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