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
9 struct 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
virtinput_queue_evtbuf(struct virtio_input * vi,struct virtio_input_event * evtbuf)21 static 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
virtinput_recv_events(struct virtqueue * vq)30 static 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 */
virtinput_send_status(struct virtio_input * vi,u16 type,u16 code,s32 value)57 static 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
virtinput_recv_status(struct virtqueue * vq)88 static 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
virtinput_status(struct input_dev * idev,unsigned int type,unsigned int code,int value)101 static 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
virtinput_cfg_select(struct virtio_input * vi,u8 select,u8 subsel)109 static 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
virtinput_cfg_bits(struct virtio_input * vi,int select,int subsel,unsigned long * bits,unsigned int bitcount)120 static 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
virtinput_cfg_abs(struct virtio_input * vi,int abs)154 static 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
virtinput_init_vqs(struct virtio_input * vi)168 static 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 * const names[] = { "events", "status" };
174 int err;
175
176 err = virtio_find_vqs(vi->vdev, 2, vqs, cbs, names, NULL);
177 if (err)
178 return err;
179 vi->evt = vqs[0];
180 vi->sts = vqs[1];
181
182 return 0;
183 }
184
virtinput_fill_evt(struct virtio_input * vi)185 static 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
virtinput_probe(struct virtio_device * vdev)200 static 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
301 err_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);
306 err_input_alloc:
307 vdev->config->del_vqs(vdev);
308 err_init_vq:
309 kfree(vi);
310 return err;
311 }
312
virtinput_remove(struct virtio_device * vdev)313 static 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
virtinput_freeze(struct virtio_device * vdev)332 static 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
virtinput_restore(struct virtio_device * vdev)345 static 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
361 static unsigned int features[] = {
362 /* none */
363 };
364 static struct virtio_device_id id_table[] = {
365 { VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
366 { 0 },
367 };
368
369 static 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
383 module_virtio_driver(virtio_input_driver);
384 MODULE_DEVICE_TABLE(virtio, id_table);
385
386 MODULE_LICENSE("GPL");
387 MODULE_DESCRIPTION("Virtio input device driver");
388 MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>");
389