linux/drivers/usb/gadget/function/f_ecm.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * f_ecm.c -- USB CDC Ethernet (ECM) link function driver
   4 *
   5 * Copyright (C) 2003-2005,2008 David Brownell
   6 * Copyright (C) 2008 Nokia Corporation
   7 */
   8
   9/* #define VERBOSE_DEBUG */
  10
  11#include <linux/slab.h>
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/device.h>
  15#include <linux/etherdevice.h>
  16
  17#include "u_ether.h"
  18#include "u_ether_configfs.h"
  19#include "u_ecm.h"
  20
  21
  22/*
  23 * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  24 * Ethernet link.  The data transfer model is simple (packets sent and
  25 * received over bulk endpoints using normal short packet termination),
  26 * and the control model exposes various data and optional notifications.
  27 *
  28 * ECM is well standardized and (except for Microsoft) supported by most
  29 * operating systems with USB host support.  It's the preferred interop
  30 * solution for Ethernet over USB, at least for firmware based solutions.
  31 * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  32 * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  33 *
  34 * Note that ECM requires the use of "alternate settings" for its data
  35 * interface.  This means that the set_alt() method has real work to do,
  36 * and also means that a get_alt() method is required.
  37 */
  38
  39
  40enum ecm_notify_state {
  41        ECM_NOTIFY_NONE,                /* don't notify */
  42        ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  43        ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  44};
  45
  46struct f_ecm {
  47        struct gether                   port;
  48        u8                              ctrl_id, data_id;
  49
  50        char                            ethaddr[14];
  51
  52        struct usb_ep                   *notify;
  53        struct usb_request              *notify_req;
  54        u8                              notify_state;
  55        atomic_t                        notify_count;
  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 ECM_STATUS_INTERVAL_MS          32
  95#define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  96
  97
  98/* interface descriptor: */
  99
 100static struct usb_interface_assoc_descriptor
 101ecm_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
 114static 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
 127static 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
 135static 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
 143static 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
 158static 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
 173static 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
 188static 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
 198static 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
 206static 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
 214static 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
 235static 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
 245static 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
 254static 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
 263static 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
 284static 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
 294static 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
 304static 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
 313static 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
 322static 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
 331static 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
 355static 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
 363static struct usb_gadget_strings ecm_string_table = {
 364        .language =             0x0409, /* en-us */
 365        .strings =              ecm_string_defs,
 366};
 367
 368static struct usb_gadget_strings *ecm_strings[] = {
 369        &ecm_string_table,
 370        NULL,
 371};
 372
 373/*-------------------------------------------------------------------------*/
 374
 375static 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 (atomic_read(&ecm->notify_count))
 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        atomic_inc(&ecm->notify_count);
 425        status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 426        if (status < 0) {
 427                atomic_dec(&ecm->notify_count);
 428                DBG(cdev, "notify --> %d\n", status);
 429        }
 430}
 431
 432static 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
 443static 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                atomic_dec(&ecm->notify_count);
 453                break;
 454        case -ECONNRESET:
 455        case -ESHUTDOWN:
 456                atomic_set(&ecm->notify_count, 0);
 457                ecm->notify_state = ECM_NOTIFY_NONE;
 458                break;
 459        default:
 460                DBG(cdev, "event %02x --> %d\n",
 461                        event->bNotificationType, req->status);
 462                atomic_dec(&ecm->notify_count);
 463                break;
 464        }
 465        ecm_do_notify(ecm);
 466}
 467
 468static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 469{
 470        struct f_ecm            *ecm = func_to_ecm(f);
 471        struct usb_composite_dev *cdev = f->config->cdev;
 472        struct usb_request      *req = cdev->req;
 473        int                     value = -EOPNOTSUPP;
 474        u16                     w_index = le16_to_cpu(ctrl->wIndex);
 475        u16                     w_value = le16_to_cpu(ctrl->wValue);
 476        u16                     w_length = le16_to_cpu(ctrl->wLength);
 477
 478        /* composite driver infrastructure handles everything except
 479         * CDC class messages; interface activation uses set_alt().
 480         */
 481        switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 482        case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 483                        | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 484                /* see 6.2.30: no data, wIndex = interface,
 485                 * wValue = packet filter bitmap
 486                 */
 487                if (w_length != 0 || w_index != ecm->ctrl_id)
 488                        goto invalid;
 489                DBG(cdev, "packet filter %02x\n", w_value);
 490                /* REVISIT locking of cdc_filter.  This assumes the UDC
 491                 * driver won't have a concurrent packet TX irq running on
 492                 * another CPU; or that if it does, this write is atomic...
 493                 */
 494                ecm->port.cdc_filter = w_value;
 495                value = 0;
 496                break;
 497
 498        /* and optionally:
 499         * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 500         * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 501         * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 502         * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 503         * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 504         * case USB_CDC_GET_ETHERNET_STATISTIC:
 505         */
 506
 507        default:
 508invalid:
 509                DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 510                        ctrl->bRequestType, ctrl->bRequest,
 511                        w_value, w_index, w_length);
 512        }
 513
 514        /* respond with data transfer or status phase? */
 515        if (value >= 0) {
 516                DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 517                        ctrl->bRequestType, ctrl->bRequest,
 518                        w_value, w_index, w_length);
 519                req->zero = 0;
 520                req->length = value;
 521                value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 522                if (value < 0)
 523                        ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 524                                        ctrl->bRequestType, ctrl->bRequest,
 525                                        value);
 526        }
 527
 528        /* device either stalls (value < 0) or reports success */
 529        return value;
 530}
 531
 532
 533static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 534{
 535        struct f_ecm            *ecm = func_to_ecm(f);
 536        struct usb_composite_dev *cdev = f->config->cdev;
 537
 538        /* Control interface has only altsetting 0 */
 539        if (intf == ecm->ctrl_id) {
 540                if (alt != 0)
 541                        goto fail;
 542
 543                VDBG(cdev, "reset ecm control %d\n", intf);
 544                usb_ep_disable(ecm->notify);
 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
 552        /* Data interface has two altsettings, 0 and 1 */
 553        } else if (intf == ecm->data_id) {
 554                if (alt > 1)
 555                        goto fail;
 556
 557                if (ecm->port.in_ep->enabled) {
 558                        DBG(cdev, "reset ecm\n");
 559                        gether_disconnect(&ecm->port);
 560                }
 561
 562                if (!ecm->port.in_ep->desc ||
 563                    !ecm->port.out_ep->desc) {
 564                        DBG(cdev, "init ecm\n");
 565                        if (config_ep_by_speed(cdev->gadget, f,
 566                                               ecm->port.in_ep) ||
 567                            config_ep_by_speed(cdev->gadget, f,
 568                                               ecm->port.out_ep)) {
 569                                ecm->port.in_ep->desc = NULL;
 570                                ecm->port.out_ep->desc = NULL;
 571                                goto fail;
 572                        }
 573                }
 574
 575                /* CDC Ethernet only sends data in non-default altsettings.
 576                 * Changing altsettings resets filters, statistics, etc.
 577                 */
 578                if (alt == 1) {
 579                        struct net_device       *net;
 580
 581                        /* Enable zlps by default for ECM conformance;
 582                         * override for musb_hdrc (avoids txdma ovhead).
 583                         */
 584                        ecm->port.is_zlp_ok =
 585                                gadget_is_zlp_supported(cdev->gadget);
 586                        ecm->port.cdc_filter = DEFAULT_FILTER;
 587                        DBG(cdev, "activate ecm\n");
 588                        net = gether_connect(&ecm->port);
 589                        if (IS_ERR(net))
 590                                return PTR_ERR(net);
 591                }
 592
 593                /* NOTE this can be a minor disagreement with the ECM spec,
 594                 * which says speed notifications will "always" follow
 595                 * connection notifications.  But we allow one connect to
 596                 * follow another (if the first is in flight), and instead
 597                 * just guarantee that a speed notification is always sent.
 598                 */
 599                ecm_notify(ecm);
 600        } else
 601                goto fail;
 602
 603        return 0;
 604fail:
 605        return -EINVAL;
 606}
 607
 608/* Because the data interface supports multiple altsettings,
 609 * this ECM function *MUST* implement a get_alt() method.
 610 */
 611static int ecm_get_alt(struct usb_function *f, unsigned intf)
 612{
 613        struct f_ecm            *ecm = func_to_ecm(f);
 614
 615        if (intf == ecm->ctrl_id)
 616                return 0;
 617        return ecm->port.in_ep->enabled ? 1 : 0;
 618}
 619
 620static void ecm_disable(struct usb_function *f)
 621{
 622        struct f_ecm            *ecm = func_to_ecm(f);
 623        struct usb_composite_dev *cdev = f->config->cdev;
 624
 625        DBG(cdev, "ecm deactivated\n");
 626
 627        if (ecm->port.in_ep->enabled) {
 628                gether_disconnect(&ecm->port);
 629        } else {
 630                ecm->port.in_ep->desc = NULL;
 631                ecm->port.out_ep->desc = NULL;
 632        }
 633
 634        usb_ep_disable(ecm->notify);
 635        ecm->notify->desc = NULL;
 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
 658static 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
 668static 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
 682static int
 683ecm_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        struct usb_string       *us;
 688        int                     status;
 689        struct usb_ep           *ep;
 690
 691        struct f_ecm_opts       *ecm_opts;
 692
 693        if (!can_support_ecm(cdev->gadget))
 694                return -EINVAL;
 695
 696        ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 697
 698        /*
 699         * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 700         * configurations are bound in sequence with list_for_each_entry,
 701         * in each configuration its functions are bound in sequence
 702         * with list_for_each_entry, so we assume no race condition
 703         * with regard to ecm_opts->bound access
 704         */
 705        if (!ecm_opts->bound) {
 706                mutex_lock(&ecm_opts->lock);
 707                gether_set_gadget(ecm_opts->net, cdev->gadget);
 708                status = gether_register_netdev(ecm_opts->net);
 709                mutex_unlock(&ecm_opts->lock);
 710                if (status)
 711                        return status;
 712                ecm_opts->bound = true;
 713        }
 714
 715        ecm_string_defs[1].s = ecm->ethaddr;
 716
 717        us = usb_gstrings_attach(cdev, ecm_strings,
 718                                 ARRAY_SIZE(ecm_string_defs));
 719        if (IS_ERR(us))
 720                return PTR_ERR(us);
 721        ecm_control_intf.iInterface = us[0].id;
 722        ecm_data_intf.iInterface = us[2].id;
 723        ecm_desc.iMACAddress = us[1].id;
 724        ecm_iad_descriptor.iFunction = us[3].id;
 725
 726        /* allocate instance-specific interface IDs */
 727        status = usb_interface_id(c, f);
 728        if (status < 0)
 729                goto fail;
 730        ecm->ctrl_id = status;
 731        ecm_iad_descriptor.bFirstInterface = status;
 732
 733        ecm_control_intf.bInterfaceNumber = status;
 734        ecm_union_desc.bMasterInterface0 = status;
 735
 736        status = usb_interface_id(c, f);
 737        if (status < 0)
 738                goto fail;
 739        ecm->data_id = status;
 740
 741        ecm_data_nop_intf.bInterfaceNumber = status;
 742        ecm_data_intf.bInterfaceNumber = status;
 743        ecm_union_desc.bSlaveInterface0 = status;
 744
 745        status = -ENODEV;
 746
 747        /* allocate instance-specific endpoints */
 748        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 749        if (!ep)
 750                goto fail;
 751        ecm->port.in_ep = ep;
 752
 753        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 754        if (!ep)
 755                goto fail;
 756        ecm->port.out_ep = ep;
 757
 758        /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 759         * don't treat it that way.  It's simpler, and some newer CDC
 760         * profiles (wireless handsets) no longer treat it as optional.
 761         */
 762        ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 763        if (!ep)
 764                goto fail;
 765        ecm->notify = ep;
 766
 767        status = -ENOMEM;
 768
 769        /* allocate notification request and buffer */
 770        ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 771        if (!ecm->notify_req)
 772                goto fail;
 773        ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 774        if (!ecm->notify_req->buf)
 775                goto fail;
 776        ecm->notify_req->context = ecm;
 777        ecm->notify_req->complete = ecm_notify_complete;
 778
 779        /* support all relevant hardware speeds... we expect that when
 780         * hardware is dual speed, all bulk-capable endpoints work at
 781         * both speeds
 782         */
 783        hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 784        hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 785        hs_ecm_notify_desc.bEndpointAddress =
 786                fs_ecm_notify_desc.bEndpointAddress;
 787
 788        ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 789        ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 790        ss_ecm_notify_desc.bEndpointAddress =
 791                fs_ecm_notify_desc.bEndpointAddress;
 792
 793        status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
 794                        ecm_ss_function, ecm_ss_function);
 795        if (status)
 796                goto fail;
 797
 798        /* NOTE:  all that is done without knowing or caring about
 799         * the network link ... which is unavailable to this code
 800         * until we're activated via set_alt().
 801         */
 802
 803        ecm->port.open = ecm_open;
 804        ecm->port.close = ecm_close;
 805
 806        DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 807                        gadget_is_superspeed(c->cdev->gadget) ? "super" :
 808                        gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 809                        ecm->port.in_ep->name, ecm->port.out_ep->name,
 810                        ecm->notify->name);
 811        return 0;
 812
 813fail:
 814        if (ecm->notify_req) {
 815                kfree(ecm->notify_req->buf);
 816                usb_ep_free_request(ecm->notify, ecm->notify_req);
 817        }
 818
 819        ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 820
 821        return status;
 822}
 823
 824static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
 825{
 826        return container_of(to_config_group(item), struct f_ecm_opts,
 827                            func_inst.group);
 828}
 829
 830/* f_ecm_item_ops */
 831USB_ETHERNET_CONFIGFS_ITEM(ecm);
 832
 833/* f_ecm_opts_dev_addr */
 834USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
 835
 836/* f_ecm_opts_host_addr */
 837USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
 838
 839/* f_ecm_opts_qmult */
 840USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
 841
 842/* f_ecm_opts_ifname */
 843USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
 844
 845static struct configfs_attribute *ecm_attrs[] = {
 846        &ecm_opts_attr_dev_addr,
 847        &ecm_opts_attr_host_addr,
 848        &ecm_opts_attr_qmult,
 849        &ecm_opts_attr_ifname,
 850        NULL,
 851};
 852
 853static const struct config_item_type ecm_func_type = {
 854        .ct_item_ops    = &ecm_item_ops,
 855        .ct_attrs       = ecm_attrs,
 856        .ct_owner       = THIS_MODULE,
 857};
 858
 859static void ecm_free_inst(struct usb_function_instance *f)
 860{
 861        struct f_ecm_opts *opts;
 862
 863        opts = container_of(f, struct f_ecm_opts, func_inst);
 864        if (opts->bound)
 865                gether_cleanup(netdev_priv(opts->net));
 866        else
 867                free_netdev(opts->net);
 868        kfree(opts);
 869}
 870
 871static struct usb_function_instance *ecm_alloc_inst(void)
 872{
 873        struct f_ecm_opts *opts;
 874
 875        opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 876        if (!opts)
 877                return ERR_PTR(-ENOMEM);
 878        mutex_init(&opts->lock);
 879        opts->func_inst.free_func_inst = ecm_free_inst;
 880        opts->net = gether_setup_default();
 881        if (IS_ERR(opts->net)) {
 882                struct net_device *net = opts->net;
 883                kfree(opts);
 884                return ERR_CAST(net);
 885        }
 886
 887        config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
 888
 889        return &opts->func_inst;
 890}
 891
 892static void ecm_free(struct usb_function *f)
 893{
 894        struct f_ecm *ecm;
 895        struct f_ecm_opts *opts;
 896
 897        ecm = func_to_ecm(f);
 898        opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 899        kfree(ecm);
 900        mutex_lock(&opts->lock);
 901        opts->refcnt--;
 902        mutex_unlock(&opts->lock);
 903}
 904
 905static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 906{
 907        struct f_ecm            *ecm = func_to_ecm(f);
 908
 909        DBG(c->cdev, "ecm unbind\n");
 910
 911        usb_free_all_descriptors(f);
 912
 913        if (atomic_read(&ecm->notify_count)) {
 914                usb_ep_dequeue(ecm->notify, ecm->notify_req);
 915                atomic_set(&ecm->notify_count, 0);
 916        }
 917
 918        kfree(ecm->notify_req->buf);
 919        usb_ep_free_request(ecm->notify, ecm->notify_req);
 920}
 921
 922static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
 923{
 924        struct f_ecm    *ecm;
 925        struct f_ecm_opts *opts;
 926        int status;
 927
 928        /* allocate and initialize one new instance */
 929        ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
 930        if (!ecm)
 931                return ERR_PTR(-ENOMEM);
 932
 933        opts = container_of(fi, struct f_ecm_opts, func_inst);
 934        mutex_lock(&opts->lock);
 935        opts->refcnt++;
 936
 937        /* export host's Ethernet address in CDC format */
 938        status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
 939                                          sizeof(ecm->ethaddr));
 940        if (status < 12) {
 941                kfree(ecm);
 942                mutex_unlock(&opts->lock);
 943                return ERR_PTR(-EINVAL);
 944        }
 945
 946        ecm->port.ioport = netdev_priv(opts->net);
 947        mutex_unlock(&opts->lock);
 948        ecm->port.cdc_filter = DEFAULT_FILTER;
 949
 950        ecm->port.func.name = "cdc_ethernet";
 951        /* descriptors are per-instance copies */
 952        ecm->port.func.bind = ecm_bind;
 953        ecm->port.func.unbind = ecm_unbind;
 954        ecm->port.func.set_alt = ecm_set_alt;
 955        ecm->port.func.get_alt = ecm_get_alt;
 956        ecm->port.func.setup = ecm_setup;
 957        ecm->port.func.disable = ecm_disable;
 958        ecm->port.func.free_func = ecm_free;
 959
 960        return &ecm->port.func;
 961}
 962
 963DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
 964MODULE_LICENSE("GPL");
 965MODULE_AUTHOR("David Brownell");
 966