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, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x " 403 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value); 404 405 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { 406 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 407 | HID_REQ_GET_REPORT): 408 VDBG(cdev, "get_report\n"); 409 410 /* send an empty report */ 411 length = min_t(unsigned, length, hidg->report_length); 412 memset(req->buf, 0x0, length); 413 414 goto respond; 415 break; 416 417 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 418 | HID_REQ_GET_PROTOCOL): 419 VDBG(cdev, "get_protocol\n"); 420 goto stall; 421 break; 422 423 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 424 | HID_REQ_SET_REPORT): 425 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength); 426 goto stall; 427 break; 428 429 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 430 | HID_REQ_SET_PROTOCOL): 431 VDBG(cdev, "set_protocol\n"); 432 goto stall; 433 break; 434 435 case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8 436 | USB_REQ_GET_DESCRIPTOR): 437 switch (value >> 8) { 438 case HID_DT_HID: 439 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n"); 440 length = min_t(unsigned short, length, 441 hidg_desc.bLength); 442 memcpy(req->buf, &hidg_desc, length); 443 goto respond; 444 break; 445 case HID_DT_REPORT: 446 VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n"); 447 length = min_t(unsigned short, length, 448 hidg->report_desc_length); 449 memcpy(req->buf, hidg->report_desc, length); 450 goto respond; 451 break; 452 453 default: 454 VDBG(cdev, "Unknown descriptor request 0x%x\n", 455 value >> 8); 456 goto stall; 457 break; 458 } 459 break; 460 461 default: 462 VDBG(cdev, "Unknown request 0x%x\n", 463 ctrl->bRequest); 464 goto stall; 465 break; 466 } 467 468 stall: 469 return -EOPNOTSUPP; 470 471 respond: 472 req->zero = 0; 473 req->length = length; 474 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); 475 if (status < 0) 476 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value); 477 return status; 478 } 479 480 static void hidg_disable(struct usb_function *f) 481 { 482 struct f_hidg *hidg = func_to_hidg(f); 483 struct f_hidg_req_list *list, *next; 484 485 usb_ep_disable(hidg->in_ep); 486 hidg->in_ep->driver_data = NULL; 487 488 usb_ep_disable(hidg->out_ep); 489 hidg->out_ep->driver_data = NULL; 490 491 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) { 492 list_del(&list->list); 493 kfree(list); 494 } 495 } 496 497 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt) 498 { 499 struct usb_composite_dev *cdev = f->config->cdev; 500 struct f_hidg *hidg = func_to_hidg(f); 501 int i, status = 0; 502 503 VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt); 504 505 if (hidg->in_ep != NULL) { 506 /* restart endpoint */ 507 if (hidg->in_ep->driver_data != NULL) 508 usb_ep_disable(hidg->in_ep); 509 510 status = config_ep_by_speed(f->config->cdev->gadget, f, 511 hidg->in_ep); 512 if (status) { 513 ERROR(cdev, "config_ep_by_speed FAILED!\n"); 514 goto fail; 515 } 516 status = usb_ep_enable(hidg->in_ep); 517 if (status < 0) { 518 ERROR(cdev, "Enable IN endpoint FAILED!\n"); 519 goto fail; 520 } 521 hidg->in_ep->driver_data = hidg; 522 } 523 524 525 if (hidg->out_ep != NULL) { 526 /* restart endpoint */ 527 if (hidg->out_ep->driver_data != NULL) 528 usb_ep_disable(hidg->out_ep); 529 530 status = config_ep_by_speed(f->config->cdev->gadget, f, 531 hidg->out_ep); 532 if (status) { 533 ERROR(cdev, "config_ep_by_speed FAILED!\n"); 534 goto fail; 535 } 536 status = usb_ep_enable(hidg->out_ep); 537 if (status < 0) { 538 ERROR(cdev, "Enable IN endpoint FAILED!\n"); 539 goto fail; 540 } 541 hidg->out_ep->driver_data = hidg; 542 543 /* 544 * allocate a bunch of read buffers and queue them all at once. 545 */ 546 for (i = 0; i < hidg->qlen && status == 0; i++) { 547 struct usb_request *req = 548 hidg_alloc_ep_req(hidg->out_ep, 549 hidg->report_length); 550 if (req) { 551 req->complete = hidg_set_report_complete; 552 req->context = hidg; 553 status = usb_ep_queue(hidg->out_ep, req, 554 GFP_ATOMIC); 555 if (status) 556 ERROR(cdev, "%s queue req --> %d\n", 557 hidg->out_ep->name, status); 558 } else { 559 usb_ep_disable(hidg->out_ep); 560 hidg->out_ep->driver_data = NULL; 561 status = -ENOMEM; 562 goto fail; 563 } 564 } 565 } 566 567 fail: 568 return status; 569 } 570 571 const struct file_operations f_hidg_fops = { 572 .owner = THIS_MODULE, 573 .open = f_hidg_open, 574 .release = f_hidg_release, 575 .write = f_hidg_write, 576 .read = f_hidg_read, 577 .poll = f_hidg_poll, 578 .llseek = noop_llseek, 579 }; 580 581 static int hidg_bind(struct usb_configuration *c, struct usb_function *f) 582 { 583 struct usb_ep *ep; 584 struct f_hidg *hidg = func_to_hidg(f); 585 struct usb_string *us; 586 struct device *device; 587 int status; 588 dev_t dev; 589 590 /* maybe allocate device-global string IDs, and patch descriptors */ 591 us = usb_gstrings_attach(c->cdev, ct_func_strings, 592 ARRAY_SIZE(ct_func_string_defs)); 593 if (IS_ERR(us)) 594 return PTR_ERR(us); 595 hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id; 596 597 /* allocate instance-specific interface IDs, and patch descriptors */ 598 status = usb_interface_id(c, f); 599 if (status < 0) 600 goto fail; 601 hidg_interface_desc.bInterfaceNumber = status; 602 603 /* allocate instance-specific endpoints */ 604 status = -ENODEV; 605 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc); 606 if (!ep) 607 goto fail; 608 ep->driver_data = c->cdev; /* claim */ 609 hidg->in_ep = ep; 610 611 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc); 612 if (!ep) 613 goto fail; 614 ep->driver_data = c->cdev; /* claim */ 615 hidg->out_ep = ep; 616 617 /* preallocate request and buffer */ 618 status = -ENOMEM; 619 hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL); 620 if (!hidg->req) 621 goto fail; 622 623 hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL); 624 if (!hidg->req->buf) 625 goto fail; 626 627 /* set descriptor dynamic values */ 628 hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass; 629 hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol; 630 hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 631 hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 632 hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 633 hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); 634 hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT; 635 hidg_desc.desc[0].wDescriptorLength = 636 cpu_to_le16(hidg->report_desc_length); 637 638 hidg_hs_in_ep_desc.bEndpointAddress = 639 hidg_fs_in_ep_desc.bEndpointAddress; 640 hidg_hs_out_ep_desc.bEndpointAddress = 641 hidg_fs_out_ep_desc.bEndpointAddress; 642 643 status = usb_assign_descriptors(f, hidg_fs_descriptors, 644 hidg_hs_descriptors, NULL); 645 if (status) 646 goto fail; 647 648 mutex_init(&hidg->lock); 649 spin_lock_init(&hidg->spinlock); 650 init_waitqueue_head(&hidg->write_queue); 651 init_waitqueue_head(&hidg->read_queue); 652 INIT_LIST_HEAD(&hidg->completed_out_req); 653 654 /* create char device */ 655 cdev_init(&hidg->cdev, &f_hidg_fops); 656 dev = MKDEV(major, hidg->minor); 657 status = cdev_add(&hidg->cdev, dev, 1); 658 if (status) 659 goto fail_free_descs; 660 661 device = device_create(hidg_class, NULL, dev, NULL, 662 "%s%d", "hidg", hidg->minor); 663 if (IS_ERR(device)) { 664 status = PTR_ERR(device); 665 goto del; 666 } 667 668 return 0; 669 del: 670 cdev_del(&hidg->cdev); 671 fail_free_descs: 672 usb_free_all_descriptors(f); 673 fail: 674 ERROR(f->config->cdev, "hidg_bind FAILED\n"); 675 if (hidg->req != NULL) { 676 kfree(hidg->req->buf); 677 if (hidg->in_ep != NULL) 678 usb_ep_free_request(hidg->in_ep, hidg->req); 679 } 680 681 return status; 682 } 683 684 static inline int hidg_get_minor(void) 685 { 686 int ret; 687 688 ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL); 689 690 return ret; 691 } 692 693 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item) 694 { 695 return container_of(to_config_group(item), struct f_hid_opts, 696 func_inst.group); 697 } 698 699 CONFIGFS_ATTR_STRUCT(f_hid_opts); 700 CONFIGFS_ATTR_OPS(f_hid_opts); 701 702 static void hid_attr_release(struct config_item *item) 703 { 704 struct f_hid_opts *opts = to_f_hid_opts(item); 705 706 usb_put_function_instance(&opts->func_inst); 707 } 708 709 static struct configfs_item_operations hidg_item_ops = { 710 .release = hid_attr_release, 711 .show_attribute = f_hid_opts_attr_show, 712 .store_attribute = f_hid_opts_attr_store, 713 }; 714 715 #define F_HID_OPT(name, prec, limit) \ 716 static ssize_t f_hid_opts_##name##_show(struct f_hid_opts *opts, char *page)\ 717 { \ 718 int result; \ 719 \ 720 mutex_lock(&opts->lock); \ 721 result = sprintf(page, "%d\n", opts->name); \ 722 mutex_unlock(&opts->lock); \ 723 \ 724 return result; \ 725 } \ 726 \ 727 static ssize_t f_hid_opts_##name##_store(struct f_hid_opts *opts, \ 728 const char *page, size_t len) \ 729 { \ 730 int ret; \ 731 u##prec num; \ 732 \ 733 mutex_lock(&opts->lock); \ 734 if (opts->refcnt) { \ 735 ret = -EBUSY; \ 736 goto end; \ 737 } \ 738 \ 739 ret = kstrtou##prec(page, 0, &num); \ 740 if (ret) \ 741 goto end; \ 742 \ 743 if (num > limit) { \ 744 ret = -EINVAL; \ 745 goto end; \ 746 } \ 747 opts->name = num; \ 748 ret = len; \ 749 \ 750 end: \ 751 mutex_unlock(&opts->lock); \ 752 return ret; \ 753 } \ 754 \ 755 static struct f_hid_opts_attribute f_hid_opts_##name = \ 756 __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_hid_opts_##name##_show,\ 757 f_hid_opts_##name##_store) 758 759 F_HID_OPT(subclass, 8, 255); 760 F_HID_OPT(protocol, 8, 255); 761 F_HID_OPT(report_length, 16, 65536); 762 763 static ssize_t f_hid_opts_report_desc_show(struct f_hid_opts *opts, char *page) 764 { 765 int result; 766 767 mutex_lock(&opts->lock); 768 result = opts->report_desc_length; 769 memcpy(page, opts->report_desc, opts->report_desc_length); 770 mutex_unlock(&opts->lock); 771 772 return result; 773 } 774 775 static ssize_t f_hid_opts_report_desc_store(struct f_hid_opts *opts, 776 const char *page, size_t len) 777 { 778 int ret = -EBUSY; 779 char *d; 780 781 mutex_lock(&opts->lock); 782 783 if (opts->refcnt) 784 goto end; 785 if (len > PAGE_SIZE) { 786 ret = -ENOSPC; 787 goto end; 788 } 789 d = kmemdup(page, len, GFP_KERNEL); 790 if (!d) { 791 ret = -ENOMEM; 792 goto end; 793 } 794 kfree(opts->report_desc); 795 opts->report_desc = d; 796 opts->report_desc_length = len; 797 opts->report_desc_alloc = true; 798 ret = len; 799 end: 800 mutex_unlock(&opts->lock); 801 return ret; 802 } 803 804 static struct f_hid_opts_attribute f_hid_opts_report_desc = 805 __CONFIGFS_ATTR(report_desc, S_IRUGO | S_IWUSR, 806 f_hid_opts_report_desc_show, 807 f_hid_opts_report_desc_store); 808 809 static struct configfs_attribute *hid_attrs[] = { 810 &f_hid_opts_subclass.attr, 811 &f_hid_opts_protocol.attr, 812 &f_hid_opts_report_length.attr, 813 &f_hid_opts_report_desc.attr, 814 NULL, 815 }; 816 817 static struct config_item_type hid_func_type = { 818 .ct_item_ops = &hidg_item_ops, 819 .ct_attrs = hid_attrs, 820 .ct_owner = THIS_MODULE, 821 }; 822 823 static inline void hidg_put_minor(int minor) 824 { 825 ida_simple_remove(&hidg_ida, minor); 826 } 827 828 static void hidg_free_inst(struct usb_function_instance *f) 829 { 830 struct f_hid_opts *opts; 831 832 opts = container_of(f, struct f_hid_opts, func_inst); 833 834 mutex_lock(&hidg_ida_lock); 835 836 hidg_put_minor(opts->minor); 837 if (idr_is_empty(&hidg_ida.idr)) 838 ghid_cleanup(); 839 840 mutex_unlock(&hidg_ida_lock); 841 842 if (opts->report_desc_alloc) 843 kfree(opts->report_desc); 844 845 kfree(opts); 846 } 847 848 static struct usb_function_instance *hidg_alloc_inst(void) 849 { 850 struct f_hid_opts *opts; 851 struct usb_function_instance *ret; 852 int status = 0; 853 854 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 855 if (!opts) 856 return ERR_PTR(-ENOMEM); 857 mutex_init(&opts->lock); 858 opts->func_inst.free_func_inst = hidg_free_inst; 859 ret = &opts->func_inst; 860 861 mutex_lock(&hidg_ida_lock); 862 863 if (idr_is_empty(&hidg_ida.idr)) { 864 status = ghid_setup(NULL, HIDG_MINORS); 865 if (status) { 866 ret = ERR_PTR(status); 867 kfree(opts); 868 goto unlock; 869 } 870 } 871 872 opts->minor = hidg_get_minor(); 873 if (opts->minor < 0) { 874 ret = ERR_PTR(opts->minor); 875 kfree(opts); 876 if (idr_is_empty(&hidg_ida.idr)) 877 ghid_cleanup(); 878 goto unlock; 879 } 880 config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type); 881 882 unlock: 883 mutex_unlock(&hidg_ida_lock); 884 return ret; 885 } 886 887 static void hidg_free(struct usb_function *f) 888 { 889 struct f_hidg *hidg; 890 struct f_hid_opts *opts; 891 892 hidg = func_to_hidg(f); 893 opts = container_of(f->fi, struct f_hid_opts, func_inst); 894 kfree(hidg->report_desc); 895 kfree(hidg); 896 mutex_lock(&opts->lock); 897 --opts->refcnt; 898 mutex_unlock(&opts->lock); 899 } 900 901 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) 902 { 903 struct f_hidg *hidg = func_to_hidg(f); 904 905 device_destroy(hidg_class, MKDEV(major, hidg->minor)); 906 cdev_del(&hidg->cdev); 907 908 /* disable/free request and end point */ 909 usb_ep_disable(hidg->in_ep); 910 usb_ep_dequeue(hidg->in_ep, hidg->req); 911 kfree(hidg->req->buf); 912 usb_ep_free_request(hidg->in_ep, hidg->req); 913 914 usb_free_all_descriptors(f); 915 } 916 917 static struct usb_function *hidg_alloc(struct usb_function_instance *fi) 918 { 919 struct f_hidg *hidg; 920 struct f_hid_opts *opts; 921 922 /* allocate and initialize one new instance */ 923 hidg = kzalloc(sizeof(*hidg), GFP_KERNEL); 924 if (!hidg) 925 return ERR_PTR(-ENOMEM); 926 927 opts = container_of(fi, struct f_hid_opts, func_inst); 928 929 mutex_lock(&opts->lock); 930 ++opts->refcnt; 931 932 hidg->minor = opts->minor; 933 hidg->bInterfaceSubClass = opts->subclass; 934 hidg->bInterfaceProtocol = opts->protocol; 935 hidg->report_length = opts->report_length; 936 hidg->report_desc_length = opts->report_desc_length; 937 if (opts->report_desc) { 938 hidg->report_desc = kmemdup(opts->report_desc, 939 opts->report_desc_length, 940 GFP_KERNEL); 941 if (!hidg->report_desc) { 942 kfree(hidg); 943 mutex_unlock(&opts->lock); 944 return ERR_PTR(-ENOMEM); 945 } 946 } 947 948 mutex_unlock(&opts->lock); 949 950 hidg->func.name = "hid"; 951 hidg->func.bind = hidg_bind; 952 hidg->func.unbind = hidg_unbind; 953 hidg->func.set_alt = hidg_set_alt; 954 hidg->func.disable = hidg_disable; 955 hidg->func.setup = hidg_setup; 956 hidg->func.free_func = hidg_free; 957 958 /* this could me made configurable at some point */ 959 hidg->qlen = 4; 960 961 return &hidg->func; 962 } 963 964 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc); 965 MODULE_LICENSE("GPL"); 966 MODULE_AUTHOR("Fabien Chouteau"); 967 968 int ghid_setup(struct usb_gadget *g, int count) 969 { 970 int status; 971 dev_t dev; 972 973 hidg_class = class_create(THIS_MODULE, "hidg"); 974 if (IS_ERR(hidg_class)) { 975 status = PTR_ERR(hidg_class); 976 hidg_class = NULL; 977 return status; 978 } 979 980 status = alloc_chrdev_region(&dev, 0, count, "hidg"); 981 if (status) { 982 class_destroy(hidg_class); 983 hidg_class = NULL; 984 return status; 985 } 986 987 major = MAJOR(dev); 988 minors = count; 989 990 return 0; 991 } 992 993 void ghid_cleanup(void) 994 { 995 if (major) { 996 unregister_chrdev_region(MKDEV(major, 0), minors); 997 major = minors = 0; 998 } 999 1000 class_destroy(hidg_class); 1001 hidg_class = NULL; 1002 } 1003