GNU Linux-libre 4.14.266-gnu1
[releases.git] / drivers / input / misc / 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/module.h>
19 #include <linux/input.h>
20 #include <linux/input/mt.h>
21 #include <linux/slab.h>
22
23 #include <asm/xen/hypervisor.h>
24
25 #include <xen/xen.h>
26 #include <xen/events.h>
27 #include <xen/page.h>
28 #include <xen/grant_table.h>
29 #include <xen/interface/grant_table.h>
30 #include <xen/interface/io/fbif.h>
31 #include <xen/interface/io/kbdif.h>
32 #include <xen/xenbus.h>
33 #include <xen/platform_pci.h>
34
35 struct xenkbd_info {
36         struct input_dev *kbd;
37         struct input_dev *ptr;
38         struct input_dev *mtouch;
39         struct xenkbd_page *page;
40         int gref;
41         int irq;
42         struct xenbus_device *xbdev;
43         char phys[32];
44         /* current MT slot/contact ID we are injecting events in */
45         int mtouch_cur_contact_id;
46 };
47
48 enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
49 static int ptr_size[KPARAM_CNT] = { XENFB_WIDTH, XENFB_HEIGHT };
50 module_param_array(ptr_size, int, NULL, 0444);
51 MODULE_PARM_DESC(ptr_size,
52         "Pointing device width, height in pixels (default 800,600)");
53
54 static int xenkbd_remove(struct xenbus_device *);
55 static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
56 static void xenkbd_disconnect_backend(struct xenkbd_info *);
57
58 /*
59  * Note: if you need to send out events, see xenfb_do_update() for how
60  * to do that.
61  */
62
63 static void xenkbd_handle_motion_event(struct xenkbd_info *info,
64                                        struct xenkbd_motion *motion)
65 {
66         input_report_rel(info->ptr, REL_X, motion->rel_x);
67         input_report_rel(info->ptr, REL_Y, motion->rel_y);
68         if (motion->rel_z)
69                 input_report_rel(info->ptr, REL_WHEEL, -motion->rel_z);
70         input_sync(info->ptr);
71 }
72
73 static void xenkbd_handle_position_event(struct xenkbd_info *info,
74                                          struct xenkbd_position *pos)
75 {
76         input_report_abs(info->ptr, ABS_X, pos->abs_x);
77         input_report_abs(info->ptr, ABS_Y, pos->abs_y);
78         if (pos->rel_z)
79                 input_report_rel(info->ptr, REL_WHEEL, -pos->rel_z);
80         input_sync(info->ptr);
81 }
82
83 static void xenkbd_handle_key_event(struct xenkbd_info *info,
84                                     struct xenkbd_key *key)
85 {
86         struct input_dev *dev;
87         int value = key->pressed;
88
89         if (test_bit(key->keycode, info->ptr->keybit)) {
90                 dev = info->ptr;
91         } else if (test_bit(key->keycode, info->kbd->keybit)) {
92                 dev = info->kbd;
93                 if (key->pressed && test_bit(key->keycode, info->kbd->key))
94                         value = 2; /* Mark as autorepeat */
95         } else {
96                 pr_warn("unhandled keycode 0x%x\n", key->keycode);
97                 return;
98         }
99
100         input_event(dev, EV_KEY, key->keycode, value);
101         input_sync(dev);
102 }
103
104 static void xenkbd_handle_mt_event(struct xenkbd_info *info,
105                                    struct xenkbd_mtouch *mtouch)
106 {
107         if (unlikely(!info->mtouch))
108                 return;
109
110         if (mtouch->contact_id != info->mtouch_cur_contact_id) {
111                 info->mtouch_cur_contact_id = mtouch->contact_id;
112                 input_mt_slot(info->mtouch, mtouch->contact_id);
113         }
114
115         switch (mtouch->event_type) {
116         case XENKBD_MT_EV_DOWN:
117                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, true);
118                 /* fall through */
119
120         case XENKBD_MT_EV_MOTION:
121                 input_report_abs(info->mtouch, ABS_MT_POSITION_X,
122                                  mtouch->u.pos.abs_x);
123                 input_report_abs(info->mtouch, ABS_MT_POSITION_Y,
124                                  mtouch->u.pos.abs_y);
125                 break;
126
127         case XENKBD_MT_EV_SHAPE:
128                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MAJOR,
129                                  mtouch->u.shape.major);
130                 input_report_abs(info->mtouch, ABS_MT_TOUCH_MINOR,
131                                  mtouch->u.shape.minor);
132                 break;
133
134         case XENKBD_MT_EV_ORIENT:
135                 input_report_abs(info->mtouch, ABS_MT_ORIENTATION,
136                                  mtouch->u.orientation);
137                 break;
138
139         case XENKBD_MT_EV_UP:
140                 input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, false);
141                 break;
142
143         case XENKBD_MT_EV_SYN:
144                 input_mt_sync_frame(info->mtouch);
145                 input_sync(info->mtouch);
146                 break;
147         }
148 }
149
150 static void xenkbd_handle_event(struct xenkbd_info *info,
151                                 union xenkbd_in_event *event)
152 {
153         switch (event->type) {
154         case XENKBD_TYPE_MOTION:
155                 xenkbd_handle_motion_event(info, &event->motion);
156                 break;
157
158         case XENKBD_TYPE_KEY:
159                 xenkbd_handle_key_event(info, &event->key);
160                 break;
161
162         case XENKBD_TYPE_POS:
163                 xenkbd_handle_position_event(info, &event->pos);
164                 break;
165
166         case XENKBD_TYPE_MTOUCH:
167                 xenkbd_handle_mt_event(info, &event->mtouch);
168                 break;
169         }
170 }
171
172 static irqreturn_t input_handler(int rq, void *dev_id)
173 {
174         struct xenkbd_info *info = dev_id;
175         struct xenkbd_page *page = info->page;
176         __u32 cons, prod;
177
178         prod = page->in_prod;
179         if (prod == page->in_cons)
180                 return IRQ_HANDLED;
181         rmb();                  /* ensure we see ring contents up to prod */
182         for (cons = page->in_cons; cons != prod; cons++)
183                 xenkbd_handle_event(info, &XENKBD_IN_RING_REF(page, cons));
184         mb();                   /* ensure we got ring contents */
185         page->in_cons = cons;
186         notify_remote_via_irq(info->irq);
187
188         return IRQ_HANDLED;
189 }
190
191 static int xenkbd_probe(struct xenbus_device *dev,
192                                   const struct xenbus_device_id *id)
193 {
194         int ret, i;
195         unsigned int abs, touch;
196         struct xenkbd_info *info;
197         struct input_dev *kbd, *ptr, *mtouch;
198
199         info = kzalloc(sizeof(*info), GFP_KERNEL);
200         if (!info) {
201                 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
202                 return -ENOMEM;
203         }
204         dev_set_drvdata(&dev->dev, info);
205         info->xbdev = dev;
206         info->irq = -1;
207         info->gref = -1;
208         snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
209
210         info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
211         if (!info->page)
212                 goto error_nomem;
213
214         /* Set input abs params to match backend screen res */
215         abs = xenbus_read_unsigned(dev->otherend,
216                                    XENKBD_FIELD_FEAT_ABS_POINTER, 0);
217         ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend,
218                                                   XENKBD_FIELD_WIDTH,
219                                                   ptr_size[KPARAM_X]);
220         ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend,
221                                                   XENKBD_FIELD_HEIGHT,
222                                                   ptr_size[KPARAM_Y]);
223         if (abs) {
224                 ret = xenbus_write(XBT_NIL, dev->nodename,
225                                    XENKBD_FIELD_REQ_ABS_POINTER, "1");
226                 if (ret) {
227                         pr_warn("xenkbd: can't request abs-pointer\n");
228                         abs = 0;
229                 }
230         }
231
232         touch = xenbus_read_unsigned(dev->otherend,
233                                      XENKBD_FIELD_FEAT_MTOUCH, 0);
234         if (touch) {
235                 ret = xenbus_write(XBT_NIL, dev->nodename,
236                                    XENKBD_FIELD_REQ_MTOUCH, "1");
237                 if (ret) {
238                         pr_warn("xenkbd: can't request multi-touch");
239                         touch = 0;
240                 }
241         }
242
243         /* keyboard */
244         kbd = input_allocate_device();
245         if (!kbd)
246                 goto error_nomem;
247         kbd->name = "Xen Virtual Keyboard";
248         kbd->phys = info->phys;
249         kbd->id.bustype = BUS_PCI;
250         kbd->id.vendor = 0x5853;
251         kbd->id.product = 0xffff;
252
253         __set_bit(EV_KEY, kbd->evbit);
254         for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
255                 __set_bit(i, kbd->keybit);
256         for (i = KEY_OK; i < KEY_MAX; i++)
257                 __set_bit(i, kbd->keybit);
258
259         ret = input_register_device(kbd);
260         if (ret) {
261                 input_free_device(kbd);
262                 xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
263                 goto error;
264         }
265         info->kbd = kbd;
266
267         /* pointing device */
268         ptr = input_allocate_device();
269         if (!ptr)
270                 goto error_nomem;
271         ptr->name = "Xen Virtual Pointer";
272         ptr->phys = info->phys;
273         ptr->id.bustype = BUS_PCI;
274         ptr->id.vendor = 0x5853;
275         ptr->id.product = 0xfffe;
276
277         if (abs) {
278                 __set_bit(EV_ABS, ptr->evbit);
279                 input_set_abs_params(ptr, ABS_X, 0, ptr_size[KPARAM_X], 0, 0);
280                 input_set_abs_params(ptr, ABS_Y, 0, ptr_size[KPARAM_Y], 0, 0);
281         } else {
282                 input_set_capability(ptr, EV_REL, REL_X);
283                 input_set_capability(ptr, EV_REL, REL_Y);
284         }
285         input_set_capability(ptr, EV_REL, REL_WHEEL);
286
287         __set_bit(EV_KEY, ptr->evbit);
288         for (i = BTN_LEFT; i <= BTN_TASK; i++)
289                 __set_bit(i, ptr->keybit);
290
291         ret = input_register_device(ptr);
292         if (ret) {
293                 input_free_device(ptr);
294                 xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
295                 goto error;
296         }
297         info->ptr = ptr;
298
299         /* multi-touch device */
300         if (touch) {
301                 int num_cont, width, height;
302
303                 mtouch = input_allocate_device();
304                 if (!mtouch)
305                         goto error_nomem;
306
307                 num_cont = xenbus_read_unsigned(info->xbdev->otherend,
308                                                 XENKBD_FIELD_MT_NUM_CONTACTS,
309                                                 1);
310                 width = xenbus_read_unsigned(info->xbdev->otherend,
311                                              XENKBD_FIELD_MT_WIDTH,
312                                              XENFB_WIDTH);
313                 height = xenbus_read_unsigned(info->xbdev->otherend,
314                                               XENKBD_FIELD_MT_HEIGHT,
315                                               XENFB_HEIGHT);
316
317                 mtouch->name = "Xen Virtual Multi-touch";
318                 mtouch->phys = info->phys;
319                 mtouch->id.bustype = BUS_PCI;
320                 mtouch->id.vendor = 0x5853;
321                 mtouch->id.product = 0xfffd;
322
323                 input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
324                                      0, 255, 0, 0);
325                 input_set_abs_params(mtouch, ABS_MT_POSITION_X,
326                                      0, width, 0, 0);
327                 input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
328                                      0, height, 0, 0);
329
330                 ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
331                 if (ret) {
332                         input_free_device(mtouch);
333                         xenbus_dev_fatal(info->xbdev, ret,
334                                          "input_mt_init_slots");
335                         goto error;
336                 }
337
338                 ret = input_register_device(mtouch);
339                 if (ret) {
340                         input_free_device(mtouch);
341                         xenbus_dev_fatal(info->xbdev, ret,
342                                          "input_register_device(mtouch)");
343                         goto error;
344                 }
345                 info->mtouch_cur_contact_id = -1;
346                 info->mtouch = mtouch;
347         }
348
349         ret = xenkbd_connect_backend(dev, info);
350         if (ret < 0)
351                 goto error;
352
353         return 0;
354
355  error_nomem:
356         ret = -ENOMEM;
357         xenbus_dev_fatal(dev, ret, "allocating device memory");
358  error:
359         xenkbd_remove(dev);
360         return ret;
361 }
362
363 static int xenkbd_resume(struct xenbus_device *dev)
364 {
365         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
366
367         xenkbd_disconnect_backend(info);
368         memset(info->page, 0, PAGE_SIZE);
369         return xenkbd_connect_backend(dev, info);
370 }
371
372 static int xenkbd_remove(struct xenbus_device *dev)
373 {
374         struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
375
376         xenkbd_disconnect_backend(info);
377         if (info->kbd)
378                 input_unregister_device(info->kbd);
379         if (info->ptr)
380                 input_unregister_device(info->ptr);
381         if (info->mtouch)
382                 input_unregister_device(info->mtouch);
383         free_page((unsigned long)info->page);
384         kfree(info);
385         return 0;
386 }
387
388 static int xenkbd_connect_backend(struct xenbus_device *dev,
389                                   struct xenkbd_info *info)
390 {
391         int ret, evtchn;
392         struct xenbus_transaction xbt;
393
394         ret = gnttab_grant_foreign_access(dev->otherend_id,
395                                           virt_to_gfn(info->page), 0);
396         if (ret < 0)
397                 return ret;
398         info->gref = ret;
399
400         ret = xenbus_alloc_evtchn(dev, &evtchn);
401         if (ret)
402                 goto error_grant;
403         ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
404                                         0, dev->devicetype, info);
405         if (ret < 0) {
406                 xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
407                 goto error_evtchan;
408         }
409         info->irq = ret;
410
411  again:
412         ret = xenbus_transaction_start(&xbt);
413         if (ret) {
414                 xenbus_dev_fatal(dev, ret, "starting transaction");
415                 goto error_irqh;
416         }
417         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_REF, "%lu",
418                             virt_to_gfn(info->page));
419         if (ret)
420                 goto error_xenbus;
421         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_GREF,
422                             "%u", info->gref);
423         if (ret)
424                 goto error_xenbus;
425         ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_EVT_CHANNEL, "%u",
426                             evtchn);
427         if (ret)
428                 goto error_xenbus;
429         ret = xenbus_transaction_end(xbt, 0);
430         if (ret) {
431                 if (ret == -EAGAIN)
432                         goto again;
433                 xenbus_dev_fatal(dev, ret, "completing transaction");
434                 goto error_irqh;
435         }
436
437         xenbus_switch_state(dev, XenbusStateInitialised);
438         return 0;
439
440  error_xenbus:
441         xenbus_transaction_end(xbt, 1);
442         xenbus_dev_fatal(dev, ret, "writing xenstore");
443  error_irqh:
444         unbind_from_irqhandler(info->irq, info);
445         info->irq = -1;
446  error_evtchan:
447         xenbus_free_evtchn(dev, evtchn);
448  error_grant:
449         gnttab_end_foreign_access(info->gref, 0, 0UL);
450         info->gref = -1;
451         return ret;
452 }
453
454 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
455 {
456         if (info->irq >= 0)
457                 unbind_from_irqhandler(info->irq, info);
458         info->irq = -1;
459         if (info->gref >= 0)
460                 gnttab_end_foreign_access(info->gref, 0, 0UL);
461         info->gref = -1;
462 }
463
464 static void xenkbd_backend_changed(struct xenbus_device *dev,
465                                    enum xenbus_state backend_state)
466 {
467         switch (backend_state) {
468         case XenbusStateInitialising:
469         case XenbusStateInitialised:
470         case XenbusStateReconfiguring:
471         case XenbusStateReconfigured:
472         case XenbusStateUnknown:
473                 break;
474
475         case XenbusStateInitWait:
476                 xenbus_switch_state(dev, XenbusStateConnected);
477                 break;
478
479         case XenbusStateConnected:
480                 /*
481                  * Work around xenbus race condition: If backend goes
482                  * through InitWait to Connected fast enough, we can
483                  * get Connected twice here.
484                  */
485                 if (dev->state != XenbusStateConnected)
486                         xenbus_switch_state(dev, XenbusStateConnected);
487                 break;
488
489         case XenbusStateClosed:
490                 if (dev->state == XenbusStateClosed)
491                         break;
492                 /* Missed the backend's CLOSING state -- fallthrough */
493         case XenbusStateClosing:
494                 xenbus_frontend_closed(dev);
495                 break;
496         }
497 }
498
499 static const struct xenbus_device_id xenkbd_ids[] = {
500         { XENKBD_DRIVER_NAME },
501         { "" }
502 };
503
504 static struct xenbus_driver xenkbd_driver = {
505         .ids = xenkbd_ids,
506         .probe = xenkbd_probe,
507         .remove = xenkbd_remove,
508         .resume = xenkbd_resume,
509         .otherend_changed = xenkbd_backend_changed,
510 };
511
512 static int __init xenkbd_init(void)
513 {
514         if (!xen_domain())
515                 return -ENODEV;
516
517         /* Nothing to do if running in dom0. */
518         if (xen_initial_domain())
519                 return -ENODEV;
520
521         if (!xen_has_pv_devices())
522                 return -ENODEV;
523
524         return xenbus_register_frontend(&xenkbd_driver);
525 }
526
527 static void __exit xenkbd_cleanup(void)
528 {
529         xenbus_unregister_driver(&xenkbd_driver);
530 }
531
532 module_init(xenkbd_init);
533 module_exit(xenkbd_cleanup);
534
535 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
536 MODULE_LICENSE("GPL");
537 MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);