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