aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hid/hid-hyperv.c
blob: 6039f071fab1370da4a684e801883ef23e9706d4 (plain) (blame)
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
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
/*
 *  Copyright (c) 2009, Citrix Systems, Inc.
 *  Copyright (c) 2010, Microsoft Corporation.
 *  Copyright (c) 2011, Novell Inc.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms and conditions of the GNU General Public License,
 *  version 2, as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 *  more details.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/completion.h>
#include <linux/input.h>
#include <linux/hid.h>
#include <linux/hiddev.h>
#include <linux/hyperv.h>


struct hv_input_dev_info {
	unsigned int size;
	unsigned short vendor;
	unsigned short product;
	unsigned short version;
	unsigned short reserved[11];
};

/* The maximum size of a synthetic input message. */
#define SYNTHHID_MAX_INPUT_REPORT_SIZE 16

/*
 * Current version
 *
 * History:
 * Beta, RC < 2008/1/22        1,0
 * RC > 2008/1/22              2,0
 */
#define SYNTHHID_INPUT_VERSION_MAJOR	2
#define SYNTHHID_INPUT_VERSION_MINOR	0
#define SYNTHHID_INPUT_VERSION		(SYNTHHID_INPUT_VERSION_MINOR | \
					 (SYNTHHID_INPUT_VERSION_MAJOR << 16))


#pragma pack(push, 1)
/*
 * Message types in the synthetic input protocol
 */
enum synthhid_msg_type {
	SYNTH_HID_PROTOCOL_REQUEST,
	SYNTH_HID_PROTOCOL_RESPONSE,
	SYNTH_HID_INITIAL_DEVICE_INFO,
	SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
	SYNTH_HID_INPUT_REPORT,
	SYNTH_HID_MAX
};

/*
 * Basic message structures.
 */
struct synthhid_msg_hdr {
	enum synthhid_msg_type type;
	u32 size;
};

struct synthhid_msg {
	struct synthhid_msg_hdr header;
	char data[1]; /* Enclosed message */
};

union synthhid_version {
	struct {
		u16 minor_version;
		u16 major_version;
	};
	u32 version;
};

/*
 * Protocol messages
 */
struct synthhid_protocol_request {
	struct synthhid_msg_hdr header;
	union synthhid_version version_requested;
};

struct synthhid_protocol_response {
	struct synthhid_msg_hdr header;
	union synthhid_version version_requested;
	unsigned char approved;
};

struct synthhid_device_info {
	struct synthhid_msg_hdr header;
	struct hv_input_dev_info hid_dev_info;
	struct hid_descriptor hid_descriptor;
};

struct synthhid_device_info_ack {
	struct synthhid_msg_hdr header;
	unsigned char reserved;
};

struct synthhid_input_report {
	struct synthhid_msg_hdr header;
	char buffer[1];
};

#pragma pack(pop)

#define INPUTVSC_SEND_RING_BUFFER_SIZE		(10*PAGE_SIZE)
#define INPUTVSC_RECV_RING_BUFFER_SIZE		(10*PAGE_SIZE)


enum pipe_prot_msg_type {
	PIPE_MESSAGE_INVALID,
	PIPE_MESSAGE_DATA,
	PIPE_MESSAGE_MAXIMUM
};


struct pipe_prt_msg {
	enum pipe_prot_msg_type type;
	u32 size;
	char data[1];
};

struct  mousevsc_prt_msg {
	enum pipe_prot_msg_type type;
	u32 size;
	union {
		struct synthhid_protocol_request request;
		struct synthhid_protocol_response response;
		struct synthhid_device_info_ack ack;
	};
};

/*
 * Represents an mousevsc device
 */
struct mousevsc_dev {
	struct hv_device	*device;
	bool			init_complete;
	bool			connected;
	struct mousevsc_prt_msg	protocol_req;
	struct mousevsc_prt_msg	protocol_resp;
	/* Synchronize the request/response if needed */
	struct completion	wait_event;
	int			dev_info_status;

	struct hid_descriptor	*hid_desc;
	unsigned char		*report_desc;
	u32			report_desc_size;
	struct hv_input_dev_info hid_dev_info;
	struct hid_device       *hid_device;
	u8			input_buf[HID_MAX_BUFFER_SIZE];
};


static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
{
	struct mousevsc_dev *input_dev;

	input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);

	if (!input_dev)
		return NULL;

	input_dev->device = device;
	hv_set_drvdata(device, input_dev);
	init_completion(&input_dev->wait_event);
	input_dev->init_complete = false;

	return input_dev;
}

static void mousevsc_free_device(struct mousevsc_dev *device)
{
	kfree(device->hid_desc);
	kfree(device->report_desc);
	hv_set_drvdata(device->device, NULL);
	kfree(device);
}

static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
				struct synthhid_device_info *device_info)
{
	int ret = 0;
	struct hid_descriptor *desc;
	struct mousevsc_prt_msg ack;

	input_device->dev_info_status = -ENOMEM;

	input_device->hid_dev_info = device_info->hid_dev_info;
	desc = &device_info->hid_descriptor;
	if (desc->bLength == 0)
		goto cleanup;

	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);

	if (!input_device->hid_desc)
		goto cleanup;

	input_device->report_desc_size = desc->desc[0].wDescriptorLength;
	if (input_device->report_desc_size == 0) {
		input_device->dev_info_status = -EINVAL;
		goto cleanup;
	}

	input_device->report_desc = kzalloc(input_device->report_desc_size,
					  GFP_ATOMIC);

	if (!input_device->report_desc) {
		input_device->dev_info_status = -ENOMEM;
		goto cleanup;
	}

	memcpy(input_device->report_desc,
	       ((unsigned char *)desc) + desc->bLength,
	       desc->desc[0].wDescriptorLength);

	/* Send the ack */
	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));

	ack.type = PIPE_MESSAGE_DATA;
	ack.size = sizeof(struct synthhid_device_info_ack);

	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
	ack.ack.header.size = 1;
	ack.ack.reserved = 0;

	ret = vmbus_sendpacket(input_device->device->channel,
			&ack,
			sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
			sizeof(struct synthhid_device_info_ack),
			(unsigned long)&ack,
			VM_PKT_DATA_INBAND,
			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

	if (!ret)
		input_device->dev_info_status = 0;

cleanup:
	complete(&input_device->wait_event);

	return;
}

static void mousevsc_on_receive(struct hv_device *device,
				struct vmpacket_descriptor *packet)
{
	struct pipe_prt_msg *pipe_msg;
	struct synthhid_msg *hid_msg;
	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
	struct synthhid_input_report *input_report;
	size_t len;

	pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
						(packet->offset8 << 3));

	if (pipe_msg->type != PIPE_MESSAGE_DATA)
		return;

	hid_msg = (struct synthhid_msg *)pipe_msg->data;

	switch (hid_msg->header.type) {
	case SYNTH_HID_PROTOCOL_RESPONSE:
		/*
		 * While it will be impossible for us to protect against
		 * malicious/buggy hypervisor/host, add a check here to
		 * ensure we don't corrupt memory.
		 */
		if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
			- sizeof(unsigned char))
			> sizeof(struct mousevsc_prt_msg)) {
			WARN_ON(1);
			break;
		}

		memcpy(&input_dev->protocol_resp, pipe_msg,
		       pipe_msg->size + sizeof(struct pipe_prt_msg) -
		       sizeof(unsigned char));
		complete(&input_dev->wait_event);
		break;

	case SYNTH_HID_INITIAL_DEVICE_INFO:
		WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));

		/*
		 * Parse out the device info into device attr,
		 * hid desc and report desc
		 */
		mousevsc_on_receive_device_info(input_dev,
			(struct synthhid_device_info *)pipe_msg->data);
		break;
	case SYNTH_HID_INPUT_REPORT:
		input_report =
			(struct synthhid_input_report *)pipe_msg->data;
		if (!input_dev->init_complete)
			break;

		len = min(input_report->header.size,
			  (u32)sizeof(input_dev->input_buf));
		memcpy(input_dev->input_buf, input_report->buffer, len);
		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
				 input_dev->input_buf, len, 1);

		pm_wakeup_event(&input_dev->device->device, 0);

		break;
	default:
		pr_err("unsupported hid msg type - type %d len %d",
		       hid_msg->header.type, hid_msg->header.size);
		break;
	}

}

static void mousevsc_on_channel_callback(void *context)
{
	const int packet_size = 0x100;
	int ret;
	struct hv_device *device = context;
	u32 bytes_recvd;
	u64 req_id;
	struct vmpacket_descriptor *desc;
	unsigned char	*buffer;
	int	bufferlen = packet_size;

	buffer = kmalloc(bufferlen, GFP_ATOMIC);
	if (!buffer)
		return;

	do {
		ret = vmbus_recvpacket_raw(device->channel, buffer,
					bufferlen, &bytes_recvd, &req_id);

		switch (ret) {
		case 0:
			if (bytes_recvd <= 0) {
				kfree(buffer);
				return;
			}
			desc = (struct vmpacket_descriptor *)buffer;

			switch (desc->type) {
			case VM_PKT_COMP:
				break;

			case VM_PKT_DATA_INBAND:
				mousevsc_on_receive(device, desc);
				break;

			default:
				pr_err("unhandled packet type %d, tid %llx len %d\n",
					desc->type, req_id, bytes_recvd);
				break;
			}

			break;

		case -ENOBUFS:
			kfree(buffer);
			/* Handle large packet */
			bufferlen = bytes_recvd;
			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);

			if (!buffer)
				return;

			break;
		}
	} while (1);

}

static int mousevsc_connect_to_vsp(struct hv_device *device)
{
	int ret = 0;
	unsigned long t;
	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
	struct mousevsc_prt_msg *request;
	struct mousevsc_prt_msg *response;

	request = &input_dev->protocol_req;
	memset(request, 0, sizeof(struct mousevsc_prt_msg));

	request->type = PIPE_MESSAGE_DATA;
	request->size = sizeof(struct synthhid_protocol_request);
	request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
	request->request.header.size = sizeof(unsigned int);
	request->request.version_requested.version = SYNTHHID_INPUT_VERSION;

	ret = vmbus_sendpacket(device->channel, request,
				sizeof(struct pipe_prt_msg) -
				sizeof(unsigned char) +
				sizeof(struct synthhid_protocol_request),
				(unsigned long)request,
				VM_PKT_DATA_INBAND,
				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
	if (ret)
		goto cleanup;

	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
	if (!t) {
		ret = -ETIMEDOUT;
		goto cleanup;
	}

	response = &input_dev->protocol_resp;

	if (!response->response.approved) {
		pr_err("synthhid protocol request failed (version %d)\n",
		       SYNTHHID_INPUT_VERSION);
		ret = -ENODEV;
		goto cleanup;
	}

	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
	if (!t) {
		ret = -ETIMEDOUT;
		goto cleanup;
	}

	/*
	 * We should have gotten the device attr, hid desc and report
	 * desc at this point
	 */
	ret = input_dev->dev_info_status;

cleanup:
	return ret;
}

static int mousevsc_hid_parse(struct hid_device *hid)
{
	struct hv_device *dev = hid_get_drvdata(hid);
	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);

	return hid_parse_report(hid, input_dev->report_desc,
				input_dev->report_desc_size);
}

static int mousevsc_hid_open(struct hid_device *hid)
{
	return 0;
}

static int mousevsc_hid_start(struct hid_device *hid)
{
	return 0;
}

static void mousevsc_hid_close(struct hid_device *hid)
{
}

static void mousevsc_hid_stop(struct hid_device *hid)
{
}

static int mousevsc_hid_raw_request(struct hid_device *hid,
				    unsigned char report_num,
				    __u8 *buf, size_t len,
				    unsigned char rtype,
				    int reqtype)
{
	return 0;
}

static struct hid_ll_driver mousevsc_ll_driver = {
	.parse = mousevsc_hid_parse,
	.open = mousevsc_hid_open,
	.close = mousevsc_hid_close,
	.start = mousevsc_hid_start,
	.stop = mousevsc_hid_stop,
	.raw_request = mousevsc_hid_raw_request,
};

static struct hid_driver mousevsc_hid_driver;

static int mousevsc_probe(struct hv_device *device,
			const struct hv_vmbus_device_id *dev_id)
{
	int ret;
	struct mousevsc_dev *input_dev;
	struct hid_device *hid_dev;

	input_dev = mousevsc_alloc_device(device);

	if (!input_dev)
		return -ENOMEM;

	ret = vmbus_open(device->channel,
		INPUTVSC_SEND_RING_BUFFER_SIZE,
		INPUTVSC_RECV_RING_BUFFER_SIZE,
		NULL,
		0,
		mousevsc_on_channel_callback,
		device
		);

	if (ret)
		goto probe_err0;

	ret = mousevsc_connect_to_vsp(device);

	if (ret)
		goto probe_err1;

	/* workaround SA-167 */
	if (input_dev->report_desc[14] == 0x25)
		input_dev->report_desc[14] = 0x29;

	hid_dev = hid_allocate_device();
	if (IS_ERR(hid_dev)) {
		ret = PTR_ERR(hid_dev);
		goto probe_err1;
	}

	hid_dev->ll_driver = &mousevsc_ll_driver;
	hid_dev->driver = &mousevsc_hid_driver;
	hid_dev->bus = BUS_VIRTUAL;
	hid_dev->vendor = input_dev->hid_dev_info.vendor;
	hid_dev->product = input_dev->hid_dev_info.product;
	hid_dev->version = input_dev->hid_dev_info.version;
	input_dev->hid_device = hid_dev;

	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");

	hid_set_drvdata(hid_dev, device);

	ret = hid_add_device(hid_dev);
	if (ret)
		goto probe_err1;


	ret = hid_parse(hid_dev);
	if (ret) {
		hid_err(hid_dev, "parse failed\n");
		goto probe_err2;
	}

	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);

	if (ret) {
		hid_err(hid_dev, "hw start failed\n");
		goto probe_err2;
	}

	device_init_wakeup(&device->device, true);

	input_dev->connected = true;
	input_dev->init_complete = true;

	return ret;

probe_err2:
	hid_destroy_device(hid_dev);

probe_err1:
	vmbus_close(device->channel);

probe_err0:
	mousevsc_free_device(input_dev);

	return ret;
}


static int mousevsc_remove(struct hv_device *dev)
{
	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);

	device_init_wakeup(&dev->device, false);
	vmbus_close(dev->channel);
	hid_hw_stop(input_dev->hid_device);
	hid_destroy_device(input_dev->hid_device);
	mousevsc_free_device(input_dev);

	return 0;
}

static const struct hv_vmbus_device_id id_table[] = {
	/* Mouse guid */
	{ HV_MOUSE_GUID, },
	{ },
};

MODULE_DEVICE_TABLE(vmbus, id_table);

static struct  hv_driver mousevsc_drv = {
	.name = KBUILD_MODNAME,
	.id_table = id_table,
	.probe = mousevsc_probe,
	.remove = mousevsc_remove,
};

static int __init mousevsc_init(void)
{
	return vmbus_driver_register(&mousevsc_drv);
}

static void __exit mousevsc_exit(void)
{
	vmbus_driver_unregister(&mousevsc_drv);
}

MODULE_LICENSE("GPL");
module_init(mousevsc_init);
module_exit(mousevsc_exit);