1#include <linux/module.h>
2#include <linux/virtio.h>
3#include <linux/virtio_config.h>
4#include <linux/input.h>
5
6#include <uapi/linux/virtio_ids.h>
7#include <uapi/linux/virtio_input.h>
8
9struct virtio_input {
10	struct virtio_device       *vdev;
11	struct input_dev           *idev;
12	char                       name[64];
13	char                       serial[64];
14	char                       phys[64];
15	struct virtqueue           *evt, *sts;
16	struct virtio_input_event  evts[64];
17	spinlock_t                 lock;
18	bool                       ready;
19};
20
21static void virtinput_queue_evtbuf(struct virtio_input *vi,
22				   struct virtio_input_event *evtbuf)
23{
24	struct scatterlist sg[1];
25
26	sg_init_one(sg, evtbuf, sizeof(*evtbuf));
27	virtqueue_add_inbuf(vi->evt, sg, 1, evtbuf, GFP_ATOMIC);
28}
29
30static void virtinput_recv_events(struct virtqueue *vq)
31{
32	struct virtio_input *vi = vq->vdev->priv;
33	struct virtio_input_event *event;
34	unsigned long flags;
35	unsigned int len;
36
37	spin_lock_irqsave(&vi->lock, flags);
38	if (vi->ready) {
39		while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {
40			spin_unlock_irqrestore(&vi->lock, flags);
41			input_event(vi->idev,
42				    le16_to_cpu(event->type),
43				    le16_to_cpu(event->code),
44				    le32_to_cpu(event->value));
45			spin_lock_irqsave(&vi->lock, flags);
46			virtinput_queue_evtbuf(vi, event);
47		}
48		virtqueue_kick(vq);
49	}
50	spin_unlock_irqrestore(&vi->lock, flags);
51}
52
53/*
54 * On error we are losing the status update, which isn't critical as
55 * this is typically used for stuff like keyboard leds.
56 */
57static int virtinput_send_status(struct virtio_input *vi,
58				 u16 type, u16 code, s32 value)
59{
60	struct virtio_input_event *stsbuf;
61	struct scatterlist sg[1];
62	unsigned long flags;
63	int rc;
64
65	stsbuf = kzalloc(sizeof(*stsbuf), GFP_ATOMIC);
66	if (!stsbuf)
67		return -ENOMEM;
68
69	stsbuf->type  = cpu_to_le16(type);
70	stsbuf->code  = cpu_to_le16(code);
71	stsbuf->value = cpu_to_le32(value);
72	sg_init_one(sg, stsbuf, sizeof(*stsbuf));
73
74	spin_lock_irqsave(&vi->lock, flags);
75	if (vi->ready) {
76		rc = virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);
77		virtqueue_kick(vi->sts);
78	} else {
79		rc = -ENODEV;
80	}
81	spin_unlock_irqrestore(&vi->lock, flags);
82
83	if (rc != 0)
84		kfree(stsbuf);
85	return rc;
86}
87
88static void virtinput_recv_status(struct virtqueue *vq)
89{
90	struct virtio_input *vi = vq->vdev->priv;
91	struct virtio_input_event *stsbuf;
92	unsigned long flags;
93	unsigned int len;
94
95	spin_lock_irqsave(&vi->lock, flags);
96	while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)
97		kfree(stsbuf);
98	spin_unlock_irqrestore(&vi->lock, flags);
99}
100
101static int virtinput_status(struct input_dev *idev, unsigned int type,
102			    unsigned int code, int value)
103{
104	struct virtio_input *vi = input_get_drvdata(idev);
105
106	return virtinput_send_status(vi, type, code, value);
107}
108
109static u8 virtinput_cfg_select(struct virtio_input *vi,
110			       u8 select, u8 subsel)
111{
112	u8 size;
113
114	virtio_cwrite(vi->vdev, struct virtio_input_config, select, &select);
115	virtio_cwrite(vi->vdev, struct virtio_input_config, subsel, &subsel);
116	virtio_cread(vi->vdev, struct virtio_input_config, size, &size);
117	return size;
118}
119
120static void virtinput_cfg_bits(struct virtio_input *vi, int select, int subsel,
121			       unsigned long *bits, unsigned int bitcount)
122{
123	unsigned int bit;
124	u8 *virtio_bits;
125	u8 bytes;
126
127	bytes = virtinput_cfg_select(vi, select, subsel);
128	if (!bytes)
129		return;
130	if (bitcount > bytes * 8)
131		bitcount = bytes * 8;
132
133	/*
134	 * Bitmap in virtio config space is a simple stream of bytes,
135	 * with the first byte carrying bits 0-7, second bits 8-15 and
136	 * so on.
137	 */
138	virtio_bits = kzalloc(bytes, GFP_KERNEL);
139	if (!virtio_bits)
140		return;
141	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
142					      u.bitmap),
143			   virtio_bits, bytes);
144	for (bit = 0; bit < bitcount; bit++) {
145		if (virtio_bits[bit / 8] & (1 << (bit % 8)))
146			__set_bit(bit, bits);
147	}
148	kfree(virtio_bits);
149
150	if (select == VIRTIO_INPUT_CFG_EV_BITS)
151		__set_bit(subsel, vi->idev->evbit);
152}
153
154static void virtinput_cfg_abs(struct virtio_input *vi, int abs)
155{
156	u32 mi, ma, re, fu, fl;
157
158	virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ABS_INFO, abs);
159	virtio_cread(vi->vdev, struct virtio_input_config, u.abs.min, &mi);
160	virtio_cread(vi->vdev, struct virtio_input_config, u.abs.max, &ma);
161	virtio_cread(vi->vdev, struct virtio_input_config, u.abs.res, &re);
162	virtio_cread(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);
163	virtio_cread(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);
164	input_set_abs_params(vi->idev, abs, mi, ma, fu, fl);
165	input_abs_set_res(vi->idev, abs, re);
166}
167
168static int virtinput_init_vqs(struct virtio_input *vi)
169{
170	struct virtqueue *vqs[2];
171	vq_callback_t *cbs[] = { virtinput_recv_events,
172				 virtinput_recv_status };
173	static const char *names[] = { "events", "status" };
174	int err;
175
176	err = vi->vdev->config->find_vqs(vi->vdev, 2, vqs, cbs, names);
177	if (err)
178		return err;
179	vi->evt = vqs[0];
180	vi->sts = vqs[1];
181
182	return 0;
183}
184
185static void virtinput_fill_evt(struct virtio_input *vi)
186{
187	unsigned long flags;
188	int i, size;
189
190	spin_lock_irqsave(&vi->lock, flags);
191	size = virtqueue_get_vring_size(vi->evt);
192	if (size > ARRAY_SIZE(vi->evts))
193		size = ARRAY_SIZE(vi->evts);
194	for (i = 0; i < size; i++)
195		virtinput_queue_evtbuf(vi, &vi->evts[i]);
196	virtqueue_kick(vi->evt);
197	spin_unlock_irqrestore(&vi->lock, flags);
198}
199
200static int virtinput_probe(struct virtio_device *vdev)
201{
202	struct virtio_input *vi;
203	unsigned long flags;
204	size_t size;
205	int abs, err;
206
207	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
208		return -ENODEV;
209
210	vi = kzalloc(sizeof(*vi), GFP_KERNEL);
211	if (!vi)
212		return -ENOMEM;
213
214	vdev->priv = vi;
215	vi->vdev = vdev;
216	spin_lock_init(&vi->lock);
217
218	err = virtinput_init_vqs(vi);
219	if (err)
220		goto err_init_vq;
221
222	vi->idev = input_allocate_device();
223	if (!vi->idev) {
224		err = -ENOMEM;
225		goto err_input_alloc;
226	}
227	input_set_drvdata(vi->idev, vi);
228
229	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);
230	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
231					      u.string),
232			   vi->name, min(size, sizeof(vi->name)));
233	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);
234	virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
235					      u.string),
236			   vi->serial, min(size, sizeof(vi->serial)));
237	snprintf(vi->phys, sizeof(vi->phys),
238		 "virtio%d/input0", vdev->index);
239	vi->idev->name = vi->name;
240	vi->idev->phys = vi->phys;
241	vi->idev->uniq = vi->serial;
242
243	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);
244	if (size >= sizeof(struct virtio_input_devids)) {
245		virtio_cread(vi->vdev, struct virtio_input_config,
246			     u.ids.bustype, &vi->idev->id.bustype);
247		virtio_cread(vi->vdev, struct virtio_input_config,
248			     u.ids.vendor, &vi->idev->id.vendor);
249		virtio_cread(vi->vdev, struct virtio_input_config,
250			     u.ids.product, &vi->idev->id.product);
251		virtio_cread(vi->vdev, struct virtio_input_config,
252			     u.ids.version, &vi->idev->id.version);
253	} else {
254		vi->idev->id.bustype = BUS_VIRTUAL;
255	}
256
257	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,
258			   vi->idev->propbit, INPUT_PROP_CNT);
259	size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);
260	if (size)
261		__set_bit(EV_REP, vi->idev->evbit);
262
263	vi->idev->dev.parent = &vdev->dev;
264	vi->idev->event = virtinput_status;
265
266	/* device -> kernel */
267	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,
268			   vi->idev->keybit, KEY_CNT);
269	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,
270			   vi->idev->relbit, REL_CNT);
271	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,
272			   vi->idev->absbit, ABS_CNT);
273	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,
274			   vi->idev->mscbit, MSC_CNT);
275	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,
276			   vi->idev->swbit,  SW_CNT);
277
278	/* kernel -> device */
279	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,
280			   vi->idev->ledbit, LED_CNT);
281	virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,
282			   vi->idev->sndbit, SND_CNT);
283
284	if (test_bit(EV_ABS, vi->idev->evbit)) {
285		for (abs = 0; abs < ABS_CNT; abs++) {
286			if (!test_bit(abs, vi->idev->absbit))
287				continue;
288			virtinput_cfg_abs(vi, abs);
289		}
290	}
291
292	virtio_device_ready(vdev);
293	vi->ready = true;
294	err = input_register_device(vi->idev);
295	if (err)
296		goto err_input_register;
297
298	virtinput_fill_evt(vi);
299	return 0;
300
301err_input_register:
302	spin_lock_irqsave(&vi->lock, flags);
303	vi->ready = false;
304	spin_unlock_irqrestore(&vi->lock, flags);
305	input_free_device(vi->idev);
306err_input_alloc:
307	vdev->config->del_vqs(vdev);
308err_init_vq:
309	kfree(vi);
310	return err;
311}
312
313static void virtinput_remove(struct virtio_device *vdev)
314{
315	struct virtio_input *vi = vdev->priv;
316	void *buf;
317	unsigned long flags;
318
319	spin_lock_irqsave(&vi->lock, flags);
320	vi->ready = false;
321	spin_unlock_irqrestore(&vi->lock, flags);
322
323	input_unregister_device(vi->idev);
324	vdev->config->reset(vdev);
325	while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)
326		kfree(buf);
327	vdev->config->del_vqs(vdev);
328	kfree(vi);
329}
330
331#ifdef CONFIG_PM_SLEEP
332static int virtinput_freeze(struct virtio_device *vdev)
333{
334	struct virtio_input *vi = vdev->priv;
335	unsigned long flags;
336
337	spin_lock_irqsave(&vi->lock, flags);
338	vi->ready = false;
339	spin_unlock_irqrestore(&vi->lock, flags);
340
341	vdev->config->del_vqs(vdev);
342	return 0;
343}
344
345static int virtinput_restore(struct virtio_device *vdev)
346{
347	struct virtio_input *vi = vdev->priv;
348	int err;
349
350	err = virtinput_init_vqs(vi);
351	if (err)
352		return err;
353
354	virtio_device_ready(vdev);
355	vi->ready = true;
356	virtinput_fill_evt(vi);
357	return 0;
358}
359#endif
360
361static unsigned int features[] = {
362	/* none */
363};
364static struct virtio_device_id id_table[] = {
365	{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
366	{ 0 },
367};
368
369static struct virtio_driver virtio_input_driver = {
370	.driver.name         = KBUILD_MODNAME,
371	.driver.owner        = THIS_MODULE,
372	.feature_table       = features,
373	.feature_table_size  = ARRAY_SIZE(features),
374	.id_table            = id_table,
375	.probe               = virtinput_probe,
376	.remove              = virtinput_remove,
377#ifdef CONFIG_PM_SLEEP
378	.freeze	             = virtinput_freeze,
379	.restore             = virtinput_restore,
380#endif
381};
382
383module_virtio_driver(virtio_input_driver);
384MODULE_DEVICE_TABLE(virtio, id_table);
385
386MODULE_LICENSE("GPL");
387MODULE_DESCRIPTION("Virtio input device driver");
388MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");
389