summaryrefslogtreecommitdiffstats
path: root/include/linux/usb/composite.h
blob: 9ff1e465d307727ec46466a5a5fe002bb5af92a2 (plain)
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
/*
 * 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

#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 *);
	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;
	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;

	unsigned			setup_pending:1;
	unsigned			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 */