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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/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}