drivers/usb/gadget/function/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/module.h>
  18 #include <linux/device.h>
  19 #include <linux/etherdevice.h>
  20
  21 #include "u_ether.h"
  22 #include "u_ether_configfs.h"
  23 #include "u_ecm.h"
  24
  25
  26 /*
  27  * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  28  * Ethernet link.  The data transfer model is simple (packets sent and
  29  * received over bulk endpoints using normal short packet termination),
  30  * and the control model exposes various data and optional notifications.
  31  *
  32  * ECM is well standardized and (except for Microsoft) supported by most
  33  * operating systems with USB host support.  It's the preferred interop
  34  * solution for Ethernet over USB, at least for firmware based solutions.
  35  * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  36  * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  37  *
  38  * Note that ECM requires the use of "alternate settings" for its data
  39  * interface.  This means that the set_alt() method has real work to do,
  40  * and also means that a get_alt() method is required.
  41  */
  42
  43
  44 enum ecm_notify_state {
  45         ECM_NOTIFY_NONE,                /* don't notify */
  46         ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  47         ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  48 };
  49
  50 struct f_ecm {
  51         struct gether                   port;
  52         u8                              ctrl_id, data_id;
  53
  54         char                            ethaddr[14];
  55
  56         struct usb_ep                   *notify;
  57         struct usb_request              *notify_req;
  58         u8                              notify_state;
  59         bool                            is_open;
  60
  61         /* FIXME is_open needs some irq-ish locking
  62          * ... possibly the same as port.ioport
  63          */
  64 };
  65
  66 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  67 {
  68         return container_of(f, struct f_ecm, port.func);
  69 }
  70
  71 /* peak (theoretical) bulk transfer rate in bits-per-second */
  72 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  73 {
  74         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  75                 return 13 * 1024 * 8 * 1000 * 8;
  76         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  77                 return 13 * 512 * 8 * 1000 * 8;
  78         else
  79                 return 19 * 64 * 1 * 1000 * 8;
  80 }
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 /*
  85  * Include the status endpoint if we can, even though it's optional.
  86  *
  87  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
  88  * packet, to simplify cancellation; and a big transfer interval, to
  89  * waste less bandwidth.
  90  *
  91  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
  92  * if they ignore the connect/disconnect notifications that real aether
  93  * can provide.  More advanced cdc configurations might want to support
  94  * encapsulated commands (vendor-specific, using control-OUT).
  95  */
  96
  97 #define ECM_STATUS_INTERVAL_MS          32
  98 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  99
 100
 101 /* interface descriptor: */
 102
 103 static struct usb_interface_assoc_descriptor
 104 ecm_iad_descriptor = {
 105         .bLength =              sizeof ecm_iad_descriptor,
 106         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 107
 108         /* .bFirstInterface =   DYNAMIC, */
 109         .bInterfaceCount =      2,      /* control + data */
 110         .bFunctionClass =       USB_CLASS_COMM,
 111         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 112         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 113         /* .iFunction =         DYNAMIC */
 114 };
 115
 116
 117 static struct usb_interface_descriptor ecm_control_intf = {
 118         .bLength =              sizeof ecm_control_intf,
 119         .bDescriptorType =      USB_DT_INTERFACE,
 120
 121         /* .bInterfaceNumber = DYNAMIC */
 122         /* status endpoint is optional; this could be patched later */
 123         .bNumEndpoints =        1,
 124         .bInterfaceClass =      USB_CLASS_COMM,
 125         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 126         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 127         /* .iInterface = DYNAMIC */
 128 };
 129
 130 static struct usb_cdc_header_desc ecm_header_desc = {
 131         .bLength =              sizeof ecm_header_desc,
 132         .bDescriptorType =      USB_DT_CS_INTERFACE,
 133         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 134
 135         .bcdCDC =               cpu_to_le16(0x0110),
 136 };
 137
 138 static struct usb_cdc_union_desc ecm_union_desc = {
 139         .bLength =              sizeof(ecm_union_desc),
 140         .bDescriptorType =      USB_DT_CS_INTERFACE,
 141         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 142         /* .bMasterInterface0 = DYNAMIC */
 143         /* .bSlaveInterface0 =  DYNAMIC */
 144 };
 145
 146 static struct usb_cdc_ether_desc ecm_desc = {
 147         .bLength =              sizeof ecm_desc,
 148         .bDescriptorType =      USB_DT_CS_INTERFACE,
 149         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 150
 151         /* this descriptor actually adds value, surprise! */
 152         /* .iMACAddress = DYNAMIC */
 153         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 154         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 155         .wNumberMCFilters =     cpu_to_le16(0),
 156         .bNumberPowerFilters =  0,
 157 };
 158
 159 /* the default data interface has no endpoints ... */
 160
 161 static struct usb_interface_descriptor ecm_data_nop_intf = {
 162         .bLength =              sizeof ecm_data_nop_intf,
 163         .bDescriptorType =      USB_DT_INTERFACE,
 164
 165         .bInterfaceNumber =     1,
 166         .bAlternateSetting =    0,
 167         .bNumEndpoints =        0,
 168         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 169         .bInterfaceSubClass =   0,
 170         .bInterfaceProtocol =   0,
 171         /* .iInterface = DYNAMIC */
 172 };
 173
 174 /* ... but the "real" data interface has two bulk endpoints */
 175
 176 static struct usb_interface_descriptor ecm_data_intf = {
 177         .bLength =              sizeof ecm_data_intf,
 178         .bDescriptorType =      USB_DT_INTERFACE,
 179
 180         .bInterfaceNumber =     1,
 181         .bAlternateSetting =    1,
 182         .bNumEndpoints =        2,
 183         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 184         .bInterfaceSubClass =   0,
 185         .bInterfaceProtocol =   0,
 186         /* .iInterface = DYNAMIC */
 187 };
 188
 189 /* full speed support: */
 190
 191 static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 192         .bLength =              USB_DT_ENDPOINT_SIZE,
 193         .bDescriptorType =      USB_DT_ENDPOINT,
 194
 195         .bEndpointAddress =     USB_DIR_IN,
 196         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 197         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 198         .bInterval =            ECM_STATUS_INTERVAL_MS,
 199 };
 200
 201 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 202         .bLength =              USB_DT_ENDPOINT_SIZE,
 203         .bDescriptorType =      USB_DT_ENDPOINT,
 204
 205         .bEndpointAddress =     USB_DIR_IN,
 206         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 207 };
 208
 209 static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 210         .bLength =              USB_DT_ENDPOINT_SIZE,
 211         .bDescriptorType =      USB_DT_ENDPOINT,
 212
 213         .bEndpointAddress =     USB_DIR_OUT,
 214         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 215 };
 216
 217 static struct usb_descriptor_header *ecm_fs_function[] = {
 218         /* CDC ECM control descriptors */
 219         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 220         (struct usb_descriptor_header *) &ecm_control_intf,
 221         (struct usb_descriptor_header *) &ecm_header_desc,
 222         (struct usb_descriptor_header *) &ecm_union_desc,
 223         (struct usb_descriptor_header *) &ecm_desc,
 224
 225         /* NOTE: status endpoint might need to be removed */
 226         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 227
 228         /* data interface, altsettings 0 and 1 */
 229         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 230         (struct usb_descriptor_header *) &ecm_data_intf,
 231         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 232         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 233         NULL,
 234 };
 235
 236 /* high speed support: */
 237
 238 static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 239         .bLength =              USB_DT_ENDPOINT_SIZE,
 240         .bDescriptorType =      USB_DT_ENDPOINT,
 241
 242         .bEndpointAddress =     USB_DIR_IN,
 243         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 244         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 245         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 246 };
 247
 248 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 249         .bLength =              USB_DT_ENDPOINT_SIZE,
 250         .bDescriptorType =      USB_DT_ENDPOINT,
 251
 252         .bEndpointAddress =     USB_DIR_IN,
 253         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 254         .wMaxPacketSize =       cpu_to_le16(512),
 255 };
 256
 257 static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 258         .bLength =              USB_DT_ENDPOINT_SIZE,
 259         .bDescriptorType =      USB_DT_ENDPOINT,
 260
 261         .bEndpointAddress =     USB_DIR_OUT,
 262         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 263         .wMaxPacketSize =       cpu_to_le16(512),
 264 };
 265
 266 static struct usb_descriptor_header *ecm_hs_function[] = {
 267         /* CDC ECM control descriptors */
 268         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 269         (struct usb_descriptor_header *) &ecm_control_intf,
 270         (struct usb_descriptor_header *) &ecm_header_desc,
 271         (struct usb_descriptor_header *) &ecm_union_desc,
 272         (struct usb_descriptor_header *) &ecm_desc,
 273
 274         /* NOTE: status endpoint might need to be removed */
 275         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 276
 277         /* data interface, altsettings 0 and 1 */
 278         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 279         (struct usb_descriptor_header *) &ecm_data_intf,
 280         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 281         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 282         NULL,
 283 };
 284
 285 /* super speed support: */
 286
 287 static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 288         .bLength =              USB_DT_ENDPOINT_SIZE,
 289         .bDescriptorType =      USB_DT_ENDPOINT,
 290
 291         .bEndpointAddress =     USB_DIR_IN,
 292         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 293         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 294         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 295 };
 296
 297 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 298         .bLength =              sizeof ss_ecm_intr_comp_desc,
 299         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 300
 301         /* the following 3 values can be tweaked if necessary */
 302         /* .bMaxBurst =         0, */
 303         /* .bmAttributes =      0, */
 304         .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 305 };
 306
 307 static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 308         .bLength =              USB_DT_ENDPOINT_SIZE,
 309         .bDescriptorType =      USB_DT_ENDPOINT,
 310
 311         .bEndpointAddress =     USB_DIR_IN,
 312         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 313         .wMaxPacketSize =       cpu_to_le16(1024),
 314 };
 315
 316 static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 317         .bLength =              USB_DT_ENDPOINT_SIZE,
 318         .bDescriptorType =      USB_DT_ENDPOINT,
 319
 320         .bEndpointAddress =     USB_DIR_OUT,
 321         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 322         .wMaxPacketSize =       cpu_to_le16(1024),
 323 };
 324
 325 static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 326         .bLength =              sizeof ss_ecm_bulk_comp_desc,
 327         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 328
 329         /* the following 2 values can be tweaked if necessary */
 330         /* .bMaxBurst =         0, */
 331         /* .bmAttributes =      0, */
 332 };
 333
 334 static struct usb_descriptor_header *ecm_ss_function[] = {
 335         /* CDC ECM control descriptors */
 336         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 337         (struct usb_descriptor_header *) &ecm_control_intf,
 338         (struct usb_descriptor_header *) &ecm_header_desc,
 339         (struct usb_descriptor_header *) &ecm_union_desc,
 340         (struct usb_descriptor_header *) &ecm_desc,
 341
 342         /* NOTE: status endpoint might need to be removed */
 343         (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 344         (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 345
 346         /* data interface, altsettings 0 and 1 */
 347         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 348         (struct usb_descriptor_header *) &ecm_data_intf,
 349         (struct usb_descriptor_header *) &ss_ecm_in_desc,
 350         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 351         (struct usb_descriptor_header *) &ss_ecm_out_desc,
 352         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 353         NULL,
 354 };
 355
 356 /* string descriptors: */
 357
 358 static struct usb_string ecm_string_defs[] = {
 359         [0].s = "CDC Ethernet Control Model (ECM)",
 360         [1].s = "",
 361         [2].s = "CDC Ethernet Data",
 362         [3].s = "CDC ECM",
 363         {  } /* end of list */
 364 };
 365
 366 static struct usb_gadget_strings ecm_string_table = {
 367         .language =             0x0409, /* en-us */
 368         .strings =              ecm_string_defs,
 369 };
 370
 371 static struct usb_gadget_strings *ecm_strings[] = {
 372         &ecm_string_table,
 373         NULL,
 374 };
 375
 376 /*-------------------------------------------------------------------------*/
 377
 378 static void ecm_do_notify(struct f_ecm *ecm)
 379 {
 380         struct usb_request              *req = ecm->notify_req;
 381         struct usb_cdc_notification     *event;
 382         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 383         __le32                          *data;
 384         int                             status;
 385
 386         /* notification already in flight? */
 387         if (!req)
 388                 return;
 389
 390         event = req->buf;
 391         switch (ecm->notify_state) {
 392         case ECM_NOTIFY_NONE:
 393                 return;
 394
 395         case ECM_NOTIFY_CONNECT:
 396                 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 397                 if (ecm->is_open)
 398                         event->wValue = cpu_to_le16(1);
 399                 else
 400                         event->wValue = cpu_to_le16(0);
 401                 event->wLength = 0;
 402                 req->length = sizeof *event;
 403
 404                 DBG(cdev, "notify connect %s\n",
 405                                 ecm->is_open ? "true" : "false");
 406                 ecm->notify_state = ECM_NOTIFY_SPEED;
 407                 break;
 408
 409         case ECM_NOTIFY_SPEED:
 410                 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 411                 event->wValue = cpu_to_le16(0);
 412                 event->wLength = cpu_to_le16(8);
 413                 req->length = ECM_STATUS_BYTECOUNT;
 414
 415                 /* SPEED_CHANGE data is up/down speeds in bits/sec */
 416                 data = req->buf + sizeof *event;
 417                 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 418                 data[1] = data[0];
 419
 420                 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 421                 ecm->notify_state = ECM_NOTIFY_NONE;
 422                 break;
 423         }
 424         event->bmRequestType = 0xA1;
 425         event->wIndex = cpu_to_le16(ecm->ctrl_id);
 426
 427         ecm->notify_req = NULL;
 428         status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 429         if (status < 0) {
 430                 ecm->notify_req = req;
 431                 DBG(cdev, "notify --> %d\n", status);
 432         }
 433 }
 434
 435 static void ecm_notify(struct f_ecm *ecm)
 436 {
 437         /* NOTE on most versions of Linux, host side cdc-ethernet
 438          * won't listen for notifications until its netdevice opens.
 439          * The first notification then sits in the FIFO for a long
 440          * time, and the second one is queued.
 441          */
 442         ecm->notify_state = ECM_NOTIFY_CONNECT;
 443         ecm_do_notify(ecm);
 444 }
 445
 446 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 447 {
 448         struct f_ecm                    *ecm = req->context;
 449         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 450         struct usb_cdc_notification     *event = req->buf;
 451
 452         switch (req->status) {
 453         case 0:
 454                 /* no fault */
 455                 break;
 456         case -ECONNRESET:
 457         case -ESHUTDOWN:
 458                 ecm->notify_state = ECM_NOTIFY_NONE;
 459                 break;
 460         default:
 461                 DBG(cdev, "event %02x --> %d\n",
 462                         event->bNotificationType, req->status);
 463                 break;
 464         }
 465         ecm->notify_req = req;
 466         ecm_do_notify(ecm);
 467 }
 468
 469 static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 470 {
 471         struct f_ecm            *ecm = func_to_ecm(f);
 472         struct usb_composite_dev *cdev = f->config->cdev;
 473         struct usb_request      *req = cdev->req;
 474         int                     value = -EOPNOTSUPP;
 475         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 476         u16                     w_value = le16_to_cpu(ctrl->wValue);
 477         u16                     w_length = le16_to_cpu(ctrl->wLength);
 478
 479         /* composite driver infrastructure handles everything except
 480          * CDC class messages; interface activation uses set_alt().
 481          */
 482         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 483         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 484                         | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 485                 /* see 6.2.30: no data, wIndex = interface,
 486                  * wValue = packet filter bitmap
 487                  */
 488                 if (w_length != 0 || w_index != ecm->ctrl_id)
 489                         goto invalid;
 490                 DBG(cdev, "packet filter %02x\n", w_value);
 491                 /* REVISIT locking of cdc_filter.  This assumes the UDC
 492                  * driver won't have a concurrent packet TX irq running on
 493                  * another CPU; or that if it does, this write is atomic...
 494                  */
 495                 ecm->port.cdc_filter = w_value;
 496                 value = 0;
 497                 break;
 498
 499         /* and optionally:
 500          * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 501          * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 502          * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 503          * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 504          * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 505          * case USB_CDC_GET_ETHERNET_STATISTIC:
 506          */
 507
 508         default:
 509 invalid:
 510                 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 511                         ctrl->bRequestType, ctrl->bRequest,
 512                         w_value, w_index, w_length);
 513         }
 514
 515         /* respond with data transfer or status phase? */
 516         if (value >= 0) {
 517                 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 518                         ctrl->bRequestType, ctrl->bRequest,
 519                         w_value, w_index, w_length);
 520                 req->zero = 0;
 521                 req->length = value;
 522                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 523                 if (value < 0)
 524                         ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 525                                         ctrl->bRequestType, ctrl->bRequest,
 526                                         value);
 527         }
 528
 529         /* device either stalls (value < 0) or reports success */
 530         return value;
 531 }
 532
 533
 534 static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 535 {
 536         struct f_ecm            *ecm = func_to_ecm(f);
 537         struct usb_composite_dev *cdev = f->config->cdev;
 538
 539         /* Control interface has only altsetting 0 */
 540         if (intf == ecm->ctrl_id) {
 541                 if (alt != 0)
 542                         goto fail;
 543
 544                 VDBG(cdev, "reset ecm control %d\n", intf);
 545                 usb_ep_disable(ecm->notify);
 546                 if (!(ecm->notify->desc)) {
 547                         VDBG(cdev, "init ecm ctrl %d\n", intf);
 548                         if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 549                                 goto fail;
 550                 }
 551                 usb_ep_enable(ecm->notify);
 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->enabled) {
 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 =
 586                                 gadget_is_zlp_supported(cdev->gadget);
 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->enabled ? 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->enabled)
 629                 gether_disconnect(&ecm->port);
 630
 631         usb_ep_disable(ecm->notify);
 632         ecm->notify->desc = NULL;
 633 }
 634
 635 /*-------------------------------------------------------------------------*/
 636
 637 /*
 638  * Callbacks let us notify the host about connect/disconnect when the
 639  * net device is opened or closed.
 640  *
 641  * For testing, note that link states on this side include both opened
 642  * and closed variants of:
 643  *
 644  *   - disconnected/unconfigured
 645  *   - configured but inactive (data alt 0)
 646  *   - configured and active (data alt 1)
 647  *
 648  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 649  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 650  * imply the host is actually polling the notification endpoint, and
 651  * likewise that "active" doesn't imply it's actually using the data
 652  * endpoints for traffic.
 653  */
 654
 655 static void ecm_open(struct gether *geth)
 656 {
 657         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 658
 659         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 660
 661         ecm->is_open = true;
 662         ecm_notify(ecm);
 663 }
 664
 665 static void ecm_close(struct gether *geth)
 666 {
 667         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 668
 669         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 670
 671         ecm->is_open = false;
 672         ecm_notify(ecm);
 673 }
 674
 675 /*-------------------------------------------------------------------------*/
 676
 677 /* ethernet function driver setup/binding */
 678
 679 static int
 680 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 681 {
 682         struct usb_composite_dev *cdev = c->cdev;
 683         struct f_ecm            *ecm = func_to_ecm(f);
 684         struct usb_string       *us;
 685         int                     status;
 686         struct usb_ep           *ep;
 687
 688         struct f_ecm_opts       *ecm_opts;
 689
 690         if (!can_support_ecm(cdev->gadget))
 691                 return -EINVAL;
 692
 693         ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 694
 695         /*
 696          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 697          * configurations are bound in sequence with list_for_each_entry,
 698          * in each configuration its functions are bound in sequence
 699          * with list_for_each_entry, so we assume no race condition
 700          * with regard to ecm_opts->bound access
 701          */
 702         if (!ecm_opts->bound) {
 703                 mutex_lock(&ecm_opts->lock);
 704                 gether_set_gadget(ecm_opts->net, cdev->gadget);
 705                 status = gether_register_netdev(ecm_opts->net);
 706                 mutex_unlock(&ecm_opts->lock);
 707                 if (status)
 708                         return status;
 709                 ecm_opts->bound = true;
 710         }
 711
 712         us = usb_gstrings_attach(cdev, ecm_strings,
 713                                  ARRAY_SIZE(ecm_string_defs));
 714         if (IS_ERR(us))
 715                 return PTR_ERR(us);
 716         ecm_control_intf.iInterface = us[0].id;
 717         ecm_data_intf.iInterface = us[2].id;
 718         ecm_desc.iMACAddress = us[1].id;
 719         ecm_iad_descriptor.iFunction = us[3].id;
 720
 721         /* allocate instance-specific interface IDs */
 722         status = usb_interface_id(c, f);
 723         if (status < 0)
 724                 goto fail;
 725         ecm->ctrl_id = status;
 726         ecm_iad_descriptor.bFirstInterface = status;
 727
 728         ecm_control_intf.bInterfaceNumber = status;
 729         ecm_union_desc.bMasterInterface0 = status;
 730
 731         status = usb_interface_id(c, f);
 732         if (status < 0)
 733                 goto fail;
 734         ecm->data_id = status;
 735
 736         ecm_data_nop_intf.bInterfaceNumber = status;
 737         ecm_data_intf.bInterfaceNumber = status;
 738         ecm_union_desc.bSlaveInterface0 = status;
 739
 740         status = -ENODEV;
 741
 742         /* allocate instance-specific endpoints */
 743         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 744         if (!ep)
 745                 goto fail;
 746         ecm->port.in_ep = ep;
 747
 748         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 749         if (!ep)
 750                 goto fail;
 751         ecm->port.out_ep = ep;
 752
 753         /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 754          * don't treat it that way.  It's simpler, and some newer CDC
 755          * profiles (wireless handsets) no longer treat it as optional.
 756          */
 757         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 758         if (!ep)
 759                 goto fail;
 760         ecm->notify = ep;
 761
 762         status = -ENOMEM;
 763
 764         /* allocate notification request and buffer */
 765         ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 766         if (!ecm->notify_req)
 767                 goto fail;
 768         ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 769         if (!ecm->notify_req->buf)
 770                 goto fail;
 771         ecm->notify_req->context = ecm;
 772         ecm->notify_req->complete = ecm_notify_complete;
 773
 774         /* support all relevant hardware speeds... we expect that when
 775          * hardware is dual speed, all bulk-capable endpoints work at
 776          * both speeds
 777          */
 778         hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 779         hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 780         hs_ecm_notify_desc.bEndpointAddress =
 781                 fs_ecm_notify_desc.bEndpointAddress;
 782
 783         ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 784         ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 785         ss_ecm_notify_desc.bEndpointAddress =
 786                 fs_ecm_notify_desc.bEndpointAddress;
 787
 788         status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
 789                         ecm_ss_function);
 790         if (status)
 791                 goto fail;
 792
 793         /* NOTE:  all that is done without knowing or caring about
 794          * the network link ... which is unavailable to this code
 795          * until we're activated via set_alt().
 796          */
 797
 798         ecm->port.open = ecm_open;
 799         ecm->port.close = ecm_close;
 800
 801         DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 802                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 803                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 804                         ecm->port.in_ep->name, ecm->port.out_ep->name,
 805                         ecm->notify->name);
 806         return 0;
 807
 808 fail:
 809         if (ecm->notify_req) {
 810                 kfree(ecm->notify_req->buf);
 811                 usb_ep_free_request(ecm->notify, ecm->notify_req);
 812         }
 813
 814         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 815
 816         return status;
 817 }
 818
 819 static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
 820 {
 821         return container_of(to_config_group(item), struct f_ecm_opts,
 822                             func_inst.group);
 823 }
 824
 825 /* f_ecm_item_ops */
 826 USB_ETHERNET_CONFIGFS_ITEM(ecm);
 827
 828 /* f_ecm_opts_dev_addr */
 829 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
 830
 831 /* f_ecm_opts_host_addr */
 832 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
 833
 834 /* f_ecm_opts_qmult */
 835 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
 836
 837 /* f_ecm_opts_ifname */
 838 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
 839
 840 static struct configfs_attribute *ecm_attrs[] = {
 841         &ecm_opts_attr_dev_addr,
 842         &ecm_opts_attr_host_addr,
 843         &ecm_opts_attr_qmult,
 844         &ecm_opts_attr_ifname,
 845         NULL,
 846 };
 847
 848 static struct config_item_type ecm_func_type = {
 849         .ct_item_ops    = &ecm_item_ops,
 850         .ct_attrs       = ecm_attrs,
 851         .ct_owner       = THIS_MODULE,
 852 };
 853
 854 static void ecm_free_inst(struct usb_function_instance *f)
 855 {
 856         struct f_ecm_opts *opts;
 857
 858         opts = container_of(f, struct f_ecm_opts, func_inst);
 859         if (opts->bound)
 860                 gether_cleanup(netdev_priv(opts->net));
 861         else
 862                 free_netdev(opts->net);
 863         kfree(opts);
 864 }
 865
 866 static struct usb_function_instance *ecm_alloc_inst(void)
 867 {
 868         struct f_ecm_opts *opts;
 869
 870         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 871         if (!opts)
 872                 return ERR_PTR(-ENOMEM);
 873         mutex_init(&opts->lock);
 874         opts->func_inst.free_func_inst = ecm_free_inst;
 875         opts->net = gether_setup_default();
 876         if (IS_ERR(opts->net)) {
 877                 struct net_device *net = opts->net;
 878                 kfree(opts);
 879                 return ERR_CAST(net);
 880         }
 881
 882         config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
 883
 884         return &opts->func_inst;
 885 }
 886
 887 static void ecm_free(struct usb_function *f)
 888 {
 889         struct f_ecm *ecm;
 890         struct f_ecm_opts *opts;
 891
 892         ecm = func_to_ecm(f);
 893         opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 894         kfree(ecm);
 895         mutex_lock(&opts->lock);
 896         opts->refcnt--;
 897         mutex_unlock(&opts->lock);
 898 }
 899
 900 static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 901 {
 902         struct f_ecm            *ecm = func_to_ecm(f);
 903
 904         DBG(c->cdev, "ecm unbind\n");
 905
 906         usb_free_all_descriptors(f);
 907
 908         kfree(ecm->notify_req->buf);
 909         usb_ep_free_request(ecm->notify, ecm->notify_req);
 910 }
 911
 912 static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
 913 {
 914         struct f_ecm    *ecm;
 915         struct f_ecm_opts *opts;
 916         int status;
 917
 918         /* allocate and initialize one new instance */
 919         ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
 920         if (!ecm)
 921                 return ERR_PTR(-ENOMEM);
 922
 923         opts = container_of(fi, struct f_ecm_opts, func_inst);
 924         mutex_lock(&opts->lock);
 925         opts->refcnt++;
 926
 927         /* export host's Ethernet address in CDC format */
 928         status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
 929                                           sizeof(ecm->ethaddr));
 930         if (status < 12) {
 931                 kfree(ecm);
 932                 mutex_unlock(&opts->lock);
 933                 return ERR_PTR(-EINVAL);
 934         }
 935         ecm_string_defs[1].s = ecm->ethaddr;
 936
 937         ecm->port.ioport = netdev_priv(opts->net);
 938         mutex_unlock(&opts->lock);
 939         ecm->port.cdc_filter = DEFAULT_FILTER;
 940
 941         ecm->port.func.name = "cdc_ethernet";
 942         /* descriptors are per-instance copies */
 943         ecm->port.func.bind = ecm_bind;
 944         ecm->port.func.unbind = ecm_unbind;
 945         ecm->port.func.set_alt = ecm_set_alt;
 946         ecm->port.func.get_alt = ecm_get_alt;
 947         ecm->port.func.setup = ecm_setup;
 948         ecm->port.func.disable = ecm_disable;
 949         ecm->port.func.free_func = ecm_free;
 950
 951         return &ecm->port.func;
 952 }
 953
 954 DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
 955 MODULE_LICENSE("GPL");
 956 MODULE_AUTHOR("David Brownell");