drivers/usb/gadget/function/f_eem.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_eem.c -- USB CDC Ethernet (EEM) link function driver
   4  *
   5  * Copyright (C) 2003-2005,2008 David Brownell
   6  * Copyright (C) 2008 Nokia Corporation
   7  * Copyright (C) 2009 EF Johnson Technologies
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/device.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/crc32.h>
  15 #include <linux/slab.h>
  16
  17 #include "u_ether.h"
  18 #include "u_ether_configfs.h"
  19 #include "u_eem.h"
  20
  21 #define EEM_HLEN 2
  22
  23 /*
  24  * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
  25  * Ethernet link.
  26  */
  27
  28 struct f_eem {
  29         struct gether                   port;
  30         u8                              ctrl_id;
  31 };
  32
  33 struct in_context {
  34         struct sk_buff  *skb;
  35         struct usb_ep   *ep;
  36 };
  37
  38 static inline struct f_eem *func_to_eem(struct usb_function *f)
  39 {
  40         return container_of(f, struct f_eem, port.func);
  41 }
  42
  43 /*-------------------------------------------------------------------------*/
  44
  45 /* interface descriptor: */
  46
  47 static struct usb_interface_descriptor eem_intf = {
  48         .bLength =              sizeof eem_intf,
  49         .bDescriptorType =      USB_DT_INTERFACE,
  50
  51         /* .bInterfaceNumber = DYNAMIC */
  52         .bNumEndpoints =        2,
  53         .bInterfaceClass =      USB_CLASS_COMM,
  54         .bInterfaceSubClass =   USB_CDC_SUBCLASS_EEM,
  55         .bInterfaceProtocol =   USB_CDC_PROTO_EEM,
  56         /* .iInterface = DYNAMIC */
  57 };
  58
  59 /* full speed support: */
  60
  61 static struct usb_endpoint_descriptor eem_fs_in_desc = {
  62         .bLength =              USB_DT_ENDPOINT_SIZE,
  63         .bDescriptorType =      USB_DT_ENDPOINT,
  64
  65         .bEndpointAddress =     USB_DIR_IN,
  66         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
  67 };
  68
  69 static struct usb_endpoint_descriptor eem_fs_out_desc = {
  70         .bLength =              USB_DT_ENDPOINT_SIZE,
  71         .bDescriptorType =      USB_DT_ENDPOINT,
  72
  73         .bEndpointAddress =     USB_DIR_OUT,
  74         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
  75 };
  76
  77 static struct usb_descriptor_header *eem_fs_function[] = {
  78         /* CDC EEM control descriptors */
  79         (struct usb_descriptor_header *) &eem_intf,
  80         (struct usb_descriptor_header *) &eem_fs_in_desc,
  81         (struct usb_descriptor_header *) &eem_fs_out_desc,
  82         NULL,
  83 };
  84
  85 /* high speed support: */
  86
  87 static struct usb_endpoint_descriptor eem_hs_in_desc = {
  88         .bLength =              USB_DT_ENDPOINT_SIZE,
  89         .bDescriptorType =      USB_DT_ENDPOINT,
  90
  91         .bEndpointAddress =     USB_DIR_IN,
  92         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
  93         .wMaxPacketSize =       cpu_to_le16(512),
  94 };
  95
  96 static struct usb_endpoint_descriptor eem_hs_out_desc = {
  97         .bLength =              USB_DT_ENDPOINT_SIZE,
  98         .bDescriptorType =      USB_DT_ENDPOINT,
  99
 100         .bEndpointAddress =     USB_DIR_OUT,
 101         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 102         .wMaxPacketSize =       cpu_to_le16(512),
 103 };
 104
 105 static struct usb_descriptor_header *eem_hs_function[] = {
 106         /* CDC EEM control descriptors */
 107         (struct usb_descriptor_header *) &eem_intf,
 108         (struct usb_descriptor_header *) &eem_hs_in_desc,
 109         (struct usb_descriptor_header *) &eem_hs_out_desc,
 110         NULL,
 111 };
 112
 113 /* super speed support: */
 114
 115 static struct usb_endpoint_descriptor eem_ss_in_desc = {
 116         .bLength =              USB_DT_ENDPOINT_SIZE,
 117         .bDescriptorType =      USB_DT_ENDPOINT,
 118
 119         .bEndpointAddress =     USB_DIR_IN,
 120         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 121         .wMaxPacketSize =       cpu_to_le16(1024),
 122 };
 123
 124 static struct usb_endpoint_descriptor eem_ss_out_desc = {
 125         .bLength =              USB_DT_ENDPOINT_SIZE,
 126         .bDescriptorType =      USB_DT_ENDPOINT,
 127
 128         .bEndpointAddress =     USB_DIR_OUT,
 129         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 130         .wMaxPacketSize =       cpu_to_le16(1024),
 131 };
 132
 133 static struct usb_ss_ep_comp_descriptor eem_ss_bulk_comp_desc = {
 134         .bLength =              sizeof eem_ss_bulk_comp_desc,
 135         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 136
 137         /* the following 2 values can be tweaked if necessary */
 138         /* .bMaxBurst =         0, */
 139         /* .bmAttributes =      0, */
 140 };
 141
 142 static struct usb_descriptor_header *eem_ss_function[] = {
 143         /* CDC EEM control descriptors */
 144         (struct usb_descriptor_header *) &eem_intf,
 145         (struct usb_descriptor_header *) &eem_ss_in_desc,
 146         (struct usb_descriptor_header *) &eem_ss_bulk_comp_desc,
 147         (struct usb_descriptor_header *) &eem_ss_out_desc,
 148         (struct usb_descriptor_header *) &eem_ss_bulk_comp_desc,
 149         NULL,
 150 };
 151
 152 /* string descriptors: */
 153
 154 static struct usb_string eem_string_defs[] = {
 155         [0].s = "CDC Ethernet Emulation Model (EEM)",
 156         {  } /* end of list */
 157 };
 158
 159 static struct usb_gadget_strings eem_string_table = {
 160         .language =             0x0409, /* en-us */
 161         .strings =              eem_string_defs,
 162 };
 163
 164 static struct usb_gadget_strings *eem_strings[] = {
 165         &eem_string_table,
 166         NULL,
 167 };
 168
 169 /*-------------------------------------------------------------------------*/
 170
 171 static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 172 {
 173         struct usb_composite_dev *cdev = f->config->cdev;
 174         int                     value = -EOPNOTSUPP;
 175         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 176         u16                     w_value = le16_to_cpu(ctrl->wValue);
 177         u16                     w_length = le16_to_cpu(ctrl->wLength);
 178
 179         DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 180                 ctrl->bRequestType, ctrl->bRequest,
 181                 w_value, w_index, w_length);
 182
 183         /* device either stalls (value < 0) or reports success */
 184         return value;
 185 }
 186
 187
 188 static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 189 {
 190         struct f_eem            *eem = func_to_eem(f);
 191         struct usb_composite_dev *cdev = f->config->cdev;
 192         struct net_device       *net;
 193
 194         /* we know alt == 0, so this is an activation or a reset */
 195         if (alt != 0)
 196                 goto fail;
 197
 198         if (intf == eem->ctrl_id) {
 199                 DBG(cdev, "reset eem\n");
 200                 gether_disconnect(&eem->port);
 201
 202                 if (!eem->port.in_ep->desc || !eem->port.out_ep->desc) {
 203                         DBG(cdev, "init eem\n");
 204                         if (config_ep_by_speed(cdev->gadget, f,
 205                                                eem->port.in_ep) ||
 206                             config_ep_by_speed(cdev->gadget, f,
 207                                                eem->port.out_ep)) {
 208                                 eem->port.in_ep->desc = NULL;
 209                                 eem->port.out_ep->desc = NULL;
 210                                 goto fail;
 211                         }
 212                 }
 213
 214                 /* zlps should not occur because zero-length EEM packets
 215                  * will be inserted in those cases where they would occur
 216                  */
 217                 eem->port.is_zlp_ok = 1;
 218                 eem->port.cdc_filter = DEFAULT_FILTER;
 219                 DBG(cdev, "activate eem\n");
 220                 net = gether_connect(&eem->port);
 221                 if (IS_ERR(net))
 222                         return PTR_ERR(net);
 223         } else
 224                 goto fail;
 225
 226         return 0;
 227 fail:
 228         return -EINVAL;
 229 }
 230
 231 static void eem_disable(struct usb_function *f)
 232 {
 233         struct f_eem            *eem = func_to_eem(f);
 234         struct usb_composite_dev *cdev = f->config->cdev;
 235
 236         DBG(cdev, "eem deactivated\n");
 237
 238         if (eem->port.in_ep->enabled)
 239                 gether_disconnect(&eem->port);
 240 }
 241
 242 /*-------------------------------------------------------------------------*/
 243
 244 /* EEM function driver setup/binding */
 245
 246 static int eem_bind(struct usb_configuration *c, struct usb_function *f)
 247 {
 248         struct usb_composite_dev *cdev = c->cdev;
 249         struct f_eem            *eem = func_to_eem(f);
 250         struct usb_string       *us;
 251         int                     status;
 252         struct usb_ep           *ep;
 253
 254         struct f_eem_opts       *eem_opts;
 255
 256         eem_opts = container_of(f->fi, struct f_eem_opts, func_inst);
 257         /*
 258          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 259          * configurations are bound in sequence with list_for_each_entry,
 260          * in each configuration its functions are bound in sequence
 261          * with list_for_each_entry, so we assume no race condition
 262          * with regard to eem_opts->bound access
 263          */
 264         if (!eem_opts->bound) {
 265                 mutex_lock(&eem_opts->lock);
 266                 gether_set_gadget(eem_opts->net, cdev->gadget);
 267                 status = gether_register_netdev(eem_opts->net);
 268                 mutex_unlock(&eem_opts->lock);
 269                 if (status)
 270                         return status;
 271                 eem_opts->bound = true;
 272         }
 273
 274         us = usb_gstrings_attach(cdev, eem_strings,
 275                                  ARRAY_SIZE(eem_string_defs));
 276         if (IS_ERR(us))
 277                 return PTR_ERR(us);
 278         eem_intf.iInterface = us[0].id;
 279
 280         /* allocate instance-specific interface IDs */
 281         status = usb_interface_id(c, f);
 282         if (status < 0)
 283                 goto fail;
 284         eem->ctrl_id = status;
 285         eem_intf.bInterfaceNumber = status;
 286
 287         status = -ENODEV;
 288
 289         /* allocate instance-specific endpoints */
 290         ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
 291         if (!ep)
 292                 goto fail;
 293         eem->port.in_ep = ep;
 294
 295         ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
 296         if (!ep)
 297                 goto fail;
 298         eem->port.out_ep = ep;
 299
 300         status = -ENOMEM;
 301
 302         /* support all relevant hardware speeds... we expect that when
 303          * hardware is dual speed, all bulk-capable endpoints work at
 304          * both speeds
 305          */
 306         eem_hs_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
 307         eem_hs_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
 308
 309         eem_ss_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress;
 310         eem_ss_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress;
 311
 312         status = usb_assign_descriptors(f, eem_fs_function, eem_hs_function,
 313                         eem_ss_function, eem_ss_function);
 314         if (status)
 315                 goto fail;
 316
 317         DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
 318                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 319                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 320                         eem->port.in_ep->name, eem->port.out_ep->name);
 321         return 0;
 322
 323 fail:
 324         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 325
 326         return status;
 327 }
 328
 329 static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
 330 {
 331         struct in_context *ctx = req->context;
 332
 333         dev_kfree_skb_any(ctx->skb);
 334         kfree(req->buf);
 335         usb_ep_free_request(ctx->ep, req);
 336         kfree(ctx);
 337 }
 338
 339 /*
 340  * Add the EEM header and ethernet checksum.
 341  * We currently do not attempt to put multiple ethernet frames
 342  * into a single USB transfer
 343  */
 344 static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
 345 {
 346         struct sk_buff  *skb2 = NULL;
 347         struct usb_ep   *in = port->in_ep;
 348         int             headroom, tailroom, padlen = 0;
 349         u16             len;
 350
 351         if (!skb)
 352                 return NULL;
 353
 354         len = skb->len;
 355         headroom = skb_headroom(skb);
 356         tailroom = skb_tailroom(skb);
 357
 358         /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
 359          * stick two bytes of zero-length EEM packet on the end.
 360          */
 361         if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
 362                 padlen += 2;
 363
 364         if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
 365                         (headroom >= EEM_HLEN) && !skb_cloned(skb))
 366                 goto done;
 367
 368         skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
 369         dev_kfree_skb_any(skb);
 370         skb = skb2;
 371         if (!skb)
 372                 return skb;
 373
 374 done:
 375         /* use the "no CRC" option */
 376         put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
 377
 378         /* EEM packet header format:
 379          * b0..13:      length of ethernet frame
 380          * b14:         bmCRC (0 == sentinel CRC)
 381          * b15:         bmType (0 == data)
 382          */
 383         len = skb->len;
 384         put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));
 385
 386         /* add a zero-length EEM packet, if needed */
 387         if (padlen)
 388                 put_unaligned_le16(0, skb_put(skb, 2));
 389
 390         return skb;
 391 }
 392
 393 /*
 394  * Remove the EEM header.  Note that there can be many EEM packets in a single
 395  * USB transfer, so we need to break them out and handle them independently.
 396  */
 397 static int eem_unwrap(struct gether *port,
 398                         struct sk_buff *skb,
 399                         struct sk_buff_head *list)
 400 {
 401         struct usb_composite_dev        *cdev = port->func.config->cdev;
 402         int                             status = 0;
 403
 404         do {
 405                 struct sk_buff  *skb2;
 406                 u16             header;
 407                 u16             len = 0;
 408
 409                 if (skb->len < EEM_HLEN) {
 410                         status = -EINVAL;
 411                         DBG(cdev, "invalid EEM header\n");
 412                         goto error;
 413                 }
 414
 415                 /* remove the EEM header */
 416                 header = get_unaligned_le16(skb->data);
 417                 skb_pull(skb, EEM_HLEN);
 418
 419                 /* EEM packet header format:
 420                  * b0..14:      EEM type dependent (data or command)
 421                  * b15:         bmType (0 == data, 1 == command)
 422                  */
 423                 if (header & BIT(15)) {
 424                         struct usb_request      *req;
 425                         struct in_context       *ctx;
 426                         struct usb_ep           *ep;
 427                         u16                     bmEEMCmd;
 428
 429                         /* EEM command packet format:
 430                          * b0..10:      bmEEMCmdParam
 431                          * b11..13:     bmEEMCmd
 432                          * b14:         reserved (must be zero)
 433                          * b15:         bmType (1 == command)
 434                          */
 435                         if (header & BIT(14))
 436                                 continue;
 437
 438                         bmEEMCmd = (header >> 11) & 0x7;
 439                         switch (bmEEMCmd) {
 440                         case 0: /* echo */
 441                                 len = header & 0x7FF;
 442                                 if (skb->len < len) {
 443                                         status = -EOVERFLOW;
 444                                         goto error;
 445                                 }
 446
 447                                 skb2 = skb_clone(skb, GFP_ATOMIC);
 448                                 if (unlikely(!skb2)) {
 449                                         DBG(cdev, "EEM echo response error\n");
 450                                         goto next;
 451                                 }
 452                                 skb_trim(skb2, len);
 453                                 put_unaligned_le16(BIT(15) | BIT(11) | len,
 454                                                         skb_push(skb2, 2));
 455
 456                                 ep = port->in_ep;
 457                                 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 458                                 if (!req) {
 459                                         dev_kfree_skb_any(skb2);
 460                                         goto next;
 461                                 }
 462
 463                                 req->buf = kmalloc(skb2->len, GFP_KERNEL);
 464                                 if (!req->buf) {
 465                                         usb_ep_free_request(ep, req);
 466                                         dev_kfree_skb_any(skb2);
 467                                         goto next;
 468                                 }
 469
 470                                 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
 471                                 if (!ctx) {
 472                                         kfree(req->buf);
 473                                         usb_ep_free_request(ep, req);
 474                                         dev_kfree_skb_any(skb2);
 475                                         goto next;
 476                                 }
 477                                 ctx->skb = skb2;
 478                                 ctx->ep = ep;
 479
 480                                 skb_copy_bits(skb2, 0, req->buf, skb2->len);
 481                                 req->length = skb2->len;
 482                                 req->complete = eem_cmd_complete;
 483                                 req->zero = 1;
 484                                 req->context = ctx;
 485                                 if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
 486                                         DBG(cdev, "echo response queue fail\n");
 487                                 break;
 488
 489                         case 1:  /* echo response */
 490                         case 2:  /* suspend hint */
 491                         case 3:  /* response hint */
 492                         case 4:  /* response complete hint */
 493                         case 5:  /* tickle */
 494                         default: /* reserved */
 495                                 continue;
 496                         }
 497                 } else {
 498                         u32             crc, crc2;
 499                         struct sk_buff  *skb3;
 500
 501                         /* check for zero-length EEM packet */
 502                         if (header == 0)
 503                                 continue;
 504
 505                         /* EEM data packet format:
 506                          * b0..13:      length of ethernet frame
 507                          * b14:         bmCRC (0 == sentinel, 1 == calculated)
 508                          * b15:         bmType (0 == data)
 509                          */
 510                         len = header & 0x3FFF;
 511                         if ((skb->len < len)
 512                                         || (len < (ETH_HLEN + ETH_FCS_LEN))) {
 513                                 status = -EINVAL;
 514                                 goto error;
 515                         }
 516
 517                         /* validate CRC */
 518                         if (header & BIT(14)) {
 519                                 crc = get_unaligned_le32(skb->data + len
 520                                                         - ETH_FCS_LEN);
 521                                 crc2 = ~crc32_le(~0,
 522                                                 skb->data, len - ETH_FCS_LEN);
 523                         } else {
 524                                 crc = get_unaligned_be32(skb->data + len
 525                                                         - ETH_FCS_LEN);
 526                                 crc2 = 0xdeadbeef;
 527                         }
 528                         if (crc != crc2) {
 529                                 DBG(cdev, "invalid EEM CRC\n");
 530                                 goto next;
 531                         }
 532
 533                         skb2 = skb_clone(skb, GFP_ATOMIC);
 534                         if (unlikely(!skb2)) {
 535                                 DBG(cdev, "unable to unframe EEM packet\n");
 536                                 goto next;
 537                         }
 538                         skb_trim(skb2, len - ETH_FCS_LEN);
 539
 540                         skb3 = skb_copy_expand(skb2,
 541                                                 NET_IP_ALIGN,
 542                                                 0,
 543                                                 GFP_ATOMIC);
 544                         if (unlikely(!skb3)) {
 545                                 dev_kfree_skb_any(skb2);
 546                                 goto next;
 547                         }
 548                         dev_kfree_skb_any(skb2);
 549                         skb_queue_tail(list, skb3);
 550                 }
 551 next:
 552                 skb_pull(skb, len);
 553         } while (skb->len);
 554
 555 error:
 556         dev_kfree_skb_any(skb);
 557         return status;
 558 }
 559
 560 static inline struct f_eem_opts *to_f_eem_opts(struct config_item *item)
 561 {
 562         return container_of(to_config_group(item), struct f_eem_opts,
 563                             func_inst.group);
 564 }
 565
 566 /* f_eem_item_ops */
 567 USB_ETHERNET_CONFIGFS_ITEM(eem);
 568
 569 /* f_eem_opts_dev_addr */
 570 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(eem);
 571
 572 /* f_eem_opts_host_addr */
 573 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(eem);
 574
 575 /* f_eem_opts_qmult */
 576 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(eem);
 577
 578 /* f_eem_opts_ifname */
 579 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(eem);
 580
 581 static struct configfs_attribute *eem_attrs[] = {
 582         &eem_opts_attr_dev_addr,
 583         &eem_opts_attr_host_addr,
 584         &eem_opts_attr_qmult,
 585         &eem_opts_attr_ifname,
 586         NULL,
 587 };
 588
 589 static const struct config_item_type eem_func_type = {
 590         .ct_item_ops    = &eem_item_ops,
 591         .ct_attrs       = eem_attrs,
 592         .ct_owner       = THIS_MODULE,
 593 };
 594
 595 static void eem_free_inst(struct usb_function_instance *f)
 596 {
 597         struct f_eem_opts *opts;
 598
 599         opts = container_of(f, struct f_eem_opts, func_inst);
 600         if (opts->bound)
 601                 gether_cleanup(netdev_priv(opts->net));
 602         else
 603                 free_netdev(opts->net);
 604         kfree(opts);
 605 }
 606
 607 static struct usb_function_instance *eem_alloc_inst(void)
 608 {
 609         struct f_eem_opts *opts;
 610
 611         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 612         if (!opts)
 613                 return ERR_PTR(-ENOMEM);
 614         mutex_init(&opts->lock);
 615         opts->func_inst.free_func_inst = eem_free_inst;
 616         opts->net = gether_setup_default();
 617         if (IS_ERR(opts->net)) {
 618                 struct net_device *net = opts->net;
 619                 kfree(opts);
 620                 return ERR_CAST(net);
 621         }
 622
 623         config_group_init_type_name(&opts->func_inst.group, "", &eem_func_type);
 624
 625         return &opts->func_inst;
 626 }
 627
 628 static void eem_free(struct usb_function *f)
 629 {
 630         struct f_eem *eem;
 631         struct f_eem_opts *opts;
 632
 633         eem = func_to_eem(f);
 634         opts = container_of(f->fi, struct f_eem_opts, func_inst);
 635         kfree(eem);
 636         mutex_lock(&opts->lock);
 637         opts->refcnt--;
 638         mutex_unlock(&opts->lock);
 639 }
 640
 641 static void eem_unbind(struct usb_configuration *c, struct usb_function *f)
 642 {
 643         DBG(c->cdev, "eem unbind\n");
 644
 645         usb_free_all_descriptors(f);
 646 }
 647
 648 static struct usb_function *eem_alloc(struct usb_function_instance *fi)
 649 {
 650         struct f_eem    *eem;
 651         struct f_eem_opts *opts;
 652
 653         /* allocate and initialize one new instance */
 654         eem = kzalloc(sizeof(*eem), GFP_KERNEL);
 655         if (!eem)
 656                 return ERR_PTR(-ENOMEM);
 657
 658         opts = container_of(fi, struct f_eem_opts, func_inst);
 659         mutex_lock(&opts->lock);
 660         opts->refcnt++;
 661
 662         eem->port.ioport = netdev_priv(opts->net);
 663         mutex_unlock(&opts->lock);
 664         eem->port.cdc_filter = DEFAULT_FILTER;
 665
 666         eem->port.func.name = "cdc_eem";
 667         /* descriptors are per-instance copies */
 668         eem->port.func.bind = eem_bind;
 669         eem->port.func.unbind = eem_unbind;
 670         eem->port.func.set_alt = eem_set_alt;
 671         eem->port.func.setup = eem_setup;
 672         eem->port.func.disable = eem_disable;
 673         eem->port.func.free_func = eem_free;
 674         eem->port.wrap = eem_wrap;
 675         eem->port.unwrap = eem_unwrap;
 676         eem->port.header_len = EEM_HLEN;
 677
 678         return &eem->port.func;
 679 }
 680
 681 DECLARE_USB_FUNCTION_INIT(eem, eem_alloc_inst, eem_alloc);
 682 MODULE_LICENSE("GPL");
 683 MODULE_AUTHOR("David Brownell");