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