composite.h 25 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641
/*
 * composite.h -- framework for usb gadgets which are composite devices
 *
 * Copyright (C) 2006-2008 David Brownell
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef	__LINUX_USB_COMPOSITE_H
#define	__LINUX_USB_COMPOSITE_H

/*
 * This framework is an optional layer on top of the USB Gadget interface,
 * making it easier to build (a) Composite devices, supporting multiple
 * functions within any single configuration, and (b) Multi-configuration
 * devices, also supporting multiple functions but without necessarily
 * having more than one function per configuration.
 *
 * Example:  a device with a single configuration supporting both network
 * link and mass storage functions is a composite device.  Those functions
 * might alternatively be packaged in individual configurations, but in
 * the composite model the host can use both functions at the same time.
 */

#include <linux/bcd.h>
#include <linux/version.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/log2.h>
#include <linux/configfs.h>

/*
 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
 * wish to delay the data/status stages of the control transfer till they
 * are ready. The control transfer will then be kept from completing till
 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
 * invoke usb_composite_setup_continue().
 */
#define USB_GADGET_DELAYED_STATUS       0x7fff	/* Impossibly large value */

/* big enough to hold our biggest descriptor */
#define USB_COMP_EP0_BUFSIZ	1024

/* OS feature descriptor length <= 4kB */
#define USB_COMP_EP0_OS_DESC_BUFSIZ	4096

#define USB_MS_TO_HS_INTERVAL(x)	(ilog2((x * 1000 / 125)) + 1)
struct usb_configuration;

/**
 * struct usb_os_desc_ext_prop - describes one "Extended Property"
 * @entry: used to keep a list of extended properties
 * @type: Extended Property type
 * @name_len: Extended Property unicode name length, including terminating '\0'
 * @name: Extended Property name
 * @data_len: Length of Extended Property blob (for unicode store double len)
 * @data: Extended Property blob
 * @item: Represents this Extended Property in configfs
 */
struct usb_os_desc_ext_prop {
	struct list_head	entry;
	u8			type;
	int			name_len;
	char			*name;
	int			data_len;
	char			*data;
	struct config_item	item;
};

/**
 * struct usb_os_desc - describes OS descriptors associated with one interface
 * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
 * @ext_prop: Extended Properties list
 * @ext_prop_len: Total length of Extended Properties blobs
 * @ext_prop_count: Number of Extended Properties
 * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
 * @group: Represents OS descriptors associated with an interface in configfs
 * @owner: Module associated with this OS descriptor
 */
struct usb_os_desc {
	char			*ext_compat_id;
	struct list_head	ext_prop;
	int			ext_prop_len;
	int			ext_prop_count;
	struct mutex		*opts_mutex;
	struct config_group	group;
	struct module		*owner;
};

/**
 * struct usb_os_desc_table - describes OS descriptors associated with one
 * interface of a usb_function
 * @if_id: Interface id
 * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
 *	interface
 *
 * Each interface can have at most one "Extended Compatibility ID" and a
 * number of "Extended Properties".
 */
struct usb_os_desc_table {
	int			if_id;
	struct usb_os_desc	*os_desc;
};

/**
 * struct usb_function - describes one function of a configuration
 * @name: For diagnostics, identifies the function.
 * @strings: tables of strings, keyed by identifiers assigned during bind()
 *	and by language IDs provided in control requests
 * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
 *	string identifiers assigned during @bind().  If this pointer is null,
 *	the function will not be available at full speed (or at low speed).
 * @hs_descriptors: Table of high speed descriptors, using interface and
 *	string identifiers assigned during @bind().  If this pointer is null,
 *	the function will not be available at high speed.
 * @ss_descriptors: Table of super speed descriptors, using interface and
 *	string identifiers assigned during @bind(). If this
 *	pointer is null after initiation, the function will not
 *	be available at super speed.
 * @ssp_descriptors: Table of super speed plus descriptors, using
 *	interface and string identifiers assigned during @bind(). If
 *	this pointer is null after initiation, the function will not
 *	be available at super speed plus.
 * @config: assigned when @usb_add_function() is called; this is the
 *	configuration with which this function is associated.
 * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
 *	can expose more than one interface. If an interface is a member of
 *	an IAD, only the first interface of IAD has its entry in the table.
 * @os_desc_n: Number of entries in os_desc_table
 * @bind: Before the gadget can register, all of its functions bind() to the
 *	available resources including string and interface identifiers used
 *	in interface or class descriptors; endpoints; I/O buffers; and so on.
 * @unbind: Reverses @bind; called as a side effect of unregistering the
 *	driver which added this function.
 * @free_func: free the struct usb_function.
 * @mod: (internal) points to the module that created this structure.
 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
 *	initialize usb_ep.driver data at this time (when it is used).
 *	Note that setting an interface to its current altsetting resets
 *	interface state, and that all interfaces have a disabled state.
 * @get_alt: Returns the active altsetting.  If this is not provided,
 *	then only altsetting zero is supported.
 * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
 *	include host resetting or reconfiguring the gadget, and disconnection.
 * @setup: Used for interface-specific control requests.
 * @req_match: Tests if a given class request can be handled by this function.
 * @suspend: Notifies functions when the host stops sending USB traffic.
 * @resume: Notifies functions when the host restarts USB traffic.
 * @get_status: Returns function status as a reply to
 *	GetStatus() request when the recipient is Interface.
 * @func_suspend: callback to be called when
 *	SetFeature(FUNCTION_SUSPEND) is reseived
 *
 * A single USB function uses one or more interfaces, and should in most
 * cases support operation at both full and high speeds.  Each function is
 * associated by @usb_add_function() with a one configuration; that function
 * causes @bind() to be called so resources can be allocated as part of
 * setting up a gadget driver.  Those resources include endpoints, which
 * should be allocated using @usb_ep_autoconfig().
 *
 * To support dual speed operation, a function driver provides descriptors
 * for both high and full speed operation.  Except in rare cases that don't
 * involve bulk endpoints, each speed needs different endpoint descriptors.
 *
 * Function drivers choose their own strategies for managing instance data.
 * The simplest strategy just declares it "static', which means the function
 * can only be activated once.  If the function needs to be exposed in more
 * than one configuration at a given speed, it needs to support multiple
 * usb_function structures (one for each configuration).
 *
 * A more complex strategy might encapsulate a @usb_function structure inside
 * a driver-specific instance structure to allows multiple activations.  An
 * example of multiple activations might be a CDC ACM function that supports
 * two or more distinct instances within the same configuration, providing
 * several independent logical data links to a USB host.
 */

struct usb_function {
	const char			*name;
	struct usb_gadget_strings	**strings;
	struct usb_descriptor_header	**fs_descriptors;
	struct usb_descriptor_header	**hs_descriptors;
	struct usb_descriptor_header	**ss_descriptors;
	struct usb_descriptor_header	**ssp_descriptors;

	struct usb_configuration	*config;

	struct usb_os_desc_table	*os_desc_table;
	unsigned			os_desc_n;

	/* REVISIT:  bind() functions can be marked __init, which
	 * makes trouble for section mismatch analysis.  See if
	 * we can't restructure things to avoid mismatching.
	 * Related:  unbind() may kfree() but bind() won't...
	 */

	/* configuration management:  bind/unbind */
	int			(*bind)(struct usb_configuration *,
					struct usb_function *);
	void			(*unbind)(struct usb_configuration *,
					struct usb_function *);
	void			(*free_func)(struct usb_function *f);
	struct module		*mod;

	/* runtime state management */
	int			(*set_alt)(struct usb_function *,
					unsigned interface, unsigned alt);
	int			(*get_alt)(struct usb_function *,
					unsigned interface);
	void			(*disable)(struct usb_function *);
	int			(*setup)(struct usb_function *,
					const struct usb_ctrlrequest *);
	bool			(*req_match)(struct usb_function *,
					const struct usb_ctrlrequest *,
					bool config0);
	void			(*suspend)(struct usb_function *);
	void			(*resume)(struct usb_function *);

	/* USB 3.0 additions */
	int			(*get_status)(struct usb_function *);
	int			(*func_suspend)(struct usb_function *,
						u8 suspend_opt);
	/* private: */
	/* internals */
	struct list_head		list;
	DECLARE_BITMAP(endpoints, 32);
	const struct usb_function_instance *fi;

	unsigned int		bind_deactivated:1;
};

int usb_add_function(struct usb_configuration *, struct usb_function *);

int usb_function_deactivate(struct usb_function *);
int usb_function_activate(struct usb_function *);

int usb_interface_id(struct usb_configuration *, struct usb_function *);

int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
			struct usb_ep *_ep);

#define	MAX_CONFIG_INTERFACES		16	/* arbitrary; max 255 */

/**
 * struct usb_configuration - represents one gadget configuration
 * @label: For diagnostics, describes the configuration.
 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
 *	and by language IDs provided in control requests.
 * @descriptors: Table of descriptors preceding all function descriptors.
 *	Examples include OTG and vendor-specific descriptors.
 * @unbind: Reverses @bind; called as a side effect of unregistering the
 *	driver which added this configuration.
 * @setup: Used to delegate control requests that aren't handled by standard
 *	device infrastructure or directed at a specific interface.
 * @bConfigurationValue: Copied into configuration descriptor.
 * @iConfiguration: Copied into configuration descriptor.
 * @bmAttributes: Copied into configuration descriptor.
 * @MaxPower: Power consumtion in mA. Used to compute bMaxPower in the
 *	configuration descriptor after considering the bus speed.
 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
 *	the device associated with this configuration.
 *
 * Configurations are building blocks for gadget drivers structured around
 * function drivers.  Simple USB gadgets require only one function and one
 * configuration, and handle dual-speed hardware by always providing the same
 * functionality.  Slightly more complex gadgets may have more than one
 * single-function configuration at a given speed; or have configurations
 * that only work at one speed.
 *
 * Composite devices are, by definition, ones with configurations which
 * include more than one function.
 *
 * The lifecycle of a usb_configuration includes allocation, initialization
 * of the fields described above, and calling @usb_add_config() to set up
 * internal data and bind it to a specific device.  The configuration's
 * @bind() method is then used to initialize all the functions and then
 * call @usb_add_function() for them.
 *
 * Those functions would normally be independent of each other, but that's
 * not mandatory.  CDC WMC devices are an example where functions often
 * depend on other functions, with some functions subsidiary to others.
 * Such interdependency may be managed in any way, so long as all of the
 * descriptors complete by the time the composite driver returns from
 * its bind() routine.
 */
struct usb_configuration {
	const char			*label;
	struct usb_gadget_strings	**strings;
	const struct usb_descriptor_header **descriptors;

	/* REVISIT:  bind() functions can be marked __init, which
	 * makes trouble for section mismatch analysis.  See if
	 * we can't restructure things to avoid mismatching...
	 */

	/* configuration management: unbind/setup */
	void			(*unbind)(struct usb_configuration *);
	int			(*setup)(struct usb_configuration *,
					const struct usb_ctrlrequest *);

	/* fields in the config descriptor */
	u8			bConfigurationValue;
	u8			iConfiguration;
	u8			bmAttributes;
	u16			MaxPower;

	struct usb_composite_dev	*cdev;

	/* private: */
	/* internals */
	struct list_head	list;
	struct list_head	functions;
	u8			next_interface_id;
	unsigned		superspeed:1;
	unsigned		highspeed:1;
	unsigned		fullspeed:1;
	unsigned		superspeed_plus:1;
	struct usb_function	*interface[MAX_CONFIG_INTERFACES];
};

int usb_add_config(struct usb_composite_dev *,
		struct usb_configuration *,
		int (*)(struct usb_configuration *));

void usb_remove_config(struct usb_composite_dev *,
		struct usb_configuration *);

/* predefined index for usb_composite_driver */
enum {
	USB_GADGET_MANUFACTURER_IDX	= 0,
	USB_GADGET_PRODUCT_IDX,
	USB_GADGET_SERIAL_IDX,
	USB_GADGET_FIRST_AVAIL_IDX,
};

/**
 * struct usb_composite_driver - groups configurations into a gadget
 * @name: For diagnostics, identifies the driver.
 * @dev: Template descriptor for the device, including default device
 *	identifiers.
 * @strings: tables of strings, keyed by identifiers assigned during @bind
 *	and language IDs provided in control requests. Note: The first entries
 *	are predefined. The first entry that may be used is
 *	USB_GADGET_FIRST_AVAIL_IDX
 * @max_speed: Highest speed the driver supports.
 * @needs_serial: set to 1 if the gadget needs userspace to provide
 * 	a serial number.  If one is not provided, warning will be printed.
 * @bind: (REQUIRED) Used to allocate resources that are shared across the
 *	whole device, such as string IDs, and add its configurations using
 *	@usb_add_config(). This may fail by returning a negative errno
 *	value; it should return zero on successful initialization.
 * @unbind: Reverses @bind; called as a side effect of unregistering
 *	this driver.
 * @disconnect: optional driver disconnect method
 * @suspend: Notifies when the host stops sending USB traffic,
 *	after function notifications
 * @resume: Notifies configuration when the host restarts USB traffic,
 *	before function notifications
 * @gadget_driver: Gadget driver controlling this driver
 *
 * Devices default to reporting self powered operation.  Devices which rely
 * on bus powered operation should report this in their @bind method.
 *
 * Before returning from @bind, various fields in the template descriptor
 * may be overridden.  These include the idVendor/idProduct/bcdDevice values
 * normally to bind the appropriate host side driver, and the three strings
 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
 * meaningful device identifiers.  (The strings will not be defined unless
 * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
 * is also reported, as defined by the underlying controller driver.
 */
struct usb_composite_driver {
	const char				*name;
	const struct usb_device_descriptor	*dev;
	struct usb_gadget_strings		**strings;
	enum usb_device_speed			max_speed;
	unsigned		needs_serial:1;

	int			(*bind)(struct usb_composite_dev *cdev);
	int			(*unbind)(struct usb_composite_dev *);

	void			(*disconnect)(struct usb_composite_dev *);

	/* global suspend hooks */
	void			(*suspend)(struct usb_composite_dev *);
	void			(*resume)(struct usb_composite_dev *);
	struct usb_gadget_driver		gadget_driver;
};

extern int usb_composite_probe(struct usb_composite_driver *driver);
extern void usb_composite_unregister(struct usb_composite_driver *driver);

/**
 * module_usb_composite_driver() - Helper macro for registering a USB gadget
 * composite driver
 * @__usb_composite_driver: usb_composite_driver struct
 *
 * Helper macro for USB gadget composite drivers which do not do anything
 * special in module init/exit. This eliminates a lot of boilerplate. Each
 * module may only use this macro once, and calling it replaces module_init()
 * and module_exit()
 */
#define module_usb_composite_driver(__usb_composite_driver) \
	module_driver(__usb_composite_driver, usb_composite_probe, \
		       usb_composite_unregister)

extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
extern int composite_dev_prepare(struct usb_composite_driver *composite,
		struct usb_composite_dev *cdev);
extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
					 struct usb_ep *ep0);
void composite_dev_cleanup(struct usb_composite_dev *cdev);

static inline struct usb_composite_driver *to_cdriver(
		struct usb_gadget_driver *gdrv)
{
	return container_of(gdrv, struct usb_composite_driver, gadget_driver);
}

#define OS_STRING_QW_SIGN_LEN		14
#define OS_STRING_IDX			0xEE

/**
 * struct usb_composite_device - represents one composite usb gadget
 * @gadget: read-only, abstracts the gadget's usb peripheral controller
 * @req: used for control responses; buffer is pre-allocated
 * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
 * @config: the currently active configuration
 * @qw_sign: qwSignature part of the OS string
 * @b_vendor_code: bMS_VendorCode part of the OS string
 * @use_os_string: false by default, interested gadgets set it
 * @os_desc_config: the configuration to be used with OS descriptors
 * @setup_pending: true when setup request is queued but not completed
 * @os_desc_pending: true when os_desc request is queued but not completed
 *
 * One of these devices is allocated and initialized before the
 * associated device driver's bind() is called.
 *
 * OPEN ISSUE:  it appears that some WUSB devices will need to be
 * built by combining a normal (wired) gadget with a wireless one.
 * This revision of the gadget framework should probably try to make
 * sure doing that won't hurt too much.
 *
 * One notion for how to handle Wireless USB devices involves:
 *
 * (a) a second gadget here, discovery mechanism TBD, but likely
 *     needing separate "register/unregister WUSB gadget" calls;
 * (b) updates to usb_gadget to include flags "is it wireless",
 *     "is it wired", plus (presumably in a wrapper structure)
 *     bandgroup and PHY info;
 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
 *     wireless-specific parameters like maxburst and maxsequence;
 * (d) configurations that are specific to wireless links;
 * (e) function drivers that understand wireless configs and will
 *     support wireless for (additional) function instances;
 * (f) a function to support association setup (like CBAF), not
 *     necessarily requiring a wireless adapter;
 * (g) composite device setup that can create one or more wireless
 *     configs, including appropriate association setup support;
 * (h) more, TBD.
 */
struct usb_composite_dev {
	struct usb_gadget		*gadget;
	struct usb_request		*req;
	struct usb_request		*os_desc_req;

	struct usb_configuration	*config;

	/* OS String is a custom (yet popular) extension to the USB standard. */
	u8				qw_sign[OS_STRING_QW_SIGN_LEN];
	u8				b_vendor_code;
	struct usb_configuration	*os_desc_config;
	unsigned int			use_os_string:1;

	/* private: */
	/* internals */
	unsigned int			suspended:1;
	struct usb_device_descriptor	desc;
	struct list_head		configs;
	struct list_head		gstrings;
	struct usb_composite_driver	*driver;
	u8				next_string_id;
	char				*def_manufacturer;

	/* the gadget driver won't enable the data pullup
	 * while the deactivation count is nonzero.
	 */
	unsigned			deactivations;

	/* the composite driver won't complete the control transfer's
	 * data/status stages till delayed_status is zero.
	 */
	int				delayed_status;

	/* protects deactivations and delayed_status counts*/
	spinlock_t			lock;

	/* public: */
	unsigned int			setup_pending:1;
	unsigned int			os_desc_pending:1;
};

extern int usb_string_id(struct usb_composite_dev *c);
extern int usb_string_ids_tab(struct usb_composite_dev *c,
			      struct usb_string *str);
extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
		struct usb_gadget_strings **sp, unsigned n_strings);

extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);

extern void composite_disconnect(struct usb_gadget *gadget);
extern int composite_setup(struct usb_gadget *gadget,
		const struct usb_ctrlrequest *ctrl);
extern void composite_suspend(struct usb_gadget *gadget);
extern void composite_resume(struct usb_gadget *gadget);

/*
 * Some systems will need runtime overrides for the  product identifiers
 * published in the device descriptor, either numbers or strings or both.
 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
 */
struct usb_composite_overwrite {
	u16	idVendor;
	u16	idProduct;
	u16	bcdDevice;
	char	*serial_number;
	char	*manufacturer;
	char	*product;
};
#define USB_GADGET_COMPOSITE_OPTIONS()					\
	static struct usb_composite_overwrite coverwrite;		\
									\
	module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
	MODULE_PARM_DESC(idVendor, "USB Vendor ID");			\
									\
	module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
									\
	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
									\
	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
			S_IRUGO); \
	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");		\
									\
	module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
			S_IRUGO); \
	MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");	\
									\
	module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
	MODULE_PARM_DESC(iProduct, "USB Product string")

void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
		struct usb_composite_overwrite *covr);

static inline u16 get_default_bcdDevice(void)
{
	u16 bcdDevice;

	bcdDevice = bin2bcd((LINUX_VERSION_CODE >> 16 & 0xff)) << 8;
	bcdDevice |= bin2bcd((LINUX_VERSION_CODE >> 8 & 0xff));
	return bcdDevice;
}

struct usb_function_driver {
	const char *name;
	struct module *mod;
	struct list_head list;
	struct usb_function_instance *(*alloc_inst)(void);
	struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
};

struct usb_function_instance {
	struct config_group group;
	struct list_head cfs_list;
	struct usb_function_driver *fd;
	int (*set_inst_name)(struct usb_function_instance *inst,
			      const char *name);
	void (*free_func_inst)(struct usb_function_instance *inst);
};

void usb_function_unregister(struct usb_function_driver *f);
int usb_function_register(struct usb_function_driver *newf);
void usb_put_function_instance(struct usb_function_instance *fi);
void usb_put_function(struct usb_function *f);
struct usb_function_instance *usb_get_function_instance(const char *name);
struct usb_function *usb_get_function(struct usb_function_instance *fi);

struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
		int val);
int usb_add_config_only(struct usb_composite_dev *cdev,
		struct usb_configuration *config);
void usb_remove_function(struct usb_configuration *c, struct usb_function *f);

#define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
	static struct usb_function_driver _name ## usb_func = {		\
		.name = __stringify(_name),				\
		.mod  = THIS_MODULE,					\
		.alloc_inst = _inst_alloc,				\
		.alloc_func = _func_alloc,				\
	};								\
	MODULE_ALIAS("usbfunc:"__stringify(_name));

#define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc)	\
	DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
	static int __init _name ## mod_init(void)			\
	{								\
		return usb_function_register(&_name ## usb_func);	\
	}								\
	static void __exit _name ## mod_exit(void)			\
	{								\
		usb_function_unregister(&_name ## usb_func);		\
	}								\
	module_init(_name ## mod_init);					\
	module_exit(_name ## mod_exit)

/* messaging utils */
#define DBG(d, fmt, args...) \
	dev_dbg(&(d)->gadget->dev , fmt , ## args)
#define VDBG(d, fmt, args...) \
	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
#define ERROR(d, fmt, args...) \
	dev_err(&(d)->gadget->dev , fmt , ## args)
#define WARNING(d, fmt, args...) \
	dev_warn(&(d)->gadget->dev , fmt , ## args)
#define INFO(d, fmt, args...) \
	dev_info(&(d)->gadget->dev , fmt , ## args)

#endif	/* __LINUX_USB_COMPOSITE_H */