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
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/hid.h>
15 #include <linux/idr.h>
16 #include <linux/cdev.h>
17 #include <linux/mutex.h>
18 #include <linux/poll.h>
19 #include <linux/uaccess.h>
20 #include <linux/wait.h>
21 #include <linux/sched.h>
22 #include <linux/usb/g_hid.h>
23
24 #include "u_f.h"
25 #include "u_hid.h"
26
27 #define HIDG_MINORS 4
28
29 static int major, minors;
30 static struct class *hidg_class;
31 static DEFINE_IDA(hidg_ida);
32 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
33
34 /*-------------------------------------------------------------------------*/
35 /* HID gadget struct */
36
37 struct f_hidg_req_list {
38 struct usb_request *req;
39 unsigned int pos;
40 struct list_head list;
41 };
42
43 struct f_hidg {
44 /* configuration */
45 unsigned char bInterfaceSubClass;
46 unsigned char bInterfaceProtocol;
47 unsigned short report_desc_length;
48 char *report_desc;
49 unsigned short report_length;
50
51 /* recv report */
52 struct list_head completed_out_req;
53 spinlock_t spinlock;
54 wait_queue_head_t read_queue;
55 unsigned int qlen;
56
57 /* send report */
58 struct mutex lock;
59 bool write_pending;
60 wait_queue_head_t write_queue;
61 struct usb_request *req;
62
63 int minor;
64 struct cdev cdev;
65 struct usb_function func;
66
67 struct usb_ep *in_ep;
68 struct usb_ep *out_ep;
69 };
70
func_to_hidg(struct usb_function * f)71 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
72 {
73 return container_of(f, struct f_hidg, func);
74 }
75
76 /*-------------------------------------------------------------------------*/
77 /* Static descriptors */
78
79 static struct usb_interface_descriptor hidg_interface_desc = {
80 .bLength = sizeof hidg_interface_desc,
81 .bDescriptorType = USB_DT_INTERFACE,
82 /* .bInterfaceNumber = DYNAMIC */
83 .bAlternateSetting = 0,
84 .bNumEndpoints = 2,
85 .bInterfaceClass = USB_CLASS_HID,
86 /* .bInterfaceSubClass = DYNAMIC */
87 /* .bInterfaceProtocol = DYNAMIC */
88 /* .iInterface = DYNAMIC */
89 };
90
91 static struct hid_descriptor hidg_desc = {
92 .bLength = sizeof hidg_desc,
93 .bDescriptorType = HID_DT_HID,
94 .bcdHID = cpu_to_le16(0x0101),
95 .bCountryCode = 0x00,
96 .bNumDescriptors = 0x1,
97 /*.desc[0].bDescriptorType = DYNAMIC */
98 /*.desc[0].wDescriptorLenght = DYNAMIC */
99 };
100
101 /* High-Speed Support */
102
103 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
104 .bLength = USB_DT_ENDPOINT_SIZE,
105 .bDescriptorType = USB_DT_ENDPOINT,
106 .bEndpointAddress = USB_DIR_IN,
107 .bmAttributes = USB_ENDPOINT_XFER_INT,
108 /*.wMaxPacketSize = DYNAMIC */
109 .bInterval = 4, /* FIXME: Add this field in the
110 * HID gadget configuration?
111 * (struct hidg_func_descriptor)
112 */
113 };
114
115 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
116 .bLength = USB_DT_ENDPOINT_SIZE,
117 .bDescriptorType = USB_DT_ENDPOINT,
118 .bEndpointAddress = USB_DIR_OUT,
119 .bmAttributes = USB_ENDPOINT_XFER_INT,
120 /*.wMaxPacketSize = DYNAMIC */
121 .bInterval = 4, /* FIXME: Add this field in the
122 * HID gadget configuration?
123 * (struct hidg_func_descriptor)
124 */
125 };
126
127 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
128 (struct usb_descriptor_header *)&hidg_interface_desc,
129 (struct usb_descriptor_header *)&hidg_desc,
130 (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
131 (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
132 NULL,
133 };
134
135 /* Full-Speed Support */
136
137 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
138 .bLength = USB_DT_ENDPOINT_SIZE,
139 .bDescriptorType = USB_DT_ENDPOINT,
140 .bEndpointAddress = USB_DIR_IN,
141 .bmAttributes = USB_ENDPOINT_XFER_INT,
142 /*.wMaxPacketSize = DYNAMIC */
143 .bInterval = 10, /* FIXME: Add this field in the
144 * HID gadget configuration?
145 * (struct hidg_func_descriptor)
146 */
147 };
148
149 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
150 .bLength = USB_DT_ENDPOINT_SIZE,
151 .bDescriptorType = USB_DT_ENDPOINT,
152 .bEndpointAddress = USB_DIR_OUT,
153 .bmAttributes = USB_ENDPOINT_XFER_INT,
154 /*.wMaxPacketSize = DYNAMIC */
155 .bInterval = 10, /* FIXME: Add this field in the
156 * HID gadget configuration?
157 * (struct hidg_func_descriptor)
158 */
159 };
160
161 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
162 (struct usb_descriptor_header *)&hidg_interface_desc,
163 (struct usb_descriptor_header *)&hidg_desc,
164 (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
165 (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
166 NULL,
167 };
168
169 /*-------------------------------------------------------------------------*/
170 /* Strings */
171
172 #define CT_FUNC_HID_IDX 0
173
174 static struct usb_string ct_func_string_defs[] = {
175 [CT_FUNC_HID_IDX].s = "HID Interface",
176 {}, /* end of list */
177 };
178
179 static struct usb_gadget_strings ct_func_string_table = {
180 .language = 0x0409, /* en-US */
181 .strings = ct_func_string_defs,
182 };
183
184 static struct usb_gadget_strings *ct_func_strings[] = {
185 &ct_func_string_table,
186 NULL,
187 };
188
189 /*-------------------------------------------------------------------------*/
190 /* Char Device */
191
f_hidg_read(struct file * file,char __user * buffer,size_t count,loff_t * ptr)192 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
193 size_t count, loff_t *ptr)
194 {
195 struct f_hidg *hidg = file->private_data;
196 struct f_hidg_req_list *list;
197 struct usb_request *req;
198 unsigned long flags;
199 int ret;
200
201 if (!count)
202 return 0;
203
204 if (!access_ok(VERIFY_WRITE, buffer, count))
205 return -EFAULT;
206
207 spin_lock_irqsave(&hidg->spinlock, flags);
208
209 #define READ_COND (!list_empty(&hidg->completed_out_req))
210
211 /* wait for at least one buffer to complete */
212 while (!READ_COND) {
213 spin_unlock_irqrestore(&hidg->spinlock, flags);
214 if (file->f_flags & O_NONBLOCK)
215 return -EAGAIN;
216
217 if (wait_event_interruptible(hidg->read_queue, READ_COND))
218 return -ERESTARTSYS;
219
220 spin_lock_irqsave(&hidg->spinlock, flags);
221 }
222
223 /* pick the first one */
224 list = list_first_entry(&hidg->completed_out_req,
225 struct f_hidg_req_list, list);
226
227 /*
228 * Remove this from list to protect it from beign free()
229 * while host disables our function
230 */
231 list_del(&list->list);
232
233 req = list->req;
234 count = min_t(unsigned int, count, req->actual - list->pos);
235 spin_unlock_irqrestore(&hidg->spinlock, flags);
236
237 /* copy to user outside spinlock */
238 count -= copy_to_user(buffer, req->buf + list->pos, count);
239 list->pos += count;
240
241 /*
242 * if this request is completely handled and transfered to
243 * userspace, remove its entry from the list and requeue it
244 * again. Otherwise, we will revisit it again upon the next
245 * call, taking into account its current read position.
246 */
247 if (list->pos == req->actual) {
248 kfree(list);
249
250 req->length = hidg->report_length;
251 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
252 if (ret < 0) {
253 free_ep_req(hidg->out_ep, req);
254 return ret;
255 }
256 } else {
257 spin_lock_irqsave(&hidg->spinlock, flags);
258 list_add(&list->list, &hidg->completed_out_req);
259 spin_unlock_irqrestore(&hidg->spinlock, flags);
260
261 wake_up(&hidg->read_queue);
262 }
263
264 return count;
265 }
266
f_hidg_req_complete(struct usb_ep * ep,struct usb_request * req)267 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
268 {
269 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
270
271 if (req->status != 0) {
272 ERROR(hidg->func.config->cdev,
273 "End Point Request ERROR: %d\n", req->status);
274 }
275
276 hidg->write_pending = 0;
277 wake_up(&hidg->write_queue);
278 }
279
f_hidg_write(struct file * file,const char __user * buffer,size_t count,loff_t * offp)280 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
281 size_t count, loff_t *offp)
282 {
283 struct f_hidg *hidg = file->private_data;
284 ssize_t status = -ENOMEM;
285
286 if (!access_ok(VERIFY_READ, buffer, count))
287 return -EFAULT;
288
289 mutex_lock(&hidg->lock);
290
291 #define WRITE_COND (!hidg->write_pending)
292
293 /* write queue */
294 while (!WRITE_COND) {
295 mutex_unlock(&hidg->lock);
296 if (file->f_flags & O_NONBLOCK)
297 return -EAGAIN;
298
299 if (wait_event_interruptible_exclusive(
300 hidg->write_queue, WRITE_COND))
301 return -ERESTARTSYS;
302
303 mutex_lock(&hidg->lock);
304 }
305
306 count = min_t(unsigned, count, hidg->report_length);
307 status = copy_from_user(hidg->req->buf, buffer, count);
308
309 if (status != 0) {
310 ERROR(hidg->func.config->cdev,
311 "copy_from_user error\n");
312 mutex_unlock(&hidg->lock);
313 return -EINVAL;
314 }
315
316 hidg->req->status = 0;
317 hidg->req->zero = 0;
318 hidg->req->length = count;
319 hidg->req->complete = f_hidg_req_complete;
320 hidg->req->context = hidg;
321 hidg->write_pending = 1;
322
323 status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
324 if (status < 0) {
325 ERROR(hidg->func.config->cdev,
326 "usb_ep_queue error on int endpoint %zd\n", status);
327 hidg->write_pending = 0;
328 wake_up(&hidg->write_queue);
329 } else {
330 status = count;
331 }
332
333 mutex_unlock(&hidg->lock);
334
335 return status;
336 }
337
f_hidg_poll(struct file * file,poll_table * wait)338 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
339 {
340 struct f_hidg *hidg = file->private_data;
341 unsigned int ret = 0;
342
343 poll_wait(file, &hidg->read_queue, wait);
344 poll_wait(file, &hidg->write_queue, wait);
345
346 if (WRITE_COND)
347 ret |= POLLOUT | POLLWRNORM;
348
349 if (READ_COND)
350 ret |= POLLIN | POLLRDNORM;
351
352 return ret;
353 }
354
355 #undef WRITE_COND
356 #undef READ_COND
357
f_hidg_release(struct inode * inode,struct file * fd)358 static int f_hidg_release(struct inode *inode, struct file *fd)
359 {
360 fd->private_data = NULL;
361 return 0;
362 }
363
f_hidg_open(struct inode * inode,struct file * fd)364 static int f_hidg_open(struct inode *inode, struct file *fd)
365 {
366 struct f_hidg *hidg =
367 container_of(inode->i_cdev, struct f_hidg, cdev);
368
369 fd->private_data = hidg;
370
371 return 0;
372 }
373
374 /*-------------------------------------------------------------------------*/
375 /* usb_function */
376
hidg_alloc_ep_req(struct usb_ep * ep,unsigned length)377 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
378 unsigned length)
379 {
380 return alloc_ep_req(ep, length, length);
381 }
382
hidg_set_report_complete(struct usb_ep * ep,struct usb_request * req)383 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
384 {
385 struct f_hidg *hidg = (struct f_hidg *) req->context;
386 struct f_hidg_req_list *req_list;
387 unsigned long flags;
388
389 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
390 if (!req_list)
391 return;
392
393 req_list->req = req;
394
395 spin_lock_irqsave(&hidg->spinlock, flags);
396 list_add_tail(&req_list->list, &hidg->completed_out_req);
397 spin_unlock_irqrestore(&hidg->spinlock, flags);
398
399 wake_up(&hidg->read_queue);
400 }
401
hidg_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)402 static int hidg_setup(struct usb_function *f,
403 const struct usb_ctrlrequest *ctrl)
404 {
405 struct f_hidg *hidg = func_to_hidg(f);
406 struct usb_composite_dev *cdev = f->config->cdev;
407 struct usb_request *req = cdev->req;
408 int status = 0;
409 __u16 value, length;
410
411 value = __le16_to_cpu(ctrl->wValue);
412 length = __le16_to_cpu(ctrl->wLength);
413
414 VDBG(cdev,
415 "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
416 __func__, ctrl->bRequestType, ctrl->bRequest, value);
417
418 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
419 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
420 | HID_REQ_GET_REPORT):
421 VDBG(cdev, "get_report\n");
422
423 /* send an empty report */
424 length = min_t(unsigned, length, hidg->report_length);
425 memset(req->buf, 0x0, length);
426
427 goto respond;
428 break;
429
430 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
431 | HID_REQ_GET_PROTOCOL):
432 VDBG(cdev, "get_protocol\n");
433 goto stall;
434 break;
435
436 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
437 | HID_REQ_SET_REPORT):
438 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
439 goto stall;
440 break;
441
442 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
443 | HID_REQ_SET_PROTOCOL):
444 VDBG(cdev, "set_protocol\n");
445 goto stall;
446 break;
447
448 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
449 | USB_REQ_GET_DESCRIPTOR):
450 switch (value >> 8) {
451 case HID_DT_HID:
452 {
453 struct hid_descriptor hidg_desc_copy = hidg_desc;
454
455 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
456 hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
457 hidg_desc_copy.desc[0].wDescriptorLength =
458 cpu_to_le16(hidg->report_desc_length);
459
460 length = min_t(unsigned short, length,
461 hidg_desc_copy.bLength);
462 memcpy(req->buf, &hidg_desc_copy, length);
463 goto respond;
464 break;
465 }
466 case HID_DT_REPORT:
467 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
468 length = min_t(unsigned short, length,
469 hidg->report_desc_length);
470 memcpy(req->buf, hidg->report_desc, length);
471 goto respond;
472 break;
473
474 default:
475 VDBG(cdev, "Unknown descriptor request 0x%x\n",
476 value >> 8);
477 goto stall;
478 break;
479 }
480 break;
481
482 default:
483 VDBG(cdev, "Unknown request 0x%x\n",
484 ctrl->bRequest);
485 goto stall;
486 break;
487 }
488
489 stall:
490 return -EOPNOTSUPP;
491
492 respond:
493 req->zero = 0;
494 req->length = length;
495 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
496 if (status < 0)
497 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
498 return status;
499 }
500
hidg_disable(struct usb_function * f)501 static void hidg_disable(struct usb_function *f)
502 {
503 struct f_hidg *hidg = func_to_hidg(f);
504 struct f_hidg_req_list *list, *next;
505 unsigned long flags;
506
507 usb_ep_disable(hidg->in_ep);
508 usb_ep_disable(hidg->out_ep);
509
510 spin_lock_irqsave(&hidg->spinlock, flags);
511 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
512 free_ep_req(hidg->out_ep, list->req);
513 list_del(&list->list);
514 kfree(list);
515 }
516 spin_unlock_irqrestore(&hidg->spinlock, flags);
517 }
518
hidg_set_alt(struct usb_function * f,unsigned intf,unsigned alt)519 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
520 {
521 struct usb_composite_dev *cdev = f->config->cdev;
522 struct f_hidg *hidg = func_to_hidg(f);
523 int i, status = 0;
524
525 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
526
527 if (hidg->in_ep != NULL) {
528 /* restart endpoint */
529 usb_ep_disable(hidg->in_ep);
530
531 status = config_ep_by_speed(f->config->cdev->gadget, f,
532 hidg->in_ep);
533 if (status) {
534 ERROR(cdev, "config_ep_by_speed FAILED!\n");
535 goto fail;
536 }
537 status = usb_ep_enable(hidg->in_ep);
538 if (status < 0) {
539 ERROR(cdev, "Enable IN endpoint FAILED!\n");
540 goto fail;
541 }
542 hidg->in_ep->driver_data = hidg;
543 }
544
545
546 if (hidg->out_ep != NULL) {
547 /* restart endpoint */
548 usb_ep_disable(hidg->out_ep);
549
550 status = config_ep_by_speed(f->config->cdev->gadget, f,
551 hidg->out_ep);
552 if (status) {
553 ERROR(cdev, "config_ep_by_speed FAILED!\n");
554 goto fail;
555 }
556 status = usb_ep_enable(hidg->out_ep);
557 if (status < 0) {
558 ERROR(cdev, "Enable OUT endpoint FAILED!\n");
559 goto fail;
560 }
561 hidg->out_ep->driver_data = hidg;
562
563 /*
564 * allocate a bunch of read buffers and queue them all at once.
565 */
566 for (i = 0; i < hidg->qlen && status == 0; i++) {
567 struct usb_request *req =
568 hidg_alloc_ep_req(hidg->out_ep,
569 hidg->report_length);
570 if (req) {
571 req->complete = hidg_set_report_complete;
572 req->context = hidg;
573 status = usb_ep_queue(hidg->out_ep, req,
574 GFP_ATOMIC);
575 if (status)
576 ERROR(cdev, "%s queue req --> %d\n",
577 hidg->out_ep->name, status);
578 } else {
579 usb_ep_disable(hidg->out_ep);
580 status = -ENOMEM;
581 goto fail;
582 }
583 }
584 }
585
586 fail:
587 return status;
588 }
589
590 static const struct file_operations f_hidg_fops = {
591 .owner = THIS_MODULE,
592 .open = f_hidg_open,
593 .release = f_hidg_release,
594 .write = f_hidg_write,
595 .read = f_hidg_read,
596 .poll = f_hidg_poll,
597 .llseek = noop_llseek,
598 };
599
hidg_bind(struct usb_configuration * c,struct usb_function * f)600 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
601 {
602 struct usb_ep *ep;
603 struct f_hidg *hidg = func_to_hidg(f);
604 struct usb_string *us;
605 struct device *device;
606 int status;
607 dev_t dev;
608
609 /* maybe allocate device-global string IDs, and patch descriptors */
610 us = usb_gstrings_attach(c->cdev, ct_func_strings,
611 ARRAY_SIZE(ct_func_string_defs));
612 if (IS_ERR(us))
613 return PTR_ERR(us);
614 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
615
616 /* allocate instance-specific interface IDs, and patch descriptors */
617 status = usb_interface_id(c, f);
618 if (status < 0)
619 goto fail;
620 hidg_interface_desc.bInterfaceNumber = status;
621
622 /* allocate instance-specific endpoints */
623 status = -ENODEV;
624 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
625 if (!ep)
626 goto fail;
627 hidg->in_ep = ep;
628
629 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
630 if (!ep)
631 goto fail;
632 hidg->out_ep = ep;
633
634 /* preallocate request and buffer */
635 status = -ENOMEM;
636 hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
637 if (!hidg->req)
638 goto fail;
639
640 hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
641 if (!hidg->req->buf)
642 goto fail;
643
644 /* set descriptor dynamic values */
645 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
646 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
647 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
648 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
649 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
650 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
651 /*
652 * We can use hidg_desc struct here but we should not relay
653 * that its content won't change after returning from this function.
654 */
655 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
656 hidg_desc.desc[0].wDescriptorLength =
657 cpu_to_le16(hidg->report_desc_length);
658
659 hidg_hs_in_ep_desc.bEndpointAddress =
660 hidg_fs_in_ep_desc.bEndpointAddress;
661 hidg_hs_out_ep_desc.bEndpointAddress =
662 hidg_fs_out_ep_desc.bEndpointAddress;
663
664 status = usb_assign_descriptors(f, hidg_fs_descriptors,
665 hidg_hs_descriptors, NULL);
666 if (status)
667 goto fail;
668
669 mutex_init(&hidg->lock);
670 spin_lock_init(&hidg->spinlock);
671 init_waitqueue_head(&hidg->write_queue);
672 init_waitqueue_head(&hidg->read_queue);
673 INIT_LIST_HEAD(&hidg->completed_out_req);
674
675 /* create char device */
676 cdev_init(&hidg->cdev, &f_hidg_fops);
677 dev = MKDEV(major, hidg->minor);
678 status = cdev_add(&hidg->cdev, dev, 1);
679 if (status)
680 goto fail_free_descs;
681
682 device = device_create(hidg_class, NULL, dev, NULL,
683 "%s%d", "hidg", hidg->minor);
684 if (IS_ERR(device)) {
685 status = PTR_ERR(device);
686 goto del;
687 }
688
689 return 0;
690 del:
691 cdev_del(&hidg->cdev);
692 fail_free_descs:
693 usb_free_all_descriptors(f);
694 fail:
695 ERROR(f->config->cdev, "hidg_bind FAILED\n");
696 if (hidg->req != NULL) {
697 kfree(hidg->req->buf);
698 if (hidg->in_ep != NULL)
699 usb_ep_free_request(hidg->in_ep, hidg->req);
700 }
701
702 return status;
703 }
704
hidg_get_minor(void)705 static inline int hidg_get_minor(void)
706 {
707 int ret;
708
709 ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
710 if (ret >= HIDG_MINORS) {
711 ida_simple_remove(&hidg_ida, ret);
712 ret = -ENODEV;
713 }
714
715 return ret;
716 }
717
to_f_hid_opts(struct config_item * item)718 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
719 {
720 return container_of(to_config_group(item), struct f_hid_opts,
721 func_inst.group);
722 }
723
hid_attr_release(struct config_item * item)724 static void hid_attr_release(struct config_item *item)
725 {
726 struct f_hid_opts *opts = to_f_hid_opts(item);
727
728 usb_put_function_instance(&opts->func_inst);
729 }
730
731 static struct configfs_item_operations hidg_item_ops = {
732 .release = hid_attr_release,
733 };
734
735 #define F_HID_OPT(name, prec, limit) \
736 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
737 { \
738 struct f_hid_opts *opts = to_f_hid_opts(item); \
739 int result; \
740 \
741 mutex_lock(&opts->lock); \
742 result = sprintf(page, "%d\n", opts->name); \
743 mutex_unlock(&opts->lock); \
744 \
745 return result; \
746 } \
747 \
748 static ssize_t f_hid_opts_##name##_store(struct config_item *item, \
749 const char *page, size_t len) \
750 { \
751 struct f_hid_opts *opts = to_f_hid_opts(item); \
752 int ret; \
753 u##prec num; \
754 \
755 mutex_lock(&opts->lock); \
756 if (opts->refcnt) { \
757 ret = -EBUSY; \
758 goto end; \
759 } \
760 \
761 ret = kstrtou##prec(page, 0, &num); \
762 if (ret) \
763 goto end; \
764 \
765 if (num > limit) { \
766 ret = -EINVAL; \
767 goto end; \
768 } \
769 opts->name = num; \
770 ret = len; \
771 \
772 end: \
773 mutex_unlock(&opts->lock); \
774 return ret; \
775 } \
776 \
777 CONFIGFS_ATTR(f_hid_opts_, name)
778
779 F_HID_OPT(subclass, 8, 255);
780 F_HID_OPT(protocol, 8, 255);
781 F_HID_OPT(report_length, 16, 65535);
782
f_hid_opts_report_desc_show(struct config_item * item,char * page)783 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
784 {
785 struct f_hid_opts *opts = to_f_hid_opts(item);
786 int result;
787
788 mutex_lock(&opts->lock);
789 result = opts->report_desc_length;
790 memcpy(page, opts->report_desc, opts->report_desc_length);
791 mutex_unlock(&opts->lock);
792
793 return result;
794 }
795
f_hid_opts_report_desc_store(struct config_item * item,const char * page,size_t len)796 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
797 const char *page, size_t len)
798 {
799 struct f_hid_opts *opts = to_f_hid_opts(item);
800 int ret = -EBUSY;
801 char *d;
802
803 mutex_lock(&opts->lock);
804
805 if (opts->refcnt)
806 goto end;
807 if (len > PAGE_SIZE) {
808 ret = -ENOSPC;
809 goto end;
810 }
811 d = kmemdup(page, len, GFP_KERNEL);
812 if (!d) {
813 ret = -ENOMEM;
814 goto end;
815 }
816 kfree(opts->report_desc);
817 opts->report_desc = d;
818 opts->report_desc_length = len;
819 opts->report_desc_alloc = true;
820 ret = len;
821 end:
822 mutex_unlock(&opts->lock);
823 return ret;
824 }
825
826 CONFIGFS_ATTR(f_hid_opts_, report_desc);
827
828 static struct configfs_attribute *hid_attrs[] = {
829 &f_hid_opts_attr_subclass,
830 &f_hid_opts_attr_protocol,
831 &f_hid_opts_attr_report_length,
832 &f_hid_opts_attr_report_desc,
833 NULL,
834 };
835
836 static struct config_item_type hid_func_type = {
837 .ct_item_ops = &hidg_item_ops,
838 .ct_attrs = hid_attrs,
839 .ct_owner = THIS_MODULE,
840 };
841
hidg_put_minor(int minor)842 static inline void hidg_put_minor(int minor)
843 {
844 ida_simple_remove(&hidg_ida, minor);
845 }
846
hidg_free_inst(struct usb_function_instance * f)847 static void hidg_free_inst(struct usb_function_instance *f)
848 {
849 struct f_hid_opts *opts;
850
851 opts = container_of(f, struct f_hid_opts, func_inst);
852
853 mutex_lock(&hidg_ida_lock);
854
855 hidg_put_minor(opts->minor);
856 if (idr_is_empty(&hidg_ida.idr))
857 ghid_cleanup();
858
859 mutex_unlock(&hidg_ida_lock);
860
861 if (opts->report_desc_alloc)
862 kfree(opts->report_desc);
863
864 kfree(opts);
865 }
866
hidg_alloc_inst(void)867 static struct usb_function_instance *hidg_alloc_inst(void)
868 {
869 struct f_hid_opts *opts;
870 struct usb_function_instance *ret;
871 int status = 0;
872
873 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
874 if (!opts)
875 return ERR_PTR(-ENOMEM);
876 mutex_init(&opts->lock);
877 opts->func_inst.free_func_inst = hidg_free_inst;
878 ret = &opts->func_inst;
879
880 mutex_lock(&hidg_ida_lock);
881
882 if (idr_is_empty(&hidg_ida.idr)) {
883 status = ghid_setup(NULL, HIDG_MINORS);
884 if (status) {
885 ret = ERR_PTR(status);
886 kfree(opts);
887 goto unlock;
888 }
889 }
890
891 opts->minor = hidg_get_minor();
892 if (opts->minor < 0) {
893 ret = ERR_PTR(opts->minor);
894 kfree(opts);
895 if (idr_is_empty(&hidg_ida.idr))
896 ghid_cleanup();
897 goto unlock;
898 }
899 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
900
901 unlock:
902 mutex_unlock(&hidg_ida_lock);
903 return ret;
904 }
905
hidg_free(struct usb_function * f)906 static void hidg_free(struct usb_function *f)
907 {
908 struct f_hidg *hidg;
909 struct f_hid_opts *opts;
910
911 hidg = func_to_hidg(f);
912 opts = container_of(f->fi, struct f_hid_opts, func_inst);
913 kfree(hidg->report_desc);
914 kfree(hidg);
915 mutex_lock(&opts->lock);
916 --opts->refcnt;
917 mutex_unlock(&opts->lock);
918 }
919
hidg_unbind(struct usb_configuration * c,struct usb_function * f)920 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
921 {
922 struct f_hidg *hidg = func_to_hidg(f);
923
924 device_destroy(hidg_class, MKDEV(major, hidg->minor));
925 cdev_del(&hidg->cdev);
926
927 /* disable/free request and end point */
928 usb_ep_disable(hidg->in_ep);
929 kfree(hidg->req->buf);
930 usb_ep_free_request(hidg->in_ep, hidg->req);
931
932 usb_free_all_descriptors(f);
933 }
934
hidg_alloc(struct usb_function_instance * fi)935 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
936 {
937 struct f_hidg *hidg;
938 struct f_hid_opts *opts;
939
940 /* allocate and initialize one new instance */
941 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
942 if (!hidg)
943 return ERR_PTR(-ENOMEM);
944
945 opts = container_of(fi, struct f_hid_opts, func_inst);
946
947 mutex_lock(&opts->lock);
948 ++opts->refcnt;
949
950 hidg->minor = opts->minor;
951 hidg->bInterfaceSubClass = opts->subclass;
952 hidg->bInterfaceProtocol = opts->protocol;
953 hidg->report_length = opts->report_length;
954 hidg->report_desc_length = opts->report_desc_length;
955 if (opts->report_desc) {
956 hidg->report_desc = kmemdup(opts->report_desc,
957 opts->report_desc_length,
958 GFP_KERNEL);
959 if (!hidg->report_desc) {
960 kfree(hidg);
961 mutex_unlock(&opts->lock);
962 return ERR_PTR(-ENOMEM);
963 }
964 }
965
966 mutex_unlock(&opts->lock);
967
968 hidg->func.name = "hid";
969 hidg->func.bind = hidg_bind;
970 hidg->func.unbind = hidg_unbind;
971 hidg->func.set_alt = hidg_set_alt;
972 hidg->func.disable = hidg_disable;
973 hidg->func.setup = hidg_setup;
974 hidg->func.free_func = hidg_free;
975
976 /* this could me made configurable at some point */
977 hidg->qlen = 4;
978
979 return &hidg->func;
980 }
981
982 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
983 MODULE_LICENSE("GPL");
984 MODULE_AUTHOR("Fabien Chouteau");
985
ghid_setup(struct usb_gadget * g,int count)986 int ghid_setup(struct usb_gadget *g, int count)
987 {
988 int status;
989 dev_t dev;
990
991 hidg_class = class_create(THIS_MODULE, "hidg");
992 if (IS_ERR(hidg_class)) {
993 status = PTR_ERR(hidg_class);
994 hidg_class = NULL;
995 return status;
996 }
997
998 status = alloc_chrdev_region(&dev, 0, count, "hidg");
999 if (status) {
1000 class_destroy(hidg_class);
1001 hidg_class = NULL;
1002 return status;
1003 }
1004
1005 major = MAJOR(dev);
1006 minors = count;
1007
1008 return 0;
1009 }
1010
ghid_cleanup(void)1011 void ghid_cleanup(void)
1012 {
1013 if (major) {
1014 unregister_chrdev_region(MKDEV(major, 0), minors);
1015 major = minors = 0;
1016 }
1017
1018 class_destroy(hidg_class);
1019 hidg_class = NULL;
1020 }
1021