include/linux/usb/composite.h

   1 /*
   2  * composite.h -- framework for usb gadgets which are composite devices
   3  *
   4  * Copyright (C) 2006-2008 David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #ifndef __LINUX_USB_COMPOSITE_H
  22 #define __LINUX_USB_COMPOSITE_H
  23
  24 /*
  25  * This framework is an optional layer on top of the USB Gadget interface,
  26  * making it easier to build (a) Composite devices, supporting multiple
  27  * functions within any single configuration, and (b) Multi-configuration
  28  * devices, also supporting multiple functions but without necessarily
  29  * having more than one function per configuration.
  30  *
  31  * Example:  a device with a single configuration supporting both network
  32  * link and mass storage functions is a composite device.  Those functions
  33  * might alternatively be packaged in individual configurations, but in
  34  * the composite model the host can use both functions at the same time.
  35  */
  36
  37 #include <linux/bcd.h>
  38 #include <linux/version.h>
  39 #include <linux/usb/ch9.h>
  40 #include <linux/usb/gadget.h>
  41 #include <linux/log2.h>
  42 #include <linux/configfs.h>
  43
  44 /*
  45  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
  46  * wish to delay the data/status stages of the control transfer till they
  47  * are ready. The control transfer will then be kept from completing till
  48  * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
  49  * invoke usb_composite_setup_continue().
  50  */
  51 #define USB_GADGET_DELAYED_STATUS       0x7fff  /* Impossibly large value */
  52
  53 /* big enough to hold our biggest descriptor */
  54 #define USB_COMP_EP0_BUFSIZ     1024
  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  * @config: assigned when @usb_add_function() is called; this is the
 130  *      configuration with which this function is associated.
 131  * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
 132  *      can expose more than one interface. If an interface is a member of
 133  *      an IAD, only the first interface of IAD has its entry in the table.
 134  * @os_desc_n: Number of entries in os_desc_table
 135  * @bind: Before the gadget can register, all of its functions bind() to the
 136  *      available resources including string and interface identifiers used
 137  *      in interface or class descriptors; endpoints; I/O buffers; and so on.
 138  * @unbind: Reverses @bind; called as a side effect of unregistering the
 139  *      driver which added this function.
 140  * @free_func: free the struct usb_function.
 141  * @mod: (internal) points to the module that created this structure.
 142  * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
 143  *      initialize usb_ep.driver data at this time (when it is used).
 144  *      Note that setting an interface to its current altsetting resets
 145  *      interface state, and that all interfaces have a disabled state.
 146  * @get_alt: Returns the active altsetting.  If this is not provided,
 147  *      then only altsetting zero is supported.
 148  * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
 149  *      include host resetting or reconfiguring the gadget, and disconnection.
 150  * @setup: Used for interface-specific control requests.
 151  * @req_match: Tests if a given class request can be handled by this function.
 152  * @suspend: Notifies functions when the host stops sending USB traffic.
 153  * @resume: Notifies functions when the host restarts USB traffic.
 154  * @get_status: Returns function status as a reply to
 155  *      GetStatus() request when the recipient is Interface.
 156  * @func_suspend: callback to be called when
 157  *      SetFeature(FUNCTION_SUSPEND) is reseived
 158  *
 159  * A single USB function uses one or more interfaces, and should in most
 160  * cases support operation at both full and high speeds.  Each function is
 161  * associated by @usb_add_function() with a one configuration; that function
 162  * causes @bind() to be called so resources can be allocated as part of
 163  * setting up a gadget driver.  Those resources include endpoints, which
 164  * should be allocated using @usb_ep_autoconfig().
 165  *
 166  * To support dual speed operation, a function driver provides descriptors
 167  * for both high and full speed operation.  Except in rare cases that don't
 168  * involve bulk endpoints, each speed needs different endpoint descriptors.
 169  *
 170  * Function drivers choose their own strategies for managing instance data.
 171  * The simplest strategy just declares it "static', which means the function
 172  * can only be activated once.  If the function needs to be exposed in more
 173  * than one configuration at a given speed, it needs to support multiple
 174  * usb_function structures (one for each configuration).
 175  *
 176  * A more complex strategy might encapsulate a @usb_function structure inside
 177  * a driver-specific instance structure to allows multiple activations.  An
 178  * example of multiple activations might be a CDC ACM function that supports
 179  * two or more distinct instances within the same configuration, providing
 180  * several independent logical data links to a USB host.
 181  */
 182
 183 struct usb_function {
 184         const char                      *name;
 185         struct usb_gadget_strings       **strings;
 186         struct usb_descriptor_header    **fs_descriptors;
 187         struct usb_descriptor_header    **hs_descriptors;
 188         struct usb_descriptor_header    **ss_descriptors;
 189
 190         struct usb_configuration        *config;
 191
 192         struct usb_os_desc_table        *os_desc_table;
 193         unsigned                        os_desc_n;
 194
 195         /* REVISIT:  bind() functions can be marked __init, which
 196          * makes trouble for section mismatch analysis.  See if
 197          * we can't restructure things to avoid mismatching.
 198          * Related:  unbind() may kfree() but bind() won't...
 199          */
 200
 201         /* configuration management:  bind/unbind */
 202         int                     (*bind)(struct usb_configuration *,
 203                                         struct usb_function *);
 204         void                    (*unbind)(struct usb_configuration *,
 205                                         struct usb_function *);
 206         void                    (*free_func)(struct usb_function *f);
 207         struct module           *mod;
 208
 209         /* runtime state management */
 210         int                     (*set_alt)(struct usb_function *,
 211                                         unsigned interface, unsigned alt);
 212         int                     (*get_alt)(struct usb_function *,
 213                                         unsigned interface);
 214         void                    (*disable)(struct usb_function *);
 215         int                     (*setup)(struct usb_function *,
 216                                         const struct usb_ctrlrequest *);
 217         bool                    (*req_match)(struct usb_function *,
 218                                         const struct usb_ctrlrequest *);
 219         void                    (*suspend)(struct usb_function *);
 220         void                    (*resume)(struct usb_function *);
 221
 222         /* USB 3.0 additions */
 223         int                     (*get_status)(struct usb_function *);
 224         int                     (*func_suspend)(struct usb_function *,
 225                                                 u8 suspend_opt);
 226         /* private: */
 227         /* internals */
 228         struct list_head                list;
 229         DECLARE_BITMAP(endpoints, 32);
 230         const struct usb_function_instance *fi;
 231
 232         unsigned int            bind_deactivated:1;
 233 };
 234
 235 int usb_add_function(struct usb_configuration *, struct usb_function *);
 236
 237 int usb_function_deactivate(struct usb_function *);
 238 int usb_function_activate(struct usb_function *);
 239
 240 int usb_interface_id(struct usb_configuration *, struct usb_function *);
 241
 242 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
 243                         struct usb_ep *_ep);
 244
 245 #define MAX_CONFIG_INTERFACES           16      /* arbitrary; max 255 */
 246
 247 /**
 248  * struct usb_configuration - represents one gadget configuration
 249  * @label: For diagnostics, describes the configuration.
 250  * @strings: Tables of strings, keyed by identifiers assigned during @bind()
 251  *      and by language IDs provided in control requests.
 252  * @descriptors: Table of descriptors preceding all function descriptors.
 253  *      Examples include OTG and vendor-specific descriptors.
 254  * @unbind: Reverses @bind; called as a side effect of unregistering the
 255  *      driver which added this configuration.
 256  * @setup: Used to delegate control requests that aren't handled by standard
 257  *      device infrastructure or directed at a specific interface.
 258  * @bConfigurationValue: Copied into configuration descriptor.
 259  * @iConfiguration: Copied into configuration descriptor.
 260  * @bmAttributes: Copied into configuration descriptor.
 261  * @MaxPower: Power consumtion in mA. Used to compute bMaxPower in the
 262  *      configuration descriptor after considering the bus speed.
 263  * @cdev: assigned by @usb_add_config() before calling @bind(); this is
 264  *      the device associated with this configuration.
 265  *
 266  * Configurations are building blocks for gadget drivers structured around
 267  * function drivers.  Simple USB gadgets require only one function and one
 268  * configuration, and handle dual-speed hardware by always providing the same
 269  * functionality.  Slightly more complex gadgets may have more than one
 270  * single-function configuration at a given speed; or have configurations
 271  * that only work at one speed.
 272  *
 273  * Composite devices are, by definition, ones with configurations which
 274  * include more than one function.
 275  *
 276  * The lifecycle of a usb_configuration includes allocation, initialization
 277  * of the fields described above, and calling @usb_add_config() to set up
 278  * internal data and bind it to a specific device.  The configuration's
 279  * @bind() method is then used to initialize all the functions and then
 280  * call @usb_add_function() for them.
 281  *
 282  * Those functions would normally be independent of each other, but that's
 283  * not mandatory.  CDC WMC devices are an example where functions often
 284  * depend on other functions, with some functions subsidiary to others.
 285  * Such interdependency may be managed in any way, so long as all of the
 286  * descriptors complete by the time the composite driver returns from
 287  * its bind() routine.
 288  */
 289 struct usb_configuration {
 290         const char                      *label;
 291         struct usb_gadget_strings       **strings;
 292         const struct usb_descriptor_header **descriptors;
 293
 294         /* REVISIT:  bind() functions can be marked __init, which
 295          * makes trouble for section mismatch analysis.  See if
 296          * we can't restructure things to avoid mismatching...
 297          */
 298
 299         /* configuration management: unbind/setup */
 300         void                    (*unbind)(struct usb_configuration *);
 301         int                     (*setup)(struct usb_configuration *,
 302                                         const struct usb_ctrlrequest *);
 303
 304         /* fields in the config descriptor */
 305         u8                      bConfigurationValue;
 306         u8                      iConfiguration;
 307         u8                      bmAttributes;
 308         u16                     MaxPower;
 309
 310         struct usb_composite_dev        *cdev;
 311
 312         /* private: */
 313         /* internals */
 314         struct list_head        list;
 315         struct list_head        functions;
 316         u8                      next_interface_id;
 317         unsigned                superspeed:1;
 318         unsigned                highspeed:1;
 319         unsigned                fullspeed:1;
 320         struct usb_function     *interface[MAX_CONFIG_INTERFACES];
 321 };
 322
 323 int usb_add_config(struct usb_composite_dev *,
 324                 struct usb_configuration *,
 325                 int (*)(struct usb_configuration *));
 326
 327 void usb_remove_config(struct usb_composite_dev *,
 328                 struct usb_configuration *);
 329
 330 /* predefined index for usb_composite_driver */
 331 enum {
 332         USB_GADGET_MANUFACTURER_IDX     = 0,
 333         USB_GADGET_PRODUCT_IDX,
 334         USB_GADGET_SERIAL_IDX,
 335         USB_GADGET_FIRST_AVAIL_IDX,
 336 };
 337
 338 /**
 339  * struct usb_composite_driver - groups configurations into a gadget
 340  * @name: For diagnostics, identifies the driver.
 341  * @dev: Template descriptor for the device, including default device
 342  *      identifiers.
 343  * @strings: tables of strings, keyed by identifiers assigned during @bind
 344  *      and language IDs provided in control requests. Note: The first entries
 345  *      are predefined. The first entry that may be used is
 346  *      USB_GADGET_FIRST_AVAIL_IDX
 347  * @max_speed: Highest speed the driver supports.
 348  * @needs_serial: set to 1 if the gadget needs userspace to provide
 349  *      a serial number.  If one is not provided, warning will be printed.
 350  * @bind: (REQUIRED) Used to allocate resources that are shared across the
 351  *      whole device, such as string IDs, and add its configurations using
 352  *      @usb_add_config(). This may fail by returning a negative errno
 353  *      value; it should return zero on successful initialization.
 354  * @unbind: Reverses @bind; called as a side effect of unregistering
 355  *      this driver.
 356  * @disconnect: optional driver disconnect method
 357  * @suspend: Notifies when the host stops sending USB traffic,
 358  *      after function notifications
 359  * @resume: Notifies configuration when the host restarts USB traffic,
 360  *      before function notifications
 361  * @gadget_driver: Gadget driver controlling this driver
 362  *
 363  * Devices default to reporting self powered operation.  Devices which rely
 364  * on bus powered operation should report this in their @bind method.
 365  *
 366  * Before returning from @bind, various fields in the template descriptor
 367  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
 368  * normally to bind the appropriate host side driver, and the three strings
 369  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
 370  * meaningful device identifiers.  (The strings will not be defined unless
 371  * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
 372  * is also reported, as defined by the underlying controller driver.
 373  */
 374 struct usb_composite_driver {
 375         const char                              *name;
 376         const struct usb_device_descriptor      *dev;
 377         struct usb_gadget_strings               **strings;
 378         enum usb_device_speed                   max_speed;
 379         unsigned                needs_serial:1;
 380
 381         int                     (*bind)(struct usb_composite_dev *cdev);
 382         int                     (*unbind)(struct usb_composite_dev *);
 383
 384         void                    (*disconnect)(struct usb_composite_dev *);
 385
 386         /* global suspend hooks */
 387         void                    (*suspend)(struct usb_composite_dev *);
 388         void                    (*resume)(struct usb_composite_dev *);
 389         struct usb_gadget_driver                gadget_driver;
 390 };
 391
 392 extern int usb_composite_probe(struct usb_composite_driver *driver);
 393 extern void usb_composite_unregister(struct usb_composite_driver *driver);
 394
 395 /**
 396  * module_usb_composite_driver() - Helper macro for registering a USB gadget
 397  * composite driver
 398  * @__usb_composite_driver: usb_composite_driver struct
 399  *
 400  * Helper macro for USB gadget composite drivers which do not do anything
 401  * special in module init/exit. This eliminates a lot of boilerplate. Each
 402  * module may only use this macro once, and calling it replaces module_init()
 403  * and module_exit()
 404  */
 405 #define module_usb_composite_driver(__usb_composite_driver) \
 406         module_driver(__usb_composite_driver, usb_composite_probe, \
 407                        usb_composite_unregister)
 408
 409 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
 410 extern int composite_dev_prepare(struct usb_composite_driver *composite,
 411                 struct usb_composite_dev *cdev);
 412 extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
 413                                          struct usb_ep *ep0);
 414 void composite_dev_cleanup(struct usb_composite_dev *cdev);
 415
 416 static inline struct usb_composite_driver *to_cdriver(
 417                 struct usb_gadget_driver *gdrv)
 418 {
 419         return container_of(gdrv, struct usb_composite_driver, gadget_driver);
 420 }
 421
 422 #define OS_STRING_QW_SIGN_LEN           14
 423 #define OS_STRING_IDX                   0xEE
 424
 425 /**
 426  * struct usb_composite_device - represents one composite usb gadget
 427  * @gadget: read-only, abstracts the gadget's usb peripheral controller
 428  * @req: used for control responses; buffer is pre-allocated
 429  * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
 430  * @config: the currently active configuration
 431  * @qw_sign: qwSignature part of the OS string
 432  * @b_vendor_code: bMS_VendorCode part of the OS string
 433  * @use_os_string: false by default, interested gadgets set it
 434  * @os_desc_config: the configuration to be used with OS descriptors
 435  * @setup_pending: true when setup request is queued but not completed
 436  * @os_desc_pending: true when os_desc request is queued but not completed
 437  *
 438  * One of these devices is allocated and initialized before the
 439  * associated device driver's bind() is called.
 440  *
 441  * OPEN ISSUE:  it appears that some WUSB devices will need to be
 442  * built by combining a normal (wired) gadget with a wireless one.
 443  * This revision of the gadget framework should probably try to make
 444  * sure doing that won't hurt too much.
 445  *
 446  * One notion for how to handle Wireless USB devices involves:
 447  * (a) a second gadget here, discovery mechanism TBD, but likely
 448  *     needing separate "register/unregister WUSB gadget" calls;
 449  * (b) updates to usb_gadget to include flags "is it wireless",
 450  *     "is it wired", plus (presumably in a wrapper structure)
 451  *     bandgroup and PHY info;
 452  * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
 453  *     wireless-specific parameters like maxburst and maxsequence;
 454  * (d) configurations that are specific to wireless links;
 455  * (e) function drivers that understand wireless configs and will
 456  *     support wireless for (additional) function instances;
 457  * (f) a function to support association setup (like CBAF), not
 458  *     necessarily requiring a wireless adapter;
 459  * (g) composite device setup that can create one or more wireless
 460  *     configs, including appropriate association setup support;
 461  * (h) more, TBD.
 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         /* private: */
 477         /* internals */
 478         unsigned int                    suspended:1;
 479         struct usb_device_descriptor    desc;
 480         struct list_head                configs;
 481         struct list_head                gstrings;
 482         struct usb_composite_driver     *driver;
 483         u8                              next_string_id;
 484         char                            *def_manufacturer;
 485
 486         /* the gadget driver won't enable the data pullup
 487          * while the deactivation count is nonzero.
 488          */
 489         unsigned                        deactivations;
 490
 491         /* the composite driver won't complete the control transfer's
 492          * data/status stages till delayed_status is zero.
 493          */
 494         int                             delayed_status;
 495
 496         /* protects deactivations and delayed_status counts*/
 497         spinlock_t                      lock;
 498
 499         unsigned                        setup_pending:1;
 500         unsigned                        os_desc_pending:1;
 501 };
 502
 503 extern int usb_string_id(struct usb_composite_dev *c);
 504 extern int usb_string_ids_tab(struct usb_composite_dev *c,
 505                               struct usb_string *str);
 506 extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
 507                 struct usb_gadget_strings **sp, unsigned n_strings);
 508
 509 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
 510
 511 extern void composite_disconnect(struct usb_gadget *gadget);
 512 extern int composite_setup(struct usb_gadget *gadget,
 513                 const struct usb_ctrlrequest *ctrl);
 514 extern void composite_suspend(struct usb_gadget *gadget);
 515 extern void composite_resume(struct usb_gadget *gadget);
 516
 517 /*
 518  * Some systems will need runtime overrides for the  product identifiers
 519  * published in the device descriptor, either numbers or strings or both.
 520  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
 521  */
 522 struct usb_composite_overwrite {
 523         u16     idVendor;
 524         u16     idProduct;
 525         u16     bcdDevice;
 526         char    *serial_number;
 527         char    *manufacturer;
 528         char    *product;
 529 };
 530 #define USB_GADGET_COMPOSITE_OPTIONS()                                  \
 531         static struct usb_composite_overwrite coverwrite;               \
 532                                                                         \
 533         module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
 534         MODULE_PARM_DESC(idVendor, "USB Vendor ID");                    \
 535                                                                         \
 536         module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
 537         MODULE_PARM_DESC(idProduct, "USB Product ID");                  \
 538                                                                         \
 539         module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
 540         MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");        \
 541                                                                         \
 542         module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
 543                         S_IRUGO); \
 544         MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");         \
 545                                                                         \
 546         module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
 547                         S_IRUGO); \
 548         MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");     \
 549                                                                         \
 550         module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
 551         MODULE_PARM_DESC(iProduct, "USB Product string")
 552
 553 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 554                 struct usb_composite_overwrite *covr);
 555
 556 static inline u16 get_default_bcdDevice(void)
 557 {
 558         u16 bcdDevice;
 559
 560         bcdDevice = bin2bcd((LINUX_VERSION_CODE >> 16 & 0xff)) << 8;
 561         bcdDevice |= bin2bcd((LINUX_VERSION_CODE >> 8 & 0xff));
 562         return bcdDevice;
 563 }
 564
 565 struct usb_function_driver {
 566         const char *name;
 567         struct module *mod;
 568         struct list_head list;
 569         struct usb_function_instance *(*alloc_inst)(void);
 570         struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
 571 };
 572
 573 struct usb_function_instance {
 574         struct config_group group;
 575         struct list_head cfs_list;
 576         struct usb_function_driver *fd;
 577         int (*set_inst_name)(struct usb_function_instance *inst,
 578                               const char *name);
 579         void (*free_func_inst)(struct usb_function_instance *inst);
 580 };
 581
 582 void usb_function_unregister(struct usb_function_driver *f);
 583 int usb_function_register(struct usb_function_driver *newf);
 584 void usb_put_function_instance(struct usb_function_instance *fi);
 585 void usb_put_function(struct usb_function *f);
 586 struct usb_function_instance *usb_get_function_instance(const char *name);
 587 struct usb_function *usb_get_function(struct usb_function_instance *fi);
 588
 589 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
 590                 int val);
 591 int usb_add_config_only(struct usb_composite_dev *cdev,
 592                 struct usb_configuration *config);
 593 void usb_remove_function(struct usb_configuration *c, struct usb_function *f);
 594
 595 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)           \
 596         static struct usb_function_driver _name ## usb_func = {         \
 597                 .name = __stringify(_name),                             \
 598                 .mod  = THIS_MODULE,                                    \
 599                 .alloc_inst = _inst_alloc,                              \
 600                 .alloc_func = _func_alloc,                              \
 601         };                                                              \
 602         MODULE_ALIAS("usbfunc:"__stringify(_name));
 603
 604 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc)      \
 605         DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc)           \
 606         static int __init _name ## mod_init(void)                       \
 607         {                                                               \
 608                 return usb_function_register(&_name ## usb_func);       \
 609         }                                                               \
 610         static void __exit _name ## mod_exit(void)                      \
 611         {                                                               \
 612                 usb_function_unregister(&_name ## usb_func);            \
 613         }                                                               \
 614         module_init(_name ## mod_init);                                 \
 615         module_exit(_name ## mod_exit)
 616
 617 /* messaging utils */
 618 #define DBG(d, fmt, args...) \
 619         dev_dbg(&(d)->gadget->dev , fmt , ## args)
 620 #define VDBG(d, fmt, args...) \
 621         dev_vdbg(&(d)->gadget->dev , fmt , ## args)
 622 #define ERROR(d, fmt, args...) \
 623         dev_err(&(d)->gadget->dev , fmt , ## args)
 624 #define WARNING(d, fmt, args...) \
 625         dev_warn(&(d)->gadget->dev , fmt , ## args)
 626 #define INFO(d, fmt, args...) \
 627         dev_info(&(d)->gadget->dev , fmt , ## args)
 628
 629 #endif  /* __LINUX_USB_COMPOSITE_H */