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->nodename,
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->nodename,
308 						XENKBD_FIELD_MT_NUM_CONTACTS,
309 						1);
310 		width = xenbus_read_unsigned(info->xbdev->nodename,
311 					     XENKBD_FIELD_MT_WIDTH,
312 					     XENFB_WIDTH);
313 		height = xenbus_read_unsigned(info->xbdev->nodename,
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 		input_set_abs_params(mtouch, ABS_MT_PRESSURE,
330 				     0, 255, 0, 0);
331 
332 		ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
333 		if (ret) {
334 			input_free_device(mtouch);
335 			xenbus_dev_fatal(info->xbdev, ret,
336 					 "input_mt_init_slots");
337 			goto error;
338 		}
339 
340 		ret = input_register_device(mtouch);
341 		if (ret) {
342 			input_free_device(mtouch);
343 			xenbus_dev_fatal(info->xbdev, ret,
344 					 "input_register_device(mtouch)");
345 			goto error;
346 		}
347 		info->mtouch_cur_contact_id = -1;
348 		info->mtouch = mtouch;
349 	}
350 
351 	ret = xenkbd_connect_backend(dev, info);
352 	if (ret < 0)
353 		goto error;
354 
355 	return 0;
356 
357  error_nomem:
358 	ret = -ENOMEM;
359 	xenbus_dev_fatal(dev, ret, "allocating device memory");
360  error:
361 	xenkbd_remove(dev);
362 	return ret;
363 }
364 
365 static int xenkbd_resume(struct xenbus_device *dev)
366 {
367 	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
368 
369 	xenkbd_disconnect_backend(info);
370 	memset(info->page, 0, PAGE_SIZE);
371 	return xenkbd_connect_backend(dev, info);
372 }
373 
374 static int xenkbd_remove(struct xenbus_device *dev)
375 {
376 	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
377 
378 	xenkbd_disconnect_backend(info);
379 	if (info->kbd)
380 		input_unregister_device(info->kbd);
381 	if (info->ptr)
382 		input_unregister_device(info->ptr);
383 	if (info->mtouch)
384 		input_unregister_device(info->mtouch);
385 	free_page((unsigned long)info->page);
386 	kfree(info);
387 	return 0;
388 }
389 
390 static int xenkbd_connect_backend(struct xenbus_device *dev,
391 				  struct xenkbd_info *info)
392 {
393 	int ret, evtchn;
394 	struct xenbus_transaction xbt;
395 
396 	ret = gnttab_grant_foreign_access(dev->otherend_id,
397 	                                  virt_to_gfn(info->page), 0);
398 	if (ret < 0)
399 		return ret;
400 	info->gref = ret;
401 
402 	ret = xenbus_alloc_evtchn(dev, &evtchn);
403 	if (ret)
404 		goto error_grant;
405 	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
406 					0, dev->devicetype, info);
407 	if (ret < 0) {
408 		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
409 		goto error_evtchan;
410 	}
411 	info->irq = ret;
412 
413  again:
414 	ret = xenbus_transaction_start(&xbt);
415 	if (ret) {
416 		xenbus_dev_fatal(dev, ret, "starting transaction");
417 		goto error_irqh;
418 	}
419 	ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_REF, "%lu",
420 			    virt_to_gfn(info->page));
421 	if (ret)
422 		goto error_xenbus;
423 	ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_RING_GREF,
424 			    "%u", info->gref);
425 	if (ret)
426 		goto error_xenbus;
427 	ret = xenbus_printf(xbt, dev->nodename, XENKBD_FIELD_EVT_CHANNEL, "%u",
428 			    evtchn);
429 	if (ret)
430 		goto error_xenbus;
431 	ret = xenbus_transaction_end(xbt, 0);
432 	if (ret) {
433 		if (ret == -EAGAIN)
434 			goto again;
435 		xenbus_dev_fatal(dev, ret, "completing transaction");
436 		goto error_irqh;
437 	}
438 
439 	xenbus_switch_state(dev, XenbusStateInitialised);
440 	return 0;
441 
442  error_xenbus:
443 	xenbus_transaction_end(xbt, 1);
444 	xenbus_dev_fatal(dev, ret, "writing xenstore");
445  error_irqh:
446 	unbind_from_irqhandler(info->irq, info);
447 	info->irq = -1;
448  error_evtchan:
449 	xenbus_free_evtchn(dev, evtchn);
450  error_grant:
451 	gnttab_end_foreign_access(info->gref, 0, 0UL);
452 	info->gref = -1;
453 	return ret;
454 }
455 
456 static void xenkbd_disconnect_backend(struct xenkbd_info *info)
457 {
458 	if (info->irq >= 0)
459 		unbind_from_irqhandler(info->irq, info);
460 	info->irq = -1;
461 	if (info->gref >= 0)
462 		gnttab_end_foreign_access(info->gref, 0, 0UL);
463 	info->gref = -1;
464 }
465 
466 static void xenkbd_backend_changed(struct xenbus_device *dev,
467 				   enum xenbus_state backend_state)
468 {
469 	switch (backend_state) {
470 	case XenbusStateInitialising:
471 	case XenbusStateInitialised:
472 	case XenbusStateReconfiguring:
473 	case XenbusStateReconfigured:
474 	case XenbusStateUnknown:
475 		break;
476 
477 	case XenbusStateInitWait:
478 		xenbus_switch_state(dev, XenbusStateConnected);
479 		break;
480 
481 	case XenbusStateConnected:
482 		/*
483 		 * Work around xenbus race condition: If backend goes
484 		 * through InitWait to Connected fast enough, we can
485 		 * get Connected twice here.
486 		 */
487 		if (dev->state != XenbusStateConnected)
488 			xenbus_switch_state(dev, XenbusStateConnected);
489 		break;
490 
491 	case XenbusStateClosed:
492 		if (dev->state == XenbusStateClosed)
493 			break;
494 		/* Missed the backend's CLOSING state -- fallthrough */
495 	case XenbusStateClosing:
496 		xenbus_frontend_closed(dev);
497 		break;
498 	}
499 }
500 
501 static const struct xenbus_device_id xenkbd_ids[] = {
502 	{ XENKBD_DRIVER_NAME },
503 	{ "" }
504 };
505 
506 static struct xenbus_driver xenkbd_driver = {
507 	.ids = xenkbd_ids,
508 	.probe = xenkbd_probe,
509 	.remove = xenkbd_remove,
510 	.resume = xenkbd_resume,
511 	.otherend_changed = xenkbd_backend_changed,
512 };
513 
514 static int __init xenkbd_init(void)
515 {
516 	if (!xen_domain())
517 		return -ENODEV;
518 
519 	/* Nothing to do if running in dom0. */
520 	if (xen_initial_domain())
521 		return -ENODEV;
522 
523 	if (!xen_has_pv_devices())
524 		return -ENODEV;
525 
526 	return xenbus_register_frontend(&xenkbd_driver);
527 }
528 
529 static void __exit xenkbd_cleanup(void)
530 {
531 	xenbus_unregister_driver(&xenkbd_driver);
532 }
533 
534 module_init(xenkbd_init);
535 module_exit(xenkbd_cleanup);
536 
537 MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
538 MODULE_LICENSE("GPL");
539 MODULE_ALIAS("xen:" XENKBD_DRIVER_NAME);
540