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  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 /* #define VERBOSE_DEBUG */
  23
  24 #include <linux/slab.h>
  25 #include <linux/kernel.h>
  26 #include <linux/device.h>
  27 #include <linux/etherdevice.h>
  28
  29 #include "u_ether.h"
  30
  31
  32 /*
  33  * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
  34  * Ethernet link.  The data transfer model is simple (packets sent and
  35  * received over bulk endpoints using normal short packet termination),
  36  * and the control model exposes various data and optional notifications.
  37  *
  38  * ECM is well standardized and (except for Microsoft) supported by most
  39  * operating systems with USB host support.  It's the preferred interop
  40  * solution for Ethernet over USB, at least for firmware based solutions.
  41  * (Hardware solutions tend to be more minimalist.)  A newer and simpler
  42  * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
  43  *
  44  * Note that ECM requires the use of "alternate settings" for its data
  45  * interface.  This means that the set_alt() method has real work to do,
  46  * and also means that a get_alt() method is required.
  47  */
  48
  49
  50 enum ecm_notify_state {
  51         ECM_NOTIFY_NONE,                /* don't notify */
  52         ECM_NOTIFY_CONNECT,             /* issue CONNECT next */
  53         ECM_NOTIFY_SPEED,               /* issue SPEED_CHANGE next */
  54 };
  55
  56 struct f_ecm {
  57         struct gether                   port;
  58         u8                              ctrl_id, data_id;
  59
  60         char                            ethaddr[14];
  61
  62         struct usb_ep                   *notify;
  63         struct usb_request              *notify_req;
  64         u8                              notify_state;
  65         bool                            is_open;
  66
  67         /* FIXME is_open needs some irq-ish locking
  68          * ... possibly the same as port.ioport
  69          */
  70 };
  71
  72 static inline struct f_ecm *func_to_ecm(struct usb_function *f)
  73 {
  74         return container_of(f, struct f_ecm, port.func);
  75 }
  76
  77 /* peak (theoretical) bulk transfer rate in bits-per-second */
  78 static inline unsigned ecm_bitrate(struct usb_gadget *g)
  79 {
  80         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  81                 return 13 * 1024 * 8 * 1000 * 8;
  82         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  83                 return 13 * 512 * 8 * 1000 * 8;
  84         else
  85                 return 19 * 64 * 1 * 1000 * 8;
  86 }
  87
  88 /*-------------------------------------------------------------------------*/
  89
  90 /*
  91  * Include the status endpoint if we can, even though it's optional.
  92  *
  93  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
  94  * packet, to simplify cancellation; and a big transfer interval, to
  95  * waste less bandwidth.
  96  *
  97  * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
  98  * if they ignore the connect/disconnect notifications that real aether
  99  * can provide.  More advanced cdc configurations might want to support
 100  * encapsulated commands (vendor-specific, using control-OUT).
 101  */
 102
 103 #define LOG2_STATUS_INTERVAL_MSEC       5       /* 1 << 5 == 32 msec */
 104 #define ECM_STATUS_BYTECOUNT            16      /* 8 byte header + data */
 105
 106
 107 /* interface descriptor: */
 108
 109 static struct usb_interface_descriptor ecm_control_intf = {
 110         .bLength =              sizeof ecm_control_intf,
 111         .bDescriptorType =      USB_DT_INTERFACE,
 112
 113         /* .bInterfaceNumber = DYNAMIC */
 114         /* status endpoint is optional; this could be patched later */
 115         .bNumEndpoints =        1,
 116         .bInterfaceClass =      USB_CLASS_COMM,
 117         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ETHERNET,
 118         .bInterfaceProtocol =   USB_CDC_PROTO_NONE,
 119         /* .iInterface = DYNAMIC */
 120 };
 121
 122 static struct usb_cdc_header_desc ecm_header_desc = {
 123         .bLength =              sizeof ecm_header_desc,
 124         .bDescriptorType =      USB_DT_CS_INTERFACE,
 125         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 126
 127         .bcdCDC =               cpu_to_le16(0x0110),
 128 };
 129
 130 static struct usb_cdc_union_desc ecm_union_desc = {
 131         .bLength =              sizeof(ecm_union_desc),
 132         .bDescriptorType =      USB_DT_CS_INTERFACE,
 133         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 134         /* .bMasterInterface0 = DYNAMIC */
 135         /* .bSlaveInterface0 =  DYNAMIC */
 136 };
 137
 138 static struct usb_cdc_ether_desc ecm_desc = {
 139         .bLength =              sizeof ecm_desc,
 140         .bDescriptorType =      USB_DT_CS_INTERFACE,
 141         .bDescriptorSubType =   USB_CDC_ETHERNET_TYPE,
 142
 143         /* this descriptor actually adds value, surprise! */
 144         /* .iMACAddress = DYNAMIC */
 145         .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
 146         .wMaxSegmentSize =      cpu_to_le16(ETH_FRAME_LEN),
 147         .wNumberMCFilters =     cpu_to_le16(0),
 148         .bNumberPowerFilters =  0,
 149 };
 150
 151 /* the default data interface has no endpoints ... */
 152
 153 static struct usb_interface_descriptor ecm_data_nop_intf = {
 154         .bLength =              sizeof ecm_data_nop_intf,
 155         .bDescriptorType =      USB_DT_INTERFACE,
 156
 157         .bInterfaceNumber =     1,
 158         .bAlternateSetting =    0,
 159         .bNumEndpoints =        0,
 160         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 161         .bInterfaceSubClass =   0,
 162         .bInterfaceProtocol =   0,
 163         /* .iInterface = DYNAMIC */
 164 };
 165
 166 /* ... but the "real" data interface has two bulk endpoints */
 167
 168 static struct usb_interface_descriptor ecm_data_intf = {
 169         .bLength =              sizeof ecm_data_intf,
 170         .bDescriptorType =      USB_DT_INTERFACE,
 171
 172         .bInterfaceNumber =     1,
 173         .bAlternateSetting =    1,
 174         .bNumEndpoints =        2,
 175         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 176         .bInterfaceSubClass =   0,
 177         .bInterfaceProtocol =   0,
 178         /* .iInterface = DYNAMIC */
 179 };
 180
 181 /* full speed support: */
 182
 183 static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
 184         .bLength =              USB_DT_ENDPOINT_SIZE,
 185         .bDescriptorType =      USB_DT_ENDPOINT,
 186
 187         .bEndpointAddress =     USB_DIR_IN,
 188         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 189         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 190         .bInterval =            1 << LOG2_STATUS_INTERVAL_MSEC,
 191 };
 192
 193 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
 194         .bLength =              USB_DT_ENDPOINT_SIZE,
 195         .bDescriptorType =      USB_DT_ENDPOINT,
 196
 197         .bEndpointAddress =     USB_DIR_IN,
 198         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 199 };
 200
 201 static struct usb_endpoint_descriptor fs_ecm_out_desc = {
 202         .bLength =              USB_DT_ENDPOINT_SIZE,
 203         .bDescriptorType =      USB_DT_ENDPOINT,
 204
 205         .bEndpointAddress =     USB_DIR_OUT,
 206         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 207 };
 208
 209 static struct usb_descriptor_header *ecm_fs_function[] = {
 210         /* CDC ECM control descriptors */
 211         (struct usb_descriptor_header *) &ecm_control_intf,
 212         (struct usb_descriptor_header *) &ecm_header_desc,
 213         (struct usb_descriptor_header *) &ecm_union_desc,
 214         (struct usb_descriptor_header *) &ecm_desc,
 215
 216         /* NOTE: status endpoint might need to be removed */
 217         (struct usb_descriptor_header *) &fs_ecm_notify_desc,
 218
 219         /* data interface, altsettings 0 and 1 */
 220         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 221         (struct usb_descriptor_header *) &ecm_data_intf,
 222         (struct usb_descriptor_header *) &fs_ecm_in_desc,
 223         (struct usb_descriptor_header *) &fs_ecm_out_desc,
 224         NULL,
 225 };
 226
 227 /* high speed support: */
 228
 229 static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
 230         .bLength =              USB_DT_ENDPOINT_SIZE,
 231         .bDescriptorType =      USB_DT_ENDPOINT,
 232
 233         .bEndpointAddress =     USB_DIR_IN,
 234         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 235         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 236         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 237 };
 238
 239 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
 240         .bLength =              USB_DT_ENDPOINT_SIZE,
 241         .bDescriptorType =      USB_DT_ENDPOINT,
 242
 243         .bEndpointAddress =     USB_DIR_IN,
 244         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 245         .wMaxPacketSize =       cpu_to_le16(512),
 246 };
 247
 248 static struct usb_endpoint_descriptor hs_ecm_out_desc = {
 249         .bLength =              USB_DT_ENDPOINT_SIZE,
 250         .bDescriptorType =      USB_DT_ENDPOINT,
 251
 252         .bEndpointAddress =     USB_DIR_OUT,
 253         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 254         .wMaxPacketSize =       cpu_to_le16(512),
 255 };
 256
 257 static struct usb_descriptor_header *ecm_hs_function[] = {
 258         /* CDC ECM control descriptors */
 259         (struct usb_descriptor_header *) &ecm_control_intf,
 260         (struct usb_descriptor_header *) &ecm_header_desc,
 261         (struct usb_descriptor_header *) &ecm_union_desc,
 262         (struct usb_descriptor_header *) &ecm_desc,
 263
 264         /* NOTE: status endpoint might need to be removed */
 265         (struct usb_descriptor_header *) &hs_ecm_notify_desc,
 266
 267         /* data interface, altsettings 0 and 1 */
 268         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 269         (struct usb_descriptor_header *) &ecm_data_intf,
 270         (struct usb_descriptor_header *) &hs_ecm_in_desc,
 271         (struct usb_descriptor_header *) &hs_ecm_out_desc,
 272         NULL,
 273 };
 274
 275 /* super speed support: */
 276
 277 static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
 278         .bLength =              USB_DT_ENDPOINT_SIZE,
 279         .bDescriptorType =      USB_DT_ENDPOINT,
 280
 281         .bEndpointAddress =     USB_DIR_IN,
 282         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 283         .wMaxPacketSize =       cpu_to_le16(ECM_STATUS_BYTECOUNT),
 284         .bInterval =            LOG2_STATUS_INTERVAL_MSEC + 4,
 285 };
 286
 287 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
 288         .bLength =              sizeof ss_ecm_intr_comp_desc,
 289         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 290
 291         /* the following 3 values can be tweaked if necessary */
 292         /* .bMaxBurst =         0, */
 293         /* .bmAttributes =      0, */
 294         .wBytesPerInterval =    cpu_to_le16(ECM_STATUS_BYTECOUNT),
 295 };
 296
 297 static struct usb_endpoint_descriptor ss_ecm_in_desc = {
 298         .bLength =              USB_DT_ENDPOINT_SIZE,
 299         .bDescriptorType =      USB_DT_ENDPOINT,
 300
 301         .bEndpointAddress =     USB_DIR_IN,
 302         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 303         .wMaxPacketSize =       cpu_to_le16(1024),
 304 };
 305
 306 static struct usb_endpoint_descriptor ss_ecm_out_desc = {
 307         .bLength =              USB_DT_ENDPOINT_SIZE,
 308         .bDescriptorType =      USB_DT_ENDPOINT,
 309
 310         .bEndpointAddress =     USB_DIR_OUT,
 311         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 312         .wMaxPacketSize =       cpu_to_le16(1024),
 313 };
 314
 315 static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
 316         .bLength =              sizeof ss_ecm_bulk_comp_desc,
 317         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 318
 319         /* the following 2 values can be tweaked if necessary */
 320         /* .bMaxBurst =         0, */
 321         /* .bmAttributes =      0, */
 322 };
 323
 324 static struct usb_descriptor_header *ecm_ss_function[] = {
 325         /* CDC ECM control descriptors */
 326         (struct usb_descriptor_header *) &ecm_control_intf,
 327         (struct usb_descriptor_header *) &ecm_header_desc,
 328         (struct usb_descriptor_header *) &ecm_union_desc,
 329         (struct usb_descriptor_header *) &ecm_desc,
 330
 331         /* NOTE: status endpoint might need to be removed */
 332         (struct usb_descriptor_header *) &ss_ecm_notify_desc,
 333         (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
 334
 335         /* data interface, altsettings 0 and 1 */
 336         (struct usb_descriptor_header *) &ecm_data_nop_intf,
 337         (struct usb_descriptor_header *) &ecm_data_intf,
 338         (struct usb_descriptor_header *) &ss_ecm_in_desc,
 339         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 340         (struct usb_descriptor_header *) &ss_ecm_out_desc,
 341         (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
 342         NULL,
 343 };
 344
 345 /* string descriptors: */
 346
 347 static struct usb_string ecm_string_defs[] = {
 348         [0].s = "CDC Ethernet Control Model (ECM)",
 349         [1].s = NULL /* DYNAMIC */,
 350         [2].s = "CDC Ethernet Data",
 351         {  } /* end of list */
 352 };
 353
 354 static struct usb_gadget_strings ecm_string_table = {
 355         .language =             0x0409, /* en-us */
 356         .strings =              ecm_string_defs,
 357 };
 358
 359 static struct usb_gadget_strings *ecm_strings[] = {
 360         &ecm_string_table,
 361         NULL,
 362 };
 363
 364 /*-------------------------------------------------------------------------*/
 365
 366 static void ecm_do_notify(struct f_ecm *ecm)
 367 {
 368         struct usb_request              *req = ecm->notify_req;
 369         struct usb_cdc_notification     *event;
 370         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 371         __le32                          *data;
 372         int                             status;
 373
 374         /* notification already in flight? */
 375         if (!req)
 376                 return;
 377
 378         event = req->buf;
 379         switch (ecm->notify_state) {
 380         case ECM_NOTIFY_NONE:
 381                 return;
 382
 383         case ECM_NOTIFY_CONNECT:
 384                 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 385                 if (ecm->is_open)
 386                         event->wValue = cpu_to_le16(1);
 387                 else
 388                         event->wValue = cpu_to_le16(0);
 389                 event->wLength = 0;
 390                 req->length = sizeof *event;
 391
 392                 DBG(cdev, "notify connect %s\n",
 393                                 ecm->is_open ? "true" : "false");
 394                 ecm->notify_state = ECM_NOTIFY_SPEED;
 395                 break;
 396
 397         case ECM_NOTIFY_SPEED:
 398                 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 399                 event->wValue = cpu_to_le16(0);
 400                 event->wLength = cpu_to_le16(8);
 401                 req->length = ECM_STATUS_BYTECOUNT;
 402
 403                 /* SPEED_CHANGE data is up/down speeds in bits/sec */
 404                 data = req->buf + sizeof *event;
 405                 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
 406                 data[1] = data[0];
 407
 408                 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
 409                 ecm->notify_state = ECM_NOTIFY_NONE;
 410                 break;
 411         }
 412         event->bmRequestType = 0xA1;
 413         event->wIndex = cpu_to_le16(ecm->ctrl_id);
 414
 415         ecm->notify_req = NULL;
 416         status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
 417         if (status < 0) {
 418                 ecm->notify_req = req;
 419                 DBG(cdev, "notify --> %d\n", status);
 420         }
 421 }
 422
 423 static void ecm_notify(struct f_ecm *ecm)
 424 {
 425         /* NOTE on most versions of Linux, host side cdc-ethernet
 426          * won't listen for notifications until its netdevice opens.
 427          * The first notification then sits in the FIFO for a long
 428          * time, and the second one is queued.
 429          */
 430         ecm->notify_state = ECM_NOTIFY_CONNECT;
 431         ecm_do_notify(ecm);
 432 }
 433
 434 static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 435 {
 436         struct f_ecm                    *ecm = req->context;
 437         struct usb_composite_dev        *cdev = ecm->port.func.config->cdev;
 438         struct usb_cdc_notification     *event = req->buf;
 439
 440         switch (req->status) {
 441         case 0:
 442                 /* no fault */
 443                 break;
 444         case -ECONNRESET:
 445         case -ESHUTDOWN:
 446                 ecm->notify_state = ECM_NOTIFY_NONE;
 447                 break;
 448         default:
 449                 DBG(cdev, "event %02x --> %d\n",
 450                         event->bNotificationType, req->status);
 451                 break;
 452         }
 453         ecm->notify_req = req;
 454         ecm_do_notify(ecm);
 455 }
 456
 457 static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 458 {
 459         struct f_ecm            *ecm = func_to_ecm(f);
 460         struct usb_composite_dev *cdev = f->config->cdev;
 461         struct usb_request      *req = cdev->req;
 462         int                     value = -EOPNOTSUPP;
 463         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 464         u16                     w_value = le16_to_cpu(ctrl->wValue);
 465         u16                     w_length = le16_to_cpu(ctrl->wLength);
 466
 467         /* composite driver infrastructure handles everything except
 468          * CDC class messages; interface activation uses set_alt().
 469          */
 470         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 471         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 472                         | USB_CDC_SET_ETHERNET_PACKET_FILTER:
 473                 /* see 6.2.30: no data, wIndex = interface,
 474                  * wValue = packet filter bitmap
 475                  */
 476                 if (w_length != 0 || w_index != ecm->ctrl_id)
 477                         goto invalid;
 478                 DBG(cdev, "packet filter %02x\n", w_value);
 479                 /* REVISIT locking of cdc_filter.  This assumes the UDC
 480                  * driver won't have a concurrent packet TX irq running on
 481                  * another CPU; or that if it does, this write is atomic...
 482                  */
 483                 ecm->port.cdc_filter = w_value;
 484                 value = 0;
 485                 break;
 486
 487         /* and optionally:
 488          * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 489          * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 490          * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 491          * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 492          * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 493          * case USB_CDC_GET_ETHERNET_STATISTIC:
 494          */
 495
 496         default:
 497 invalid:
 498                 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 499                         ctrl->bRequestType, ctrl->bRequest,
 500                         w_value, w_index, w_length);
 501         }
 502
 503         /* respond with data transfer or status phase? */
 504         if (value >= 0) {
 505                 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
 506                         ctrl->bRequestType, ctrl->bRequest,
 507                         w_value, w_index, w_length);
 508                 req->zero = 0;
 509                 req->length = value;
 510                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 511                 if (value < 0)
 512                         ERROR(cdev, "ecm req %02x.%02x response err %d\n",
 513                                         ctrl->bRequestType, ctrl->bRequest,
 514                                         value);
 515         }
 516
 517         /* device either stalls (value < 0) or reports success */
 518         return value;
 519 }
 520
 521
 522 static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 523 {
 524         struct f_ecm            *ecm = func_to_ecm(f);
 525         struct usb_composite_dev *cdev = f->config->cdev;
 526
 527         /* Control interface has only altsetting 0 */
 528         if (intf == ecm->ctrl_id) {
 529                 if (alt != 0)
 530                         goto fail;
 531
 532                 if (ecm->notify->driver_data) {
 533                         VDBG(cdev, "reset ecm control %d\n", intf);
 534                         usb_ep_disable(ecm->notify);
 535                 }
 536                 if (!(ecm->notify->desc)) {
 537                         VDBG(cdev, "init ecm ctrl %d\n", intf);
 538                         if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 539                                 goto fail;
 540                 }
 541                 usb_ep_enable(ecm->notify);
 542                 ecm->notify->driver_data = ecm;
 543
 544         /* Data interface has two altsettings, 0 and 1 */
 545         } else if (intf == ecm->data_id) {
 546                 if (alt > 1)
 547                         goto fail;
 548
 549                 if (ecm->port.in_ep->driver_data) {
 550                         DBG(cdev, "reset ecm\n");
 551                         gether_disconnect(&ecm->port);
 552                 }
 553
 554                 if (!ecm->port.in_ep->desc ||
 555                     !ecm->port.out_ep->desc) {
 556                         DBG(cdev, "init ecm\n");
 557                         if (config_ep_by_speed(cdev->gadget, f,
 558                                                ecm->port.in_ep) ||
 559                             config_ep_by_speed(cdev->gadget, f,
 560                                                ecm->port.out_ep)) {
 561                                 ecm->port.in_ep->desc = NULL;
 562                                 ecm->port.out_ep->desc = NULL;
 563                                 goto fail;
 564                         }
 565                 }
 566
 567                 /* CDC Ethernet only sends data in non-default altsettings.
 568                  * Changing altsettings resets filters, statistics, etc.
 569                  */
 570                 if (alt == 1) {
 571                         struct net_device       *net;
 572
 573                         /* Enable zlps by default for ECM conformance;
 574                          * override for musb_hdrc (avoids txdma ovhead).
 575                          */
 576                         ecm->port.is_zlp_ok = !(gadget_is_musbhdrc(cdev->gadget)
 577                                 );
 578                         ecm->port.cdc_filter = DEFAULT_FILTER;
 579                         DBG(cdev, "activate ecm\n");
 580                         net = gether_connect(&ecm->port);
 581                         if (IS_ERR(net))
 582                                 return PTR_ERR(net);
 583                 }
 584
 585                 /* NOTE this can be a minor disagreement with the ECM spec,
 586                  * which says speed notifications will "always" follow
 587                  * connection notifications.  But we allow one connect to
 588                  * follow another (if the first is in flight), and instead
 589                  * just guarantee that a speed notification is always sent.
 590                  */
 591                 ecm_notify(ecm);
 592         } else
 593                 goto fail;
 594
 595         return 0;
 596 fail:
 597         return -EINVAL;
 598 }
 599
 600 /* Because the data interface supports multiple altsettings,
 601  * this ECM function *MUST* implement a get_alt() method.
 602  */
 603 static int ecm_get_alt(struct usb_function *f, unsigned intf)
 604 {
 605         struct f_ecm            *ecm = func_to_ecm(f);
 606
 607         if (intf == ecm->ctrl_id)
 608                 return 0;
 609         return ecm->port.in_ep->driver_data ? 1 : 0;
 610 }
 611
 612 static void ecm_disable(struct usb_function *f)
 613 {
 614         struct f_ecm            *ecm = func_to_ecm(f);
 615         struct usb_composite_dev *cdev = f->config->cdev;
 616
 617         DBG(cdev, "ecm deactivated\n");
 618
 619         if (ecm->port.in_ep->driver_data)
 620                 gether_disconnect(&ecm->port);
 621
 622         if (ecm->notify->driver_data) {
 623                 usb_ep_disable(ecm->notify);
 624                 ecm->notify->driver_data = NULL;
 625                 ecm->notify->desc = NULL;
 626         }
 627 }
 628
 629 /*-------------------------------------------------------------------------*/
 630
 631 /*
 632  * Callbacks let us notify the host about connect/disconnect when the
 633  * net device is opened or closed.
 634  *
 635  * For testing, note that link states on this side include both opened
 636  * and closed variants of:
 637  *
 638  *   - disconnected/unconfigured
 639  *   - configured but inactive (data alt 0)
 640  *   - configured and active (data alt 1)
 641  *
 642  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
 643  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
 644  * imply the host is actually polling the notification endpoint, and
 645  * likewise that "active" doesn't imply it's actually using the data
 646  * endpoints for traffic.
 647  */
 648
 649 static void ecm_open(struct gether *geth)
 650 {
 651         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 652
 653         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 654
 655         ecm->is_open = true;
 656         ecm_notify(ecm);
 657 }
 658
 659 static void ecm_close(struct gether *geth)
 660 {
 661         struct f_ecm            *ecm = func_to_ecm(&geth->func);
 662
 663         DBG(ecm->port.func.config->cdev, "%s\n", __func__);
 664
 665         ecm->is_open = false;
 666         ecm_notify(ecm);
 667 }
 668
 669 /*-------------------------------------------------------------------------*/
 670
 671 /* ethernet function driver setup/binding */
 672
 673 static int
 674 ecm_bind(struct usb_configuration *c, struct usb_function *f)
 675 {
 676         struct usb_composite_dev *cdev = c->cdev;
 677         struct f_ecm            *ecm = func_to_ecm(f);
 678         int                     status;
 679         struct usb_ep           *ep;
 680
 681         /* allocate instance-specific interface IDs */
 682         status = usb_interface_id(c, f);
 683         if (status < 0)
 684                 goto fail;
 685         ecm->ctrl_id = status;
 686
 687         ecm_control_intf.bInterfaceNumber = status;
 688         ecm_union_desc.bMasterInterface0 = status;
 689
 690         status = usb_interface_id(c, f);
 691         if (status < 0)
 692                 goto fail;
 693         ecm->data_id = status;
 694
 695         ecm_data_nop_intf.bInterfaceNumber = status;
 696         ecm_data_intf.bInterfaceNumber = status;
 697         ecm_union_desc.bSlaveInterface0 = status;
 698
 699         status = -ENODEV;
 700
 701         /* allocate instance-specific endpoints */
 702         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
 703         if (!ep)
 704                 goto fail;
 705         ecm->port.in_ep = ep;
 706         ep->driver_data = cdev; /* claim */
 707
 708         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 709         if (!ep)
 710                 goto fail;
 711         ecm->port.out_ep = ep;
 712         ep->driver_data = cdev; /* claim */
 713
 714         /* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 715          * don't treat it that way.  It's simpler, and some newer CDC
 716          * profiles (wireless handsets) no longer treat it as optional.
 717          */
 718         ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
 719         if (!ep)
 720                 goto fail;
 721         ecm->notify = ep;
 722         ep->driver_data = cdev; /* claim */
 723
 724         status = -ENOMEM;
 725
 726         /* allocate notification request and buffer */
 727         ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 728         if (!ecm->notify_req)
 729                 goto fail;
 730         ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
 731         if (!ecm->notify_req->buf)
 732                 goto fail;
 733         ecm->notify_req->context = ecm;
 734         ecm->notify_req->complete = ecm_notify_complete;
 735
 736         /* copy descriptors, and track endpoint copies */
 737         f->descriptors = usb_copy_descriptors(ecm_fs_function);
 738         if (!f->descriptors)
 739                 goto fail;
 740
 741         /* support all relevant hardware speeds... we expect that when
 742          * hardware is dual speed, all bulk-capable endpoints work at
 743          * both speeds
 744          */
 745         if (gadget_is_dualspeed(c->cdev->gadget)) {
 746                 hs_ecm_in_desc.bEndpointAddress =
 747                                 fs_ecm_in_desc.bEndpointAddress;
 748                 hs_ecm_out_desc.bEndpointAddress =
 749                                 fs_ecm_out_desc.bEndpointAddress;
 750                 hs_ecm_notify_desc.bEndpointAddress =
 751                                 fs_ecm_notify_desc.bEndpointAddress;
 752
 753                 /* copy descriptors, and track endpoint copies */
 754                 f->hs_descriptors = usb_copy_descriptors(ecm_hs_function);
 755                 if (!f->hs_descriptors)
 756                         goto fail;
 757         }
 758
 759         if (gadget_is_superspeed(c->cdev->gadget)) {
 760                 ss_ecm_in_desc.bEndpointAddress =
 761                                 fs_ecm_in_desc.bEndpointAddress;
 762                 ss_ecm_out_desc.bEndpointAddress =
 763                                 fs_ecm_out_desc.bEndpointAddress;
 764                 ss_ecm_notify_desc.bEndpointAddress =
 765                                 fs_ecm_notify_desc.bEndpointAddress;
 766
 767                 /* copy descriptors, and track endpoint copies */
 768                 f->ss_descriptors = usb_copy_descriptors(ecm_ss_function);
 769                 if (!f->ss_descriptors)
 770                         goto fail;
 771         }
 772
 773         /* NOTE:  all that is done without knowing or caring about
 774          * the network link ... which is unavailable to this code
 775          * until we're activated via set_alt().
 776          */
 777
 778         ecm->port.open = ecm_open;
 779         ecm->port.close = ecm_close;
 780
 781         DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 782                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 783                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 784                         ecm->port.in_ep->name, ecm->port.out_ep->name,
 785                         ecm->notify->name);
 786         return 0;
 787
 788 fail:
 789         if (f->descriptors)
 790                 usb_free_descriptors(f->descriptors);
 791         if (f->hs_descriptors)
 792                 usb_free_descriptors(f->hs_descriptors);
 793
 794         if (ecm->notify_req) {
 795                 kfree(ecm->notify_req->buf);
 796                 usb_ep_free_request(ecm->notify, ecm->notify_req);
 797         }
 798
 799         /* we might as well release our claims on endpoints */
 800         if (ecm->notify)
 801                 ecm->notify->driver_data = NULL;
 802         if (ecm->port.out_ep->desc)
 803                 ecm->port.out_ep->driver_data = NULL;
 804         if (ecm->port.in_ep->desc)
 805                 ecm->port.in_ep->driver_data = NULL;
 806
 807         ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 808
 809         return status;
 810 }
 811
 812 static void
 813 ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 814 {
 815         struct f_ecm            *ecm = func_to_ecm(f);
 816
 817         DBG(c->cdev, "ecm unbind\n");
 818
 819         if (gadget_is_superspeed(c->cdev->gadget))
 820                 usb_free_descriptors(f->ss_descriptors);
 821         if (gadget_is_dualspeed(c->cdev->gadget))
 822                 usb_free_descriptors(f->hs_descriptors);
 823         usb_free_descriptors(f->descriptors);
 824
 825         kfree(ecm->notify_req->buf);
 826         usb_ep_free_request(ecm->notify, ecm->notify_req);
 827
 828         ecm_string_defs[1].s = NULL;
 829         kfree(ecm);
 830 }
 831
 832 /**
 833  * ecm_bind_config - add CDC Ethernet network link to a configuration
 834  * @c: the configuration to support the network link
 835  * @ethaddr: a buffer in which the ethernet address of the host side
 836  *      side of the link was recorded
 837  * Context: single threaded during gadget setup
 838  *
 839  * Returns zero on success, else negative errno.
 840  *
 841  * Caller must have called @gether_setup().  Caller is also responsible
 842  * for calling @gether_cleanup() before module unload.
 843  */
 844 int
 845 ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 846 {
 847         struct f_ecm    *ecm;
 848         int             status;
 849
 850         if (!can_support_ecm(c->cdev->gadget) || !ethaddr)
 851                 return -EINVAL;
 852
 853         /* maybe allocate device-global string IDs */
 854         if (ecm_string_defs[0].id == 0) {
 855
 856                 /* control interface label */
 857                 status = usb_string_id(c->cdev);
 858                 if (status < 0)
 859                         return status;
 860                 ecm_string_defs[0].id = status;
 861                 ecm_control_intf.iInterface = status;
 862
 863                 /* data interface label */
 864                 status = usb_string_id(c->cdev);
 865                 if (status < 0)
 866                         return status;
 867                 ecm_string_defs[2].id = status;
 868                 ecm_data_intf.iInterface = status;
 869
 870                 /* MAC address */
 871                 status = usb_string_id(c->cdev);
 872                 if (status < 0)
 873                         return status;
 874                 ecm_string_defs[1].id = status;
 875                 ecm_desc.iMACAddress = status;
 876         }
 877
 878         /* allocate and initialize one new instance */
 879         ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
 880         if (!ecm)
 881                 return -ENOMEM;
 882
 883         /* export host's Ethernet address in CDC format */
 884         snprintf(ecm->ethaddr, sizeof ecm->ethaddr,
 885                 "%02X%02X%02X%02X%02X%02X",
 886                 ethaddr[0], ethaddr[1], ethaddr[2],
 887                 ethaddr[3], ethaddr[4], ethaddr[5]);
 888         ecm_string_defs[1].s = ecm->ethaddr;
 889
 890         ecm->port.cdc_filter = DEFAULT_FILTER;
 891
 892         ecm->port.func.name = "cdc_ethernet";
 893         ecm->port.func.strings = ecm_strings;
 894         /* descriptors are per-instance copies */
 895         ecm->port.func.bind = ecm_bind;
 896         ecm->port.func.unbind = ecm_unbind;
 897         ecm->port.func.set_alt = ecm_set_alt;
 898         ecm->port.func.get_alt = ecm_get_alt;
 899         ecm->port.func.setup = ecm_setup;
 900         ecm->port.func.disable = ecm_disable;
 901
 902         status = usb_add_function(c, &ecm->port.func);
 903         if (status) {
 904                 ecm_string_defs[1].s = NULL;
 905                 kfree(ecm);
 906         }
 907         return status;
 908 }