drivers/usb/gadget/f_ecm.c

   1 /*
   2  * f_ecm.c -- USB CDC Ethernet (ECM) link function driver
   3  *
   4  * Copyright (C) 2003-2005,2008 David Brownell
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 /* #define VERBOSE_DEBUG */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/etherdevice.h>
  27
  28 #include "u_ether.h"
  29
  30
  31 /*
  32  * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  33  * Ethernet link.  The data transfer model is simple (packets sent and
  34  * received over bulk endpoints using normal short packet termination),
  35  * and the control model exposes various data and optional notifications.
  36  *
  37  * ECM is well standardized and (except for Microsoft) supported by most
  38  * operating systems with USB host support.  It's the preferred interop
  39  * solution for Ethernet over USB, at least for firmware based solutions.
  40  * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  41  * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  42  *
  43  * Note that ECM requires the use of "alternate settings" for its data
  44  * interface.  This means that the set_alt() method has real work to do,
  45  * and also means that a get_alt() method is required.
  46  */
  47
  48 struct ecm_ep_descs {
  49         struct usb_endpoint_descriptor  *in;
  50         struct usb_endpoint_descriptor  *out;
  51         struct usb_endpoint_descriptor  *notify;
  52 };
  53
  54 enum ecm_notify_state {
  55         ECM_NOTIFY_NONE,                /* don't notify */
  56         ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  57         ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  58 };
  59
  60 struct f_ecm {
  61         struct gether                   port;
  62         u8                              ctrl_id, data_id;
  63
  64         char                            ethaddr[14];
  65
  66         struct ecm_ep_descs             fs;
  67         struct ecm_ep_descs             hs;
  68
  69         struct usb_ep                   *notify;
  70         struct usb_endpoint_descriptor  *notify_desc;
  71         struct usb_request              *notify_req;
  72         u8                              notify_state;
  73         bool                            is_open;
  74
  75         /* FIXME is_open needs some irq-ish locking
  76          * ... possibly the same as port.ioport
  77          */
  78 };
  79
  80 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  81 {
  82         return container_of(f, struct f_ecm, port.func);
  83 }
  84
  85 /* peak (theoretical) bulk transfer rate in bits-per-second */
  86 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  87 {
  88         if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  89                 return 13 * 512 * 8 * 1000 * 8;
  90         else
  91                 return 19 *  64 * 1 * 1000 * 8;
  92 }
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /*
  97  * Include the status endpoint if we can, even though it's optional.
  98  *
  99  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
 100  * packet, to simplify cancellation; and a big transfer interval, to
 101  * waste less bandwidth.
 102  *
 103  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
 104  * if they ignore the connect/disconnect notifications that real aether
 105  * can provide.  More advanced cdc configurations might want to support
 106  * encapsulated commands (vendor-specific, using control-OUT).
 107  */
 108
 109 #define LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
 110 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
 111
 112
 113 /* interface descriptor: */
 114
 115 static struct usb_interface_descriptor ecm_control_intf __initdata = {
 116         .bLength =              sizeof ecm_control_intf,
 117         .bDescriptorType =      USB_DT_INTERFACE,
 118
 119         /* .bInterfaceNumber = DYNAMIC */
 120         /* status endpoint is optional; this could be patched later */
 121         .bNumEndpoints =        1,
 122         .bInterfaceClass =      USB_CLASS_COMM,
 123         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 124         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 125         /* .iInterface = DYNAMIC */
 126 };
 127
 128 static struct usb_cdc_header_desc ecm_header_desc __initdata = {
 129         .bLength =              sizeof ecm_header_desc,
 130         .bDescriptorType =      USB_DT_CS_INTERFACE,
 131         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 132
 133         .bcdCDC =               cpu_to_le16(0x0110),
 134 };
 135
 136 static struct usb_cdc_union_desc ecm_union_desc __initdata = {
 137         .bLength =              sizeof(ecm_union_desc),
 138         .bDescriptorType =      USB_DT_CS_INTERFACE,
 139         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 140         /* .bMasterInterface0 = DYNAMIC */
 141         /* .bSlaveInterface0 =  DYNAMIC */
 142 };
 143
 144 static struct usb_cdc_ether_desc ecm_desc __initdata = {
 145         .bLength =              sizeof ecm_desc,
 146         .bDescriptorType =      USB_DT_CS_INTERFACE,
 147         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 148
 149         /* this descriptor actually adds value, surprise! */
 150         /* .iMACAddress = DYNAMIC */
 151         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 152         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 153         .wNumberMCFilters =     cpu_to_le16(0),
 154         .bNumberPowerFilters =  0,
 155 };
 156
 157 /* the default data interface has no endpoints ... */
 158
 159 static struct usb_interface_descriptor ecm_data_nop_intf __initdata = {
 160         .bLength =              sizeof ecm_data_nop_intf,
 161         .bDescriptorType =      USB_DT_INTERFACE,
 162
 163         .bInterfaceNumber =     1,
 164         .bAlternateSetting =    0,
 165         .bNumEndpoints =        0,
 166         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 167         .bInterfaceSubClass =   0,
 168         .bInterfaceProtocol =   0,
 169         /* .iInterface = DYNAMIC */
 170 };
 171
 172 /* ... but the "real" data interface has two bulk endpoints */
 173
 174 static struct usb_interface_descriptor ecm_data_intf __initdata = {
 175         .bLength =              sizeof ecm_data_intf,
 176         .bDescriptorType =      USB_DT_INTERFACE,
 177
 178         .bInterfaceNumber =     1,
 179         .bAlternateSetting =    1,
 180         .bNumEndpoints =        2,
 181         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 182         .bInterfaceSubClass =   0,
 183         .bInterfaceProtocol =   0,
 184         /* .iInterface = DYNAMIC */
 185 };
 186
 187 /* full speed support: */
 188
 189 static struct usb_endpoint_descriptor fs_ecm_notify_desc __initdata = {
 190         .bLength =              USB_DT_ENDPOINT_SIZE,
 191         .bDescriptorType =      USB_DT_ENDPOINT,
 192
 193         .bEndpointAddress =     USB_DIR_IN,
 194         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 195         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 196         .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
 197 };
 198
 199 static struct usb_endpoint_descriptor fs_ecm_in_desc __initdata = {
 200         .bLength =              USB_DT_ENDPOINT_SIZE,
 201         .bDescriptorType =      USB_DT_ENDPOINT,
 202
 203         .bEndpointAddress =     USB_DIR_IN,
 204         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 205 };
 206
 207 static struct usb_endpoint_descriptor fs_ecm_out_desc __initdata = {
 208         .bLength =              USB_DT_ENDPOINT_SIZE,
 209         .bDescriptorType =      USB_DT_ENDPOINT,
 210
 211         .bEndpointAddress =     USB_DIR_OUT,
 212         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 213 };
 214
 215 static struct usb_descriptor_header *ecm_fs_function[] __initdata = {
 216         /* CDC ECM control descriptors */
 217         (struct usb_descriptor_header *) &ecm_control_intf,
 218         (struct usb_descriptor_header *) &ecm_header_desc,
 219         (struct usb_descriptor_header *) &ecm_union_desc,
 220         (struct usb_descriptor_header *) &ecm_desc,
 221         /* NOTE: status endpoint might need to be removed */
 222         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 223         /* data interface, altsettings 0 and 1 */
 224         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 225         (struct usb_descriptor_header *) &ecm_data_intf,
 226         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 227         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 228         NULL,
 229 };
 230
 231 /* high speed support: */
 232
 233 static struct usb_endpoint_descriptor hs_ecm_notify_desc __initdata = {
 234         .bLength =              USB_DT_ENDPOINT_SIZE,
 235         .bDescriptorType =      USB_DT_ENDPOINT,
 236
 237         .bEndpointAddress =     USB_DIR_IN,
 238         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 239         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 240         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 241 };
 242 static struct usb_endpoint_descriptor hs_ecm_in_desc __initdata = {
 243         .bLength =              USB_DT_ENDPOINT_SIZE,
 244         .bDescriptorType =      USB_DT_ENDPOINT,
 245
 246         .bEndpointAddress =     USB_DIR_IN,
 247         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 248         .wMaxPacketSize =       cpu_to_le16(512),
 249 };
 250
 251 static struct usb_endpoint_descriptor hs_ecm_out_desc __initdata = {
 252         .bLength =              USB_DT_ENDPOINT_SIZE,
 253         .bDescriptorType =      USB_DT_ENDPOINT,
 254
 255         .bEndpointAddress =     USB_DIR_OUT,
 256         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 257         .wMaxPacketSize =       cpu_to_le16(512),
 258 };
 259
 260 static struct usb_descriptor_header *ecm_hs_function[] __initdata = {
 261         /* CDC ECM control descriptors */
 262         (struct usb_descriptor_header *) &ecm_control_intf,
 263         (struct usb_descriptor_header *) &ecm_header_desc,
 264         (struct usb_descriptor_header *) &ecm_union_desc,
 265         (struct usb_descriptor_header *) &ecm_desc,
 266         /* NOTE: status endpoint might need to be removed */
 267         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 268         /* data interface, altsettings 0 and 1 */
 269         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 270         (struct usb_descriptor_header *) &ecm_data_intf,
 271         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 272         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 273         NULL,
 274 };
 275
 276 /* string descriptors: */
 277
 278 static struct usb_string ecm_string_defs[] = {
 279         [0].s = "CDC Ethernet Control Model (ECM)",
 280         [1].s = NULL /* DYNAMIC */,
 281         [2].s = "CDC Ethernet Data",
 282         {  } /* end of list */
 283 };
 284
 285 static struct usb_gadget_strings ecm_string_table = {
 286         .language =             0x0409, /* en-us */
 287         .strings =              ecm_string_defs,
 288 };
 289
 290 static struct usb_gadget_strings *ecm_strings[] = {
 291         &ecm_string_table,
 292         NULL,
 293 };
 294
 295 /*-------------------------------------------------------------------------*/
 296
 297 static void ecm_do_notify(struct f_ecm *ecm)
 298 {
 299         struct usb_request              *req = ecm->notify_req;
 300         struct usb_cdc_notification     *event;
 301         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 302         __le32                          *data;
 303         int                             status;
 304
 305         /* notification already in flight? */
 306         if (!req)
 307                 return;
 308
 309         event = req->buf;
 310         switch (ecm->notify_state) {
 311         case ECM_NOTIFY_NONE:
 312                 return;
 313
 314         case ECM_NOTIFY_CONNECT:
 315                 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 316                 if (ecm->is_open)
 317                         event->wValue = cpu_to_le16(1);
 318                 else
 319                         event->wValue = cpu_to_le16(0);
 320                 event->wLength = 0;
 321                 req->length = sizeof *event;
 322
 323                 DBG(cdev, "notify connect %s\n",
 324                                 ecm->is_open ? "true" : "false");
 325                 ecm->notify_state = ECM_NOTIFY_SPEED;
 326                 break;
 327
 328         case ECM_NOTIFY_SPEED:
 329                 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 330                 event->wValue = cpu_to_le16(0);
 331                 event->wLength = cpu_to_le16(8);
 332                 req->length = ECM_STATUS_BYTECOUNT;
 333
 334                 /* SPEED_CHANGE data is up/down speeds in bits/sec */
 335                 data = req->buf + sizeof *event;
 336                 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 337                 data[1] = data[0];
 338
 339                 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 340                 ecm->notify_state = ECM_NOTIFY_NONE;
 341                 break;
 342         }
 343         event->bmRequestType = 0xA1;
 344         event->wIndex = cpu_to_le16(ecm->ctrl_id);
 345
 346         ecm->notify_req = NULL;
 347         status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 348         if (status < 0) {
 349                 ecm->notify_req = req;
 350                 DBG(cdev, "notify --> %d\n", status);
 351         }
 352 }
 353
 354 static void ecm_notify(struct f_ecm *ecm)
 355 {
 356         /* NOTE on most versions of Linux, host side cdc-ethernet
 357          * won't listen for notifications until its netdevice opens.
 358          * The first notification then sits in the FIFO for a long
 359          * time, and the second one is queued.
 360          */
 361         ecm->notify_state = ECM_NOTIFY_CONNECT;
 362         ecm_do_notify(ecm);
 363 }
 364
 365 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 366 {
 367         struct f_ecm                    *ecm = req->context;
 368         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 369         struct usb_cdc_notification     *event = req->buf;
 370
 371         switch (req->status) {
 372         case 0:
 373                 /* no fault */
 374                 break;
 375         case -ECONNRESET:
 376         case -ESHUTDOWN:
 377                 ecm->notify_state = ECM_NOTIFY_NONE;
 378                 break;
 379         default:
 380                 DBG(cdev, "event %02x --> %d\n",
 381                         event->bNotificationType, req->status);
 382                 break;
 383         }
 384         ecm->notify_req = req;
 385         ecm_do_notify(ecm);
 386 }
 387
 388 static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 389 {
 390         struct f_ecm            *ecm = func_to_ecm(f);
 391         struct usb_composite_dev *cdev = f->config->cdev;
 392         struct usb_request      *req = cdev->req;
 393         int                     value = -EOPNOTSUPP;
 394         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 395         u16                     w_value = le16_to_cpu(ctrl->wValue);
 396         u16                     w_length = le16_to_cpu(ctrl->wLength);
 397
 398         /* composite driver infrastructure handles everything except
 399          * CDC class messages; interface activation uses set_alt().
 400          */
 401         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 402         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 403                         | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 404                 /* see 6.2.30: no data, wIndex = interface,
 405                  * wValue = packet filter bitmap
 406                  */
 407                 if (w_length != 0 || w_index != ecm->ctrl_id)
 408                         goto invalid;
 409                 DBG(cdev, "packet filter %02x\n", w_value);
 410                 /* REVISIT locking of cdc_filter.  This assumes the UDC
 411                  * driver won't have a concurrent packet TX irq running on
 412                  * another CPU; or that if it does, this write is atomic...
 413                  */
 414                 ecm->port.cdc_filter = w_value;
 415                 value = 0;
 416                 break;
 417
 418         /* and optionally:
 419          * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 420          * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 421          * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 422          * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 423          * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 424          * case USB_CDC_GET_ETHERNET_STATISTIC:
 425          */
 426
 427         default:
 428 invalid:
 429                 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 430                         ctrl->bRequestType, ctrl->bRequest,
 431                         w_value, w_index, w_length);
 432         }
 433
 434         /* respond with data transfer or status phase? */
 435         if (value >= 0) {
 436                 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 437                         ctrl->bRequestType, ctrl->bRequest,
 438                         w_value, w_index, w_length);
 439                 req->zero = 0;
 440                 req->length = value;
 441                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 442                 if (value < 0)
 443                         ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 444                                         ctrl->bRequestType, ctrl->bRequest,
 445                                         value);
 446         }
 447
 448         /* device either stalls (value < 0) or reports success */
 449         return value;
 450 }
 451
 452
 453 static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 454 {
 455         struct f_ecm            *ecm = func_to_ecm(f);
 456         struct usb_composite_dev *cdev = f->config->cdev;
 457
 458         /* Control interface has only altsetting 0 */
 459         if (intf == ecm->ctrl_id) {
 460                 if (alt != 0)
 461                         goto fail;
 462
 463                 if (ecm->notify->driver_data) {
 464                         VDBG(cdev, "reset ecm control %d\n", intf);
 465                         usb_ep_disable(ecm->notify);
 466                 } else {
 467                         VDBG(cdev, "init ecm ctrl %d\n", intf);
 468                         ecm->notify_desc = ep_choose(cdev->gadget,
 469                                         ecm->hs.notify,
 470                                         ecm->fs.notify);
 471                 }
 472                 usb_ep_enable(ecm->notify, ecm->notify_desc);
 473                 ecm->notify->driver_data = ecm;
 474
 475         /* Data interface has two altsettings, 0 and 1 */
 476         } else if (intf == ecm->data_id) {
 477                 if (alt > 1)
 478                         goto fail;
 479
 480                 if (ecm->port.in_ep->driver_data) {
 481                         DBG(cdev, "reset ecm\n");
 482                         gether_disconnect(&ecm->port);
 483                 }
 484
 485                 if (!ecm->port.in) {
 486                         DBG(cdev, "init ecm\n");
 487                         ecm->port.in = ep_choose(cdev->gadget,
 488                                         ecm->hs.in, ecm->fs.in);
 489                         ecm->port.out = ep_choose(cdev->gadget,
 490                                         ecm->hs.out, ecm->fs.out);
 491                 }
 492
 493                 /* CDC Ethernet only sends data in non-default altsettings.
 494                  * Changing altsettings resets filters, statistics, etc.
 495                  */
 496                 if (alt == 1) {
 497                         struct net_device       *net;
 498
 499                         /* Enable zlps by default for ECM conformance;
 500                          * override for musb_hdrc (avoids txdma ovhead)
 501                          * and sa1100 (can't).
 502                          */
 503                         ecm->port.is_zlp_ok = !(
 504                                    gadget_is_sa1100(cdev->gadget)
 505                                 || gadget_is_musbhdrc(cdev->gadget)
 506                                 );
 507                         ecm->port.cdc_filter = DEFAULT_FILTER;
 508                         DBG(cdev, "activate ecm\n");
 509                         net = gether_connect(&ecm->port);
 510                         if (IS_ERR(net))
 511                                 return PTR_ERR(net);
 512                 }
 513
 514                 /* NOTE this can be a minor disagreement with the ECM spec,
 515                  * which says speed notifications will "always" follow
 516                  * connection notifications.  But we allow one connect to
 517                  * follow another (if the first is in flight), and instead
 518                  * just guarantee that a speed notification is always sent.
 519                  */
 520                 ecm_notify(ecm);
 521         } else
 522                 goto fail;
 523
 524         return 0;
 525 fail:
 526         return -EINVAL;
 527 }
 528
 529 /* Because the data interface supports multiple altsettings,
 530  * this ECM function *MUST* implement a get_alt() method.
 531  */
 532 static int ecm_get_alt(struct usb_function *f, unsigned intf)
 533 {
 534         struct f_ecm            *ecm = func_to_ecm(f);
 535
 536         if (intf == ecm->ctrl_id)
 537                 return 0;
 538         return ecm->port.in_ep->driver_data ? 1 : 0;
 539 }
 540
 541 static void ecm_disable(struct usb_function *f)
 542 {
 543         struct f_ecm            *ecm = func_to_ecm(f);
 544         struct usb_composite_dev *cdev = f->config->cdev;
 545
 546         DBG(cdev, "ecm deactivated\n");
 547
 548         if (ecm->port.in_ep->driver_data)
 549                 gether_disconnect(&ecm->port);
 550
 551         if (ecm->notify->driver_data) {
 552                 usb_ep_disable(ecm->notify);
 553                 ecm->notify->driver_data = NULL;
 554                 ecm->notify_desc = NULL;
 555         }
 556 }
 557
 558 /*-------------------------------------------------------------------------*/
 559
 560 /*
 561  * Callbacks let us notify the host about connect/disconnect when the
 562  * net device is opened or closed.
 563  *
 564  * For testing, note that link states on this side include both opened
 565  * and closed variants of:
 566  *
 567  *   - disconnected/unconfigured
 568  *   - configured but inactive (data alt 0)
 569  *   - configured and active (data alt 1)
 570  *
 571  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 572  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 573  * imply the host is actually polling the notification endpoint, and
 574  * likewise that "active" doesn't imply it's actually using the data
 575  * endpoints for traffic.
 576  */
 577
 578 static void ecm_open(struct gether *geth)
 579 {
 580         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 581
 582         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 583
 584         ecm->is_open = true;
 585         ecm_notify(ecm);
 586 }
 587
 588 static void ecm_close(struct gether *geth)
 589 {
 590         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 591
 592         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 593
 594         ecm->is_open = false;
 595         ecm_notify(ecm);
 596 }
 597
 598 /*-------------------------------------------------------------------------*/
 599
 600 /* ethernet function driver setup/binding */
 601
 602 static int __init
 603 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 604 {
 605         struct usb_composite_dev *cdev = c->cdev;
 606         struct f_ecm            *ecm = func_to_ecm(f);
 607         int                     status;
 608         struct usb_ep           *ep;
 609
 610         /* allocate instance-specific interface IDs */
 611         status = usb_interface_id(c, f);
 612         if (status < 0)
 613                 goto fail;
 614         ecm->ctrl_id = status;
 615
 616         ecm_control_intf.bInterfaceNumber = status;
 617         ecm_union_desc.bMasterInterface0 = status;
 618
 619         status = usb_interface_id(c, f);
 620         if (status < 0)
 621                 goto fail;
 622         ecm->data_id = status;
 623
 624         ecm_data_nop_intf.bInterfaceNumber = status;
 625         ecm_data_intf.bInterfaceNumber = status;
 626         ecm_union_desc.bSlaveInterface0 = status;
 627
 628         status = -ENODEV;
 629
 630         /* allocate instance-specific endpoints */
 631         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 632         if (!ep)
 633                 goto fail;
 634         ecm->port.in_ep = ep;
 635         ep->driver_data = cdev; /* claim */
 636
 637         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 638         if (!ep)
 639                 goto fail;
 640         ecm->port.out_ep = ep;
 641         ep->driver_data = cdev; /* claim */
 642
 643         /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 644          * don't treat it that way.  It's simpler, and some newer CDC
 645          * profiles (wireless handsets) no longer treat it as optional.
 646          */
 647         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 648         if (!ep)
 649                 goto fail;
 650         ecm->notify = ep;
 651         ep->driver_data = cdev; /* claim */
 652
 653         status = -ENOMEM;
 654
 655         /* allocate notification request and buffer */
 656         ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 657         if (!ecm->notify_req)
 658                 goto fail;
 659         ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 660         if (!ecm->notify_req->buf)
 661                 goto fail;
 662         ecm->notify_req->context = ecm;
 663         ecm->notify_req->complete = ecm_notify_complete;
 664
 665         /* copy descriptors, and track endpoint copies */
 666         f->descriptors = usb_copy_descriptors(ecm_fs_function);
 667         if (!f->descriptors)
 668                 goto fail;
 669
 670         ecm->fs.in = usb_find_endpoint(ecm_fs_function,
 671                         f->descriptors, &fs_ecm_in_desc);
 672         ecm->fs.out = usb_find_endpoint(ecm_fs_function,
 673                         f->descriptors, &fs_ecm_out_desc);
 674         ecm->fs.notify = usb_find_endpoint(ecm_fs_function,
 675                         f->descriptors, &fs_ecm_notify_desc);
 676
 677         /* support all relevant hardware speeds... we expect that when
 678          * hardware is dual speed, all bulk-capable endpoints work at
 679          * both speeds
 680          */
 681         if (gadget_is_dualspeed(c->cdev->gadget)) {
 682                 hs_ecm_in_desc.bEndpointAddress =
 683                                 fs_ecm_in_desc.bEndpointAddress;
 684                 hs_ecm_out_desc.bEndpointAddress =
 685                                 fs_ecm_out_desc.bEndpointAddress;
 686                 hs_ecm_notify_desc.bEndpointAddress =
 687                                 fs_ecm_notify_desc.bEndpointAddress;
 688
 689                 /* copy descriptors, and track endpoint copies */
 690                 f->hs_descriptors = usb_copy_descriptors(ecm_hs_function);
 691                 if (!f->hs_descriptors)
 692                         goto fail;
 693
 694                 ecm->hs.in = usb_find_endpoint(ecm_hs_function,
 695                                 f->hs_descriptors, &hs_ecm_in_desc);
 696                 ecm->hs.out = usb_find_endpoint(ecm_hs_function,
 697                                 f->hs_descriptors, &hs_ecm_out_desc);
 698                 ecm->hs.notify = usb_find_endpoint(ecm_hs_function,
 699                                 f->hs_descriptors, &hs_ecm_notify_desc);
 700         }
 701
 702         /* NOTE:  all that is done without knowing or caring about
 703          * the network link ... which is unavailable to this code
 704          * until we're activated via set_alt().
 705          */
 706
 707         ecm->port.open = ecm_open;
 708         ecm->port.close = ecm_close;
 709
 710         DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 711                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 712                         ecm->port.in_ep->name, ecm->port.out_ep->name,
 713                         ecm->notify->name);
 714         return 0;
 715
 716 fail:
 717         if (f->descriptors)
 718                 usb_free_descriptors(f->descriptors);
 719
 720         if (ecm->notify_req) {
 721                 kfree(ecm->notify_req->buf);
 722                 usb_ep_free_request(ecm->notify, ecm->notify_req);
 723         }
 724
 725         /* we might as well release our claims on endpoints */
 726         if (ecm->notify)
 727                 ecm->notify->driver_data = NULL;
 728         if (ecm->port.out)
 729                 ecm->port.out_ep->driver_data = NULL;
 730         if (ecm->port.in)
 731                 ecm->port.in_ep->driver_data = NULL;
 732
 733         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 734
 735         return status;
 736 }
 737
 738 static void
 739 ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 740 {
 741         struct f_ecm            *ecm = func_to_ecm(f);
 742
 743         DBG(c->cdev, "ecm unbind\n");
 744
 745         if (gadget_is_dualspeed(c->cdev->gadget))
 746                 usb_free_descriptors(f->hs_descriptors);
 747         usb_free_descriptors(f->descriptors);
 748
 749         kfree(ecm->notify_req->buf);
 750         usb_ep_free_request(ecm->notify, ecm->notify_req);
 751
 752         ecm_string_defs[1].s = NULL;
 753         kfree(ecm);
 754 }
 755
 756 /**
 757  * ecm_bind_config - add CDC Ethernet network link to a configuration
 758  * @c: the configuration to support the network link
 759  * @ethaddr: a buffer in which the ethernet address of the host side
 760  *      side of the link was recorded
 761  * Context: single threaded during gadget setup
 762  *
 763  * Returns zero on success, else negative errno.
 764  *
 765  * Caller must have called @gether_setup().  Caller is also responsible
 766  * for calling @gether_cleanup() before module unload.
 767  */
 768 int __init ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 769 {
 770         struct f_ecm    *ecm;
 771         int             status;
 772
 773         if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
 774                 return -EINVAL;
 775
 776         /* maybe allocate device-global string IDs */
 777         if (ecm_string_defs[0].id == 0) {
 778
 779                 /* control interface label */
 780                 status = usb_string_id(c->cdev);
 781                 if (status < 0)
 782                         return status;
 783                 ecm_string_defs[0].id = status;
 784                 ecm_control_intf.iInterface = status;
 785
 786                 /* data interface label */
 787                 status = usb_string_id(c->cdev);
 788                 if (status < 0)
 789                         return status;
 790                 ecm_string_defs[2].id = status;
 791                 ecm_data_intf.iInterface = status;
 792
 793                 /* MAC address */
 794                 status = usb_string_id(c->cdev);
 795                 if (status < 0)
 796                         return status;
 797                 ecm_string_defs[1].id = status;
 798                 ecm_desc.iMACAddress = status;
 799         }
 800
 801         /* allocate and initialize one new instance */
 802         ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
 803         if (!ecm)
 804                 return -ENOMEM;
 805
 806         /* export host's Ethernet address in CDC format */
 807         snprintf(ecm->ethaddr, sizeof ecm->ethaddr,
 808                 "%02X%02X%02X%02X%02X%02X",
 809                 ethaddr[0], ethaddr[1], ethaddr[2],
 810                 ethaddr[3], ethaddr[4], ethaddr[5]);
 811         ecm_string_defs[1].s = ecm->ethaddr;
 812
 813         ecm->port.cdc_filter = DEFAULT_FILTER;
 814
 815         ecm->port.func.name = "cdc_ethernet";
 816         ecm->port.func.strings = ecm_strings;
 817         /* descriptors are per-instance copies */
 818         ecm->port.func.bind = ecm_bind;
 819         ecm->port.func.unbind = ecm_unbind;
 820         ecm->port.func.set_alt = ecm_set_alt;
 821         ecm->port.func.get_alt = ecm_get_alt;
 822         ecm->port.func.setup = ecm_setup;
 823         ecm->port.func.disable = ecm_disable;
 824
 825         status = usb_add_function(c, &ecm->port.func);
 826         if (status) {
 827                 ecm_string_defs[1].s = NULL;
 828                 kfree(ecm);
 829         }
 830         return status;
 831 }