1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
3 #include <linux/virtio.h>
4 #include <linux/virtio_config.h>
5 #include <linux/input.h>
6 #include <linux/input/mt.h>
7
8 #include <uapi/linux/virtio_ids.h>
9 #include <uapi/linux/virtio_input.h>
10
11 struct virtio_input {
12 struct virtio_device *vdev;
13 struct input_dev *idev;
14 char name[64];
15 char serial[64];
16 char phys[64];
17 struct virtqueue *evt, *sts;
18 struct virtio_input_event evts[64];
19 spinlock_t lock;
20 bool ready;
21 };
22
virtinput_queue_evtbuf(struct virtio_input * vi,struct virtio_input_event * evtbuf)23 static void virtinput_queue_evtbuf(struct virtio_input *vi,
24 struct virtio_input_event *evtbuf)
25 {
26 struct scatterlist sg[1];
27
28 sg_init_one(sg, evtbuf, sizeof(*evtbuf));
29 virtqueue_add_inbuf(vi->evt, sg, 1, evtbuf, GFP_ATOMIC);
30 }
31
virtinput_recv_events(struct virtqueue * vq)32 static void virtinput_recv_events(struct virtqueue *vq)
33 {
34 struct virtio_input *vi = vq->vdev->priv;
35 struct virtio_input_event *event;
36 unsigned long flags;
37 unsigned int len;
38
39 spin_lock_irqsave(&vi->lock, flags);
40 if (vi->ready) {
41 while ((event = virtqueue_get_buf(vi->evt, &len)) != NULL) {
42 spin_unlock_irqrestore(&vi->lock, flags);
43 input_event(vi->idev,
44 le16_to_cpu(event->type),
45 le16_to_cpu(event->code),
46 le32_to_cpu(event->value));
47 spin_lock_irqsave(&vi->lock, flags);
48 virtinput_queue_evtbuf(vi, event);
49 }
50 virtqueue_kick(vq);
51 }
52 spin_unlock_irqrestore(&vi->lock, flags);
53 }
54
55 /*
56 * On error we are losing the status update, which isn't critical as
57 * this is typically used for stuff like keyboard leds.
58 */
virtinput_send_status(struct virtio_input * vi,u16 type,u16 code,s32 value)59 static int virtinput_send_status(struct virtio_input *vi,
60 u16 type, u16 code, s32 value)
61 {
62 struct virtio_input_event *stsbuf;
63 struct scatterlist sg[1];
64 unsigned long flags;
65 int rc;
66
67 stsbuf = kzalloc(sizeof(*stsbuf), GFP_ATOMIC);
68 if (!stsbuf)
69 return -ENOMEM;
70
71 stsbuf->type = cpu_to_le16(type);
72 stsbuf->code = cpu_to_le16(code);
73 stsbuf->value = cpu_to_le32(value);
74 sg_init_one(sg, stsbuf, sizeof(*stsbuf));
75
76 spin_lock_irqsave(&vi->lock, flags);
77 if (vi->ready) {
78 rc = virtqueue_add_outbuf(vi->sts, sg, 1, stsbuf, GFP_ATOMIC);
79 virtqueue_kick(vi->sts);
80 } else {
81 rc = -ENODEV;
82 }
83 spin_unlock_irqrestore(&vi->lock, flags);
84
85 if (rc != 0)
86 kfree(stsbuf);
87 return rc;
88 }
89
virtinput_recv_status(struct virtqueue * vq)90 static void virtinput_recv_status(struct virtqueue *vq)
91 {
92 struct virtio_input *vi = vq->vdev->priv;
93 struct virtio_input_event *stsbuf;
94 unsigned long flags;
95 unsigned int len;
96
97 spin_lock_irqsave(&vi->lock, flags);
98 while ((stsbuf = virtqueue_get_buf(vi->sts, &len)) != NULL)
99 kfree(stsbuf);
100 spin_unlock_irqrestore(&vi->lock, flags);
101 }
102
virtinput_status(struct input_dev * idev,unsigned int type,unsigned int code,int value)103 static int virtinput_status(struct input_dev *idev, unsigned int type,
104 unsigned int code, int value)
105 {
106 struct virtio_input *vi = input_get_drvdata(idev);
107
108 return virtinput_send_status(vi, type, code, value);
109 }
110
virtinput_cfg_select(struct virtio_input * vi,u8 select,u8 subsel)111 static u8 virtinput_cfg_select(struct virtio_input *vi,
112 u8 select, u8 subsel)
113 {
114 u8 size;
115
116 virtio_cwrite(vi->vdev, struct virtio_input_config, select, &select);
117 virtio_cwrite(vi->vdev, struct virtio_input_config, subsel, &subsel);
118 virtio_cread(vi->vdev, struct virtio_input_config, size, &size);
119 return size;
120 }
121
virtinput_cfg_bits(struct virtio_input * vi,int select,int subsel,unsigned long * bits,unsigned int bitcount)122 static void virtinput_cfg_bits(struct virtio_input *vi, int select, int subsel,
123 unsigned long *bits, unsigned int bitcount)
124 {
125 unsigned int bit;
126 u8 *virtio_bits;
127 u8 bytes;
128
129 bytes = virtinput_cfg_select(vi, select, subsel);
130 if (!bytes)
131 return;
132 if (bitcount > bytes * 8)
133 bitcount = bytes * 8;
134
135 /*
136 * Bitmap in virtio config space is a simple stream of bytes,
137 * with the first byte carrying bits 0-7, second bits 8-15 and
138 * so on.
139 */
140 virtio_bits = kzalloc(bytes, GFP_KERNEL);
141 if (!virtio_bits)
142 return;
143 virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
144 u.bitmap),
145 virtio_bits, bytes);
146 for (bit = 0; bit < bitcount; bit++) {
147 if (virtio_bits[bit / 8] & (1 << (bit % 8)))
148 __set_bit(bit, bits);
149 }
150 kfree(virtio_bits);
151
152 if (select == VIRTIO_INPUT_CFG_EV_BITS)
153 __set_bit(subsel, vi->idev->evbit);
154 }
155
virtinput_cfg_abs(struct virtio_input * vi,int abs)156 static void virtinput_cfg_abs(struct virtio_input *vi, int abs)
157 {
158 u32 mi, ma, re, fu, fl;
159
160 virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ABS_INFO, abs);
161 virtio_cread(vi->vdev, struct virtio_input_config, u.abs.min, &mi);
162 virtio_cread(vi->vdev, struct virtio_input_config, u.abs.max, &ma);
163 virtio_cread(vi->vdev, struct virtio_input_config, u.abs.res, &re);
164 virtio_cread(vi->vdev, struct virtio_input_config, u.abs.fuzz, &fu);
165 virtio_cread(vi->vdev, struct virtio_input_config, u.abs.flat, &fl);
166 input_set_abs_params(vi->idev, abs, mi, ma, fu, fl);
167 input_abs_set_res(vi->idev, abs, re);
168 if (abs == ABS_MT_TRACKING_ID) {
169 unsigned int slot_flags =
170 test_bit(INPUT_PROP_DIRECT, vi->idev->propbit) ?
171 INPUT_MT_DIRECT : 0;
172
173 input_mt_init_slots(vi->idev,
174 ma, /* input max finger */
175 slot_flags);
176 }
177 }
178
virtinput_init_vqs(struct virtio_input * vi)179 static int virtinput_init_vqs(struct virtio_input *vi)
180 {
181 struct virtqueue *vqs[2];
182 vq_callback_t *cbs[] = { virtinput_recv_events,
183 virtinput_recv_status };
184 static const char * const names[] = { "events", "status" };
185 int err;
186
187 err = virtio_find_vqs(vi->vdev, 2, vqs, cbs, names, NULL);
188 if (err)
189 return err;
190 vi->evt = vqs[0];
191 vi->sts = vqs[1];
192
193 return 0;
194 }
195
virtinput_fill_evt(struct virtio_input * vi)196 static void virtinput_fill_evt(struct virtio_input *vi)
197 {
198 unsigned long flags;
199 int i, size;
200
201 spin_lock_irqsave(&vi->lock, flags);
202 size = virtqueue_get_vring_size(vi->evt);
203 if (size > ARRAY_SIZE(vi->evts))
204 size = ARRAY_SIZE(vi->evts);
205 for (i = 0; i < size; i++)
206 virtinput_queue_evtbuf(vi, &vi->evts[i]);
207 virtqueue_kick(vi->evt);
208 spin_unlock_irqrestore(&vi->lock, flags);
209 }
210
virtinput_probe(struct virtio_device * vdev)211 static int virtinput_probe(struct virtio_device *vdev)
212 {
213 struct virtio_input *vi;
214 unsigned long flags;
215 size_t size;
216 int abs, err;
217
218 if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
219 return -ENODEV;
220
221 vi = kzalloc(sizeof(*vi), GFP_KERNEL);
222 if (!vi)
223 return -ENOMEM;
224
225 vdev->priv = vi;
226 vi->vdev = vdev;
227 spin_lock_init(&vi->lock);
228
229 err = virtinput_init_vqs(vi);
230 if (err)
231 goto err_init_vq;
232
233 vi->idev = input_allocate_device();
234 if (!vi->idev) {
235 err = -ENOMEM;
236 goto err_input_alloc;
237 }
238 input_set_drvdata(vi->idev, vi);
239
240 size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_NAME, 0);
241 virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
242 u.string),
243 vi->name, min(size, sizeof(vi->name)));
244 size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_SERIAL, 0);
245 virtio_cread_bytes(vi->vdev, offsetof(struct virtio_input_config,
246 u.string),
247 vi->serial, min(size, sizeof(vi->serial)));
248 snprintf(vi->phys, sizeof(vi->phys),
249 "virtio%d/input0", vdev->index);
250 vi->idev->name = vi->name;
251 vi->idev->phys = vi->phys;
252 vi->idev->uniq = vi->serial;
253
254 size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_ID_DEVIDS, 0);
255 if (size >= sizeof(struct virtio_input_devids)) {
256 virtio_cread(vi->vdev, struct virtio_input_config,
257 u.ids.bustype, &vi->idev->id.bustype);
258 virtio_cread(vi->vdev, struct virtio_input_config,
259 u.ids.vendor, &vi->idev->id.vendor);
260 virtio_cread(vi->vdev, struct virtio_input_config,
261 u.ids.product, &vi->idev->id.product);
262 virtio_cread(vi->vdev, struct virtio_input_config,
263 u.ids.version, &vi->idev->id.version);
264 } else {
265 vi->idev->id.bustype = BUS_VIRTUAL;
266 }
267
268 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_PROP_BITS, 0,
269 vi->idev->propbit, INPUT_PROP_CNT);
270 size = virtinput_cfg_select(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REP);
271 if (size)
272 __set_bit(EV_REP, vi->idev->evbit);
273
274 vi->idev->dev.parent = &vdev->dev;
275 vi->idev->event = virtinput_status;
276
277 /* device -> kernel */
278 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_KEY,
279 vi->idev->keybit, KEY_CNT);
280 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_REL,
281 vi->idev->relbit, REL_CNT);
282 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_ABS,
283 vi->idev->absbit, ABS_CNT);
284 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_MSC,
285 vi->idev->mscbit, MSC_CNT);
286 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SW,
287 vi->idev->swbit, SW_CNT);
288
289 /* kernel -> device */
290 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_LED,
291 vi->idev->ledbit, LED_CNT);
292 virtinput_cfg_bits(vi, VIRTIO_INPUT_CFG_EV_BITS, EV_SND,
293 vi->idev->sndbit, SND_CNT);
294
295 if (test_bit(EV_ABS, vi->idev->evbit)) {
296 for (abs = 0; abs < ABS_CNT; abs++) {
297 if (!test_bit(abs, vi->idev->absbit))
298 continue;
299 virtinput_cfg_abs(vi, abs);
300 }
301 }
302
303 virtio_device_ready(vdev);
304 vi->ready = true;
305 err = input_register_device(vi->idev);
306 if (err)
307 goto err_input_register;
308
309 virtinput_fill_evt(vi);
310 return 0;
311
312 err_input_register:
313 spin_lock_irqsave(&vi->lock, flags);
314 vi->ready = false;
315 spin_unlock_irqrestore(&vi->lock, flags);
316 input_free_device(vi->idev);
317 err_input_alloc:
318 vdev->config->del_vqs(vdev);
319 err_init_vq:
320 kfree(vi);
321 return err;
322 }
323
virtinput_remove(struct virtio_device * vdev)324 static void virtinput_remove(struct virtio_device *vdev)
325 {
326 struct virtio_input *vi = vdev->priv;
327 void *buf;
328 unsigned long flags;
329
330 spin_lock_irqsave(&vi->lock, flags);
331 vi->ready = false;
332 spin_unlock_irqrestore(&vi->lock, flags);
333
334 input_unregister_device(vi->idev);
335 vdev->config->reset(vdev);
336 while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)
337 kfree(buf);
338 vdev->config->del_vqs(vdev);
339 kfree(vi);
340 }
341
342 #ifdef CONFIG_PM_SLEEP
virtinput_freeze(struct virtio_device * vdev)343 static int virtinput_freeze(struct virtio_device *vdev)
344 {
345 struct virtio_input *vi = vdev->priv;
346 unsigned long flags;
347
348 spin_lock_irqsave(&vi->lock, flags);
349 vi->ready = false;
350 spin_unlock_irqrestore(&vi->lock, flags);
351
352 vdev->config->del_vqs(vdev);
353 return 0;
354 }
355
virtinput_restore(struct virtio_device * vdev)356 static int virtinput_restore(struct virtio_device *vdev)
357 {
358 struct virtio_input *vi = vdev->priv;
359 int err;
360
361 err = virtinput_init_vqs(vi);
362 if (err)
363 return err;
364
365 virtio_device_ready(vdev);
366 vi->ready = true;
367 virtinput_fill_evt(vi);
368 return 0;
369 }
370 #endif
371
372 static unsigned int features[] = {
373 /* none */
374 };
375 static struct virtio_device_id id_table[] = {
376 { VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
377 { 0 },
378 };
379
380 static struct virtio_driver virtio_input_driver = {
381 .driver.name = KBUILD_MODNAME,
382 .driver.owner = THIS_MODULE,
383 .feature_table = features,
384 .feature_table_size = ARRAY_SIZE(features),
385 .id_table = id_table,
386 .probe = virtinput_probe,
387 .remove = virtinput_remove,
388 #ifdef CONFIG_PM_SLEEP
389 .freeze = virtinput_freeze,
390 .restore = virtinput_restore,
391 #endif
392 };
393
394 module_virtio_driver(virtio_input_driver);
395 MODULE_DEVICE_TABLE(virtio, id_table);
396
397 MODULE_LICENSE("GPL");
398 MODULE_DESCRIPTION("Virtio input device driver");
399 MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");
400