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, ð_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(f_rndis); 454 usb_put_function_instance(fi_rndis); 455 } 456 if (use_eem) { 457 usb_put_function(f_eem); 458 usb_put_function_instance(fi_eem); 459 } else if (can_support_ecm(cdev->gadget)) { 460 usb_put_function(f_ecm); 461 usb_put_function_instance(fi_ecm); 462 } else { 463 usb_put_function(f_geth); 464 usb_put_function_instance(fi_geth); 465 } 466 return 0; 467 } 468 469 static __refdata struct usb_composite_driver eth_driver = { 470 .name = "g_ether", 471 .dev = &device_desc, 472 .strings = dev_strings, 473 .max_speed = USB_SPEED_SUPER, 474 .bind = eth_bind, 475 .unbind = __exit_p(eth_unbind), 476 }; 477 478 module_usb_composite_driver(eth_driver); 479 480 MODULE_DESCRIPTION(PREFIX DRIVER_DESC); 481 MODULE_AUTHOR("David Brownell, Benedikt Spanger"); 482 MODULE_LICENSE("GPL"); 483