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 #include <linux/usb/android_configfs_uevent.h>
32 
33 /*
34  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
35  * wish to delay the data/status stages of the control transfer till they
36  * are ready. The control transfer will then be kept from completing till
37  * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
38  * invoke usb_composite_setup_continue().
39  *
40  * NOTE: USB_GADGET_DELAYED_STATUS must not be used in UDC drivers: they
41  * must delay completing the status stage for 0-length control transfers
42  * regardless of the whether USB_GADGET_DELAYED_STATUS is returned from
43  * the gadget driver's setup() callback.
44  * Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS,
45  * which is a bug. These drivers must be fixed and USB_GADGET_DELAYED_STATUS
46  * must be contained within the composite framework.
47  */
48 #define USB_GADGET_DELAYED_STATUS       0x7fff	/* Impossibly large value */
49 
50 /* big enough to hold our biggest descriptor */
51 #define USB_COMP_EP0_BUFSIZ	4096
52 
53 /* OS feature descriptor length <= 4kB */
54 #define USB_COMP_EP0_OS_DESC_BUFSIZ	4096
55 
56 #define USB_MS_TO_HS_INTERVAL(x)	(ilog2((x * 1000 / 125)) + 1)
57 struct usb_configuration;
58 
59 /**
60  * struct usb_os_desc_ext_prop - describes one "Extended Property"
61  * @entry: used to keep a list of extended properties
62  * @type: Extended Property type
63  * @name_len: Extended Property unicode name length, including terminating '\0'
64  * @name: Extended Property name
65  * @data_len: Length of Extended Property blob (for unicode store double len)
66  * @data: Extended Property blob
67  * @item: Represents this Extended Property in configfs
68  */
69 struct usb_os_desc_ext_prop {
70 	struct list_head	entry;
71 	u8			type;
72 	int			name_len;
73 	char			*name;
74 	int			data_len;
75 	char			*data;
76 	struct config_item	item;
77 };
78 
79 /**
80  * struct usb_os_desc - describes OS descriptors associated with one interface
81  * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
82  * @ext_prop: Extended Properties list
83  * @ext_prop_len: Total length of Extended Properties blobs
84  * @ext_prop_count: Number of Extended Properties
85  * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
86  * @group: Represents OS descriptors associated with an interface in configfs
87  * @owner: Module associated with this OS descriptor
88  */
89 struct usb_os_desc {
90 	char			*ext_compat_id;
91 	struct list_head	ext_prop;
92 	int			ext_prop_len;
93 	int			ext_prop_count;
94 	struct mutex		*opts_mutex;
95 	struct config_group	group;
96 	struct module		*owner;
97 };
98 
99 /**
100  * struct usb_os_desc_table - describes OS descriptors associated with one
101  * interface of a usb_function
102  * @if_id: Interface id
103  * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
104  *	interface
105  *
106  * Each interface can have at most one "Extended Compatibility ID" and a
107  * number of "Extended Properties".
108  */
109 struct usb_os_desc_table {
110 	int			if_id;
111 	struct usb_os_desc	*os_desc;
112 };
113 
114 /**
115  * struct usb_function - describes one function of a configuration
116  * @name: For diagnostics, identifies the function.
117  * @strings: tables of strings, keyed by identifiers assigned during bind()
118  *	and by language IDs provided in control requests
119  * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
120  *	string identifiers assigned during @bind().  If this pointer is null,
121  *	the function will not be available at full speed (or at low speed).
122  * @hs_descriptors: Table of high speed descriptors, using interface and
123  *	string identifiers assigned during @bind().  If this pointer is null,
124  *	the function will not be available at high speed.
125  * @ss_descriptors: Table of super speed descriptors, using interface and
126  *	string identifiers assigned during @bind(). If this
127  *	pointer is null after initiation, the function will not
128  *	be available at super speed.
129  * @ssp_descriptors: Table of super speed plus descriptors, using
130  *	interface and string identifiers assigned during @bind(). If
131  *	this pointer is null after initiation, the function will not
132  *	be available at super speed plus.
133  * @config: assigned when @usb_add_function() is called; this is the
134  *	configuration with which this function is associated.
135  * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
136  *	can expose more than one interface. If an interface is a member of
137  *	an IAD, only the first interface of IAD has its entry in the table.
138  * @os_desc_n: Number of entries in os_desc_table
139  * @bind: Before the gadget can register, all of its functions bind() to the
140  *	available resources including string and interface identifiers used
141  *	in interface or class descriptors; endpoints; I/O buffers; and so on.
142  * @unbind: Reverses @bind; called as a side effect of unregistering the
143  *	driver which added this function.
144  * @free_func: free the struct usb_function.
145  * @mod: (internal) points to the module that created this structure.
146  * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
147  *	initialize usb_ep.driver data at this time (when it is used).
148  *	Note that setting an interface to its current altsetting resets
149  *	interface state, and that all interfaces have a disabled state.
150  * @get_alt: Returns the active altsetting.  If this is not provided,
151  *	then only altsetting zero is supported.
152  * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
153  *	include host resetting or reconfiguring the gadget, and disconnection.
154  * @setup: Used for interface-specific control requests.
155  * @req_match: Tests if a given class request can be handled by this function.
156  * @suspend: Notifies functions when the host stops sending USB traffic.
157  * @resume: Notifies functions when the host restarts USB traffic.
158  * @get_status: Returns function status as a reply to
159  *	GetStatus() request when the recipient is Interface.
160  * @func_suspend: callback to be called when
161  *	SetFeature(FUNCTION_SUSPEND) is reseived
162  * @func_suspended: Indicates whether the function is in function suspend state.
163  * @func_wakeup_armed: Indicates whether the function is armed by the host for
164  *	wakeup signaling.
165  *
166  * A single USB function uses one or more interfaces, and should in most
167  * cases support operation at both full and high speeds.  Each function is
168  * associated by @usb_add_function() with a one configuration; that function
169  * causes @bind() to be called so resources can be allocated as part of
170  * setting up a gadget driver.  Those resources include endpoints, which
171  * should be allocated using @usb_ep_autoconfig().
172  *
173  * To support dual speed operation, a function driver provides descriptors
174  * for both high and full speed operation.  Except in rare cases that don't
175  * involve bulk endpoints, each speed needs different endpoint descriptors.
176  *
177  * Function drivers choose their own strategies for managing instance data.
178  * The simplest strategy just declares it "static', which means the function
179  * can only be activated once.  If the function needs to be exposed in more
180  * than one configuration at a given speed, it needs to support multiple
181  * usb_function structures (one for each configuration).
182  *
183  * A more complex strategy might encapsulate a @usb_function structure inside
184  * a driver-specific instance structure to allows multiple activations.  An
185  * example of multiple activations might be a CDC ACM function that supports
186  * two or more distinct instances within the same configuration, providing
187  * several independent logical data links to a USB host.
188  */
189 
190 struct usb_function {
191 	const char			*name;
192 	struct usb_gadget_strings	**strings;
193 	struct usb_descriptor_header	**fs_descriptors;
194 	struct usb_descriptor_header	**hs_descriptors;
195 	struct usb_descriptor_header	**ss_descriptors;
196 	struct usb_descriptor_header	**ssp_descriptors;
197 
198 	struct usb_configuration	*config;
199 
200 	struct usb_os_desc_table	*os_desc_table;
201 	unsigned			os_desc_n;
202 
203 	/* REVISIT:  bind() functions can be marked __init, which
204 	 * makes trouble for section mismatch analysis.  See if
205 	 * we can't restructure things to avoid mismatching.
206 	 * Related:  unbind() may kfree() but bind() won't...
207 	 */
208 
209 	/* configuration management:  bind/unbind */
210 	int			(*bind)(struct usb_configuration *,
211 					struct usb_function *);
212 	void			(*unbind)(struct usb_configuration *,
213 					struct usb_function *);
214 	void			(*free_func)(struct usb_function *f);
215 	struct module		*mod;
216 
217 	/* runtime state management */
218 	int			(*set_alt)(struct usb_function *,
219 					unsigned interface, unsigned alt);
220 	int			(*get_alt)(struct usb_function *,
221 					unsigned interface);
222 	void			(*disable)(struct usb_function *);
223 	int			(*setup)(struct usb_function *,
224 					const struct usb_ctrlrequest *);
225 	bool			(*req_match)(struct usb_function *,
226 					const struct usb_ctrlrequest *,
227 					bool config0);
228 	void			(*suspend)(struct usb_function *);
229 	void			(*resume)(struct usb_function *);
230 
231 	/* USB 3.0 additions */
232 	int			(*get_status)(struct usb_function *);
233 	int			(*func_suspend)(struct usb_function *,
234 						u8 suspend_opt);
235 	bool			func_suspended;
236 	bool			func_wakeup_armed;
237 	/* private: */
238 	/* internals */
239 	struct list_head		list;
240 	DECLARE_BITMAP(endpoints, 32);
241 	const struct usb_function_instance *fi;
242 
243 	unsigned int		bind_deactivated:1;
244 };
245 
246 int usb_add_function(struct usb_configuration *, struct usb_function *);
247 
248 int usb_function_deactivate(struct usb_function *);
249 int usb_function_activate(struct usb_function *);
250 
251 int usb_interface_id(struct usb_configuration *, struct usb_function *);
252 
253 int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
254 				struct usb_ep *_ep, u8 alt);
255 
256 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
257 			struct usb_ep *_ep);
258 int usb_func_wakeup(struct usb_function *func);
259 
260 #define	MAX_CONFIG_INTERFACES		32
261 
262 /**
263  * struct usb_configuration - represents one gadget configuration
264  * @label: For diagnostics, describes the configuration.
265  * @strings: Tables of strings, keyed by identifiers assigned during @bind()
266  *	and by language IDs provided in control requests.
267  * @descriptors: Table of descriptors preceding all function descriptors.
268  *	Examples include OTG and vendor-specific descriptors.
269  * @unbind: Reverses @bind; called as a side effect of unregistering the
270  *	driver which added this configuration.
271  * @setup: Used to delegate control requests that aren't handled by standard
272  *	device infrastructure or directed at a specific interface.
273  * @bConfigurationValue: Copied into configuration descriptor.
274  * @iConfiguration: Copied into configuration descriptor.
275  * @bmAttributes: Copied into configuration descriptor.
276  * @MaxPower: Power consumption in mA. Used to compute bMaxPower in the
277  *	configuration descriptor after considering the bus speed.
278  * @cdev: assigned by @usb_add_config() before calling @bind(); this is
279  *	the device associated with this configuration.
280  *
281  * Configurations are building blocks for gadget drivers structured around
282  * function drivers.  Simple USB gadgets require only one function and one
283  * configuration, and handle dual-speed hardware by always providing the same
284  * functionality.  Slightly more complex gadgets may have more than one
285  * single-function configuration at a given speed; or have configurations
286  * that only work at one speed.
287  *
288  * Composite devices are, by definition, ones with configurations which
289  * include more than one function.
290  *
291  * The lifecycle of a usb_configuration includes allocation, initialization
292  * of the fields described above, and calling @usb_add_config() to set up
293  * internal data and bind it to a specific device.  The configuration's
294  * @bind() method is then used to initialize all the functions and then
295  * call @usb_add_function() for them.
296  *
297  * Those functions would normally be independent of each other, but that's
298  * not mandatory.  CDC WMC devices are an example where functions often
299  * depend on other functions, with some functions subsidiary to others.
300  * Such interdependency may be managed in any way, so long as all of the
301  * descriptors complete by the time the composite driver returns from
302  * its bind() routine.
303  */
304 struct usb_configuration {
305 	const char			*label;
306 	struct usb_gadget_strings	**strings;
307 	const struct usb_descriptor_header **descriptors;
308 
309 	/* REVISIT:  bind() functions can be marked __init, which
310 	 * makes trouble for section mismatch analysis.  See if
311 	 * we can't restructure things to avoid mismatching...
312 	 */
313 
314 	/* configuration management: unbind/setup */
315 	void			(*unbind)(struct usb_configuration *);
316 	int			(*setup)(struct usb_configuration *,
317 					const struct usb_ctrlrequest *);
318 
319 	/* fields in the config descriptor */
320 	u8			bConfigurationValue;
321 	u8			iConfiguration;
322 	u8			bmAttributes;
323 	u16			MaxPower;
324 
325 	struct usb_composite_dev	*cdev;
326 
327 	/* private: */
328 	/* internals */
329 	struct list_head	list;
330 	struct list_head	functions;
331 	u8			next_interface_id;
332 	unsigned		superspeed:1;
333 	unsigned		highspeed:1;
334 	unsigned		fullspeed:1;
335 	unsigned		superspeed_plus:1;
336 	struct usb_function	*interface[MAX_CONFIG_INTERFACES];
337 };
338 
339 int usb_add_config(struct usb_composite_dev *,
340 		struct usb_configuration *,
341 		int (*)(struct usb_configuration *));
342 
343 void usb_remove_config(struct usb_composite_dev *,
344 		struct usb_configuration *);
345 
346 /* predefined index for usb_composite_driver */
347 enum {
348 	USB_GADGET_MANUFACTURER_IDX	= 0,
349 	USB_GADGET_PRODUCT_IDX,
350 	USB_GADGET_SERIAL_IDX,
351 	USB_GADGET_FIRST_AVAIL_IDX,
352 };
353 
354 /**
355  * struct usb_composite_driver - groups configurations into a gadget
356  * @name: For diagnostics, identifies the driver.
357  * @dev: Template descriptor for the device, including default device
358  *	identifiers.
359  * @strings: tables of strings, keyed by identifiers assigned during @bind
360  *	and language IDs provided in control requests. Note: The first entries
361  *	are predefined. The first entry that may be used is
362  *	USB_GADGET_FIRST_AVAIL_IDX
363  * @max_speed: Highest speed the driver supports.
364  * @needs_serial: set to 1 if the gadget needs userspace to provide
365  * 	a serial number.  If one is not provided, warning will be printed.
366  * @bind: (REQUIRED) Used to allocate resources that are shared across the
367  *	whole device, such as string IDs, and add its configurations using
368  *	@usb_add_config(). This may fail by returning a negative errno
369  *	value; it should return zero on successful initialization.
370  * @unbind: Reverses @bind; called as a side effect of unregistering
371  *	this driver.
372  * @disconnect: optional driver disconnect method
373  * @suspend: Notifies when the host stops sending USB traffic,
374  *	after function notifications
375  * @resume: Notifies configuration when the host restarts USB traffic,
376  *	before function notifications
377  * @gadget_driver: Gadget driver controlling this driver
378  *
379  * Devices default to reporting self powered operation.  Devices which rely
380  * on bus powered operation should report this in their @bind method.
381  *
382  * Before returning from @bind, various fields in the template descriptor
383  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
384  * normally to bind the appropriate host side driver, and the three strings
385  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
386  * meaningful device identifiers.  (The strings will not be defined unless
387  * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
388  * is also reported, as defined by the underlying controller driver.
389  */
390 struct usb_composite_driver {
391 	const char				*name;
392 	const struct usb_device_descriptor	*dev;
393 	struct usb_gadget_strings		**strings;
394 	enum usb_device_speed			max_speed;
395 	unsigned		needs_serial:1;
396 
397 	int			(*bind)(struct usb_composite_dev *cdev);
398 	int			(*unbind)(struct usb_composite_dev *);
399 
400 	void			(*disconnect)(struct usb_composite_dev *);
401 
402 	/* global suspend hooks */
403 	void			(*suspend)(struct usb_composite_dev *);
404 	void			(*resume)(struct usb_composite_dev *);
405 	struct usb_gadget_driver		gadget_driver;
406 };
407 
408 extern int usb_composite_probe(struct usb_composite_driver *driver);
409 extern void usb_composite_unregister(struct usb_composite_driver *driver);
410 
411 /**
412  * module_usb_composite_driver() - Helper macro for registering a USB gadget
413  * composite driver
414  * @__usb_composite_driver: usb_composite_driver struct
415  *
416  * Helper macro for USB gadget composite drivers which do not do anything
417  * special in module init/exit. This eliminates a lot of boilerplate. Each
418  * module may only use this macro once, and calling it replaces module_init()
419  * and module_exit()
420  */
421 #define module_usb_composite_driver(__usb_composite_driver) \
422 	module_driver(__usb_composite_driver, usb_composite_probe, \
423 		       usb_composite_unregister)
424 
425 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
426 extern int composite_dev_prepare(struct usb_composite_driver *composite,
427 		struct usb_composite_dev *cdev);
428 extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
429 					 struct usb_ep *ep0);
430 void composite_dev_cleanup(struct usb_composite_dev *cdev);
431 void check_remote_wakeup_config(struct usb_gadget *g,
432 				struct usb_configuration *c);
433 
to_cdriver(struct usb_gadget_driver * gdrv)434 static inline struct usb_composite_driver *to_cdriver(
435 		struct usb_gadget_driver *gdrv)
436 {
437 	return container_of(gdrv, struct usb_composite_driver, gadget_driver);
438 }
439 
440 #define OS_STRING_QW_SIGN_LEN		14
441 #define OS_STRING_IDX			0xEE
442 
443 /**
444  * struct usb_composite_dev - represents one composite usb gadget
445  * @gadget: read-only, abstracts the gadget's usb peripheral controller
446  * @req: used for control responses; buffer is pre-allocated
447  * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
448  * @config: the currently active configuration
449  * @qw_sign: qwSignature part of the OS string
450  * @b_vendor_code: bMS_VendorCode part of the OS string
451  * @use_os_string: false by default, interested gadgets set it
452  * @bcd_webusb_version: 0x0100 by default, WebUSB specification version
453  * @b_webusb_vendor_code: 0x0 by default, vendor code for WebUSB
454  * @landing_page: empty by default, landing page to announce in WebUSB
455  * @use_webusb: false by default, interested gadgets set it
456  * @os_desc_config: the configuration to be used with OS descriptors
457  * @setup_pending: true when setup request is queued but not completed
458  * @os_desc_pending: true when os_desc request is queued but not completed
459  *
460  * One of these devices is allocated and initialized before the
461  * associated device driver's bind() is called.
462  */
463 struct usb_composite_dev {
464 	struct usb_gadget		*gadget;
465 	struct usb_request		*req;
466 	struct usb_request		*os_desc_req;
467 
468 	struct usb_configuration	*config;
469 
470 	/* OS String is a custom (yet popular) extension to the USB standard. */
471 	u8				qw_sign[OS_STRING_QW_SIGN_LEN];
472 	u8				b_vendor_code;
473 	struct usb_configuration	*os_desc_config;
474 	unsigned int			use_os_string:1;
475 
476 	/* WebUSB */
477 	u16				bcd_webusb_version;
478 	u8				b_webusb_vendor_code;
479 	char				landing_page[WEBUSB_URL_RAW_MAX_LENGTH];
480 	unsigned int			use_webusb:1;
481 
482 	/* private: */
483 	/* internals */
484 	unsigned int			suspended:1;
485 	struct usb_device_descriptor	desc;
486 	struct list_head		configs;
487 	struct list_head		gstrings;
488 	struct usb_composite_driver	*driver;
489 	u8				next_string_id;
490 	char				*def_manufacturer;
491 	struct usb_string		*usb_strings;
492 
493 	/* the gadget driver won't enable the data pullup
494 	 * while the deactivation count is nonzero.
495 	 */
496 	unsigned			deactivations;
497 
498 	/* the composite driver won't complete the control transfer's
499 	 * data/status stages till delayed_status is zero.
500 	 */
501 	int				delayed_status;
502 
503 	/* protects deactivations and delayed_status counts*/
504 	spinlock_t			lock;
505 
506 	struct android_uevent_opts	android_opts;
507 
508 	/* public: */
509 	unsigned int			setup_pending:1;
510 	unsigned int			os_desc_pending:1;
511 };
512 
513 extern int usb_string_id(struct usb_composite_dev *c);
514 extern int usb_string_ids_tab(struct usb_composite_dev *c,
515 			      struct usb_string *str);
516 extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
517 		struct usb_gadget_strings **sp, unsigned n_strings);
518 
519 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
520 
521 extern void composite_disconnect(struct usb_gadget *gadget);
522 extern void composite_reset(struct usb_gadget *gadget);
523 
524 extern int composite_setup(struct usb_gadget *gadget,
525 		const struct usb_ctrlrequest *ctrl);
526 extern void composite_suspend(struct usb_gadget *gadget);
527 extern void composite_resume(struct usb_gadget *gadget);
528 
529 /*
530  * Some systems will need runtime overrides for the  product identifiers
531  * published in the device descriptor, either numbers or strings or both.
532  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
533  */
534 struct usb_composite_overwrite {
535 	u16	idVendor;
536 	u16	idProduct;
537 	u16	bcdDevice;
538 	char	*serial_number;
539 	char	*manufacturer;
540 	char	*product;
541 };
542 #define USB_GADGET_COMPOSITE_OPTIONS()					\
543 	static struct usb_composite_overwrite coverwrite;		\
544 									\
545 	module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
546 	MODULE_PARM_DESC(idVendor, "USB Vendor ID");			\
547 									\
548 	module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
549 	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
550 									\
551 	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
552 	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
553 									\
554 	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
555 			S_IRUGO); \
556 	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");		\
557 									\
558 	module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
559 			S_IRUGO); \
560 	MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");	\
561 									\
562 	module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
563 	MODULE_PARM_DESC(iProduct, "USB Product string")
564 
565 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
566 		struct usb_composite_overwrite *covr);
567 
get_default_bcdDevice(void)568 static inline u16 get_default_bcdDevice(void)
569 {
570 	u16 bcdDevice;
571 
572 	bcdDevice = bin2bcd(LINUX_VERSION_MAJOR) << 8;
573 	bcdDevice |= bin2bcd(LINUX_VERSION_PATCHLEVEL);
574 	return bcdDevice;
575 }
576 
577 struct usb_function_driver {
578 	const char *name;
579 	struct module *mod;
580 	struct list_head list;
581 	struct usb_function_instance *(*alloc_inst)(void);
582 	struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
583 };
584 
585 struct usb_function_instance {
586 	struct config_group group;
587 	struct list_head cfs_list;
588 	struct usb_function_driver *fd;
589 	int (*set_inst_name)(struct usb_function_instance *inst,
590 			      const char *name);
591 	void (*free_func_inst)(struct usb_function_instance *inst);
592 };
593 
594 void usb_function_unregister(struct usb_function_driver *f);
595 int usb_function_register(struct usb_function_driver *newf);
596 void usb_put_function_instance(struct usb_function_instance *fi);
597 void usb_put_function(struct usb_function *f);
598 struct usb_function_instance *usb_get_function_instance(const char *name);
599 struct usb_function *usb_get_function(struct usb_function_instance *fi);
600 
601 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
602 		int val);
603 int usb_add_config_only(struct usb_composite_dev *cdev,
604 		struct usb_configuration *config);
605 void usb_remove_function(struct usb_configuration *c, struct usb_function *f);
606 
607 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
608 	static struct usb_function_driver _name ## usb_func = {		\
609 		.name = __stringify(_name),				\
610 		.mod  = THIS_MODULE,					\
611 		.alloc_inst = _inst_alloc,				\
612 		.alloc_func = _func_alloc,				\
613 	};								\
614 	MODULE_ALIAS("usbfunc:"__stringify(_name));
615 
616 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc)	\
617 	DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
618 	static int __init _name ## mod_init(void)			\
619 	{								\
620 		return usb_function_register(&_name ## usb_func);	\
621 	}								\
622 	static void __exit _name ## mod_exit(void)			\
623 	{								\
624 		usb_function_unregister(&_name ## usb_func);		\
625 	}								\
626 	module_init(_name ## mod_init);					\
627 	module_exit(_name ## mod_exit)
628 
629 /* messaging utils */
630 #define DBG(d, fmt, args...) \
631 	dev_dbg(&(d)->gadget->dev , fmt , ## args)
632 #define VDBG(d, fmt, args...) \
633 	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
634 #define ERROR(d, fmt, args...) \
635 	dev_err(&(d)->gadget->dev , fmt , ## args)
636 #define WARNING(d, fmt, args...) \
637 	dev_warn(&(d)->gadget->dev , fmt , ## args)
638 #define INFO(d, fmt, args...) \
639 	dev_info(&(d)->gadget->dev , fmt , ## args)
640 
641 #endif	/* __LINUX_USB_COMPOSITE_H */
642