usb ethernet gadget: split CDC Ethernet function (da741b8c) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/usb/gadget/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -25,7 +25,7 @@ obj-$(CONFIG_USB_M66592) += m66592-udc.o
		C_UTILS = composite.o usbstring.o config.o epautoconf.o

		g_zero-objs := zero.o f_sourcesink.o f_loopback.o $(C_UTILS)
		g_ether-objs := ether.o u_ether.o f_subset.o $(C_UTILS)
		g_ether-objs := ether.o u_ether.o f_subset.o f_ecm.o $(C_UTILS)
		g_serial-objs := serial.o u_serial.o f_acm.o f_serial.o $(C_UTILS)
		g_midi-objs := gmidi.o usbstring.o config.o epautoconf.o
		gadgetfs-objs := inode.o

drivers/usb/gadget/f_ecm.c

0 → 100644

+833 −0

Original line number	Diff line number	Diff line
		/*
		* f_ecm.c -- USB CDC Ethernet (ECM) link function driver
		*
		* Copyright (C) 2003-2005,2008 David Brownell
		* 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/device.h>
		#include <linux/etherdevice.h>

		#include "u_ether.h"


		/*
		* This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
		* Ethernet link. The data transfer model is simple (packets sent and
		* received over bulk endpoints using normal short packet termination),
		* and the control model exposes various data and optional notifications.
		*
		* ECM is well standardized and (except for Microsoft) supported by most
		* operating systems with USB host support. It's the preferred interop
		* solution for Ethernet over USB, at least for firmware based solutions.
		* (Hardware solutions tend to be more minimalist.) A newer and simpler
		* "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
		*
		* Note that ECM requires the use of "alternate settings" for its data
		* interface. This means that the set_alt() method has real work to do,
		* and also means that a get_alt() method is required.
		*/

		struct ecm_ep_descs {
		struct usb_endpoint_descriptor *in;
		struct usb_endpoint_descriptor *out;
		struct usb_endpoint_descriptor *notify;
		};

		enum ecm_notify_state {
		ECM_NOTIFY_NONE, /* don't notify */
		ECM_NOTIFY_CONNECT, /* issue CONNECT next */
		ECM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */
		};

		struct f_ecm {
		struct gether port;
		u8 ctrl_id, data_id;

		char ethaddr[14];

		struct usb_descriptor_header **fs_function;
		struct ecm_ep_descs fs;
		struct usb_descriptor_header **hs_function;
		struct ecm_ep_descs hs;

		struct usb_ep *notify;
		struct usb_endpoint_descriptor *notify_desc;
		struct usb_request *notify_req;
		u8 notify_state;
		bool is_open;

		/* FIXME is_open needs some irq-ish locking
		* ... possibly the same as port.ioport
		*/
		};

		static inline struct f_ecm func_to_ecm(struct usb_function f)
		{
		return container_of(f, struct f_ecm, port.func);
		}

		/* peak (theoretical) bulk transfer rate in bits-per-second */
		static inline unsigned bitrate(struct usb_gadget *g)
		{
		if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
		return 13 * 512 * 8 * 1000 * 8;
		else
		return 19 * 64 * 1 * 1000 * 8;
		}

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

		/*
		* Include the status endpoint if we can, even though it's optional.
		*
		* Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
		* packet, to simplify cancellation; and a big transfer interval, to
		* waste less bandwidth.
		*
		* Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
		* if they ignore the connect/disconnect notifications that real aether
		* can provide. More advanced cdc configurations might want to support
		* encapsulated commands (vendor-specific, using control-OUT).
		*/

		#define LOG2_STATUS_INTERVAL_MSEC 5 /* 1 << 5 == 32 msec */
		#define STATUS_BYTECOUNT 16 /* 8 byte header + data */


		/* interface descriptor: */

		static struct usb_interface_descriptor ecm_control_intf __initdata = {
		.bLength = sizeof ecm_control_intf,
		.bDescriptorType = USB_DT_INTERFACE,

		/* .bInterfaceNumber = DYNAMIC */
		/* status endpoint is optional; this could be patched later */
		.bNumEndpoints = 1,
		.bInterfaceClass = USB_CLASS_COMM,
		.bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
		.bInterfaceProtocol = USB_CDC_PROTO_NONE,
		/* .iInterface = DYNAMIC */
		};

		static struct usb_cdc_header_desc header_desc __initdata = {
		.bLength = sizeof header_desc,
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_HEADER_TYPE,

		.bcdCDC = __constant_cpu_to_le16(0x0110),
		};

		static struct usb_cdc_union_desc ecm_union_desc __initdata = {
		.bLength = sizeof(ecm_union_desc),
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_UNION_TYPE,
		/* .bMasterInterface0 = DYNAMIC */
		/* .bSlaveInterface0 = DYNAMIC */
		};

		static struct usb_cdc_ether_desc ether_desc __initdata = {
		.bLength = sizeof ether_desc,
		.bDescriptorType = USB_DT_CS_INTERFACE,
		.bDescriptorSubType = USB_CDC_ETHERNET_TYPE,

		/* this descriptor actually adds value, surprise! */
		/* .iMACAddress = DYNAMIC */
		.bmEthernetStatistics = __constant_cpu_to_le32(0), /* no statistics */
		.wMaxSegmentSize = __constant_cpu_to_le16(ETH_FRAME_LEN),
		.wNumberMCFilters = __constant_cpu_to_le16(0),
		.bNumberPowerFilters = 0,
		};

		/* the default data interface has no endpoints ... */

		static struct usb_interface_descriptor ecm_data_nop_intf __initdata = {
		.bLength = sizeof ecm_data_nop_intf,
		.bDescriptorType = USB_DT_INTERFACE,

		.bInterfaceNumber = 1,
		.bAlternateSetting = 0,
		.bNumEndpoints = 0,
		.bInterfaceClass = USB_CLASS_CDC_DATA,
		.bInterfaceSubClass = 0,
		.bInterfaceProtocol = 0,
		/* .iInterface = DYNAMIC */
		};

		/* ... but the "real" data interface has two bulk endpoints */

		static struct usb_interface_descriptor ecm_data_intf __initdata = {
		.bLength = sizeof ecm_data_intf,
		.bDescriptorType = USB_DT_INTERFACE,

		.bInterfaceNumber = 1,
		.bAlternateSetting = 1,
		.bNumEndpoints = 2,
		.bInterfaceClass = USB_CLASS_CDC_DATA,
		.bInterfaceSubClass = 0,
		.bInterfaceProtocol = 0,
		/* .iInterface = DYNAMIC */
		};

		/* full speed support: */

		static struct usb_endpoint_descriptor fs_notify_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_INT,
		.wMaxPacketSize = __constant_cpu_to_le16(STATUS_BYTECOUNT),
		.bInterval = 1 << LOG2_STATUS_INTERVAL_MSEC,
		};

		static struct usb_endpoint_descriptor fs_in_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_BULK,
		};

		static struct usb_endpoint_descriptor fs_out_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_OUT,
		.bmAttributes = USB_ENDPOINT_XFER_BULK,
		};

		static struct usb_descriptor_header *eth_fs_function[] __initdata = {
		/* CDC ECM control descriptors */
		(struct usb_descriptor_header *) &ecm_control_intf,
		(struct usb_descriptor_header *) &header_desc,
		(struct usb_descriptor_header *) &ecm_union_desc,
		(struct usb_descriptor_header *) &ether_desc,
		/* NOTE: status endpoint might need to be removed */
		(struct usb_descriptor_header *) &fs_notify_desc,
		/* data interface, altsettings 0 and 1 */
		(struct usb_descriptor_header *) &ecm_data_nop_intf,
		(struct usb_descriptor_header *) &ecm_data_intf,
		(struct usb_descriptor_header *) &fs_in_desc,
		(struct usb_descriptor_header *) &fs_out_desc,
		NULL,
		};

		/* high speed support: */

		static struct usb_endpoint_descriptor hs_notify_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_INT,
		.wMaxPacketSize = __constant_cpu_to_le16(STATUS_BYTECOUNT),
		.bInterval = LOG2_STATUS_INTERVAL_MSEC + 4,
		};
		static struct usb_endpoint_descriptor hs_in_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_IN,
		.bmAttributes = USB_ENDPOINT_XFER_BULK,
		.wMaxPacketSize = __constant_cpu_to_le16(512),
		};

		static struct usb_endpoint_descriptor hs_out_desc __initdata = {
		.bLength = USB_DT_ENDPOINT_SIZE,
		.bDescriptorType = USB_DT_ENDPOINT,

		.bEndpointAddress = USB_DIR_OUT,
		.bmAttributes = USB_ENDPOINT_XFER_BULK,
		.wMaxPacketSize = __constant_cpu_to_le16(512),
		};

		static struct usb_descriptor_header *eth_hs_function[] __initdata = {
		/* CDC ECM control descriptors */
		(struct usb_descriptor_header *) &ecm_control_intf,
		(struct usb_descriptor_header *) &header_desc,
		(struct usb_descriptor_header *) &ecm_union_desc,
		(struct usb_descriptor_header *) &ether_desc,
		/* NOTE: status endpoint might need to be removed */
		(struct usb_descriptor_header *) &hs_notify_desc,
		/* data interface, altsettings 0 and 1 */
		(struct usb_descriptor_header *) &ecm_data_nop_intf,
		(struct usb_descriptor_header *) &ecm_data_intf,
		(struct usb_descriptor_header *) &hs_in_desc,
		(struct usb_descriptor_header *) &hs_out_desc,
		NULL,
		};

		/* string descriptors: */

		static struct usb_string ecm_string_defs[] = {
		[0].s = "CDC Ethernet Control Model (ECM)",
		[1].s = NULL /* DYNAMIC */,
		[2].s = "CDC Ethernet Data",
		{ } /* end of list */
		};

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

		static struct usb_gadget_strings *ecm_strings[] = {
		&ecm_string_table,
		NULL,
		};

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

		static void ecm_do_notify(struct f_ecm *ecm)
		{
		struct usb_request *req = ecm->notify_req;
		struct usb_cdc_notification *event;
		struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
		__le32 *data;
		int status;

		/* notification already in flight? */
		if (!req)
		return;

		event = req->buf;
		switch (ecm->notify_state) {
		case ECM_NOTIFY_NONE:
		return;

		case ECM_NOTIFY_CONNECT:
		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
		if (ecm->is_open)
		event->wValue = cpu_to_le16(1);
		else
		event->wValue = cpu_to_le16(0);
		event->wLength = 0;
		req->length = sizeof *event;

		DBG(cdev, "notify connect %s\n",
		ecm->is_open ? "true" : "false");
		ecm->notify_state = ECM_NOTIFY_SPEED;
		break;

		case ECM_NOTIFY_SPEED:
		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
		event->wValue = cpu_to_le16(0);
		event->wLength = cpu_to_le16(8);
		req->length = STATUS_BYTECOUNT;

		/* SPEED_CHANGE data is up/down speeds in bits/sec */
		data = req->buf + sizeof *event;
		data[0] = cpu_to_le32(bitrate(cdev->gadget));
		data[1] = data[0];

		DBG(cdev, "notify speed %d\n", bitrate(cdev->gadget));
		ecm->notify_state = ECM_NOTIFY_NONE;
		break;
		}
		event->bmRequestType = 0xA1;
		event->wIndex = cpu_to_le16(ecm->ctrl_id);

		ecm->notify_req = NULL;
		status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
		if (status < 0) {
		ecm->notify_req = req;
		DBG(cdev, "notify --> %d\n", status);
		}
		}

		static void ecm_notify(struct f_ecm *ecm)
		{
		/* NOTE on most versions of Linux, host side cdc-ethernet
		* won't listen for notifications until its netdevice opens.
		* The first notification then sits in the FIFO for a long
		* time, and the second one is queued.
		*/
		ecm->notify_state = ECM_NOTIFY_CONNECT;
		ecm_do_notify(ecm);
		}

		static void ecm_notify_complete(struct usb_ep ep, struct usb_request req)
		{
		struct f_ecm *ecm = req->context;
		struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
		struct usb_cdc_notification *event = req->buf;

		switch (req->status) {
		case 0:
		/* no fault */
		break;
		case -ECONNRESET:
		case -ESHUTDOWN:
		ecm->notify_state = ECM_NOTIFY_NONE;
		break;
		default:
		DBG(cdev, "event %02x --> %d\n",
		event->bNotificationType, req->status);
		break;
		}
		ecm->notify_req = req;
		ecm_do_notify(ecm);
		}

		static int ecm_setup(struct usb_function f, const struct usb_ctrlrequest ctrl)
		{
		struct f_ecm *ecm = func_to_ecm(f);
		struct usb_composite_dev *cdev = f->config->cdev;
		struct usb_request *req = cdev->req;
		int value = -EOPNOTSUPP;
		u16 w_index = le16_to_cpu(ctrl->wIndex);
		u16 w_value = le16_to_cpu(ctrl->wValue);
		u16 w_length = le16_to_cpu(ctrl->wLength);

		/* composite driver infrastructure handles everything except
		* CDC class messages; interface activation uses set_alt().
		*/
		switch ((ctrl->bRequestType << 8) \| ctrl->bRequest) {
		case ((USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE) << 8)
		\| USB_CDC_SET_ETHERNET_PACKET_FILTER:
		/* see 6.2.30: no data, wIndex = interface,
		* wValue = packet filter bitmap
		*/
		if (w_length != 0 \|\| w_index != ecm->ctrl_id)
		goto invalid;
		DBG(cdev, "packet filter %02x\n", w_value);
		/* REVISIT locking of cdc_filter. This assumes the UDC
		* driver won't have a concurrent packet TX irq running on
		* another CPU; or that if it does, this write is atomic...
		*/
		ecm->port.cdc_filter = w_value;
		value = 0;
		break;

		/* and optionally:
		* case USB_CDC_SEND_ENCAPSULATED_COMMAND:
		* case USB_CDC_GET_ENCAPSULATED_RESPONSE:
		* case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
		* case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
		* case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
		* case USB_CDC_GET_ETHERNET_STATISTIC:
		*/

		default:
		invalid:
		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
		ctrl->bRequestType, ctrl->bRequest,
		w_value, w_index, w_length);
		}

		/* respond with data transfer or status phase? */
		if (value >= 0) {
		DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
		ctrl->bRequestType, ctrl->bRequest,
		w_value, w_index, w_length);
		req->zero = 0;
		req->length = value;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0)
		ERROR(cdev, "ecm req %02x.%02x response err %d\n",
		ctrl->bRequestType, ctrl->bRequest,
		value);
		}

		/* device either stalls (value < 0) or reports success */
		return value;
		}


		static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
		{
		struct f_ecm *ecm = func_to_ecm(f);
		struct usb_composite_dev *cdev = f->config->cdev;

		/* Control interface has only altsetting 0 */
		if (intf == ecm->ctrl_id) {
		if (alt != 0)
		goto fail;

		if (ecm->notify->driver_data) {
		VDBG(cdev, "reset ecm control %d\n", intf);
		usb_ep_disable(ecm->notify);
		} else {
		VDBG(cdev, "init ecm ctrl %d\n", intf);
		ecm->notify_desc = ep_choose(cdev->gadget,
		ecm->hs.notify,
		ecm->fs.notify);
		}
		usb_ep_enable(ecm->notify, ecm->notify_desc);
		ecm->notify->driver_data = ecm;

		/* Data interface has two altsettings, 0 and 1 */
		} else if (intf == ecm->data_id) {
		if (alt > 1)
		goto fail;

		if (ecm->port.in_ep->driver_data) {
		DBG(cdev, "reset ecm\n");
		gether_disconnect(&ecm->port);
		}

		if (!ecm->port.in) {
		DBG(cdev, "init ecm\n");
		ecm->port.in = ep_choose(cdev->gadget,
		ecm->hs.in, ecm->fs.in);
		ecm->port.out = ep_choose(cdev->gadget,
		ecm->hs.out, ecm->fs.out);
		}

		/* CDC Ethernet only sends data in non-default altsettings.
		* Changing altsettings resets filters, statistics, etc.
		*/
		if (alt == 1) {
		struct net_device *net;

		/* Enable zlps by default for ECM conformance;
		* override for musb_hdrc (avoids txdma ovhead)
		* and sa1100 (can't).
		*/
		ecm->port.is_zlp_ok = !(
		gadget_is_sa1100(cdev->gadget)
		\|\| gadget_is_musbhdrc(cdev->gadget)
		);
		ecm->port.cdc_filter = DEFAULT_FILTER;
		DBG(cdev, "activate ecm\n");
		net = gether_connect(&ecm->port);
		if (IS_ERR(net))
		return PTR_ERR(net);
		}

		/* NOTE this can be a minor disagreement with the ECM spec,
		* which says speed notifications will "always" follow
		* connection notifications. But we allow one connect to
		* follow another (if the first is in flight), and instead
		* just guarantee that a speed notification is always sent.
		*/
		ecm_notify(ecm);
		} else
		goto fail;

		return 0;
		fail:
		return -EINVAL;
		}

		/* Because the data interface supports multiple altsettings,
		* this ECM function MUST implement a get_alt() method.
		*/
		static int ecm_get_alt(struct usb_function *f, unsigned intf)
		{
		struct f_ecm *ecm = func_to_ecm(f);

		if (intf == ecm->ctrl_id)
		return 0;
		return ecm->port.in_ep->driver_data ? 1 : 0;
		}

		static void ecm_disable(struct usb_function *f)
		{
		struct f_ecm *ecm = func_to_ecm(f);
		struct usb_composite_dev *cdev = f->config->cdev;

		DBG(cdev, "ecm deactivated\n");

		if (ecm->port.in_ep->driver_data)
		gether_disconnect(&ecm->port);

		if (ecm->notify->driver_data) {
		usb_ep_disable(ecm->notify);
		ecm->notify->driver_data = NULL;
		ecm->notify_desc = NULL;
		}
		}

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

		/*
		* Callbacks let us notify the host about connect/disconnect when the
		* net device is opened or closed.
		*
		* For testing, note that link states on this side include both opened
		* and closed variants of:
		*
		* - disconnected/unconfigured
		* - configured but inactive (data alt 0)
		* - configured and active (data alt 1)
		*
		* Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
		* SET_INTERFACE (altsetting). Remember also that "configured" doesn't
		* imply the host is actually polling the notification endpoint, and
		* likewise that "active" doesn't imply it's actually using the data
		* endpoints for traffic.
		*/

		static void ecm_open(struct gether *geth)
		{
		struct f_ecm *ecm = func_to_ecm(&geth->func);

		DBG(ecm->port.func.config->cdev, "%s\n", __func__);

		ecm->is_open = true;
		ecm_notify(ecm);
		}

		static void ecm_close(struct gether *geth)
		{
		struct f_ecm *ecm = func_to_ecm(&geth->func);

		DBG(ecm->port.func.config->cdev, "%s\n", __func__);

		ecm->is_open = false;
		ecm_notify(ecm);
		}

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

		/* ethernet function driver setup/binding */

		static int __init
		ecm_bind(struct usb_configuration c, struct usb_function f)
		{
		struct usb_composite_dev *cdev = c->cdev;
		struct f_ecm *ecm = func_to_ecm(f);
		int status;
		struct usb_ep *ep;

		/* allocate instance-specific interface IDs */
		status = usb_interface_id(c, f);
		if (status < 0)
		goto fail;
		ecm->ctrl_id = status;

		ecm_control_intf.bInterfaceNumber = status;
		ecm_union_desc.bMasterInterface0 = status;

		status = usb_interface_id(c, f);
		if (status < 0)
		goto fail;
		ecm->data_id = status;

		ecm_data_nop_intf.bInterfaceNumber = status;
		ecm_data_intf.bInterfaceNumber = status;
		ecm_union_desc.bSlaveInterface0 = status;

		status = -ENODEV;

		/* allocate instance-specific endpoints */
		ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
		if (!ep)
		goto fail;
		ecm->port.in_ep = ep;
		ep->driver_data = cdev; /* claim */

		ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
		if (!ep)
		goto fail;
		ecm->port.out_ep = ep;
		ep->driver_data = cdev; /* claim */

		/* NOTE: a status/notification endpoint is OPTIONAL but we
		* don't treat it that way. It's simpler, and some newer CDC
		* profiles (wireless handsets) no longer treat it as optional.
		*/
		ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
		if (!ep)
		goto fail;
		ecm->notify = ep;
		ep->driver_data = cdev; /* claim */

		status = -ENOMEM;

		/* allocate notification request and buffer */
		ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
		if (!ecm->notify_req)
		goto fail;
		ecm->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
		if (!ecm->notify_req->buf)
		goto fail;
		ecm->notify_req->context = ecm;
		ecm->notify_req->complete = ecm_notify_complete;

		/* copy descriptors, and track endpoint copies */
		f->descriptors = usb_copy_descriptors(eth_fs_function);
		if (!f->descriptors)
		goto fail;

		ecm->fs.in = usb_find_endpoint(eth_fs_function,
		f->descriptors, &fs_in_desc);
		ecm->fs.out = usb_find_endpoint(eth_fs_function,
		f->descriptors, &fs_out_desc);
		ecm->fs.notify = usb_find_endpoint(eth_fs_function,
		f->descriptors, &fs_notify_desc);

		/* support all relevant hardware speeds... we expect that when
		* hardware is dual speed, all bulk-capable endpoints work at
		* both speeds
		*/
		if (gadget_is_dualspeed(c->cdev->gadget)) {
		hs_in_desc.bEndpointAddress =
		fs_in_desc.bEndpointAddress;
		hs_out_desc.bEndpointAddress =
		fs_out_desc.bEndpointAddress;
		hs_notify_desc.bEndpointAddress =
		fs_notify_desc.bEndpointAddress;

		/* copy descriptors, and track endpoint copies */
		f->hs_descriptors = usb_copy_descriptors(eth_hs_function);
		if (!f->hs_descriptors)
		goto fail;

		ecm->hs.in = usb_find_endpoint(eth_hs_function,
		f->hs_descriptors, &hs_in_desc);
		ecm->hs.out = usb_find_endpoint(eth_hs_function,
		f->hs_descriptors, &hs_out_desc);
		ecm->hs.notify = usb_find_endpoint(eth_hs_function,
		f->hs_descriptors, &hs_notify_desc);
		}

		/* NOTE: all that is done without knowing or caring about
		* the network link ... which is unavailable to this code
		* until we're activated via set_alt().
		*/

		ecm->port.open = ecm_open;
		ecm->port.close = ecm_close;

		DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
		gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
		ecm->port.in_ep->name, ecm->port.out_ep->name,
		ecm->notify->name);
		return 0;

		fail:
		if (f->descriptors)
		usb_free_descriptors(f->descriptors);

		if (ecm->notify_req) {
		kfree(ecm->notify_req->buf);
		usb_ep_free_request(ecm->notify, ecm->notify_req);
		}

		/* we might as well release our claims on endpoints */
		if (ecm->notify)
		ecm->notify->driver_data = NULL;
		if (ecm->port.out)
		ecm->port.out_ep->driver_data = NULL;
		if (ecm->port.in)
		ecm->port.in_ep->driver_data = NULL;

		ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);

		return status;
		}

		static void
		ecm_unbind(struct usb_configuration c, struct usb_function f)
		{
		struct f_ecm *ecm = func_to_ecm(f);

		DBG(c->cdev, "ecm unbind\n");

		if (gadget_is_dualspeed(c->cdev->gadget))
		usb_free_descriptors(f->hs_descriptors);
		usb_free_descriptors(f->descriptors);

		kfree(ecm->notify_req->buf);
		usb_ep_free_request(ecm->notify, ecm->notify_req);

		ecm_string_defs[1].s = NULL;
		kfree(ecm);
		}

		/**
		* ecm_bind_config - add CDC Ethernet network link to a configuration
		* @c: the configuration to support the network link
		* @ethaddr: a buffer in which the ethernet address of the host side
		* side of the link was recorded
		* Context: single threaded during gadget setup
		*
		* Returns zero on success, else negative errno.
		*
		* Caller must have called @gether_setup(). Caller is also responsible
		* for calling @gether_cleanup() before module unload.
		*/
		int __init ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
		{
		struct f_ecm *ecm;
		int status;

		if (!can_support_ecm(c->cdev->gadget) \|\| !ethaddr)
		return -EINVAL;

		/* maybe allocate device-global string IDs */
		if (ecm_string_defs[0].id == 0) {

		/* control interface label */
		status = usb_string_id(c->cdev);
		if (status < 0)
		return status;
		ecm_string_defs[0].id = status;
		ecm_control_intf.iInterface = status;

		/* data interface label */
		status = usb_string_id(c->cdev);
		if (status < 0)
		return status;
		ecm_string_defs[2].id = status;
		ecm_data_intf.iInterface = status;

		/* MAC address */
		status = usb_string_id(c->cdev);
		if (status < 0)
		return status;
		ecm_string_defs[1].id = status;
		ether_desc.iMACAddress = status;
		}

		/* allocate and initialize one new instance */
		ecm = kzalloc(sizeof *ecm, GFP_KERNEL);
		if (!ecm)
		return -ENOMEM;

		/* export host's Ethernet address in CDC format */
		snprintf(ecm->ethaddr, sizeof ecm->ethaddr,
		"%02X%02X%02X%02X%02X%02X",
		ethaddr[0], ethaddr[1], ethaddr[2],
		ethaddr[3], ethaddr[4], ethaddr[5]);
		ecm_string_defs[1].s = ecm->ethaddr;

		ecm->port.cdc_filter = DEFAULT_FILTER;

		ecm->port.func.name = "cdc_ethernet";
		ecm->port.func.strings = ecm_strings;
		/* descriptors are per-instance copies */
		ecm->port.func.bind = ecm_bind;
		ecm->port.func.unbind = ecm_unbind;
		ecm->port.func.set_alt = ecm_set_alt;
		ecm->port.func.get_alt = ecm_get_alt;
		ecm->port.func.setup = ecm_setup;
		ecm->port.func.disable = ecm_disable;

		status = usb_add_function(c, &ecm->port.func);
		if (status) {
		ecm_string_defs[1].s = NULL;
		kfree(ecm);
		}
		return status;
		}