drivers/usb/gadget/f_ecm.c

   1 /*
   2  * f_ecm.c -- USB CDC Ethernet (ECM) link function driver
   3  *
   4  * Copyright (C) 2003-2005,2008 David Brownell
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 /* #define VERBOSE_DEBUG */
  14
  15 #include <linux/slab.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/device.h>
  19 #include <linux/etherdevice.h>
  20
  21 #include "u_ether.h"
  22 #include "u_ecm.h"
  23
  24
  25 /*
  26  * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  27  * Ethernet link.  The data transfer model is simple (packets sent and
  28  * received over bulk endpoints using normal short packet termination),
  29  * and the control model exposes various data and optional notifications.
  30  *
  31  * ECM is well standardized and (except for Microsoft) supported by most
  32  * operating systems with USB host support.  It's the preferred interop
  33  * solution for Ethernet over USB, at least for firmware based solutions.
  34  * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  35  * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  36  *
  37  * Note that ECM requires the use of "alternate settings" for its data
  38  * interface.  This means that the set_alt() method has real work to do,
  39  * and also means that a get_alt() method is required.
  40  */
  41
  42
  43 enum ecm_notify_state {
  44         ECM_NOTIFY_NONE,                /* don't notify */
  45         ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  46         ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  47 };
  48
  49 struct f_ecm {
  50         struct gether                   port;
  51         u8                              ctrl_id, data_id;
  52
  53         char                            ethaddr[14];
  54
  55         struct usb_ep                   *notify;
  56         struct usb_request              *notify_req;
  57         u8                              notify_state;
  58         bool                            is_open;
  59
  60         /* FIXME is_open needs some irq-ish locking
  61          * ... possibly the same as port.ioport
  62          */
  63 };
  64
  65 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  66 {
  67         return container_of(f, struct f_ecm, port.func);
  68 }
  69
  70 /* peak (theoretical) bulk transfer rate in bits-per-second */
  71 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  72 {
  73         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  74                 return 13 * 1024 * 8 * 1000 * 8;
  75         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  76                 return 13 * 512 * 8 * 1000 * 8;
  77         else
  78                 return 19 * 64 * 1 * 1000 * 8;
  79 }
  80
  81 /*-------------------------------------------------------------------------*/
  82
  83 /*
  84  * Include the status endpoint if we can, even though it's optional.
  85  *
  86  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
  87  * packet, to simplify cancellation; and a big transfer interval, to
  88  * waste less bandwidth.
  89  *
  90  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
  91  * if they ignore the connect/disconnect notifications that real aether
  92  * can provide.  More advanced cdc configurations might want to support
  93  * encapsulated commands (vendor-specific, using control-OUT).
  94  */
  95
  96 #define ECM_STATUS_INTERVAL_MS          32
  97 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
  98
  99
 100 /* interface descriptor: */
 101
 102 static struct usb_interface_assoc_descriptor
 103 ecm_iad_descriptor = {
 104         .bLength =              sizeof ecm_iad_descriptor,
 105         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 106
 107         /* .bFirstInterface =   DYNAMIC, */
 108         .bInterfaceCount =      2,      /* control + data */
 109         .bFunctionClass =       USB_CLASS_COMM,
 110         .bFunctionSubClass =    USB_CDC_SUBCLASS_ETHERNET,
 111         .bFunctionProtocol =    USB_CDC_PROTO_NONE,
 112         /* .iFunction =         DYNAMIC */
 113 };
 114
 115
 116 static struct usb_interface_descriptor ecm_control_intf = {
 117         .bLength =              sizeof ecm_control_intf,
 118         .bDescriptorType =      USB_DT_INTERFACE,
 119
 120         /* .bInterfaceNumber = DYNAMIC */
 121         /* status endpoint is optional; this could be patched later */
 122         .bNumEndpoints =        1,
 123         .bInterfaceClass =      USB_CLASS_COMM,
 124         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 125         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 126         /* .iInterface = DYNAMIC */
 127 };
 128
 129 static struct usb_cdc_header_desc ecm_header_desc = {
 130         .bLength =              sizeof ecm_header_desc,
 131         .bDescriptorType =      USB_DT_CS_INTERFACE,
 132         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 133
 134         .bcdCDC =               cpu_to_le16(0x0110),
 135 };
 136
 137 static struct usb_cdc_union_desc ecm_union_desc = {
 138         .bLength =              sizeof(ecm_union_desc),
 139         .bDescriptorType =      USB_DT_CS_INTERFACE,
 140         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 141         /* .bMasterInterface0 = DYNAMIC */
 142         /* .bSlaveInterface0 =  DYNAMIC */
 143 };
 144
 145 static struct usb_cdc_ether_desc ecm_desc = {
 146         .bLength =              sizeof ecm_desc,
 147         .bDescriptorType =      USB_DT_CS_INTERFACE,
 148         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 149
 150         /* this descriptor actually adds value, surprise! */
 151         /* .iMACAddress = DYNAMIC */
 152         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 153         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 154         .wNumberMCFilters =     cpu_to_le16(0),
 155         .bNumberPowerFilters =  0,
 156 };
 157
 158 /* the default data interface has no endpoints ... */
 159
 160 static struct usb_interface_descriptor ecm_data_nop_intf = {
 161         .bLength =              sizeof ecm_data_nop_intf,
 162         .bDescriptorType =      USB_DT_INTERFACE,
 163
 164         .bInterfaceNumber =     1,
 165         .bAlternateSetting =    0,
 166         .bNumEndpoints =        0,
 167         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 168         .bInterfaceSubClass =   0,
 169         .bInterfaceProtocol =   0,
 170         /* .iInterface = DYNAMIC */
 171 };
 172
 173 /* ... but the "real" data interface has two bulk endpoints */
 174
 175 static struct usb_interface_descriptor ecm_data_intf = {
 176         .bLength =              sizeof ecm_data_intf,
 177         .bDescriptorType =      USB_DT_INTERFACE,
 178
 179         .bInterfaceNumber =     1,
 180         .bAlternateSetting =    1,
 181         .bNumEndpoints =        2,
 182         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 183         .bInterfaceSubClass =   0,
 184         .bInterfaceProtocol =   0,
 185         /* .iInterface = DYNAMIC */
 186 };
 187
 188 /* full speed support: */
 189
 190 static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 191         .bLength =              USB_DT_ENDPOINT_SIZE,
 192         .bDescriptorType =      USB_DT_ENDPOINT,
 193
 194         .bEndpointAddress =     USB_DIR_IN,
 195         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 196         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 197         .bInterval =            ECM_STATUS_INTERVAL_MS,
 198 };
 199
 200 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 201         .bLength =              USB_DT_ENDPOINT_SIZE,
 202         .bDescriptorType =      USB_DT_ENDPOINT,
 203
 204         .bEndpointAddress =     USB_DIR_IN,
 205         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 206 };
 207
 208 static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 209         .bLength =              USB_DT_ENDPOINT_SIZE,
 210         .bDescriptorType =      USB_DT_ENDPOINT,
 211
 212         .bEndpointAddress =     USB_DIR_OUT,
 213         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 214 };
 215
 216 static struct usb_descriptor_header *ecm_fs_function[] = {
 217         /* CDC ECM control descriptors */
 218         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 219         (struct usb_descriptor_header *) &ecm_control_intf,
 220         (struct usb_descriptor_header *) &ecm_header_desc,
 221         (struct usb_descriptor_header *) &ecm_union_desc,
 222         (struct usb_descriptor_header *) &ecm_desc,
 223
 224         /* NOTE: status endpoint might need to be removed */
 225         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 226
 227         /* data interface, altsettings 0 and 1 */
 228         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 229         (struct usb_descriptor_header *) &ecm_data_intf,
 230         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 231         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 232         NULL,
 233 };
 234
 235 /* high speed support: */
 236
 237 static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 238         .bLength =              USB_DT_ENDPOINT_SIZE,
 239         .bDescriptorType =      USB_DT_ENDPOINT,
 240
 241         .bEndpointAddress =     USB_DIR_IN,
 242         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 243         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 244         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 245 };
 246
 247 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 248         .bLength =              USB_DT_ENDPOINT_SIZE,
 249         .bDescriptorType =      USB_DT_ENDPOINT,
 250
 251         .bEndpointAddress =     USB_DIR_IN,
 252         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 253         .wMaxPacketSize =       cpu_to_le16(512),
 254 };
 255
 256 static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 257         .bLength =              USB_DT_ENDPOINT_SIZE,
 258         .bDescriptorType =      USB_DT_ENDPOINT,
 259
 260         .bEndpointAddress =     USB_DIR_OUT,
 261         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 262         .wMaxPacketSize =       cpu_to_le16(512),
 263 };
 264
 265 static struct usb_descriptor_header *ecm_hs_function[] = {
 266         /* CDC ECM control descriptors */
 267         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 268         (struct usb_descriptor_header *) &ecm_control_intf,
 269         (struct usb_descriptor_header *) &ecm_header_desc,
 270         (struct usb_descriptor_header *) &ecm_union_desc,
 271         (struct usb_descriptor_header *) &ecm_desc,
 272
 273         /* NOTE: status endpoint might need to be removed */
 274         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 275
 276         /* data interface, altsettings 0 and 1 */
 277         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 278         (struct usb_descriptor_header *) &ecm_data_intf,
 279         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 280         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 281         NULL,
 282 };
 283
 284 /* super speed support: */
 285
 286 static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 287         .bLength =              USB_DT_ENDPOINT_SIZE,
 288         .bDescriptorType =      USB_DT_ENDPOINT,
 289
 290         .bEndpointAddress =     USB_DIR_IN,
 291         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 292         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 293         .bInterval =            USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 294 };
 295
 296 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 297         .bLength =              sizeof ss_ecm_intr_comp_desc,
 298         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 299
 300         /* the following 3 values can be tweaked if necessary */
 301         /* .bMaxBurst =         0, */
 302         /* .bmAttributes =      0, */
 303         .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 304 };
 305
 306 static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 307         .bLength =              USB_DT_ENDPOINT_SIZE,
 308         .bDescriptorType =      USB_DT_ENDPOINT,
 309
 310         .bEndpointAddress =     USB_DIR_IN,
 311         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 312         .wMaxPacketSize =       cpu_to_le16(1024),
 313 };
 314
 315 static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 316         .bLength =              USB_DT_ENDPOINT_SIZE,
 317         .bDescriptorType =      USB_DT_ENDPOINT,
 318
 319         .bEndpointAddress =     USB_DIR_OUT,
 320         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 321         .wMaxPacketSize =       cpu_to_le16(1024),
 322 };
 323
 324 static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 325         .bLength =              sizeof ss_ecm_bulk_comp_desc,
 326         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 327
 328         /* the following 2 values can be tweaked if necessary */
 329         /* .bMaxBurst =         0, */
 330         /* .bmAttributes =      0, */
 331 };
 332
 333 static struct usb_descriptor_header *ecm_ss_function[] = {
 334         /* CDC ECM control descriptors */
 335         (struct usb_descriptor_header *) &ecm_iad_descriptor,
 336         (struct usb_descriptor_header *) &ecm_control_intf,
 337         (struct usb_descriptor_header *) &ecm_header_desc,
 338         (struct usb_descriptor_header *) &ecm_union_desc,
 339         (struct usb_descriptor_header *) &ecm_desc,
 340
 341         /* NOTE: status endpoint might need to be removed */
 342         (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 343         (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 344
 345         /* data interface, altsettings 0 and 1 */
 346         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 347         (struct usb_descriptor_header *) &ecm_data_intf,
 348         (struct usb_descriptor_header *) &ss_ecm_in_desc,
 349         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 350         (struct usb_descriptor_header *) &ss_ecm_out_desc,
 351         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 352         NULL,
 353 };
 354
 355 /* string descriptors: */
 356
 357 static struct usb_string ecm_string_defs[] = {
 358         [0].s = "CDC Ethernet Control Model (ECM)",
 359         [1].s = "",
 360         [2].s = "CDC Ethernet Data",
 361         [3].s = "CDC ECM",
 362         {  } /* end of list */
 363 };
 364
 365 static struct usb_gadget_strings ecm_string_table = {
 366         .language =             0x0409, /* en-us */
 367         .strings =              ecm_string_defs,
 368 };
 369
 370 static struct usb_gadget_strings *ecm_strings[] = {
 371         &ecm_string_table,
 372         NULL,
 373 };
 374
 375 /*-------------------------------------------------------------------------*/
 376
 377 static void ecm_do_notify(struct f_ecm *ecm)
 378 {
 379         struct usb_request              *req = ecm->notify_req;
 380         struct usb_cdc_notification     *event;
 381         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 382         __le32                          *data;
 383         int                             status;
 384
 385         /* notification already in flight? */
 386         if (!req)
 387                 return;
 388
 389         event = req->buf;
 390         switch (ecm->notify_state) {
 391         case ECM_NOTIFY_NONE:
 392                 return;
 393
 394         case ECM_NOTIFY_CONNECT:
 395                 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 396                 if (ecm->is_open)
 397                         event->wValue = cpu_to_le16(1);
 398                 else
 399                         event->wValue = cpu_to_le16(0);
 400                 event->wLength = 0;
 401                 req->length = sizeof *event;
 402
 403                 DBG(cdev, "notify connect %s\n",
 404                                 ecm->is_open ? "true" : "false");
 405                 ecm->notify_state = ECM_NOTIFY_SPEED;
 406                 break;
 407
 408         case ECM_NOTIFY_SPEED:
 409                 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 410                 event->wValue = cpu_to_le16(0);
 411                 event->wLength = cpu_to_le16(8);
 412                 req->length = ECM_STATUS_BYTECOUNT;
 413
 414                 /* SPEED_CHANGE data is up/down speeds in bits/sec */
 415                 data = req->buf + sizeof *event;
 416                 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 417                 data[1] = data[0];
 418
 419                 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 420                 ecm->notify_state = ECM_NOTIFY_NONE;
 421                 break;
 422         }
 423         event->bmRequestType = 0xA1;
 424         event->wIndex = cpu_to_le16(ecm->ctrl_id);
 425
 426         ecm->notify_req = NULL;
 427         status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 428         if (status < 0) {
 429                 ecm->notify_req = req;
 430                 DBG(cdev, "notify --> %d\n", status);
 431         }
 432 }
 433
 434 static void ecm_notify(struct f_ecm *ecm)
 435 {
 436         /* NOTE on most versions of Linux, host side cdc-ethernet
 437          * won't listen for notifications until its netdevice opens.
 438          * The first notification then sits in the FIFO for a long
 439          * time, and the second one is queued.
 440          */
 441         ecm->notify_state = ECM_NOTIFY_CONNECT;
 442         ecm_do_notify(ecm);
 443 }
 444
 445 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 446 {
 447         struct f_ecm                    *ecm = req->context;
 448         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 449         struct usb_cdc_notification     *event = req->buf;
 450
 451         switch (req->status) {
 452         case 0:
 453                 /* no fault */
 454                 break;
 455         case -ECONNRESET:
 456         case -ESHUTDOWN:
 457                 ecm->notify_state = ECM_NOTIFY_NONE;
 458                 break;
 459         default:
 460                 DBG(cdev, "event %02x --> %d\n",
 461                         event->bNotificationType, req->status);
 462                 break;
 463         }
 464         ecm->notify_req = req;
 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                 if (ecm->notify->driver_data) {
 544                         VDBG(cdev, "reset ecm control %d\n", intf);
 545                         usb_ep_disable(ecm->notify);
 546                 }
 547                 if (!(ecm->notify->desc)) {
 548                         VDBG(cdev, "init ecm ctrl %d\n", intf);
 549                         if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 550                                 goto fail;
 551                 }
 552                 usb_ep_enable(ecm->notify);
 553                 ecm->notify->driver_data = ecm;
 554
 555         /* Data interface has two altsettings, 0 and 1 */
 556         } else if (intf == ecm->data_id) {
 557                 if (alt > 1)
 558                         goto fail;
 559
 560                 if (ecm->port.in_ep->driver_data) {
 561                         DBG(cdev, "reset ecm\n");
 562                         gether_disconnect(&ecm->port);
 563                 }
 564
 565                 if (!ecm->port.in_ep->desc ||
 566                     !ecm->port.out_ep->desc) {
 567                         DBG(cdev, "init ecm\n");
 568                         if (config_ep_by_speed(cdev->gadget, f,
 569                                                ecm->port.in_ep) ||
 570                             config_ep_by_speed(cdev->gadget, f,
 571                                                ecm->port.out_ep)) {
 572                                 ecm->port.in_ep->desc = NULL;
 573                                 ecm->port.out_ep->desc = NULL;
 574                                 goto fail;
 575                         }
 576                 }
 577
 578                 /* CDC Ethernet only sends data in non-default altsettings.
 579                  * Changing altsettings resets filters, statistics, etc.
 580                  */
 581                 if (alt == 1) {
 582                         struct net_device       *net;
 583
 584                         /* Enable zlps by default for ECM conformance;
 585                          * override for musb_hdrc (avoids txdma ovhead).
 586                          */
 587                         ecm->port.is_zlp_ok = !(gadget_is_musbhdrc(cdev->gadget)
 588                                 );
 589                         ecm->port.cdc_filter = DEFAULT_FILTER;
 590                         DBG(cdev, "activate ecm\n");
 591                         net = gether_connect(&ecm->port);
 592                         if (IS_ERR(net))
 593                                 return PTR_ERR(net);
 594                 }
 595
 596                 /* NOTE this can be a minor disagreement with the ECM spec,
 597                  * which says speed notifications will "always" follow
 598                  * connection notifications.  But we allow one connect to
 599                  * follow another (if the first is in flight), and instead
 600                  * just guarantee that a speed notification is always sent.
 601                  */
 602                 ecm_notify(ecm);
 603         } else
 604                 goto fail;
 605
 606         return 0;
 607 fail:
 608         return -EINVAL;
 609 }
 610
 611 /* Because the data interface supports multiple altsettings,
 612  * this ECM function *MUST* implement a get_alt() method.
 613  */
 614 static int ecm_get_alt(struct usb_function *f, unsigned intf)
 615 {
 616         struct f_ecm            *ecm = func_to_ecm(f);
 617
 618         if (intf == ecm->ctrl_id)
 619                 return 0;
 620         return ecm->port.in_ep->driver_data ? 1 : 0;
 621 }
 622
 623 static void ecm_disable(struct usb_function *f)
 624 {
 625         struct f_ecm            *ecm = func_to_ecm(f);
 626         struct usb_composite_dev *cdev = f->config->cdev;
 627
 628         DBG(cdev, "ecm deactivated\n");
 629
 630         if (ecm->port.in_ep->driver_data)
 631                 gether_disconnect(&ecm->port);
 632
 633         if (ecm->notify->driver_data) {
 634                 usb_ep_disable(ecm->notify);
 635                 ecm->notify->driver_data = NULL;
 636                 ecm->notify->desc = NULL;
 637         }
 638 }
 639
 640 /*-------------------------------------------------------------------------*/
 641
 642 /*
 643  * Callbacks let us notify the host about connect/disconnect when the
 644  * net device is opened or closed.
 645  *
 646  * For testing, note that link states on this side include both opened
 647  * and closed variants of:
 648  *
 649  *   - disconnected/unconfigured
 650  *   - configured but inactive (data alt 0)
 651  *   - configured and active (data alt 1)
 652  *
 653  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 654  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 655  * imply the host is actually polling the notification endpoint, and
 656  * likewise that "active" doesn't imply it's actually using the data
 657  * endpoints for traffic.
 658  */
 659
 660 static void ecm_open(struct gether *geth)
 661 {
 662         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 663
 664         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 665
 666         ecm->is_open = true;
 667         ecm_notify(ecm);
 668 }
 669
 670 static void ecm_close(struct gether *geth)
 671 {
 672         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 673
 674         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 675
 676         ecm->is_open = false;
 677         ecm_notify(ecm);
 678 }
 679
 680 /*-------------------------------------------------------------------------*/
 681
 682 /* ethernet function driver setup/binding */
 683
 684 static int
 685 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 686 {
 687         struct usb_composite_dev *cdev = c->cdev;
 688         struct f_ecm            *ecm = func_to_ecm(f);
 689         struct usb_string       *us;
 690         int                     status;
 691         struct usb_ep           *ep;
 692
 693 #ifndef USBF_ECM_INCLUDED
 694         struct f_ecm_opts       *ecm_opts;
 695
 696         if (!can_support_ecm(cdev->gadget))
 697                 return -EINVAL;
 698
 699         ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 700
 701         /*
 702          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 703          * configurations are bound in sequence with list_for_each_entry,
 704          * in each configuration its functions are bound in sequence
 705          * with list_for_each_entry, so we assume no race condition
 706          * with regard to ecm_opts->bound access
 707          */
 708         if (!ecm_opts->bound) {
 709                 gether_set_gadget(ecm_opts->net, cdev->gadget);
 710                 status = gether_register_netdev(ecm_opts->net);
 711                 if (status)
 712                         return status;
 713                 ecm_opts->bound = true;
 714         }
 715 #endif
 716         us = usb_gstrings_attach(cdev, ecm_strings,
 717                                  ARRAY_SIZE(ecm_string_defs));
 718         if (IS_ERR(us))
 719                 return PTR_ERR(us);
 720         ecm_control_intf.iInterface = us[0].id;
 721         ecm_data_intf.iInterface = us[2].id;
 722         ecm_desc.iMACAddress = us[1].id;
 723         ecm_iad_descriptor.iFunction = us[3].id;
 724
 725         /* allocate instance-specific interface IDs */
 726         status = usb_interface_id(c, f);
 727         if (status < 0)
 728                 goto fail;
 729         ecm->ctrl_id = status;
 730         ecm_iad_descriptor.bFirstInterface = status;
 731
 732         ecm_control_intf.bInterfaceNumber = status;
 733         ecm_union_desc.bMasterInterface0 = status;
 734
 735         status = usb_interface_id(c, f);
 736         if (status < 0)
 737                 goto fail;
 738         ecm->data_id = status;
 739
 740         ecm_data_nop_intf.bInterfaceNumber = status;
 741         ecm_data_intf.bInterfaceNumber = status;
 742         ecm_union_desc.bSlaveInterface0 = status;
 743
 744         status = -ENODEV;
 745
 746         /* allocate instance-specific endpoints */
 747         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 748         if (!ep)
 749                 goto fail;
 750         ecm->port.in_ep = ep;
 751         ep->driver_data = cdev; /* claim */
 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         ep->driver_data = cdev; /* claim */
 758
 759         /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 760          * don't treat it that way.  It's simpler, and some newer CDC
 761          * profiles (wireless handsets) no longer treat it as optional.
 762          */
 763         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 764         if (!ep)
 765                 goto fail;
 766         ecm->notify = ep;
 767         ep->driver_data = cdev; /* claim */
 768
 769         status = -ENOMEM;
 770
 771         /* allocate notification request and buffer */
 772         ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 773         if (!ecm->notify_req)
 774                 goto fail;
 775         ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 776         if (!ecm->notify_req->buf)
 777                 goto fail;
 778         ecm->notify_req->context = ecm;
 779         ecm->notify_req->complete = ecm_notify_complete;
 780
 781         /* support all relevant hardware speeds... we expect that when
 782          * hardware is dual speed, all bulk-capable endpoints work at
 783          * both speeds
 784          */
 785         hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 786         hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 787         hs_ecm_notify_desc.bEndpointAddress =
 788                 fs_ecm_notify_desc.bEndpointAddress;
 789
 790         ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
 791         ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
 792         ss_ecm_notify_desc.bEndpointAddress =
 793                 fs_ecm_notify_desc.bEndpointAddress;
 794
 795         status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
 796                         ecm_ss_function);
 797         if (status)
 798                 goto fail;
 799
 800         /* NOTE:  all that is done without knowing or caring about
 801          * the network link ... which is unavailable to this code
 802          * until we're activated via set_alt().
 803          */
 804
 805         ecm->port.open = ecm_open;
 806         ecm->port.close = ecm_close;
 807
 808         DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 809                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 810                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 811                         ecm->port.in_ep->name, ecm->port.out_ep->name,
 812                         ecm->notify->name);
 813         return 0;
 814
 815 fail:
 816         if (ecm->notify_req) {
 817                 kfree(ecm->notify_req->buf);
 818                 usb_ep_free_request(ecm->notify, ecm->notify_req);
 819         }
 820
 821         /* we might as well release our claims on endpoints */
 822         if (ecm->notify)
 823                 ecm->notify->driver_data = NULL;
 824         if (ecm->port.out_ep)
 825                 ecm->port.out_ep->driver_data = NULL;
 826         if (ecm->port.in_ep)
 827                 ecm->port.in_ep->driver_data = NULL;
 828
 829         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 830
 831         return status;
 832 }
 833
 834 #ifdef USBF_ECM_INCLUDED
 835
 836 static void
 837 ecm_old_unbind(struct usb_configuration *c, struct usb_function *f)
 838 {
 839         struct f_ecm            *ecm = func_to_ecm(f);
 840
 841         DBG(c->cdev, "ecm unbind\n");
 842
 843         usb_free_all_descriptors(f);
 844
 845         kfree(ecm->notify_req->buf);
 846         usb_ep_free_request(ecm->notify, ecm->notify_req);
 847         kfree(ecm);
 848 }
 849
 850 /**
 851  * ecm_bind_config - add CDC Ethernet network link to a configuration
 852  * @c: the configuration to support the network link
 853  * @ethaddr: a buffer in which the ethernet address of the host side
 854  *      side of the link was recorded
 855  * @dev: eth_dev structure
 856  * Context: single threaded during gadget setup
 857  *
 858  * Returns zero on success, else negative errno.
 859  *
 860  * Caller must have called @gether_setup().  Caller is also responsible
 861  * for calling @gether_cleanup() before module unload.
 862  */
 863 int
 864 ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
 865                 struct eth_dev *dev)
 866 {
 867         struct f_ecm    *ecm;
 868         int             status;
 869
 870         if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
 871                 return -EINVAL;
 872
 873         /* allocate and initialize one new instance */
 874         ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
 875         if (!ecm)
 876                 return -ENOMEM;
 877
 878         /* export host's Ethernet address in CDC format */
 879         snprintf(ecm->ethaddr, sizeof ecm->ethaddr, "%pm", ethaddr);
 880         ecm_string_defs[1].s = ecm->ethaddr;
 881
 882         ecm->port.ioport = dev;
 883         ecm->port.cdc_filter = DEFAULT_FILTER;
 884
 885         ecm->port.func.name = "cdc_ethernet";
 886         /* descriptors are per-instance copies */
 887         ecm->port.func.bind = ecm_bind;
 888         ecm->port.func.unbind = ecm_old_unbind;
 889         ecm->port.func.set_alt = ecm_set_alt;
 890         ecm->port.func.get_alt = ecm_get_alt;
 891         ecm->port.func.setup = ecm_setup;
 892         ecm->port.func.disable = ecm_disable;
 893
 894         status = usb_add_function(c, &ecm->port.func);
 895         if (status)
 896                 kfree(ecm);
 897         return status;
 898 }
 899
 900 #else
 901
 902 static void ecm_free_inst(struct usb_function_instance *f)
 903 {
 904         struct f_ecm_opts *opts;
 905
 906         opts = container_of(f, struct f_ecm_opts, func_inst);
 907         if (opts->bound)
 908                 gether_cleanup(netdev_priv(opts->net));
 909         else
 910                 free_netdev(opts->net);
 911         kfree(opts);
 912 }
 913
 914 static struct usb_function_instance *ecm_alloc_inst(void)
 915 {
 916         struct f_ecm_opts *opts;
 917
 918         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 919         if (!opts)
 920                 return ERR_PTR(-ENOMEM);
 921
 922         opts->func_inst.free_func_inst = ecm_free_inst;
 923         opts->net = gether_setup_default();
 924         if (IS_ERR(opts->net))
 925                 return ERR_PTR(PTR_ERR(opts->net));
 926
 927         return &opts->func_inst;
 928 }
 929
 930 static void ecm_free(struct usb_function *f)
 931 {
 932         struct f_ecm *ecm;
 933
 934         ecm = func_to_ecm(f);
 935         kfree(ecm);
 936 }
 937
 938 static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 939 {
 940         struct f_ecm            *ecm = func_to_ecm(f);
 941
 942         DBG(c->cdev, "ecm unbind\n");
 943
 944         usb_free_all_descriptors(f);
 945
 946         kfree(ecm->notify_req->buf);
 947         usb_ep_free_request(ecm->notify, ecm->notify_req);
 948 }
 949
 950 struct usb_function *ecm_alloc(struct usb_function_instance *fi)
 951 {
 952         struct f_ecm    *ecm;
 953         struct f_ecm_opts *opts;
 954         int status;
 955
 956         /* allocate and initialize one new instance */
 957         ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
 958         if (!ecm)
 959                 return ERR_PTR(-ENOMEM);
 960
 961         opts = container_of(fi, struct f_ecm_opts, func_inst);
 962
 963         /* export host's Ethernet address in CDC format */
 964         status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
 965                                           sizeof(ecm->ethaddr));
 966         if (status < 12) {
 967                 kfree(ecm);
 968                 return ERR_PTR(-EINVAL);
 969         }
 970         ecm_string_defs[1].s = ecm->ethaddr;
 971
 972         ecm->port.ioport = netdev_priv(opts->net);
 973         ecm->port.cdc_filter = DEFAULT_FILTER;
 974
 975         ecm->port.func.name = "cdc_ethernet";
 976         /* descriptors are per-instance copies */
 977         ecm->port.func.bind = ecm_bind;
 978         ecm->port.func.unbind = ecm_unbind;
 979         ecm->port.func.set_alt = ecm_set_alt;
 980         ecm->port.func.get_alt = ecm_get_alt;
 981         ecm->port.func.setup = ecm_setup;
 982         ecm->port.func.disable = ecm_disable;
 983         ecm->port.func.free_func = ecm_free;
 984
 985         return &ecm->port.func;
 986 }
 987
 988 DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
 989 MODULE_LICENSE("GPL");
 990 MODULE_AUTHOR("David Brownell");
 991
 992 #endif