Merge tag 'acpi-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[muen/linux.git] / drivers / usb / gadget / function / f_hid.c
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
25 static int major, minors;
26 static struct class *hidg_class;
27 static DEFINE_IDA(hidg_ida);
28 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
29
30 /*-------------------------------------------------------------------------*/
31 /*                            HID gadget struct                            */
32
33 struct f_hidg_req_list {
34         struct usb_request      *req;
35         unsigned int            pos;
36         struct list_head        list;
37 };
38
39 struct 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
68 static 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
76 static 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
88 static 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
100 static 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
112 static 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
121 static 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
133 static 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
142 static 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
154 static 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
166 static 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
178 static 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
188 static 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
200 static 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
212 static 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
225 static struct usb_string ct_func_string_defs[] = {
226         [CT_FUNC_HID_IDX].s     = "HID Interface",
227         {},                     /* end of list */
228 };
229
230 static struct usb_gadget_strings ct_func_string_table = {
231         .language       = 0x0409,       /* en-US */
232         .strings        = ct_func_string_defs,
233 };
234
235 static struct usb_gadget_strings *ct_func_strings[] = {
236         &ct_func_string_table,
237         NULL,
238 };
239
240 /*-------------------------------------------------------------------------*/
241 /*                              Char Device                                */
242
243 static 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         if (!access_ok(buffer, count))
256                 return -EFAULT;
257
258         spin_lock_irqsave(&hidg->read_spinlock, flags);
259
260 #define READ_COND (!list_empty(&hidg->completed_out_req))
261
262         /* wait for at least one buffer to complete */
263         while (!READ_COND) {
264                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
265                 if (file->f_flags & O_NONBLOCK)
266                         return -EAGAIN;
267
268                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
269                         return -ERESTARTSYS;
270
271                 spin_lock_irqsave(&hidg->read_spinlock, flags);
272         }
273
274         /* pick the first one */
275         list = list_first_entry(&hidg->completed_out_req,
276                                 struct f_hidg_req_list, list);
277
278         /*
279          * Remove this from list to protect it from beign free()
280          * while host disables our function
281          */
282         list_del(&list->list);
283
284         req = list->req;
285         count = min_t(unsigned int, count, req->actual - list->pos);
286         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
287
288         /* copy to user outside spinlock */
289         count -= copy_to_user(buffer, req->buf + list->pos, count);
290         list->pos += count;
291
292         /*
293          * if this request is completely handled and transfered to
294          * userspace, remove its entry from the list and requeue it
295          * again. Otherwise, we will revisit it again upon the next
296          * call, taking into account its current read position.
297          */
298         if (list->pos == req->actual) {
299                 kfree(list);
300
301                 req->length = hidg->report_length;
302                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
303                 if (ret < 0) {
304                         free_ep_req(hidg->out_ep, req);
305                         return ret;
306                 }
307         } else {
308                 spin_lock_irqsave(&hidg->read_spinlock, flags);
309                 list_add(&list->list, &hidg->completed_out_req);
310                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
311
312                 wake_up(&hidg->read_queue);
313         }
314
315         return count;
316 }
317
318 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
319 {
320         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
321         unsigned long flags;
322
323         if (req->status != 0) {
324                 ERROR(hidg->func.config->cdev,
325                         "End Point Request ERROR: %d\n", req->status);
326         }
327
328         spin_lock_irqsave(&hidg->write_spinlock, flags);
329         hidg->write_pending = 0;
330         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
331         wake_up(&hidg->write_queue);
332 }
333
334 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
335                             size_t count, loff_t *offp)
336 {
337         struct f_hidg *hidg  = file->private_data;
338         struct usb_request *req;
339         unsigned long flags;
340         ssize_t status = -ENOMEM;
341
342         if (!access_ok(buffer, count))
343                 return -EFAULT;
344
345         spin_lock_irqsave(&hidg->write_spinlock, flags);
346
347 #define WRITE_COND (!hidg->write_pending)
348 try_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         status = copy_from_user(req->buf, buffer, count);
368
369         if (status != 0) {
370                 ERROR(hidg->func.config->cdev,
371                         "copy_from_user error\n");
372                 status = -EINVAL;
373                 goto release_write_pending;
374         }
375
376         spin_lock_irqsave(&hidg->write_spinlock, flags);
377
378         /* when our function has been disabled by host */
379         if (!hidg->req) {
380                 free_ep_req(hidg->in_ep, req);
381                 /*
382                  * TODO
383                  * Should we fail with error here?
384                  */
385                 goto try_again;
386         }
387
388         req->status   = 0;
389         req->zero     = 0;
390         req->length   = count;
391         req->complete = f_hidg_req_complete;
392         req->context  = hidg;
393
394         status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
395         if (status < 0) {
396                 ERROR(hidg->func.config->cdev,
397                         "usb_ep_queue error on int endpoint %zd\n", status);
398                 goto release_write_pending_unlocked;
399         } else {
400                 status = count;
401         }
402         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
403
404         return status;
405 release_write_pending:
406         spin_lock_irqsave(&hidg->write_spinlock, flags);
407 release_write_pending_unlocked:
408         hidg->write_pending = 0;
409         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
410
411         wake_up(&hidg->write_queue);
412
413         return status;
414 }
415
416 static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
417 {
418         struct f_hidg   *hidg  = file->private_data;
419         __poll_t        ret = 0;
420
421         poll_wait(file, &hidg->read_queue, wait);
422         poll_wait(file, &hidg->write_queue, wait);
423
424         if (WRITE_COND)
425                 ret |= EPOLLOUT | EPOLLWRNORM;
426
427         if (READ_COND)
428                 ret |= EPOLLIN | EPOLLRDNORM;
429
430         return ret;
431 }
432
433 #undef WRITE_COND
434 #undef READ_COND
435
436 static int f_hidg_release(struct inode *inode, struct file *fd)
437 {
438         fd->private_data = NULL;
439         return 0;
440 }
441
442 static int f_hidg_open(struct inode *inode, struct file *fd)
443 {
444         struct f_hidg *hidg =
445                 container_of(inode->i_cdev, struct f_hidg, cdev);
446
447         fd->private_data = hidg;
448
449         return 0;
450 }
451
452 /*-------------------------------------------------------------------------*/
453 /*                                usb_function                             */
454
455 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
456                                                     unsigned length)
457 {
458         return alloc_ep_req(ep, length);
459 }
460
461 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
462 {
463         struct f_hidg *hidg = (struct f_hidg *) req->context;
464         struct usb_composite_dev *cdev = hidg->func.config->cdev;
465         struct f_hidg_req_list *req_list;
466         unsigned long flags;
467
468         switch (req->status) {
469         case 0:
470                 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
471                 if (!req_list) {
472                         ERROR(cdev, "Unable to allocate mem for req_list\n");
473                         goto free_req;
474                 }
475
476                 req_list->req = req;
477
478                 spin_lock_irqsave(&hidg->read_spinlock, flags);
479                 list_add_tail(&req_list->list, &hidg->completed_out_req);
480                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
481
482                 wake_up(&hidg->read_queue);
483                 break;
484         default:
485                 ERROR(cdev, "Set report failed %d\n", req->status);
486                 /* FALLTHROUGH */
487         case -ECONNABORTED:             /* hardware forced ep reset */
488         case -ECONNRESET:               /* request dequeued */
489         case -ESHUTDOWN:                /* disconnect from host */
490 free_req:
491                 free_ep_req(ep, req);
492                 return;
493         }
494 }
495
496 static int hidg_setup(struct usb_function *f,
497                 const struct usb_ctrlrequest *ctrl)
498 {
499         struct f_hidg                   *hidg = func_to_hidg(f);
500         struct usb_composite_dev        *cdev = f->config->cdev;
501         struct usb_request              *req  = cdev->req;
502         int status = 0;
503         __u16 value, length;
504
505         value   = __le16_to_cpu(ctrl->wValue);
506         length  = __le16_to_cpu(ctrl->wLength);
507
508         VDBG(cdev,
509              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
510              __func__, ctrl->bRequestType, ctrl->bRequest, value);
511
512         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
513         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
514                   | HID_REQ_GET_REPORT):
515                 VDBG(cdev, "get_report\n");
516
517                 /* send an empty report */
518                 length = min_t(unsigned, length, hidg->report_length);
519                 memset(req->buf, 0x0, length);
520
521                 goto respond;
522                 break;
523
524         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
525                   | HID_REQ_GET_PROTOCOL):
526                 VDBG(cdev, "get_protocol\n");
527                 length = min_t(unsigned int, length, 1);
528                 ((u8 *) req->buf)[0] = hidg->protocol;
529                 goto respond;
530                 break;
531
532         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
533                   | HID_REQ_SET_REPORT):
534                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
535                 goto stall;
536                 break;
537
538         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
539                   | HID_REQ_SET_PROTOCOL):
540                 VDBG(cdev, "set_protocol\n");
541                 if (value > HID_REPORT_PROTOCOL)
542                         goto stall;
543                 length = 0;
544                 /*
545                  * We assume that programs implementing the Boot protocol
546                  * are also compatible with the Report Protocol
547                  */
548                 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
549                         hidg->protocol = value;
550                         goto respond;
551                 }
552                 goto stall;
553                 break;
554
555         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
556                   | USB_REQ_GET_DESCRIPTOR):
557                 switch (value >> 8) {
558                 case HID_DT_HID:
559                 {
560                         struct hid_descriptor hidg_desc_copy = hidg_desc;
561
562                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
563                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
564                         hidg_desc_copy.desc[0].wDescriptorLength =
565                                 cpu_to_le16(hidg->report_desc_length);
566
567                         length = min_t(unsigned short, length,
568                                                    hidg_desc_copy.bLength);
569                         memcpy(req->buf, &hidg_desc_copy, length);
570                         goto respond;
571                         break;
572                 }
573                 case HID_DT_REPORT:
574                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
575                         length = min_t(unsigned short, length,
576                                                    hidg->report_desc_length);
577                         memcpy(req->buf, hidg->report_desc, length);
578                         goto respond;
579                         break;
580
581                 default:
582                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
583                                  value >> 8);
584                         goto stall;
585                         break;
586                 }
587                 break;
588
589         default:
590                 VDBG(cdev, "Unknown request 0x%x\n",
591                          ctrl->bRequest);
592                 goto stall;
593                 break;
594         }
595
596 stall:
597         return -EOPNOTSUPP;
598
599 respond:
600         req->zero = 0;
601         req->length = length;
602         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
603         if (status < 0)
604                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
605         return status;
606 }
607
608 static void hidg_disable(struct usb_function *f)
609 {
610         struct f_hidg *hidg = func_to_hidg(f);
611         struct f_hidg_req_list *list, *next;
612         unsigned long flags;
613
614         usb_ep_disable(hidg->in_ep);
615         usb_ep_disable(hidg->out_ep);
616
617         spin_lock_irqsave(&hidg->read_spinlock, flags);
618         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
619                 free_ep_req(hidg->out_ep, list->req);
620                 list_del(&list->list);
621                 kfree(list);
622         }
623         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
624
625         spin_lock_irqsave(&hidg->write_spinlock, flags);
626         if (!hidg->write_pending) {
627                 free_ep_req(hidg->in_ep, hidg->req);
628                 hidg->write_pending = 1;
629         }
630
631         hidg->req = NULL;
632         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
633 }
634
635 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
636 {
637         struct usb_composite_dev                *cdev = f->config->cdev;
638         struct f_hidg                           *hidg = func_to_hidg(f);
639         struct usb_request                      *req_in = NULL;
640         unsigned long                           flags;
641         int i, status = 0;
642
643         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
644
645         if (hidg->in_ep != NULL) {
646                 /* restart endpoint */
647                 usb_ep_disable(hidg->in_ep);
648
649                 status = config_ep_by_speed(f->config->cdev->gadget, f,
650                                             hidg->in_ep);
651                 if (status) {
652                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
653                         goto fail;
654                 }
655                 status = usb_ep_enable(hidg->in_ep);
656                 if (status < 0) {
657                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
658                         goto fail;
659                 }
660                 hidg->in_ep->driver_data = hidg;
661
662                 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
663                 if (!req_in) {
664                         status = -ENOMEM;
665                         goto disable_ep_in;
666                 }
667         }
668
669
670         if (hidg->out_ep != NULL) {
671                 /* restart endpoint */
672                 usb_ep_disable(hidg->out_ep);
673
674                 status = config_ep_by_speed(f->config->cdev->gadget, f,
675                                             hidg->out_ep);
676                 if (status) {
677                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
678                         goto free_req_in;
679                 }
680                 status = usb_ep_enable(hidg->out_ep);
681                 if (status < 0) {
682                         ERROR(cdev, "Enable OUT endpoint FAILED!\n");
683                         goto free_req_in;
684                 }
685                 hidg->out_ep->driver_data = hidg;
686
687                 /*
688                  * allocate a bunch of read buffers and queue them all at once.
689                  */
690                 for (i = 0; i < hidg->qlen && status == 0; i++) {
691                         struct usb_request *req =
692                                         hidg_alloc_ep_req(hidg->out_ep,
693                                                           hidg->report_length);
694                         if (req) {
695                                 req->complete = hidg_set_report_complete;
696                                 req->context  = hidg;
697                                 status = usb_ep_queue(hidg->out_ep, req,
698                                                       GFP_ATOMIC);
699                                 if (status) {
700                                         ERROR(cdev, "%s queue req --> %d\n",
701                                                 hidg->out_ep->name, status);
702                                         free_ep_req(hidg->out_ep, req);
703                                 }
704                         } else {
705                                 status = -ENOMEM;
706                                 goto disable_out_ep;
707                         }
708                 }
709         }
710
711         if (hidg->in_ep != NULL) {
712                 spin_lock_irqsave(&hidg->write_spinlock, flags);
713                 hidg->req = req_in;
714                 hidg->write_pending = 0;
715                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
716
717                 wake_up(&hidg->write_queue);
718         }
719         return 0;
720 disable_out_ep:
721         usb_ep_disable(hidg->out_ep);
722 free_req_in:
723         if (req_in)
724                 free_ep_req(hidg->in_ep, req_in);
725
726 disable_ep_in:
727         if (hidg->in_ep)
728                 usb_ep_disable(hidg->in_ep);
729
730 fail:
731         return status;
732 }
733
734 static const struct file_operations f_hidg_fops = {
735         .owner          = THIS_MODULE,
736         .open           = f_hidg_open,
737         .release        = f_hidg_release,
738         .write          = f_hidg_write,
739         .read           = f_hidg_read,
740         .poll           = f_hidg_poll,
741         .llseek         = noop_llseek,
742 };
743
744 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
745 {
746         struct usb_ep           *ep;
747         struct f_hidg           *hidg = func_to_hidg(f);
748         struct usb_string       *us;
749         struct device           *device;
750         int                     status;
751         dev_t                   dev;
752
753         /* maybe allocate device-global string IDs, and patch descriptors */
754         us = usb_gstrings_attach(c->cdev, ct_func_strings,
755                                  ARRAY_SIZE(ct_func_string_defs));
756         if (IS_ERR(us))
757                 return PTR_ERR(us);
758         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
759
760         /* allocate instance-specific interface IDs, and patch descriptors */
761         status = usb_interface_id(c, f);
762         if (status < 0)
763                 goto fail;
764         hidg_interface_desc.bInterfaceNumber = status;
765
766         /* allocate instance-specific endpoints */
767         status = -ENODEV;
768         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
769         if (!ep)
770                 goto fail;
771         hidg->in_ep = ep;
772
773         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
774         if (!ep)
775                 goto fail;
776         hidg->out_ep = ep;
777
778         /* set descriptor dynamic values */
779         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
780         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
781         hidg->protocol = HID_REPORT_PROTOCOL;
782         hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
783         hidg_ss_in_comp_desc.wBytesPerInterval =
784                                 cpu_to_le16(hidg->report_length);
785         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
786         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
787         hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
788         hidg_ss_out_comp_desc.wBytesPerInterval =
789                                 cpu_to_le16(hidg->report_length);
790         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
791         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
792         /*
793          * We can use hidg_desc struct here but we should not relay
794          * that its content won't change after returning from this function.
795          */
796         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
797         hidg_desc.desc[0].wDescriptorLength =
798                 cpu_to_le16(hidg->report_desc_length);
799
800         hidg_hs_in_ep_desc.bEndpointAddress =
801                 hidg_fs_in_ep_desc.bEndpointAddress;
802         hidg_hs_out_ep_desc.bEndpointAddress =
803                 hidg_fs_out_ep_desc.bEndpointAddress;
804
805         hidg_ss_in_ep_desc.bEndpointAddress =
806                 hidg_fs_in_ep_desc.bEndpointAddress;
807         hidg_ss_out_ep_desc.bEndpointAddress =
808                 hidg_fs_out_ep_desc.bEndpointAddress;
809
810         status = usb_assign_descriptors(f, hidg_fs_descriptors,
811                         hidg_hs_descriptors, hidg_ss_descriptors, NULL);
812         if (status)
813                 goto fail;
814
815         spin_lock_init(&hidg->write_spinlock);
816         hidg->write_pending = 1;
817         hidg->req = NULL;
818         spin_lock_init(&hidg->read_spinlock);
819         init_waitqueue_head(&hidg->write_queue);
820         init_waitqueue_head(&hidg->read_queue);
821         INIT_LIST_HEAD(&hidg->completed_out_req);
822
823         /* create char device */
824         cdev_init(&hidg->cdev, &f_hidg_fops);
825         dev = MKDEV(major, hidg->minor);
826         status = cdev_add(&hidg->cdev, dev, 1);
827         if (status)
828                 goto fail_free_descs;
829
830         device = device_create(hidg_class, NULL, dev, NULL,
831                                "%s%d", "hidg", hidg->minor);
832         if (IS_ERR(device)) {
833                 status = PTR_ERR(device);
834                 goto del;
835         }
836
837         return 0;
838 del:
839         cdev_del(&hidg->cdev);
840 fail_free_descs:
841         usb_free_all_descriptors(f);
842 fail:
843         ERROR(f->config->cdev, "hidg_bind FAILED\n");
844         if (hidg->req != NULL)
845                 free_ep_req(hidg->in_ep, hidg->req);
846
847         return status;
848 }
849
850 static inline int hidg_get_minor(void)
851 {
852         int ret;
853
854         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
855         if (ret >= HIDG_MINORS) {
856                 ida_simple_remove(&hidg_ida, ret);
857                 ret = -ENODEV;
858         }
859
860         return ret;
861 }
862
863 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
864 {
865         return container_of(to_config_group(item), struct f_hid_opts,
866                             func_inst.group);
867 }
868
869 static void hid_attr_release(struct config_item *item)
870 {
871         struct f_hid_opts *opts = to_f_hid_opts(item);
872
873         usb_put_function_instance(&opts->func_inst);
874 }
875
876 static struct configfs_item_operations hidg_item_ops = {
877         .release        = hid_attr_release,
878 };
879
880 #define F_HID_OPT(name, prec, limit)                                    \
881 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
882 {                                                                       \
883         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
884         int result;                                                     \
885                                                                         \
886         mutex_lock(&opts->lock);                                        \
887         result = sprintf(page, "%d\n", opts->name);                     \
888         mutex_unlock(&opts->lock);                                      \
889                                                                         \
890         return result;                                                  \
891 }                                                                       \
892                                                                         \
893 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
894                                          const char *page, size_t len)  \
895 {                                                                       \
896         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
897         int ret;                                                        \
898         u##prec num;                                                    \
899                                                                         \
900         mutex_lock(&opts->lock);                                        \
901         if (opts->refcnt) {                                             \
902                 ret = -EBUSY;                                           \
903                 goto end;                                               \
904         }                                                               \
905                                                                         \
906         ret = kstrtou##prec(page, 0, &num);                             \
907         if (ret)                                                        \
908                 goto end;                                               \
909                                                                         \
910         if (num > limit) {                                              \
911                 ret = -EINVAL;                                          \
912                 goto end;                                               \
913         }                                                               \
914         opts->name = num;                                               \
915         ret = len;                                                      \
916                                                                         \
917 end:                                                                    \
918         mutex_unlock(&opts->lock);                                      \
919         return ret;                                                     \
920 }                                                                       \
921                                                                         \
922 CONFIGFS_ATTR(f_hid_opts_, name)
923
924 F_HID_OPT(subclass, 8, 255);
925 F_HID_OPT(protocol, 8, 255);
926 F_HID_OPT(report_length, 16, 65535);
927
928 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
929 {
930         struct f_hid_opts *opts = to_f_hid_opts(item);
931         int result;
932
933         mutex_lock(&opts->lock);
934         result = opts->report_desc_length;
935         memcpy(page, opts->report_desc, opts->report_desc_length);
936         mutex_unlock(&opts->lock);
937
938         return result;
939 }
940
941 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
942                                             const char *page, size_t len)
943 {
944         struct f_hid_opts *opts = to_f_hid_opts(item);
945         int ret = -EBUSY;
946         char *d;
947
948         mutex_lock(&opts->lock);
949
950         if (opts->refcnt)
951                 goto end;
952         if (len > PAGE_SIZE) {
953                 ret = -ENOSPC;
954                 goto end;
955         }
956         d = kmemdup(page, len, GFP_KERNEL);
957         if (!d) {
958                 ret = -ENOMEM;
959                 goto end;
960         }
961         kfree(opts->report_desc);
962         opts->report_desc = d;
963         opts->report_desc_length = len;
964         opts->report_desc_alloc = true;
965         ret = len;
966 end:
967         mutex_unlock(&opts->lock);
968         return ret;
969 }
970
971 CONFIGFS_ATTR(f_hid_opts_, report_desc);
972
973 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
974 {
975         struct f_hid_opts *opts = to_f_hid_opts(item);
976
977         return sprintf(page, "%d:%d\n", major, opts->minor);
978 }
979
980 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
981
982 static struct configfs_attribute *hid_attrs[] = {
983         &f_hid_opts_attr_subclass,
984         &f_hid_opts_attr_protocol,
985         &f_hid_opts_attr_report_length,
986         &f_hid_opts_attr_report_desc,
987         &f_hid_opts_attr_dev,
988         NULL,
989 };
990
991 static const struct config_item_type hid_func_type = {
992         .ct_item_ops    = &hidg_item_ops,
993         .ct_attrs       = hid_attrs,
994         .ct_owner       = THIS_MODULE,
995 };
996
997 static inline void hidg_put_minor(int minor)
998 {
999         ida_simple_remove(&hidg_ida, minor);
1000 }
1001
1002 static void hidg_free_inst(struct usb_function_instance *f)
1003 {
1004         struct f_hid_opts *opts;
1005
1006         opts = container_of(f, struct f_hid_opts, func_inst);
1007
1008         mutex_lock(&hidg_ida_lock);
1009
1010         hidg_put_minor(opts->minor);
1011         if (ida_is_empty(&hidg_ida))
1012                 ghid_cleanup();
1013
1014         mutex_unlock(&hidg_ida_lock);
1015
1016         if (opts->report_desc_alloc)
1017                 kfree(opts->report_desc);
1018
1019         kfree(opts);
1020 }
1021
1022 static struct usb_function_instance *hidg_alloc_inst(void)
1023 {
1024         struct f_hid_opts *opts;
1025         struct usb_function_instance *ret;
1026         int status = 0;
1027
1028         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1029         if (!opts)
1030                 return ERR_PTR(-ENOMEM);
1031         mutex_init(&opts->lock);
1032         opts->func_inst.free_func_inst = hidg_free_inst;
1033         ret = &opts->func_inst;
1034
1035         mutex_lock(&hidg_ida_lock);
1036
1037         if (ida_is_empty(&hidg_ida)) {
1038                 status = ghid_setup(NULL, HIDG_MINORS);
1039                 if (status)  {
1040                         ret = ERR_PTR(status);
1041                         kfree(opts);
1042                         goto unlock;
1043                 }
1044         }
1045
1046         opts->minor = hidg_get_minor();
1047         if (opts->minor < 0) {
1048                 ret = ERR_PTR(opts->minor);
1049                 kfree(opts);
1050                 if (ida_is_empty(&hidg_ida))
1051                         ghid_cleanup();
1052                 goto unlock;
1053         }
1054         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1055
1056 unlock:
1057         mutex_unlock(&hidg_ida_lock);
1058         return ret;
1059 }
1060
1061 static void hidg_free(struct usb_function *f)
1062 {
1063         struct f_hidg *hidg;
1064         struct f_hid_opts *opts;
1065
1066         hidg = func_to_hidg(f);
1067         opts = container_of(f->fi, struct f_hid_opts, func_inst);
1068         kfree(hidg->report_desc);
1069         kfree(hidg);
1070         mutex_lock(&opts->lock);
1071         --opts->refcnt;
1072         mutex_unlock(&opts->lock);
1073 }
1074
1075 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1076 {
1077         struct f_hidg *hidg = func_to_hidg(f);
1078
1079         device_destroy(hidg_class, MKDEV(major, hidg->minor));
1080         cdev_del(&hidg->cdev);
1081
1082         usb_free_all_descriptors(f);
1083 }
1084
1085 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1086 {
1087         struct f_hidg *hidg;
1088         struct f_hid_opts *opts;
1089
1090         /* allocate and initialize one new instance */
1091         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1092         if (!hidg)
1093                 return ERR_PTR(-ENOMEM);
1094
1095         opts = container_of(fi, struct f_hid_opts, func_inst);
1096
1097         mutex_lock(&opts->lock);
1098         ++opts->refcnt;
1099
1100         hidg->minor = opts->minor;
1101         hidg->bInterfaceSubClass = opts->subclass;
1102         hidg->bInterfaceProtocol = opts->protocol;
1103         hidg->report_length = opts->report_length;
1104         hidg->report_desc_length = opts->report_desc_length;
1105         if (opts->report_desc) {
1106                 hidg->report_desc = kmemdup(opts->report_desc,
1107                                             opts->report_desc_length,
1108                                             GFP_KERNEL);
1109                 if (!hidg->report_desc) {
1110                         kfree(hidg);
1111                         mutex_unlock(&opts->lock);
1112                         return ERR_PTR(-ENOMEM);
1113                 }
1114         }
1115
1116         mutex_unlock(&opts->lock);
1117
1118         hidg->func.name    = "hid";
1119         hidg->func.bind    = hidg_bind;
1120         hidg->func.unbind  = hidg_unbind;
1121         hidg->func.set_alt = hidg_set_alt;
1122         hidg->func.disable = hidg_disable;
1123         hidg->func.setup   = hidg_setup;
1124         hidg->func.free_func = hidg_free;
1125
1126         /* this could me made configurable at some point */
1127         hidg->qlen         = 4;
1128
1129         return &hidg->func;
1130 }
1131
1132 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1133 MODULE_LICENSE("GPL");
1134 MODULE_AUTHOR("Fabien Chouteau");
1135
1136 int ghid_setup(struct usb_gadget *g, int count)
1137 {
1138         int status;
1139         dev_t dev;
1140
1141         hidg_class = class_create(THIS_MODULE, "hidg");
1142         if (IS_ERR(hidg_class)) {
1143                 status = PTR_ERR(hidg_class);
1144                 hidg_class = NULL;
1145                 return status;
1146         }
1147
1148         status = alloc_chrdev_region(&dev, 0, count, "hidg");
1149         if (status) {
1150                 class_destroy(hidg_class);
1151                 hidg_class = NULL;
1152                 return status;
1153         }
1154
1155         major = MAJOR(dev);
1156         minors = count;
1157
1158         return 0;
1159 }
1160
1161 void ghid_cleanup(void)
1162 {
1163         if (major) {
1164                 unregister_chrdev_region(MKDEV(major, 0), minors);
1165                 major = minors = 0;
1166         }
1167
1168         class_destroy(hidg_class);
1169         hidg_class = NULL;
1170 }