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 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 = 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 */ 191 192 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 req = list->req; 227 count = min_t(unsigned int, count, req->actual - list->pos); 228 spin_unlock_irqrestore(&hidg->spinlock, flags); 229 230 /* copy to user outside spinlock */ 231 count -= copy_to_user(buffer, req->buf + list->pos, count); 232 list->pos += count; 233 234 /* 235 * if this request is completely handled and transfered to 236 * userspace, remove its entry from the list and requeue it 237 * again. Otherwise, we will revisit it again upon the next 238 * call, taking into account its current read position. 239 */ 240 if (list->pos == req->actual) { 241 spin_lock_irqsave(&hidg->spinlock, flags); 242 list_del(&list->list); 243 kfree(list); 244 spin_unlock_irqrestore(&hidg->spinlock, flags); 245 246 req->length = hidg->report_length; 247 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL); 248 if (ret < 0) 249 return ret; 250 } 251 252 return count; 253 } 254 255 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req) 256 { 257 struct f_hidg *hidg = (struct f_hidg *)ep->driver_data; 258 259 if (req->status != 0) { 260 ERROR(hidg->func.config->cdev, 261 "End Point Request ERROR: %d\n", req->status); 262 } 263 264 hidg->write_pending = 0; 265 wake_up(&hidg->write_queue); 266 } 267 268 static ssize_t f_hidg_write(struct file *file, const char __user *buffer, 269 size_t count, loff_t *offp) 270 { 271 struct f_hidg *hidg = file->private_data; 272 ssize_t status = -ENOMEM; 273 274 if (!access_ok(VERIFY_READ, buffer, count)) 275 return -EFAULT; 276 277 mutex_lock(&hidg->lock); 278 279 #define WRITE_COND (!hidg->write_pending) 280 281 /* write queue */ 282 while (!WRITE_COND) { 283 mutex_unlock(&hidg->lock); 284 if (file->f_flags & O_NONBLOCK) 285 return -EAGAIN; 286 287 if (wait_event_interruptible_exclusive( 288 hidg->write_queue, WRITE_COND)) 289 return -ERESTARTSYS; 290 291 mutex_lock(&hidg->lock); 292 } 293 294 count = min_t(unsigned, count, hidg->report_length); 295 status = copy_from_user(hidg->req->buf, buffer, count); 296 297 if (status != 0) { 298 ERROR(hidg->func.config->cdev, 299 "copy_from_user error\n"); 300 mutex_unlock(&hidg->lock); 301 return -EINVAL; 302 } 303 304 hidg->req->status = 0; 305 hidg->req->zero = 0; 306 hidg->req->length = count; 307 hidg->req->complete = f_hidg_req_complete; 308 hidg->req->context = hidg; 309 hidg->write_pending = 1; 310 311 status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC); 312 if (status < 0) { 313 ERROR(hidg->func.config->cdev, 314 "usb_ep_queue error on int endpoint %zd\n", status); 315 hidg->write_pending = 0; 316 wake_up(&hidg->write_queue); 317 } else { 318 status = count; 319 } 320 321 mutex_unlock(&hidg->lock); 322 323 return status; 324 } 325 326 static unsigned int f_hidg_poll(struct file *file, poll_table *wait) 327 { 328 struct f_hidg *hidg = file->private_data; 329 unsigned int ret = 0; 330 331 poll_wait(file, &hidg->read_queue, wait); 332 poll_wait(file, &hidg->write_queue, wait); 333 334 if (WRITE_COND) 335 ret |= POLLOUT | POLLWRNORM; 336 337 if (READ_COND) 338 ret |= POLLIN | POLLRDNORM; 339 340 return ret; 341 } 342 343 #undef WRITE_COND 344 #undef READ_COND 345 346 static int f_hidg_release(struct inode *inode, struct file *fd) 347 { 348 fd->private_data = NULL; 349 return 0; 350 } 351 352 static int f_hidg_open(struct inode *inode, struct file *fd) 353 { 354 struct f_hidg *hidg = 355 container_of(inode->i_cdev, struct f_hidg, cdev); 356 357 fd->private_data = hidg; 358 359 return 0; 360 } 361 362 /*-------------------------------------------------------------------------*/ 363 /* usb_function */ 364 365 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep, 366 unsigned length) 367 { 368 return alloc_ep_req(ep, length, length); 369 } 370 371 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req) 372 { 373 struct f_hidg *hidg = (struct f_hidg *) req->context; 374 struct f_hidg_req_list *req_list; 375 unsigned long flags; 376 377 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC); 378 if (!req_list) 379 return; 380 381 req_list->req = req; 382 383 spin_lock_irqsave(&hidg->spinlock, flags); 384 list_add_tail(&req_list->list, &hidg->completed_out_req); 385 spin_unlock_irqrestore(&hidg->spinlock, flags); 386 387 wake_up(&hidg->read_queue); 388 } 389 390 static int hidg_setup(struct usb_function *f, 391 const struct usb_ctrlrequest *ctrl) 392 { 393 struct f_hidg *hidg = func_to_hidg(f); 394 struct usb_composite_dev *cdev = f->config->cdev; 395 struct usb_request *req = cdev->req; 396 int status = 0; 397 __u16 value, length; 398 399 value = __le16_to_cpu(ctrl->wValue); 400 length = __le16_to_cpu(ctrl->wLength); 401 402 VDBG(cdev, 403 "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n", 404 __func__, ctrl->bRequestType, ctrl->bRequest, value); 405 406 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { 407 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 408 | HID_REQ_GET_REPORT): 409 VDBG(cdev, "get_report\n"); 410 411 /* send an empty report */ 412 length = min_t(unsigned, length, hidg->report_length); 413 memset(req->buf, 0x0, length); 414 415 goto respond; 416 break; 417 418 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 419 | HID_REQ_GET_PROTOCOL): 420 VDBG(cdev, "get_protocol\n"); 421 goto stall; 422 break; 423 424 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 425 | HID_REQ_SET_REPORT): 426 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength); 427 goto stall; 428 break; 429 430 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 431 | HID_REQ_SET_PROTOCOL): 432 VDBG(cdev, "set_protocol\n"); 433 goto stall; 434 break; 435 436 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8 437 | USB_REQ_GET_DESCRIPTOR): 438 switch (value >> 8) { 439 case HID_DT_HID: 440 { 441 struct hid_descriptor hidg_desc_copy = hidg_desc; 442 443 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n"); 444 hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT; 445 hidg_desc_copy.desc[0].wDescriptorLength = 446 cpu_to_le16(hidg->report_desc_length); 447 448 length = min_t(unsigned short, length, 449 hidg_desc_copy.bLength); 450 memcpy(req->buf, &hidg_desc_copy, length); 451 goto respond; 452 break; 453 } 454 case HID_DT_REPORT: 455 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n"); 456 length = min_t(unsigned short, length, 457 hidg->report_desc_length); 458 memcpy(req->buf, hidg->report_desc, length); 459 goto respond; 460 break; 461 462 default: 463 VDBG(cdev, "Unknown descriptor request 0x%x\n", 464 value >> 8); 465 goto stall; 466 break; 467 } 468 break; 469 470 default: 471 VDBG(cdev, "Unknown request 0x%x\n", 472 ctrl->bRequest); 473 goto stall; 474 break; 475 } 476 477 stall: 478 return -EOPNOTSUPP; 479 480 respond: 481 req->zero = 0; 482 req->length = length; 483 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); 484 if (status < 0) 485 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value); 486 return status; 487 } 488 489 static void hidg_disable(struct usb_function *f) 490 { 491 struct f_hidg *hidg = func_to_hidg(f); 492 struct f_hidg_req_list *list, *next; 493 494 usb_ep_disable(hidg->in_ep); 495 usb_ep_disable(hidg->out_ep); 496 497 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) { 498 list_del(&list->list); 499 kfree(list); 500 } 501 } 502 503 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt) 504 { 505 struct usb_composite_dev *cdev = f->config->cdev; 506 struct f_hidg *hidg = func_to_hidg(f); 507 int i, status = 0; 508 509 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt); 510 511 if (hidg->in_ep != NULL) { 512 /* restart endpoint */ 513 usb_ep_disable(hidg->in_ep); 514 515 status = config_ep_by_speed(f->config->cdev->gadget, f, 516 hidg->in_ep); 517 if (status) { 518 ERROR(cdev, "config_ep_by_speed FAILED!\n"); 519 goto fail; 520 } 521 status = usb_ep_enable(hidg->in_ep); 522 if (status < 0) { 523 ERROR(cdev, "Enable IN endpoint FAILED!\n"); 524 goto fail; 525 } 526 hidg->in_ep->driver_data = hidg; 527 } 528 529 530 if (hidg->out_ep != NULL) { 531 /* restart endpoint */ 532 usb_ep_disable(hidg->out_ep); 533 534 status = config_ep_by_speed(f->config->cdev->gadget, f, 535 hidg->out_ep); 536 if (status) { 537 ERROR(cdev, "config_ep_by_speed FAILED!\n"); 538 goto fail; 539 } 540 status = usb_ep_enable(hidg->out_ep); 541 if (status < 0) { 542 ERROR(cdev, "Enable IN endpoint FAILED!\n"); 543 goto fail; 544 } 545 hidg->out_ep->driver_data = hidg; 546 547 /* 548 * allocate a bunch of read buffers and queue them all at once. 549 */ 550 for (i = 0; i < hidg->qlen && status == 0; i++) { 551 struct usb_request *req = 552 hidg_alloc_ep_req(hidg->out_ep, 553 hidg->report_length); 554 if (req) { 555 req->complete = hidg_set_report_complete; 556 req->context = hidg; 557 status = usb_ep_queue(hidg->out_ep, req, 558 GFP_ATOMIC); 559 if (status) 560 ERROR(cdev, "%s queue req --> %d\n", 561 hidg->out_ep->name, status); 562 } else { 563 usb_ep_disable(hidg->out_ep); 564 status = -ENOMEM; 565 goto fail; 566 } 567 } 568 } 569 570 fail: 571 return status; 572 } 573 574 static const struct file_operations f_hidg_fops = { 575 .owner = THIS_MODULE, 576 .open = f_hidg_open, 577 .release = f_hidg_release, 578 .write = f_hidg_write, 579 .read = f_hidg_read, 580 .poll = f_hidg_poll, 581 .llseek = noop_llseek, 582 }; 583 584 static int hidg_bind(struct usb_configuration *c, struct usb_function *f) 585 { 586 struct usb_ep *ep; 587 struct f_hidg *hidg = func_to_hidg(f); 588 struct usb_string *us; 589 struct device *device; 590 int status; 591 dev_t dev; 592 593 /* maybe allocate device-global string IDs, and patch descriptors */ 594 us = usb_gstrings_attach(c->cdev, ct_func_strings, 595 ARRAY_SIZE(ct_func_string_defs)); 596 if (IS_ERR(us)) 597 return PTR_ERR(us); 598 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id; 599 600 /* allocate instance-specific interface IDs, and patch descriptors */ 601 status = usb_interface_id(c, f); 602 if (status < 0) 603 goto fail; 604 hidg_interface_desc.bInterfaceNumber = status; 605 606 /* allocate instance-specific endpoints */ 607 status = -ENODEV; 608 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc); 609 if (!ep) 610 goto fail; 611 hidg->in_ep = ep; 612 613 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc); 614 if (!ep) 615 goto fail; 616 hidg->out_ep = ep; 617 618 /* preallocate request and buffer */ 619 status = -ENOMEM; 620 hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL); 621 if (!hidg->req) 622 goto fail; 623 624 hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL); 625 if (!hidg->req->buf) 626 goto fail; 627 628 /* set descriptor dynamic values */ 629 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass; 630 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol; 631 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 632 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 633 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 634 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 635 /* 636 * We can use hidg_desc struct here but we should not relay 637 * that its content won't change after returning from this function. 638 */ 639 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT; 640 hidg_desc.desc[0].wDescriptorLength = 641 cpu_to_le16(hidg->report_desc_length); 642 643 hidg_hs_in_ep_desc.bEndpointAddress = 644 hidg_fs_in_ep_desc.bEndpointAddress; 645 hidg_hs_out_ep_desc.bEndpointAddress = 646 hidg_fs_out_ep_desc.bEndpointAddress; 647 648 status = usb_assign_descriptors(f, hidg_fs_descriptors, 649 hidg_hs_descriptors, NULL); 650 if (status) 651 goto fail; 652 653 mutex_init(&hidg->lock); 654 spin_lock_init(&hidg->spinlock); 655 init_waitqueue_head(&hidg->write_queue); 656 init_waitqueue_head(&hidg->read_queue); 657 INIT_LIST_HEAD(&hidg->completed_out_req); 658 659 /* create char device */ 660 cdev_init(&hidg->cdev, &f_hidg_fops); 661 dev = MKDEV(major, hidg->minor); 662 status = cdev_add(&hidg->cdev, dev, 1); 663 if (status) 664 goto fail_free_descs; 665 666 device = device_create(hidg_class, NULL, dev, NULL, 667 "%s%d", "hidg", hidg->minor); 668 if (IS_ERR(device)) { 669 status = PTR_ERR(device); 670 goto del; 671 } 672 673 return 0; 674 del: 675 cdev_del(&hidg->cdev); 676 fail_free_descs: 677 usb_free_all_descriptors(f); 678 fail: 679 ERROR(f->config->cdev, "hidg_bind FAILED\n"); 680 if (hidg->req != NULL) { 681 kfree(hidg->req->buf); 682 if (hidg->in_ep != NULL) 683 usb_ep_free_request(hidg->in_ep, hidg->req); 684 } 685 686 return status; 687 } 688 689 static inline int hidg_get_minor(void) 690 { 691 int ret; 692 693 ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL); 694 if (ret >= HIDG_MINORS) { 695 ida_simple_remove(&hidg_ida, ret); 696 ret = -ENODEV; 697 } 698 699 return ret; 700 } 701 702 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item) 703 { 704 return container_of(to_config_group(item), struct f_hid_opts, 705 func_inst.group); 706 } 707 708 static void hid_attr_release(struct config_item *item) 709 { 710 struct f_hid_opts *opts = to_f_hid_opts(item); 711 712 usb_put_function_instance(&opts->func_inst); 713 } 714 715 static struct configfs_item_operations hidg_item_ops = { 716 .release = hid_attr_release, 717 }; 718 719 #define F_HID_OPT(name, prec, limit) \ 720 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\ 721 { \ 722 struct f_hid_opts *opts = to_f_hid_opts(item); \ 723 int result; \ 724 \ 725 mutex_lock(&opts->lock); \ 726 result = sprintf(page, "%d\n", opts->name); \ 727 mutex_unlock(&opts->lock); \ 728 \ 729 return result; \ 730 } \ 731 \ 732 static ssize_t f_hid_opts_##name##_store(struct config_item *item, \ 733 const char *page, size_t len) \ 734 { \ 735 struct f_hid_opts *opts = to_f_hid_opts(item); \ 736 int ret; \ 737 u##prec num; \ 738 \ 739 mutex_lock(&opts->lock); \ 740 if (opts->refcnt) { \ 741 ret = -EBUSY; \ 742 goto end; \ 743 } \ 744 \ 745 ret = kstrtou##prec(page, 0, &num); \ 746 if (ret) \ 747 goto end; \ 748 \ 749 if (num > limit) { \ 750 ret = -EINVAL; \ 751 goto end; \ 752 } \ 753 opts->name = num; \ 754 ret = len; \ 755 \ 756 end: \ 757 mutex_unlock(&opts->lock); \ 758 return ret; \ 759 } \ 760 \ 761 CONFIGFS_ATTR(f_hid_opts_, name) 762 763 F_HID_OPT(subclass, 8, 255); 764 F_HID_OPT(protocol, 8, 255); 765 F_HID_OPT(report_length, 16, 65535); 766 767 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page) 768 { 769 struct f_hid_opts *opts = to_f_hid_opts(item); 770 int result; 771 772 mutex_lock(&opts->lock); 773 result = opts->report_desc_length; 774 memcpy(page, opts->report_desc, opts->report_desc_length); 775 mutex_unlock(&opts->lock); 776 777 return result; 778 } 779 780 static ssize_t f_hid_opts_report_desc_store(struct config_item *item, 781 const char *page, size_t len) 782 { 783 struct f_hid_opts *opts = to_f_hid_opts(item); 784 int ret = -EBUSY; 785 char *d; 786 787 mutex_lock(&opts->lock); 788 789 if (opts->refcnt) 790 goto end; 791 if (len > PAGE_SIZE) { 792 ret = -ENOSPC; 793 goto end; 794 } 795 d = kmemdup(page, len, GFP_KERNEL); 796 if (!d) { 797 ret = -ENOMEM; 798 goto end; 799 } 800 kfree(opts->report_desc); 801 opts->report_desc = d; 802 opts->report_desc_length = len; 803 opts->report_desc_alloc = true; 804 ret = len; 805 end: 806 mutex_unlock(&opts->lock); 807 return ret; 808 } 809 810 CONFIGFS_ATTR(f_hid_opts_, report_desc); 811 812 static struct configfs_attribute *hid_attrs[] = { 813 &f_hid_opts_attr_subclass, 814 &f_hid_opts_attr_protocol, 815 &f_hid_opts_attr_report_length, 816 &f_hid_opts_attr_report_desc, 817 NULL, 818 }; 819 820 static struct config_item_type hid_func_type = { 821 .ct_item_ops = &hidg_item_ops, 822 .ct_attrs = hid_attrs, 823 .ct_owner = THIS_MODULE, 824 }; 825 826 static inline void hidg_put_minor(int minor) 827 { 828 ida_simple_remove(&hidg_ida, minor); 829 } 830 831 static void hidg_free_inst(struct usb_function_instance *f) 832 { 833 struct f_hid_opts *opts; 834 835 opts = container_of(f, struct f_hid_opts, func_inst); 836 837 mutex_lock(&hidg_ida_lock); 838 839 hidg_put_minor(opts->minor); 840 if (idr_is_empty(&hidg_ida.idr)) 841 ghid_cleanup(); 842 843 mutex_unlock(&hidg_ida_lock); 844 845 if (opts->report_desc_alloc) 846 kfree(opts->report_desc); 847 848 kfree(opts); 849 } 850 851 static struct usb_function_instance *hidg_alloc_inst(void) 852 { 853 struct f_hid_opts *opts; 854 struct usb_function_instance *ret; 855 int status = 0; 856 857 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 858 if (!opts) 859 return ERR_PTR(-ENOMEM); 860 mutex_init(&opts->lock); 861 opts->func_inst.free_func_inst = hidg_free_inst; 862 ret = &opts->func_inst; 863 864 mutex_lock(&hidg_ida_lock); 865 866 if (idr_is_empty(&hidg_ida.idr)) { 867 status = ghid_setup(NULL, HIDG_MINORS); 868 if (status) { 869 ret = ERR_PTR(status); 870 kfree(opts); 871 goto unlock; 872 } 873 } 874 875 opts->minor = hidg_get_minor(); 876 if (opts->minor < 0) { 877 ret = ERR_PTR(opts->minor); 878 kfree(opts); 879 if (idr_is_empty(&hidg_ida.idr)) 880 ghid_cleanup(); 881 goto unlock; 882 } 883 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type); 884 885 unlock: 886 mutex_unlock(&hidg_ida_lock); 887 return ret; 888 } 889 890 static void hidg_free(struct usb_function *f) 891 { 892 struct f_hidg *hidg; 893 struct f_hid_opts *opts; 894 895 hidg = func_to_hidg(f); 896 opts = container_of(f->fi, struct f_hid_opts, func_inst); 897 kfree(hidg->report_desc); 898 kfree(hidg); 899 mutex_lock(&opts->lock); 900 --opts->refcnt; 901 mutex_unlock(&opts->lock); 902 } 903 904 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) 905 { 906 struct f_hidg *hidg = func_to_hidg(f); 907 908 device_destroy(hidg_class, MKDEV(major, hidg->minor)); 909 cdev_del(&hidg->cdev); 910 911 /* disable/free request and end point */ 912 usb_ep_disable(hidg->in_ep); 913 kfree(hidg->req->buf); 914 usb_ep_free_request(hidg->in_ep, hidg->req); 915 916 usb_free_all_descriptors(f); 917 } 918 919 static struct usb_function *hidg_alloc(struct usb_function_instance *fi) 920 { 921 struct f_hidg *hidg; 922 struct f_hid_opts *opts; 923 924 /* allocate and initialize one new instance */ 925 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL); 926 if (!hidg) 927 return ERR_PTR(-ENOMEM); 928 929 opts = container_of(fi, struct f_hid_opts, func_inst); 930 931 mutex_lock(&opts->lock); 932 ++opts->refcnt; 933 934 hidg->minor = opts->minor; 935 hidg->bInterfaceSubClass = opts->subclass; 936 hidg->bInterfaceProtocol = opts->protocol; 937 hidg->report_length = opts->report_length; 938 hidg->report_desc_length = opts->report_desc_length; 939 if (opts->report_desc) { 940 hidg->report_desc = kmemdup(opts->report_desc, 941 opts->report_desc_length, 942 GFP_KERNEL); 943 if (!hidg->report_desc) { 944 kfree(hidg); 945 mutex_unlock(&opts->lock); 946 return ERR_PTR(-ENOMEM); 947 } 948 } 949 950 mutex_unlock(&opts->lock); 951 952 hidg->func.name = "hid"; 953 hidg->func.bind = hidg_bind; 954 hidg->func.unbind = hidg_unbind; 955 hidg->func.set_alt = hidg_set_alt; 956 hidg->func.disable = hidg_disable; 957 hidg->func.setup = hidg_setup; 958 hidg->func.free_func = hidg_free; 959 960 /* this could me made configurable at some point */ 961 hidg->qlen = 4; 962 963 return &hidg->func; 964 } 965 966 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc); 967 MODULE_LICENSE("GPL"); 968 MODULE_AUTHOR("Fabien Chouteau"); 969 970 int ghid_setup(struct usb_gadget *g, int count) 971 { 972 int status; 973 dev_t dev; 974 975 hidg_class = class_create(THIS_MODULE, "hidg"); 976 if (IS_ERR(hidg_class)) { 977 status = PTR_ERR(hidg_class); 978 hidg_class = NULL; 979 return status; 980 } 981 982 status = alloc_chrdev_region(&dev, 0, count, "hidg"); 983 if (status) { 984 class_destroy(hidg_class); 985 hidg_class = NULL; 986 return status; 987 } 988 989 major = MAJOR(dev); 990 minors = count; 991 992 return 0; 993 } 994 995 void ghid_cleanup(void) 996 { 997 if (major) { 998 unregister_chrdev_region(MKDEV(major, 0), minors); 999 major = minors = 0; 1000 } 1001 1002 class_destroy(hidg_class); 1003 hidg_class = NULL; 1004 } 1005