1 // SPDX-License-Identifier: GPL-2.0+
3 * composite.h -- framework for usb gadgets which are composite devices
5 * Copyright (C) 2006-2008 David Brownell
8 #ifndef __LINUX_USB_COMPOSITE_H
9 #define __LINUX_USB_COMPOSITE_H
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.
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.
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>
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().
39 #define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */
41 /* big enough to hold our biggest descriptor */
42 #define USB_COMP_EP0_BUFSIZ 4096
44 /* OS feature descriptor length <= 4kB */
45 #define USB_COMP_EP0_OS_DESC_BUFSIZ 4096
47 #define USB_MS_TO_HS_INTERVAL(x) (ilog2((x * 1000 / 125)) + 1)
48 struct usb_configuration;
51 * struct usb_os_desc_ext_prop - describes one "Extended Property"
52 * @entry: used to keep a list of extended properties
53 * @type: Extended Property type
54 * @name_len: Extended Property unicode name length, including terminating '\0'
55 * @name: Extended Property name
56 * @data_len: Length of Extended Property blob (for unicode store double len)
57 * @data: Extended Property blob
58 * @item: Represents this Extended Property in configfs
60 struct usb_os_desc_ext_prop {
61 struct list_head entry;
67 struct config_item item;
71 * struct usb_os_desc - describes OS descriptors associated with one interface
72 * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
73 * @ext_prop: Extended Properties list
74 * @ext_prop_len: Total length of Extended Properties blobs
75 * @ext_prop_count: Number of Extended Properties
76 * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
77 * @group: Represents OS descriptors associated with an interface in configfs
78 * @owner: Module associated with this OS descriptor
82 struct list_head ext_prop;
85 struct mutex *opts_mutex;
86 struct config_group group;
91 * struct usb_os_desc_table - describes OS descriptors associated with one
92 * interface of a usb_function
93 * @if_id: Interface id
94 * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
97 * Each interface can have at most one "Extended Compatibility ID" and a
98 * number of "Extended Properties".
100 struct usb_os_desc_table {
102 struct usb_os_desc *os_desc;
106 * struct usb_function - describes one function of a configuration
107 * @name: For diagnostics, identifies the function.
108 * @strings: tables of strings, keyed by identifiers assigned during bind()
109 * and by language IDs provided in control requests
110 * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
111 * string identifiers assigned during @bind(). If this pointer is null,
112 * the function will not be available at full speed (or at low speed).
113 * @hs_descriptors: Table of high speed descriptors, using interface and
114 * string identifiers assigned during @bind(). If this pointer is null,
115 * the function will not be available at high speed.
116 * @ss_descriptors: Table of super speed descriptors, using interface and
117 * string identifiers assigned during @bind(). If this
118 * pointer is null after initiation, the function will not
119 * be available at super speed.
120 * @ssp_descriptors: Table of super speed plus descriptors, using
121 * interface and string identifiers assigned during @bind(). If
122 * this pointer is null after initiation, the function will not
123 * be available at super speed plus.
124 * @config: assigned when @usb_add_function() is called; this is the
125 * configuration with which this function is associated.
126 * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
127 * can expose more than one interface. If an interface is a member of
128 * an IAD, only the first interface of IAD has its entry in the table.
129 * @os_desc_n: Number of entries in os_desc_table
130 * @bind: Before the gadget can register, all of its functions bind() to the
131 * available resources including string and interface identifiers used
132 * in interface or class descriptors; endpoints; I/O buffers; and so on.
133 * @unbind: Reverses @bind; called as a side effect of unregistering the
134 * driver which added this function.
135 * @free_func: free the struct usb_function.
136 * @mod: (internal) points to the module that created this structure.
137 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
138 * initialize usb_ep.driver data at this time (when it is used).
139 * Note that setting an interface to its current altsetting resets
140 * interface state, and that all interfaces have a disabled state.
141 * @get_alt: Returns the active altsetting. If this is not provided,
142 * then only altsetting zero is supported.
143 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons
144 * include host resetting or reconfiguring the gadget, and disconnection.
145 * @setup: Used for interface-specific control requests.
146 * @req_match: Tests if a given class request can be handled by this function.
147 * @suspend: Notifies functions when the host stops sending USB traffic.
148 * @resume: Notifies functions when the host restarts USB traffic.
149 * @get_status: Returns function status as a reply to
150 * GetStatus() request when the recipient is Interface.
151 * @func_suspend: callback to be called when
152 * SetFeature(FUNCTION_SUSPEND) is reseived
153 * @func_suspended: Indicates whether the function is in function suspend state.
154 * @func_wakeup_armed: Indicates whether the function is armed by the host for
157 * A single USB function uses one or more interfaces, and should in most
158 * cases support operation at both full and high speeds. Each function is
159 * associated by @usb_add_function() with a one configuration; that function
160 * causes @bind() to be called so resources can be allocated as part of
161 * setting up a gadget driver. Those resources include endpoints, which
162 * should be allocated using @usb_ep_autoconfig().
164 * To support dual speed operation, a function driver provides descriptors
165 * for both high and full speed operation. Except in rare cases that don't
166 * involve bulk endpoints, each speed needs different endpoint descriptors.
168 * Function drivers choose their own strategies for managing instance data.
169 * The simplest strategy just declares it "static', which means the function
170 * can only be activated once. If the function needs to be exposed in more
171 * than one configuration at a given speed, it needs to support multiple
172 * usb_function structures (one for each configuration).
174 * A more complex strategy might encapsulate a @usb_function structure inside
175 * a driver-specific instance structure to allows multiple activations. An
176 * example of multiple activations might be a CDC ACM function that supports
177 * two or more distinct instances within the same configuration, providing
178 * several independent logical data links to a USB host.
181 struct usb_function {
183 struct usb_gadget_strings **strings;
184 struct usb_descriptor_header **fs_descriptors;
185 struct usb_descriptor_header **hs_descriptors;
186 struct usb_descriptor_header **ss_descriptors;
187 struct usb_descriptor_header **ssp_descriptors;
189 struct usb_configuration *config;
191 struct usb_os_desc_table *os_desc_table;
194 /* REVISIT: bind() functions can be marked __init, which
195 * makes trouble for section mismatch analysis. See if
196 * we can't restructure things to avoid mismatching.
197 * Related: unbind() may kfree() but bind() won't...
200 /* configuration management: bind/unbind */
201 int (*bind)(struct usb_configuration *,
202 struct usb_function *);
203 void (*unbind)(struct usb_configuration *,
204 struct usb_function *);
205 void (*free_func)(struct usb_function *f);
208 /* runtime state management */
209 int (*set_alt)(struct usb_function *,
210 unsigned interface, unsigned alt);
211 int (*get_alt)(struct usb_function *,
213 void (*disable)(struct usb_function *);
214 int (*setup)(struct usb_function *,
215 const struct usb_ctrlrequest *);
216 bool (*req_match)(struct usb_function *,
217 const struct usb_ctrlrequest *,
219 void (*suspend)(struct usb_function *);
220 void (*resume)(struct usb_function *);
222 /* USB 3.0 additions */
223 int (*get_status)(struct usb_function *);
224 int (*func_suspend)(struct usb_function *,
227 bool func_wakeup_armed;
230 struct list_head list;
231 DECLARE_BITMAP(endpoints, 32);
232 const struct usb_function_instance *fi;
234 unsigned int bind_deactivated:1;
237 int usb_add_function(struct usb_configuration *, struct usb_function *);
239 int usb_function_deactivate(struct usb_function *);
240 int usb_function_activate(struct usb_function *);
242 int usb_interface_id(struct usb_configuration *, struct usb_function *);
244 int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
245 struct usb_ep *_ep, u8 alt);
247 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
249 int usb_func_wakeup(struct usb_function *func);
251 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
254 * struct usb_configuration - represents one gadget configuration
255 * @label: For diagnostics, describes the configuration.
256 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
257 * and by language IDs provided in control requests.
258 * @descriptors: Table of descriptors preceding all function descriptors.
259 * Examples include OTG and vendor-specific descriptors.
260 * @unbind: Reverses @bind; called as a side effect of unregistering the
261 * driver which added this configuration.
262 * @setup: Used to delegate control requests that aren't handled by standard
263 * device infrastructure or directed at a specific interface.
264 * @bConfigurationValue: Copied into configuration descriptor.
265 * @iConfiguration: Copied into configuration descriptor.
266 * @bmAttributes: Copied into configuration descriptor.
267 * @MaxPower: Power consumption in mA. Used to compute bMaxPower in the
268 * configuration descriptor after considering the bus speed.
269 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
270 * the device associated with this configuration.
272 * Configurations are building blocks for gadget drivers structured around
273 * function drivers. Simple USB gadgets require only one function and one
274 * configuration, and handle dual-speed hardware by always providing the same
275 * functionality. Slightly more complex gadgets may have more than one
276 * single-function configuration at a given speed; or have configurations
277 * that only work at one speed.
279 * Composite devices are, by definition, ones with configurations which
280 * include more than one function.
282 * The lifecycle of a usb_configuration includes allocation, initialization
283 * of the fields described above, and calling @usb_add_config() to set up
284 * internal data and bind it to a specific device. The configuration's
285 * @bind() method is then used to initialize all the functions and then
286 * call @usb_add_function() for them.
288 * Those functions would normally be independent of each other, but that's
289 * not mandatory. CDC WMC devices are an example where functions often
290 * depend on other functions, with some functions subsidiary to others.
291 * Such interdependency may be managed in any way, so long as all of the
292 * descriptors complete by the time the composite driver returns from
293 * its bind() routine.
295 struct usb_configuration {
297 struct usb_gadget_strings **strings;
298 const struct usb_descriptor_header **descriptors;
300 /* REVISIT: bind() functions can be marked __init, which
301 * makes trouble for section mismatch analysis. See if
302 * we can't restructure things to avoid mismatching...
305 /* configuration management: unbind/setup */
306 void (*unbind)(struct usb_configuration *);
307 int (*setup)(struct usb_configuration *,
308 const struct usb_ctrlrequest *);
310 /* fields in the config descriptor */
311 u8 bConfigurationValue;
316 struct usb_composite_dev *cdev;
320 struct list_head list;
321 struct list_head functions;
322 u8 next_interface_id;
323 unsigned superspeed:1;
324 unsigned highspeed:1;
325 unsigned fullspeed:1;
326 unsigned superspeed_plus:1;
327 struct usb_function *interface[MAX_CONFIG_INTERFACES];
330 int usb_add_config(struct usb_composite_dev *,
331 struct usb_configuration *,
332 int (*)(struct usb_configuration *));
334 void usb_remove_config(struct usb_composite_dev *,
335 struct usb_configuration *);
337 /* predefined index for usb_composite_driver */
339 USB_GADGET_MANUFACTURER_IDX = 0,
340 USB_GADGET_PRODUCT_IDX,
341 USB_GADGET_SERIAL_IDX,
342 USB_GADGET_FIRST_AVAIL_IDX,
346 * struct usb_composite_driver - groups configurations into a gadget
347 * @name: For diagnostics, identifies the driver.
348 * @dev: Template descriptor for the device, including default device
350 * @strings: tables of strings, keyed by identifiers assigned during @bind
351 * and language IDs provided in control requests. Note: The first entries
352 * are predefined. The first entry that may be used is
353 * USB_GADGET_FIRST_AVAIL_IDX
354 * @max_speed: Highest speed the driver supports.
355 * @needs_serial: set to 1 if the gadget needs userspace to provide
356 * a serial number. If one is not provided, warning will be printed.
357 * @bind: (REQUIRED) Used to allocate resources that are shared across the
358 * whole device, such as string IDs, and add its configurations using
359 * @usb_add_config(). This may fail by returning a negative errno
360 * value; it should return zero on successful initialization.
361 * @unbind: Reverses @bind; called as a side effect of unregistering
363 * @disconnect: optional driver disconnect method
364 * @suspend: Notifies when the host stops sending USB traffic,
365 * after function notifications
366 * @resume: Notifies configuration when the host restarts USB traffic,
367 * before function notifications
368 * @gadget_driver: Gadget driver controlling this driver
370 * Devices default to reporting self powered operation. Devices which rely
371 * on bus powered operation should report this in their @bind method.
373 * Before returning from @bind, various fields in the template descriptor
374 * may be overridden. These include the idVendor/idProduct/bcdDevice values
375 * normally to bind the appropriate host side driver, and the three strings
376 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
377 * meaningful device identifiers. (The strings will not be defined unless
378 * they are defined in @dev and @strings.) The correct ep0 maxpacket size
379 * is also reported, as defined by the underlying controller driver.
381 struct usb_composite_driver {
383 const struct usb_device_descriptor *dev;
384 struct usb_gadget_strings **strings;
385 enum usb_device_speed max_speed;
386 unsigned needs_serial:1;
388 int (*bind)(struct usb_composite_dev *cdev);
389 int (*unbind)(struct usb_composite_dev *);
391 void (*disconnect)(struct usb_composite_dev *);
393 /* global suspend hooks */
394 void (*suspend)(struct usb_composite_dev *);
395 void (*resume)(struct usb_composite_dev *);
396 struct usb_gadget_driver gadget_driver;
399 extern int usb_composite_probe(struct usb_composite_driver *driver);
400 extern void usb_composite_unregister(struct usb_composite_driver *driver);
403 * module_usb_composite_driver() - Helper macro for registering a USB gadget
405 * @__usb_composite_driver: usb_composite_driver struct
407 * Helper macro for USB gadget composite drivers which do not do anything
408 * special in module init/exit. This eliminates a lot of boilerplate. Each
409 * module may only use this macro once, and calling it replaces module_init()
412 #define module_usb_composite_driver(__usb_composite_driver) \
413 module_driver(__usb_composite_driver, usb_composite_probe, \
414 usb_composite_unregister)
416 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
417 extern int composite_dev_prepare(struct usb_composite_driver *composite,
418 struct usb_composite_dev *cdev);
419 extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
421 void composite_dev_cleanup(struct usb_composite_dev *cdev);
422 void check_remote_wakeup_config(struct usb_gadget *g,
423 struct usb_configuration *c);
425 static inline struct usb_composite_driver *to_cdriver(
426 struct usb_gadget_driver *gdrv)
428 return container_of(gdrv, struct usb_composite_driver, gadget_driver);
431 #define OS_STRING_QW_SIGN_LEN 14
432 #define OS_STRING_IDX 0xEE
435 * struct usb_composite_dev - represents one composite usb gadget
436 * @gadget: read-only, abstracts the gadget's usb peripheral controller
437 * @req: used for control responses; buffer is pre-allocated
438 * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
439 * @config: the currently active configuration
440 * @qw_sign: qwSignature part of the OS string
441 * @b_vendor_code: bMS_VendorCode part of the OS string
442 * @use_os_string: false by default, interested gadgets set it
443 * @bcd_webusb_version: 0x0100 by default, WebUSB specification version
444 * @b_webusb_vendor_code: 0x0 by default, vendor code for WebUSB
445 * @landing_page: empty by default, landing page to announce in WebUSB
446 * @use_webusb:: false by default, interested gadgets set it
447 * @os_desc_config: the configuration to be used with OS descriptors
448 * @setup_pending: true when setup request is queued but not completed
449 * @os_desc_pending: true when os_desc request is queued but not completed
451 * One of these devices is allocated and initialized before the
452 * associated device driver's bind() is called.
454 * OPEN ISSUE: it appears that some WUSB devices will need to be
455 * built by combining a normal (wired) gadget with a wireless one.
456 * This revision of the gadget framework should probably try to make
457 * sure doing that won't hurt too much.
459 * One notion for how to handle Wireless USB devices involves:
461 * (a) a second gadget here, discovery mechanism TBD, but likely
462 * needing separate "register/unregister WUSB gadget" calls;
463 * (b) updates to usb_gadget to include flags "is it wireless",
464 * "is it wired", plus (presumably in a wrapper structure)
465 * bandgroup and PHY info;
466 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
467 * wireless-specific parameters like maxburst and maxsequence;
468 * (d) configurations that are specific to wireless links;
469 * (e) function drivers that understand wireless configs and will
470 * support wireless for (additional) function instances;
471 * (f) a function to support association setup (like CBAF), not
472 * necessarily requiring a wireless adapter;
473 * (g) composite device setup that can create one or more wireless
474 * configs, including appropriate association setup support;
477 struct usb_composite_dev {
478 struct usb_gadget *gadget;
479 struct usb_request *req;
480 struct usb_request *os_desc_req;
482 struct usb_configuration *config;
484 /* OS String is a custom (yet popular) extension to the USB standard. */
485 u8 qw_sign[OS_STRING_QW_SIGN_LEN];
487 struct usb_configuration *os_desc_config;
488 unsigned int use_os_string:1;
491 u16 bcd_webusb_version;
492 u8 b_webusb_vendor_code;
493 char landing_page[WEBUSB_URL_RAW_MAX_LENGTH];
494 unsigned int use_webusb:1;
498 unsigned int suspended:1;
499 struct usb_device_descriptor desc;
500 struct list_head configs;
501 struct list_head gstrings;
502 struct usb_composite_driver *driver;
504 char *def_manufacturer;
505 struct usb_string *usb_strings;
507 /* the gadget driver won't enable the data pullup
508 * while the deactivation count is nonzero.
510 unsigned deactivations;
512 /* the composite driver won't complete the control transfer's
513 * data/status stages till delayed_status is zero.
517 /* protects deactivations and delayed_status counts*/
521 unsigned int setup_pending:1;
522 unsigned int os_desc_pending:1;
525 extern int usb_string_id(struct usb_composite_dev *c);
526 extern int usb_string_ids_tab(struct usb_composite_dev *c,
527 struct usb_string *str);
528 extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
529 struct usb_gadget_strings **sp, unsigned n_strings);
531 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
533 extern void composite_disconnect(struct usb_gadget *gadget);
534 extern void composite_reset(struct usb_gadget *gadget);
536 extern int composite_setup(struct usb_gadget *gadget,
537 const struct usb_ctrlrequest *ctrl);
538 extern void composite_suspend(struct usb_gadget *gadget);
539 extern void composite_resume(struct usb_gadget *gadget);
542 * Some systems will need runtime overrides for the product identifiers
543 * published in the device descriptor, either numbers or strings or both.
544 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
546 struct usb_composite_overwrite {
554 #define USB_GADGET_COMPOSITE_OPTIONS() \
555 static struct usb_composite_overwrite coverwrite; \
557 module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
558 MODULE_PARM_DESC(idVendor, "USB Vendor ID"); \
560 module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
561 MODULE_PARM_DESC(idProduct, "USB Product ID"); \
563 module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
564 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)"); \
566 module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
568 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string"); \
570 module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
572 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string"); \
574 module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
575 MODULE_PARM_DESC(iProduct, "USB Product string")
577 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
578 struct usb_composite_overwrite *covr);
580 static inline u16 get_default_bcdDevice(void)
584 bcdDevice = bin2bcd(LINUX_VERSION_MAJOR) << 8;
585 bcdDevice |= bin2bcd(LINUX_VERSION_PATCHLEVEL);
589 struct usb_function_driver {
592 struct list_head list;
593 struct usb_function_instance *(*alloc_inst)(void);
594 struct usb_function *(*alloc_func)(struct usb_function_instance *inst);
597 struct usb_function_instance {
598 struct config_group group;
599 struct list_head cfs_list;
600 struct usb_function_driver *fd;
601 int (*set_inst_name)(struct usb_function_instance *inst,
603 void (*free_func_inst)(struct usb_function_instance *inst);
606 void usb_function_unregister(struct usb_function_driver *f);
607 int usb_function_register(struct usb_function_driver *newf);
608 void usb_put_function_instance(struct usb_function_instance *fi);
609 void usb_put_function(struct usb_function *f);
610 struct usb_function_instance *usb_get_function_instance(const char *name);
611 struct usb_function *usb_get_function(struct usb_function_instance *fi);
613 struct usb_configuration *usb_get_config(struct usb_composite_dev *cdev,
615 int usb_add_config_only(struct usb_composite_dev *cdev,
616 struct usb_configuration *config);
617 void usb_remove_function(struct usb_configuration *c, struct usb_function *f);
619 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \
620 static struct usb_function_driver _name ## usb_func = { \
621 .name = __stringify(_name), \
622 .mod = THIS_MODULE, \
623 .alloc_inst = _inst_alloc, \
624 .alloc_func = _func_alloc, \
626 MODULE_ALIAS("usbfunc:"__stringify(_name));
628 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc) \
629 DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \
630 static int __init _name ## mod_init(void) \
632 return usb_function_register(&_name ## usb_func); \
634 static void __exit _name ## mod_exit(void) \
636 usb_function_unregister(&_name ## usb_func); \
638 module_init(_name ## mod_init); \
639 module_exit(_name ## mod_exit)
641 /* messaging utils */
642 #define DBG(d, fmt, args...) \
643 dev_dbg(&(d)->gadget->dev , fmt , ## args)
644 #define VDBG(d, fmt, args...) \
645 dev_vdbg(&(d)->gadget->dev , fmt , ## args)
646 #define ERROR(d, fmt, args...) \
647 dev_err(&(d)->gadget->dev , fmt , ## args)
648 #define WARNING(d, fmt, args...) \
649 dev_warn(&(d)->gadget->dev , fmt , ## args)
650 #define INFO(d, fmt, args...) \
651 dev_info(&(d)->gadget->dev , fmt , ## args)
653 #endif /* __LINUX_USB_COMPOSITE_H */