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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_hid.c -- USB HID function driver
4 *
5 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/hid.h>
11#include <linux/idr.h>
12#include <linux/cdev.h>
13#include <linux/mutex.h>
14#include <linux/poll.h>
15#include <linux/uaccess.h>
16#include <linux/wait.h>
17#include <linux/sched.h>
18#include <linux/workqueue.h>
19#include <linux/usb/func_utils.h>
20#include <linux/usb/g_hid.h>
21#include <uapi/linux/usb/g_hid.h>
22
23#include "u_hid.h"
24
25#define HIDG_MINORS 4
26
27/*
28 * Most operating systems seem to allow for 5000ms timeout, we will allow
29 * userspace half that time to respond before we return an empty report.
30 */
31#define GET_REPORT_TIMEOUT_MS 2500
32
33static int major, minors;
34
35static const struct class hidg_class = {
36 .name = "hidg",
37};
38
39static DEFINE_IDA(hidg_ida);
40static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
41
42struct report_entry {
43 struct usb_hidg_report report_data;
44 struct list_head node;
45};
46
47/*-------------------------------------------------------------------------*/
48/* HID gadget struct */
49
50struct f_hidg_req_list {
51 struct usb_request *req;
52 unsigned int pos;
53 struct list_head list;
54};
55
56struct f_hidg {
57 /* configuration */
58 unsigned char bInterfaceSubClass;
59 unsigned char bInterfaceProtocol;
60 unsigned char protocol;
61 unsigned char idle;
62 unsigned short report_desc_length;
63 char *report_desc;
64 unsigned short report_length;
65 /*
66 * use_out_ep - if true, the OUT Endpoint (interrupt out method)
67 * will be used to receive reports from the host
68 * using functions with the "intout" suffix.
69 * Otherwise, the OUT Endpoint will not be configured
70 * and the SETUP/SET_REPORT method ("ssreport" suffix)
71 * will be used to receive reports.
72 */
73 bool use_out_ep;
74
75 /* recv report */
76 spinlock_t read_spinlock;
77 wait_queue_head_t read_queue;
78 /* recv report - interrupt out only (use_out_ep == 1) */
79 struct list_head completed_out_req;
80 unsigned int qlen;
81 /* recv report - setup set_report only (use_out_ep == 0) */
82 char *set_report_buf;
83 unsigned int set_report_length;
84
85 /* send report */
86 spinlock_t write_spinlock;
87 bool write_pending;
88 wait_queue_head_t write_queue;
89 struct usb_request *req;
90
91 /* get report */
92 struct usb_request *get_req;
93 struct usb_hidg_report get_report;
94 bool get_report_returned;
95 int get_report_req_report_id;
96 int get_report_req_report_length;
97 spinlock_t get_report_spinlock;
98 wait_queue_head_t get_queue; /* Waiting for userspace response */
99 wait_queue_head_t get_id_queue; /* Get ID came in */
100 struct work_struct work;
101 struct workqueue_struct *workqueue;
102 struct list_head report_list;
103
104 struct device dev;
105 struct cdev cdev;
106 struct usb_function func;
107
108 struct usb_ep *in_ep;
109 struct usb_ep *out_ep;
110};
111
112static inline struct f_hidg *func_to_hidg(struct usb_function *f)
113{
114 return container_of(f, struct f_hidg, func);
115}
116
117static void hidg_release(struct device *dev)
118{
119 struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
120
121 kfree(hidg->report_desc);
122 kfree(hidg->set_report_buf);
123 kfree(hidg);
124}
125
126/*-------------------------------------------------------------------------*/
127/* Static descriptors */
128
129static struct usb_interface_descriptor hidg_interface_desc = {
130 .bLength = sizeof hidg_interface_desc,
131 .bDescriptorType = USB_DT_INTERFACE,
132 /* .bInterfaceNumber = DYNAMIC */
133 .bAlternateSetting = 0,
134 /* .bNumEndpoints = DYNAMIC (depends on use_out_ep) */
135 .bInterfaceClass = USB_CLASS_HID,
136 /* .bInterfaceSubClass = DYNAMIC */
137 /* .bInterfaceProtocol = DYNAMIC */
138 /* .iInterface = DYNAMIC */
139};
140
141static struct hid_descriptor hidg_desc = {
142 .bLength = sizeof hidg_desc,
143 .bDescriptorType = HID_DT_HID,
144 .bcdHID = cpu_to_le16(0x0101),
145 .bCountryCode = 0x00,
146 .bNumDescriptors = 0x1,
147 /*.desc[0].bDescriptorType = DYNAMIC */
148 /*.desc[0].wDescriptorLenght = DYNAMIC */
149};
150
151/* Super-Speed Support */
152
153static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
154 .bLength = USB_DT_ENDPOINT_SIZE,
155 .bDescriptorType = USB_DT_ENDPOINT,
156 .bEndpointAddress = USB_DIR_IN,
157 .bmAttributes = USB_ENDPOINT_XFER_INT,
158 /*.wMaxPacketSize = DYNAMIC */
159 .bInterval = 4, /* FIXME: Add this field in the
160 * HID gadget configuration?
161 * (struct hidg_func_descriptor)
162 */
163};
164
165static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
166 .bLength = sizeof(hidg_ss_in_comp_desc),
167 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
168
169 /* .bMaxBurst = 0, */
170 /* .bmAttributes = 0, */
171 /* .wBytesPerInterval = DYNAMIC */
172};
173
174static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
175 .bLength = USB_DT_ENDPOINT_SIZE,
176 .bDescriptorType = USB_DT_ENDPOINT,
177 .bEndpointAddress = USB_DIR_OUT,
178 .bmAttributes = USB_ENDPOINT_XFER_INT,
179 /*.wMaxPacketSize = DYNAMIC */
180 .bInterval = 4, /* FIXME: Add this field in the
181 * HID gadget configuration?
182 * (struct hidg_func_descriptor)
183 */
184};
185
186static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
187 .bLength = sizeof(hidg_ss_out_comp_desc),
188 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
189
190 /* .bMaxBurst = 0, */
191 /* .bmAttributes = 0, */
192 /* .wBytesPerInterval = DYNAMIC */
193};
194
195static struct usb_descriptor_header *hidg_ss_descriptors_intout[] = {
196 (struct usb_descriptor_header *)&hidg_interface_desc,
197 (struct usb_descriptor_header *)&hidg_desc,
198 (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
199 (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
200 (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
201 (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
202 NULL,
203};
204
205static struct usb_descriptor_header *hidg_ss_descriptors_ssreport[] = {
206 (struct usb_descriptor_header *)&hidg_interface_desc,
207 (struct usb_descriptor_header *)&hidg_desc,
208 (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
209 (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
210 NULL,
211};
212
213/* High-Speed Support */
214
215static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
216 .bLength = USB_DT_ENDPOINT_SIZE,
217 .bDescriptorType = USB_DT_ENDPOINT,
218 .bEndpointAddress = USB_DIR_IN,
219 .bmAttributes = USB_ENDPOINT_XFER_INT,
220 /*.wMaxPacketSize = DYNAMIC */
221 .bInterval = 4, /* FIXME: Add this field in the
222 * HID gadget configuration?
223 * (struct hidg_func_descriptor)
224 */
225};
226
227static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
228 .bLength = USB_DT_ENDPOINT_SIZE,
229 .bDescriptorType = USB_DT_ENDPOINT,
230 .bEndpointAddress = USB_DIR_OUT,
231 .bmAttributes = USB_ENDPOINT_XFER_INT,
232 /*.wMaxPacketSize = DYNAMIC */
233 .bInterval = 4, /* FIXME: Add this field in the
234 * HID gadget configuration?
235 * (struct hidg_func_descriptor)
236 */
237};
238
239static struct usb_descriptor_header *hidg_hs_descriptors_intout[] = {
240 (struct usb_descriptor_header *)&hidg_interface_desc,
241 (struct usb_descriptor_header *)&hidg_desc,
242 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
243 (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
244 NULL,
245};
246
247static struct usb_descriptor_header *hidg_hs_descriptors_ssreport[] = {
248 (struct usb_descriptor_header *)&hidg_interface_desc,
249 (struct usb_descriptor_header *)&hidg_desc,
250 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
251 NULL,
252};
253
254/* Full-Speed Support */
255
256static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
257 .bLength = USB_DT_ENDPOINT_SIZE,
258 .bDescriptorType = USB_DT_ENDPOINT,
259 .bEndpointAddress = USB_DIR_IN,
260 .bmAttributes = USB_ENDPOINT_XFER_INT,
261 /*.wMaxPacketSize = DYNAMIC */
262 .bInterval = 10, /* FIXME: Add this field in the
263 * HID gadget configuration?
264 * (struct hidg_func_descriptor)
265 */
266};
267
268static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
269 .bLength = USB_DT_ENDPOINT_SIZE,
270 .bDescriptorType = USB_DT_ENDPOINT,
271 .bEndpointAddress = USB_DIR_OUT,
272 .bmAttributes = USB_ENDPOINT_XFER_INT,
273 /*.wMaxPacketSize = DYNAMIC */
274 .bInterval = 10, /* FIXME: Add this field in the
275 * HID gadget configuration?
276 * (struct hidg_func_descriptor)
277 */
278};
279
280static struct usb_descriptor_header *hidg_fs_descriptors_intout[] = {
281 (struct usb_descriptor_header *)&hidg_interface_desc,
282 (struct usb_descriptor_header *)&hidg_desc,
283 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
284 (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
285 NULL,
286};
287
288static struct usb_descriptor_header *hidg_fs_descriptors_ssreport[] = {
289 (struct usb_descriptor_header *)&hidg_interface_desc,
290 (struct usb_descriptor_header *)&hidg_desc,
291 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
292 NULL,
293};
294
295/*-------------------------------------------------------------------------*/
296/* Strings */
297
298#define CT_FUNC_HID_IDX 0
299
300static struct usb_string ct_func_string_defs[] = {
301 [CT_FUNC_HID_IDX].s = "HID Interface",
302 {}, /* end of list */
303};
304
305static struct usb_gadget_strings ct_func_string_table = {
306 .language = 0x0409, /* en-US */
307 .strings = ct_func_string_defs,
308};
309
310static struct usb_gadget_strings *ct_func_strings[] = {
311 &ct_func_string_table,
312 NULL,
313};
314
315/*-------------------------------------------------------------------------*/
316/* Char Device */
317
318static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer,
319 size_t count, loff_t *ptr)
320{
321 struct f_hidg *hidg = file->private_data;
322 struct f_hidg_req_list *list;
323 struct usb_request *req;
324 unsigned long flags;
325 int ret;
326
327 if (!count)
328 return 0;
329
330 spin_lock_irqsave(&hidg->read_spinlock, flags);
331
332#define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req))
333
334 /* wait for at least one buffer to complete */
335 while (!READ_COND_INTOUT) {
336 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
337 if (file->f_flags & O_NONBLOCK)
338 return -EAGAIN;
339
340 if (wait_event_interruptible(hidg->read_queue, READ_COND_INTOUT))
341 return -ERESTARTSYS;
342
343 spin_lock_irqsave(&hidg->read_spinlock, flags);
344 }
345
346 /* pick the first one */
347 list = list_first_entry(&hidg->completed_out_req,
348 struct f_hidg_req_list, list);
349
350 /*
351 * Remove this from list to protect it from beign free()
352 * while host disables our function
353 */
354 list_del(&list->list);
355
356 req = list->req;
357 count = min_t(unsigned int, count, req->actual - list->pos);
358 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
359
360 /* copy to user outside spinlock */
361 count -= copy_to_user(buffer, req->buf + list->pos, count);
362 list->pos += count;
363
364 /*
365 * if this request is completely handled and transfered to
366 * userspace, remove its entry from the list and requeue it
367 * again. Otherwise, we will revisit it again upon the next
368 * call, taking into account its current read position.
369 */
370 if (list->pos == req->actual) {
371 kfree(list);
372
373 req->length = hidg->report_length;
374 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
375 if (ret < 0) {
376 free_ep_req(hidg->out_ep, req);
377 return ret;
378 }
379 } else {
380 spin_lock_irqsave(&hidg->read_spinlock, flags);
381 list_add(&list->list, &hidg->completed_out_req);
382 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
383
384 wake_up(&hidg->read_queue);
385 }
386
387 return count;
388}
389
390#define READ_COND_SSREPORT (hidg->set_report_buf != NULL)
391
392static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer,
393 size_t count, loff_t *ptr)
394{
395 struct f_hidg *hidg = file->private_data;
396 char *tmp_buf = NULL;
397 unsigned long flags;
398
399 if (!count)
400 return 0;
401
402 spin_lock_irqsave(&hidg->read_spinlock, flags);
403
404 while (!READ_COND_SSREPORT) {
405 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
406 if (file->f_flags & O_NONBLOCK)
407 return -EAGAIN;
408
409 if (wait_event_interruptible(hidg->read_queue, READ_COND_SSREPORT))
410 return -ERESTARTSYS;
411
412 spin_lock_irqsave(&hidg->read_spinlock, flags);
413 }
414
415 count = min_t(unsigned int, count, hidg->set_report_length);
416 tmp_buf = hidg->set_report_buf;
417 hidg->set_report_buf = NULL;
418
419 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
420
421 if (tmp_buf != NULL) {
422 count -= copy_to_user(buffer, tmp_buf, count);
423 kfree(tmp_buf);
424 } else {
425 count = -ENOMEM;
426 }
427
428 wake_up(&hidg->read_queue);
429
430 return count;
431}
432
433static ssize_t f_hidg_read(struct file *file, char __user *buffer,
434 size_t count, loff_t *ptr)
435{
436 struct f_hidg *hidg = file->private_data;
437
438 if (hidg->use_out_ep)
439 return f_hidg_intout_read(file, buffer, count, ptr);
440 else
441 return f_hidg_ssreport_read(file, buffer, count, ptr);
442}
443
444static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
445{
446 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
447 unsigned long flags;
448
449 if (req->status != 0) {
450 ERROR(hidg->func.config->cdev,
451 "End Point Request ERROR: %d\n", req->status);
452 }
453
454 spin_lock_irqsave(&hidg->write_spinlock, flags);
455 hidg->write_pending = 0;
456 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
457 wake_up(&hidg->write_queue);
458}
459
460static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
461 size_t count, loff_t *offp)
462{
463 struct f_hidg *hidg = file->private_data;
464 struct usb_request *req;
465 unsigned long flags;
466 ssize_t status = -ENOMEM;
467
468 spin_lock_irqsave(&hidg->write_spinlock, flags);
469
470 if (!hidg->req) {
471 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
472 return -ESHUTDOWN;
473 }
474
475#define WRITE_COND (!hidg->write_pending)
476try_again:
477 /* write queue */
478 while (!WRITE_COND) {
479 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
480 if (file->f_flags & O_NONBLOCK)
481 return -EAGAIN;
482
483 if (wait_event_interruptible_exclusive(
484 hidg->write_queue, WRITE_COND))
485 return -ERESTARTSYS;
486
487 spin_lock_irqsave(&hidg->write_spinlock, flags);
488 }
489
490 hidg->write_pending = 1;
491 req = hidg->req;
492 count = min_t(unsigned, count, hidg->report_length);
493
494 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
495
496 if (!req) {
497 ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
498 status = -ESHUTDOWN;
499 goto release_write_pending;
500 }
501
502 status = copy_from_user(req->buf, buffer, count);
503 if (status != 0) {
504 ERROR(hidg->func.config->cdev,
505 "copy_from_user error\n");
506 status = -EINVAL;
507 goto release_write_pending;
508 }
509
510 spin_lock_irqsave(&hidg->write_spinlock, flags);
511
512 /* when our function has been disabled by host */
513 if (!hidg->req) {
514 free_ep_req(hidg->in_ep, req);
515 /*
516 * TODO
517 * Should we fail with error here?
518 */
519 goto try_again;
520 }
521
522 req->status = 0;
523 req->zero = 0;
524 req->length = count;
525 req->complete = f_hidg_req_complete;
526 req->context = hidg;
527
528 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
529
530 if (!hidg->in_ep->enabled) {
531 ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
532 status = -ESHUTDOWN;
533 goto release_write_pending;
534 }
535
536 status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
537 if (status < 0)
538 goto release_write_pending;
539 else
540 status = count;
541
542 return status;
543release_write_pending:
544 spin_lock_irqsave(&hidg->write_spinlock, flags);
545 hidg->write_pending = 0;
546 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
547
548 wake_up(&hidg->write_queue);
549
550 return status;
551}
552
553static struct report_entry *f_hidg_search_for_report(struct f_hidg *hidg, u8 report_id)
554{
555 struct list_head *ptr;
556 struct report_entry *entry;
557
558 list_for_each(ptr, &hidg->report_list) {
559 entry = list_entry(ptr, struct report_entry, node);
560 if (entry->report_data.report_id == report_id)
561 return entry;
562 }
563
564 return NULL;
565}
566
567static void get_report_workqueue_handler(struct work_struct *work)
568{
569 struct f_hidg *hidg = container_of(work, struct f_hidg, work);
570 struct usb_composite_dev *cdev = hidg->func.config->cdev;
571 struct usb_request *req;
572 struct report_entry *ptr;
573 unsigned long flags;
574
575 int status = 0;
576
577 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
578 req = hidg->get_req;
579 if (!req) {
580 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
581 return;
582 }
583
584 req->zero = 0;
585 req->length = min_t(unsigned int, min_t(unsigned int, hidg->get_report_req_report_length,
586 hidg->report_length),
587 MAX_REPORT_LENGTH);
588
589 /* Check if there is a response available for immediate response */
590 ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
591 if (ptr && !ptr->report_data.userspace_req) {
592 /* Report exists in list and it is to be used for immediate response */
593 req->buf = ptr->report_data.data;
594 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
595 hidg->get_report_returned = true;
596 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
597 } else {
598 /*
599 * Report does not exist in list or should not be immediately sent
600 * i.e. give userspace time to respond
601 */
602 hidg->get_report_returned = false;
603 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
604 wake_up(&hidg->get_id_queue);
605#define GET_REPORT_COND (!hidg->get_report_returned)
606 /* Wait until userspace has responded or timeout */
607 status = wait_event_interruptible_timeout(hidg->get_queue, !GET_REPORT_COND,
608 msecs_to_jiffies(GET_REPORT_TIMEOUT_MS));
609 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
610 req = hidg->get_req;
611 if (!req) {
612 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
613 return;
614 }
615 if (status == 0 && !hidg->get_report_returned) {
616 /* GET_REPORT request was not serviced by userspace within timeout period */
617 VDBG(cdev, "get_report : userspace timeout.\n");
618 hidg->get_report_returned = true;
619 }
620
621 /* Search again for report ID in list and respond to GET_REPORT request */
622 ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
623 if (ptr) {
624 /*
625 * Either get an updated response just serviced by userspace
626 * or send the latest response in the list
627 */
628 req->buf = ptr->report_data.data;
629 } else {
630 /* If there are no prevoiusly sent reports send empty report */
631 req->buf = hidg->get_report.data;
632 memset(req->buf, 0x0, req->length);
633 }
634
635 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
636 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
637 }
638
639 if (status < 0)
640 VDBG(cdev, "usb_ep_queue error on ep0 responding to GET_REPORT\n");
641}
642
643static int f_hidg_get_report_id(struct file *file, __u8 __user *buffer)
644{
645 struct f_hidg *hidg = file->private_data;
646 int ret = 0;
647
648 ret = put_user(hidg->get_report_req_report_id, buffer);
649
650 return ret;
651}
652
653static int f_hidg_get_report(struct file *file, struct usb_hidg_report __user *buffer)
654{
655 struct f_hidg *hidg = file->private_data;
656 struct usb_composite_dev *cdev = hidg->func.config->cdev;
657 unsigned long flags;
658 struct report_entry *entry;
659 struct report_entry *ptr;
660 __u8 report_id;
661
662 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
663 if (!entry)
664 return -ENOMEM;
665
666 if (copy_from_user(&entry->report_data, buffer,
667 sizeof(struct usb_hidg_report))) {
668 ERROR(cdev, "copy_from_user error\n");
669 kfree(entry);
670 return -EINVAL;
671 }
672
673 report_id = entry->report_data.report_id;
674
675 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
676 ptr = f_hidg_search_for_report(hidg, report_id);
677
678 if (ptr) {
679 /* Report already exists in list - update it */
680 if (copy_from_user(&ptr->report_data, buffer,
681 sizeof(struct usb_hidg_report))) {
682 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
683 ERROR(cdev, "copy_from_user error\n");
684 kfree(entry);
685 return -EINVAL;
686 }
687 kfree(entry);
688 } else {
689 /* Report does not exist in list - add it */
690 list_add_tail(&entry->node, &hidg->report_list);
691 }
692
693 /* If there is no response pending then do nothing further */
694 if (hidg->get_report_returned) {
695 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
696 return 0;
697 }
698
699 /* If this userspace response serves the current pending report */
700 if (hidg->get_report_req_report_id == report_id) {
701 hidg->get_report_returned = true;
702 wake_up(&hidg->get_queue);
703 }
704
705 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
706 return 0;
707}
708
709static long f_hidg_ioctl(struct file *file, unsigned int code, unsigned long arg)
710{
711 switch (code) {
712 case GADGET_HID_READ_GET_REPORT_ID:
713 return f_hidg_get_report_id(file, (__u8 __user *)arg);
714 case GADGET_HID_WRITE_GET_REPORT:
715 return f_hidg_get_report(file, (struct usb_hidg_report __user *)arg);
716 default:
717 return -ENOTTY;
718 }
719}
720
721static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
722{
723 struct f_hidg *hidg = file->private_data;
724 __poll_t ret = 0;
725
726 poll_wait(file, &hidg->read_queue, wait);
727 poll_wait(file, &hidg->write_queue, wait);
728 poll_wait(file, &hidg->get_queue, wait);
729 poll_wait(file, &hidg->get_id_queue, wait);
730
731 if (WRITE_COND)
732 ret |= EPOLLOUT | EPOLLWRNORM;
733
734 if (hidg->use_out_ep) {
735 if (READ_COND_INTOUT)
736 ret |= EPOLLIN | EPOLLRDNORM;
737 } else {
738 if (READ_COND_SSREPORT)
739 ret |= EPOLLIN | EPOLLRDNORM;
740 }
741
742 if (GET_REPORT_COND)
743 ret |= EPOLLPRI;
744
745 return ret;
746}
747
748#undef WRITE_COND
749#undef READ_COND_SSREPORT
750#undef READ_COND_INTOUT
751#undef GET_REPORT_COND
752
753static int f_hidg_release(struct inode *inode, struct file *fd)
754{
755 fd->private_data = NULL;
756 return 0;
757}
758
759static int f_hidg_open(struct inode *inode, struct file *fd)
760{
761 struct f_hidg *hidg =
762 container_of(inode->i_cdev, struct f_hidg, cdev);
763
764 fd->private_data = hidg;
765
766 return 0;
767}
768
769/*-------------------------------------------------------------------------*/
770/* usb_function */
771
772static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
773 unsigned length)
774{
775 return alloc_ep_req(ep, length);
776}
777
778static void hidg_intout_complete(struct usb_ep *ep, struct usb_request *req)
779{
780 struct f_hidg *hidg = (struct f_hidg *) req->context;
781 struct usb_composite_dev *cdev = hidg->func.config->cdev;
782 struct f_hidg_req_list *req_list;
783 unsigned long flags;
784
785 switch (req->status) {
786 case 0:
787 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
788 if (!req_list) {
789 ERROR(cdev, "Unable to allocate mem for req_list\n");
790 goto free_req;
791 }
792
793 req_list->req = req;
794
795 spin_lock_irqsave(&hidg->read_spinlock, flags);
796 list_add_tail(&req_list->list, &hidg->completed_out_req);
797 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
798
799 wake_up(&hidg->read_queue);
800 break;
801 default:
802 ERROR(cdev, "Set report failed %d\n", req->status);
803 fallthrough;
804 case -ECONNABORTED: /* hardware forced ep reset */
805 case -ECONNRESET: /* request dequeued */
806 case -ESHUTDOWN: /* disconnect from host */
807free_req:
808 free_ep_req(ep, req);
809 return;
810 }
811}
812
813static void hidg_ssreport_complete(struct usb_ep *ep, struct usb_request *req)
814{
815 struct f_hidg *hidg = (struct f_hidg *)req->context;
816 struct usb_composite_dev *cdev = hidg->func.config->cdev;
817 char *new_buf = NULL;
818 unsigned long flags;
819
820 if (req->status != 0 || req->buf == NULL || req->actual == 0) {
821 ERROR(cdev,
822 "%s FAILED: status=%d, buf=%p, actual=%d\n",
823 __func__, req->status, req->buf, req->actual);
824 return;
825 }
826
827 spin_lock_irqsave(&hidg->read_spinlock, flags);
828
829 new_buf = krealloc(hidg->set_report_buf, req->actual, GFP_ATOMIC);
830 if (new_buf == NULL) {
831 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
832 return;
833 }
834 hidg->set_report_buf = new_buf;
835
836 hidg->set_report_length = req->actual;
837 memcpy(hidg->set_report_buf, req->buf, req->actual);
838
839 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
840
841 wake_up(&hidg->read_queue);
842}
843
844static void hidg_get_report_complete(struct usb_ep *ep, struct usb_request *req)
845{
846}
847
848static int hidg_setup(struct usb_function *f,
849 const struct usb_ctrlrequest *ctrl)
850{
851 struct f_hidg *hidg = func_to_hidg(f);
852 struct usb_composite_dev *cdev = f->config->cdev;
853 struct usb_request *req = cdev->req;
854 int status = 0;
855 __u16 value, length;
856 unsigned long flags;
857
858 value = __le16_to_cpu(ctrl->wValue);
859 length = __le16_to_cpu(ctrl->wLength);
860
861 VDBG(cdev,
862 "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
863 __func__, ctrl->bRequestType, ctrl->bRequest, value);
864
865 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
866 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
867 | HID_REQ_GET_REPORT):
868 VDBG(cdev, "get_report | wLength=%d\n", ctrl->wLength);
869
870 /*
871 * Update GET_REPORT ID so that an ioctl can be used to determine what
872 * GET_REPORT the request was actually for.
873 */
874 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
875 hidg->get_report_req_report_id = value & 0xff;
876 hidg->get_report_req_report_length = length;
877 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
878
879 queue_work(hidg->workqueue, &hidg->work);
880
881 return status;
882
883 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
884 | HID_REQ_GET_PROTOCOL):
885 VDBG(cdev, "get_protocol\n");
886 length = min_t(unsigned int, length, 1);
887 ((u8 *) req->buf)[0] = hidg->protocol;
888 goto respond;
889 break;
890
891 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
892 | HID_REQ_GET_IDLE):
893 VDBG(cdev, "get_idle\n");
894 length = min_t(unsigned int, length, 1);
895 ((u8 *) req->buf)[0] = hidg->idle;
896 goto respond;
897 break;
898
899 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
900 | HID_REQ_SET_REPORT):
901 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
902 if (hidg->use_out_ep)
903 goto stall;
904 req->complete = hidg_ssreport_complete;
905 req->context = hidg;
906 goto respond;
907 break;
908
909 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
910 | HID_REQ_SET_PROTOCOL):
911 VDBG(cdev, "set_protocol\n");
912 if (value > HID_REPORT_PROTOCOL)
913 goto stall;
914 length = 0;
915 /*
916 * We assume that programs implementing the Boot protocol
917 * are also compatible with the Report Protocol
918 */
919 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
920 hidg->protocol = value;
921 goto respond;
922 }
923 goto stall;
924 break;
925
926 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
927 | HID_REQ_SET_IDLE):
928 VDBG(cdev, "set_idle\n");
929 length = 0;
930 hidg->idle = value >> 8;
931 goto respond;
932 break;
933
934 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
935 | USB_REQ_GET_DESCRIPTOR):
936 switch (value >> 8) {
937 case HID_DT_HID:
938 {
939 struct hid_descriptor hidg_desc_copy = hidg_desc;
940
941 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
942 hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
943 hidg_desc_copy.desc[0].wDescriptorLength =
944 cpu_to_le16(hidg->report_desc_length);
945
946 length = min_t(unsigned short, length,
947 hidg_desc_copy.bLength);
948 memcpy(req->buf, &hidg_desc_copy, length);
949 goto respond;
950 break;
951 }
952 case HID_DT_REPORT:
953 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
954 length = min_t(unsigned short, length,
955 hidg->report_desc_length);
956 memcpy(req->buf, hidg->report_desc, length);
957 goto respond;
958 break;
959
960 default:
961 VDBG(cdev, "Unknown descriptor request 0x%x\n",
962 value >> 8);
963 goto stall;
964 break;
965 }
966 break;
967
968 default:
969 VDBG(cdev, "Unknown request 0x%x\n",
970 ctrl->bRequest);
971 goto stall;
972 break;
973 }
974
975stall:
976 return -EOPNOTSUPP;
977
978respond:
979 req->zero = 0;
980 req->length = length;
981 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
982 if (status < 0)
983 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
984 return status;
985}
986
987static void hidg_disable(struct usb_function *f)
988{
989 struct f_hidg *hidg = func_to_hidg(f);
990 struct f_hidg_req_list *list, *next;
991 unsigned long flags;
992
993 usb_ep_disable(hidg->in_ep);
994
995 if (hidg->out_ep) {
996 usb_ep_disable(hidg->out_ep);
997
998 spin_lock_irqsave(&hidg->read_spinlock, flags);
999 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
1000 free_ep_req(hidg->out_ep, list->req);
1001 list_del(&list->list);
1002 kfree(list);
1003 }
1004 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
1005 }
1006
1007 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
1008 if (!hidg->get_report_returned) {
1009 usb_ep_free_request(f->config->cdev->gadget->ep0, hidg->get_req);
1010 hidg->get_req = NULL;
1011 hidg->get_report_returned = true;
1012 }
1013 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
1014
1015 spin_lock_irqsave(&hidg->write_spinlock, flags);
1016 if (!hidg->write_pending) {
1017 free_ep_req(hidg->in_ep, hidg->req);
1018 hidg->write_pending = 1;
1019 }
1020
1021 hidg->req = NULL;
1022 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
1023}
1024
1025static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
1026{
1027 struct usb_composite_dev *cdev = f->config->cdev;
1028 struct f_hidg *hidg = func_to_hidg(f);
1029 struct usb_request *req_in = NULL;
1030 unsigned long flags;
1031 int i, status = 0;
1032
1033 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
1034
1035 if (hidg->in_ep != NULL) {
1036 /* restart endpoint */
1037 usb_ep_disable(hidg->in_ep);
1038
1039 status = config_ep_by_speed(f->config->cdev->gadget, f,
1040 hidg->in_ep);
1041 if (status) {
1042 ERROR(cdev, "config_ep_by_speed FAILED!\n");
1043 goto fail;
1044 }
1045 status = usb_ep_enable(hidg->in_ep);
1046 if (status < 0) {
1047 ERROR(cdev, "Enable IN endpoint FAILED!\n");
1048 goto fail;
1049 }
1050 hidg->in_ep->driver_data = hidg;
1051
1052 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
1053 if (!req_in) {
1054 status = -ENOMEM;
1055 goto disable_ep_in;
1056 }
1057 }
1058
1059 if (hidg->use_out_ep && hidg->out_ep != NULL) {
1060 /* restart endpoint */
1061 usb_ep_disable(hidg->out_ep);
1062
1063 status = config_ep_by_speed(f->config->cdev->gadget, f,
1064 hidg->out_ep);
1065 if (status) {
1066 ERROR(cdev, "config_ep_by_speed FAILED!\n");
1067 goto free_req_in;
1068 }
1069 status = usb_ep_enable(hidg->out_ep);
1070 if (status < 0) {
1071 ERROR(cdev, "Enable OUT endpoint FAILED!\n");
1072 goto free_req_in;
1073 }
1074 hidg->out_ep->driver_data = hidg;
1075
1076 /*
1077 * allocate a bunch of read buffers and queue them all at once.
1078 */
1079 for (i = 0; i < hidg->qlen && status == 0; i++) {
1080 struct usb_request *req =
1081 hidg_alloc_ep_req(hidg->out_ep,
1082 hidg->report_length);
1083 if (req) {
1084 req->complete = hidg_intout_complete;
1085 req->context = hidg;
1086 status = usb_ep_queue(hidg->out_ep, req,
1087 GFP_ATOMIC);
1088 if (status) {
1089 ERROR(cdev, "%s queue req --> %d\n",
1090 hidg->out_ep->name, status);
1091 free_ep_req(hidg->out_ep, req);
1092 }
1093 } else {
1094 status = -ENOMEM;
1095 goto disable_out_ep;
1096 }
1097 }
1098 }
1099
1100 if (hidg->in_ep != NULL) {
1101 spin_lock_irqsave(&hidg->write_spinlock, flags);
1102 hidg->req = req_in;
1103 hidg->write_pending = 0;
1104 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
1105
1106 wake_up(&hidg->write_queue);
1107 }
1108 return 0;
1109disable_out_ep:
1110 if (hidg->out_ep)
1111 usb_ep_disable(hidg->out_ep);
1112free_req_in:
1113 if (req_in)
1114 free_ep_req(hidg->in_ep, req_in);
1115
1116disable_ep_in:
1117 if (hidg->in_ep)
1118 usb_ep_disable(hidg->in_ep);
1119
1120fail:
1121 return status;
1122}
1123
1124#ifdef CONFIG_COMPAT
1125static long f_hidg_compat_ioctl(struct file *file, unsigned int code,
1126 unsigned long value)
1127{
1128 return f_hidg_ioctl(file, code, value);
1129}
1130#endif
1131
1132static const struct file_operations f_hidg_fops = {
1133 .owner = THIS_MODULE,
1134 .open = f_hidg_open,
1135 .release = f_hidg_release,
1136 .write = f_hidg_write,
1137 .read = f_hidg_read,
1138 .poll = f_hidg_poll,
1139 .unlocked_ioctl = f_hidg_ioctl,
1140#ifdef CONFIG_COMPAT
1141 .compat_ioctl = f_hidg_compat_ioctl,
1142#endif
1143 .llseek = noop_llseek,
1144};
1145
1146static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
1147{
1148 struct usb_ep *ep;
1149 struct f_hidg *hidg = func_to_hidg(f);
1150 struct usb_string *us;
1151 int status;
1152
1153 hidg->get_req = usb_ep_alloc_request(c->cdev->gadget->ep0, GFP_ATOMIC);
1154 if (!hidg->get_req)
1155 return -ENOMEM;
1156
1157 hidg->get_req->zero = 0;
1158 hidg->get_req->complete = hidg_get_report_complete;
1159 hidg->get_req->context = hidg;
1160 hidg->get_report_returned = true;
1161
1162 /* maybe allocate device-global string IDs, and patch descriptors */
1163 us = usb_gstrings_attach(c->cdev, ct_func_strings,
1164 ARRAY_SIZE(ct_func_string_defs));
1165 if (IS_ERR(us))
1166 return PTR_ERR(us);
1167 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
1168
1169 /* allocate instance-specific interface IDs, and patch descriptors */
1170 status = usb_interface_id(c, f);
1171 if (status < 0)
1172 goto fail;
1173 hidg_interface_desc.bInterfaceNumber = status;
1174
1175 /* allocate instance-specific endpoints */
1176 status = -ENODEV;
1177 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
1178 if (!ep)
1179 goto fail;
1180 hidg->in_ep = ep;
1181
1182 hidg->out_ep = NULL;
1183 if (hidg->use_out_ep) {
1184 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
1185 if (!ep)
1186 goto fail;
1187 hidg->out_ep = ep;
1188 }
1189
1190 /* used only if use_out_ep == 1 */
1191 hidg->set_report_buf = NULL;
1192
1193 /* set descriptor dynamic values */
1194 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
1195 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
1196 hidg_interface_desc.bNumEndpoints = hidg->use_out_ep ? 2 : 1;
1197 hidg->protocol = HID_REPORT_PROTOCOL;
1198 hidg->idle = 1;
1199 hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1200 hidg_ss_in_comp_desc.wBytesPerInterval =
1201 cpu_to_le16(hidg->report_length);
1202 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1203 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1204 hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1205 hidg_ss_out_comp_desc.wBytesPerInterval =
1206 cpu_to_le16(hidg->report_length);
1207 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1208 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1209 /*
1210 * We can use hidg_desc struct here but we should not relay
1211 * that its content won't change after returning from this function.
1212 */
1213 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
1214 hidg_desc.desc[0].wDescriptorLength =
1215 cpu_to_le16(hidg->report_desc_length);
1216
1217 hidg_hs_in_ep_desc.bEndpointAddress =
1218 hidg_fs_in_ep_desc.bEndpointAddress;
1219 hidg_hs_out_ep_desc.bEndpointAddress =
1220 hidg_fs_out_ep_desc.bEndpointAddress;
1221
1222 hidg_ss_in_ep_desc.bEndpointAddress =
1223 hidg_fs_in_ep_desc.bEndpointAddress;
1224 hidg_ss_out_ep_desc.bEndpointAddress =
1225 hidg_fs_out_ep_desc.bEndpointAddress;
1226
1227 if (hidg->use_out_ep)
1228 status = usb_assign_descriptors(f,
1229 hidg_fs_descriptors_intout,
1230 hidg_hs_descriptors_intout,
1231 hidg_ss_descriptors_intout,
1232 hidg_ss_descriptors_intout);
1233 else
1234 status = usb_assign_descriptors(f,
1235 hidg_fs_descriptors_ssreport,
1236 hidg_hs_descriptors_ssreport,
1237 hidg_ss_descriptors_ssreport,
1238 hidg_ss_descriptors_ssreport);
1239
1240 if (status)
1241 goto fail;
1242
1243 spin_lock_init(&hidg->write_spinlock);
1244 hidg->write_pending = 1;
1245 hidg->req = NULL;
1246 spin_lock_init(&hidg->read_spinlock);
1247 spin_lock_init(&hidg->get_report_spinlock);
1248 init_waitqueue_head(&hidg->write_queue);
1249 init_waitqueue_head(&hidg->read_queue);
1250 init_waitqueue_head(&hidg->get_queue);
1251 init_waitqueue_head(&hidg->get_id_queue);
1252 INIT_LIST_HEAD(&hidg->completed_out_req);
1253 INIT_LIST_HEAD(&hidg->report_list);
1254
1255 INIT_WORK(&hidg->work, get_report_workqueue_handler);
1256 hidg->workqueue = alloc_workqueue("report_work",
1257 WQ_FREEZABLE |
1258 WQ_MEM_RECLAIM,
1259 1);
1260
1261 if (!hidg->workqueue) {
1262 status = -ENOMEM;
1263 goto fail;
1264 }
1265
1266 /* create char device */
1267 cdev_init(&hidg->cdev, &f_hidg_fops);
1268 status = cdev_device_add(&hidg->cdev, &hidg->dev);
1269 if (status)
1270 goto fail_free_descs;
1271
1272 return 0;
1273fail_free_descs:
1274 destroy_workqueue(hidg->workqueue);
1275 usb_free_all_descriptors(f);
1276fail:
1277 ERROR(f->config->cdev, "hidg_bind FAILED\n");
1278 if (hidg->req != NULL)
1279 free_ep_req(hidg->in_ep, hidg->req);
1280
1281 usb_ep_free_request(c->cdev->gadget->ep0, hidg->get_req);
1282 hidg->get_req = NULL;
1283
1284 return status;
1285}
1286
1287static inline int hidg_get_minor(void)
1288{
1289 int ret;
1290
1291 ret = ida_alloc(&hidg_ida, GFP_KERNEL);
1292 if (ret >= HIDG_MINORS) {
1293 ida_free(&hidg_ida, ret);
1294 ret = -ENODEV;
1295 }
1296
1297 return ret;
1298}
1299
1300static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
1301{
1302 return container_of(to_config_group(item), struct f_hid_opts,
1303 func_inst.group);
1304}
1305
1306static void hid_attr_release(struct config_item *item)
1307{
1308 struct f_hid_opts *opts = to_f_hid_opts(item);
1309
1310 usb_put_function_instance(&opts->func_inst);
1311}
1312
1313static struct configfs_item_operations hidg_item_ops = {
1314 .release = hid_attr_release,
1315};
1316
1317#define F_HID_OPT(name, prec, limit) \
1318static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
1319{ \
1320 struct f_hid_opts *opts = to_f_hid_opts(item); \
1321 int result; \
1322 \
1323 mutex_lock(&opts->lock); \
1324 result = sprintf(page, "%d\n", opts->name); \
1325 mutex_unlock(&opts->lock); \
1326 \
1327 return result; \
1328} \
1329 \
1330static ssize_t f_hid_opts_##name##_store(struct config_item *item, \
1331 const char *page, size_t len) \
1332{ \
1333 struct f_hid_opts *opts = to_f_hid_opts(item); \
1334 int ret; \
1335 u##prec num; \
1336 \
1337 mutex_lock(&opts->lock); \
1338 if (opts->refcnt) { \
1339 ret = -EBUSY; \
1340 goto end; \
1341 } \
1342 \
1343 ret = kstrtou##prec(page, 0, &num); \
1344 if (ret) \
1345 goto end; \
1346 \
1347 if (num > limit) { \
1348 ret = -EINVAL; \
1349 goto end; \
1350 } \
1351 opts->name = num; \
1352 ret = len; \
1353 \
1354end: \
1355 mutex_unlock(&opts->lock); \
1356 return ret; \
1357} \
1358 \
1359CONFIGFS_ATTR(f_hid_opts_, name)
1360
1361F_HID_OPT(subclass, 8, 255);
1362F_HID_OPT(protocol, 8, 255);
1363F_HID_OPT(no_out_endpoint, 8, 1);
1364F_HID_OPT(report_length, 16, 65535);
1365
1366static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
1367{
1368 struct f_hid_opts *opts = to_f_hid_opts(item);
1369 int result;
1370
1371 mutex_lock(&opts->lock);
1372 result = opts->report_desc_length;
1373 memcpy(page, opts->report_desc, opts->report_desc_length);
1374 mutex_unlock(&opts->lock);
1375
1376 return result;
1377}
1378
1379static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
1380 const char *page, size_t len)
1381{
1382 struct f_hid_opts *opts = to_f_hid_opts(item);
1383 int ret = -EBUSY;
1384 char *d;
1385
1386 mutex_lock(&opts->lock);
1387
1388 if (opts->refcnt)
1389 goto end;
1390 if (len > PAGE_SIZE) {
1391 ret = -ENOSPC;
1392 goto end;
1393 }
1394 d = kmemdup(page, len, GFP_KERNEL);
1395 if (!d) {
1396 ret = -ENOMEM;
1397 goto end;
1398 }
1399 kfree(opts->report_desc);
1400 opts->report_desc = d;
1401 opts->report_desc_length = len;
1402 opts->report_desc_alloc = true;
1403 ret = len;
1404end:
1405 mutex_unlock(&opts->lock);
1406 return ret;
1407}
1408
1409CONFIGFS_ATTR(f_hid_opts_, report_desc);
1410
1411static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1412{
1413 struct f_hid_opts *opts = to_f_hid_opts(item);
1414
1415 return sprintf(page, "%d:%d\n", major, opts->minor);
1416}
1417
1418CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1419
1420static struct configfs_attribute *hid_attrs[] = {
1421 &f_hid_opts_attr_subclass,
1422 &f_hid_opts_attr_protocol,
1423 &f_hid_opts_attr_no_out_endpoint,
1424 &f_hid_opts_attr_report_length,
1425 &f_hid_opts_attr_report_desc,
1426 &f_hid_opts_attr_dev,
1427 NULL,
1428};
1429
1430static const struct config_item_type hid_func_type = {
1431 .ct_item_ops = &hidg_item_ops,
1432 .ct_attrs = hid_attrs,
1433 .ct_owner = THIS_MODULE,
1434};
1435
1436static inline void hidg_put_minor(int minor)
1437{
1438 ida_free(&hidg_ida, minor);
1439}
1440
1441static void hidg_free_inst(struct usb_function_instance *f)
1442{
1443 struct f_hid_opts *opts;
1444
1445 opts = container_of(f, struct f_hid_opts, func_inst);
1446
1447 mutex_lock(&hidg_ida_lock);
1448
1449 hidg_put_minor(opts->minor);
1450 if (ida_is_empty(&hidg_ida))
1451 ghid_cleanup();
1452
1453 mutex_unlock(&hidg_ida_lock);
1454
1455 if (opts->report_desc_alloc)
1456 kfree(opts->report_desc);
1457
1458 kfree(opts);
1459}
1460
1461static struct usb_function_instance *hidg_alloc_inst(void)
1462{
1463 struct f_hid_opts *opts;
1464 struct usb_function_instance *ret;
1465 int status = 0;
1466
1467 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1468 if (!opts)
1469 return ERR_PTR(-ENOMEM);
1470 mutex_init(&opts->lock);
1471 opts->func_inst.free_func_inst = hidg_free_inst;
1472 ret = &opts->func_inst;
1473
1474 mutex_lock(&hidg_ida_lock);
1475
1476 if (ida_is_empty(&hidg_ida)) {
1477 status = ghid_setup(NULL, HIDG_MINORS);
1478 if (status) {
1479 ret = ERR_PTR(status);
1480 kfree(opts);
1481 goto unlock;
1482 }
1483 }
1484
1485 opts->minor = hidg_get_minor();
1486 if (opts->minor < 0) {
1487 ret = ERR_PTR(opts->minor);
1488 kfree(opts);
1489 if (ida_is_empty(&hidg_ida))
1490 ghid_cleanup();
1491 goto unlock;
1492 }
1493 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1494
1495unlock:
1496 mutex_unlock(&hidg_ida_lock);
1497 return ret;
1498}
1499
1500static void hidg_free(struct usb_function *f)
1501{
1502 struct f_hidg *hidg;
1503 struct f_hid_opts *opts;
1504
1505 hidg = func_to_hidg(f);
1506 opts = container_of(f->fi, struct f_hid_opts, func_inst);
1507 put_device(&hidg->dev);
1508 mutex_lock(&opts->lock);
1509 --opts->refcnt;
1510 mutex_unlock(&opts->lock);
1511}
1512
1513static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1514{
1515 struct f_hidg *hidg = func_to_hidg(f);
1516
1517 cdev_device_del(&hidg->cdev, &hidg->dev);
1518 destroy_workqueue(hidg->workqueue);
1519 usb_free_all_descriptors(f);
1520}
1521
1522static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1523{
1524 struct f_hidg *hidg;
1525 struct f_hid_opts *opts;
1526 int ret;
1527
1528 /* allocate and initialize one new instance */
1529 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1530 if (!hidg)
1531 return ERR_PTR(-ENOMEM);
1532
1533 opts = container_of(fi, struct f_hid_opts, func_inst);
1534
1535 mutex_lock(&opts->lock);
1536
1537 device_initialize(&hidg->dev);
1538 hidg->dev.release = hidg_release;
1539 hidg->dev.class = &hidg_class;
1540 hidg->dev.devt = MKDEV(major, opts->minor);
1541 ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
1542 if (ret)
1543 goto err_unlock;
1544
1545 hidg->bInterfaceSubClass = opts->subclass;
1546 hidg->bInterfaceProtocol = opts->protocol;
1547 hidg->report_length = opts->report_length;
1548 hidg->report_desc_length = opts->report_desc_length;
1549 if (opts->report_desc) {
1550 hidg->report_desc = kmemdup(opts->report_desc,
1551 opts->report_desc_length,
1552 GFP_KERNEL);
1553 if (!hidg->report_desc) {
1554 ret = -ENOMEM;
1555 goto err_put_device;
1556 }
1557 }
1558 hidg->use_out_ep = !opts->no_out_endpoint;
1559
1560 ++opts->refcnt;
1561 mutex_unlock(&opts->lock);
1562
1563 hidg->func.name = "hid";
1564 hidg->func.bind = hidg_bind;
1565 hidg->func.unbind = hidg_unbind;
1566 hidg->func.set_alt = hidg_set_alt;
1567 hidg->func.disable = hidg_disable;
1568 hidg->func.setup = hidg_setup;
1569 hidg->func.free_func = hidg_free;
1570
1571 /* this could be made configurable at some point */
1572 hidg->qlen = 4;
1573
1574 return &hidg->func;
1575
1576err_put_device:
1577 put_device(&hidg->dev);
1578err_unlock:
1579 mutex_unlock(&opts->lock);
1580 return ERR_PTR(ret);
1581}
1582
1583DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1584MODULE_DESCRIPTION("USB HID function driver");
1585MODULE_LICENSE("GPL");
1586MODULE_AUTHOR("Fabien Chouteau");
1587
1588int ghid_setup(struct usb_gadget *g, int count)
1589{
1590 int status;
1591 dev_t dev;
1592
1593 status = class_register(&hidg_class);
1594 if (status)
1595 return status;
1596
1597 status = alloc_chrdev_region(&dev, 0, count, "hidg");
1598 if (status) {
1599 class_unregister(&hidg_class);
1600 return status;
1601 }
1602
1603 major = MAJOR(dev);
1604 minors = count;
1605
1606 return 0;
1607}
1608
1609void ghid_cleanup(void)
1610{
1611 if (major) {
1612 unregister_chrdev_region(MKDEV(major, 0), minors);
1613 major = minors = 0;
1614 }
1615
1616 class_unregister(&hidg_class);
1617}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_hid.c -- USB HID function driver
4 *
5 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/hid.h>
11#include <linux/idr.h>
12#include <linux/cdev.h>
13#include <linux/mutex.h>
14#include <linux/poll.h>
15#include <linux/uaccess.h>
16#include <linux/wait.h>
17#include <linux/sched.h>
18#include <linux/usb/g_hid.h>
19
20#include "u_f.h"
21#include "u_hid.h"
22
23#define HIDG_MINORS 4
24
25static int major, minors;
26static struct class *hidg_class;
27static DEFINE_IDA(hidg_ida);
28static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
29
30/*-------------------------------------------------------------------------*/
31/* HID gadget struct */
32
33struct f_hidg_req_list {
34 struct usb_request *req;
35 unsigned int pos;
36 struct list_head list;
37};
38
39struct f_hidg {
40 /* configuration */
41 unsigned char bInterfaceSubClass;
42 unsigned char bInterfaceProtocol;
43 unsigned char protocol;
44 unsigned short report_desc_length;
45 char *report_desc;
46 unsigned short report_length;
47
48 /* recv report */
49 struct list_head completed_out_req;
50 spinlock_t read_spinlock;
51 wait_queue_head_t read_queue;
52 unsigned int qlen;
53
54 /* send report */
55 spinlock_t write_spinlock;
56 bool write_pending;
57 wait_queue_head_t write_queue;
58 struct usb_request *req;
59
60 int minor;
61 struct cdev cdev;
62 struct usb_function func;
63
64 struct usb_ep *in_ep;
65 struct usb_ep *out_ep;
66};
67
68static inline struct f_hidg *func_to_hidg(struct usb_function *f)
69{
70 return container_of(f, struct f_hidg, func);
71}
72
73/*-------------------------------------------------------------------------*/
74/* Static descriptors */
75
76static struct usb_interface_descriptor hidg_interface_desc = {
77 .bLength = sizeof hidg_interface_desc,
78 .bDescriptorType = USB_DT_INTERFACE,
79 /* .bInterfaceNumber = DYNAMIC */
80 .bAlternateSetting = 0,
81 .bNumEndpoints = 2,
82 .bInterfaceClass = USB_CLASS_HID,
83 /* .bInterfaceSubClass = DYNAMIC */
84 /* .bInterfaceProtocol = DYNAMIC */
85 /* .iInterface = DYNAMIC */
86};
87
88static struct hid_descriptor hidg_desc = {
89 .bLength = sizeof hidg_desc,
90 .bDescriptorType = HID_DT_HID,
91 .bcdHID = 0x0101,
92 .bCountryCode = 0x00,
93 .bNumDescriptors = 0x1,
94 /*.desc[0].bDescriptorType = DYNAMIC */
95 /*.desc[0].wDescriptorLenght = DYNAMIC */
96};
97
98/* Super-Speed Support */
99
100static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
101 .bLength = USB_DT_ENDPOINT_SIZE,
102 .bDescriptorType = USB_DT_ENDPOINT,
103 .bEndpointAddress = USB_DIR_IN,
104 .bmAttributes = USB_ENDPOINT_XFER_INT,
105 /*.wMaxPacketSize = DYNAMIC */
106 .bInterval = 4, /* FIXME: Add this field in the
107 * HID gadget configuration?
108 * (struct hidg_func_descriptor)
109 */
110};
111
112static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
113 .bLength = sizeof(hidg_ss_in_comp_desc),
114 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
115
116 /* .bMaxBurst = 0, */
117 /* .bmAttributes = 0, */
118 /* .wBytesPerInterval = DYNAMIC */
119};
120
121static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
122 .bLength = USB_DT_ENDPOINT_SIZE,
123 .bDescriptorType = USB_DT_ENDPOINT,
124 .bEndpointAddress = USB_DIR_OUT,
125 .bmAttributes = USB_ENDPOINT_XFER_INT,
126 /*.wMaxPacketSize = DYNAMIC */
127 .bInterval = 4, /* FIXME: Add this field in the
128 * HID gadget configuration?
129 * (struct hidg_func_descriptor)
130 */
131};
132
133static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
134 .bLength = sizeof(hidg_ss_out_comp_desc),
135 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
136
137 /* .bMaxBurst = 0, */
138 /* .bmAttributes = 0, */
139 /* .wBytesPerInterval = DYNAMIC */
140};
141
142static struct usb_descriptor_header *hidg_ss_descriptors[] = {
143 (struct usb_descriptor_header *)&hidg_interface_desc,
144 (struct usb_descriptor_header *)&hidg_desc,
145 (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
146 (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
147 (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
148 (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
149 NULL,
150};
151
152/* High-Speed Support */
153
154static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
155 .bLength = USB_DT_ENDPOINT_SIZE,
156 .bDescriptorType = USB_DT_ENDPOINT,
157 .bEndpointAddress = USB_DIR_IN,
158 .bmAttributes = USB_ENDPOINT_XFER_INT,
159 /*.wMaxPacketSize = DYNAMIC */
160 .bInterval = 4, /* FIXME: Add this field in the
161 * HID gadget configuration?
162 * (struct hidg_func_descriptor)
163 */
164};
165
166static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
167 .bLength = USB_DT_ENDPOINT_SIZE,
168 .bDescriptorType = USB_DT_ENDPOINT,
169 .bEndpointAddress = USB_DIR_OUT,
170 .bmAttributes = USB_ENDPOINT_XFER_INT,
171 /*.wMaxPacketSize = DYNAMIC */
172 .bInterval = 4, /* FIXME: Add this field in the
173 * HID gadget configuration?
174 * (struct hidg_func_descriptor)
175 */
176};
177
178static struct usb_descriptor_header *hidg_hs_descriptors[] = {
179 (struct usb_descriptor_header *)&hidg_interface_desc,
180 (struct usb_descriptor_header *)&hidg_desc,
181 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
182 (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
183 NULL,
184};
185
186/* Full-Speed Support */
187
188static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
189 .bLength = USB_DT_ENDPOINT_SIZE,
190 .bDescriptorType = USB_DT_ENDPOINT,
191 .bEndpointAddress = USB_DIR_IN,
192 .bmAttributes = USB_ENDPOINT_XFER_INT,
193 /*.wMaxPacketSize = DYNAMIC */
194 .bInterval = 10, /* FIXME: Add this field in the
195 * HID gadget configuration?
196 * (struct hidg_func_descriptor)
197 */
198};
199
200static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
201 .bLength = USB_DT_ENDPOINT_SIZE,
202 .bDescriptorType = USB_DT_ENDPOINT,
203 .bEndpointAddress = USB_DIR_OUT,
204 .bmAttributes = USB_ENDPOINT_XFER_INT,
205 /*.wMaxPacketSize = DYNAMIC */
206 .bInterval = 10, /* FIXME: Add this field in the
207 * HID gadget configuration?
208 * (struct hidg_func_descriptor)
209 */
210};
211
212static struct usb_descriptor_header *hidg_fs_descriptors[] = {
213 (struct usb_descriptor_header *)&hidg_interface_desc,
214 (struct usb_descriptor_header *)&hidg_desc,
215 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
216 (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
217 NULL,
218};
219
220/*-------------------------------------------------------------------------*/
221/* Strings */
222
223#define CT_FUNC_HID_IDX 0
224
225static struct usb_string ct_func_string_defs[] = {
226 [CT_FUNC_HID_IDX].s = "HID Interface",
227 {}, /* end of list */
228};
229
230static struct usb_gadget_strings ct_func_string_table = {
231 .language = 0x0409, /* en-US */
232 .strings = ct_func_string_defs,
233};
234
235static struct usb_gadget_strings *ct_func_strings[] = {
236 &ct_func_string_table,
237 NULL,
238};
239
240/*-------------------------------------------------------------------------*/
241/* Char Device */
242
243static ssize_t f_hidg_read(struct file *file, char __user *buffer,
244 size_t count, loff_t *ptr)
245{
246 struct f_hidg *hidg = file->private_data;
247 struct f_hidg_req_list *list;
248 struct usb_request *req;
249 unsigned long flags;
250 int ret;
251
252 if (!count)
253 return 0;
254
255 spin_lock_irqsave(&hidg->read_spinlock, flags);
256
257#define READ_COND (!list_empty(&hidg->completed_out_req))
258
259 /* wait for at least one buffer to complete */
260 while (!READ_COND) {
261 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
262 if (file->f_flags & O_NONBLOCK)
263 return -EAGAIN;
264
265 if (wait_event_interruptible(hidg->read_queue, READ_COND))
266 return -ERESTARTSYS;
267
268 spin_lock_irqsave(&hidg->read_spinlock, flags);
269 }
270
271 /* pick the first one */
272 list = list_first_entry(&hidg->completed_out_req,
273 struct f_hidg_req_list, list);
274
275 /*
276 * Remove this from list to protect it from beign free()
277 * while host disables our function
278 */
279 list_del(&list->list);
280
281 req = list->req;
282 count = min_t(unsigned int, count, req->actual - list->pos);
283 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
284
285 /* copy to user outside spinlock */
286 count -= copy_to_user(buffer, req->buf + list->pos, count);
287 list->pos += count;
288
289 /*
290 * if this request is completely handled and transfered to
291 * userspace, remove its entry from the list and requeue it
292 * again. Otherwise, we will revisit it again upon the next
293 * call, taking into account its current read position.
294 */
295 if (list->pos == req->actual) {
296 kfree(list);
297
298 req->length = hidg->report_length;
299 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
300 if (ret < 0) {
301 free_ep_req(hidg->out_ep, req);
302 return ret;
303 }
304 } else {
305 spin_lock_irqsave(&hidg->read_spinlock, flags);
306 list_add(&list->list, &hidg->completed_out_req);
307 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
308
309 wake_up(&hidg->read_queue);
310 }
311
312 return count;
313}
314
315static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
316{
317 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
318 unsigned long flags;
319
320 if (req->status != 0) {
321 ERROR(hidg->func.config->cdev,
322 "End Point Request ERROR: %d\n", req->status);
323 }
324
325 spin_lock_irqsave(&hidg->write_spinlock, flags);
326 hidg->write_pending = 0;
327 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
328 wake_up(&hidg->write_queue);
329}
330
331static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
332 size_t count, loff_t *offp)
333{
334 struct f_hidg *hidg = file->private_data;
335 struct usb_request *req;
336 unsigned long flags;
337 ssize_t status = -ENOMEM;
338
339 spin_lock_irqsave(&hidg->write_spinlock, flags);
340
341#define WRITE_COND (!hidg->write_pending)
342try_again:
343 /* write queue */
344 while (!WRITE_COND) {
345 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
346 if (file->f_flags & O_NONBLOCK)
347 return -EAGAIN;
348
349 if (wait_event_interruptible_exclusive(
350 hidg->write_queue, WRITE_COND))
351 return -ERESTARTSYS;
352
353 spin_lock_irqsave(&hidg->write_spinlock, flags);
354 }
355
356 hidg->write_pending = 1;
357 req = hidg->req;
358 count = min_t(unsigned, count, hidg->report_length);
359
360 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
361 status = copy_from_user(req->buf, buffer, count);
362
363 if (status != 0) {
364 ERROR(hidg->func.config->cdev,
365 "copy_from_user error\n");
366 status = -EINVAL;
367 goto release_write_pending;
368 }
369
370 spin_lock_irqsave(&hidg->write_spinlock, flags);
371
372 /* when our function has been disabled by host */
373 if (!hidg->req) {
374 free_ep_req(hidg->in_ep, req);
375 /*
376 * TODO
377 * Should we fail with error here?
378 */
379 goto try_again;
380 }
381
382 req->status = 0;
383 req->zero = 0;
384 req->length = count;
385 req->complete = f_hidg_req_complete;
386 req->context = hidg;
387
388 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
389
390 status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
391 if (status < 0) {
392 ERROR(hidg->func.config->cdev,
393 "usb_ep_queue error on int endpoint %zd\n", status);
394 goto release_write_pending;
395 } else {
396 status = count;
397 }
398
399 return status;
400release_write_pending:
401 spin_lock_irqsave(&hidg->write_spinlock, flags);
402 hidg->write_pending = 0;
403 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
404
405 wake_up(&hidg->write_queue);
406
407 return status;
408}
409
410static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
411{
412 struct f_hidg *hidg = file->private_data;
413 __poll_t ret = 0;
414
415 poll_wait(file, &hidg->read_queue, wait);
416 poll_wait(file, &hidg->write_queue, wait);
417
418 if (WRITE_COND)
419 ret |= EPOLLOUT | EPOLLWRNORM;
420
421 if (READ_COND)
422 ret |= EPOLLIN | EPOLLRDNORM;
423
424 return ret;
425}
426
427#undef WRITE_COND
428#undef READ_COND
429
430static int f_hidg_release(struct inode *inode, struct file *fd)
431{
432 fd->private_data = NULL;
433 return 0;
434}
435
436static int f_hidg_open(struct inode *inode, struct file *fd)
437{
438 struct f_hidg *hidg =
439 container_of(inode->i_cdev, struct f_hidg, cdev);
440
441 fd->private_data = hidg;
442
443 return 0;
444}
445
446/*-------------------------------------------------------------------------*/
447/* usb_function */
448
449static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
450 unsigned length)
451{
452 return alloc_ep_req(ep, length);
453}
454
455static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
456{
457 struct f_hidg *hidg = (struct f_hidg *) req->context;
458 struct usb_composite_dev *cdev = hidg->func.config->cdev;
459 struct f_hidg_req_list *req_list;
460 unsigned long flags;
461
462 switch (req->status) {
463 case 0:
464 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
465 if (!req_list) {
466 ERROR(cdev, "Unable to allocate mem for req_list\n");
467 goto free_req;
468 }
469
470 req_list->req = req;
471
472 spin_lock_irqsave(&hidg->read_spinlock, flags);
473 list_add_tail(&req_list->list, &hidg->completed_out_req);
474 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
475
476 wake_up(&hidg->read_queue);
477 break;
478 default:
479 ERROR(cdev, "Set report failed %d\n", req->status);
480 fallthrough;
481 case -ECONNABORTED: /* hardware forced ep reset */
482 case -ECONNRESET: /* request dequeued */
483 case -ESHUTDOWN: /* disconnect from host */
484free_req:
485 free_ep_req(ep, req);
486 return;
487 }
488}
489
490static int hidg_setup(struct usb_function *f,
491 const struct usb_ctrlrequest *ctrl)
492{
493 struct f_hidg *hidg = func_to_hidg(f);
494 struct usb_composite_dev *cdev = f->config->cdev;
495 struct usb_request *req = cdev->req;
496 int status = 0;
497 __u16 value, length;
498
499 value = __le16_to_cpu(ctrl->wValue);
500 length = __le16_to_cpu(ctrl->wLength);
501
502 VDBG(cdev,
503 "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
504 __func__, ctrl->bRequestType, ctrl->bRequest, value);
505
506 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
507 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
508 | HID_REQ_GET_REPORT):
509 VDBG(cdev, "get_report\n");
510
511 /* send an empty report */
512 length = min_t(unsigned, length, hidg->report_length);
513 memset(req->buf, 0x0, length);
514
515 goto respond;
516 break;
517
518 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
519 | HID_REQ_GET_PROTOCOL):
520 VDBG(cdev, "get_protocol\n");
521 length = min_t(unsigned int, length, 1);
522 ((u8 *) req->buf)[0] = hidg->protocol;
523 goto respond;
524 break;
525
526 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
527 | HID_REQ_SET_REPORT):
528 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
529 goto stall;
530 break;
531
532 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
533 | HID_REQ_SET_PROTOCOL):
534 VDBG(cdev, "set_protocol\n");
535 if (value > HID_REPORT_PROTOCOL)
536 goto stall;
537 length = 0;
538 /*
539 * We assume that programs implementing the Boot protocol
540 * are also compatible with the Report Protocol
541 */
542 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
543 hidg->protocol = value;
544 goto respond;
545 }
546 goto stall;
547 break;
548
549 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
550 | USB_REQ_GET_DESCRIPTOR):
551 switch (value >> 8) {
552 case HID_DT_HID:
553 {
554 struct hid_descriptor hidg_desc_copy = hidg_desc;
555
556 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
557 hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
558 hidg_desc_copy.desc[0].wDescriptorLength =
559 cpu_to_le16(hidg->report_desc_length);
560
561 length = min_t(unsigned short, length,
562 hidg_desc_copy.bLength);
563 memcpy(req->buf, &hidg_desc_copy, length);
564 goto respond;
565 break;
566 }
567 case HID_DT_REPORT:
568 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
569 length = min_t(unsigned short, length,
570 hidg->report_desc_length);
571 memcpy(req->buf, hidg->report_desc, length);
572 goto respond;
573 break;
574
575 default:
576 VDBG(cdev, "Unknown descriptor request 0x%x\n",
577 value >> 8);
578 goto stall;
579 break;
580 }
581 break;
582
583 default:
584 VDBG(cdev, "Unknown request 0x%x\n",
585 ctrl->bRequest);
586 goto stall;
587 break;
588 }
589
590stall:
591 return -EOPNOTSUPP;
592
593respond:
594 req->zero = 0;
595 req->length = length;
596 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
597 if (status < 0)
598 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
599 return status;
600}
601
602static void hidg_disable(struct usb_function *f)
603{
604 struct f_hidg *hidg = func_to_hidg(f);
605 struct f_hidg_req_list *list, *next;
606 unsigned long flags;
607
608 usb_ep_disable(hidg->in_ep);
609 usb_ep_disable(hidg->out_ep);
610
611 spin_lock_irqsave(&hidg->read_spinlock, flags);
612 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
613 free_ep_req(hidg->out_ep, list->req);
614 list_del(&list->list);
615 kfree(list);
616 }
617 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
618
619 spin_lock_irqsave(&hidg->write_spinlock, flags);
620 if (!hidg->write_pending) {
621 free_ep_req(hidg->in_ep, hidg->req);
622 hidg->write_pending = 1;
623 }
624
625 hidg->req = NULL;
626 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
627}
628
629static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
630{
631 struct usb_composite_dev *cdev = f->config->cdev;
632 struct f_hidg *hidg = func_to_hidg(f);
633 struct usb_request *req_in = NULL;
634 unsigned long flags;
635 int i, status = 0;
636
637 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
638
639 if (hidg->in_ep != NULL) {
640 /* restart endpoint */
641 usb_ep_disable(hidg->in_ep);
642
643 status = config_ep_by_speed(f->config->cdev->gadget, f,
644 hidg->in_ep);
645 if (status) {
646 ERROR(cdev, "config_ep_by_speed FAILED!\n");
647 goto fail;
648 }
649 status = usb_ep_enable(hidg->in_ep);
650 if (status < 0) {
651 ERROR(cdev, "Enable IN endpoint FAILED!\n");
652 goto fail;
653 }
654 hidg->in_ep->driver_data = hidg;
655
656 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
657 if (!req_in) {
658 status = -ENOMEM;
659 goto disable_ep_in;
660 }
661 }
662
663
664 if (hidg->out_ep != NULL) {
665 /* restart endpoint */
666 usb_ep_disable(hidg->out_ep);
667
668 status = config_ep_by_speed(f->config->cdev->gadget, f,
669 hidg->out_ep);
670 if (status) {
671 ERROR(cdev, "config_ep_by_speed FAILED!\n");
672 goto free_req_in;
673 }
674 status = usb_ep_enable(hidg->out_ep);
675 if (status < 0) {
676 ERROR(cdev, "Enable OUT endpoint FAILED!\n");
677 goto free_req_in;
678 }
679 hidg->out_ep->driver_data = hidg;
680
681 /*
682 * allocate a bunch of read buffers and queue them all at once.
683 */
684 for (i = 0; i < hidg->qlen && status == 0; i++) {
685 struct usb_request *req =
686 hidg_alloc_ep_req(hidg->out_ep,
687 hidg->report_length);
688 if (req) {
689 req->complete = hidg_set_report_complete;
690 req->context = hidg;
691 status = usb_ep_queue(hidg->out_ep, req,
692 GFP_ATOMIC);
693 if (status) {
694 ERROR(cdev, "%s queue req --> %d\n",
695 hidg->out_ep->name, status);
696 free_ep_req(hidg->out_ep, req);
697 }
698 } else {
699 status = -ENOMEM;
700 goto disable_out_ep;
701 }
702 }
703 }
704
705 if (hidg->in_ep != NULL) {
706 spin_lock_irqsave(&hidg->write_spinlock, flags);
707 hidg->req = req_in;
708 hidg->write_pending = 0;
709 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
710
711 wake_up(&hidg->write_queue);
712 }
713 return 0;
714disable_out_ep:
715 usb_ep_disable(hidg->out_ep);
716free_req_in:
717 if (req_in)
718 free_ep_req(hidg->in_ep, req_in);
719
720disable_ep_in:
721 if (hidg->in_ep)
722 usb_ep_disable(hidg->in_ep);
723
724fail:
725 return status;
726}
727
728static const struct file_operations f_hidg_fops = {
729 .owner = THIS_MODULE,
730 .open = f_hidg_open,
731 .release = f_hidg_release,
732 .write = f_hidg_write,
733 .read = f_hidg_read,
734 .poll = f_hidg_poll,
735 .llseek = noop_llseek,
736};
737
738static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
739{
740 struct usb_ep *ep;
741 struct f_hidg *hidg = func_to_hidg(f);
742 struct usb_string *us;
743 struct device *device;
744 int status;
745 dev_t dev;
746
747 /* maybe allocate device-global string IDs, and patch descriptors */
748 us = usb_gstrings_attach(c->cdev, ct_func_strings,
749 ARRAY_SIZE(ct_func_string_defs));
750 if (IS_ERR(us))
751 return PTR_ERR(us);
752 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
753
754 /* allocate instance-specific interface IDs, and patch descriptors */
755 status = usb_interface_id(c, f);
756 if (status < 0)
757 goto fail;
758 hidg_interface_desc.bInterfaceNumber = status;
759
760 /* allocate instance-specific endpoints */
761 status = -ENODEV;
762 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
763 if (!ep)
764 goto fail;
765 hidg->in_ep = ep;
766
767 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
768 if (!ep)
769 goto fail;
770 hidg->out_ep = ep;
771
772 /* set descriptor dynamic values */
773 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
774 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
775 hidg->protocol = HID_REPORT_PROTOCOL;
776 hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
777 hidg_ss_in_comp_desc.wBytesPerInterval =
778 cpu_to_le16(hidg->report_length);
779 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
780 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
781 hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
782 hidg_ss_out_comp_desc.wBytesPerInterval =
783 cpu_to_le16(hidg->report_length);
784 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
785 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
786 /*
787 * We can use hidg_desc struct here but we should not relay
788 * that its content won't change after returning from this function.
789 */
790 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
791 hidg_desc.desc[0].wDescriptorLength =
792 cpu_to_le16(hidg->report_desc_length);
793
794 hidg_hs_in_ep_desc.bEndpointAddress =
795 hidg_fs_in_ep_desc.bEndpointAddress;
796 hidg_hs_out_ep_desc.bEndpointAddress =
797 hidg_fs_out_ep_desc.bEndpointAddress;
798
799 hidg_ss_in_ep_desc.bEndpointAddress =
800 hidg_fs_in_ep_desc.bEndpointAddress;
801 hidg_ss_out_ep_desc.bEndpointAddress =
802 hidg_fs_out_ep_desc.bEndpointAddress;
803
804 status = usb_assign_descriptors(f, hidg_fs_descriptors,
805 hidg_hs_descriptors, hidg_ss_descriptors, NULL);
806 if (status)
807 goto fail;
808
809 spin_lock_init(&hidg->write_spinlock);
810 hidg->write_pending = 1;
811 hidg->req = NULL;
812 spin_lock_init(&hidg->read_spinlock);
813 init_waitqueue_head(&hidg->write_queue);
814 init_waitqueue_head(&hidg->read_queue);
815 INIT_LIST_HEAD(&hidg->completed_out_req);
816
817 /* create char device */
818 cdev_init(&hidg->cdev, &f_hidg_fops);
819 dev = MKDEV(major, hidg->minor);
820 status = cdev_add(&hidg->cdev, dev, 1);
821 if (status)
822 goto fail_free_descs;
823
824 device = device_create(hidg_class, NULL, dev, NULL,
825 "%s%d", "hidg", hidg->minor);
826 if (IS_ERR(device)) {
827 status = PTR_ERR(device);
828 goto del;
829 }
830
831 return 0;
832del:
833 cdev_del(&hidg->cdev);
834fail_free_descs:
835 usb_free_all_descriptors(f);
836fail:
837 ERROR(f->config->cdev, "hidg_bind FAILED\n");
838 if (hidg->req != NULL)
839 free_ep_req(hidg->in_ep, hidg->req);
840
841 return status;
842}
843
844static inline int hidg_get_minor(void)
845{
846 int ret;
847
848 ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
849 if (ret >= HIDG_MINORS) {
850 ida_simple_remove(&hidg_ida, ret);
851 ret = -ENODEV;
852 }
853
854 return ret;
855}
856
857static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
858{
859 return container_of(to_config_group(item), struct f_hid_opts,
860 func_inst.group);
861}
862
863static void hid_attr_release(struct config_item *item)
864{
865 struct f_hid_opts *opts = to_f_hid_opts(item);
866
867 usb_put_function_instance(&opts->func_inst);
868}
869
870static struct configfs_item_operations hidg_item_ops = {
871 .release = hid_attr_release,
872};
873
874#define F_HID_OPT(name, prec, limit) \
875static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
876{ \
877 struct f_hid_opts *opts = to_f_hid_opts(item); \
878 int result; \
879 \
880 mutex_lock(&opts->lock); \
881 result = sprintf(page, "%d\n", opts->name); \
882 mutex_unlock(&opts->lock); \
883 \
884 return result; \
885} \
886 \
887static ssize_t f_hid_opts_##name##_store(struct config_item *item, \
888 const char *page, size_t len) \
889{ \
890 struct f_hid_opts *opts = to_f_hid_opts(item); \
891 int ret; \
892 u##prec num; \
893 \
894 mutex_lock(&opts->lock); \
895 if (opts->refcnt) { \
896 ret = -EBUSY; \
897 goto end; \
898 } \
899 \
900 ret = kstrtou##prec(page, 0, &num); \
901 if (ret) \
902 goto end; \
903 \
904 if (num > limit) { \
905 ret = -EINVAL; \
906 goto end; \
907 } \
908 opts->name = num; \
909 ret = len; \
910 \
911end: \
912 mutex_unlock(&opts->lock); \
913 return ret; \
914} \
915 \
916CONFIGFS_ATTR(f_hid_opts_, name)
917
918F_HID_OPT(subclass, 8, 255);
919F_HID_OPT(protocol, 8, 255);
920F_HID_OPT(report_length, 16, 65535);
921
922static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
923{
924 struct f_hid_opts *opts = to_f_hid_opts(item);
925 int result;
926
927 mutex_lock(&opts->lock);
928 result = opts->report_desc_length;
929 memcpy(page, opts->report_desc, opts->report_desc_length);
930 mutex_unlock(&opts->lock);
931
932 return result;
933}
934
935static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
936 const char *page, size_t len)
937{
938 struct f_hid_opts *opts = to_f_hid_opts(item);
939 int ret = -EBUSY;
940 char *d;
941
942 mutex_lock(&opts->lock);
943
944 if (opts->refcnt)
945 goto end;
946 if (len > PAGE_SIZE) {
947 ret = -ENOSPC;
948 goto end;
949 }
950 d = kmemdup(page, len, GFP_KERNEL);
951 if (!d) {
952 ret = -ENOMEM;
953 goto end;
954 }
955 kfree(opts->report_desc);
956 opts->report_desc = d;
957 opts->report_desc_length = len;
958 opts->report_desc_alloc = true;
959 ret = len;
960end:
961 mutex_unlock(&opts->lock);
962 return ret;
963}
964
965CONFIGFS_ATTR(f_hid_opts_, report_desc);
966
967static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
968{
969 struct f_hid_opts *opts = to_f_hid_opts(item);
970
971 return sprintf(page, "%d:%d\n", major, opts->minor);
972}
973
974CONFIGFS_ATTR_RO(f_hid_opts_, dev);
975
976static struct configfs_attribute *hid_attrs[] = {
977 &f_hid_opts_attr_subclass,
978 &f_hid_opts_attr_protocol,
979 &f_hid_opts_attr_report_length,
980 &f_hid_opts_attr_report_desc,
981 &f_hid_opts_attr_dev,
982 NULL,
983};
984
985static const struct config_item_type hid_func_type = {
986 .ct_item_ops = &hidg_item_ops,
987 .ct_attrs = hid_attrs,
988 .ct_owner = THIS_MODULE,
989};
990
991static inline void hidg_put_minor(int minor)
992{
993 ida_simple_remove(&hidg_ida, minor);
994}
995
996static void hidg_free_inst(struct usb_function_instance *f)
997{
998 struct f_hid_opts *opts;
999
1000 opts = container_of(f, struct f_hid_opts, func_inst);
1001
1002 mutex_lock(&hidg_ida_lock);
1003
1004 hidg_put_minor(opts->minor);
1005 if (ida_is_empty(&hidg_ida))
1006 ghid_cleanup();
1007
1008 mutex_unlock(&hidg_ida_lock);
1009
1010 if (opts->report_desc_alloc)
1011 kfree(opts->report_desc);
1012
1013 kfree(opts);
1014}
1015
1016static struct usb_function_instance *hidg_alloc_inst(void)
1017{
1018 struct f_hid_opts *opts;
1019 struct usb_function_instance *ret;
1020 int status = 0;
1021
1022 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1023 if (!opts)
1024 return ERR_PTR(-ENOMEM);
1025 mutex_init(&opts->lock);
1026 opts->func_inst.free_func_inst = hidg_free_inst;
1027 ret = &opts->func_inst;
1028
1029 mutex_lock(&hidg_ida_lock);
1030
1031 if (ida_is_empty(&hidg_ida)) {
1032 status = ghid_setup(NULL, HIDG_MINORS);
1033 if (status) {
1034 ret = ERR_PTR(status);
1035 kfree(opts);
1036 goto unlock;
1037 }
1038 }
1039
1040 opts->minor = hidg_get_minor();
1041 if (opts->minor < 0) {
1042 ret = ERR_PTR(opts->minor);
1043 kfree(opts);
1044 if (ida_is_empty(&hidg_ida))
1045 ghid_cleanup();
1046 goto unlock;
1047 }
1048 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1049
1050unlock:
1051 mutex_unlock(&hidg_ida_lock);
1052 return ret;
1053}
1054
1055static void hidg_free(struct usb_function *f)
1056{
1057 struct f_hidg *hidg;
1058 struct f_hid_opts *opts;
1059
1060 hidg = func_to_hidg(f);
1061 opts = container_of(f->fi, struct f_hid_opts, func_inst);
1062 kfree(hidg->report_desc);
1063 kfree(hidg);
1064 mutex_lock(&opts->lock);
1065 --opts->refcnt;
1066 mutex_unlock(&opts->lock);
1067}
1068
1069static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1070{
1071 struct f_hidg *hidg = func_to_hidg(f);
1072
1073 device_destroy(hidg_class, MKDEV(major, hidg->minor));
1074 cdev_del(&hidg->cdev);
1075
1076 usb_free_all_descriptors(f);
1077}
1078
1079static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1080{
1081 struct f_hidg *hidg;
1082 struct f_hid_opts *opts;
1083
1084 /* allocate and initialize one new instance */
1085 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1086 if (!hidg)
1087 return ERR_PTR(-ENOMEM);
1088
1089 opts = container_of(fi, struct f_hid_opts, func_inst);
1090
1091 mutex_lock(&opts->lock);
1092 ++opts->refcnt;
1093
1094 hidg->minor = opts->minor;
1095 hidg->bInterfaceSubClass = opts->subclass;
1096 hidg->bInterfaceProtocol = opts->protocol;
1097 hidg->report_length = opts->report_length;
1098 hidg->report_desc_length = opts->report_desc_length;
1099 if (opts->report_desc) {
1100 hidg->report_desc = kmemdup(opts->report_desc,
1101 opts->report_desc_length,
1102 GFP_KERNEL);
1103 if (!hidg->report_desc) {
1104 kfree(hidg);
1105 mutex_unlock(&opts->lock);
1106 return ERR_PTR(-ENOMEM);
1107 }
1108 }
1109
1110 mutex_unlock(&opts->lock);
1111
1112 hidg->func.name = "hid";
1113 hidg->func.bind = hidg_bind;
1114 hidg->func.unbind = hidg_unbind;
1115 hidg->func.set_alt = hidg_set_alt;
1116 hidg->func.disable = hidg_disable;
1117 hidg->func.setup = hidg_setup;
1118 hidg->func.free_func = hidg_free;
1119
1120 /* this could me made configurable at some point */
1121 hidg->qlen = 4;
1122
1123 return &hidg->func;
1124}
1125
1126DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1127MODULE_LICENSE("GPL");
1128MODULE_AUTHOR("Fabien Chouteau");
1129
1130int ghid_setup(struct usb_gadget *g, int count)
1131{
1132 int status;
1133 dev_t dev;
1134
1135 hidg_class = class_create(THIS_MODULE, "hidg");
1136 if (IS_ERR(hidg_class)) {
1137 status = PTR_ERR(hidg_class);
1138 hidg_class = NULL;
1139 return status;
1140 }
1141
1142 status = alloc_chrdev_region(&dev, 0, count, "hidg");
1143 if (status) {
1144 class_destroy(hidg_class);
1145 hidg_class = NULL;
1146 return status;
1147 }
1148
1149 major = MAJOR(dev);
1150 minors = count;
1151
1152 return 0;
1153}
1154
1155void ghid_cleanup(void)
1156{
1157 if (major) {
1158 unregister_chrdev_region(MKDEV(major, 0), minors);
1159 major = minors = 0;
1160 }
1161
1162 class_destroy(hidg_class);
1163 hidg_class = NULL;
1164}