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 const struct usb_descriptor_header *otg_desc[2]; 175 176 static struct usb_string strings_dev[] = { 177 [USB_GADGET_MANUFACTURER_IDX].s = "", 178 [USB_GADGET_PRODUCT_IDX].s = PREFIX DRIVER_DESC, 179 [USB_GADGET_SERIAL_IDX].s = "", 180 { } /* end of list */ 181 }; 182 183 static struct usb_gadget_strings stringtab_dev = { 184 .language = 0x0409, /* en-us */ 185 .strings = strings_dev, 186 }; 187 188 static struct usb_gadget_strings *dev_strings[] = { 189 &stringtab_dev, 190 NULL, 191 }; 192 193 static struct usb_function_instance *fi_ecm; 194 static struct usb_function *f_ecm; 195 196 static struct usb_function_instance *fi_eem; 197 static struct usb_function *f_eem; 198 199 static struct usb_function_instance *fi_geth; 200 static struct usb_function *f_geth; 201 202 static struct usb_function_instance *fi_rndis; 203 static struct usb_function *f_rndis; 204 205 /*-------------------------------------------------------------------------*/ 206 207 /* 208 * We may not have an RNDIS configuration, but if we do it needs to be 209 * the first one present. That's to make Microsoft's drivers happy, 210 * and to follow DOCSIS 1.0 (cable modem standard). 211 */ 212 static int rndis_do_config(struct usb_configuration *c) 213 { 214 int status; 215 216 /* FIXME alloc iConfiguration string, set it in c->strings */ 217 218 if (gadget_is_otg(c->cdev->gadget)) { 219 c->descriptors = otg_desc; 220 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; 221 } 222 223 f_rndis = usb_get_function(fi_rndis); 224 if (IS_ERR(f_rndis)) 225 return PTR_ERR(f_rndis); 226 227 status = usb_add_function(c, f_rndis); 228 if (status < 0) 229 usb_put_function(f_rndis); 230 231 return status; 232 } 233 234 static struct usb_configuration rndis_config_driver = { 235 .label = "RNDIS", 236 .bConfigurationValue = 2, 237 /* .iConfiguration = DYNAMIC */ 238 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 239 }; 240 241 /*-------------------------------------------------------------------------*/ 242 243 #ifdef CONFIG_USB_ETH_EEM 244 static bool use_eem = 1; 245 #else 246 static bool use_eem; 247 #endif 248 module_param(use_eem, bool, 0); 249 MODULE_PARM_DESC(use_eem, "use CDC EEM mode"); 250 251 /* 252 * We _always_ have an ECM, CDC Subset, or EEM configuration. 253 */ 254 static int eth_do_config(struct usb_configuration *c) 255 { 256 int status = 0; 257 258 /* FIXME alloc iConfiguration string, set it in c->strings */ 259 260 if (gadget_is_otg(c->cdev->gadget)) { 261 c->descriptors = otg_desc; 262 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; 263 } 264 265 if (use_eem) { 266 f_eem = usb_get_function(fi_eem); 267 if (IS_ERR(f_eem)) 268 return PTR_ERR(f_eem); 269 270 status = usb_add_function(c, f_eem); 271 if (status < 0) 272 usb_put_function(f_eem); 273 274 return status; 275 } else if (can_support_ecm(c->cdev->gadget)) { 276 f_ecm = usb_get_function(fi_ecm); 277 if (IS_ERR(f_ecm)) 278 return PTR_ERR(f_ecm); 279 280 status = usb_add_function(c, f_ecm); 281 if (status < 0) 282 usb_put_function(f_ecm); 283 284 return status; 285 } else { 286 f_geth = usb_get_function(fi_geth); 287 if (IS_ERR(f_geth)) 288 return PTR_ERR(f_geth); 289 290 status = usb_add_function(c, f_geth); 291 if (status < 0) 292 usb_put_function(f_geth); 293 294 return status; 295 } 296 297 } 298 299 static struct usb_configuration eth_config_driver = { 300 /* .label = f(hardware) */ 301 .bConfigurationValue = 1, 302 /* .iConfiguration = DYNAMIC */ 303 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 304 }; 305 306 /*-------------------------------------------------------------------------*/ 307 308 static int eth_bind(struct usb_composite_dev *cdev) 309 { 310 struct usb_gadget *gadget = cdev->gadget; 311 struct f_eem_opts *eem_opts = NULL; 312 struct f_ecm_opts *ecm_opts = NULL; 313 struct f_gether_opts *geth_opts = NULL; 314 struct net_device *net; 315 int status; 316 317 /* set up main config label and device descriptor */ 318 if (use_eem) { 319 /* EEM */ 320 fi_eem = usb_get_function_instance("eem"); 321 if (IS_ERR(fi_eem)) 322 return PTR_ERR(fi_eem); 323 324 eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst); 325 326 net = eem_opts->net; 327 328 eth_config_driver.label = "CDC Ethernet (EEM)"; 329 device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM); 330 device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM); 331 } else if (can_support_ecm(gadget)) { 332 /* ECM */ 333 334 fi_ecm = usb_get_function_instance("ecm"); 335 if (IS_ERR(fi_ecm)) 336 return PTR_ERR(fi_ecm); 337 338 ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst); 339 340 net = ecm_opts->net; 341 342 eth_config_driver.label = "CDC Ethernet (ECM)"; 343 } else { 344 /* CDC Subset */ 345 346 fi_geth = usb_get_function_instance("geth"); 347 if (IS_ERR(fi_geth)) 348 return PTR_ERR(fi_geth); 349 350 geth_opts = container_of(fi_geth, struct f_gether_opts, 351 func_inst); 352 353 net = geth_opts->net; 354 355 eth_config_driver.label = "CDC Subset/SAFE"; 356 357 device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM); 358 device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM); 359 if (!has_rndis()) 360 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC; 361 } 362 363 gether_set_qmult(net, qmult); 364 if (!gether_set_host_addr(net, host_addr)) 365 pr_info("using host ethernet address: %s", host_addr); 366 if (!gether_set_dev_addr(net, dev_addr)) 367 pr_info("using self ethernet address: %s", dev_addr); 368 369 if (has_rndis()) { 370 /* RNDIS plus ECM-or-Subset */ 371 gether_set_gadget(net, cdev->gadget); 372 status = gether_register_netdev(net); 373 if (status) 374 goto fail; 375 376 if (use_eem) 377 eem_opts->bound = true; 378 else if (can_support_ecm(gadget)) 379 ecm_opts->bound = true; 380 else 381 geth_opts->bound = true; 382 383 fi_rndis = usb_get_function_instance("rndis"); 384 if (IS_ERR(fi_rndis)) { 385 status = PTR_ERR(fi_rndis); 386 goto fail; 387 } 388 389 rndis_borrow_net(fi_rndis, net); 390 391 device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM); 392 device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM); 393 device_desc.bNumConfigurations = 2; 394 } 395 396 /* Allocate string descriptor numbers ... note that string 397 * contents can be overridden by the composite_dev glue. 398 */ 399 400 status = usb_string_ids_tab(cdev, strings_dev); 401 if (status < 0) 402 goto fail1; 403 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 404 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 405 406 if (gadget_is_otg(gadget) && !otg_desc[0]) { 407 struct usb_descriptor_header *usb_desc; 408 409 usb_desc = usb_otg_descriptor_alloc(gadget); 410 if (!usb_desc) 411 goto fail1; 412 usb_otg_descriptor_init(gadget, usb_desc); 413 otg_desc[0] = usb_desc; 414 otg_desc[1] = NULL; 415 } 416 417 /* register our configuration(s); RNDIS first, if it's used */ 418 if (has_rndis()) { 419 status = usb_add_config(cdev, &rndis_config_driver, 420 rndis_do_config); 421 if (status < 0) 422 goto fail2; 423 } 424 425 status = usb_add_config(cdev, ð_config_driver, eth_do_config); 426 if (status < 0) 427 goto fail2; 428 429 usb_composite_overwrite_options(cdev, &coverwrite); 430 dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n", 431 DRIVER_DESC); 432 433 return 0; 434 435 fail2: 436 kfree(otg_desc[0]); 437 otg_desc[0] = NULL; 438 fail1: 439 if (has_rndis()) 440 usb_put_function_instance(fi_rndis); 441 fail: 442 if (use_eem) 443 usb_put_function_instance(fi_eem); 444 else if (can_support_ecm(gadget)) 445 usb_put_function_instance(fi_ecm); 446 else 447 usb_put_function_instance(fi_geth); 448 return status; 449 } 450 451 static int eth_unbind(struct usb_composite_dev *cdev) 452 { 453 if (has_rndis()) { 454 usb_put_function(f_rndis); 455 usb_put_function_instance(fi_rndis); 456 } 457 if (use_eem) { 458 usb_put_function(f_eem); 459 usb_put_function_instance(fi_eem); 460 } else if (can_support_ecm(cdev->gadget)) { 461 usb_put_function(f_ecm); 462 usb_put_function_instance(fi_ecm); 463 } else { 464 usb_put_function(f_geth); 465 usb_put_function_instance(fi_geth); 466 } 467 kfree(otg_desc[0]); 468 otg_desc[0] = NULL; 469 470 return 0; 471 } 472 473 static struct usb_composite_driver eth_driver = { 474 .name = "g_ether", 475 .dev = &device_desc, 476 .strings = dev_strings, 477 .max_speed = USB_SPEED_SUPER, 478 .bind = eth_bind, 479 .unbind = eth_unbind, 480 }; 481 482 module_usb_composite_driver(eth_driver); 483 484 MODULE_DESCRIPTION(PREFIX DRIVER_DESC); 485 MODULE_AUTHOR("David Brownell, Benedikt Spanger"); 486 MODULE_LICENSE("GPL"); 487