linux/drivers/usb/gadget/f_ecm.c
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   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
  41enum 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
  47struct 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
  63static 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 */
  69static 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 LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
  95#define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  96
  97
  98/* interface descriptor: */
  99
 100static struct usb_interface_descriptor ecm_control_intf = {
 101        .bLength =              sizeof ecm_control_intf,
 102        .bDescriptorType =      USB_DT_INTERFACE,
 103
 104        /* .bInterfaceNumber = DYNAMIC */
 105        /* status endpoint is optional; this could be patched later */
 106        .bNumEndpoints =        1,
 107        .bInterfaceClass =      USB_CLASS_COMM,
 108        .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 109        .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 110        /* .iInterface = DYNAMIC */
 111};
 112
 113static struct usb_cdc_header_desc ecm_header_desc = {
 114        .bLength =              sizeof ecm_header_desc,
 115        .bDescriptorType =      USB_DT_CS_INTERFACE,
 116        .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 117
 118        .bcdCDC =               cpu_to_le16(0x0110),
 119};
 120
 121static struct usb_cdc_union_desc ecm_union_desc = {
 122        .bLength =              sizeof(ecm_union_desc),
 123        .bDescriptorType =      USB_DT_CS_INTERFACE,
 124        .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 125        /* .bMasterInterface0 = DYNAMIC */
 126        /* .bSlaveInterface0 =  DYNAMIC */
 127};
 128
 129static struct usb_cdc_ether_desc ecm_desc = {
 130        .bLength =              sizeof ecm_desc,
 131        .bDescriptorType =      USB_DT_CS_INTERFACE,
 132        .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 133
 134        /* this descriptor actually adds value, surprise! */
 135        /* .iMACAddress = DYNAMIC */
 136        .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 137        .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 138        .wNumberMCFilters =     cpu_to_le16(0),
 139        .bNumberPowerFilters =  0,
 140};
 141
 142/* the default data interface has no endpoints ... */
 143
 144static struct usb_interface_descriptor ecm_data_nop_intf = {
 145        .bLength =              sizeof ecm_data_nop_intf,
 146        .bDescriptorType =      USB_DT_INTERFACE,
 147
 148        .bInterfaceNumber =     1,
 149        .bAlternateSetting =    0,
 150        .bNumEndpoints =        0,
 151        .bInterfaceClass =      USB_CLASS_CDC_DATA,
 152        .bInterfaceSubClass =   0,
 153        .bInterfaceProtocol =   0,
 154        /* .iInterface = DYNAMIC */
 155};
 156
 157/* ... but the "real" data interface has two bulk endpoints */
 158
 159static struct usb_interface_descriptor ecm_data_intf = {
 160        .bLength =              sizeof ecm_data_intf,
 161        .bDescriptorType =      USB_DT_INTERFACE,
 162
 163        .bInterfaceNumber =     1,
 164        .bAlternateSetting =    1,
 165        .bNumEndpoints =        2,
 166        .bInterfaceClass =      USB_CLASS_CDC_DATA,
 167        .bInterfaceSubClass =   0,
 168        .bInterfaceProtocol =   0,
 169        /* .iInterface = DYNAMIC */
 170};
 171
 172/* full speed support: */
 173
 174static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 175        .bLength =              USB_DT_ENDPOINT_SIZE,
 176        .bDescriptorType =      USB_DT_ENDPOINT,
 177
 178        .bEndpointAddress =     USB_DIR_IN,
 179        .bmAttributes =         USB_ENDPOINT_XFER_INT,
 180        .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 181        .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
 182};
 183
 184static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 185        .bLength =              USB_DT_ENDPOINT_SIZE,
 186        .bDescriptorType =      USB_DT_ENDPOINT,
 187
 188        .bEndpointAddress =     USB_DIR_IN,
 189        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 190};
 191
 192static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 193        .bLength =              USB_DT_ENDPOINT_SIZE,
 194        .bDescriptorType =      USB_DT_ENDPOINT,
 195
 196        .bEndpointAddress =     USB_DIR_OUT,
 197        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 198};
 199
 200static struct usb_descriptor_header *ecm_fs_function[] = {
 201        /* CDC ECM control descriptors */
 202        (struct usb_descriptor_header *) &ecm_control_intf,
 203        (struct usb_descriptor_header *) &ecm_header_desc,
 204        (struct usb_descriptor_header *) &ecm_union_desc,
 205        (struct usb_descriptor_header *) &ecm_desc,
 206
 207        /* NOTE: status endpoint might need to be removed */
 208        (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 209
 210        /* data interface, altsettings 0 and 1 */
 211        (struct usb_descriptor_header *) &ecm_data_nop_intf,
 212        (struct usb_descriptor_header *) &ecm_data_intf,
 213        (struct usb_descriptor_header *) &fs_ecm_in_desc,
 214        (struct usb_descriptor_header *) &fs_ecm_out_desc,
 215        NULL,
 216};
 217
 218/* high speed support: */
 219
 220static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 221        .bLength =              USB_DT_ENDPOINT_SIZE,
 222        .bDescriptorType =      USB_DT_ENDPOINT,
 223
 224        .bEndpointAddress =     USB_DIR_IN,
 225        .bmAttributes =         USB_ENDPOINT_XFER_INT,
 226        .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 227        .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 228};
 229
 230static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 231        .bLength =              USB_DT_ENDPOINT_SIZE,
 232        .bDescriptorType =      USB_DT_ENDPOINT,
 233
 234        .bEndpointAddress =     USB_DIR_IN,
 235        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 236        .wMaxPacketSize =       cpu_to_le16(512),
 237};
 238
 239static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 240        .bLength =              USB_DT_ENDPOINT_SIZE,
 241        .bDescriptorType =      USB_DT_ENDPOINT,
 242
 243        .bEndpointAddress =     USB_DIR_OUT,
 244        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 245        .wMaxPacketSize =       cpu_to_le16(512),
 246};
 247
 248static struct usb_descriptor_header *ecm_hs_function[] = {
 249        /* CDC ECM control descriptors */
 250        (struct usb_descriptor_header *) &ecm_control_intf,
 251        (struct usb_descriptor_header *) &ecm_header_desc,
 252        (struct usb_descriptor_header *) &ecm_union_desc,
 253        (struct usb_descriptor_header *) &ecm_desc,
 254
 255        /* NOTE: status endpoint might need to be removed */
 256        (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 257
 258        /* data interface, altsettings 0 and 1 */
 259        (struct usb_descriptor_header *) &ecm_data_nop_intf,
 260        (struct usb_descriptor_header *) &ecm_data_intf,
 261        (struct usb_descriptor_header *) &hs_ecm_in_desc,
 262        (struct usb_descriptor_header *) &hs_ecm_out_desc,
 263        NULL,
 264};
 265
 266/* super speed support: */
 267
 268static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 269        .bLength =              USB_DT_ENDPOINT_SIZE,
 270        .bDescriptorType =      USB_DT_ENDPOINT,
 271
 272        .bEndpointAddress =     USB_DIR_IN,
 273        .bmAttributes =         USB_ENDPOINT_XFER_INT,
 274        .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 275        .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 276};
 277
 278static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 279        .bLength =              sizeof ss_ecm_intr_comp_desc,
 280        .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 281
 282        /* the following 3 values can be tweaked if necessary */
 283        /* .bMaxBurst =         0, */
 284        /* .bmAttributes =      0, */
 285        .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 286};
 287
 288static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 289        .bLength =              USB_DT_ENDPOINT_SIZE,
 290        .bDescriptorType =      USB_DT_ENDPOINT,
 291
 292        .bEndpointAddress =     USB_DIR_IN,
 293        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 294        .wMaxPacketSize =       cpu_to_le16(1024),
 295};
 296
 297static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 298        .bLength =              USB_DT_ENDPOINT_SIZE,
 299        .bDescriptorType =      USB_DT_ENDPOINT,
 300
 301        .bEndpointAddress =     USB_DIR_OUT,
 302        .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 303        .wMaxPacketSize =       cpu_to_le16(1024),
 304};
 305
 306static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 307        .bLength =              sizeof ss_ecm_bulk_comp_desc,
 308        .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 309
 310        /* the following 2 values can be tweaked if necessary */
 311        /* .bMaxBurst =         0, */
 312        /* .bmAttributes =      0, */
 313};
 314
 315static struct usb_descriptor_header *ecm_ss_function[] = {
 316        /* CDC ECM control descriptors */
 317        (struct usb_descriptor_header *) &ecm_control_intf,
 318        (struct usb_descriptor_header *) &ecm_header_desc,
 319        (struct usb_descriptor_header *) &ecm_union_desc,
 320        (struct usb_descriptor_header *) &ecm_desc,
 321
 322        /* NOTE: status endpoint might need to be removed */
 323        (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 324        (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 325
 326        /* data interface, altsettings 0 and 1 */
 327        (struct usb_descriptor_header *) &ecm_data_nop_intf,
 328        (struct usb_descriptor_header *) &ecm_data_intf,
 329        (struct usb_descriptor_header *) &ss_ecm_in_desc,
 330        (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 331        (struct usb_descriptor_header *) &ss_ecm_out_desc,
 332        (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 333        NULL,
 334};
 335
 336/* string descriptors: */
 337
 338static struct usb_string ecm_string_defs[] = {
 339        [0].s = "CDC Ethernet Control Model (ECM)",
 340        [1].s = NULL /* DYNAMIC */,
 341        [2].s = "CDC Ethernet Data",
 342        {  } /* end of list */
 343};
 344
 345static struct usb_gadget_strings ecm_string_table = {
 346        .language =             0x0409, /* en-us */
 347        .strings =              ecm_string_defs,
 348};
 349
 350static struct usb_gadget_strings *ecm_strings[] = {
 351        &ecm_string_table,
 352        NULL,
 353};
 354
 355/*-------------------------------------------------------------------------*/
 356
 357static void ecm_do_notify(struct f_ecm *ecm)
 358{
 359        struct usb_request              *req = ecm->notify_req;
 360        struct usb_cdc_notification     *event;
 361        struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 362        __le32                          *data;
 363        int                             status;
 364
 365        /* notification already in flight? */
 366        if (!req)
 367                return;
 368
 369        event = req->buf;
 370        switch (ecm->notify_state) {
 371        case ECM_NOTIFY_NONE:
 372                return;
 373
 374        case ECM_NOTIFY_CONNECT:
 375                event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 376                if (ecm->is_open)
 377                        event->wValue = cpu_to_le16(1);
 378                else
 379                        event->wValue = cpu_to_le16(0);
 380                event->wLength = 0;
 381                req->length = sizeof *event;
 382
 383                DBG(cdev, "notify connect %s\n",
 384                                ecm->is_open ? "true" : "false");
 385                ecm->notify_state = ECM_NOTIFY_SPEED;
 386                break;
 387
 388        case ECM_NOTIFY_SPEED:
 389                event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 390                event->wValue = cpu_to_le16(0);
 391                event->wLength = cpu_to_le16(8);
 392                req->length = ECM_STATUS_BYTECOUNT;
 393
 394                /* SPEED_CHANGE data is up/down speeds in bits/sec */
 395                data = req->buf + sizeof *event;
 396                data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 397                data[1] = data[0];
 398
 399                DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 400                ecm->notify_state = ECM_NOTIFY_NONE;
 401                break;
 402        }
 403        event->bmRequestType = 0xA1;
 404        event->wIndex = cpu_to_le16(ecm->ctrl_id);
 405
 406        ecm->notify_req = NULL;
 407        status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 408        if (status < 0) {
 409                ecm->notify_req = req;
 410                DBG(cdev, "notify --> %d\n", status);
 411        }
 412}
 413
 414static void ecm_notify(struct f_ecm *ecm)
 415{
 416        /* NOTE on most versions of Linux, host side cdc-ethernet
 417         * won't listen for notifications until its netdevice opens.
 418         * The first notification then sits in the FIFO for a long
 419         * time, and the second one is queued.
 420         */
 421        ecm->notify_state = ECM_NOTIFY_CONNECT;
 422        ecm_do_notify(ecm);
 423}
 424
 425static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 426{
 427        struct f_ecm                    *ecm = req->context;
 428        struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 429        struct usb_cdc_notification     *event = req->buf;
 430
 431        switch (req->status) {
 432        case 0:
 433                /* no fault */
 434                break;
 435        case -ECONNRESET:
 436        case -ESHUTDOWN:
 437                ecm->notify_state = ECM_NOTIFY_NONE;
 438                break;
 439        default:
 440                DBG(cdev, "event %02x --> %d\n",
 441                        event->bNotificationType, req->status);
 442                break;
 443        }
 444        ecm->notify_req = req;
 445        ecm_do_notify(ecm);
 446}
 447
 448static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 449{
 450        struct f_ecm            *ecm = func_to_ecm(f);
 451        struct usb_composite_dev *cdev = f->config->cdev;
 452        struct usb_request      *req = cdev->req;
 453        int                     value = -EOPNOTSUPP;
 454        u16                     w_index = le16_to_cpu(ctrl->wIndex);
 455        u16                     w_value = le16_to_cpu(ctrl->wValue);
 456        u16                     w_length = le16_to_cpu(ctrl->wLength);
 457
 458        /* composite driver infrastructure handles everything except
 459         * CDC class messages; interface activation uses set_alt().
 460         */
 461        switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 462        case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 463                        | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 464                /* see 6.2.30: no data, wIndex = interface,
 465                 * wValue = packet filter bitmap
 466                 */
 467                if (w_length != 0 || w_index != ecm->ctrl_id)
 468                        goto invalid;
 469                DBG(cdev, "packet filter %02x\n", w_value);
 470                /* REVISIT locking of cdc_filter.  This assumes the UDC
 471                 * driver won't have a concurrent packet TX irq running on
 472                 * another CPU; or that if it does, this write is atomic...
 473                 */
 474                ecm->port.cdc_filter = w_value;
 475                value = 0;
 476                break;
 477
 478        /* and optionally:
 479         * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 480         * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 481         * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 482         * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 483         * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 484         * case USB_CDC_GET_ETHERNET_STATISTIC:
 485         */
 486
 487        default:
 488invalid:
 489                DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 490                        ctrl->bRequestType, ctrl->bRequest,
 491                        w_value, w_index, w_length);
 492        }
 493
 494        /* respond with data transfer or status phase? */
 495        if (value >= 0) {
 496                DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 497                        ctrl->bRequestType, ctrl->bRequest,
 498                        w_value, w_index, w_length);
 499                req->zero = 0;
 500                req->length = value;
 501                value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 502                if (value < 0)
 503                        ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 504                                        ctrl->bRequestType, ctrl->bRequest,
 505                                        value);
 506        }
 507
 508        /* device either stalls (value < 0) or reports success */
 509        return value;
 510}
 511
 512
 513static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 514{
 515        struct f_ecm            *ecm = func_to_ecm(f);
 516        struct usb_composite_dev *cdev = f->config->cdev;
 517
 518        /* Control interface has only altsetting 0 */
 519        if (intf == ecm->ctrl_id) {
 520                if (alt != 0)
 521                        goto fail;
 522
 523                if (ecm->notify->driver_data) {
 524                        VDBG(cdev, "reset ecm control %d\n", intf);
 525                        usb_ep_disable(ecm->notify);
 526                }
 527                if (!(ecm->notify->desc)) {
 528                        VDBG(cdev, "init ecm ctrl %d\n", intf);
 529                        if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 530                                goto fail;
 531                }
 532                usb_ep_enable(ecm->notify);
 533                ecm->notify->driver_data = ecm;
 534
 535        /* Data interface has two altsettings, 0 and 1 */
 536        } else if (intf == ecm->data_id) {
 537                if (alt > 1)
 538                        goto fail;
 539
 540                if (ecm->port.in_ep->driver_data) {
 541                        DBG(cdev, "reset ecm\n");
 542                        gether_disconnect(&ecm->port);
 543                }
 544
 545                if (!ecm->port.in_ep->desc ||
 546                    !ecm->port.out_ep->desc) {
 547                        DBG(cdev, "init ecm\n");
 548                        if (config_ep_by_speed(cdev->gadget, f,
 549                                               ecm->port.in_ep) ||
 550                            config_ep_by_speed(cdev->gadget, f,
 551                                               ecm->port.out_ep)) {
 552                                ecm->port.in_ep->desc = NULL;
 553                                ecm->port.out_ep->desc = NULL;
 554                                goto fail;
 555                        }
 556                }
 557
 558                /* CDC Ethernet only sends data in non-default altsettings.
 559                 * Changing altsettings resets filters, statistics, etc.
 560                 */
 561                if (alt == 1) {
 562                        struct net_device       *net;
 563
 564                        /* Enable zlps by default for ECM conformance;
 565                         * override for musb_hdrc (avoids txdma ovhead).
 566                         */
 567                        ecm->port.is_zlp_ok = !(gadget_is_musbhdrc(cdev->gadget)
 568                                );
 569                        ecm->port.cdc_filter = DEFAULT_FILTER;
 570                        DBG(cdev, "activate ecm\n");
 571                        net = gether_connect(&ecm->port);
 572                        if (IS_ERR(net))
 573                                return PTR_ERR(net);
 574                }
 575
 576                /* NOTE this can be a minor disagreement with the ECM spec,
 577                 * which says speed notifications will "always" follow
 578                 * connection notifications.  But we allow one connect to
 579                 * follow another (if the first is in flight), and instead
 580                 * just guarantee that a speed notification is always sent.
 581                 */
 582                ecm_notify(ecm);
 583        } else
 584                goto fail;
 585
 586        return 0;
 587fail:
 588        return -EINVAL;
 589}
 590
 591/* Because the data interface supports multiple altsettings,
 592 * this ECM function *MUST* implement a get_alt() method.
 593 */
 594static int ecm_get_alt(struct usb_function *f, unsigned intf)
 595{
 596        struct f_ecm            *ecm = func_to_ecm(f);
 597
 598        if (intf == ecm->ctrl_id)
 599                return 0;
 600        return ecm->port.in_ep->driver_data ? 1 : 0;
 601}
 602
 603static void ecm_disable(struct usb_function *f)
 604{
 605        struct f_ecm            *ecm = func_to_ecm(f);
 606        struct usb_composite_dev *cdev = f->config->cdev;
 607
 608        DBG(cdev, "ecm deactivated\n");
 609
 610        if (ecm->port.in_ep->driver_data)
 611                gether_disconnect(&ecm->port);
 612
 613        if (ecm->notify->driver_data) {
 614                usb_ep_disable(ecm->notify);
 615                ecm->notify->driver_data = NULL;
 616                ecm->notify->desc = NULL;
 617        }
 618}
 619
 620/*-------------------------------------------------------------------------*/
 621
 622/*
 623 * Callbacks let us notify the host about connect/disconnect when the
 624 * net device is opened or closed.
 625 *
 626 * For testing, note that link states on this side include both opened
 627 * and closed variants of:
 628 *
 629 *   - disconnected/unconfigured
 630 *   - configured but inactive (data alt 0)
 631 *   - configured and active (data alt 1)
 632 *
 633 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 634 * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 635 * imply the host is actually polling the notification endpoint, and
 636 * likewise that "active" doesn't imply it's actually using the data
 637 * endpoints for traffic.
 638 */
 639
 640static void ecm_open(struct gether *geth)
 641{
 642        struct f_ecm            *ecm = func_to_ecm(&geth->func);
 643
 644        DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 645
 646        ecm->is_open = true;
 647        ecm_notify(ecm);
 648}
 649
 650static void ecm_close(struct gether *geth)
 651{
 652        struct f_ecm            *ecm = func_to_ecm(&geth->func);
 653
 654        DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 655
 656        ecm->is_open = false;
 657        ecm_notify(ecm);
 658}
 659
 660/*-------------------------------------------------------------------------*/
 661
 662/* ethernet function driver setup/binding */
 663
 664static int
 665ecm_bind(struct usb_configuration *c, struct usb_function *f)
 666{
 667        struct usb_composite_dev *cdev = c->cdev;
 668        struct f_ecm            *ecm = func_to_ecm(f);
 669        int                     status;
 670        struct usb_ep           *ep;
 671
 672        /* allocate instance-specific interface IDs */
 673        status = usb_interface_id(c, f);
 674        if (status < 0)
 675                goto fail;
 676        ecm->ctrl_id = status;
 677
 678        ecm_control_intf.bInterfaceNumber = status;
 679        ecm_union_desc.bMasterInterface0 = status;
 680
 681        status = usb_interface_id(c, f);
 682        if (status < 0)
 683                goto fail;
 684        ecm->data_id = status;
 685
 686        ecm_data_nop_intf.bInterfaceNumber = status;
 687        ecm_data_intf.bInterfaceNumber = status;
 688        ecm_union_desc.bSlaveInterface0 = status;
 689
 690        status = -ENODEV;
 691
 692        /* allocate instance-specific endpoints */
 693        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 694        if (!ep)
 695                goto fail;
 696        ecm->port.in_ep = ep;
 697        ep->driver_data = cdev; /* claim */
 698
 699        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 700        if (!ep)
 701                goto fail;
 702        ecm->port.out_ep = ep;
 703        ep->driver_data = cdev; /* claim */
 704
 705        /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 706         * don't treat it that way.  It's simpler, and some newer CDC
 707         * profiles (wireless handsets) no longer treat it as optional.
 708         */
 709        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 710        if (!ep)
 711                goto fail;
 712        ecm->notify = ep;
 713        ep->driver_data = cdev; /* claim */
 714
 715        status = -ENOMEM;
 716
 717        /* allocate notification request and buffer */
 718        ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 719        if (!ecm->notify_req)
 720                goto fail;
 721        ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 722        if (!ecm->notify_req->buf)
 723                goto fail;
 724        ecm->notify_req->context = ecm;
 725        ecm->notify_req->complete = ecm_notify_complete;
 726
 727        /* copy descriptors, and track endpoint copies */
 728        f->descriptors = usb_copy_descriptors(ecm_fs_function);
 729        if (!f->descriptors)
 730                goto fail;
 731
 732        /* support all relevant hardware speeds... we expect that when
 733         * hardware is dual speed, all bulk-capable endpoints work at
 734         * both speeds
 735         */
 736        if (gadget_is_dualspeed(c->cdev->gadget)) {
 737                hs_ecm_in_desc.bEndpointAddress =
 738                                fs_ecm_in_desc.bEndpointAddress;
 739                hs_ecm_out_desc.bEndpointAddress =
 740                                fs_ecm_out_desc.bEndpointAddress;
 741                hs_ecm_notify_desc.bEndpointAddress =
 742                                fs_ecm_notify_desc.bEndpointAddress;
 743
 744                /* copy descriptors, and track endpoint copies */
 745                f->hs_descriptors = usb_copy_descriptors(ecm_hs_function);
 746                if (!f->hs_descriptors)
 747                        goto fail;
 748        }
 749
 750        if (gadget_is_superspeed(c->cdev->gadget)) {
 751                ss_ecm_in_desc.bEndpointAddress =
 752                                fs_ecm_in_desc.bEndpointAddress;
 753                ss_ecm_out_desc.bEndpointAddress =
 754                                fs_ecm_out_desc.bEndpointAddress;
 755                ss_ecm_notify_desc.bEndpointAddress =
 756                                fs_ecm_notify_desc.bEndpointAddress;
 757
 758                /* copy descriptors, and track endpoint copies */
 759                f->ss_descriptors = usb_copy_descriptors(ecm_ss_function);
 760                if (!f->ss_descriptors)
 761                        goto fail;
 762        }
 763
 764        /* NOTE:  all that is done without knowing or caring about
 765         * the network link ... which is unavailable to this code
 766         * until we're activated via set_alt().
 767         */
 768
 769        ecm->port.open = ecm_open;
 770        ecm->port.close = ecm_close;
 771
 772        DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 773                        gadget_is_superspeed(c->cdev->gadget) ? "super" :
 774                        gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 775                        ecm->port.in_ep->name, ecm->port.out_ep->name,
 776                        ecm->notify->name);
 777        return 0;
 778
 779fail:
 780        if (f->descriptors)
 781                usb_free_descriptors(f->descriptors);
 782        if (f->hs_descriptors)
 783                usb_free_descriptors(f->hs_descriptors);
 784
 785        if (ecm->notify_req) {
 786                kfree(ecm->notify_req->buf);
 787                usb_ep_free_request(ecm->notify, ecm->notify_req);
 788        }
 789
 790        /* we might as well release our claims on endpoints */
 791        if (ecm->notify)
 792                ecm->notify->driver_data = NULL;
 793        if (ecm->port.out_ep->desc)
 794                ecm->port.out_ep->driver_data = NULL;
 795        if (ecm->port.in_ep->desc)
 796                ecm->port.in_ep->driver_data = NULL;
 797
 798        ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 799
 800        return status;
 801}
 802
 803static void
 804ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 805{
 806        struct f_ecm            *ecm = func_to_ecm(f);
 807
 808        DBG(c->cdev, "ecm unbind\n");
 809
 810        if (gadget_is_superspeed(c->cdev->gadget))
 811                usb_free_descriptors(f->ss_descriptors);
 812        if (gadget_is_dualspeed(c->cdev->gadget))
 813                usb_free_descriptors(f->hs_descriptors);
 814        usb_free_descriptors(f->descriptors);
 815
 816        kfree(ecm->notify_req->buf);
 817        usb_ep_free_request(ecm->notify, ecm->notify_req);
 818
 819        ecm_string_defs[1].s = NULL;
 820        kfree(ecm);
 821}
 822
 823/**
 824 * ecm_bind_config - add CDC Ethernet network link to a configuration
 825 * @c: the configuration to support the network link
 826 * @ethaddr: a buffer in which the ethernet address of the host side
 827 *      side of the link was recorded
 828 * Context: single threaded during gadget setup
 829 *
 830 * Returns zero on success, else negative errno.
 831 *
 832 * Caller must have called @gether_setup().  Caller is also responsible
 833 * for calling @gether_cleanup() before module unload.
 834 */
 835int
 836ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 837{
 838        struct f_ecm    *ecm;
 839        int             status;
 840
 841        if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
 842                return -EINVAL;
 843
 844        /* maybe allocate device-global string IDs */
 845        if (ecm_string_defs[0].id == 0) {
 846
 847                /* control interface label */
 848                status = usb_string_id(c->cdev);
 849                if (status < 0)
 850                        return status;
 851                ecm_string_defs[0].id = status;
 852                ecm_control_intf.iInterface = status;
 853
 854                /* data interface label */
 855                status = usb_string_id(c->cdev);
 856                if (status < 0)
 857                        return status;
 858                ecm_string_defs[2].id = status;
 859                ecm_data_intf.iInterface = status;
 860
 861                /* MAC address */
 862                status = usb_string_id(c->cdev);
 863                if (status < 0)
 864                        return status;
 865                ecm_string_defs[1].id = status;
 866                ecm_desc.iMACAddress = status;
 867        }
 868
 869        /* allocate and initialize one new instance */
 870        ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
 871        if (!ecm)
 872                return -ENOMEM;
 873
 874        /* export host's Ethernet address in CDC format */
 875        snprintf(ecm->ethaddr, sizeof ecm->ethaddr,
 876                "%02X%02X%02X%02X%02X%02X",
 877                ethaddr[0], ethaddr[1], ethaddr[2],
 878                ethaddr[3], ethaddr[4], ethaddr[5]);
 879        ecm_string_defs[1].s = ecm->ethaddr;
 880
 881        ecm->port.cdc_filter = DEFAULT_FILTER;
 882
 883        ecm->port.func.name = "cdc_ethernet";
 884        ecm->port.func.strings = ecm_strings;
 885        /* descriptors are per-instance copies */
 886        ecm->port.func.bind = ecm_bind;
 887        ecm->port.func.unbind = ecm_unbind;
 888        ecm->port.func.set_alt = ecm_set_alt;
 889        ecm->port.func.get_alt = ecm_get_alt;
 890        ecm->port.func.setup = ecm_setup;
 891        ecm->port.func.disable = ecm_disable;
 892
 893        status = usb_add_function(c, &ecm->port.func);
 894        if (status) {
 895                ecm_string_defs[1].s = NULL;
 896                kfree(ecm);
 897        }
 898        return status;
 899}
 900