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
  13 /* #define VERBOSE_DEBUG */
  14
  15 #include <linux/slab.h>
  16 #include <linux/kernel.h>
  17 #include <linux/device.h>
  18 #include <linux/etherdevice.h>
  19
  20 #include "u_ether.h"
  21
  22
  23 /*
  24  * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  25  * Ethernet link.  The data transfer model is simple (packets sent and
  26  * received over bulk endpoints using normal short packet termination),
  27  * and the control model exposes various data and optional notifications.
  28  *
  29  * ECM is well standardized and (except for Microsoft) supported by most
  30  * operating systems with USB host support.  It's the preferred interop
  31  * solution for Ethernet over USB, at least for firmware based solutions.
  32  * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  33  * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  34  *
  35  * Note that ECM requires the use of "alternate settings" for its data
  36  * interface.  This means that the set_alt() method has real work to do,
  37  * and also means that a get_alt() method is required.
  38  */
  39
  40
  41 enum ecm_notify_state {
  42         ECM_NOTIFY_NONE,                /* don't notify */
  43         ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  44         ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  45 };
  46
  47 struct f_ecm {
  48         struct gether                   port;
  49         u8                              ctrl_id, data_id;
  50
  51         char                            ethaddr[14];
  52
  53         struct usb_ep                   *notify;
  54         struct usb_request              *notify_req;
  55         u8                              notify_state;
  56         bool                            is_open;
  57
  58         /* FIXME is_open needs some irq-ish locking
  59          * ... possibly the same as port.ioport
  60          */
  61 };
  62
  63 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  64 {
  65         return container_of(f, struct f_ecm, port.func);
  66 }
  67
  68 /* peak (theoretical) bulk transfer rate in bits-per-second */
  69 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  70 {
  71         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  72                 return 13 * 1024 * 8 * 1000 * 8;
  73         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  74                 return 13 * 512 * 8 * 1000 * 8;
  75         else
  76                 return 19 * 64 * 1 * 1000 * 8;
  77 }
  78
  79 /*-------------------------------------------------------------------------*/
  80
  81 /*
  82  * Include the status endpoint if we can, even though it's optional.
  83  *
  84  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
  85  * packet, to simplify cancellation; and a big transfer interval, to
  86  * waste less bandwidth.
  87  *
  88  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
  89  * if they ignore the connect/disconnect notifications that real aether
  90  * can provide.  More advanced cdc configurations might want to support
  91  * encapsulated commands (vendor-specific, using control-OUT).
  92  */
  93
  94 #define ECM_STATUS_INTERVAL_MS          32
  95 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  96
  97
  98 /* interface descriptor: */
  99
 100 static struct usb_interface_assoc_descriptor
 101 ecm_iad_descriptor = {
 102         .bLength =              sizeof ecm_iad_descriptor,
 103         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 104
 105         /* .bFirstInterface =   DYNAMIC, */
 106         .bInterfaceCount =      2,      /* control + data */
 107         .bFunctionClass =       USB_CLASS_COMM,
 108         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 109         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 110         /* .iFunction =         DYNAMIC */
 111 };
 112
 113
 114 static struct usb_interface_descriptor ecm_control_intf = {
 115         .bLength =              sizeof ecm_control_intf,
 116         .bDescriptorType =      USB_DT_INTERFACE,
 117
 118         /* .bInterfaceNumber = DYNAMIC */
 119         /* status endpoint is optional; this could be patched later */
 120         .bNumEndpoints =        1,
 121         .bInterfaceClass =      USB_CLASS_COMM,
 122         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 123         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 124         /* .iInterface = DYNAMIC */
 125 };
 126
 127 static struct usb_cdc_header_desc ecm_header_desc = {
 128         .bLength =              sizeof ecm_header_desc,
 129         .bDescriptorType =      USB_DT_CS_INTERFACE,
 130         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 131
 132         .bcdCDC =               cpu_to_le16(0x0110),
 133 };
 134
 135 static struct usb_cdc_union_desc ecm_union_desc = {
 136         .bLength =              sizeof(ecm_union_desc),
 137         .bDescriptorType =      USB_DT_CS_INTERFACE,
 138         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 139         /* .bMasterInterface0 = DYNAMIC */
 140         /* .bSlaveInterface0 =  DYNAMIC */
 141 };
 142
 143 static struct usb_cdc_ether_desc ecm_desc = {
 144         .bLength =              sizeof ecm_desc,
 145         .bDescriptorType =      USB_DT_CS_INTERFACE,
 146         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 147
 148         /* this descriptor actually adds value, surprise! */
 149         /* .iMACAddress = DYNAMIC */
 150         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 151         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 152         .wNumberMCFilters =     cpu_to_le16(0),
 153         .bNumberPowerFilters =  0,
 154 };
 155
 156 /* the default data interface has no endpoints ... */
 157
 158 static struct usb_interface_descriptor ecm_data_nop_intf = {
 159         .bLength =              sizeof ecm_data_nop_intf,
 160         .bDescriptorType =      USB_DT_INTERFACE,
 161
 162         .bInterfaceNumber =     1,
 163         .bAlternateSetting =    0,
 164         .bNumEndpoints =        0,
 165         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 166         .bInterfaceSubClass =   0,
 167         .bInterfaceProtocol =   0,
 168         /* .iInterface = DYNAMIC */
 169 };
 170
 171 /* ... but the "real" data interface has two bulk endpoints */
 172
 173 static struct usb_interface_descriptor ecm_data_intf = {
 174         .bLength =              sizeof ecm_data_intf,
 175         .bDescriptorType =      USB_DT_INTERFACE,
 176
 177         .bInterfaceNumber =     1,
 178         .bAlternateSetting =    1,
 179         .bNumEndpoints =        2,
 180         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 181         .bInterfaceSubClass =   0,
 182         .bInterfaceProtocol =   0,
 183         /* .iInterface = DYNAMIC */
 184 };
 185
 186 /* full speed support: */
 187
 188 static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 189         .bLength =              USB_DT_ENDPOINT_SIZE,
 190         .bDescriptorType =      USB_DT_ENDPOINT,
 191
 192         .bEndpointAddress =     USB_DIR_IN,
 193         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 194         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 195         .bInterval =            ECM_STATUS_INTERVAL_MS,
 196 };
 197
 198 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 199         .bLength =              USB_DT_ENDPOINT_SIZE,
 200         .bDescriptorType =      USB_DT_ENDPOINT,
 201
 202         .bEndpointAddress =     USB_DIR_IN,
 203         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 204 };
 205
 206 static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 207         .bLength =              USB_DT_ENDPOINT_SIZE,
 208         .bDescriptorType =      USB_DT_ENDPOINT,
 209
 210         .bEndpointAddress =     USB_DIR_OUT,
 211         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 212 };
 213
 214 static struct usb_descriptor_header *ecm_fs_function[] = {
 215         /* CDC ECM control descriptors */
 216         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 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
 222         /* NOTE: status endpoint might need to be removed */
 223         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 224
 225         /* data interface, altsettings 0 and 1 */
 226         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 227         (struct usb_descriptor_header *) &ecm_data_intf,
 228         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 229         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 230         NULL,
 231 };
 232
 233 /* high speed support: */
 234
 235 static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 236         .bLength =              USB_DT_ENDPOINT_SIZE,
 237         .bDescriptorType =      USB_DT_ENDPOINT,
 238
 239         .bEndpointAddress =     USB_DIR_IN,
 240         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 241         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 242         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 243 };
 244
 245 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 246         .bLength =              USB_DT_ENDPOINT_SIZE,
 247         .bDescriptorType =      USB_DT_ENDPOINT,
 248
 249         .bEndpointAddress =     USB_DIR_IN,
 250         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 251         .wMaxPacketSize =       cpu_to_le16(512),
 252 };
 253
 254 static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 255         .bLength =              USB_DT_ENDPOINT_SIZE,
 256         .bDescriptorType =      USB_DT_ENDPOINT,
 257
 258         .bEndpointAddress =     USB_DIR_OUT,
 259         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 260         .wMaxPacketSize =       cpu_to_le16(512),
 261 };
 262
 263 static struct usb_descriptor_header *ecm_hs_function[] = {
 264         /* CDC ECM control descriptors */
 265         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 266         (struct usb_descriptor_header *) &ecm_control_intf,
 267         (struct usb_descriptor_header *) &ecm_header_desc,
 268         (struct usb_descriptor_header *) &ecm_union_desc,
 269         (struct usb_descriptor_header *) &ecm_desc,
 270
 271         /* NOTE: status endpoint might need to be removed */
 272         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 273
 274         /* data interface, altsettings 0 and 1 */
 275         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 276         (struct usb_descriptor_header *) &ecm_data_intf,
 277         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 278         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 279         NULL,
 280 };
 281
 282 /* super speed support: */
 283
 284 static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 285         .bLength =              USB_DT_ENDPOINT_SIZE,
 286         .bDescriptorType =      USB_DT_ENDPOINT,
 287
 288         .bEndpointAddress =     USB_DIR_IN,
 289         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 290         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 291         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 292 };
 293
 294 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 295         .bLength =              sizeof ss_ecm_intr_comp_desc,
 296         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 297
 298         /* the following 3 values can be tweaked if necessary */
 299         /* .bMaxBurst =         0, */
 300         /* .bmAttributes =      0, */
 301         .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 302 };
 303
 304 static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 305         .bLength =              USB_DT_ENDPOINT_SIZE,
 306         .bDescriptorType =      USB_DT_ENDPOINT,
 307
 308         .bEndpointAddress =     USB_DIR_IN,
 309         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 310         .wMaxPacketSize =       cpu_to_le16(1024),
 311 };
 312
 313 static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 314         .bLength =              USB_DT_ENDPOINT_SIZE,
 315         .bDescriptorType =      USB_DT_ENDPOINT,
 316
 317         .bEndpointAddress =     USB_DIR_OUT,
 318         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 319         .wMaxPacketSize =       cpu_to_le16(1024),
 320 };
 321
 322 static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 323         .bLength =              sizeof ss_ecm_bulk_comp_desc,
 324         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 325
 326         /* the following 2 values can be tweaked if necessary */
 327         /* .bMaxBurst =         0, */
 328         /* .bmAttributes =      0, */
 329 };
 330
 331 static struct usb_descriptor_header *ecm_ss_function[] = {
 332         /* CDC ECM control descriptors */
 333         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 334         (struct usb_descriptor_header *) &ecm_control_intf,
 335         (struct usb_descriptor_header *) &ecm_header_desc,
 336         (struct usb_descriptor_header *) &ecm_union_desc,
 337         (struct usb_descriptor_header *) &ecm_desc,
 338
 339         /* NOTE: status endpoint might need to be removed */
 340         (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 341         (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 342
 343         /* data interface, altsettings 0 and 1 */
 344         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 345         (struct usb_descriptor_header *) &ecm_data_intf,
 346         (struct usb_descriptor_header *) &ss_ecm_in_desc,
 347         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 348         (struct usb_descriptor_header *) &ss_ecm_out_desc,
 349         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 350         NULL,
 351 };
 352
 353 /* string descriptors: */
 354
 355 static struct usb_string ecm_string_defs[] = {
 356         [0].s = "CDC Ethernet Control Model (ECM)",
 357         [1].s = "",
 358         [2].s = "CDC Ethernet Data",
 359         [3].s = "CDC ECM",
 360         {  } /* end of list */
 361 };
 362
 363 static struct usb_gadget_strings ecm_string_table = {
 364         .language =             0x0409, /* en-us */
 365         .strings =              ecm_string_defs,
 366 };
 367
 368 static struct usb_gadget_strings *ecm_strings[] = {
 369         &ecm_string_table,
 370         NULL,
 371 };
 372
 373 /*-------------------------------------------------------------------------*/
 374
 375 static void ecm_do_notify(struct f_ecm *ecm)
 376 {
 377         struct usb_request              *req = ecm->notify_req;
 378         struct usb_cdc_notification     *event;
 379         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 380         __le32                          *data;
 381         int                             status;
 382
 383         /* notification already in flight? */
 384         if (!req)
 385                 return;
 386
 387         event = req->buf;
 388         switch (ecm->notify_state) {
 389         case ECM_NOTIFY_NONE:
 390                 return;
 391
 392         case ECM_NOTIFY_CONNECT:
 393                 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 394                 if (ecm->is_open)
 395                         event->wValue = cpu_to_le16(1);
 396                 else
 397                         event->wValue = cpu_to_le16(0);
 398                 event->wLength = 0;
 399                 req->length = sizeof *event;
 400
 401                 DBG(cdev, "notify connect %s\n",
 402                                 ecm->is_open ? "true" : "false");
 403                 ecm->notify_state = ECM_NOTIFY_SPEED;
 404                 break;
 405
 406         case ECM_NOTIFY_SPEED:
 407                 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 408                 event->wValue = cpu_to_le16(0);
 409                 event->wLength = cpu_to_le16(8);
 410                 req->length = ECM_STATUS_BYTECOUNT;
 411
 412                 /* SPEED_CHANGE data is up/down speeds in bits/sec */
 413                 data = req->buf + sizeof *event;
 414                 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 415                 data[1] = data[0];
 416
 417                 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 418                 ecm->notify_state = ECM_NOTIFY_NONE;
 419                 break;
 420         }
 421         event->bmRequestType = 0xA1;
 422         event->wIndex = cpu_to_le16(ecm->ctrl_id);
 423
 424         ecm->notify_req = NULL;
 425         status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 426         if (status < 0) {
 427                 ecm->notify_req = req;
 428                 DBG(cdev, "notify --> %d\n", status);
 429         }
 430 }
 431
 432 static void ecm_notify(struct f_ecm *ecm)
 433 {
 434         /* NOTE on most versions of Linux, host side cdc-ethernet
 435          * won't listen for notifications until its netdevice opens.
 436          * The first notification then sits in the FIFO for a long
 437          * time, and the second one is queued.
 438          */
 439         ecm->notify_state = ECM_NOTIFY_CONNECT;
 440         ecm_do_notify(ecm);
 441 }
 442
 443 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 444 {
 445         struct f_ecm                    *ecm = req->context;
 446         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 447         struct usb_cdc_notification     *event = req->buf;
 448
 449         switch (req->status) {
 450         case 0:
 451                 /* no fault */
 452                 break;
 453         case -ECONNRESET:
 454         case -ESHUTDOWN:
 455                 ecm->notify_state = ECM_NOTIFY_NONE;
 456                 break;
 457         default:
 458                 DBG(cdev, "event %02x --> %d\n",
 459                         event->bNotificationType, req->status);
 460                 break;
 461         }
 462         ecm->notify_req = req;
 463         ecm_do_notify(ecm);
 464 }
 465
 466 static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 467 {
 468         struct f_ecm            *ecm = func_to_ecm(f);
 469         struct usb_composite_dev *cdev = f->config->cdev;
 470         struct usb_request      *req = cdev->req;
 471         int                     value = -EOPNOTSUPP;
 472         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 473         u16                     w_value = le16_to_cpu(ctrl->wValue);
 474         u16                     w_length = le16_to_cpu(ctrl->wLength);
 475
 476         /* composite driver infrastructure handles everything except
 477          * CDC class messages; interface activation uses set_alt().
 478          */
 479         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 480         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 481                         | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 482                 /* see 6.2.30: no data, wIndex = interface,
 483                  * wValue = packet filter bitmap
 484                  */
 485                 if (w_length != 0 || w_index != ecm->ctrl_id)
 486                         goto invalid;
 487                 DBG(cdev, "packet filter %02x\n", w_value);
 488                 /* REVISIT locking of cdc_filter.  This assumes the UDC
 489                  * driver won't have a concurrent packet TX irq running on
 490                  * another CPU; or that if it does, this write is atomic...
 491                  */
 492                 ecm->port.cdc_filter = w_value;
 493                 value = 0;
 494                 break;
 495
 496         /* and optionally:
 497          * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 498          * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 499          * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 500          * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 501          * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 502          * case USB_CDC_GET_ETHERNET_STATISTIC:
 503          */
 504
 505         default:
 506 invalid:
 507                 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 508                         ctrl->bRequestType, ctrl->bRequest,
 509                         w_value, w_index, w_length);
 510         }
 511
 512         /* respond with data transfer or status phase? */
 513         if (value >= 0) {
 514                 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 515                         ctrl->bRequestType, ctrl->bRequest,
 516                         w_value, w_index, w_length);
 517                 req->zero = 0;
 518                 req->length = value;
 519                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 520                 if (value < 0)
 521                         ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 522                                         ctrl->bRequestType, ctrl->bRequest,
 523                                         value);
 524         }
 525
 526         /* device either stalls (value < 0) or reports success */
 527         return value;
 528 }
 529
 530
 531 static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 532 {
 533         struct f_ecm            *ecm = func_to_ecm(f);
 534         struct usb_composite_dev *cdev = f->config->cdev;
 535
 536         /* Control interface has only altsetting 0 */
 537         if (intf == ecm->ctrl_id) {
 538                 if (alt != 0)
 539                         goto fail;
 540
 541                 if (ecm->notify->driver_data) {
 542                         VDBG(cdev, "reset ecm control %d\n", intf);
 543                         usb_ep_disable(ecm->notify);
 544                 }
 545                 if (!(ecm->notify->desc)) {
 546                         VDBG(cdev, "init ecm ctrl %d\n", intf);
 547                         if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 548                                 goto fail;
 549                 }
 550                 usb_ep_enable(ecm->notify);
 551                 ecm->notify->driver_data = ecm;
 552
 553         /* Data interface has two altsettings, 0 and 1 */
 554         } else if (intf == ecm->data_id) {
 555                 if (alt > 1)
 556                         goto fail;
 557
 558                 if (ecm->port.in_ep->driver_data) {
 559                         DBG(cdev, "reset ecm\n");
 560                         gether_disconnect(&ecm->port);
 561                 }
 562
 563                 if (!ecm->port.in_ep->desc ||
 564                     !ecm->port.out_ep->desc) {
 565                         DBG(cdev, "init ecm\n");
 566                         if (config_ep_by_speed(cdev->gadget, f,
 567                                                ecm->port.in_ep) ||
 568                             config_ep_by_speed(cdev->gadget, f,
 569                                                ecm->port.out_ep)) {
 570                                 ecm->port.in_ep->desc = NULL;
 571                                 ecm->port.out_ep->desc = NULL;
 572                                 goto fail;
 573                         }
 574                 }
 575
 576                 /* CDC Ethernet only sends data in non-default altsettings.
 577                  * Changing altsettings resets filters, statistics, etc.
 578                  */
 579                 if (alt == 1) {
 580                         struct net_device       *net;
 581
 582                         /* Enable zlps by default for ECM conformance;
 583                          * override for musb_hdrc (avoids txdma ovhead).
 584                          */
 585                         ecm->port.is_zlp_ok = !(gadget_is_musbhdrc(cdev->gadget)
 586                                 );
 587                         ecm->port.cdc_filter = DEFAULT_FILTER;
 588                         DBG(cdev, "activate ecm\n");
 589                         net = gether_connect(&ecm->port);
 590                         if (IS_ERR(net))
 591                                 return PTR_ERR(net);
 592                 }
 593
 594                 /* NOTE this can be a minor disagreement with the ECM spec,
 595                  * which says speed notifications will "always" follow
 596                  * connection notifications.  But we allow one connect to
 597                  * follow another (if the first is in flight), and instead
 598                  * just guarantee that a speed notification is always sent.
 599                  */
 600                 ecm_notify(ecm);
 601         } else
 602                 goto fail;
 603
 604         return 0;
 605 fail:
 606         return -EINVAL;
 607 }
 608
 609 /* Because the data interface supports multiple altsettings,
 610  * this ECM function *MUST* implement a get_alt() method.
 611  */
 612 static int ecm_get_alt(struct usb_function *f, unsigned intf)
 613 {
 614         struct f_ecm            *ecm = func_to_ecm(f);
 615
 616         if (intf == ecm->ctrl_id)
 617                 return 0;
 618         return ecm->port.in_ep->driver_data ? 1 : 0;
 619 }
 620
 621 static void ecm_disable(struct usb_function *f)
 622 {
 623         struct f_ecm            *ecm = func_to_ecm(f);
 624         struct usb_composite_dev *cdev = f->config->cdev;
 625
 626         DBG(cdev, "ecm deactivated\n");
 627
 628         if (ecm->port.in_ep->driver_data)
 629                 gether_disconnect(&ecm->port);
 630
 631         if (ecm->notify->driver_data) {
 632                 usb_ep_disable(ecm->notify);
 633                 ecm->notify->driver_data = NULL;
 634                 ecm->notify->desc = NULL;
 635         }
 636 }
 637
 638 /*-------------------------------------------------------------------------*/
 639
 640 /*
 641  * Callbacks let us notify the host about connect/disconnect when the
 642  * net device is opened or closed.
 643  *
 644  * For testing, note that link states on this side include both opened
 645  * and closed variants of:
 646  *
 647  *   - disconnected/unconfigured
 648  *   - configured but inactive (data alt 0)
 649  *   - configured and active (data alt 1)
 650  *
 651  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 652  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 653  * imply the host is actually polling the notification endpoint, and
 654  * likewise that "active" doesn't imply it's actually using the data
 655  * endpoints for traffic.
 656  */
 657
 658 static void ecm_open(struct gether *geth)
 659 {
 660         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 661
 662         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 663
 664         ecm->is_open = true;
 665         ecm_notify(ecm);
 666 }
 667
 668 static void ecm_close(struct gether *geth)
 669 {
 670         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 671
 672         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 673
 674         ecm->is_open = false;
 675         ecm_notify(ecm);
 676 }
 677
 678 /*-------------------------------------------------------------------------*/
 679
 680 /* ethernet function driver setup/binding */
 681
 682 static int
 683 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 684 {
 685         struct usb_composite_dev *cdev = c->cdev;
 686         struct f_ecm            *ecm = func_to_ecm(f);
 687         int                     status;
 688         struct usb_ep           *ep;
 689
 690         /* allocate instance-specific interface IDs */
 691         status = usb_interface_id(c, f);
 692         if (status < 0)
 693                 goto fail;
 694         ecm->ctrl_id = status;
 695         ecm_iad_descriptor.bFirstInterface = status;
 696
 697         ecm_control_intf.bInterfaceNumber = status;
 698         ecm_union_desc.bMasterInterface0 = status;
 699
 700         status = usb_interface_id(c, f);
 701         if (status < 0)
 702                 goto fail;
 703         ecm->data_id = status;
 704
 705         ecm_data_nop_intf.bInterfaceNumber = status;
 706         ecm_data_intf.bInterfaceNumber = status;
 707         ecm_union_desc.bSlaveInterface0 = status;
 708
 709         status = -ENODEV;
 710
 711         /* allocate instance-specific endpoints */
 712         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 713         if (!ep)
 714                 goto fail;
 715         ecm->port.in_ep = ep;
 716         ep->driver_data = cdev; /* claim */
 717
 718         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 719         if (!ep)
 720                 goto fail;
 721         ecm->port.out_ep = ep;
 722         ep->driver_data = cdev; /* claim */
 723
 724         /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 725          * don't treat it that way.  It's simpler, and some newer CDC
 726          * profiles (wireless handsets) no longer treat it as optional.
 727          */
 728         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 729         if (!ep)
 730                 goto fail;
 731         ecm->notify = ep;
 732         ep->driver_data = cdev; /* claim */
 733
 734         status = -ENOMEM;
 735
 736         /* allocate notification request and buffer */
 737         ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 738         if (!ecm->notify_req)
 739                 goto fail;
 740         ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 741         if (!ecm->notify_req->buf)
 742                 goto fail;
 743         ecm->notify_req->context = ecm;
 744         ecm->notify_req->complete = ecm_notify_complete;
 745
 746         /* support all relevant hardware speeds... we expect that when
 747          * hardware is dual speed, all bulk-capable endpoints work at
 748          * both speeds
 749          */
 750         hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 751         hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 752         hs_ecm_notify_desc.bEndpointAddress =
 753                 fs_ecm_notify_desc.bEndpointAddress;
 754
 755         ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 756         ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 757         ss_ecm_notify_desc.bEndpointAddress =
 758                 fs_ecm_notify_desc.bEndpointAddress;
 759
 760         status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
 761                         ecm_ss_function);
 762         if (status)
 763                 goto fail;
 764
 765         /* NOTE:  all that is done without knowing or caring about
 766          * the network link ... which is unavailable to this code
 767          * until we're activated via set_alt().
 768          */
 769
 770         ecm->port.open = ecm_open;
 771         ecm->port.close = ecm_close;
 772
 773         DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 774                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 775                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 776                         ecm->port.in_ep->name, ecm->port.out_ep->name,
 777                         ecm->notify->name);
 778         return 0;
 779
 780 fail:
 781         if (ecm->notify_req) {
 782                 kfree(ecm->notify_req->buf);
 783                 usb_ep_free_request(ecm->notify, ecm->notify_req);
 784         }
 785
 786         /* we might as well release our claims on endpoints */
 787         if (ecm->notify)
 788                 ecm->notify->driver_data = NULL;
 789         if (ecm->port.out_ep)
 790                 ecm->port.out_ep->driver_data = NULL;
 791         if (ecm->port.in_ep)
 792                 ecm->port.in_ep->driver_data = NULL;
 793
 794         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 795
 796         return status;
 797 }
 798
 799 static void
 800 ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 801 {
 802         struct f_ecm            *ecm = func_to_ecm(f);
 803
 804         DBG(c->cdev, "ecm unbind\n");
 805
 806         ecm_string_defs[0].id = 0;
 807         usb_free_all_descriptors(f);
 808
 809         kfree(ecm->notify_req->buf);
 810         usb_ep_free_request(ecm->notify, ecm->notify_req);
 811         kfree(ecm);
 812 }
 813
 814 /**
 815  * ecm_bind_config - add CDC Ethernet network link to a configuration
 816  * @c: the configuration to support the network link
 817  * @ethaddr: a buffer in which the ethernet address of the host side
 818  *      side of the link was recorded
 819  * Context: single threaded during gadget setup
 820  *
 821  * Returns zero on success, else negative errno.
 822  *
 823  * Caller must have called @gether_setup().  Caller is also responsible
 824  * for calling @gether_cleanup() before module unload.
 825  */
 826 int
 827 ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
 828                 struct eth_dev *dev)
 829 {
 830         struct f_ecm    *ecm;
 831         int             status;
 832
 833         if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
 834                 return -EINVAL;
 835
 836         if (ecm_string_defs[0].id == 0) {
 837                 status = usb_string_ids_tab(c->cdev, ecm_string_defs);
 838                 if (status)
 839                         return status;
 840
 841                 ecm_control_intf.iInterface = ecm_string_defs[0].id;
 842                 ecm_data_intf.iInterface = ecm_string_defs[2].id;
 843                 ecm_desc.iMACAddress = ecm_string_defs[1].id;
 844                 ecm_iad_descriptor.iFunction = ecm_string_defs[3].id;
 845         }
 846
 847         /* allocate and initialize one new instance */
 848         ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
 849         if (!ecm)
 850                 return -ENOMEM;
 851
 852         /* export host's Ethernet address in CDC format */
 853         snprintf(ecm->ethaddr, sizeof ecm->ethaddr, "%pm", ethaddr);
 854         ecm_string_defs[1].s = ecm->ethaddr;
 855
 856         ecm->port.ioport = dev;
 857         ecm->port.cdc_filter = DEFAULT_FILTER;
 858
 859         ecm->port.func.name = "cdc_ethernet";
 860         ecm->port.func.strings = ecm_strings;
 861         /* descriptors are per-instance copies */
 862         ecm->port.func.bind = ecm_bind;
 863         ecm->port.func.unbind = ecm_unbind;
 864         ecm->port.func.set_alt = ecm_set_alt;
 865         ecm->port.func.get_alt = ecm_get_alt;
 866         ecm->port.func.setup = ecm_setup;
 867         ecm->port.func.disable = ecm_disable;
 868
 869         status = usb_add_function(c, &ecm->port.func);
 870         if (status)
 871                 kfree(ecm);
 872         return status;
 873 }