drivers/usb/gadget/function/f_ecm.c

   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
  40 enum 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
  46 struct 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
  63 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  64 {
  65         return container_of(f, struct f_ecm, port.func);
  66 }
  67
  68 /* peak (theoretical) bulk transfer rate in bits-per-second */
  69 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  70 {
  71         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  72                 return 13 * 1024 * 8 * 1000 * 8;
  73         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  74                 return 13 * 512 * 8 * 1000 * 8;
  75         else
  76                 return 19 * 64 * 1 * 1000 * 8;
  77 }
  78
  79 /*-------------------------------------------------------------------------*/
  80
  81 /*
  82  * Include the status endpoint if we can, even though it's optional.
  83  *
  84  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
  85  * packet, to simplify cancellation; and a big transfer interval, to
  86  * waste less bandwidth.
  87  *
  88  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
  89  * if they ignore the connect/disconnect notifications that real aether
  90  * can provide.  More advanced cdc configurations might want to support
  91  * encapsulated commands (vendor-specific, using control-OUT).
  92  */
  93
  94 #define ECM_STATUS_INTERVAL_MS          32
  95 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  96
  97
  98 /* interface descriptor: */
  99
 100 static struct usb_interface_assoc_descriptor
 101 ecm_iad_descriptor = {
 102         .bLength =              sizeof ecm_iad_descriptor,
 103         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 104
 105         /* .bFirstInterface =   DYNAMIC, */
 106         .bInterfaceCount =      2,      /* control + data */
 107         .bFunctionClass =       USB_CLASS_COMM,
 108         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 109         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 110         /* .iFunction =         DYNAMIC */
 111 };
 112
 113
 114 static struct usb_interface_descriptor ecm_control_intf = {
 115         .bLength =              sizeof ecm_control_intf,
 116         .bDescriptorType =      USB_DT_INTERFACE,
 117
 118         /* .bInterfaceNumber = DYNAMIC */
 119         /* status endpoint is optional; this could be patched later */
 120         .bNumEndpoints =        1,
 121         .bInterfaceClass =      USB_CLASS_COMM,
 122         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 123         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 124         /* .iInterface = DYNAMIC */
 125 };
 126
 127 static struct usb_cdc_header_desc ecm_header_desc = {
 128         .bLength =              sizeof ecm_header_desc,
 129         .bDescriptorType =      USB_DT_CS_INTERFACE,
 130         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 131
 132         .bcdCDC =               cpu_to_le16(0x0110),
 133 };
 134
 135 static struct usb_cdc_union_desc ecm_union_desc = {
 136         .bLength =              sizeof(ecm_union_desc),
 137         .bDescriptorType =      USB_DT_CS_INTERFACE,
 138         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 139         /* .bMasterInterface0 = DYNAMIC */
 140         /* .bSlaveInterface0 =  DYNAMIC */
 141 };
 142
 143 static struct usb_cdc_ether_desc ecm_desc = {
 144         .bLength =              sizeof ecm_desc,
 145         .bDescriptorType =      USB_DT_CS_INTERFACE,
 146         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 147
 148         /* this descriptor actually adds value, surprise! */
 149         /* .iMACAddress = DYNAMIC */
 150         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 151         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 152         .wNumberMCFilters =     cpu_to_le16(0),
 153         .bNumberPowerFilters =  0,
 154 };
 155
 156 /* the default data interface has no endpoints ... */
 157
 158 static struct usb_interface_descriptor ecm_data_nop_intf = {
 159         .bLength =              sizeof ecm_data_nop_intf,
 160         .bDescriptorType =      USB_DT_INTERFACE,
 161
 162         .bInterfaceNumber =     1,
 163         .bAlternateSetting =    0,
 164         .bNumEndpoints =        0,
 165         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 166         .bInterfaceSubClass =   0,
 167         .bInterfaceProtocol =   0,
 168         /* .iInterface = DYNAMIC */
 169 };
 170
 171 /* ... but the "real" data interface has two bulk endpoints */
 172
 173 static struct usb_interface_descriptor ecm_data_intf = {
 174         .bLength =              sizeof ecm_data_intf,
 175         .bDescriptorType =      USB_DT_INTERFACE,
 176
 177         .bInterfaceNumber =     1,
 178         .bAlternateSetting =    1,
 179         .bNumEndpoints =        2,
 180         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 181         .bInterfaceSubClass =   0,
 182         .bInterfaceProtocol =   0,
 183         /* .iInterface = DYNAMIC */
 184 };
 185
 186 /* full speed support: */
 187
 188 static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 189         .bLength =              USB_DT_ENDPOINT_SIZE,
 190         .bDescriptorType =      USB_DT_ENDPOINT,
 191
 192         .bEndpointAddress =     USB_DIR_IN,
 193         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 194         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 195         .bInterval =            ECM_STATUS_INTERVAL_MS,
 196 };
 197
 198 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 199         .bLength =              USB_DT_ENDPOINT_SIZE,
 200         .bDescriptorType =      USB_DT_ENDPOINT,
 201
 202         .bEndpointAddress =     USB_DIR_IN,
 203         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 204 };
 205
 206 static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 207         .bLength =              USB_DT_ENDPOINT_SIZE,
 208         .bDescriptorType =      USB_DT_ENDPOINT,
 209
 210         .bEndpointAddress =     USB_DIR_OUT,
 211         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 212 };
 213
 214 static struct usb_descriptor_header *ecm_fs_function[] = {
 215         /* CDC ECM control descriptors */
 216         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 217         (struct usb_descriptor_header *) &ecm_control_intf,
 218         (struct usb_descriptor_header *) &ecm_header_desc,
 219         (struct usb_descriptor_header *) &ecm_union_desc,
 220         (struct usb_descriptor_header *) &ecm_desc,
 221
 222         /* NOTE: status endpoint might need to be removed */
 223         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 224
 225         /* data interface, altsettings 0 and 1 */
 226         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 227         (struct usb_descriptor_header *) &ecm_data_intf,
 228         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 229         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 230         NULL,
 231 };
 232
 233 /* high speed support: */
 234
 235 static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 236         .bLength =              USB_DT_ENDPOINT_SIZE,
 237         .bDescriptorType =      USB_DT_ENDPOINT,
 238
 239         .bEndpointAddress =     USB_DIR_IN,
 240         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 241         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 242         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 243 };
 244
 245 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 246         .bLength =              USB_DT_ENDPOINT_SIZE,
 247         .bDescriptorType =      USB_DT_ENDPOINT,
 248
 249         .bEndpointAddress =     USB_DIR_IN,
 250         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 251         .wMaxPacketSize =       cpu_to_le16(512),
 252 };
 253
 254 static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 255         .bLength =              USB_DT_ENDPOINT_SIZE,
 256         .bDescriptorType =      USB_DT_ENDPOINT,
 257
 258         .bEndpointAddress =     USB_DIR_OUT,
 259         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 260         .wMaxPacketSize =       cpu_to_le16(512),
 261 };
 262
 263 static struct usb_descriptor_header *ecm_hs_function[] = {
 264         /* CDC ECM control descriptors */
 265         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 266         (struct usb_descriptor_header *) &ecm_control_intf,
 267         (struct usb_descriptor_header *) &ecm_header_desc,
 268         (struct usb_descriptor_header *) &ecm_union_desc,
 269         (struct usb_descriptor_header *) &ecm_desc,
 270
 271         /* NOTE: status endpoint might need to be removed */
 272         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 273
 274         /* data interface, altsettings 0 and 1 */
 275         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 276         (struct usb_descriptor_header *) &ecm_data_intf,
 277         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 278         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 279         NULL,
 280 };
 281
 282 /* super speed support: */
 283
 284 static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 285         .bLength =              USB_DT_ENDPOINT_SIZE,
 286         .bDescriptorType =      USB_DT_ENDPOINT,
 287
 288         .bEndpointAddress =     USB_DIR_IN,
 289         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 290         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 291         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 292 };
 293
 294 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 295         .bLength =              sizeof ss_ecm_intr_comp_desc,
 296         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 297
 298         /* the following 3 values can be tweaked if necessary */
 299         /* .bMaxBurst =         0, */
 300         /* .bmAttributes =      0, */
 301         .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 302 };
 303
 304 static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 305         .bLength =              USB_DT_ENDPOINT_SIZE,
 306         .bDescriptorType =      USB_DT_ENDPOINT,
 307
 308         .bEndpointAddress =     USB_DIR_IN,
 309         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 310         .wMaxPacketSize =       cpu_to_le16(1024),
 311 };
 312
 313 static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 314         .bLength =              USB_DT_ENDPOINT_SIZE,
 315         .bDescriptorType =      USB_DT_ENDPOINT,
 316
 317         .bEndpointAddress =     USB_DIR_OUT,
 318         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 319         .wMaxPacketSize =       cpu_to_le16(1024),
 320 };
 321
 322 static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 323         .bLength =              sizeof ss_ecm_bulk_comp_desc,
 324         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 325
 326         /* the following 2 values can be tweaked if necessary */
 327         /* .bMaxBurst =         0, */
 328         /* .bmAttributes =      0, */
 329 };
 330
 331 static struct usb_descriptor_header *ecm_ss_function[] = {
 332         /* CDC ECM control descriptors */
 333         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 334         (struct usb_descriptor_header *) &ecm_control_intf,
 335         (struct usb_descriptor_header *) &ecm_header_desc,
 336         (struct usb_descriptor_header *) &ecm_union_desc,
 337         (struct usb_descriptor_header *) &ecm_desc,
 338
 339         /* NOTE: status endpoint might need to be removed */
 340         (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 341         (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 342
 343         /* data interface, altsettings 0 and 1 */
 344         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 345         (struct usb_descriptor_header *) &ecm_data_intf,
 346         (struct usb_descriptor_header *) &ss_ecm_in_desc,
 347         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 348         (struct usb_descriptor_header *) &ss_ecm_out_desc,
 349         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 350         NULL,
 351 };
 352
 353 /* string descriptors: */
 354
 355 static struct usb_string ecm_string_defs[] = {
 356         [0].s = "CDC Ethernet Control Model (ECM)",
 357         [1].s = "",
 358         [2].s = "CDC Ethernet Data",
 359         [3].s = "CDC ECM",
 360         {  } /* end of list */
 361 };
 362
 363 static struct usb_gadget_strings ecm_string_table = {
 364         .language =             0x0409, /* en-us */
 365         .strings =              ecm_string_defs,
 366 };
 367
 368 static struct usb_gadget_strings *ecm_strings[] = {
 369         &ecm_string_table,
 370         NULL,
 371 };
 372
 373 /*-------------------------------------------------------------------------*/
 374
 375 static void ecm_do_notify(struct f_ecm *ecm)
 376 {
 377         struct usb_request              *req = ecm->notify_req;
 378         struct usb_cdc_notification     *event;
 379         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 380         __le32                          *data;
 381         int                             status;
 382
 383         /* notification already in flight? */
 384         if (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
 432 static void ecm_notify(struct f_ecm *ecm)
 433 {
 434         /* NOTE on most versions of Linux, host side cdc-ethernet
 435          * won't listen for notifications until its netdevice opens.
 436          * The first notification then sits in the FIFO for a long
 437          * time, and the second one is queued.
 438          */
 439         ecm->notify_state = ECM_NOTIFY_CONNECT;
 440         ecm_do_notify(ecm);
 441 }
 442
 443 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 444 {
 445         struct f_ecm                    *ecm = req->context;
 446         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 447         struct usb_cdc_notification     *event = req->buf;
 448
 449         switch (req->status) {
 450         case 0:
 451                 /* no fault */
 452                 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
 468 static 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:
 508 invalid:
 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
 533 static 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;
 604 fail:
 605         return -EINVAL;
 606 }
 607
 608 /* Because the data interface supports multiple altsettings,
 609  * this ECM function *MUST* implement a get_alt() method.
 610  */
 611 static 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
 620 static 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
 658 static void ecm_open(struct gether *geth)
 659 {
 660         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 661
 662         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 663
 664         ecm->is_open = true;
 665         ecm_notify(ecm);
 666 }
 667
 668 static void ecm_close(struct gether *geth)
 669 {
 670         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 671
 672         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 673
 674         ecm->is_open = false;
 675         ecm_notify(ecm);
 676 }
 677
 678 /*-------------------------------------------------------------------------*/
 679
 680 /* ethernet function driver setup/binding */
 681
 682 static int
 683 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 684 {
 685         struct usb_composite_dev *cdev = c->cdev;
 686         struct f_ecm            *ecm = func_to_ecm(f);
 687         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, NULL);
 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
 813 fail:
 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
 824 static 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 */
 831 USB_ETHERNET_CONFIGFS_ITEM(ecm);
 832
 833 /* f_ecm_opts_dev_addr */
 834 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
 835
 836 /* f_ecm_opts_host_addr */
 837 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
 838
 839 /* f_ecm_opts_qmult */
 840 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
 841
 842 /* f_ecm_opts_ifname */
 843 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
 844
 845 static 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
 853 static 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
 859 static 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
 871 static 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
 892 static 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
 905 static 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
 922 static 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
 963 DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
 964 MODULE_LICENSE("GPL");
 965 MODULE_AUTHOR("David Brownell");