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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
271c8651 GH |
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 | ||
10 | struct 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 | ||
22 | static 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 | ||
31 | static 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 | */ | |
58 | static 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 | ||
89 | static 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 | ||
102 | static 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 | ||
110 | static 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 | ||
121 | static 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 | ||
155 | static 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 | ||
169 | static 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 }; | |
f7ad26ff | 174 | static const char * const names[] = { "events", "status" }; |
271c8651 GH |
175 | int err; |
176 | ||
9b2bbdb2 | 177 | err = virtio_find_vqs(vi->vdev, 2, vqs, cbs, names, NULL); |
271c8651 GH |
178 | if (err) |
179 | return err; | |
180 | vi->evt = vqs[0]; | |
181 | vi->sts = vqs[1]; | |
182 | ||
183 | return 0; | |
184 | } | |
185 | ||
186 | static 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 | ||
201 | static 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 | ||
302 | err_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); | |
307 | err_input_alloc: | |
308 | vdev->config->del_vqs(vdev); | |
309 | err_init_vq: | |
310 | kfree(vi); | |
311 | return err; | |
312 | } | |
313 | ||
314 | static void virtinput_remove(struct virtio_device *vdev) | |
315 | { | |
316 | struct virtio_input *vi = vdev->priv; | |
df4198b1 | 317 | void *buf; |
271c8651 GH |
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); | |
df4198b1 JW |
325 | vdev->config->reset(vdev); |
326 | while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL) | |
327 | kfree(buf); | |
271c8651 GH |
328 | vdev->config->del_vqs(vdev); |
329 | kfree(vi); | |
330 | } | |
331 | ||
332 | #ifdef CONFIG_PM_SLEEP | |
333 | static 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 | ||
346 | static 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 | ||
362 | static unsigned int features[] = { | |
363 | /* none */ | |
364 | }; | |
365 | static struct virtio_device_id id_table[] = { | |
366 | { VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID }, | |
367 | { 0 }, | |
368 | }; | |
369 | ||
370 | static 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 | ||
384 | module_virtio_driver(virtio_input_driver); | |
385 | MODULE_DEVICE_TABLE(virtio, id_table); | |
386 | ||
387 | MODULE_LICENSE("GPL"); | |
388 | MODULE_DESCRIPTION("Virtio input device driver"); | |
389 | MODULE_AUTHOR("Gerd Hoffmann <kraxel@redhat.com>"); |