aboutsummaryrefslogtreecommitdiff
path: root/drivers/virtio/virtio_input.c
blob: f1f6208edcf59278522ceb52d5cc56d9be1889d1 (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
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/input.h>
#include <linux/slab.h>

#include <uapi/linux/virtio_ids.h>
#include <uapi/linux/virtio_input.h>

struct virtio_input {
	struct virtio_device       *vdev;
	struct input_dev           *idev;
	char                       name[64];
	char                       serial[64];
	char                       phys[64];
	struct virtqueue           *evt, *sts;
	struct virtio_input_event  evts[64];
	spinlock_t                 lock;
	bool                       ready;
};

static void virtinput_queue_evtbuf(struct virtio_input *vi,
				   struct virtio_input_event *evtbuf)
{
	struct scatterlist sg[1];

	sg_init_one(sg, evtbuf, sizeof(*evtbuf));
	virtqueue_add_inbuf(vi->evt, sg, 1, evtbuf, GFP_ATOMIC);
}

static void virtinput_recv_events(struct virtqueue *vq)
{
	struct virtio_input *vi = vq->vdev->priv;
	struct virtio_input_event *event;
	unsigned long flags;
	unsigned int len;

	spin_lock_irqsave(&vi->lock, flags);
	if (vi->ready) {
		while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {
			spin_unlock_irqrestore(&vi->lock, flags);
			input_event(vi->idev,
				    le16_to_cpu(event->type),
				    le16_to_cpu(event->code),
				    le32_to_cpu(event->value));
			spin_lock_irqsave(&vi->lock, flags);
			virtinput_queue_evtbuf(vi, event);
		}
		virtqueue_kick(vq);
	}
	spin_unlock_irqrestore(&vi->lock, flags);
}

/*
 * On error we are losing the status update, which isn't critical as
 * this is typically used for stuff like keyboard leds.
 */
static int virtinput_send_status(struct virtio_input *vi,
				 u16 type, u16 code, s32 value)
{
	struct virtio_input_event *stsbuf;
	struct scatterlist sg[1];
	unsigned long flags;
	int rc;

	stsbuf = kzalloc(sizeof(*stsbuf), GFP_ATOMIC);
	if (!stsbuf)
		return -ENOMEM;

	stsbuf->type  = cpu_to_le16(type);
	stsbuf->code  = cpu_to_le16(code);
	stsbuf->value = cpu_to_le32(value);
	sg_init_one(sg, stsbuf, sizeof(*stsbuf));

	spin_lock_irqsave(&vi->lock, flags);
	if (vi->ready) {
		rc = virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);
		virtqueue_kick(vi->sts);
	} else {
		rc = -ENODEV;
	}
	spin_unlock_irqrestore(&vi->lock, flags);

	if (rc != 0)
		kfree(stsbuf);
	return rc;
}

static void virtinput_recv_status(struct virtqueue *vq)
{
	struct virtio_input *vi = vq->vdev->priv;
	struct virtio_input_event *stsbuf;
	unsigned long flags;
	unsigned int len;

	spin_lock_irqsave(&vi->lock, flags);
	while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)
		kfree(stsbuf);
	spin_unlock_irqrestore(&vi->lock, flags);
}

static int virtinput_status(struct input_dev *idev, unsigned int type,
			    unsigned int code, int value)
{
	struct virtio_input *vi = input_get_drvdata(idev);

	return virtinput_send_status(vi, type, code, value);
}

static u8 virtinput_cfg_select(struct virtio_input *vi,
			       u8 select, u8 subsel)
{
	u8 size;

	virtio_cwrite_le(vi->vdev, struct virtio_input_config, select, &select);
	virtio_cwrite_le(vi->vdev, struct virtio_input_config, subsel, &subsel);
	virtio_cread_le(vi->vdev, struct virtio_input_config, size, &size);
	return size;
}

static void virtinput_cfg_bits(struct virtio_input *vi, int select, int subsel,
			       unsigned long *bits, unsigned int bitcount)
{
	unsigned int bit;
	u8 *virtio_bits;
	u8 bytes;

	bytes = virtinput_cfg_select(vi, select, subsel);
	if (!bytes)
		return;
	if (bitcount > bytes * 8)
		bitcount = bytes * 8;

	/*
	 * Bitmap in virtio config space is a simple stream of bytes,
	 * with the first byte carrying bits 0-7, second bits 8-15 and
	 * so on.
	 */
	virtio_bits = kzalloc(bytes, GFP_KERNEL);
	if (!virtio_bits)
		return;
	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
					      u.bitmap),
			   virtio_bits, bytes);
	for (bit = 0; bit < bitcount; bit++) {
		if (virtio_bits[bit / 8] & (1 << (bit % 8)))
			__set_bit(bit, bits);
	}
	kfree(virtio_bits);

	if (select == VIRTIO_INPUT_CFG_EV_BITS)
		__set_bit(subsel, vi->idev->evbit);
}

static void virtinput_cfg_abs(struct virtio_input *vi, int abs)
{
	u32 mi, ma, re, fu, fl;

	virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ABS_INFO, abs);
	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.min, &mi);
	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.max, &ma);
	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.res, &re);
	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);
	virtio_cread_le(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);
	input_set_abs_params(vi->idev, abs, mi, ma, fu, fl);
	input_abs_set_res(vi->idev, abs, re);
}

static int virtinput_init_vqs(struct virtio_input *vi)
{
	struct virtqueue *vqs[2];
	vq_callback_t *cbs[] = { virtinput_recv_events,
				 virtinput_recv_status };
	static const char * const names[] = { "events", "status" };
	int err;

	err = virtio_find_vqs(vi->vdev, 2, vqs, cbs, names, NULL);
	if (err)
		return err;
	vi->evt = vqs[0];
	vi->sts = vqs[1];

	return 0;
}

static void virtinput_fill_evt(struct virtio_input *vi)
{
	unsigned long flags;
	int i, size;

	spin_lock_irqsave(&vi->lock, flags);
	size = virtqueue_get_vring_size(vi->evt);
	if (size > ARRAY_SIZE(vi->evts))
		size = ARRAY_SIZE(vi->evts);
	for (i = 0; i < size; i++)
		virtinput_queue_evtbuf(vi, &vi->evts[i]);
	virtqueue_kick(vi->evt);
	spin_unlock_irqrestore(&vi->lock, flags);
}

static int virtinput_probe(struct virtio_device *vdev)
{
	struct virtio_input *vi;
	unsigned long flags;
	size_t size;
	int abs, err;

	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
		return -ENODEV;

	vi = kzalloc(sizeof(*vi), GFP_KERNEL);
	if (!vi)
		return -ENOMEM;

	vdev->priv = vi;
	vi->vdev = vdev;
	spin_lock_init(&vi->lock);

	err = virtinput_init_vqs(vi);
	if (err)
		goto err_init_vq;

	vi->idev = input_allocate_device();
	if (!vi->idev) {
		err = -ENOMEM;
		goto err_input_alloc;
	}
	input_set_drvdata(vi->idev, vi);

	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);
	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
					      u.string),
			   vi->name, min(size, sizeof(vi->name)));
	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);
	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
					      u.string),
			   vi->serial, min(size, sizeof(vi->serial)));
	snprintf(vi->phys, sizeof(vi->phys),
		 "virtio%d/input0", vdev->index);
	vi->idev->name = vi->name;
	vi->idev->phys = vi->phys;
	vi->idev->uniq = vi->serial;

	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);
	if (size >= sizeof(struct virtio_input_devids)) {
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.bustype, &vi->idev->id.bustype);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.vendor, &vi->idev->id.vendor);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.product, &vi->idev->id.product);
		virtio_cread_le(vi->vdev, struct virtio_input_config,
				u.ids.version, &vi->idev->id.version);
	} else {
		vi->idev->id.bustype = BUS_VIRTUAL;
	}

	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,
			   vi->idev->propbit, INPUT_PROP_CNT);
	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);
	if (size)
		__set_bit(EV_REP, vi->idev->evbit);

	vi->idev->dev.parent = &vdev->dev;
	vi->idev->event = virtinput_status;

	/* device -> kernel */
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,
			   vi->idev->keybit, KEY_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,
			   vi->idev->relbit, REL_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,
			   vi->idev->absbit, ABS_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,
			   vi->idev->mscbit, MSC_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,
			   vi->idev->swbit,  SW_CNT);

	/* kernel -> device */
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,
			   vi->idev->ledbit, LED_CNT);
	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,
			   vi->idev->sndbit, SND_CNT);

	if (test_bit(EV_ABS, vi->idev->evbit)) {
		for (abs = 0; abs < ABS_CNT; abs++) {
			if (!test_bit(abs, vi->idev->absbit))
				continue;
			virtinput_cfg_abs(vi, abs);
		}
	}

	virtio_device_ready(vdev);
	vi->ready = true;
	err = input_register_device(vi->idev);
	if (err)
		goto err_input_register;

	virtinput_fill_evt(vi);
	return 0;

err_input_register:
	spin_lock_irqsave(&vi->lock, flags);
	vi->ready = false;
	spin_unlock_irqrestore(&vi->lock, flags);
	input_free_device(vi->idev);
err_input_alloc:
	vdev->config->del_vqs(vdev);
err_init_vq:
	kfree(vi);
	return err;
}

static void virtinput_remove(struct virtio_device *vdev)
{
	struct virtio_input *vi = vdev->priv;
	void *buf;
	unsigned long flags;

	spin_lock_irqsave(&vi->lock, flags);
	vi->ready = false;
	spin_unlock_irqrestore(&vi->lock, flags);

	input_unregister_device(vi->idev);
	vdev->config->reset(vdev);
	while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)
		kfree(buf);
	vdev->config->del_vqs(vdev);
	kfree(vi);
}

#ifdef CONFIG_PM_SLEEP
static int virtinput_freeze(struct virtio_device *vdev)
{
	struct virtio_input *vi = vdev->priv;
	unsigned long flags;

	spin_lock_irqsave(&vi->lock, flags);
	vi->ready = false;
	spin_unlock_irqrestore(&vi->lock, flags);

	vdev->config->del_vqs(vdev);
	return 0;
}

static int virtinput_restore(struct virtio_device *vdev)
{
	struct virtio_input *vi = vdev->priv;
	int err;

	err = virtinput_init_vqs(vi);
	if (err)
		return err;

	virtio_device_ready(vdev);
	vi->ready = true;
	virtinput_fill_evt(vi);
	return 0;
}
#endif

static unsigned int features[] = {
	/* none */
};
static const struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

static struct virtio_driver virtio_input_driver = {
	.driver.name         = KBUILD_MODNAME,
	.driver.owner        = THIS_MODULE,
	.feature_table       = features,
	.feature_table_size  = ARRAY_SIZE(features),
	.id_table            = id_table,
	.probe               = virtinput_probe,
	.remove              = virtinput_remove,
#ifdef CONFIG_PM_SLEEP
	.freeze	             = virtinput_freeze,
	.restore             = virtinput_restore,
#endif
};

module_virtio_driver(virtio_input_driver);
MODULE_DEVICE_TABLE(virtio, id_table);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Virtio input device driver");
MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");