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  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
20  */
21 
22 #ifndef	__LINUX_USB_COMPOSITE_H
23 #define	__LINUX_USB_COMPOSITE_H
24 
25 /*
26  * This framework is an optional layer on top of the USB Gadget interface,
27  * making it easier to build (a) Composite devices, supporting multiple
28  * functions within any single configuration, and (b) Multi-configuration
29  * devices, also supporting multiple functions but without necessarily
30  * having more than one function per configuration.
31  *
32  * Example:  a device with a single configuration supporting both network
33  * link and mass storage functions is a composite device.  Those functions
34  * might alternatively be packaged in individual configurations, but in
35  * the composite model the host can use both functions at the same time.
36  */
37 
38 #include <linux/bcd.h>
39 #include <linux/version.h>
40 #include <linux/usb/ch9.h>
41 #include <linux/usb/gadget.h>
42 #include <linux/log2.h>
43 #include <linux/configfs.h>
44 
45 /*
46  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
47  * wish to delay the data/status stages of the control transfer till they
48  * are ready. The control transfer will then be kept from completing till
49  * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
50  * invoke usb_composite_setup_continue().
51  */
52 #define USB_GADGET_DELAYED_STATUS       0x7fff	/* Impossibly large value */
53 
54 /* big enough to hold our biggest descriptor */
55 #define USB_COMP_EP0_BUFSIZ	4096
56 
57 /* OS feature descriptor length <= 4kB */
58 #define USB_COMP_EP0_OS_DESC_BUFSIZ	4096
59 
60 #define USB_MS_TO_HS_INTERVAL(x)	(ilog2((x * 1000 / 125)) + 1)
61 struct usb_configuration;
62 
63 /**
64  * struct usb_os_desc_ext_prop - describes one "Extended Property"
65  * @entry: used to keep a list of extended properties
66  * @type: Extended Property type
67  * @name_len: Extended Property unicode name length, including terminating '\0'
68  * @name: Extended Property name
69  * @data_len: Length of Extended Property blob (for unicode store double len)
70  * @data: Extended Property blob
71  * @item: Represents this Extended Property in configfs
72  */
73 struct usb_os_desc_ext_prop {
74 	struct list_head	entry;
75 	u8			type;
76 	int			name_len;
77 	char			*name;
78 	int			data_len;
79 	char			*data;
80 	struct config_item	item;
81 };
82 
83 /**
84  * struct usb_os_desc - describes OS descriptors associated with one interface
85  * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
86  * @ext_prop: Extended Properties list
87  * @ext_prop_len: Total length of Extended Properties blobs
88  * @ext_prop_count: Number of Extended Properties
89  * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
90  * @group: Represents OS descriptors associated with an interface in configfs
91  * @owner: Module associated with this OS descriptor
92  */
93 struct usb_os_desc {
94 	char			*ext_compat_id;
95 	struct list_head	ext_prop;
96 	int			ext_prop_len;
97 	int			ext_prop_count;
98 	struct mutex		*opts_mutex;
99 	struct config_group	group;
100 	struct module		*owner;
101 };
102 
103 /**
104  * struct usb_os_desc_table - describes OS descriptors associated with one
105  * interface of a usb_function
106  * @if_id: Interface id
107  * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
108  *	interface
109  *
110  * Each interface can have at most one "Extended Compatibility ID" and a
111  * number of "Extended Properties".
112  */
113 struct usb_os_desc_table {
114 	int			if_id;
115 	struct usb_os_desc	*os_desc;
116 };
117 
118 /**
119  * struct usb_function - describes one function of a configuration
120  * @name: For diagnostics, identifies the function.
121  * @strings: tables of strings, keyed by identifiers assigned during bind()
122  *	and by language IDs provided in control requests
123  * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
124  *	string identifiers assigned during @bind().  If this pointer is null,
125  *	the function will not be available at full speed (or at low speed).
126  * @hs_descriptors: Table of high speed descriptors, using interface and
127  *	string identifiers assigned during @bind().  If this pointer is null,
128  *	the function will not be available at high speed.
129  * @ss_descriptors: Table of super speed descriptors, using interface and
130  *	string identifiers assigned during @bind(). If this
131  *	pointer is null after initiation, the function will not
132  *	be available at super speed.
133  * @ssp_descriptors: Table of super speed plus descriptors, using
134  *	interface and string identifiers assigned during @bind(). If
135  *	this pointer is null after initiation, the function will not
136  *	be available at super speed plus.
137  * @config: assigned when @usb_add_function() is called; this is the
138  *	configuration with which this function is associated.
139  * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
140  *	can expose more than one interface. If an interface is a member of
141  *	an IAD, only the first interface of IAD has its entry in the table.
142  * @os_desc_n: Number of entries in os_desc_table
143  * @bind: Before the gadget can register, all of its functions bind() to the
144  *	available resources including string and interface identifiers used
145  *	in interface or class descriptors; endpoints; I/O buffers; and so on.
146  * @unbind: Reverses @bind; called as a side effect of unregistering the
147  *	driver which added this function.
148  * @free_func: free the struct usb_function.
149  * @mod: (internal) points to the module that created this structure.
150  * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
151  *	initialize usb_ep.driver data at this time (when it is used).
152  *	Note that setting an interface to its current altsetting resets
153  *	interface state, and that all interfaces have a disabled state.
154  * @get_alt: Returns the active altsetting.  If this is not provided,
155  *	then only altsetting zero is supported.
156  * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
157  *	include host resetting or reconfiguring the gadget, and disconnection.
158  * @setup: Used for interface-specific control requests.
159  * @req_match: Tests if a given class request can be handled by this function.
160  * @suspend: Notifies functions when the host stops sending USB traffic.
161  * @resume: Notifies functions when the host restarts USB traffic.
162  * @get_status: Returns function status as a reply to
163  *	GetStatus() request when the recipient is Interface.
164  * @func_suspend: callback to be called when
165  *	SetFeature(FUNCTION_SUSPEND) is reseived
166  *
167  * A single USB function uses one or more interfaces, and should in most
168  * cases support operation at both full and high speeds.  Each function is
169  * associated by @usb_add_function() with a one configuration; that function
170  * causes @bind() to be called so resources can be allocated as part of
171  * setting up a gadget driver.  Those resources include endpoints, which
172  * should be allocated using @usb_ep_autoconfig().
173  *
174  * To support dual speed operation, a function driver provides descriptors
175  * for both high and full speed operation.  Except in rare cases that don't
176  * involve bulk endpoints, each speed needs different endpoint descriptors.
177  *
178  * Function drivers choose their own strategies for managing instance data.
179  * The simplest strategy just declares it "static', which means the function
180  * can only be activated once.  If the function needs to be exposed in more
181  * than one configuration at a given speed, it needs to support multiple
182  * usb_function structures (one for each configuration).
183  *
184  * A more complex strategy might encapsulate a @usb_function structure inside
185  * a driver-specific instance structure to allows multiple activations.  An
186  * example of multiple activations might be a CDC ACM function that supports
187  * two or more distinct instances within the same configuration, providing
188  * several independent logical data links to a USB host.
189  */
190 
191 struct usb_function {
192 	const char			*name;
193 	struct usb_gadget_strings	**strings;
194 	struct usb_descriptor_header	**fs_descriptors;
195 	struct usb_descriptor_header	**hs_descriptors;
196 	struct usb_descriptor_header	**ss_descriptors;
197 	struct usb_descriptor_header	**ssp_descriptors;
198 
199 	struct usb_configuration	*config;
200 
201 	struct usb_os_desc_table	*os_desc_table;
202 	unsigned			os_desc_n;
203 
204 	/* REVISIT:  bind() functions can be marked __init, which
205 	 * makes trouble for section mismatch analysis.  See if
206 	 * we can't restructure things to avoid mismatching.
207 	 * Related:  unbind() may kfree() but bind() won't...
208 	 */
209 
210 	/* configuration management:  bind/unbind */
211 	int			(*bind)(struct usb_configuration *,
212 					struct usb_function *);
213 	void			(*unbind)(struct usb_configuration *,
214 					struct usb_function *);
215 	void			(*free_func)(struct usb_function *f);
216 	struct module		*mod;
217 
218 	/* runtime state management */
219 	int			(*set_alt)(struct usb_function *,
220 					unsigned interface, unsigned alt);
221 	int			(*get_alt)(struct usb_function *,
222 					unsigned interface);
223 	void			(*disable)(struct usb_function *);
224 	int			(*setup)(struct usb_function *,
225 					const struct usb_ctrlrequest *);
226 	bool			(*req_match)(struct usb_function *,
227 					const struct usb_ctrlrequest *,
228 					bool config0);
229 	void			(*suspend)(struct usb_function *);
230 	void			(*resume)(struct usb_function *);
231 
232 	/* USB 3.0 additions */
233 	int			(*get_status)(struct usb_function *);
234 	int			(*func_suspend)(struct usb_function *,
235 						u8 suspend_opt);
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 
258 #define	MAX_CONFIG_INTERFACES		16	/* arbitrary; max 255 */
259 
260 /**
261  * struct usb_configuration - represents one gadget configuration
262  * @label: For diagnostics, describes the configuration.
263  * @strings: Tables of strings, keyed by identifiers assigned during @bind()
264  *	and by language IDs provided in control requests.
265  * @descriptors: Table of descriptors preceding all function descriptors.
266  *	Examples include OTG and vendor-specific descriptors.
267  * @unbind: Reverses @bind; called as a side effect of unregistering the
268  *	driver which added this configuration.
269  * @setup: Used to delegate control requests that aren't handled by standard
270  *	device infrastructure or directed at a specific interface.
271  * @bConfigurationValue: Copied into configuration descriptor.
272  * @iConfiguration: Copied into configuration descriptor.
273  * @bmAttributes: Copied into configuration descriptor.
274  * @MaxPower: Power consumption in mA. Used to compute bMaxPower in the
275  *	configuration descriptor after considering the bus speed.
276  * @cdev: assigned by @usb_add_config() before calling @bind(); this is
277  *	the device associated with this configuration.
278  *
279  * Configurations are building blocks for gadget drivers structured around
280  * function drivers.  Simple USB gadgets require only one function and one
281  * configuration, and handle dual-speed hardware by always providing the same
282  * functionality.  Slightly more complex gadgets may have more than one
283  * single-function configuration at a given speed; or have configurations
284  * that only work at one speed.
285  *
286  * Composite devices are, by definition, ones with configurations which
287  * include more than one function.
288  *
289  * The lifecycle of a usb_configuration includes allocation, initialization
290  * of the fields described above, and calling @usb_add_config() to set up
291  * internal data and bind it to a specific device.  The configuration's
292  * @bind() method is then used to initialize all the functions and then
293  * call @usb_add_function() for them.
294  *
295  * Those functions would normally be independent of each other, but that's
296  * not mandatory.  CDC WMC devices are an example where functions often
297  * depend on other functions, with some functions subsidiary to others.
298  * Such interdependency may be managed in any way, so long as all of the
299  * descriptors complete by the time the composite driver returns from
300  * its bind() routine.
301  */
302 struct usb_configuration {
303 	const char			*label;
304 	struct usb_gadget_strings	**strings;
305 	const struct usb_descriptor_header **descriptors;
306 
307 	/* REVISIT:  bind() functions can be marked __init, which
308 	 * makes trouble for section mismatch analysis.  See if
309 	 * we can't restructure things to avoid mismatching...
310 	 */
311 
312 	/* configuration management: unbind/setup */
313 	void			(*unbind)(struct usb_configuration *);
314 	int			(*setup)(struct usb_configuration *,
315 					const struct usb_ctrlrequest *);
316 
317 	/* fields in the config descriptor */
318 	u8			bConfigurationValue;
319 	u8			iConfiguration;
320 	u8			bmAttributes;
321 	u16			MaxPower;
322 
323 	struct usb_composite_dev	*cdev;
324 
325 	/* private: */
326 	/* internals */
327 	struct list_head	list;
328 	struct list_head	functions;
329 	u8			next_interface_id;
330 	unsigned		superspeed:1;
331 	unsigned		highspeed:1;
332 	unsigned		fullspeed:1;
333 	unsigned		superspeed_plus:1;
334 	struct usb_function	*interface[MAX_CONFIG_INTERFACES];
335 };
336 
337 int usb_add_config(struct usb_composite_dev *,
338 		struct usb_configuration *,
339 		int (*)(struct usb_configuration *));
340 
341 void usb_remove_config(struct usb_composite_dev *,
342 		struct usb_configuration *);
343 
344 /* predefined index for usb_composite_driver */
345 enum {
346 	USB_GADGET_MANUFACTURER_IDX	= 0,
347 	USB_GADGET_PRODUCT_IDX,
348 	USB_GADGET_SERIAL_IDX,
349 	USB_GADGET_FIRST_AVAIL_IDX,
350 };
351 
352 /**
353  * struct usb_composite_driver - groups configurations into a gadget
354  * @name: For diagnostics, identifies the driver.
355  * @dev: Template descriptor for the device, including default device
356  *	identifiers.
357  * @strings: tables of strings, keyed by identifiers assigned during @bind
358  *	and language IDs provided in control requests. Note: The first entries
359  *	are predefined. The first entry that may be used is
360  *	USB_GADGET_FIRST_AVAIL_IDX
361  * @max_speed: Highest speed the driver supports.
362  * @needs_serial: set to 1 if the gadget needs userspace to provide
363  * 	a serial number.  If one is not provided, warning will be printed.
364  * @bind: (REQUIRED) Used to allocate resources that are shared across the
365  *	whole device, such as string IDs, and add its configurations using
366  *	@usb_add_config(). This may fail by returning a negative errno
367  *	value; it should return zero on successful initialization.
368  * @unbind: Reverses @bind; called as a side effect of unregistering
369  *	this driver.
370  * @disconnect: optional driver disconnect method
371  * @suspend: Notifies when the host stops sending USB traffic,
372  *	after function notifications
373  * @resume: Notifies configuration when the host restarts USB traffic,
374  *	before function notifications
375  * @gadget_driver: Gadget driver controlling this driver
376  *
377  * Devices default to reporting self powered operation.  Devices which rely
378  * on bus powered operation should report this in their @bind method.
379  *
380  * Before returning from @bind, various fields in the template descriptor
381  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
382  * normally to bind the appropriate host side driver, and the three strings
383  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
384  * meaningful device identifiers.  (The strings will not be defined unless
385  * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
386  * is also reported, as defined by the underlying controller driver.
387  */
388 struct usb_composite_driver {
389 	const char				*name;
390 	const struct usb_device_descriptor	*dev;
391 	struct usb_gadget_strings		**strings;
392 	enum usb_device_speed			max_speed;
393 	unsigned		needs_serial:1;
394 
395 	int			(*bind)(struct usb_composite_dev *cdev);
396 	int			(*unbind)(struct usb_composite_dev *);
397 
398 	void			(*disconnect)(struct usb_composite_dev *);
399 
400 	/* global suspend hooks */
401 	void			(*suspend)(struct usb_composite_dev *);
402 	void			(*resume)(struct usb_composite_dev *);
403 	struct usb_gadget_driver		gadget_driver;
404 };
405 
406 extern int usb_composite_probe(struct usb_composite_driver *driver);
407 extern void usb_composite_unregister(struct usb_composite_driver *driver);
408 
409 /**
410  * module_usb_composite_driver() - Helper macro for registering a USB gadget
411  * composite driver
412  * @__usb_composite_driver: usb_composite_driver struct
413  *
414  * Helper macro for USB gadget composite drivers which do not do anything
415  * special in module init/exit. This eliminates a lot of boilerplate. Each
416  * module may only use this macro once, and calling it replaces module_init()
417  * and module_exit()
418  */
419 #define module_usb_composite_driver(__usb_composite_driver) \
420 	module_driver(__usb_composite_driver, usb_composite_probe, \
421 		       usb_composite_unregister)
422 
423 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
424 extern int composite_dev_prepare(struct usb_composite_driver *composite,
425 		struct usb_composite_dev *cdev);
426 extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
427 					 struct usb_ep *ep0);
428 void composite_dev_cleanup(struct usb_composite_dev *cdev);
429 
to_cdriver(struct usb_gadget_driver * gdrv)430 static inline struct usb_composite_driver *to_cdriver(
431 		struct usb_gadget_driver *gdrv)
432 {
433 	return container_of(gdrv, struct usb_composite_driver, gadget_driver);
434 }
435 
436 #define OS_STRING_QW_SIGN_LEN		14
437 #define OS_STRING_IDX			0xEE
438 
439 /**
440  * struct usb_composite_dev - represents one composite usb gadget
441  * @gadget: read-only, abstracts the gadget's usb peripheral controller
442  * @req: used for control responses; buffer is pre-allocated
443  * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
444  * @config: the currently active configuration
445  * @qw_sign: qwSignature part of the OS string
446  * @b_vendor_code: bMS_VendorCode part of the OS string
447  * @use_os_string: false by default, interested gadgets set it
448  * @os_desc_config: the configuration to be used with OS descriptors
449  * @setup_pending: true when setup request is queued but not completed
450  * @os_desc_pending: true when os_desc request is queued but not completed
451  *
452  * One of these devices is allocated and initialized before the
453  * associated device driver's bind() is called.
454  *
455  * OPEN ISSUE:  it appears that some WUSB devices will need to be
456  * built by combining a normal (wired) gadget with a wireless one.
457  * This revision of the gadget framework should probably try to make
458  * sure doing that won't hurt too much.
459  *
460  * One notion for how to handle Wireless USB devices involves:
461  *
462  * (a) a second gadget here, discovery mechanism TBD, but likely
463  *     needing separate "register/unregister WUSB gadget" calls;
464  * (b) updates to usb_gadget to include flags "is it wireless",
465  *     "is it wired", plus (presumably in a wrapper structure)
466  *     bandgroup and PHY info;
467  * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
468  *     wireless-specific parameters like maxburst and maxsequence;
469  * (d) configurations that are specific to wireless links;
470  * (e) function drivers that understand wireless configs and will
471  *     support wireless for (additional) function instances;
472  * (f) a function to support association setup (like CBAF), not
473  *     necessarily requiring a wireless adapter;
474  * (g) composite device setup that can create one or more wireless
475  *     configs, including appropriate association setup support;
476  * (h) more, TBD.
477  */
478 struct usb_composite_dev {
479 	struct usb_gadget		*gadget;
480 	struct usb_request		*req;
481 	struct usb_request		*os_desc_req;
482 
483 	struct usb_configuration	*config;
484 
485 	/* OS String is a custom (yet popular) extension to the USB standard. */
486 	u8				qw_sign[OS_STRING_QW_SIGN_LEN];
487 	u8				b_vendor_code;
488 	struct usb_configuration	*os_desc_config;
489 	unsigned int			use_os_string:1;
490 
491 	/* private: */
492 	/* internals */
493 	unsigned int			suspended:1;
494 	struct usb_device_descriptor	desc;
495 	struct list_head		configs;
496 	struct list_head		gstrings;
497 	struct usb_composite_driver	*driver;
498 	u8				next_string_id;
499 	char				*def_manufacturer;
500 
501 	/* the gadget driver won't enable the data pullup
502 	 * while the deactivation count is nonzero.
503 	 */
504 	unsigned			deactivations;
505 
506 	/* the composite driver won't complete the control transfer's
507 	 * data/status stages till delayed_status is zero.
508 	 */
509 	int				delayed_status;
510 
511 	/* protects deactivations and delayed_status counts*/
512 	spinlock_t			lock;
513 
514 	/* public: */
515 	unsigned int			setup_pending:1;
516 	unsigned int			os_desc_pending:1;
517 };
518 
519 extern int usb_string_id(struct usb_composite_dev *c);
520 extern int usb_string_ids_tab(struct usb_composite_dev *c,
521 			      struct usb_string *str);
522 extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
523 		struct usb_gadget_strings **sp, unsigned n_strings);
524 
525 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
526 
527 extern void composite_disconnect(struct usb_gadget *gadget);
528 extern void composite_reset(struct usb_gadget *gadget);
529 
530 extern int composite_setup(struct usb_gadget *gadget,
531 		const struct usb_ctrlrequest *ctrl);
532 extern void composite_suspend(struct usb_gadget *gadget);
533 extern void composite_resume(struct usb_gadget *gadget);
534 
535 /*
536  * Some systems will need runtime overrides for the  product identifiers
537  * published in the device descriptor, either numbers or strings or both.
538  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
539  */
540 struct usb_composite_overwrite {
541 	u16	idVendor;
542 	u16	idProduct;
543 	u16	bcdDevice;
544 	char	*serial_number;
545 	char	*manufacturer;
546 	char	*product;
547 };
548 #define USB_GADGET_COMPOSITE_OPTIONS()					\
549 	static struct usb_composite_overwrite coverwrite;		\
550 									\
551 	module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
552 	MODULE_PARM_DESC(idVendor, "USB Vendor ID");			\
553 									\
554 	module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
555 	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
556 									\
557 	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
558 	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
559 									\
560 	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
561 			S_IRUGO); \
562 	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");		\
563 									\
564 	module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
565 			S_IRUGO); \
566 	MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");	\
567 									\
568 	module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
569 	MODULE_PARM_DESC(iProduct, "USB Product string")
570 
571 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
572 		struct usb_composite_overwrite *covr);
573 
get_default_bcdDevice(void)574 static inline u16 get_default_bcdDevice(void)
575 {
576 	u16 bcdDevice;
577 
578 	bcdDevice = bin2bcd(LINUX_VERSION_MAJOR) << 8;
579 	bcdDevice |= bin2bcd(LINUX_VERSION_PATCHLEVEL);
580 	return bcdDevice;
581 }
582 
583 struct usb_function_driver {
584 	const char *name;
585 	struct module *mod;
586 	struct list_head list;
587 	struct usb_function_instance *(*alloc_inst)(void);
588 	struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
589 };
590 
591 struct usb_function_instance {
592 	struct config_group group;
593 	struct list_head cfs_list;
594 	struct usb_function_driver *fd;
595 	int (*set_inst_name)(struct usb_function_instance *inst,
596 			      const char *name);
597 	void (*free_func_inst)(struct usb_function_instance *inst);
598 };
599 
600 void usb_function_unregister(struct usb_function_driver *f);
601 int usb_function_register(struct usb_function_driver *newf);
602 void usb_put_function_instance(struct usb_function_instance *fi);
603 void usb_put_function(struct usb_function *f);
604 struct usb_function_instance *usb_get_function_instance(const char *name);
605 struct usb_function *usb_get_function(struct usb_function_instance *fi);
606 
607 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
608 		int val);
609 int usb_add_config_only(struct usb_composite_dev *cdev,
610 		struct usb_configuration *config);
611 void usb_remove_function(struct usb_configuration *c, struct usb_function *f);
612 
613 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
614 	static struct usb_function_driver _name ## usb_func = {		\
615 		.name = __stringify(_name),				\
616 		.mod  = THIS_MODULE,					\
617 		.alloc_inst = _inst_alloc,				\
618 		.alloc_func = _func_alloc,				\
619 	};								\
620 	MODULE_ALIAS("usbfunc:"__stringify(_name));
621 
622 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc)	\
623 	DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)		\
624 	static int __init _name ## mod_init(void)			\
625 	{								\
626 		return usb_function_register(&_name ## usb_func);	\
627 	}								\
628 	static void __exit _name ## mod_exit(void)			\
629 	{								\
630 		usb_function_unregister(&_name ## usb_func);		\
631 	}								\
632 	module_init(_name ## mod_init);					\
633 	module_exit(_name ## mod_exit)
634 
635 /* messaging utils */
636 #define DBG(d, fmt, args...) \
637 	dev_dbg(&(d)->gadget->dev , fmt , ## args)
638 #define VDBG(d, fmt, args...) \
639 	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
640 #define ERROR(d, fmt, args...) \
641 	dev_err(&(d)->gadget->dev , fmt , ## args)
642 #define WARNING(d, fmt, args...) \
643 	dev_warn(&(d)->gadget->dev , fmt , ## args)
644 #define INFO(d, fmt, args...) \
645 	dev_info(&(d)->gadget->dev , fmt , ## args)
646 
647 #endif	/* __LINUX_USB_COMPOSITE_H */
648