drivers/usb/gadget/ether.c - maze/linux - Git at Google

 /*
  * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
  *
  * Copyright (C) 2003-2005,2008 David Brownell
  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
  * Copyright (C) 2008 Nokia Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 /* #define VERBOSE_DEBUG */

 #include <linux/kernel.h>
 #include <linux/utsname.h>


 #if defined USB_ETH_RNDIS
 #  undef USB_ETH_RNDIS
 #endif
 #ifdef CONFIG_USB_ETH_RNDIS
 #  define USB_ETH_RNDIS y
 #endif

 #include "u_ether.h"


 /*
  * Ethernet gadget driver -- with CDC and non-CDC options
  * Builds on hardware support for a full duplex link.
  *
  * CDC Ethernet is the standard USB solution for sending Ethernet frames
  * using USB.  Real hardware tends to use the same framing protocol but look
  * different for control features.  This driver strongly prefers to use
  * this USB-IF standard as its open-systems interoperability solution;
  * most host side USB stacks (except from Microsoft) support it.
  *
  * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
  * TLA-soup.  "CDC ACM" (Abstract Control Model) is for modems, and a new
  * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
  *
  * There's some hardware that can't talk CDC ECM.  We make that hardware
  * implement a "minimalist" vendor-agnostic CDC core:  same framing, but
  * link-level setup only requires activating the configuration.  Only the
  * endpoint descriptors, and product/vendor IDs, are relevant; no control
  * operations are available.  Linux supports it, but other host operating
  * systems may not.  (This is a subset of CDC Ethernet.)
  *
  * It turns out that if you add a few descriptors to that "CDC Subset",
  * (Windows) host side drivers from MCCI can treat it as one submode of
  * a proprietary scheme called "SAFE" ... without needing to know about
  * specific product/vendor IDs.  So we do that, making it easier to use
  * those MS-Windows drivers.  Those added descriptors make it resemble a
  * CDC MDLM device, but they don't change device behavior at all.  (See
  * MCCI Engineering report 950198 "SAFE Networking Functions".)
  *
  * A third option is also in use.  Rather than CDC Ethernet, or something
  * simpler, Microsoft pushes their own approach: RNDIS.  The published
  * RNDIS specs are ambiguous and appear to be incomplete, and are also
  * needlessly complex.  They borrow more from CDC ACM than CDC ECM.
  */

 #define DRIVER_DESC		"Ethernet Gadget"
 #define DRIVER_VERSION		"Memorial Day 2008"

 #ifdef USB_ETH_RNDIS
 #define PREFIX			"RNDIS/"
 #else
 #define PREFIX			""
 #endif

 /*
  * This driver aims for interoperability by using CDC ECM unless
  *
  *		can_support_ecm()
  *
  * returns false, in which case it supports the CDC Subset.  By default,
  * that returns true; most hardware has no problems with CDC ECM, that's
  * a good default.  Previous versions of this driver had no default; this
  * version changes that, removing overhead for new controller support.
  *
  *	IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
  */

 static inline bool has_rndis(void)
 {
 #ifdef	USB_ETH_RNDIS
 	return true;
 #else
 	return false;
 #endif
 }

 /*-------------------------------------------------------------------------*/

 /*
  * Kbuild is not very cooperative with respect to linking separately
  * compiled library objects into one module.  So for now we won't use
  * separate compilation ... ensuring init/exit sections work to shrink
  * the runtime footprint, and giving us at least some parts of what
  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  */
 #include "composite.c"
 #include "usbstring.c"
 #include "config.c"
 #include "epautoconf.c"

 #include "f_ecm.c"
 #include "f_subset.c"
 #ifdef	USB_ETH_RNDIS
 #include "f_rndis.c"
 #include "rndis.c"
 #endif
 #include "f_eem.c"
 #include "u_ether.c"

 /*-------------------------------------------------------------------------*/

 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  * Instead:  allocate your own, using normal USB-IF procedures.
  */

 /* Thanks to NetChip Technologies for donating this product ID.
  * It's for devices with only CDC Ethernet configurations.
  */
 #define CDC_VENDOR_NUM		0x0525	/* NetChip */
 #define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */

 /* For hardware that can't talk CDC, we use the same vendor ID that
  * ARM Linux has used for ethernet-over-usb, both with sa1100 and
  * with pxa250.  We're protocol-compatible, if the host-side drivers
  * use the endpoint descriptors.  bcdDevice (version) is nonzero, so
  * drivers that need to hard-wire endpoint numbers have a hook.
  *
  * The protocol is a minimal subset of CDC Ether, which works on any bulk
  * hardware that's not deeply broken ... even on hardware that can't talk
  * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
  * doesn't handle control-OUT).
  */
 #define	SIMPLE_VENDOR_NUM	0x049f
 #define	SIMPLE_PRODUCT_NUM	0x505a

 /* For hardware that can talk RNDIS and either of the above protocols,
  * use this ID ... the windows INF files will know it.  Unless it's
  * used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
  * the non-RNDIS configuration.
  */
 #define RNDIS_VENDOR_NUM	0x0525	/* NetChip */
 #define RNDIS_PRODUCT_NUM	0xa4a2	/* Ethernet/RNDIS Gadget */

 /* For EEM gadgets */
 #define EEM_VENDOR_NUM		0x1d6b	/* Linux Foundation */
 #define EEM_PRODUCT_NUM		0x0102	/* EEM Gadget */

 /*-------------------------------------------------------------------------*/

 static struct usb_device_descriptor device_desc = {
 	.bLength =		sizeof device_desc,
 	.bDescriptorType =	USB_DT_DEVICE,

 	.bcdUSB =		cpu_to_le16 (0x0200),

 	.bDeviceClass =		USB_CLASS_COMM,
 	.bDeviceSubClass =	0,
 	.bDeviceProtocol =	0,
 	/* .bMaxPacketSize0 = f(hardware) */

 	/* Vendor and product id defaults change according to what configs
 	 * we support.  (As does bNumConfigurations.)  These values can
 	 * also be overridden by module parameters.
 	 */
 	.idVendor =		cpu_to_le16 (CDC_VENDOR_NUM),
 	.idProduct =		cpu_to_le16 (CDC_PRODUCT_NUM),
 	/* .bcdDevice = f(hardware) */
 	/* .iManufacturer = DYNAMIC */
 	/* .iProduct = DYNAMIC */
 	/* NO SERIAL NUMBER */
 	.bNumConfigurations =	1,
 };

 static struct usb_otg_descriptor otg_descriptor = {
 	.bLength =		sizeof otg_descriptor,
 	.bDescriptorType =	USB_DT_OTG,

 	/* REVISIT SRP-only hardware is possible, although
 	 * it would not be called "OTG" ...
 	 */
 	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
 };

 static const struct usb_descriptor_header *otg_desc[] = {
 	(struct usb_descriptor_header *) &otg_descriptor,
 	NULL,
 };


 /* string IDs are assigned dynamically */

 #define STRING_MANUFACTURER_IDX		0
 #define STRING_PRODUCT_IDX		1

 static char manufacturer[50];

 static struct usb_string strings_dev[] = {
 	[STRING_MANUFACTURER_IDX].s = manufacturer,
 	[STRING_PRODUCT_IDX].s = PREFIX DRIVER_DESC,
 	{  } /* end of list */
 };

 static struct usb_gadget_strings stringtab_dev = {
 	.language	= 0x0409,	/* en-us */
 	.strings	= strings_dev,
 };

 static struct usb_gadget_strings *dev_strings[] = {
 	&stringtab_dev,
 	NULL,
 };

 static u8 hostaddr[ETH_ALEN];

 /*-------------------------------------------------------------------------*/

 /*
  * We may not have an RNDIS configuration, but if we do it needs to be
  * the first one present.  That's to make Microsoft's drivers happy,
  * and to follow DOCSIS 1.0 (cable modem standard).
  */
 static int __init rndis_do_config(struct usb_configuration *c)
 {
 	/* FIXME alloc iConfiguration string, set it in c->strings */

 	if (gadget_is_otg(c->cdev->gadget)) {
 		c->descriptors = otg_desc;
 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}

 	return rndis_bind_config(c, hostaddr);
 }

 static struct usb_configuration rndis_config_driver = {
 	.label			= "RNDIS",
 	.bConfigurationValue	= 2,
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
 };

 /*-------------------------------------------------------------------------*/

 #ifdef CONFIG_USB_ETH_EEM
 static int use_eem = 1;
 #else
 static int use_eem;
 #endif
 module_param(use_eem, bool, 0);
 MODULE_PARM_DESC(use_eem, "use CDC EEM mode");

 /*
  * We _always_ have an ECM, CDC Subset, or EEM configuration.
  */
 static int __init eth_do_config(struct usb_configuration *c)
 {
 	/* FIXME alloc iConfiguration string, set it in c->strings */

 	if (gadget_is_otg(c->cdev->gadget)) {
 		c->descriptors = otg_desc;
 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}

 	if (use_eem)
 		return eem_bind_config(c);
 	else if (can_support_ecm(c->cdev->gadget))
 		return ecm_bind_config(c, hostaddr);
 	else
 		return geth_bind_config(c, hostaddr);
 }

 static struct usb_configuration eth_config_driver = {
 	/* .label = f(hardware) */
 	.bConfigurationValue	= 1,
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
 };

 /*-------------------------------------------------------------------------*/

 static int __init eth_bind(struct usb_composite_dev *cdev)
 {
 	int			gcnum;
 	struct usb_gadget	*gadget = cdev->gadget;
 	int			status;

 	/* set up network link layer */
 	status = gether_setup(cdev->gadget, hostaddr);
 	if (status < 0)
 		return status;

 	/* set up main config label and device descriptor */
 	if (use_eem) {
 		/* EEM */
 		eth_config_driver.label = "CDC Ethernet (EEM)";
 		device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM);
 		device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM);
 	} else if (can_support_ecm(cdev->gadget)) {
 		/* ECM */
 		eth_config_driver.label = "CDC Ethernet (ECM)";
 	} else {
 		/* CDC Subset */
 		eth_config_driver.label = "CDC Subset/SAFE";

 		device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM);
 		device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM);
 		if (!has_rndis())
 			device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 	}

 	if (has_rndis()) {
 		/* RNDIS plus ECM-or-Subset */
 		device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM);
 		device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM);
 		device_desc.bNumConfigurations = 2;
 	}

 	gcnum = usb_gadget_controller_number(gadget);
 	if (gcnum >= 0)
 		device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
 	else {
 		/* We assume that can_support_ecm() tells the truth;
 		 * but if the controller isn't recognized at all then
 		 * that assumption is a bit more likely to be wrong.
 		 */
 		dev_warn(&gadget->dev,
 				"controller '%s' not recognized; trying %s\n",
 				gadget->name,
 				eth_config_driver.label);
 		device_desc.bcdDevice =
 			cpu_to_le16(0x0300 | 0x0099);
 	}


 	/* Allocate string descriptor numbers ... note that string
 	 * contents can be overridden by the composite_dev glue.
 	 */

 	/* device descriptor strings: manufacturer, product */
 	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 		init_utsname()->sysname, init_utsname()->release,
 		gadget->name);
 	status = usb_string_id(cdev);
 	if (status < 0)
 		goto fail;
 	strings_dev[STRING_MANUFACTURER_IDX].id = status;
 	device_desc.iManufacturer = status;

 	status = usb_string_id(cdev);
 	if (status < 0)
 		goto fail;
 	strings_dev[STRING_PRODUCT_IDX].id = status;
 	device_desc.iProduct = status;

 	/* register our configuration(s); RNDIS first, if it's used */
 	if (has_rndis()) {
 		status = usb_add_config(cdev, &rndis_config_driver,
 				rndis_do_config);
 		if (status < 0)
 			goto fail;
 	}

 	status = usb_add_config(cdev, &eth_config_driver, eth_do_config);
 	if (status < 0)
 		goto fail;

 	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
 			DRIVER_DESC);

 	return 0;

 fail:
 	gether_cleanup();
 	return status;
 }

 static int __exit eth_unbind(struct usb_composite_dev *cdev)
 {
 	gether_cleanup();
 	return 0;
 }

 static struct usb_composite_driver eth_driver = {
 	.name		= "g_ether",
 	.dev		= &device_desc,
 	.strings	= dev_strings,
 	.max_speed	= USB_SPEED_SUPER,
 	.unbind		= __exit_p(eth_unbind),
 };

 MODULE_DESCRIPTION(PREFIX DRIVER_DESC);
 MODULE_AUTHOR("David Brownell, Benedikt Spanger");
 MODULE_LICENSE("GPL");

 static int __init init(void)
 {
 	return usb_composite_probe(&eth_driver, eth_bind);
 }
 module_init(init);

 static void __exit cleanup(void)
 {
 	usb_composite_unregister(&eth_driver);
 }
 module_exit(cleanup);
	/*
	* ether.c -- Ethernet gadget driver, with CDC and non-CDC options
	*
	* Copyright (C) 2003-2005,2008 David Brownell
	* Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
	* Copyright (C) 2008 Nokia Corporation
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	/* #define VERBOSE_DEBUG */

	#include <linux/kernel.h>
	#include <linux/utsname.h>


	#if defined USB_ETH_RNDIS
	# undef USB_ETH_RNDIS
	#endif
	#ifdef CONFIG_USB_ETH_RNDIS
	# define USB_ETH_RNDIS y
	#endif

	#include "u_ether.h"


	/*
	* Ethernet gadget driver -- with CDC and non-CDC options
	* Builds on hardware support for a full duplex link.
	*
	* CDC Ethernet is the standard USB solution for sending Ethernet frames
	* using USB. Real hardware tends to use the same framing protocol but look
	* different for control features. This driver strongly prefers to use
	* this USB-IF standard as its open-systems interoperability solution;
	* most host side USB stacks (except from Microsoft) support it.
	*
	* This is sometimes called "CDC ECM" (Ethernet Control Model) to support
	* TLA-soup. "CDC ACM" (Abstract Control Model) is for modems, and a new
	* "CDC EEM" (Ethernet Emulation Model) is starting to spread.
	*
	* There's some hardware that can't talk CDC ECM. We make that hardware
	* implement a "minimalist" vendor-agnostic CDC core: same framing, but
	* link-level setup only requires activating the configuration. Only the
	* endpoint descriptors, and product/vendor IDs, are relevant; no control
	* operations are available. Linux supports it, but other host operating
	* systems may not. (This is a subset of CDC Ethernet.)
	*
	* It turns out that if you add a few descriptors to that "CDC Subset",
	* (Windows) host side drivers from MCCI can treat it as one submode of
	* a proprietary scheme called "SAFE" ... without needing to know about
	* specific product/vendor IDs. So we do that, making it easier to use
	* those MS-Windows drivers. Those added descriptors make it resemble a
	* CDC MDLM device, but they don't change device behavior at all. (See
	* MCCI Engineering report 950198 "SAFE Networking Functions".)
	*
	* A third option is also in use. Rather than CDC Ethernet, or something
	* simpler, Microsoft pushes their own approach: RNDIS. The published
	* RNDIS specs are ambiguous and appear to be incomplete, and are also
	* needlessly complex. They borrow more from CDC ACM than CDC ECM.
	*/

	#define DRIVER_DESC "Ethernet Gadget"
	#define DRIVER_VERSION "Memorial Day 2008"

	#ifdef USB_ETH_RNDIS
	#define PREFIX "RNDIS/"
	#else
	#define PREFIX ""
	#endif

	/*
	* This driver aims for interoperability by using CDC ECM unless
	*
	* can_support_ecm()
	*
	* returns false, in which case it supports the CDC Subset. By default,
	* that returns true; most hardware has no problems with CDC ECM, that's
	* a good default. Previous versions of this driver had no default; this
	* version changes that, removing overhead for new controller support.
	*
	* IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
	*/

	static inline bool has_rndis(void)
	{
	#ifdef USB_ETH_RNDIS
	return true;
	#else
	return false;
	#endif
	}

	/-------------------------------------------------------------------------/

	/*
	* Kbuild is not very cooperative with respect to linking separately
	* compiled library objects into one module. So for now we won't use
	* separate compilation ... ensuring init/exit sections work to shrink
	* the runtime footprint, and giving us at least some parts of what
	* a "gcc --combine ... part1.c part2.c part3.c ... " build would.
	*/
	#include "composite.c"
	#include "usbstring.c"
	#include "config.c"
	#include "epautoconf.c"

	#include "f_ecm.c"
	#include "f_subset.c"
	#ifdef USB_ETH_RNDIS
	#include "f_rndis.c"
	#include "rndis.c"
	#endif
	#include "f_eem.c"
	#include "u_ether.c"

	/-------------------------------------------------------------------------/

	/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
	* Instead: allocate your own, using normal USB-IF procedures.
	*/

	/* Thanks to NetChip Technologies for donating this product ID.
	* It's for devices with only CDC Ethernet configurations.
	*/
	#define CDC_VENDOR_NUM 0x0525 /* NetChip */
	#define CDC_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */

	/* For hardware that can't talk CDC, we use the same vendor ID that
	* ARM Linux has used for ethernet-over-usb, both with sa1100 and
	* with pxa250. We're protocol-compatible, if the host-side drivers
	* use the endpoint descriptors. bcdDevice (version) is nonzero, so
	* drivers that need to hard-wire endpoint numbers have a hook.
	*
	* The protocol is a minimal subset of CDC Ether, which works on any bulk
	* hardware that's not deeply broken ... even on hardware that can't talk
	* RNDIS (like SA-1100, with no interrupt endpoint, or anything that
	* doesn't handle control-OUT).
	*/
	#define SIMPLE_VENDOR_NUM 0x049f
	#define SIMPLE_PRODUCT_NUM 0x505a

	/* For hardware that can talk RNDIS and either of the above protocols,
	* use this ID ... the windows INF files will know it. Unless it's
	* used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
	* the non-RNDIS configuration.
	*/
	#define RNDIS_VENDOR_NUM 0x0525 /* NetChip */
	#define RNDIS_PRODUCT_NUM 0xa4a2 /* Ethernet/RNDIS Gadget */

	/* For EEM gadgets */
	#define EEM_VENDOR_NUM 0x1d6b /* Linux Foundation */
	#define EEM_PRODUCT_NUM 0x0102 /* EEM Gadget */

	/-------------------------------------------------------------------------/

	static struct usb_device_descriptor device_desc = {
	.bLength = sizeof device_desc,
	.bDescriptorType = USB_DT_DEVICE,

	.bcdUSB = cpu_to_le16 (0x0200),

	.bDeviceClass = USB_CLASS_COMM,
	.bDeviceSubClass = 0,
	.bDeviceProtocol = 0,
	/* .bMaxPacketSize0 = f(hardware) */

	/* Vendor and product id defaults change according to what configs
	* we support. (As does bNumConfigurations.) These values can
	* also be overridden by module parameters.
	*/
	.idVendor = cpu_to_le16 (CDC_VENDOR_NUM),
	.idProduct = cpu_to_le16 (CDC_PRODUCT_NUM),
	/* .bcdDevice = f(hardware) */
	/* .iManufacturer = DYNAMIC */
	/* .iProduct = DYNAMIC */
	/* NO SERIAL NUMBER */
	.bNumConfigurations = 1,
	};

	static struct usb_otg_descriptor otg_descriptor = {
	.bLength = sizeof otg_descriptor,
	.bDescriptorType = USB_DT_OTG,

	/* REVISIT SRP-only hardware is possible, although
	* it would not be called "OTG" ...
	*/
	.bmAttributes = USB_OTG_SRP \| USB_OTG_HNP,
	};

	static const struct usb_descriptor_header *otg_desc[] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	NULL,
	};


	/* string IDs are assigned dynamically */

	#define STRING_MANUFACTURER_IDX 0
	#define STRING_PRODUCT_IDX 1

	static char manufacturer[50];

	static struct usb_string strings_dev[] = {
	[STRING_MANUFACTURER_IDX].s = manufacturer,
	[STRING_PRODUCT_IDX].s = PREFIX DRIVER_DESC,
	{ } /* end of list */
	};

	static struct usb_gadget_strings stringtab_dev = {
	.language = 0x0409, /* en-us */
	.strings = strings_dev,
	};

	static struct usb_gadget_strings *dev_strings[] = {
	&stringtab_dev,
	NULL,
	};

	static u8 hostaddr[ETH_ALEN];

	/-------------------------------------------------------------------------/

	/*
	* We may not have an RNDIS configuration, but if we do it needs to be
	* the first one present. That's to make Microsoft's drivers happy,
	* and to follow DOCSIS 1.0 (cable modem standard).
	*/
	static int __init rndis_do_config(struct usb_configuration *c)
	{
	/* FIXME alloc iConfiguration string, set it in c->strings */

	if (gadget_is_otg(c->cdev->gadget)) {
	c->descriptors = otg_desc;
	c->bmAttributes \|= USB_CONFIG_ATT_WAKEUP;
	}

	return rndis_bind_config(c, hostaddr);
	}

	static struct usb_configuration rndis_config_driver = {
	.label = "RNDIS",
	.bConfigurationValue = 2,
	/* .iConfiguration = DYNAMIC */
	.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
	};

	/-------------------------------------------------------------------------/

	#ifdef CONFIG_USB_ETH_EEM
	static int use_eem = 1;
	#else
	static int use_eem;
	#endif
	module_param(use_eem, bool, 0);
	MODULE_PARM_DESC(use_eem, "use CDC EEM mode");

	/*
	* We _always_ have an ECM, CDC Subset, or EEM configuration.
	*/
	static int __init eth_do_config(struct usb_configuration *c)
	{
	/* FIXME alloc iConfiguration string, set it in c->strings */

	if (gadget_is_otg(c->cdev->gadget)) {
	c->descriptors = otg_desc;
	c->bmAttributes \|= USB_CONFIG_ATT_WAKEUP;
	}

	if (use_eem)
	return eem_bind_config(c);
	else if (can_support_ecm(c->cdev->gadget))
	return ecm_bind_config(c, hostaddr);
	else
	return geth_bind_config(c, hostaddr);
	}

	static struct usb_configuration eth_config_driver = {
	/* .label = f(hardware) */
	.bConfigurationValue = 1,
	/* .iConfiguration = DYNAMIC */
	.bmAttributes = USB_CONFIG_ATT_SELFPOWER,
	};

	/-------------------------------------------------------------------------/

	static int __init eth_bind(struct usb_composite_dev *cdev)
	{
	int gcnum;
	struct usb_gadget *gadget = cdev->gadget;
	int status;

	/* set up network link layer */
	status = gether_setup(cdev->gadget, hostaddr);
	if (status < 0)
	return status;

	/* set up main config label and device descriptor */
	if (use_eem) {
	/* EEM */
	eth_config_driver.label = "CDC Ethernet (EEM)";
	device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM);
	device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM);
	} else if (can_support_ecm(cdev->gadget)) {
	/* ECM */
	eth_config_driver.label = "CDC Ethernet (ECM)";
	} else {
	/* CDC Subset */
	eth_config_driver.label = "CDC Subset/SAFE";

	device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM);
	device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM);
	if (!has_rndis())
	device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
	}

	if (has_rndis()) {
	/* RNDIS plus ECM-or-Subset */
	device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM);
	device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM);
	device_desc.bNumConfigurations = 2;
	}

	gcnum = usb_gadget_controller_number(gadget);
	if (gcnum >= 0)
	device_desc.bcdDevice = cpu_to_le16(0x0300 \| gcnum);
	else {
	/* We assume that can_support_ecm() tells the truth;
	* but if the controller isn't recognized at all then
	* that assumption is a bit more likely to be wrong.
	*/
	dev_warn(&gadget->dev,
	"controller '%s' not recognized; trying %s\n",
	gadget->name,
	eth_config_driver.label);
	device_desc.bcdDevice =
	cpu_to_le16(0x0300 \| 0x0099);
	}


	/* Allocate string descriptor numbers ... note that string
	* contents can be overridden by the composite_dev glue.
	*/

	/* device descriptor strings: manufacturer, product */
	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
	init_utsname()->sysname, init_utsname()->release,
	gadget->name);
	status = usb_string_id(cdev);
	if (status < 0)
	goto fail;
	strings_dev[STRING_MANUFACTURER_IDX].id = status;
	device_desc.iManufacturer = status;

	status = usb_string_id(cdev);
	if (status < 0)
	goto fail;
	strings_dev[STRING_PRODUCT_IDX].id = status;
	device_desc.iProduct = status;

	/* register our configuration(s); RNDIS first, if it's used */
	if (has_rndis()) {
	status = usb_add_config(cdev, &rndis_config_driver,
	rndis_do_config);
	if (status < 0)
	goto fail;
	}

	status = usb_add_config(cdev, &eth_config_driver, eth_do_config);
	if (status < 0)
	goto fail;

	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
	DRIVER_DESC);

	return 0;

	fail:
	gether_cleanup();
	return status;
	}

	static int __exit eth_unbind(struct usb_composite_dev *cdev)
	{
	gether_cleanup();
	return 0;
	}

	static struct usb_composite_driver eth_driver = {
	.name = "g_ether",
	.dev = &device_desc,
	.strings = dev_strings,
	.max_speed = USB_SPEED_SUPER,
	.unbind = __exit_p(eth_unbind),
	};

	MODULE_DESCRIPTION(PREFIX DRIVER_DESC);
	MODULE_AUTHOR("David Brownell, Benedikt Spanger");
	MODULE_LICENSE("GPL");

	static int __init init(void)
	{
	return usb_composite_probe(&eth_driver, eth_bind);
	}
	module_init(init);

	static void __exit cleanup(void)
	{
	usb_composite_unregister(&eth_driver);
	}
	module_exit(cleanup);