
 241                 goto error_xenbus;
 242         ret = xenbus_transaction_end(xbt, 0);
 243         if (ret) {
 244                 if (ret == -EAGAIN)
 245                         goto again;
 246                 xenbus_dev_fatal(dev, ret, "completing transaction");
 247                 return ret;
 248         }
 249
 250         xenbus_switch_state(dev, XenbusStateInitialised);
 251         return 0;
 252
 253  error_xenbus:
 254         xenbus_transaction_end(xbt, 1);
 255         xenbus_dev_fatal(dev, ret, "writing xenstore");
 256         return ret;
 257 }
 258
 259 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
 260 {
 261         if (info->irq >= 0)
 262                 unbind_from_irqhandler(info->irq, info);
 263         info->irq = -1;
 264 }
 265
 266 static void xenkbd_backend_changed(struct xenbus_device *dev,
 267                                    enum xenbus_state backend_state)
 268 {
 269         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
 270         int ret, val;
 271
 272         switch (backend_state) {
 273         case XenbusStateInitialising:
 274         case XenbusStateInitialised:
 275         case XenbusStateUnknown:
 276         case XenbusStateClosed:
 277                 break;
 278
 279         case XenbusStateInitWait:
 280 InitWait:
 281                 ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 282                                    "feature-abs-pointer", "%d", &val);
 283                 if (ret < 0)
 284                         val = 0;
 285                 if (val) {
 286                         ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
 287                                             "request-abs-pointer", "1");
 288                         if (ret)
 289                                 printk(KERN_WARNING
 290                                        "xenkbd: can't request abs-pointer");
 291                 }
 292                 xenbus_switch_state(dev, XenbusStateConnected);
 293                 break;
 294
 295         case XenbusStateConnected:
 296                 /*
 297                  * Work around xenbus race condition: If backend goes
 298                  * through InitWait to Connected fast enough, we can
 299                  * get Connected twice here.
 300                  */
 301                 if (dev->state != XenbusStateConnected)
 302                         goto InitWait; /* no InitWait seen yet, fudge it */
 303
 304                 /* Set input abs params to match backend screen res */
 305                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 306                                  "width", "%d", &val) > 0)
 307                         input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);
 308
 309                 if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
 310                                  "height", "%d", &val) > 0)
 311                         input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);
 312
 313                 break;
 314
 315         case XenbusStateClosing:
 316                 xenbus_frontend_closed(dev);
 317                 break;
 318         }
 319 }
 320
 321 static struct xenbus_device_id xenkbd_ids[] = {
 322         { "vkbd" },
 323         { "" }
 324 };
 325
 326 static struct xenbus_driver xenkbd_driver = {
 327         .name = "vkbd",
 328         .owner = THIS_MODULE,
 329         .ids = xenkbd_ids,
 330         .probe = xenkbd_probe,
 331         .remove = xenkbd_remove,
 332         .resume = xenkbd_resume,
 333         .otherend_changed = xenkbd_backend_changed,
 334 };
 335
 336 static int __init xenkbd_init(void)
 337 {
 338         if (!xen_domain())
 339                 return -ENODEV;
 340
 341         /* Nothing to do if running in dom0. */
 342         if (xen_initial_domain())
 343                 return -ENODEV;
 344
 345         return xenbus_register_frontend(&xenkbd_driver);
 346 }
 347
 348 static void __exit xenkbd_cleanup(void)
 349 {
 350         xenbus_unregister_driver(&xenkbd_driver);
 351 }
 352
 353 module_init(xenkbd_init);
 354 module_exit(xenkbd_cleanup);
 355
 356 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
 357 MODULE_LICENSE("GPL");
 358 MODULE_ALIAS("xen:vkbd");