summaryrefslogtreecommitdiffstats
path: root/drivers/input/misc/xen-kbdfront.c
blob: 62bae99424e6e436defda3723654816c44be2609 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
/*
 * Xen para-virtual input device
 *
 * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
 * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
 *
 *  Based on linux/drivers/input/mouse/sermouse.c
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/slab.h>

#include <asm/xen/hypervisor.h>

#include <xen/xen.h>
#include <xen/events.h>
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/fbif.h>
#include <xen/interface/io/kbdif.h>
#include <xen/xenbus.h>

struct xenkbd_info {
	struct input_dev *kbd;
	struct input_dev *ptr;
	struct xenkbd_page *page;
	int gref;
	int irq;
	struct xenbus_device *xbdev;
	char phys[32];
};

static int xenkbd_remove(struct xenbus_device *);
static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
static void xenkbd_disconnect_backend(struct xenkbd_info *);

/*
 * Note: if you need to send out events, see xenfb_do_update() for how
 * to do that.
 */

static irqreturn_t input_handler(int rq, void *dev_id)
{
	struct xenkbd_info *info = dev_id;
	struct xenkbd_page *page = info->page;
	__u32 cons, prod;

	prod = page->in_prod;
	if (prod == page->in_cons)
		return IRQ_HANDLED;
	rmb();			/* ensure we see ring contents up to prod */
	for (cons = page->in_cons; cons != prod; cons++) {
		union xenkbd_in_event *event;
		struct input_dev *dev;
		event = &XENKBD_IN_RING_REF(page, cons);

		dev = info->ptr;
		switch (event->type) {
		case XENKBD_TYPE_MOTION:
			input_report_rel(dev, REL_X, event->motion.rel_x);
			input_report_rel(dev, REL_Y, event->motion.rel_y);
			if (event->motion.rel_z)
				input_report_rel(dev, REL_WHEEL,
						 -event->motion.rel_z);
			break;
		case XENKBD_TYPE_KEY:
			dev = NULL;
			if (test_bit(event->key.keycode, info->kbd->keybit))
				dev = info->kbd;
			if (test_bit(event->key.keycode, info->ptr->keybit))
				dev = info->ptr;
			if (dev)
				input_report_key(dev, event->key.keycode,
						 event->key.pressed);
			else
				pr_warning("unhandled keycode 0x%x\n",
					   event->key.keycode);
			break;
		case XENKBD_TYPE_POS:
			input_report_abs(dev, ABS_X, event->pos.abs_x);
			input_report_abs(dev, ABS_Y, event->pos.abs_y);
			if (event->pos.rel_z)
				input_report_rel(dev, REL_WHEEL,
						 -event->pos.rel_z);
			break;
		}
		if (dev)
			input_sync(dev);
	}
	mb();			/* ensure we got ring contents */
	page->in_cons = cons;
	notify_remote_via_irq(info->irq);

	return IRQ_HANDLED;
}

static int __devinit xenkbd_probe(struct xenbus_device *dev,
				  const struct xenbus_device_id *id)
{
	int ret, i, abs;
	struct xenkbd_info *info;
	struct input_dev *kbd, *ptr;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
		return -ENOMEM;
	}
	dev_set_drvdata(&dev->dev, info);
	info->xbdev = dev;
	info->irq = -1;
	info->gref = -1;
	snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);

	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
	if (!info->page)
		goto error_nomem;

	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
		abs = 0;
	if (abs)
		xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");

	/* keyboard */
	kbd = input_allocate_device();
	if (!kbd)
		goto error_nomem;
	kbd->name = "Xen Virtual Keyboard";
	kbd->phys = info->phys;
	kbd->id.bustype = BUS_PCI;
	kbd->id.vendor = 0x5853;
	kbd->id.product = 0xffff;

	__set_bit(EV_KEY, kbd->evbit);
	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
		__set_bit(i, kbd->keybit);
	for (i = KEY_OK; i < KEY_MAX; i++)
		__set_bit(i, kbd->keybit);

	ret = input_register_device(kbd);
	if (ret) {
		input_free_device(kbd);
		xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
		goto error;
	}
	info->kbd = kbd;

	/* pointing device */
	ptr = input_allocate_device();
	if (!ptr)
		goto error_nomem;
	ptr->name = "Xen Virtual Pointer";
	ptr->phys = info->phys;
	ptr->id.bustype = BUS_PCI;
	ptr->id.vendor = 0x5853;
	ptr->id.product = 0xfffe;

	if (abs) {
		__set_bit(EV_ABS, ptr->evbit);
		input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
		input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
	} else {
		input_set_capability(ptr, EV_REL, REL_X);
		input_set_capability(ptr, EV_REL, REL_Y);
	}
	input_set_capability(ptr, EV_REL, REL_WHEEL);

	__set_bit(EV_KEY, ptr->evbit);
	for (i = BTN_LEFT; i <= BTN_TASK; i++)
		__set_bit(i, ptr->keybit);

	ret = input_register_device(ptr);
	if (ret) {
		input_free_device(ptr);
		xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
		goto error;
	}
	info->ptr = ptr;

	ret = xenkbd_connect_backend(dev, info);
	if (ret < 0)
		goto error;

	return 0;

 error_nomem:
	ret = -ENOMEM;
	xenbus_dev_fatal(dev, ret, "allocating device memory");
 error:
	xenkbd_remove(dev);
	return ret;
}

static int xenkbd_resume(struct xenbus_device *dev)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);

	xenkbd_disconnect_backend(info);
	memset(info->page, 0, PAGE_SIZE);
	return xenkbd_connect_backend(dev, info);
}

static int xenkbd_remove(struct xenbus_device *dev)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);

	xenkbd_disconnect_backend(info);
	if (info->kbd)
		input_unregister_device(info->kbd);
	if (info->ptr)
		input_unregister_device(info->ptr);
	free_page((unsigned long)info->page);
	kfree(info);
	return 0;
}

static int xenkbd_connect_backend(struct xenbus_device *dev,
				  struct xenkbd_info *info)
{
	int ret, evtchn;
	struct xenbus_transaction xbt;

	ret = gnttab_grant_foreign_access(dev->otherend_id,
	                                  virt_to_mfn(info->page), 0);
	if (ret < 0)
		return ret;
	info->gref = ret;

	ret = xenbus_alloc_evtchn(dev, &evtchn);
	if (ret)
		goto error_grant;
	ret = bind_evtchn_to_irqhandler(evtchn, input_handler,
					0, dev->devicetype, info);
	if (ret < 0) {
		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
		goto error_evtchan;
	}
	info->irq = ret;

 again:
	ret = xenbus_transaction_start(&xbt);
	if (ret) {
		xenbus_dev_fatal(dev, ret, "starting transaction");
		goto error_irqh;
	}
	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
			    virt_to_mfn(info->page));
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "page-gref", "%u", info->gref);
	if (ret)
		goto error_xenbus;
	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
			    evtchn);
	if (ret)
		goto error_xenbus;
	ret = xenbus_transaction_end(xbt, 0);
	if (ret) {
		if (ret == -EAGAIN)
			goto again;
		xenbus_dev_fatal(dev, ret, "completing transaction");
		goto error_irqh;
	}

	xenbus_switch_state(dev, XenbusStateInitialised);
	return 0;

 error_xenbus:
	xenbus_transaction_end(xbt, 1);
	xenbus_dev_fatal(dev, ret, "writing xenstore");
 error_irqh:
	unbind_from_irqhandler(info->irq, info);
	info->irq = -1;
 error_evtchan:
	xenbus_free_evtchn(dev, evtchn);
 error_grant:
	gnttab_end_foreign_access_ref(info->gref, 0);
	info->gref = -1;
	return ret;
}

static void xenkbd_disconnect_backend(struct xenkbd_info *info)
{
	if (info->irq >= 0)
		unbind_from_irqhandler(info->irq, info);
	info->irq = -1;
	if (info->gref >= 0)
		gnttab_end_foreign_access_ref(info->gref, 0);
	info->gref = -1;
}

static void xenkbd_backend_changed(struct xenbus_device *dev,
				   enum xenbus_state backend_state)
{
	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
	int ret, val;

	switch (backend_state) {
	case XenbusStateInitialising:
	case XenbusStateInitialised:
	case XenbusStateReconfiguring:
	case XenbusStateReconfigured:
	case XenbusStateUnknown:
	case XenbusStateClosed:
		break;

	case XenbusStateInitWait:
InitWait:
		ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				   "feature-abs-pointer", "%d", &val);
		if (ret < 0)
			val = 0;
		if (val) {
			ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
					    "request-abs-pointer", "1");
			if (ret)
				pr_warning("xenkbd: can't request abs-pointer");
		}

		xenbus_switch_state(dev, XenbusStateConnected);
		break;

	case XenbusStateConnected:
		/*
		 * Work around xenbus race condition: If backend goes
		 * through InitWait to Connected fast enough, we can
		 * get Connected twice here.
		 */
		if (dev->state != XenbusStateConnected)
			goto InitWait; /* no InitWait seen yet, fudge it */

		/* Set input abs params to match backend screen res */
		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				 "width", "%d", &val) > 0)
			input_set_abs_params(info->ptr, ABS_X, 0, val, 0, 0);

		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
				 "height", "%d", &val) > 0)
			input_set_abs_params(info->ptr, ABS_Y, 0, val, 0, 0);

		break;

	case XenbusStateClosing:
		xenbus_frontend_closed(dev);
		break;
	}
}

static const struct xenbus_device_id xenkbd_ids[] = {
	{ "vkbd" },
	{ "" }
};

static struct xenbus_driver xenkbd_driver = {
	.name = "vkbd",
	.owner = THIS_MODULE,
	.ids = xenkbd_ids,
	.probe = xenkbd_probe,
	.remove = xenkbd_remove,
	.resume = xenkbd_resume,
	.otherend_changed = xenkbd_backend_changed,
};

static int __init xenkbd_init(void)
{
	if (!xen_pv_domain())
		return -ENODEV;

	/* Nothing to do if running in dom0. */
	if (xen_initial_domain())
		return -ENODEV;

	return xenbus_register_frontend(&xenkbd_driver);
}

static void __exit xenkbd_cleanup(void)
{
	xenbus_unregister_driver(&xenkbd_driver);
}

module_init(xenkbd_init);
module_exit(xenkbd_cleanup);

MODULE_DESCRIPTION("Xen virtual keyboard/pointer device frontend");
MODULE_LICENSE("GPL");
MODULE_ALIAS("xen:vkbd");
OpenPOWER on IntegriCloud