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