drivers/usb/gadget/ether.c

   1 /*
   2  * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
   3  *
   4  * Copyright (C) 2003-2005,2008 David Brownell
   5  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
   6  * Copyright (C) 2008 Nokia Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 /* #define VERBOSE_DEBUG */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/netdevice.h>
  18
  19 #if defined USB_ETH_RNDIS
  20 #  undef USB_ETH_RNDIS
  21 #endif
  22 #ifdef CONFIG_USB_ETH_RNDIS
  23 #  define USB_ETH_RNDIS y
  24 #endif
  25
  26 #include "u_ether.h"
  27
  28
  29 /*
  30  * Ethernet gadget driver -- with CDC and non-CDC options
  31  * Builds on hardware support for a full duplex link.
  32  *
  33  * CDC Ethernet is the standard USB solution for sending Ethernet frames
  34  * using USB.  Real hardware tends to use the same framing protocol but look
  35  * different for control features.  This driver strongly prefers to use
  36  * this USB-IF standard as its open-systems interoperability solution;
  37  * most host side USB stacks (except from Microsoft) support it.
  38  *
  39  * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
  40  * TLA-soup.  "CDC ACM" (Abstract Control Model) is for modems, and a new
  41  * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
  42  *
  43  * There's some hardware that can't talk CDC ECM.  We make that hardware
  44  * implement a "minimalist" vendor-agnostic CDC core:  same framing, but
  45  * link-level setup only requires activating the configuration.  Only the
  46  * endpoint descriptors, and product/vendor IDs, are relevant; no control
  47  * operations are available.  Linux supports it, but other host operating
  48  * systems may not.  (This is a subset of CDC Ethernet.)
  49  *
  50  * It turns out that if you add a few descriptors to that "CDC Subset",
  51  * (Windows) host side drivers from MCCI can treat it as one submode of
  52  * a proprietary scheme called "SAFE" ... without needing to know about
  53  * specific product/vendor IDs.  So we do that, making it easier to use
  54  * those MS-Windows drivers.  Those added descriptors make it resemble a
  55  * CDC MDLM device, but they don't change device behavior at all.  (See
  56  * MCCI Engineering report 950198 "SAFE Networking Functions".)
  57  *
  58  * A third option is also in use.  Rather than CDC Ethernet, or something
  59  * simpler, Microsoft pushes their own approach: RNDIS.  The published
  60  * RNDIS specs are ambiguous and appear to be incomplete, and are also
  61  * needlessly complex.  They borrow more from CDC ACM than CDC ECM.
  62  */
  63
  64 #define DRIVER_DESC             "Ethernet Gadget"
  65 #define DRIVER_VERSION          "Memorial Day 2008"
  66
  67 #ifdef USB_ETH_RNDIS
  68 #define PREFIX                  "RNDIS/"
  69 #else
  70 #define PREFIX                  ""
  71 #endif
  72
  73 /*
  74  * This driver aims for interoperability by using CDC ECM unless
  75  *
  76  *              can_support_ecm()
  77  *
  78  * returns false, in which case it supports the CDC Subset.  By default,
  79  * that returns true; most hardware has no problems with CDC ECM, that's
  80  * a good default.  Previous versions of this driver had no default; this
  81  * version changes that, removing overhead for new controller support.
  82  *
  83  *      IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
  84  */
  85
  86 static inline bool has_rndis(void)
  87 {
  88 #ifdef  USB_ETH_RNDIS
  89         return true;
  90 #else
  91         return false;
  92 #endif
  93 }
  94
  95 #include <linux/module.h>
  96
  97 #include "u_ecm.h"
  98 #include "u_gether.h"
  99 #ifdef  USB_ETH_RNDIS
 100 #include "u_rndis.h"
 101 #include "rndis.h"
 102 #else
 103 #define rndis_borrow_net(...) do {} while (0)
 104 #endif
 105 #include "u_eem.h"
 106
 107 /*-------------------------------------------------------------------------*/
 108 USB_GADGET_COMPOSITE_OPTIONS();
 109
 110 USB_ETHERNET_MODULE_PARAMETERS();
 111
 112 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 113  * Instead:  allocate your own, using normal USB-IF procedures.
 114  */
 115
 116 /* Thanks to NetChip Technologies for donating this product ID.
 117  * It's for devices with only CDC Ethernet configurations.
 118  */
 119 #define CDC_VENDOR_NUM          0x0525  /* NetChip */
 120 #define CDC_PRODUCT_NUM         0xa4a1  /* Linux-USB Ethernet Gadget */
 121
 122 /* For hardware that can't talk CDC, we use the same vendor ID that
 123  * ARM Linux has used for ethernet-over-usb, both with sa1100 and
 124  * with pxa250.  We're protocol-compatible, if the host-side drivers
 125  * use the endpoint descriptors.  bcdDevice (version) is nonzero, so
 126  * drivers that need to hard-wire endpoint numbers have a hook.
 127  *
 128  * The protocol is a minimal subset of CDC Ether, which works on any bulk
 129  * hardware that's not deeply broken ... even on hardware that can't talk
 130  * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
 131  * doesn't handle control-OUT).
 132  */
 133 #define SIMPLE_VENDOR_NUM       0x049f
 134 #define SIMPLE_PRODUCT_NUM      0x505a
 135
 136 /* For hardware that can talk RNDIS and either of the above protocols,
 137  * use this ID ... the windows INF files will know it.  Unless it's
 138  * used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
 139  * the non-RNDIS configuration.
 140  */
 141 #define RNDIS_VENDOR_NUM        0x0525  /* NetChip */
 142 #define RNDIS_PRODUCT_NUM       0xa4a2  /* Ethernet/RNDIS Gadget */
 143
 144 /* For EEM gadgets */
 145 #define EEM_VENDOR_NUM          0x1d6b  /* Linux Foundation */
 146 #define EEM_PRODUCT_NUM         0x0102  /* EEM Gadget */
 147
 148 /*-------------------------------------------------------------------------*/
 149
 150 static struct usb_device_descriptor device_desc = {
 151         .bLength =              sizeof device_desc,
 152         .bDescriptorType =      USB_DT_DEVICE,
 153
 154         .bcdUSB =               cpu_to_le16 (0x0200),
 155
 156         .bDeviceClass =         USB_CLASS_COMM,
 157         .bDeviceSubClass =      0,
 158         .bDeviceProtocol =      0,
 159         /* .bMaxPacketSize0 = f(hardware) */
 160
 161         /* Vendor and product id defaults change according to what configs
 162          * we support.  (As does bNumConfigurations.)  These values can
 163          * also be overridden by module parameters.
 164          */
 165         .idVendor =             cpu_to_le16 (CDC_VENDOR_NUM),
 166         .idProduct =            cpu_to_le16 (CDC_PRODUCT_NUM),
 167         /* .bcdDevice = f(hardware) */
 168         /* .iManufacturer = DYNAMIC */
 169         /* .iProduct = DYNAMIC */
 170         /* NO SERIAL NUMBER */
 171         .bNumConfigurations =   1,
 172 };
 173
 174 static struct usb_otg_descriptor otg_descriptor = {
 175         .bLength =              sizeof otg_descriptor,
 176         .bDescriptorType =      USB_DT_OTG,
 177
 178         /* REVISIT SRP-only hardware is possible, although
 179          * it would not be called "OTG" ...
 180          */
 181         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 182 };
 183
 184 static const struct usb_descriptor_header *otg_desc[] = {
 185         (struct usb_descriptor_header *) &otg_descriptor,
 186         NULL,
 187 };
 188
 189 static struct usb_string strings_dev[] = {
 190         [USB_GADGET_MANUFACTURER_IDX].s = "",
 191         [USB_GADGET_PRODUCT_IDX].s = PREFIX DRIVER_DESC,
 192         [USB_GADGET_SERIAL_IDX].s = "",
 193         {  } /* end of list */
 194 };
 195
 196 static struct usb_gadget_strings stringtab_dev = {
 197         .language       = 0x0409,       /* en-us */
 198         .strings        = strings_dev,
 199 };
 200
 201 static struct usb_gadget_strings *dev_strings[] = {
 202         &stringtab_dev,
 203         NULL,
 204 };
 205
 206 static struct usb_function_instance *fi_ecm;
 207 static struct usb_function *f_ecm;
 208
 209 static struct usb_function_instance *fi_eem;
 210 static struct usb_function *f_eem;
 211
 212 static struct usb_function_instance *fi_geth;
 213 static struct usb_function *f_geth;
 214
 215 static struct usb_function_instance *fi_rndis;
 216 static struct usb_function *f_rndis;
 217
 218 /*-------------------------------------------------------------------------*/
 219
 220 /*
 221  * We may not have an RNDIS configuration, but if we do it needs to be
 222  * the first one present.  That's to make Microsoft's drivers happy,
 223  * and to follow DOCSIS 1.0 (cable modem standard).
 224  */
 225 static int __init rndis_do_config(struct usb_configuration *c)
 226 {
 227         int status;
 228
 229         /* FIXME alloc iConfiguration string, set it in c->strings */
 230
 231         if (gadget_is_otg(c->cdev->gadget)) {
 232                 c->descriptors = otg_desc;
 233                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 234         }
 235
 236         f_rndis = usb_get_function(fi_rndis);
 237         if (IS_ERR(f_rndis))
 238                 return PTR_ERR(f_rndis);
 239
 240         status = usb_add_function(c, f_rndis);
 241         if (status < 0)
 242                 usb_put_function(f_rndis);
 243
 244         return status;
 245 }
 246
 247 static struct usb_configuration rndis_config_driver = {
 248         .label                  = "RNDIS",
 249         .bConfigurationValue    = 2,
 250         /* .iConfiguration = DYNAMIC */
 251         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 252 };
 253
 254 /*-------------------------------------------------------------------------*/
 255
 256 #ifdef CONFIG_USB_ETH_EEM
 257 static bool use_eem = 1;
 258 #else
 259 static bool use_eem;
 260 #endif
 261 module_param(use_eem, bool, 0);
 262 MODULE_PARM_DESC(use_eem, "use CDC EEM mode");
 263
 264 /*
 265  * We _always_ have an ECM, CDC Subset, or EEM configuration.
 266  */
 267 static int __init eth_do_config(struct usb_configuration *c)
 268 {
 269         int status = 0;
 270
 271         /* FIXME alloc iConfiguration string, set it in c->strings */
 272
 273         if (gadget_is_otg(c->cdev->gadget)) {
 274                 c->descriptors = otg_desc;
 275                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 276         }
 277
 278         if (use_eem) {
 279                 f_eem = usb_get_function(fi_eem);
 280                 if (IS_ERR(f_eem))
 281                         return PTR_ERR(f_eem);
 282
 283                 status = usb_add_function(c, f_eem);
 284                 if (status < 0)
 285                         usb_put_function(f_eem);
 286
 287                 return status;
 288         } else if (can_support_ecm(c->cdev->gadget)) {
 289                 f_ecm = usb_get_function(fi_ecm);
 290                 if (IS_ERR(f_ecm))
 291                         return PTR_ERR(f_ecm);
 292
 293                 status = usb_add_function(c, f_ecm);
 294                 if (status < 0)
 295                         usb_put_function(f_ecm);
 296
 297                 return status;
 298         } else {
 299                 f_geth = usb_get_function(fi_geth);
 300                 if (IS_ERR(f_geth))
 301                         return PTR_ERR(f_geth);
 302
 303                 status = usb_add_function(c, f_geth);
 304                 if (status < 0)
 305                         usb_put_function(f_geth);
 306
 307                 return status;
 308         }
 309
 310 }
 311
 312 static struct usb_configuration eth_config_driver = {
 313         /* .label = f(hardware) */
 314         .bConfigurationValue    = 1,
 315         /* .iConfiguration = DYNAMIC */
 316         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 317 };
 318
 319 /*-------------------------------------------------------------------------*/
 320
 321 static int __init eth_bind(struct usb_composite_dev *cdev)
 322 {
 323         struct usb_gadget       *gadget = cdev->gadget;
 324         struct f_eem_opts       *eem_opts = NULL;
 325         struct f_ecm_opts       *ecm_opts = NULL;
 326         struct f_gether_opts    *geth_opts = NULL;
 327         struct net_device       *net;
 328         int                     status;
 329
 330         /* set up main config label and device descriptor */
 331         if (use_eem) {
 332                 /* EEM */
 333                 fi_eem = usb_get_function_instance("eem");
 334                 if (IS_ERR(fi_eem))
 335                         return PTR_ERR(fi_eem);
 336
 337                 eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst);
 338
 339                 net = eem_opts->net;
 340
 341                 eth_config_driver.label = "CDC Ethernet (EEM)";
 342                 device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM);
 343                 device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM);
 344         } else if (can_support_ecm(gadget)) {
 345                 /* ECM */
 346
 347                 fi_ecm = usb_get_function_instance("ecm");
 348                 if (IS_ERR(fi_ecm))
 349                         return PTR_ERR(fi_ecm);
 350
 351                 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
 352
 353                 net = ecm_opts->net;
 354
 355                 eth_config_driver.label = "CDC Ethernet (ECM)";
 356         } else {
 357                 /* CDC Subset */
 358
 359                 fi_geth = usb_get_function_instance("geth");
 360                 if (IS_ERR(fi_geth))
 361                         return PTR_ERR(fi_geth);
 362
 363                 geth_opts = container_of(fi_geth, struct f_gether_opts,
 364                                          func_inst);
 365
 366                 net = geth_opts->net;
 367
 368                 eth_config_driver.label = "CDC Subset/SAFE";
 369
 370                 device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM);
 371                 device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM);
 372                 if (!has_rndis())
 373                         device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 374         }
 375
 376         gether_set_qmult(net, qmult);
 377         if (!gether_set_host_addr(net, host_addr))
 378                 pr_info("using host ethernet address: %s", host_addr);
 379         if (!gether_set_dev_addr(net, dev_addr))
 380                 pr_info("using self ethernet address: %s", dev_addr);
 381
 382         if (has_rndis()) {
 383                 /* RNDIS plus ECM-or-Subset */
 384                 gether_set_gadget(net, cdev->gadget);
 385                 status = gether_register_netdev(net);
 386                 if (status)
 387                         goto fail;
 388
 389                 if (use_eem)
 390                         eem_opts->bound = true;
 391                 else if (can_support_ecm(gadget))
 392                         ecm_opts->bound = true;
 393                 else
 394                         geth_opts->bound = true;
 395
 396                 fi_rndis = usb_get_function_instance("rndis");
 397                 if (IS_ERR(fi_rndis)) {
 398                         status = PTR_ERR(fi_rndis);
 399                         goto fail;
 400                 }
 401
 402                 rndis_borrow_net(fi_rndis, net);
 403
 404                 device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM);
 405                 device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM);
 406                 device_desc.bNumConfigurations = 2;
 407         }
 408
 409         /* Allocate string descriptor numbers ... note that string
 410          * contents can be overridden by the composite_dev glue.
 411          */
 412
 413         status = usb_string_ids_tab(cdev, strings_dev);
 414         if (status < 0)
 415                 goto fail1;
 416         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 417         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 418
 419         /* register our configuration(s); RNDIS first, if it's used */
 420         if (has_rndis()) {
 421                 status = usb_add_config(cdev, &rndis_config_driver,
 422                                 rndis_do_config);
 423                 if (status < 0)
 424                         goto fail1;
 425         }
 426
 427         status = usb_add_config(cdev, &eth_config_driver, eth_do_config);
 428         if (status < 0)
 429                 goto fail1;
 430
 431         usb_composite_overwrite_options(cdev, &coverwrite);
 432         dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
 433                         DRIVER_DESC);
 434
 435         return 0;
 436
 437 fail1:
 438         if (has_rndis())
 439                 usb_put_function_instance(fi_rndis);
 440 fail:
 441         if (use_eem)
 442                 usb_put_function_instance(fi_eem);
 443         else if (can_support_ecm(gadget))
 444                 usb_put_function_instance(fi_ecm);
 445         else
 446                 usb_put_function_instance(fi_geth);
 447         return status;
 448 }
 449
 450 static int __exit eth_unbind(struct usb_composite_dev *cdev)
 451 {
 452         if (has_rndis())
 453                 usb_put_function_instance(fi_rndis);
 454         if (use_eem)
 455                 usb_put_function_instance(fi_eem);
 456         else if (can_support_ecm(cdev->gadget))
 457                 usb_put_function_instance(fi_ecm);
 458         else
 459                 usb_put_function_instance(fi_geth);
 460         return 0;
 461 }
 462
 463 static __refdata struct usb_composite_driver eth_driver = {
 464         .name           = "g_ether",
 465         .dev            = &device_desc,
 466         .strings        = dev_strings,
 467         .max_speed      = USB_SPEED_SUPER,
 468         .bind           = eth_bind,
 469         .unbind         = __exit_p(eth_unbind),
 470 };
 471
 472 MODULE_DESCRIPTION(PREFIX DRIVER_DESC);
 473 MODULE_AUTHOR("David Brownell, Benedikt Spanger");
 474 MODULE_LICENSE("GPL");
 475
 476 static int __init init(void)
 477 {
 478         return usb_composite_probe(&eth_driver);
 479 }
 480 module_init(init);
 481
 482 static void __exit cleanup(void)
 483 {
 484         usb_composite_unregister(&eth_driver);
 485 }
 486 module_exit(cleanup);