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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 char idle;
45 unsigned short report_desc_length;
46 char *report_desc;
47 unsigned short report_length;
48
49 /* recv report */
50 struct list_head completed_out_req;
51 spinlock_t read_spinlock;
52 wait_queue_head_t read_queue;
53 unsigned int qlen;
54
55 /* send report */
56 spinlock_t write_spinlock;
57 bool write_pending;
58 wait_queue_head_t write_queue;
59 struct usb_request *req;
60
61 int minor;
62 struct cdev cdev;
63 struct usb_function func;
64
65 struct usb_ep *in_ep;
66 struct usb_ep *out_ep;
67};
68
69static inline struct f_hidg *func_to_hidg(struct usb_function *f)
70{
71 return container_of(f, struct f_hidg, func);
72}
73
74/*-------------------------------------------------------------------------*/
75/* Static descriptors */
76
77static struct usb_interface_descriptor hidg_interface_desc = {
78 .bLength = sizeof hidg_interface_desc,
79 .bDescriptorType = USB_DT_INTERFACE,
80 /* .bInterfaceNumber = DYNAMIC */
81 .bAlternateSetting = 0,
82 .bNumEndpoints = 2,
83 .bInterfaceClass = USB_CLASS_HID,
84 /* .bInterfaceSubClass = DYNAMIC */
85 /* .bInterfaceProtocol = DYNAMIC */
86 /* .iInterface = DYNAMIC */
87};
88
89static struct hid_descriptor hidg_desc = {
90 .bLength = sizeof hidg_desc,
91 .bDescriptorType = HID_DT_HID,
92 .bcdHID = cpu_to_le16(0x0101),
93 .bCountryCode = 0x00,
94 .bNumDescriptors = 0x1,
95 /*.desc[0].bDescriptorType = DYNAMIC */
96 /*.desc[0].wDescriptorLenght = DYNAMIC */
97};
98
99/* Super-Speed Support */
100
101static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
102 .bLength = USB_DT_ENDPOINT_SIZE,
103 .bDescriptorType = USB_DT_ENDPOINT,
104 .bEndpointAddress = USB_DIR_IN,
105 .bmAttributes = USB_ENDPOINT_XFER_INT,
106 /*.wMaxPacketSize = DYNAMIC */
107 .bInterval = 4, /* FIXME: Add this field in the
108 * HID gadget configuration?
109 * (struct hidg_func_descriptor)
110 */
111};
112
113static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
114 .bLength = sizeof(hidg_ss_in_comp_desc),
115 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
116
117 /* .bMaxBurst = 0, */
118 /* .bmAttributes = 0, */
119 /* .wBytesPerInterval = DYNAMIC */
120};
121
122static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
123 .bLength = USB_DT_ENDPOINT_SIZE,
124 .bDescriptorType = USB_DT_ENDPOINT,
125 .bEndpointAddress = USB_DIR_OUT,
126 .bmAttributes = USB_ENDPOINT_XFER_INT,
127 /*.wMaxPacketSize = DYNAMIC */
128 .bInterval = 4, /* FIXME: Add this field in the
129 * HID gadget configuration?
130 * (struct hidg_func_descriptor)
131 */
132};
133
134static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
135 .bLength = sizeof(hidg_ss_out_comp_desc),
136 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
137
138 /* .bMaxBurst = 0, */
139 /* .bmAttributes = 0, */
140 /* .wBytesPerInterval = DYNAMIC */
141};
142
143static struct usb_descriptor_header *hidg_ss_descriptors[] = {
144 (struct usb_descriptor_header *)&hidg_interface_desc,
145 (struct usb_descriptor_header *)&hidg_desc,
146 (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
147 (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
148 (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
149 (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
150 NULL,
151};
152
153/* High-Speed Support */
154
155static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
156 .bLength = USB_DT_ENDPOINT_SIZE,
157 .bDescriptorType = USB_DT_ENDPOINT,
158 .bEndpointAddress = USB_DIR_IN,
159 .bmAttributes = USB_ENDPOINT_XFER_INT,
160 /*.wMaxPacketSize = DYNAMIC */
161 .bInterval = 4, /* FIXME: Add this field in the
162 * HID gadget configuration?
163 * (struct hidg_func_descriptor)
164 */
165};
166
167static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
168 .bLength = USB_DT_ENDPOINT_SIZE,
169 .bDescriptorType = USB_DT_ENDPOINT,
170 .bEndpointAddress = USB_DIR_OUT,
171 .bmAttributes = USB_ENDPOINT_XFER_INT,
172 /*.wMaxPacketSize = DYNAMIC */
173 .bInterval = 4, /* FIXME: Add this field in the
174 * HID gadget configuration?
175 * (struct hidg_func_descriptor)
176 */
177};
178
179static struct usb_descriptor_header *hidg_hs_descriptors[] = {
180 (struct usb_descriptor_header *)&hidg_interface_desc,
181 (struct usb_descriptor_header *)&hidg_desc,
182 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
183 (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
184 NULL,
185};
186
187/* Full-Speed Support */
188
189static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
190 .bLength = USB_DT_ENDPOINT_SIZE,
191 .bDescriptorType = USB_DT_ENDPOINT,
192 .bEndpointAddress = USB_DIR_IN,
193 .bmAttributes = USB_ENDPOINT_XFER_INT,
194 /*.wMaxPacketSize = DYNAMIC */
195 .bInterval = 10, /* FIXME: Add this field in the
196 * HID gadget configuration?
197 * (struct hidg_func_descriptor)
198 */
199};
200
201static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
202 .bLength = USB_DT_ENDPOINT_SIZE,
203 .bDescriptorType = USB_DT_ENDPOINT,
204 .bEndpointAddress = USB_DIR_OUT,
205 .bmAttributes = USB_ENDPOINT_XFER_INT,
206 /*.wMaxPacketSize = DYNAMIC */
207 .bInterval = 10, /* FIXME: Add this field in the
208 * HID gadget configuration?
209 * (struct hidg_func_descriptor)
210 */
211};
212
213static struct usb_descriptor_header *hidg_fs_descriptors[] = {
214 (struct usb_descriptor_header *)&hidg_interface_desc,
215 (struct usb_descriptor_header *)&hidg_desc,
216 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
217 (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
218 NULL,
219};
220
221/*-------------------------------------------------------------------------*/
222/* Strings */
223
224#define CT_FUNC_HID_IDX 0
225
226static struct usb_string ct_func_string_defs[] = {
227 [CT_FUNC_HID_IDX].s = "HID Interface",
228 {}, /* end of list */
229};
230
231static struct usb_gadget_strings ct_func_string_table = {
232 .language = 0x0409, /* en-US */
233 .strings = ct_func_string_defs,
234};
235
236static struct usb_gadget_strings *ct_func_strings[] = {
237 &ct_func_string_table,
238 NULL,
239};
240
241/*-------------------------------------------------------------------------*/
242/* Char Device */
243
244static ssize_t f_hidg_read(struct file *file, char __user *buffer,
245 size_t count, loff_t *ptr)
246{
247 struct f_hidg *hidg = file->private_data;
248 struct f_hidg_req_list *list;
249 struct usb_request *req;
250 unsigned long flags;
251 int ret;
252
253 if (!count)
254 return 0;
255
256 spin_lock_irqsave(&hidg->read_spinlock, flags);
257
258#define READ_COND (!list_empty(&hidg->completed_out_req))
259
260 /* wait for at least one buffer to complete */
261 while (!READ_COND) {
262 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
263 if (file->f_flags & O_NONBLOCK)
264 return -EAGAIN;
265
266 if (wait_event_interruptible(hidg->read_queue, READ_COND))
267 return -ERESTARTSYS;
268
269 spin_lock_irqsave(&hidg->read_spinlock, flags);
270 }
271
272 /* pick the first one */
273 list = list_first_entry(&hidg->completed_out_req,
274 struct f_hidg_req_list, list);
275
276 /*
277 * Remove this from list to protect it from beign free()
278 * while host disables our function
279 */
280 list_del(&list->list);
281
282 req = list->req;
283 count = min_t(unsigned int, count, req->actual - list->pos);
284 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
285
286 /* copy to user outside spinlock */
287 count -= copy_to_user(buffer, req->buf + list->pos, count);
288 list->pos += count;
289
290 /*
291 * if this request is completely handled and transfered to
292 * userspace, remove its entry from the list and requeue it
293 * again. Otherwise, we will revisit it again upon the next
294 * call, taking into account its current read position.
295 */
296 if (list->pos == req->actual) {
297 kfree(list);
298
299 req->length = hidg->report_length;
300 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
301 if (ret < 0) {
302 free_ep_req(hidg->out_ep, req);
303 return ret;
304 }
305 } else {
306 spin_lock_irqsave(&hidg->read_spinlock, flags);
307 list_add(&list->list, &hidg->completed_out_req);
308 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
309
310 wake_up(&hidg->read_queue);
311 }
312
313 return count;
314}
315
316static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
317{
318 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
319 unsigned long flags;
320
321 if (req->status != 0) {
322 ERROR(hidg->func.config->cdev,
323 "End Point Request ERROR: %d\n", req->status);
324 }
325
326 spin_lock_irqsave(&hidg->write_spinlock, flags);
327 hidg->write_pending = 0;
328 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
329 wake_up(&hidg->write_queue);
330}
331
332static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
333 size_t count, loff_t *offp)
334{
335 struct f_hidg *hidg = file->private_data;
336 struct usb_request *req;
337 unsigned long flags;
338 ssize_t status = -ENOMEM;
339
340 spin_lock_irqsave(&hidg->write_spinlock, flags);
341
342 if (!hidg->req) {
343 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
344 return -ESHUTDOWN;
345 }
346
347#define WRITE_COND (!hidg->write_pending)
348try_again:
349 /* write queue */
350 while (!WRITE_COND) {
351 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
352 if (file->f_flags & O_NONBLOCK)
353 return -EAGAIN;
354
355 if (wait_event_interruptible_exclusive(
356 hidg->write_queue, WRITE_COND))
357 return -ERESTARTSYS;
358
359 spin_lock_irqsave(&hidg->write_spinlock, flags);
360 }
361
362 hidg->write_pending = 1;
363 req = hidg->req;
364 count = min_t(unsigned, count, hidg->report_length);
365
366 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
367
368 if (!req) {
369 ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
370 status = -ESHUTDOWN;
371 goto release_write_pending;
372 }
373
374 status = copy_from_user(req->buf, buffer, count);
375 if (status != 0) {
376 ERROR(hidg->func.config->cdev,
377 "copy_from_user error\n");
378 status = -EINVAL;
379 goto release_write_pending;
380 }
381
382 spin_lock_irqsave(&hidg->write_spinlock, flags);
383
384 /* when our function has been disabled by host */
385 if (!hidg->req) {
386 free_ep_req(hidg->in_ep, req);
387 /*
388 * TODO
389 * Should we fail with error here?
390 */
391 goto try_again;
392 }
393
394 req->status = 0;
395 req->zero = 0;
396 req->length = count;
397 req->complete = f_hidg_req_complete;
398 req->context = hidg;
399
400 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
401
402 if (!hidg->in_ep->enabled) {
403 ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
404 status = -ESHUTDOWN;
405 goto release_write_pending;
406 }
407
408 status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
409 if (status < 0)
410 goto release_write_pending;
411 else
412 status = count;
413
414 return status;
415release_write_pending:
416 spin_lock_irqsave(&hidg->write_spinlock, flags);
417 hidg->write_pending = 0;
418 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
419
420 wake_up(&hidg->write_queue);
421
422 return status;
423}
424
425static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
426{
427 struct f_hidg *hidg = file->private_data;
428 __poll_t ret = 0;
429
430 poll_wait(file, &hidg->read_queue, wait);
431 poll_wait(file, &hidg->write_queue, wait);
432
433 if (WRITE_COND)
434 ret |= EPOLLOUT | EPOLLWRNORM;
435
436 if (READ_COND)
437 ret |= EPOLLIN | EPOLLRDNORM;
438
439 return ret;
440}
441
442#undef WRITE_COND
443#undef READ_COND
444
445static int f_hidg_release(struct inode *inode, struct file *fd)
446{
447 fd->private_data = NULL;
448 return 0;
449}
450
451static int f_hidg_open(struct inode *inode, struct file *fd)
452{
453 struct f_hidg *hidg =
454 container_of(inode->i_cdev, struct f_hidg, cdev);
455
456 fd->private_data = hidg;
457
458 return 0;
459}
460
461/*-------------------------------------------------------------------------*/
462/* usb_function */
463
464static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
465 unsigned length)
466{
467 return alloc_ep_req(ep, length);
468}
469
470static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
471{
472 struct f_hidg *hidg = (struct f_hidg *) req->context;
473 struct usb_composite_dev *cdev = hidg->func.config->cdev;
474 struct f_hidg_req_list *req_list;
475 unsigned long flags;
476
477 switch (req->status) {
478 case 0:
479 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
480 if (!req_list) {
481 ERROR(cdev, "Unable to allocate mem for req_list\n");
482 goto free_req;
483 }
484
485 req_list->req = req;
486
487 spin_lock_irqsave(&hidg->read_spinlock, flags);
488 list_add_tail(&req_list->list, &hidg->completed_out_req);
489 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
490
491 wake_up(&hidg->read_queue);
492 break;
493 default:
494 ERROR(cdev, "Set report failed %d\n", req->status);
495 fallthrough;
496 case -ECONNABORTED: /* hardware forced ep reset */
497 case -ECONNRESET: /* request dequeued */
498 case -ESHUTDOWN: /* disconnect from host */
499free_req:
500 free_ep_req(ep, req);
501 return;
502 }
503}
504
505static int hidg_setup(struct usb_function *f,
506 const struct usb_ctrlrequest *ctrl)
507{
508 struct f_hidg *hidg = func_to_hidg(f);
509 struct usb_composite_dev *cdev = f->config->cdev;
510 struct usb_request *req = cdev->req;
511 int status = 0;
512 __u16 value, length;
513
514 value = __le16_to_cpu(ctrl->wValue);
515 length = __le16_to_cpu(ctrl->wLength);
516
517 VDBG(cdev,
518 "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
519 __func__, ctrl->bRequestType, ctrl->bRequest, value);
520
521 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
522 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
523 | HID_REQ_GET_REPORT):
524 VDBG(cdev, "get_report\n");
525
526 /* send an empty report */
527 length = min_t(unsigned, length, hidg->report_length);
528 memset(req->buf, 0x0, length);
529
530 goto respond;
531 break;
532
533 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
534 | HID_REQ_GET_PROTOCOL):
535 VDBG(cdev, "get_protocol\n");
536 length = min_t(unsigned int, length, 1);
537 ((u8 *) req->buf)[0] = hidg->protocol;
538 goto respond;
539 break;
540
541 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
542 | HID_REQ_GET_IDLE):
543 VDBG(cdev, "get_idle\n");
544 length = min_t(unsigned int, length, 1);
545 ((u8 *) req->buf)[0] = hidg->idle;
546 goto respond;
547 break;
548
549 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
550 | HID_REQ_SET_REPORT):
551 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
552 goto stall;
553 break;
554
555 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
556 | HID_REQ_SET_PROTOCOL):
557 VDBG(cdev, "set_protocol\n");
558 if (value > HID_REPORT_PROTOCOL)
559 goto stall;
560 length = 0;
561 /*
562 * We assume that programs implementing the Boot protocol
563 * are also compatible with the Report Protocol
564 */
565 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
566 hidg->protocol = value;
567 goto respond;
568 }
569 goto stall;
570 break;
571
572 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
573 | HID_REQ_SET_IDLE):
574 VDBG(cdev, "set_idle\n");
575 length = 0;
576 hidg->idle = value >> 8;
577 goto respond;
578 break;
579
580 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
581 | USB_REQ_GET_DESCRIPTOR):
582 switch (value >> 8) {
583 case HID_DT_HID:
584 {
585 struct hid_descriptor hidg_desc_copy = hidg_desc;
586
587 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
588 hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
589 hidg_desc_copy.desc[0].wDescriptorLength =
590 cpu_to_le16(hidg->report_desc_length);
591
592 length = min_t(unsigned short, length,
593 hidg_desc_copy.bLength);
594 memcpy(req->buf, &hidg_desc_copy, length);
595 goto respond;
596 break;
597 }
598 case HID_DT_REPORT:
599 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
600 length = min_t(unsigned short, length,
601 hidg->report_desc_length);
602 memcpy(req->buf, hidg->report_desc, length);
603 goto respond;
604 break;
605
606 default:
607 VDBG(cdev, "Unknown descriptor request 0x%x\n",
608 value >> 8);
609 goto stall;
610 break;
611 }
612 break;
613
614 default:
615 VDBG(cdev, "Unknown request 0x%x\n",
616 ctrl->bRequest);
617 goto stall;
618 break;
619 }
620
621stall:
622 return -EOPNOTSUPP;
623
624respond:
625 req->zero = 0;
626 req->length = length;
627 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
628 if (status < 0)
629 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
630 return status;
631}
632
633static void hidg_disable(struct usb_function *f)
634{
635 struct f_hidg *hidg = func_to_hidg(f);
636 struct f_hidg_req_list *list, *next;
637 unsigned long flags;
638
639 usb_ep_disable(hidg->in_ep);
640 usb_ep_disable(hidg->out_ep);
641
642 spin_lock_irqsave(&hidg->read_spinlock, flags);
643 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
644 free_ep_req(hidg->out_ep, list->req);
645 list_del(&list->list);
646 kfree(list);
647 }
648 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
649
650 spin_lock_irqsave(&hidg->write_spinlock, flags);
651 if (!hidg->write_pending) {
652 free_ep_req(hidg->in_ep, hidg->req);
653 hidg->write_pending = 1;
654 }
655
656 hidg->req = NULL;
657 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
658}
659
660static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
661{
662 struct usb_composite_dev *cdev = f->config->cdev;
663 struct f_hidg *hidg = func_to_hidg(f);
664 struct usb_request *req_in = NULL;
665 unsigned long flags;
666 int i, status = 0;
667
668 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
669
670 if (hidg->in_ep != NULL) {
671 /* restart endpoint */
672 usb_ep_disable(hidg->in_ep);
673
674 status = config_ep_by_speed(f->config->cdev->gadget, f,
675 hidg->in_ep);
676 if (status) {
677 ERROR(cdev, "config_ep_by_speed FAILED!\n");
678 goto fail;
679 }
680 status = usb_ep_enable(hidg->in_ep);
681 if (status < 0) {
682 ERROR(cdev, "Enable IN endpoint FAILED!\n");
683 goto fail;
684 }
685 hidg->in_ep->driver_data = hidg;
686
687 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
688 if (!req_in) {
689 status = -ENOMEM;
690 goto disable_ep_in;
691 }
692 }
693
694
695 if (hidg->out_ep != NULL) {
696 /* restart endpoint */
697 usb_ep_disable(hidg->out_ep);
698
699 status = config_ep_by_speed(f->config->cdev->gadget, f,
700 hidg->out_ep);
701 if (status) {
702 ERROR(cdev, "config_ep_by_speed FAILED!\n");
703 goto free_req_in;
704 }
705 status = usb_ep_enable(hidg->out_ep);
706 if (status < 0) {
707 ERROR(cdev, "Enable OUT endpoint FAILED!\n");
708 goto free_req_in;
709 }
710 hidg->out_ep->driver_data = hidg;
711
712 /*
713 * allocate a bunch of read buffers and queue them all at once.
714 */
715 for (i = 0; i < hidg->qlen && status == 0; i++) {
716 struct usb_request *req =
717 hidg_alloc_ep_req(hidg->out_ep,
718 hidg->report_length);
719 if (req) {
720 req->complete = hidg_set_report_complete;
721 req->context = hidg;
722 status = usb_ep_queue(hidg->out_ep, req,
723 GFP_ATOMIC);
724 if (status) {
725 ERROR(cdev, "%s queue req --> %d\n",
726 hidg->out_ep->name, status);
727 free_ep_req(hidg->out_ep, req);
728 }
729 } else {
730 status = -ENOMEM;
731 goto disable_out_ep;
732 }
733 }
734 }
735
736 if (hidg->in_ep != NULL) {
737 spin_lock_irqsave(&hidg->write_spinlock, flags);
738 hidg->req = req_in;
739 hidg->write_pending = 0;
740 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
741
742 wake_up(&hidg->write_queue);
743 }
744 return 0;
745disable_out_ep:
746 usb_ep_disable(hidg->out_ep);
747free_req_in:
748 if (req_in)
749 free_ep_req(hidg->in_ep, req_in);
750
751disable_ep_in:
752 if (hidg->in_ep)
753 usb_ep_disable(hidg->in_ep);
754
755fail:
756 return status;
757}
758
759static const struct file_operations f_hidg_fops = {
760 .owner = THIS_MODULE,
761 .open = f_hidg_open,
762 .release = f_hidg_release,
763 .write = f_hidg_write,
764 .read = f_hidg_read,
765 .poll = f_hidg_poll,
766 .llseek = noop_llseek,
767};
768
769static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
770{
771 struct usb_ep *ep;
772 struct f_hidg *hidg = func_to_hidg(f);
773 struct usb_string *us;
774 struct device *device;
775 int status;
776 dev_t dev;
777
778 /* maybe allocate device-global string IDs, and patch descriptors */
779 us = usb_gstrings_attach(c->cdev, ct_func_strings,
780 ARRAY_SIZE(ct_func_string_defs));
781 if (IS_ERR(us))
782 return PTR_ERR(us);
783 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
784
785 /* allocate instance-specific interface IDs, and patch descriptors */
786 status = usb_interface_id(c, f);
787 if (status < 0)
788 goto fail;
789 hidg_interface_desc.bInterfaceNumber = status;
790
791 /* allocate instance-specific endpoints */
792 status = -ENODEV;
793 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
794 if (!ep)
795 goto fail;
796 hidg->in_ep = ep;
797
798 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
799 if (!ep)
800 goto fail;
801 hidg->out_ep = ep;
802
803 /* set descriptor dynamic values */
804 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
805 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
806 hidg->protocol = HID_REPORT_PROTOCOL;
807 hidg->idle = 1;
808 hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
809 hidg_ss_in_comp_desc.wBytesPerInterval =
810 cpu_to_le16(hidg->report_length);
811 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
812 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
813 hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
814 hidg_ss_out_comp_desc.wBytesPerInterval =
815 cpu_to_le16(hidg->report_length);
816 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
817 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
818 /*
819 * We can use hidg_desc struct here but we should not relay
820 * that its content won't change after returning from this function.
821 */
822 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
823 hidg_desc.desc[0].wDescriptorLength =
824 cpu_to_le16(hidg->report_desc_length);
825
826 hidg_hs_in_ep_desc.bEndpointAddress =
827 hidg_fs_in_ep_desc.bEndpointAddress;
828 hidg_hs_out_ep_desc.bEndpointAddress =
829 hidg_fs_out_ep_desc.bEndpointAddress;
830
831 hidg_ss_in_ep_desc.bEndpointAddress =
832 hidg_fs_in_ep_desc.bEndpointAddress;
833 hidg_ss_out_ep_desc.bEndpointAddress =
834 hidg_fs_out_ep_desc.bEndpointAddress;
835
836 status = usb_assign_descriptors(f, hidg_fs_descriptors,
837 hidg_hs_descriptors, hidg_ss_descriptors,
838 hidg_ss_descriptors);
839 if (status)
840 goto fail;
841
842 spin_lock_init(&hidg->write_spinlock);
843 hidg->write_pending = 1;
844 hidg->req = NULL;
845 spin_lock_init(&hidg->read_spinlock);
846 init_waitqueue_head(&hidg->write_queue);
847 init_waitqueue_head(&hidg->read_queue);
848 INIT_LIST_HEAD(&hidg->completed_out_req);
849
850 /* create char device */
851 cdev_init(&hidg->cdev, &f_hidg_fops);
852 dev = MKDEV(major, hidg->minor);
853 status = cdev_add(&hidg->cdev, dev, 1);
854 if (status)
855 goto fail_free_descs;
856
857 device = device_create(hidg_class, NULL, dev, NULL,
858 "%s%d", "hidg", hidg->minor);
859 if (IS_ERR(device)) {
860 status = PTR_ERR(device);
861 goto del;
862 }
863
864 return 0;
865del:
866 cdev_del(&hidg->cdev);
867fail_free_descs:
868 usb_free_all_descriptors(f);
869fail:
870 ERROR(f->config->cdev, "hidg_bind FAILED\n");
871 if (hidg->req != NULL)
872 free_ep_req(hidg->in_ep, hidg->req);
873
874 return status;
875}
876
877static inline int hidg_get_minor(void)
878{
879 int ret;
880
881 ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
882 if (ret >= HIDG_MINORS) {
883 ida_simple_remove(&hidg_ida, ret);
884 ret = -ENODEV;
885 }
886
887 return ret;
888}
889
890static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
891{
892 return container_of(to_config_group(item), struct f_hid_opts,
893 func_inst.group);
894}
895
896static void hid_attr_release(struct config_item *item)
897{
898 struct f_hid_opts *opts = to_f_hid_opts(item);
899
900 usb_put_function_instance(&opts->func_inst);
901}
902
903static struct configfs_item_operations hidg_item_ops = {
904 .release = hid_attr_release,
905};
906
907#define F_HID_OPT(name, prec, limit) \
908static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
909{ \
910 struct f_hid_opts *opts = to_f_hid_opts(item); \
911 int result; \
912 \
913 mutex_lock(&opts->lock); \
914 result = sprintf(page, "%d\n", opts->name); \
915 mutex_unlock(&opts->lock); \
916 \
917 return result; \
918} \
919 \
920static ssize_t f_hid_opts_##name##_store(struct config_item *item, \
921 const char *page, size_t len) \
922{ \
923 struct f_hid_opts *opts = to_f_hid_opts(item); \
924 int ret; \
925 u##prec num; \
926 \
927 mutex_lock(&opts->lock); \
928 if (opts->refcnt) { \
929 ret = -EBUSY; \
930 goto end; \
931 } \
932 \
933 ret = kstrtou##prec(page, 0, &num); \
934 if (ret) \
935 goto end; \
936 \
937 if (num > limit) { \
938 ret = -EINVAL; \
939 goto end; \
940 } \
941 opts->name = num; \
942 ret = len; \
943 \
944end: \
945 mutex_unlock(&opts->lock); \
946 return ret; \
947} \
948 \
949CONFIGFS_ATTR(f_hid_opts_, name)
950
951F_HID_OPT(subclass, 8, 255);
952F_HID_OPT(protocol, 8, 255);
953F_HID_OPT(report_length, 16, 65535);
954
955static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
956{
957 struct f_hid_opts *opts = to_f_hid_opts(item);
958 int result;
959
960 mutex_lock(&opts->lock);
961 result = opts->report_desc_length;
962 memcpy(page, opts->report_desc, opts->report_desc_length);
963 mutex_unlock(&opts->lock);
964
965 return result;
966}
967
968static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
969 const char *page, size_t len)
970{
971 struct f_hid_opts *opts = to_f_hid_opts(item);
972 int ret = -EBUSY;
973 char *d;
974
975 mutex_lock(&opts->lock);
976
977 if (opts->refcnt)
978 goto end;
979 if (len > PAGE_SIZE) {
980 ret = -ENOSPC;
981 goto end;
982 }
983 d = kmemdup(page, len, GFP_KERNEL);
984 if (!d) {
985 ret = -ENOMEM;
986 goto end;
987 }
988 kfree(opts->report_desc);
989 opts->report_desc = d;
990 opts->report_desc_length = len;
991 opts->report_desc_alloc = true;
992 ret = len;
993end:
994 mutex_unlock(&opts->lock);
995 return ret;
996}
997
998CONFIGFS_ATTR(f_hid_opts_, report_desc);
999
1000static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1001{
1002 struct f_hid_opts *opts = to_f_hid_opts(item);
1003
1004 return sprintf(page, "%d:%d\n", major, opts->minor);
1005}
1006
1007CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1008
1009static struct configfs_attribute *hid_attrs[] = {
1010 &f_hid_opts_attr_subclass,
1011 &f_hid_opts_attr_protocol,
1012 &f_hid_opts_attr_report_length,
1013 &f_hid_opts_attr_report_desc,
1014 &f_hid_opts_attr_dev,
1015 NULL,
1016};
1017
1018static const struct config_item_type hid_func_type = {
1019 .ct_item_ops = &hidg_item_ops,
1020 .ct_attrs = hid_attrs,
1021 .ct_owner = THIS_MODULE,
1022};
1023
1024static inline void hidg_put_minor(int minor)
1025{
1026 ida_simple_remove(&hidg_ida, minor);
1027}
1028
1029static void hidg_free_inst(struct usb_function_instance *f)
1030{
1031 struct f_hid_opts *opts;
1032
1033 opts = container_of(f, struct f_hid_opts, func_inst);
1034
1035 mutex_lock(&hidg_ida_lock);
1036
1037 hidg_put_minor(opts->minor);
1038 if (ida_is_empty(&hidg_ida))
1039 ghid_cleanup();
1040
1041 mutex_unlock(&hidg_ida_lock);
1042
1043 if (opts->report_desc_alloc)
1044 kfree(opts->report_desc);
1045
1046 kfree(opts);
1047}
1048
1049static struct usb_function_instance *hidg_alloc_inst(void)
1050{
1051 struct f_hid_opts *opts;
1052 struct usb_function_instance *ret;
1053 int status = 0;
1054
1055 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1056 if (!opts)
1057 return ERR_PTR(-ENOMEM);
1058 mutex_init(&opts->lock);
1059 opts->func_inst.free_func_inst = hidg_free_inst;
1060 ret = &opts->func_inst;
1061
1062 mutex_lock(&hidg_ida_lock);
1063
1064 if (ida_is_empty(&hidg_ida)) {
1065 status = ghid_setup(NULL, HIDG_MINORS);
1066 if (status) {
1067 ret = ERR_PTR(status);
1068 kfree(opts);
1069 goto unlock;
1070 }
1071 }
1072
1073 opts->minor = hidg_get_minor();
1074 if (opts->minor < 0) {
1075 ret = ERR_PTR(opts->minor);
1076 kfree(opts);
1077 if (ida_is_empty(&hidg_ida))
1078 ghid_cleanup();
1079 goto unlock;
1080 }
1081 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1082
1083unlock:
1084 mutex_unlock(&hidg_ida_lock);
1085 return ret;
1086}
1087
1088static void hidg_free(struct usb_function *f)
1089{
1090 struct f_hidg *hidg;
1091 struct f_hid_opts *opts;
1092
1093 hidg = func_to_hidg(f);
1094 opts = container_of(f->fi, struct f_hid_opts, func_inst);
1095 kfree(hidg->report_desc);
1096 kfree(hidg);
1097 mutex_lock(&opts->lock);
1098 --opts->refcnt;
1099 mutex_unlock(&opts->lock);
1100}
1101
1102static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1103{
1104 struct f_hidg *hidg = func_to_hidg(f);
1105
1106 device_destroy(hidg_class, MKDEV(major, hidg->minor));
1107 cdev_del(&hidg->cdev);
1108
1109 usb_free_all_descriptors(f);
1110}
1111
1112static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1113{
1114 struct f_hidg *hidg;
1115 struct f_hid_opts *opts;
1116
1117 /* allocate and initialize one new instance */
1118 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1119 if (!hidg)
1120 return ERR_PTR(-ENOMEM);
1121
1122 opts = container_of(fi, struct f_hid_opts, func_inst);
1123
1124 mutex_lock(&opts->lock);
1125 ++opts->refcnt;
1126
1127 hidg->minor = opts->minor;
1128 hidg->bInterfaceSubClass = opts->subclass;
1129 hidg->bInterfaceProtocol = opts->protocol;
1130 hidg->report_length = opts->report_length;
1131 hidg->report_desc_length = opts->report_desc_length;
1132 if (opts->report_desc) {
1133 hidg->report_desc = kmemdup(opts->report_desc,
1134 opts->report_desc_length,
1135 GFP_KERNEL);
1136 if (!hidg->report_desc) {
1137 kfree(hidg);
1138 mutex_unlock(&opts->lock);
1139 return ERR_PTR(-ENOMEM);
1140 }
1141 }
1142
1143 mutex_unlock(&opts->lock);
1144
1145 hidg->func.name = "hid";
1146 hidg->func.bind = hidg_bind;
1147 hidg->func.unbind = hidg_unbind;
1148 hidg->func.set_alt = hidg_set_alt;
1149 hidg->func.disable = hidg_disable;
1150 hidg->func.setup = hidg_setup;
1151 hidg->func.free_func = hidg_free;
1152
1153 /* this could be made configurable at some point */
1154 hidg->qlen = 4;
1155
1156 return &hidg->func;
1157}
1158
1159DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1160MODULE_LICENSE("GPL");
1161MODULE_AUTHOR("Fabien Chouteau");
1162
1163int ghid_setup(struct usb_gadget *g, int count)
1164{
1165 int status;
1166 dev_t dev;
1167
1168 hidg_class = class_create(THIS_MODULE, "hidg");
1169 if (IS_ERR(hidg_class)) {
1170 status = PTR_ERR(hidg_class);
1171 hidg_class = NULL;
1172 return status;
1173 }
1174
1175 status = alloc_chrdev_region(&dev, 0, count, "hidg");
1176 if (status) {
1177 class_destroy(hidg_class);
1178 hidg_class = NULL;
1179 return status;
1180 }
1181
1182 major = MAJOR(dev);
1183 minors = count;
1184
1185 return 0;
1186}
1187
1188void ghid_cleanup(void)
1189{
1190 if (major) {
1191 unregister_chrdev_region(MKDEV(major, 0), minors);
1192 major = minors = 0;
1193 }
1194
1195 class_destroy(hidg_class);
1196 hidg_class = NULL;
1197}