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