USB: gadget: add HID gadget driver
[linux-3.10.git] / drivers / usb / gadget / f_hid.c
1 /*
2  * f_hid.c -- USB HID function driver
3  *
4  * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20
21 #include <linux/kernel.h>
22 #include <linux/utsname.h>
23 #include <linux/module.h>
24 #include <linux/hid.h>
25 #include <linux/cdev.h>
26 #include <linux/mutex.h>
27 #include <linux/poll.h>
28 #include <linux/smp_lock.h>
29 #include <linux/uaccess.h>
30 #include <linux/wait.h>
31 #include <linux/usb/g_hid.h>
32
33 static int major, minors;
34 static struct class *hidg_class;
35
36 /*-------------------------------------------------------------------------*/
37 /*                            HID gadget struct                            */
38
39 struct f_hidg {
40         /* configuration */
41         unsigned char                   bInterfaceSubClass;
42         unsigned char                   bInterfaceProtocol;
43         unsigned short                  report_desc_length;
44         char                            *report_desc;
45         unsigned short                  report_length;
46
47         /* recv report */
48         char                            *set_report_buff;
49         unsigned short                  set_report_length;
50         spinlock_t                      spinlock;
51         wait_queue_head_t               read_queue;
52
53         /* send report */
54         struct mutex                    lock;
55         bool                            write_pending;
56         wait_queue_head_t               write_queue;
57         struct usb_request              *req;
58
59         int                             minor;
60         struct cdev                     cdev;
61         struct usb_function             func;
62         struct usb_ep                   *in_ep;
63         struct usb_endpoint_descriptor  *fs_in_ep_desc;
64         struct usb_endpoint_descriptor  *hs_in_ep_desc;
65 };
66
67 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
68 {
69         return container_of(f, struct f_hidg, func);
70 }
71
72 /*-------------------------------------------------------------------------*/
73 /*                           Static descriptors                            */
74
75 static struct usb_interface_descriptor hidg_interface_desc = {
76         .bLength                = sizeof hidg_interface_desc,
77         .bDescriptorType        = USB_DT_INTERFACE,
78         /* .bInterfaceNumber    = DYNAMIC */
79         .bAlternateSetting      = 0,
80         .bNumEndpoints          = 1,
81         .bInterfaceClass        = USB_CLASS_HID,
82         /* .bInterfaceSubClass  = DYNAMIC */
83         /* .bInterfaceProtocol  = DYNAMIC */
84         /* .iInterface          = DYNAMIC */
85 };
86
87 static struct hid_descriptor hidg_desc = {
88         .bLength                        = sizeof hidg_desc,
89         .bDescriptorType                = HID_DT_HID,
90         .bcdHID                         = 0x0101,
91         .bCountryCode                   = 0x00,
92         .bNumDescriptors                = 0x1,
93         /*.desc[0].bDescriptorType      = DYNAMIC */
94         /*.desc[0].wDescriptorLenght    = DYNAMIC */
95 };
96
97 /* High-Speed Support */
98
99 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
100         .bLength                = USB_DT_ENDPOINT_SIZE,
101         .bDescriptorType        = USB_DT_ENDPOINT,
102         .bEndpointAddress       = USB_DIR_IN,
103         .bmAttributes           = USB_ENDPOINT_XFER_INT,
104         /*.wMaxPacketSize       = DYNAMIC */
105         .bInterval              = 4, /* FIXME: Add this field in the
106                                       * HID gadget configuration?
107                                       * (struct hidg_func_descriptor)
108                                       */
109 };
110
111 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
112         (struct usb_descriptor_header *)&hidg_interface_desc,
113         (struct usb_descriptor_header *)&hidg_desc,
114         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
115         NULL,
116 };
117
118 /* Full-Speed Support */
119
120 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
121         .bLength                = USB_DT_ENDPOINT_SIZE,
122         .bDescriptorType        = USB_DT_ENDPOINT,
123         .bEndpointAddress       = USB_DIR_IN,
124         .bmAttributes           = USB_ENDPOINT_XFER_INT,
125         /*.wMaxPacketSize       = DYNAMIC */
126         .bInterval              = 10, /* FIXME: Add this field in the
127                                        * HID gadget configuration?
128                                        * (struct hidg_func_descriptor)
129                                        */
130 };
131
132 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
133         (struct usb_descriptor_header *)&hidg_interface_desc,
134         (struct usb_descriptor_header *)&hidg_desc,
135         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
136         NULL,
137 };
138
139 /*-------------------------------------------------------------------------*/
140 /*                              Char Device                                */
141
142 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
143                         size_t count, loff_t *ptr)
144 {
145         struct f_hidg   *hidg     = (struct f_hidg *)file->private_data;
146         char            *tmp_buff = NULL;
147         unsigned long   flags;
148
149         if (!count)
150                 return 0;
151
152         if (!access_ok(VERIFY_WRITE, buffer, count))
153                 return -EFAULT;
154
155         spin_lock_irqsave(&hidg->spinlock, flags);
156
157 #define READ_COND (hidg->set_report_buff != NULL)
158
159         while (!READ_COND) {
160                 spin_unlock_irqrestore(&hidg->spinlock, flags);
161                 if (file->f_flags & O_NONBLOCK)
162                         return -EAGAIN;
163
164                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
165                         return -ERESTARTSYS;
166
167                 spin_lock_irqsave(&hidg->spinlock, flags);
168         }
169
170
171         count = min_t(unsigned, count, hidg->set_report_length);
172         tmp_buff = hidg->set_report_buff;
173         hidg->set_report_buff = NULL;
174
175         spin_unlock_irqrestore(&hidg->spinlock, flags);
176
177         if (tmp_buff != NULL) {
178                 /* copy to user outside spinlock */
179                 count -= copy_to_user(buffer, tmp_buff, count);
180                 kfree(tmp_buff);
181         } else
182                 count = -ENOMEM;
183
184         return count;
185 }
186
187 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
188 {
189         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
190
191         if (req->status != 0) {
192                 ERROR(hidg->func.config->cdev,
193                         "End Point Request ERROR: %d\n", req->status);
194         }
195
196         hidg->write_pending = 0;
197         wake_up(&hidg->write_queue);
198 }
199
200 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
201                             size_t count, loff_t *offp)
202 {
203         struct f_hidg *hidg  = (struct f_hidg *)file->private_data;
204         ssize_t status = -ENOMEM;
205
206         if (!access_ok(VERIFY_READ, buffer, count))
207                 return -EFAULT;
208
209         mutex_lock(&hidg->lock);
210
211 #define WRITE_COND (!hidg->write_pending)
212
213         /* write queue */
214         while (!WRITE_COND) {
215                 mutex_unlock(&hidg->lock);
216                 if (file->f_flags & O_NONBLOCK)
217                         return -EAGAIN;
218
219                 if (wait_event_interruptible_exclusive(
220                                 hidg->write_queue, WRITE_COND))
221                         return -ERESTARTSYS;
222
223                 mutex_lock(&hidg->lock);
224         }
225
226         count  = min_t(unsigned, count, hidg->report_length);
227         status = copy_from_user(hidg->req->buf, buffer, count);
228
229         if (status != 0) {
230                 ERROR(hidg->func.config->cdev,
231                         "copy_from_user error\n");
232                 mutex_unlock(&hidg->lock);
233                 return -EINVAL;
234         }
235
236         hidg->req->status   = 0;
237         hidg->req->zero     = 0;
238         hidg->req->length   = count;
239         hidg->req->complete = f_hidg_req_complete;
240         hidg->req->context  = hidg;
241         hidg->write_pending = 1;
242
243         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
244         if (status < 0) {
245                 ERROR(hidg->func.config->cdev,
246                         "usb_ep_queue error on int endpoint %zd\n", status);
247                 hidg->write_pending = 0;
248                 wake_up(&hidg->write_queue);
249         } else {
250                 status = count;
251         }
252
253         mutex_unlock(&hidg->lock);
254
255         return status;
256 }
257
258 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
259 {
260         struct f_hidg   *hidg  = (struct f_hidg *)file->private_data;
261         unsigned int    ret = 0;
262
263         poll_wait(file, &hidg->read_queue, wait);
264         poll_wait(file, &hidg->write_queue, wait);
265
266         if (WRITE_COND)
267                 ret |= POLLOUT | POLLWRNORM;
268
269         if (READ_COND)
270                 ret |= POLLIN | POLLRDNORM;
271
272         return ret;
273 }
274
275 #undef WRITE_COND
276 #undef READ_COND
277
278 static int f_hidg_release(struct inode *inode, struct file *fd)
279 {
280         fd->private_data = NULL;
281         return 0;
282 }
283
284 static int f_hidg_open(struct inode *inode, struct file *fd)
285 {
286         struct f_hidg *hidg =
287                 container_of(inode->i_cdev, struct f_hidg, cdev);
288
289         fd->private_data = hidg;
290
291         return 0;
292 }
293
294 /*-------------------------------------------------------------------------*/
295 /*                                usb_function                             */
296
297 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
298 {
299         struct f_hidg *hidg = (struct f_hidg *)req->context;
300
301         if (req->status != 0 || req->buf == NULL || req->actual == 0) {
302                 ERROR(hidg->func.config->cdev, "%s FAILED\n", __func__);
303                 return;
304         }
305
306         spin_lock(&hidg->spinlock);
307
308         hidg->set_report_buff = krealloc(hidg->set_report_buff,
309                                          req->actual, GFP_ATOMIC);
310
311         if (hidg->set_report_buff == NULL) {
312                 spin_unlock(&hidg->spinlock);
313                 return;
314         }
315         hidg->set_report_length = req->actual;
316         memcpy(hidg->set_report_buff, req->buf, req->actual);
317
318         spin_unlock(&hidg->spinlock);
319
320         wake_up(&hidg->read_queue);
321
322         return;
323 }
324
325 static int hidg_setup(struct usb_function *f,
326                 const struct usb_ctrlrequest *ctrl)
327 {
328         struct f_hidg                   *hidg = func_to_hidg(f);
329         struct usb_composite_dev        *cdev = f->config->cdev;
330         struct usb_request              *req  = cdev->req;
331         int status = 0;
332         __u16 value, length;
333
334         value   = __le16_to_cpu(ctrl->wValue);
335         length  = __le16_to_cpu(ctrl->wLength);
336
337         VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
338                 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
339
340         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
341         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
342                   | HID_REQ_GET_REPORT):
343                 VDBG(cdev, "get_report\n");
344
345                 /* send an empty report */
346                 length = min_t(unsigned, length, hidg->report_length);
347                 memset(req->buf, 0x0, length);
348
349                 goto respond;
350                 break;
351
352         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
353                   | HID_REQ_GET_PROTOCOL):
354                 VDBG(cdev, "get_protocol\n");
355                 goto stall;
356                 break;
357
358         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
359                   | HID_REQ_SET_REPORT):
360                 VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
361                 req->context  = hidg;
362                 req->complete = hidg_set_report_complete;
363                 goto respond;
364                 break;
365
366         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
367                   | HID_REQ_SET_PROTOCOL):
368                 VDBG(cdev, "set_protocol\n");
369                 goto stall;
370                 break;
371
372         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
373                   | USB_REQ_GET_DESCRIPTOR):
374                 switch (value >> 8) {
375                 case HID_DT_REPORT:
376                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
377                         length = min_t(unsigned short, length,
378                                                    hidg->report_desc_length);
379                         memcpy(req->buf, hidg->report_desc, length);
380                         goto respond;
381                         break;
382
383                 default:
384                         VDBG(cdev, "Unknown decriptor request 0x%x\n",
385                                  value >> 8);
386                         goto stall;
387                         break;
388                 }
389                 break;
390
391         default:
392                 VDBG(cdev, "Unknown request 0x%x\n",
393                          ctrl->bRequest);
394                 goto stall;
395                 break;
396         }
397
398 stall:
399         return -EOPNOTSUPP;
400
401 respond:
402         req->zero = 0;
403         req->length = length;
404         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
405         if (status < 0)
406                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
407         return status;
408 }
409
410 static void hidg_disable(struct usb_function *f)
411 {
412         struct f_hidg *hidg = func_to_hidg(f);
413
414         usb_ep_disable(hidg->in_ep);
415         hidg->in_ep->driver_data = NULL;
416
417         return;
418 }
419
420 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
421 {
422         struct usb_composite_dev                *cdev = f->config->cdev;
423         struct f_hidg                           *hidg = func_to_hidg(f);
424         const struct usb_endpoint_descriptor    *ep_desc;
425         int status = 0;
426
427         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
428
429         if (hidg->in_ep != NULL) {
430                 /* restart endpoint */
431                 if (hidg->in_ep->driver_data != NULL)
432                         usb_ep_disable(hidg->in_ep);
433
434                 ep_desc = ep_choose(f->config->cdev->gadget,
435                                 hidg->hs_in_ep_desc, hidg->fs_in_ep_desc);
436                 status = usb_ep_enable(hidg->in_ep, ep_desc);
437                 if (status < 0) {
438                         ERROR(cdev, "Enable endpoint FAILED!\n");
439                         goto fail;
440                 }
441                 hidg->in_ep->driver_data = hidg;
442         }
443 fail:
444         return status;
445 }
446
447 const struct file_operations f_hidg_fops = {
448         .owner          = THIS_MODULE,
449         .open           = f_hidg_open,
450         .release        = f_hidg_release,
451         .write          = f_hidg_write,
452         .read           = f_hidg_read,
453         .poll           = f_hidg_poll,
454 };
455
456 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
457 {
458         struct usb_ep           *ep;
459         struct f_hidg           *hidg = func_to_hidg(f);
460         int                     status;
461         dev_t                   dev;
462
463         /* allocate instance-specific interface IDs, and patch descriptors */
464         status = usb_interface_id(c, f);
465         if (status < 0)
466                 goto fail;
467         hidg_interface_desc.bInterfaceNumber = status;
468
469
470         /* allocate instance-specific endpoints */
471         status = -ENODEV;
472         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
473         if (!ep)
474                 goto fail;
475         ep->driver_data = c->cdev;      /* claim */
476         hidg->in_ep = ep;
477
478         /* preallocate request and buffer */
479         status = -ENOMEM;
480         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
481         if (!hidg->req)
482                 goto fail;
483
484
485         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
486         if (!hidg->req->buf)
487                 goto fail;
488
489         /* set descriptor dynamic values */
490         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
491         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
492         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
493         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
494         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
495         hidg_desc.desc[0].wDescriptorLength =
496                 cpu_to_le16(hidg->report_desc_length);
497
498         hidg->set_report_buff = NULL;
499
500         /* copy descriptors */
501         f->descriptors = usb_copy_descriptors(hidg_fs_descriptors);
502         if (!f->descriptors)
503                 goto fail;
504
505         hidg->fs_in_ep_desc = usb_find_endpoint(hidg_fs_descriptors,
506                                                 f->descriptors,
507                                                 &hidg_fs_in_ep_desc);
508
509         if (gadget_is_dualspeed(c->cdev->gadget)) {
510                 hidg_hs_in_ep_desc.bEndpointAddress =
511                         hidg_fs_in_ep_desc.bEndpointAddress;
512                 f->hs_descriptors = usb_copy_descriptors(hidg_hs_descriptors);
513                 if (!f->hs_descriptors)
514                         goto fail;
515                 hidg->hs_in_ep_desc = usb_find_endpoint(hidg_hs_descriptors,
516                                                         f->hs_descriptors,
517                                                         &hidg_hs_in_ep_desc);
518         } else {
519                 hidg->hs_in_ep_desc = NULL;
520         }
521
522         mutex_init(&hidg->lock);
523         spin_lock_init(&hidg->spinlock);
524         init_waitqueue_head(&hidg->write_queue);
525         init_waitqueue_head(&hidg->read_queue);
526
527         /* create char device */
528         cdev_init(&hidg->cdev, &f_hidg_fops);
529         dev = MKDEV(major, hidg->minor);
530         status = cdev_add(&hidg->cdev, dev, 1);
531         if (status)
532                 goto fail;
533
534         device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
535
536         return 0;
537
538 fail:
539         ERROR(f->config->cdev, "hidg_bind FAILED\n");
540         if (hidg->req != NULL) {
541                 kfree(hidg->req->buf);
542                 if (hidg->in_ep != NULL)
543                         usb_ep_free_request(hidg->in_ep, hidg->req);
544         }
545
546         usb_free_descriptors(f->hs_descriptors);
547         usb_free_descriptors(f->descriptors);
548
549         return status;
550 }
551
552 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
553 {
554         struct f_hidg *hidg = func_to_hidg(f);
555
556         device_destroy(hidg_class, MKDEV(major, hidg->minor));
557         cdev_del(&hidg->cdev);
558
559         /* disable/free request and end point */
560         usb_ep_disable(hidg->in_ep);
561         usb_ep_dequeue(hidg->in_ep, hidg->req);
562         kfree(hidg->req->buf);
563         usb_ep_free_request(hidg->in_ep, hidg->req);
564
565         /* free descriptors copies */
566         usb_free_descriptors(f->hs_descriptors);
567         usb_free_descriptors(f->descriptors);
568
569         kfree(hidg->report_desc);
570         kfree(hidg->set_report_buff);
571         kfree(hidg);
572 }
573
574 /*-------------------------------------------------------------------------*/
575 /*                                 Strings                                 */
576
577 #define CT_FUNC_HID_IDX 0
578
579 static struct usb_string ct_func_string_defs[] = {
580         [CT_FUNC_HID_IDX].s     = "HID Interface",
581         {},                     /* end of list */
582 };
583
584 static struct usb_gadget_strings ct_func_string_table = {
585         .language       = 0x0409,       /* en-US */
586         .strings        = ct_func_string_defs,
587 };
588
589 static struct usb_gadget_strings *ct_func_strings[] = {
590         &ct_func_string_table,
591         NULL,
592 };
593
594 /*-------------------------------------------------------------------------*/
595 /*                             usb_configuration                           */
596
597 int __init hidg_bind_config(struct usb_configuration *c,
598                             struct hidg_func_descriptor *fdesc, int index)
599 {
600         struct f_hidg *hidg;
601         int status;
602
603         if (index >= minors)
604                 return -ENOENT;
605
606         /* maybe allocate device-global string IDs, and patch descriptors */
607         if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
608                 status = usb_string_id(c->cdev);
609                 if (status < 0)
610                         return status;
611                 ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
612                 hidg_interface_desc.iInterface = status;
613         }
614
615         /* allocate and initialize one new instance */
616         hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
617         if (!hidg)
618                 return -ENOMEM;
619
620         hidg->minor = index;
621         hidg->bInterfaceSubClass = fdesc->subclass;
622         hidg->bInterfaceProtocol = fdesc->protocol;
623         hidg->report_length = fdesc->report_length;
624         hidg->report_desc_length = fdesc->report_desc_length;
625         hidg->report_desc = kmemdup(fdesc->report_desc,
626                                     fdesc->report_desc_length,
627                                     GFP_KERNEL);
628         if (!hidg->report_desc) {
629                 kfree(hidg);
630                 return -ENOMEM;
631         }
632
633         hidg->func.name    = "hid";
634         hidg->func.strings = ct_func_strings;
635         hidg->func.bind    = hidg_bind;
636         hidg->func.unbind  = hidg_unbind;
637         hidg->func.set_alt = hidg_set_alt;
638         hidg->func.disable = hidg_disable;
639         hidg->func.setup   = hidg_setup;
640
641         status = usb_add_function(c, &hidg->func);
642         if (status)
643                 kfree(hidg);
644
645         return status;
646 }
647
648 int __init ghid_setup(struct usb_gadget *g, int count)
649 {
650         int status;
651         dev_t dev;
652
653         hidg_class = class_create(THIS_MODULE, "hidg");
654
655         status = alloc_chrdev_region(&dev, 0, count, "hidg");
656         if (!status) {
657                 major = MAJOR(dev);
658                 minors = count;
659         }
660
661         return status;
662 }
663
664 void ghid_cleanup(void)
665 {
666         if (major) {
667                 unregister_chrdev_region(MKDEV(major, 0), minors);
668                 major = minors = 0;
669         }
670
671         class_destroy(hidg_class);
672         hidg_class = NULL;
673 }