xref: /linux/include/linux/usb/composite.h (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * composite.h -- framework for usb gadgets which are composite devices
4  *
5  * Copyright (C) 2006-2008 David Brownell
6  */
7 
8 #ifndef	__LINUX_USB_COMPOSITE_H
9 #define	__LINUX_USB_COMPOSITE_H
10 
11 /*
12  * This framework is an optional layer on top of the USB Gadget interface,
13  * making it easier to build (a) Composite devices, supporting multiple
14  * functions within any single configuration, and (b) Multi-configuration
15  * devices, also supporting multiple functions but without necessarily
16  * having more than one function per configuration.
17  *
18  * Example:  a device with a single configuration supporting both network
19  * link and mass storage functions is a composite device.  Those functions
20  * might alternatively be packaged in individual configurations, but in
21  * the composite model the host can use both functions at the same time.
22  */
23 
24 #include <linux/bcd.h>
25 #include <linux/version.h>
26 #include <linux/usb/ch9.h>
27 #include <linux/usb/gadget.h>
28 #include <linux/usb/webusb.h>
29 #include <linux/log2.h>
30 #include <linux/configfs.h>
31 
32 /*
33  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
34  * wish to delay the data/status stages of the control transfer till they
35  * are ready. The control transfer will then be kept from completing till
36  * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
37  * invoke usb_composite_setup_continue().
38  *
39  * NOTE: USB_GADGET_DELAYED_STATUS must not be used in UDC drivers: they
40  * must delay completing the status stage for 0-length control transfers
41  * regardless of the whether USB_GADGET_DELAYED_STATUS is returned from
42  * the gadget driver's setup() callback.
43  * Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS,
44  * which is a bug. These drivers must be fixed and USB_GADGET_DELAYED_STATUS
45  * must be contained within the composite framework.
46  */
47 #define USB_GADGET_DELAYED_STATUS       0x7fff	/* Impossibly large value */
48 
49 /* big enough to hold our biggest descriptor */
50 #define USB_COMP_EP0_BUFSIZ	4096
51 
52 /* OS feature descriptor length <= 4kB */
53 #define USB_COMP_EP0_OS_DESC_BUFSIZ	4096
54 
55 #define USB_MS_TO_HS_INTERVAL(x)	(ilog2((x * 1000 / 125)) + 1)
56 struct usb_configuration;
57 
58 /**
59  * struct usb_os_desc_ext_prop - describes one "Extended Property"
60  * @entry: used to keep a list of extended properties
61  * @type: Extended Property type
62  * @name_len: Extended Property unicode name length, including terminating '\0'
63  * @name: Extended Property name
64  * @data_len: Length of Extended Property blob (for unicode store double len)
65  * @data: Extended Property blob
66  * @item: Represents this Extended Property in configfs
67  */
68 struct usb_os_desc_ext_prop {
69 	struct list_head	entry;
70 	u8			type;
71 	int			name_len;
72 	char			*name;
73 	int			data_len;
74 	char			*data;
75 	struct config_item	item;
76 };
77 
78 /**
79  * struct usb_os_desc - describes OS descriptors associated with one interface
80  * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
81  * @ext_prop: Extended Properties list
82  * @ext_prop_len: Total length of Extended Properties blobs
83  * @ext_prop_count: Number of Extended Properties
84  * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
85  * @group: Represents OS descriptors associated with an interface in configfs
86  * @owner: Module associated with this OS descriptor
87  */
88 struct usb_os_desc {
89 	char			*ext_compat_id;
90 	struct list_head	ext_prop;
91 	int			ext_prop_len;
92 	int			ext_prop_count;
93 	struct mutex		*opts_mutex;
94 	struct config_group	group;
95 	struct module		*owner;
96 };
97 
98 /**
99  * struct usb_os_desc_table - describes OS descriptors associated with one
100  * interface of a usb_function
101  * @if_id: Interface id
102  * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
103  *	interface
104  *
105  * Each interface can have at most one "Extended Compatibility ID" and a
106  * number of "Extended Properties".
107  */
108 struct usb_os_desc_table {
109 	int			if_id;
110 	struct usb_os_desc	*os_desc;
111 };
112 
113 /**
114  * struct usb_function - describes one function of a configuration
115  * @name: For diagnostics, identifies the function.
116  * @strings: tables of strings, keyed by identifiers assigned during bind()
117  *	and by language IDs provided in control requests
118  * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
119  *	string identifiers assigned during @bind().  If this pointer is null,
120  *	the function will not be available at full speed (or at low speed).
121  * @hs_descriptors: Table of high speed descriptors, using interface and
122  *	string identifiers assigned during @bind().  If this pointer is null,
123  *	the function will not be available at high speed.
124  * @ss_descriptors: Table of super speed descriptors, using interface and
125  *	string identifiers assigned during @bind(). If this
126  *	pointer is null after initiation, the function will not
127  *	be available at super speed.
128  * @ssp_descriptors: Table of super speed plus descriptors, using
129  *	interface and string identifiers assigned during @bind(). If
130  *	this pointer is null after initiation, the function will not
131  *	be available at super speed plus.
132  * @config: assigned when @usb_add_function() is called; this is the
133  *	configuration with which this function is associated.
134  * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
135  *	can expose more than one interface. If an interface is a member of
136  *	an IAD, only the first interface of IAD has its entry in the table.
137  * @os_desc_n: Number of entries in os_desc_table
138  * @bind: Before the gadget can register, all of its functions bind() to the
139  *	available resources including string and interface identifiers used
140  *	in interface or class descriptors; endpoints; I/O buffers; and so on.
141  * @unbind: Reverses @bind; called as a side effect of unregistering the
142  *	driver which added this function.
143  * @free_func: free the struct usb_function.
144  * @mod: (internal) points to the module that created this structure.
145  * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
146  *	initialize usb_ep.driver data at this time (when it is used).
147  *	Note that setting an interface to its current altsetting resets
148  *	interface state, and that all interfaces have a disabled state.
149  * @get_alt: Returns the active altsetting.  If this is not provided,
150  *	then only altsetting zero is supported.
151  * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
152  *	include host resetting or reconfiguring the gadget, and disconnection.
153  * @setup: Used for interface-specific control requests.
154  * @req_match: Tests if a given class request can be handled by this function.
155  * @suspend: Notifies functions when the host stops sending USB traffic.
156  * @resume: Notifies functions when the host restarts USB traffic.
157  * @get_status: Returns function status as a reply to
158  *	GetStatus() request when the recipient is Interface.
159  * @func_suspend: callback to be called when
160  *	SetFeature(FUNCTION_SUSPEND) is reseived
161  * @func_suspended: Indicates whether the function is in function suspend state.
162  * @func_wakeup_armed: Indicates whether the function is armed by the host for
163  *	wakeup signaling.
164  *
165  * A single USB function uses one or more interfaces, and should in most
166  * cases support operation at both full and high speeds.  Each function is
167  * associated by @usb_add_function() with a one configuration; that function
168  * causes @bind() to be called so resources can be allocated as part of
169  * setting up a gadget driver.  Those resources include endpoints, which
170  * should be allocated using @usb_ep_autoconfig().
171  *
172  * To support dual speed operation, a function driver provides descriptors
173  * for both high and full speed operation.  Except in rare cases that don't
174  * involve bulk endpoints, each speed needs different endpoint descriptors.
175  *
176  * Function drivers choose their own strategies for managing instance data.
177  * The simplest strategy just declares it "static', which means the function
178  * can only be activated once.  If the function needs to be exposed in more
179  * than one configuration at a given speed, it needs to support multiple
180  * usb_function structures (one for each configuration).
181  *
182  * A more complex strategy might encapsulate a @usb_function structure inside
183  * a driver-specific instance structure to allows multiple activations.  An
184  * example of multiple activations might be a CDC ACM function that supports
185  * two or more distinct instances within the same configuration, providing
186  * several independent logical data links to a USB host.
187  */
188 
189 struct usb_function {
190 	const char			*name;
191 	struct usb_gadget_strings	**strings;
192 	struct usb_descriptor_header	**fs_descriptors;
193 	struct usb_descriptor_header	**hs_descriptors;
194 	struct usb_descriptor_header	**ss_descriptors;
195 	struct usb_descriptor_header	**ssp_descriptors;
196 
197 	struct usb_configuration	*config;
198 
199 	struct usb_os_desc_table	*os_desc_table;
200 	unsigned			os_desc_n;
201 
202 	/* REVISIT:  bind() functions can be marked __init, which
203 	 * makes trouble for section mismatch analysis.  See if
204 	 * we can't restructure things to avoid mismatching.
205 	 * Related:  unbind() may kfree() but bind() won't...
206 	 */
207 
208 	/* configuration management:  bind/unbind */
209 	int			(*bind)(struct usb_configuration *,
210 					struct usb_function *);
211 	void			(*unbind)(struct usb_configuration *,
212 					struct usb_function *);
213 	void			(*free_func)(struct usb_function *f);
214 	struct module		*mod;
215 
216 	/* runtime state management */
217 	int			(*set_alt)(struct usb_function *,
218 					unsigned interface, unsigned alt);
219 	int			(*get_alt)(struct usb_function *,
220 					unsigned interface);
221 	void			(*disable)(struct usb_function *);
222 	int			(*setup)(struct usb_function *,
223 					const struct usb_ctrlrequest *);
224 	bool			(*req_match)(struct usb_function *,
225 					const struct usb_ctrlrequest *,
226 					bool config0);
227 	void			(*suspend)(struct usb_function *);
228 	void			(*resume)(struct usb_function *);
229 
230 	/* USB 3.0 additions */
231 	int			(*get_status)(struct usb_function *);
232 	int			(*func_suspend)(struct usb_function *,
233 						u8 suspend_opt);
234 	bool			func_suspended;
235 	bool			func_wakeup_armed;
236 	/* private: */
237 	/* internals */
238 	struct list_head		list;
239 	DECLARE_BITMAP(endpoints, 32);
240 	const struct usb_function_instance *fi;
241 
242 	unsigned int		bind_deactivated:1;
243 };
244 
245 int usb_add_function(struct usb_configuration *, struct usb_function *);
246 
247 int usb_function_deactivate(struct usb_function *);
248 int usb_function_activate(struct usb_function *);
249 
250 int usb_interface_id(struct usb_configuration *, struct usb_function *);
251 
252 int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
253 				struct usb_ep *_ep, u8 alt);
254 
255 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
256 			struct usb_ep *_ep);
257 int usb_func_wakeup(struct usb_function *func);
258 
259 #define	MAX_CONFIG_INTERFACES		32
260 
261 /**
262  * struct usb_configuration - represents one gadget configuration
263  * @label: For diagnostics, describes the configuration.
264  * @strings: Tables of strings, keyed by identifiers assigned during @bind()
265  *	and by language IDs provided in control requests.
266  * @descriptors: Table of descriptors preceding all function descriptors.
267  *	Examples include OTG and vendor-specific descriptors.
268  * @unbind: Reverses @bind; called as a side effect of unregistering the
269  *	driver which added this configuration.
270  * @setup: Used to delegate control requests that aren't handled by standard
271  *	device infrastructure or directed at a specific interface.
272  * @bConfigurationValue: Copied into configuration descriptor.
273  * @iConfiguration: Copied into configuration descriptor.
274  * @bmAttributes: Copied into configuration descriptor.
275  * @MaxPower: Power consumption in mA. Used to compute bMaxPower in the
276  *	configuration descriptor after considering the bus speed.
277  * @cdev: assigned by @usb_add_config() before calling @bind(); this is
278  *	the device associated with this configuration.
279  *
280  * Configurations are building blocks for gadget drivers structured around
281  * function drivers.  Simple USB gadgets require only one function and one
282  * configuration, and handle dual-speed hardware by always providing the same
283  * functionality.  Slightly more complex gadgets may have more than one
284  * single-function configuration at a given speed; or have configurations
285  * that only work at one speed.
286  *
287  * Composite devices are, by definition, ones with configurations which
288  * include more than one function.
289  *
290  * The lifecycle of a usb_configuration includes allocation, initialization
291  * of the fields described above, and calling @usb_add_config() to set up
292  * internal data and bind it to a specific device.  The configuration's
293  * @bind() method is then used to initialize all the functions and then
294  * call @usb_add_function() for them.
295  *
296  * Those functions would normally be independent of each other, but that's
297  * not mandatory.  CDC WMC devices are an example where functions often
298  * depend on other functions, with some functions subsidiary to others.
299  * Such interdependency may be managed in any way, so long as all of the
300  * descriptors complete by the time the composite driver returns from
301  * its bind() routine.
302  */
303 struct usb_configuration {
304 	const char			*label;
305 	struct usb_gadget_strings	**strings;
306 	const struct usb_descriptor_header **descriptors;
307 
308 	/* REVISIT:  bind() functions can be marked __init, which
309 	 * makes trouble for section mismatch analysis.  See if
310 	 * we can't restructure things to avoid mismatching...
311 	 */
312 
313 	/* configuration management: unbind/setup */
314 	void			(*unbind)(struct usb_configuration *);
315 	int			(*setup)(struct usb_configuration *,
316 					const struct usb_ctrlrequest *);
317 
318 	/* fields in the config descriptor */
319 	u8			bConfigurationValue;
320 	u8			iConfiguration;
321 	u8			bmAttributes;
322 	u16			MaxPower;
323 
324 	struct usb_composite_dev	*cdev;
325 
326 	/* private: */
327 	/* internals */
328 	struct list_head	list;
329 	struct list_head	functions;
330 	u8			next_interface_id;
331 	unsigned		superspeed:1;
332 	unsigned		highspeed:1;
333 	unsigned		fullspeed:1;
334 	unsigned		superspeed_plus:1;
335 	struct usb_function	*interface[MAX_CONFIG_INTERFACES];
336 };
337 
338 int usb_add_config(struct usb_composite_dev *,
339 		struct usb_configuration *,
340 		int (*)(struct usb_configuration *));
341 
342 void usb_remove_config(struct usb_composite_dev *,
343 		struct usb_configuration *);
344 
345 /* predefined index for usb_composite_driver */
346 enum {
347 	USB_GADGET_MANUFACTURER_IDX	= 0,
348 	USB_GADGET_PRODUCT_IDX,
349 	USB_GADGET_SERIAL_IDX,
350 	USB_GADGET_FIRST_AVAIL_IDX,
351 };
352 
353 /**
354  * struct usb_composite_driver - groups configurations into a gadget
355  * @name: For diagnostics, identifies the driver.
356  * @dev: Template descriptor for the device, including default device
357  *	identifiers.
358  * @strings: tables of strings, keyed by identifiers assigned during @bind
359  *	and language IDs provided in control requests. Note: The first entries
360  *	are predefined. The first entry that may be used is
361  *	USB_GADGET_FIRST_AVAIL_IDX
362  * @max_speed: Highest speed the driver supports.
363  * @needs_serial: set to 1 if the gadget needs userspace to provide
364  * 	a serial number.  If one is not provided, warning will be printed.
365  * @bind: (REQUIRED) Used to allocate resources that are shared across the
366  *	whole device, such as string IDs, and add its configurations using
367  *	@usb_add_config(). This may fail by returning a negative errno
368  *	value; it should return zero on successful initialization.
369  * @unbind: Reverses @bind; called as a side effect of unregistering
370  *	this driver.
371  * @disconnect: optional driver disconnect method
372  * @suspend: Notifies when the host stops sending USB traffic,
373  *	after function notifications
374  * @resume: Notifies configuration when the host restarts USB traffic,
375  *	before function notifications
376  * @gadget_driver: Gadget driver controlling this driver
377  *
378  * Devices default to reporting self powered operation.  Devices which rely
379  * on bus powered operation should report this in their @bind method.
380  *
381  * Before returning from @bind, various fields in the template descriptor
382  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
383  * normally to bind the appropriate host side driver, and the three strings
384  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
385  * meaningful device identifiers.  (The strings will not be defined unless
386  * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
387  * is also reported, as defined by the underlying controller driver.
388  */
389 struct usb_composite_driver {
390 	const char				*name;
391 	const struct usb_device_descriptor	*dev;
392 	struct usb_gadget_strings		**strings;
393 	enum usb_device_speed			max_speed;
394 	unsigned		needs_serial:1;
395 
396 	int			(*bind)(struct usb_composite_dev *cdev);
397 	int			(*unbind)(struct usb_composite_dev *);
398 
399 	void			(*disconnect)(struct usb_composite_dev *);
400 
401 	/* global suspend hooks */
402 	void			(*suspend)(struct usb_composite_dev *);
403 	void			(*resume)(struct usb_composite_dev *);
404 	struct usb_gadget_driver		gadget_driver;
405 };
406 
407 extern int usb_composite_probe(struct usb_composite_driver *driver);
408 extern void usb_composite_unregister(struct usb_composite_driver *driver);
409 
410 /**
411  * module_usb_composite_driver() - Helper macro for registering a USB gadget
412  * composite driver
413  * @__usb_composite_driver: usb_composite_driver struct
414  *
415  * Helper macro for USB gadget composite drivers which do not do anything
416  * special in module init/exit. This eliminates a lot of boilerplate. Each
417  * module may only use this macro once, and calling it replaces module_init()
418  * and module_exit()
419  */
420 #define module_usb_composite_driver(__usb_composite_driver) \
421 	module_driver(__usb_composite_driver, usb_composite_probe, \
422 		       usb_composite_unregister)
423 
424 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
425 extern int composite_dev_prepare(struct usb_composite_driver *composite,
426 		struct usb_composite_dev *cdev);
427 extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
428 					 struct usb_ep *ep0);
429 void composite_dev_cleanup(struct usb_composite_dev *cdev);
430 void check_remote_wakeup_config(struct usb_gadget *g,
431 				struct usb_configuration *c);
432 
to_cdriver(struct usb_gadget_driver * gdrv)433 static inline struct usb_composite_driver *to_cdriver(
434 		struct usb_gadget_driver *gdrv)
435 {
436 	return container_of(gdrv, struct usb_composite_driver, gadget_driver);
437 }
438 
439 #define OS_STRING_QW_SIGN_LEN		14
440 #define OS_STRING_IDX			0xEE
441 
442 /**
443  * struct usb_composite_dev - represents one composite usb gadget
444  * @gadget: read-only, abstracts the gadget's usb peripheral controller
445  * @req: used for control responses; buffer is pre-allocated
446  * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
447  * @config: the currently active configuration
448  * @qw_sign: qwSignature part of the OS string
449  * @b_vendor_code: bMS_VendorCode part of the OS string
450  * @use_os_string: false by default, interested gadgets set it
451  * @bcd_webusb_version: 0x0100 by default, WebUSB specification version
452  * @b_webusb_vendor_code: 0x0 by default, vendor code for WebUSB
453  * @landing_page: empty by default, landing page to announce in WebUSB
454  * @use_webusb: false by default, interested gadgets set it
455  * @os_desc_config: the configuration to be used with OS descriptors
456  * @setup_pending: true when setup request is queued but not completed
457  * @os_desc_pending: true when os_desc request is queued but not completed
458  *
459  * One of these devices is allocated and initialized before the
460  * associated device driver's bind() is called.
461  */
462 struct usb_composite_dev {
463 	struct usb_gadget		*gadget;
464 	struct usb_request		*req;
465 	struct usb_request		*os_desc_req;
466 
467 	struct usb_configuration	*config;
468 
469 	/* OS String is a custom (yet popular) extension to the USB standard. */
470 	u8				qw_sign[OS_STRING_QW_SIGN_LEN];
471 	u8				b_vendor_code;
472 	struct usb_configuration	*os_desc_config;
473 	unsigned int			use_os_string:1;
474 
475 	/* WebUSB */
476 	u16				bcd_webusb_version;
477 	u8				b_webusb_vendor_code;
478 	char				landing_page[WEBUSB_URL_RAW_MAX_LENGTH];
479 	unsigned int			use_webusb:1;
480 
481 	/* private: */
482 	/* internals */
483 	unsigned int			suspended:1;
484 	struct usb_device_descriptor	desc;
485 	struct list_head		configs;
486 	struct list_head		gstrings;
487 	struct usb_composite_driver	*driver;
488 	u8				next_string_id;
489 	char				*def_manufacturer;
490 	struct usb_string		*usb_strings;
491 
492 	/* the gadget driver won't enable the data pullup
493 	 * while the deactivation count is nonzero.
494 	 */
495 	unsigned			deactivations;
496 
497 	/* the composite driver won't complete the control transfer's
498 	 * data/status stages till delayed_status is zero.
499 	 */
500 	int				delayed_status;
501 
502 	/* protects deactivations and delayed_status counts*/
503 	spinlock_t			lock;
504 
505 	/* public: */
506 	unsigned int			setup_pending:1;
507 	unsigned int			os_desc_pending:1;
508 };
509 
510 extern int usb_string_id(struct usb_composite_dev *c);
511 extern int usb_string_ids_tab(struct usb_composite_dev *c,
512 			      struct usb_string *str);
513 extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
514 		struct usb_gadget_strings **sp, unsigned n_strings);
515 
516 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
517 
518 extern void composite_disconnect(struct usb_gadget *gadget);
519 extern void composite_reset(struct usb_gadget *gadget);
520 
521 extern int composite_setup(struct usb_gadget *gadget,
522 		const struct usb_ctrlrequest *ctrl);
523 extern void composite_suspend(struct usb_gadget *gadget);
524 extern void composite_resume(struct usb_gadget *gadget);
525 
526 /*
527  * Some systems will need runtime overrides for the  product identifiers
528  * published in the device descriptor, either numbers or strings or both.
529  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
530  */
531 struct usb_composite_overwrite {
532 	u16	idVendor;
533 	u16	idProduct;
534 	u16	bcdDevice;
535 	char	*serial_number;
536 	char	*manufacturer;
537 	char	*product;
538 };
539 #define USB_GADGET_COMPOSITE_OPTIONS()					\
540 	static struct usb_composite_overwrite coverwrite;		\
541 									\
542 	module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
543 	MODULE_PARM_DESC(idVendor, "USB Vendor ID");			\
544 									\
545 	module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
546 	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
547 									\
548 	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
549 	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
550 									\
551 	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
552 			S_IRUGO); \
553 	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");		\
554 									\
555 	module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
556 			S_IRUGO); \
557 	MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");	\
558 									\
559 	module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
560 	MODULE_PARM_DESC(iProduct, "USB Product string")
561 
562 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
563 		struct usb_composite_overwrite *covr);
564 
get_default_bcdDevice(void)565 static inline u16 get_default_bcdDevice(void)
566 {
567 	u16 bcdDevice;
568 
569 	bcdDevice = bin2bcd(LINUX_VERSION_MAJOR) << 8;
570 	bcdDevice |= bin2bcd(LINUX_VERSION_PATCHLEVEL);
571 	return bcdDevice;
572 }
573 
574 struct usb_function_driver {
575 	const char *name;
576 	struct module *mod;
577 	struct list_head list;
578 	struct usb_function_instance *(*alloc_inst)(void);
579 	struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
580 };
581 
582 struct usb_function_instance {
583 	struct config_group group;
584 	struct list_head cfs_list;
585 	struct usb_function_driver *fd;
586 	int (*set_inst_name)(struct usb_function_instance *inst,
587 			      const char *name);
588 	void (*free_func_inst)(struct usb_function_instance *inst);
589 };
590 
591 void usb_function_unregister(struct usb_function_driver *f);
592 int usb_function_register(struct usb_function_driver *newf);
593 void usb_put_function_instance(struct usb_function_instance *fi);
594 void usb_put_function(struct usb_function *f);
595 struct usb_function_instance *usb_get_function_instance(const char *name);
596 struct usb_function *usb_get_function(struct usb_function_instance *fi);
597 
598 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
599 		int val);
600 int usb_add_config_only(struct usb_composite_dev *cdev,
601 		struct usb_configuration *config);
602 void usb_remove_function(struct usb_configuration *c, struct usb_function *f);
603 
604 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
605 	static struct usb_function_driver _name ## usb_func = {		\
606 		.name = __stringify(_name),				\
607 		.mod  = THIS_MODULE,					\
608 		.alloc_inst = _inst_alloc,				\
609 		.alloc_func = _func_alloc,				\
610 	};								\
611 	MODULE_ALIAS("usbfunc:"__stringify(_name));
612 
613 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc)	\
614 	DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
615 	static int __init _name ## mod_init(void)			\
616 	{								\
617 		return usb_function_register(&_name ## usb_func);	\
618 	}								\
619 	static void __exit _name ## mod_exit(void)			\
620 	{								\
621 		usb_function_unregister(&_name ## usb_func);		\
622 	}								\
623 	module_init(_name ## mod_init);					\
624 	module_exit(_name ## mod_exit)
625 
626 /* messaging utils */
627 #define DBG(d, fmt, args...) \
628 	dev_dbg(&(d)->gadget->dev , fmt , ## args)
629 #define VDBG(d, fmt, args...) \
630 	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
631 #define ERROR(d, fmt, args...) \
632 	dev_err(&(d)->gadget->dev , fmt , ## args)
633 #define WARNING(d, fmt, args...) \
634 	dev_warn(&(d)->gadget->dev , fmt , ## args)
635 #define INFO(d, fmt, args...) \
636 	dev_info(&(d)->gadget->dev , fmt , ## args)
637 
638 #endif	/* __LINUX_USB_COMPOSITE_H */
639