xref: /openbmc/linux/drivers/hid/hid-sensor-hub.c (revision 0d456bad)
1 /*
2  * HID Sensors Driver
3  * Copyright (c) 2012, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  */
19 #include <linux/device.h>
20 #include <linux/hid.h>
21 #include <linux/usb.h>
22 #include "usbhid/usbhid.h"
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/mfd/core.h>
26 #include <linux/list.h>
27 #include <linux/hid-sensor-ids.h>
28 #include <linux/hid-sensor-hub.h>
29 #include "hid-ids.h"
30 
31 /**
32  * struct sensor_hub_pending - Synchronous read pending information
33  * @status:		Pending status true/false.
34  * @ready:		Completion synchronization data.
35  * @usage_id:		Usage id for physical device, E.g. Gyro usage id.
36  * @attr_usage_id:	Usage Id of a field, E.g. X-AXIS for a gyro.
37  * @raw_size:		Response size for a read request.
38  * @raw_data:		Place holder for received response.
39  */
40 struct sensor_hub_pending {
41 	bool status;
42 	struct completion ready;
43 	u32 usage_id;
44 	u32 attr_usage_id;
45 	int raw_size;
46 	u8  *raw_data;
47 };
48 
49 /**
50  * struct sensor_hub_data - Hold a instance data for a HID hub device
51  * @hsdev:		Stored hid instance for current hub device.
52  * @mutex:		Mutex to serialize synchronous request.
53  * @lock:		Spin lock to protect pending request structure.
54  * @pending:		Holds information of pending sync read request.
55  * @dyn_callback_list:	Holds callback function
56  * @dyn_callback_lock:	spin lock to protect callback list
57  * @hid_sensor_hub_client_devs:	Stores all MFD cells for a hub instance.
58  * @hid_sensor_client_cnt: Number of MFD cells, (no of sensors attached).
59  */
60 struct sensor_hub_data {
61 	struct hid_sensor_hub_device *hsdev;
62 	struct mutex mutex;
63 	spinlock_t lock;
64 	struct sensor_hub_pending pending;
65 	struct list_head dyn_callback_list;
66 	spinlock_t dyn_callback_lock;
67 	struct mfd_cell *hid_sensor_hub_client_devs;
68 	int hid_sensor_client_cnt;
69 };
70 
71 /**
72  * struct hid_sensor_hub_callbacks_list - Stores callback list
73  * @list:		list head.
74  * @usage_id:		usage id for a physical device.
75  * @usage_callback:	Stores registered callback functions.
76  * @priv:		Private data for a physical device.
77  */
78 struct hid_sensor_hub_callbacks_list {
79 	struct list_head list;
80 	u32 usage_id;
81 	struct hid_sensor_hub_callbacks *usage_callback;
82 	void *priv;
83 };
84 
85 static struct hid_report *sensor_hub_report(int id, struct hid_device *hdev,
86 						int dir)
87 {
88 	struct hid_report *report;
89 
90 	list_for_each_entry(report, &hdev->report_enum[dir].report_list, list) {
91 		if (report->id == id)
92 			return report;
93 	}
94 	hid_warn(hdev, "No report with id 0x%x found\n", id);
95 
96 	return NULL;
97 }
98 
99 static int sensor_hub_get_physical_device_count(
100 				struct hid_report_enum *report_enum)
101 {
102 	struct hid_report *report;
103 	struct hid_field *field;
104 	int cnt = 0;
105 
106 	list_for_each_entry(report, &report_enum->report_list, list) {
107 		field = report->field[0];
108 		if (report->maxfield && field &&
109 					field->physical)
110 			cnt++;
111 	}
112 
113 	return cnt;
114 }
115 
116 static void sensor_hub_fill_attr_info(
117 		struct hid_sensor_hub_attribute_info *info,
118 		s32 index, s32 report_id, s32 units, s32 unit_expo, s32 size)
119 {
120 	info->index = index;
121 	info->report_id = report_id;
122 	info->units = units;
123 	info->unit_expo = unit_expo;
124 	info->size = size/8;
125 }
126 
127 static struct hid_sensor_hub_callbacks *sensor_hub_get_callback(
128 					struct hid_device *hdev,
129 					u32 usage_id, void **priv)
130 {
131 	struct hid_sensor_hub_callbacks_list *callback;
132 	struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
133 
134 	spin_lock(&pdata->dyn_callback_lock);
135 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
136 		if (callback->usage_id == usage_id) {
137 			*priv = callback->priv;
138 			spin_unlock(&pdata->dyn_callback_lock);
139 			return callback->usage_callback;
140 		}
141 	spin_unlock(&pdata->dyn_callback_lock);
142 
143 	return NULL;
144 }
145 
146 int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
147 			u32 usage_id,
148 			struct hid_sensor_hub_callbacks *usage_callback)
149 {
150 	struct hid_sensor_hub_callbacks_list *callback;
151 	struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
152 
153 	spin_lock(&pdata->dyn_callback_lock);
154 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
155 		if (callback->usage_id == usage_id) {
156 			spin_unlock(&pdata->dyn_callback_lock);
157 			return -EINVAL;
158 		}
159 	callback = kzalloc(sizeof(*callback), GFP_ATOMIC);
160 	if (!callback) {
161 		spin_unlock(&pdata->dyn_callback_lock);
162 		return -ENOMEM;
163 	}
164 	callback->usage_callback = usage_callback;
165 	callback->usage_id = usage_id;
166 	callback->priv = NULL;
167 	list_add_tail(&callback->list, &pdata->dyn_callback_list);
168 	spin_unlock(&pdata->dyn_callback_lock);
169 
170 	return 0;
171 }
172 EXPORT_SYMBOL_GPL(sensor_hub_register_callback);
173 
174 int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
175 				u32 usage_id)
176 {
177 	struct hid_sensor_hub_callbacks_list *callback;
178 	struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
179 
180 	spin_lock(&pdata->dyn_callback_lock);
181 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
182 		if (callback->usage_id == usage_id) {
183 			list_del(&callback->list);
184 			kfree(callback);
185 			break;
186 		}
187 	spin_unlock(&pdata->dyn_callback_lock);
188 
189 	return 0;
190 }
191 EXPORT_SYMBOL_GPL(sensor_hub_remove_callback);
192 
193 int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
194 				u32 field_index, s32 value)
195 {
196 	struct hid_report *report;
197 	struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);
198 	int ret = 0;
199 
200 	mutex_lock(&data->mutex);
201 	report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
202 	if (!report || (field_index >=  report->maxfield)) {
203 		ret = -EINVAL;
204 		goto done_proc;
205 	}
206 	hid_set_field(report->field[field_index], 0, value);
207 	usbhid_submit_report(hsdev->hdev, report, USB_DIR_OUT);
208 	usbhid_wait_io(hsdev->hdev);
209 
210 done_proc:
211 	mutex_unlock(&data->mutex);
212 
213 	return ret;
214 }
215 EXPORT_SYMBOL_GPL(sensor_hub_set_feature);
216 
217 int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
218 				u32 field_index, s32 *value)
219 {
220 	struct hid_report *report;
221 	struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);
222 	int ret = 0;
223 
224 	mutex_lock(&data->mutex);
225 	report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
226 	if (!report || (field_index >=  report->maxfield)) {
227 		ret = -EINVAL;
228 		goto done_proc;
229 	}
230 	usbhid_submit_report(hsdev->hdev, report, USB_DIR_IN);
231 	usbhid_wait_io(hsdev->hdev);
232 	*value = report->field[field_index]->value[0];
233 
234 done_proc:
235 	mutex_unlock(&data->mutex);
236 
237 	return ret;
238 }
239 EXPORT_SYMBOL_GPL(sensor_hub_get_feature);
240 
241 
242 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
243 					u32 usage_id,
244 					u32 attr_usage_id, u32 report_id)
245 {
246 	struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);
247 	unsigned long flags;
248 	struct hid_report *report;
249 	int ret_val = 0;
250 
251 	mutex_lock(&data->mutex);
252 	memset(&data->pending, 0, sizeof(data->pending));
253 	init_completion(&data->pending.ready);
254 	data->pending.usage_id = usage_id;
255 	data->pending.attr_usage_id = attr_usage_id;
256 	data->pending.raw_size = 0;
257 
258 	spin_lock_irqsave(&data->lock, flags);
259 	data->pending.status = true;
260 	report = sensor_hub_report(report_id, hsdev->hdev, HID_INPUT_REPORT);
261 	if (!report) {
262 		spin_unlock_irqrestore(&data->lock, flags);
263 		goto err_free;
264 	}
265 	usbhid_submit_report(hsdev->hdev, report, USB_DIR_IN);
266 	spin_unlock_irqrestore(&data->lock, flags);
267 	wait_for_completion_interruptible_timeout(&data->pending.ready, HZ*5);
268 	switch (data->pending.raw_size) {
269 	case 1:
270 		ret_val = *(u8 *)data->pending.raw_data;
271 		break;
272 	case 2:
273 		ret_val = *(u16 *)data->pending.raw_data;
274 		break;
275 	case 4:
276 		ret_val = *(u32 *)data->pending.raw_data;
277 		break;
278 	default:
279 		ret_val = 0;
280 	}
281 	kfree(data->pending.raw_data);
282 
283 err_free:
284 	data->pending.status = false;
285 	mutex_unlock(&data->mutex);
286 
287 	return ret_val;
288 }
289 EXPORT_SYMBOL_GPL(sensor_hub_input_attr_get_raw_value);
290 
291 int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
292 				u8 type,
293 				u32 usage_id,
294 				u32 attr_usage_id,
295 				struct hid_sensor_hub_attribute_info *info)
296 {
297 	int ret = -1;
298 	int i, j;
299 	int collection_index = -1;
300 	struct hid_report *report;
301 	struct hid_field *field;
302 	struct hid_report_enum *report_enum;
303 	struct hid_device *hdev = hsdev->hdev;
304 
305 	/* Initialize with defaults */
306 	info->usage_id = usage_id;
307 	info->attrib_id =  attr_usage_id;
308 	info->report_id = -1;
309 	info->index = -1;
310 	info->units = -1;
311 	info->unit_expo = -1;
312 
313 	for (i = 0; i < hdev->maxcollection; ++i) {
314 		struct hid_collection *collection = &hdev->collection[i];
315 		if (usage_id == collection->usage) {
316 			collection_index = i;
317 			break;
318 		}
319 	}
320 	if (collection_index == -1)
321 		goto err_ret;
322 
323 	report_enum = &hdev->report_enum[type];
324 	list_for_each_entry(report, &report_enum->report_list, list) {
325 		for (i = 0; i < report->maxfield; ++i) {
326 			field = report->field[i];
327 			if (field->physical == usage_id &&
328 				field->logical == attr_usage_id) {
329 				sensor_hub_fill_attr_info(info, i, report->id,
330 					field->unit, field->unit_exponent,
331 					field->report_size);
332 				ret = 0;
333 			} else {
334 				for (j = 0; j < field->maxusage; ++j) {
335 					if (field->usage[j].hid ==
336 					attr_usage_id &&
337 					field->usage[j].collection_index ==
338 					collection_index)  {
339 						sensor_hub_fill_attr_info(info,
340 							i, report->id,
341 							field->unit,
342 							field->unit_exponent,
343 							field->report_size);
344 						ret = 0;
345 						break;
346 					}
347 				}
348 			}
349 			if (ret == 0)
350 				break;
351 		}
352 	}
353 
354 err_ret:
355 	return ret;
356 }
357 EXPORT_SYMBOL_GPL(sensor_hub_input_get_attribute_info);
358 
359 #ifdef CONFIG_PM
360 static int sensor_hub_suspend(struct hid_device *hdev, pm_message_t message)
361 {
362 	struct sensor_hub_data *pdata =  hid_get_drvdata(hdev);
363 	struct hid_sensor_hub_callbacks_list *callback;
364 
365 	hid_dbg(hdev, " sensor_hub_suspend\n");
366 	spin_lock(&pdata->dyn_callback_lock);
367 	list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
368 		if (callback->usage_callback->suspend)
369 			callback->usage_callback->suspend(
370 					pdata->hsdev, callback->priv);
371 	}
372 	spin_unlock(&pdata->dyn_callback_lock);
373 
374 	return 0;
375 }
376 
377 static int sensor_hub_resume(struct hid_device *hdev)
378 {
379 	struct sensor_hub_data *pdata =  hid_get_drvdata(hdev);
380 	struct hid_sensor_hub_callbacks_list *callback;
381 
382 	hid_dbg(hdev, " sensor_hub_resume\n");
383 	spin_lock(&pdata->dyn_callback_lock);
384 	list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
385 		if (callback->usage_callback->resume)
386 			callback->usage_callback->resume(
387 					pdata->hsdev, callback->priv);
388 	}
389 	spin_unlock(&pdata->dyn_callback_lock);
390 
391 	return 0;
392 }
393 
394 static int sensor_hub_reset_resume(struct hid_device *hdev)
395 {
396 	return 0;
397 }
398 #endif
399 /*
400  * Handle raw report as sent by device
401  */
402 static int sensor_hub_raw_event(struct hid_device *hdev,
403 		struct hid_report *report, u8 *raw_data, int size)
404 {
405 	int i;
406 	u8 *ptr;
407 	int sz;
408 	struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
409 	unsigned long flags;
410 	struct hid_sensor_hub_callbacks *callback = NULL;
411 	struct hid_collection *collection = NULL;
412 	void *priv = NULL;
413 
414 	hid_dbg(hdev, "sensor_hub_raw_event report id:0x%x size:%d type:%d\n",
415 			 report->id, size, report->type);
416 	hid_dbg(hdev, "maxfield:%d\n", report->maxfield);
417 	if (report->type != HID_INPUT_REPORT)
418 		return 1;
419 
420 	ptr = raw_data;
421 	ptr++; /*Skip report id*/
422 
423 	spin_lock_irqsave(&pdata->lock, flags);
424 
425 	for (i = 0; i < report->maxfield; ++i) {
426 
427 		hid_dbg(hdev, "%d collection_index:%x hid:%x sz:%x\n",
428 				i, report->field[i]->usage->collection_index,
429 				report->field[i]->usage->hid,
430 				report->field[i]->report_size/8);
431 
432 		sz = report->field[i]->report_size/8;
433 		if (pdata->pending.status && pdata->pending.attr_usage_id ==
434 				report->field[i]->usage->hid) {
435 			hid_dbg(hdev, "data was pending ...\n");
436 			pdata->pending.raw_data = kmalloc(sz, GFP_ATOMIC);
437 			if (pdata->pending.raw_data) {
438 				memcpy(pdata->pending.raw_data, ptr, sz);
439 				pdata->pending.raw_size  = sz;
440 			} else
441 				pdata->pending.raw_size = 0;
442 			complete(&pdata->pending.ready);
443 		}
444 		collection = &hdev->collection[
445 				report->field[i]->usage->collection_index];
446 		hid_dbg(hdev, "collection->usage %x\n",
447 					collection->usage);
448 		callback = sensor_hub_get_callback(pdata->hsdev->hdev,
449 						report->field[i]->physical,
450 							&priv);
451 		if (callback && callback->capture_sample) {
452 			if (report->field[i]->logical)
453 				callback->capture_sample(pdata->hsdev,
454 					report->field[i]->logical, sz, ptr,
455 					callback->pdev);
456 			else
457 				callback->capture_sample(pdata->hsdev,
458 					report->field[i]->usage->hid, sz, ptr,
459 					callback->pdev);
460 		}
461 		ptr += sz;
462 	}
463 	if (callback && collection && callback->send_event)
464 		callback->send_event(pdata->hsdev, collection->usage,
465 				callback->pdev);
466 	spin_unlock_irqrestore(&pdata->lock, flags);
467 
468 	return 1;
469 }
470 
471 static int sensor_hub_probe(struct hid_device *hdev,
472 				const struct hid_device_id *id)
473 {
474 	int ret;
475 	struct sensor_hub_data *sd;
476 	int i;
477 	char *name;
478 	struct hid_report *report;
479 	struct hid_report_enum *report_enum;
480 	struct hid_field *field;
481 	int dev_cnt;
482 
483 	sd = kzalloc(sizeof(struct sensor_hub_data), GFP_KERNEL);
484 	if (!sd) {
485 		hid_err(hdev, "cannot allocate Sensor data\n");
486 		return -ENOMEM;
487 	}
488 	sd->hsdev = kzalloc(sizeof(struct hid_sensor_hub_device), GFP_KERNEL);
489 	if (!sd->hsdev) {
490 		hid_err(hdev, "cannot allocate hid_sensor_hub_device\n");
491 		ret = -ENOMEM;
492 		goto err_free_hub;
493 	}
494 	hid_set_drvdata(hdev, sd);
495 	sd->hsdev->hdev = hdev;
496 	sd->hsdev->vendor_id = hdev->vendor;
497 	sd->hsdev->product_id = hdev->product;
498 	spin_lock_init(&sd->lock);
499 	spin_lock_init(&sd->dyn_callback_lock);
500 	mutex_init(&sd->mutex);
501 	ret = hid_parse(hdev);
502 	if (ret) {
503 		hid_err(hdev, "parse failed\n");
504 		goto err_free;
505 	}
506 	INIT_LIST_HEAD(&hdev->inputs);
507 
508 	ret = hid_hw_start(hdev, 0);
509 	if (ret) {
510 		hid_err(hdev, "hw start failed\n");
511 		goto err_free;
512 	}
513 	ret = hid_hw_open(hdev);
514 	if (ret) {
515 		hid_err(hdev, "failed to open input interrupt pipe\n");
516 		goto err_stop_hw;
517 	}
518 
519 	INIT_LIST_HEAD(&sd->dyn_callback_list);
520 	sd->hid_sensor_client_cnt = 0;
521 	report_enum = &hdev->report_enum[HID_INPUT_REPORT];
522 
523 	dev_cnt = sensor_hub_get_physical_device_count(report_enum);
524 	if (dev_cnt > HID_MAX_PHY_DEVICES) {
525 		hid_err(hdev, "Invalid Physical device count\n");
526 		ret = -EINVAL;
527 		goto err_close;
528 	}
529 	sd->hid_sensor_hub_client_devs = kzalloc(dev_cnt *
530 						sizeof(struct mfd_cell),
531 						GFP_KERNEL);
532 	if (sd->hid_sensor_hub_client_devs == NULL) {
533 		hid_err(hdev, "Failed to allocate memory for mfd cells\n");
534 			ret = -ENOMEM;
535 			goto err_close;
536 	}
537 	list_for_each_entry(report, &report_enum->report_list, list) {
538 		hid_dbg(hdev, "Report id:%x\n", report->id);
539 		field = report->field[0];
540 		if (report->maxfield && field &&
541 					field->physical) {
542 			name = kasprintf(GFP_KERNEL, "HID-SENSOR-%x",
543 						field->physical);
544 			if (name  == NULL) {
545 				hid_err(hdev, "Failed MFD device name\n");
546 					ret = -ENOMEM;
547 					goto err_free_names;
548 			}
549 			sd->hid_sensor_hub_client_devs[
550 				sd->hid_sensor_client_cnt].name = name;
551 			sd->hid_sensor_hub_client_devs[
552 				sd->hid_sensor_client_cnt].platform_data =
553 						sd->hsdev;
554 			sd->hid_sensor_hub_client_devs[
555 				sd->hid_sensor_client_cnt].pdata_size =
556 						sizeof(*sd->hsdev);
557 			hid_dbg(hdev, "Adding %s:%p\n", name, sd);
558 			sd->hid_sensor_client_cnt++;
559 		}
560 	}
561 	ret = mfd_add_devices(&hdev->dev, 0, sd->hid_sensor_hub_client_devs,
562 		sd->hid_sensor_client_cnt, NULL, 0, NULL);
563 	if (ret < 0)
564 		goto err_free_names;
565 
566 	return ret;
567 
568 err_free_names:
569 	for (i = 0; i < sd->hid_sensor_client_cnt ; ++i)
570 		kfree(sd->hid_sensor_hub_client_devs[i].name);
571 	kfree(sd->hid_sensor_hub_client_devs);
572 err_close:
573 	hid_hw_close(hdev);
574 err_stop_hw:
575 	hid_hw_stop(hdev);
576 err_free:
577 	kfree(sd->hsdev);
578 err_free_hub:
579 	kfree(sd);
580 
581 	return ret;
582 }
583 
584 static void sensor_hub_remove(struct hid_device *hdev)
585 {
586 	struct sensor_hub_data *data = hid_get_drvdata(hdev);
587 	unsigned long flags;
588 	int i;
589 
590 	hid_dbg(hdev, " hardware removed\n");
591 	hid_hw_close(hdev);
592 	hid_hw_stop(hdev);
593 	spin_lock_irqsave(&data->lock, flags);
594 	if (data->pending.status)
595 		complete(&data->pending.ready);
596 	spin_unlock_irqrestore(&data->lock, flags);
597 	mfd_remove_devices(&hdev->dev);
598 	for (i = 0; i < data->hid_sensor_client_cnt ; ++i)
599 		kfree(data->hid_sensor_hub_client_devs[i].name);
600 	kfree(data->hid_sensor_hub_client_devs);
601 	hid_set_drvdata(hdev, NULL);
602 	mutex_destroy(&data->mutex);
603 	kfree(data->hsdev);
604 	kfree(data);
605 }
606 
607 static const struct hid_device_id sensor_hub_devices[] = {
608 	{ HID_DEVICE(BUS_USB, HID_GROUP_SENSOR_HUB, HID_ANY_ID, HID_ANY_ID) },
609 	{ }
610 };
611 MODULE_DEVICE_TABLE(hid, sensor_hub_devices);
612 
613 static const struct hid_usage_id sensor_hub_grabbed_usages[] = {
614 	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
615 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
616 };
617 
618 static struct hid_driver sensor_hub_driver = {
619 	.name = "hid-sensor-hub",
620 	.id_table = sensor_hub_devices,
621 	.probe = sensor_hub_probe,
622 	.remove = sensor_hub_remove,
623 	.raw_event = sensor_hub_raw_event,
624 #ifdef CONFIG_PM
625 	.suspend = sensor_hub_suspend,
626 	.resume =  sensor_hub_resume,
627 	.reset_resume =  sensor_hub_reset_resume,
628 #endif
629 };
630 
631 static int __init sensor_hub_init(void)
632 {
633 	return hid_register_driver(&sensor_hub_driver);
634 }
635 
636 static void __exit sensor_hub_exit(void)
637 {
638 	hid_unregister_driver(&sensor_hub_driver);
639 }
640 
641 module_init(sensor_hub_init);
642 module_exit(sensor_hub_exit);
643 
644 MODULE_DESCRIPTION("HID Sensor Hub driver");
645 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@intel.com>");
646 MODULE_LICENSE("GPL");
647