virtio_input.c 10 KB

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