2 * composite.h -- framework for usb gadgets which are composite devices
4 * Copyright (C) 2006-2008 David Brownell
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.
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.
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
21 #ifndef __LINUX_USB_COMPOSITE_H
22 #define __LINUX_USB_COMPOSITE_H
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.
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.
37 #include <linux/usb/ch9.h>
38 #include <linux/usb/gadget.h>
41 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
42 * wish to delay the data/status stages of the control transfer till they
43 * are ready. The control transfer will then be kept from completing till
44 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
45 * invoke usb_composite_setup_continue().
47 #define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */
49 /* big enough to hold our biggest descriptor */
50 #define USB_COMP_EP0_BUFSIZ 1024
52 struct usb_configuration;
55 * struct usb_function - describes one function of a configuration
56 * @name: For diagnostics, identifies the function.
57 * @strings: tables of strings, keyed by identifiers assigned during bind()
58 * and by language IDs provided in control requests
59 * @descriptors: Table of full (or low) speed descriptors, using interface and
60 * string identifiers assigned during @bind(). If this pointer is null,
61 * the function will not be available at full speed (or at low speed).
62 * @hs_descriptors: Table of high speed descriptors, using interface and
63 * string identifiers assigned during @bind(). If this pointer is null,
64 * the function will not be available at high speed.
65 * @ss_descriptors: Table of super speed descriptors, using interface and
66 * string identifiers assigned during @bind(). If this
67 * pointer is null after initiation, the function will not
68 * be available at super speed.
69 * @config: assigned when @usb_add_function() is called; this is the
70 * configuration with which this function is associated.
71 * @bind: Before the gadget can register, all of its functions bind() to the
72 * available resources including string and interface identifiers used
73 * in interface or class descriptors; endpoints; I/O buffers; and so on.
74 * @unbind: Reverses @bind; called as a side effect of unregistering the
75 * driver which added this function.
76 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
77 * initialize usb_ep.driver data at this time (when it is used).
78 * Note that setting an interface to its current altsetting resets
79 * interface state, and that all interfaces have a disabled state.
80 * @get_alt: Returns the active altsetting. If this is not provided,
81 * then only altsetting zero is supported.
82 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons
83 * include host resetting or reconfiguring the gadget, and disconnection.
84 * @setup: Used for interface-specific control requests.
85 * @suspend: Notifies functions when the host stops sending USB traffic.
86 * @resume: Notifies functions when the host restarts USB traffic.
87 * @get_status: Returns function status as a reply to
88 * GetStatus() request when the recepient is Interface.
89 * @func_suspend: callback to be called when
90 * SetFeature(FUNCTION_SUSPEND) is reseived
92 * A single USB function uses one or more interfaces, and should in most
93 * cases support operation at both full and high speeds. Each function is
94 * associated by @usb_add_function() with a one configuration; that function
95 * causes @bind() to be called so resources can be allocated as part of
96 * setting up a gadget driver. Those resources include endpoints, which
97 * should be allocated using @usb_ep_autoconfig().
99 * To support dual speed operation, a function driver provides descriptors
100 * for both high and full speed operation. Except in rare cases that don't
101 * involve bulk endpoints, each speed needs different endpoint descriptors.
103 * Function drivers choose their own strategies for managing instance data.
104 * The simplest strategy just declares it "static', which means the function
105 * can only be activated once. If the function needs to be exposed in more
106 * than one configuration at a given speed, it needs to support multiple
107 * usb_function structures (one for each configuration).
109 * A more complex strategy might encapsulate a @usb_function structure inside
110 * a driver-specific instance structure to allows multiple activations. An
111 * example of multiple activations might be a CDC ACM function that supports
112 * two or more distinct instances within the same configuration, providing
113 * several independent logical data links to a USB host.
115 struct usb_function {
117 struct usb_gadget_strings **strings;
118 struct usb_descriptor_header **descriptors;
119 struct usb_descriptor_header **hs_descriptors;
120 struct usb_descriptor_header **ss_descriptors;
122 struct usb_configuration *config;
124 /* REVISIT: bind() functions can be marked __init, which
125 * makes trouble for section mismatch analysis. See if
126 * we can't restructure things to avoid mismatching.
127 * Related: unbind() may kfree() but bind() won't...
130 /* configuration management: bind/unbind */
131 int (*bind)(struct usb_configuration *,
132 struct usb_function *);
133 void (*unbind)(struct usb_configuration *,
134 struct usb_function *);
136 /* runtime state management */
137 int (*set_alt)(struct usb_function *,
138 unsigned interface, unsigned alt);
139 int (*get_alt)(struct usb_function *,
141 void (*disable)(struct usb_function *);
142 int (*setup)(struct usb_function *,
143 const struct usb_ctrlrequest *);
144 void (*suspend)(struct usb_function *);
145 void (*resume)(struct usb_function *);
147 /* USB 3.0 additions */
148 int (*get_status)(struct usb_function *);
149 int (*func_suspend)(struct usb_function *,
153 struct list_head list;
154 DECLARE_BITMAP(endpoints, 32);
157 int usb_add_function(struct usb_configuration *, struct usb_function *);
159 int usb_function_deactivate(struct usb_function *);
160 int usb_function_activate(struct usb_function *);
162 int usb_interface_id(struct usb_configuration *, struct usb_function *);
164 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
167 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
170 * struct usb_configuration - represents one gadget configuration
171 * @label: For diagnostics, describes the configuration.
172 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
173 * and by language IDs provided in control requests.
174 * @descriptors: Table of descriptors preceding all function descriptors.
175 * Examples include OTG and vendor-specific descriptors.
176 * @unbind: Reverses @bind; called as a side effect of unregistering the
177 * driver which added this configuration.
178 * @setup: Used to delegate control requests that aren't handled by standard
179 * device infrastructure or directed at a specific interface.
180 * @bConfigurationValue: Copied into configuration descriptor.
181 * @iConfiguration: Copied into configuration descriptor.
182 * @bmAttributes: Copied into configuration descriptor.
183 * @bMaxPower: Copied into configuration descriptor.
184 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
185 * the device associated with this configuration.
187 * Configurations are building blocks for gadget drivers structured around
188 * function drivers. Simple USB gadgets require only one function and one
189 * configuration, and handle dual-speed hardware by always providing the same
190 * functionality. Slightly more complex gadgets may have more than one
191 * single-function configuration at a given speed; or have configurations
192 * that only work at one speed.
194 * Composite devices are, by definition, ones with configurations which
195 * include more than one function.
197 * The lifecycle of a usb_configuration includes allocation, initialization
198 * of the fields described above, and calling @usb_add_config() to set up
199 * internal data and bind it to a specific device. The configuration's
200 * @bind() method is then used to initialize all the functions and then
201 * call @usb_add_function() for them.
203 * Those functions would normally be independent of each other, but that's
204 * not mandatory. CDC WMC devices are an example where functions often
205 * depend on other functions, with some functions subsidiary to others.
206 * Such interdependency may be managed in any way, so long as all of the
207 * descriptors complete by the time the composite driver returns from
208 * its bind() routine.
210 struct usb_configuration {
212 struct usb_gadget_strings **strings;
213 const struct usb_descriptor_header **descriptors;
215 /* REVISIT: bind() functions can be marked __init, which
216 * makes trouble for section mismatch analysis. See if
217 * we can't restructure things to avoid mismatching...
220 /* configuration management: unbind/setup */
221 void (*unbind)(struct usb_configuration *);
222 int (*setup)(struct usb_configuration *,
223 const struct usb_ctrlrequest *);
225 /* fields in the config descriptor */
226 u8 bConfigurationValue;
231 struct usb_composite_dev *cdev;
235 struct list_head list;
236 struct list_head functions;
237 u8 next_interface_id;
238 unsigned superspeed:1;
239 unsigned highspeed:1;
240 unsigned fullspeed:1;
241 struct usb_function *interface[MAX_CONFIG_INTERFACES];
244 int usb_add_config(struct usb_composite_dev *,
245 struct usb_configuration *,
246 int (*)(struct usb_configuration *));
248 void usb_remove_config(struct usb_composite_dev *,
249 struct usb_configuration *);
251 /* predefined index for usb_composite_driver */
253 USB_GADGET_MANUFACTURER_IDX = 0,
254 USB_GADGET_PRODUCT_IDX,
255 USB_GADGET_SERIAL_IDX,
256 USB_GADGET_FIRST_AVAIL_IDX,
260 * struct usb_composite_driver - groups configurations into a gadget
261 * @name: For diagnostics, identifies the driver.
262 * @dev: Template descriptor for the device, including default device
264 * @strings: tables of strings, keyed by identifiers assigned during @bind
265 * and language IDs provided in control requests. Note: The first entries
266 * are predefined. The first entry that may be used is
267 * USB_GADGET_FIRST_AVAIL_IDX
268 * @max_speed: Highest speed the driver supports.
269 * @needs_serial: set to 1 if the gadget needs userspace to provide
270 * a serial number. If one is not provided, warning will be printed.
271 * @bind: (REQUIRED) Used to allocate resources that are shared across the
272 * whole device, such as string IDs, and add its configurations using
273 * @usb_add_config(). This may fail by returning a negative errno
274 * value; it should return zero on successful initialization.
275 * @unbind: Reverses @bind; called as a side effect of unregistering
277 * @disconnect: optional driver disconnect method
278 * @suspend: Notifies when the host stops sending USB traffic,
279 * after function notifications
280 * @resume: Notifies configuration when the host restarts USB traffic,
281 * before function notifications
283 * Devices default to reporting self powered operation. Devices which rely
284 * on bus powered operation should report this in their @bind method.
286 * Before returning from @bind, various fields in the template descriptor
287 * may be overridden. These include the idVendor/idProduct/bcdDevice values
288 * normally to bind the appropriate host side driver, and the three strings
289 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
290 * meaningful device identifiers. (The strings will not be defined unless
291 * they are defined in @dev and @strings.) The correct ep0 maxpacket size
292 * is also reported, as defined by the underlying controller driver.
294 struct usb_composite_driver {
296 const struct usb_device_descriptor *dev;
297 struct usb_gadget_strings **strings;
298 enum usb_device_speed max_speed;
299 unsigned needs_serial:1;
301 int (*bind)(struct usb_composite_dev *cdev);
302 int (*unbind)(struct usb_composite_dev *);
304 void (*disconnect)(struct usb_composite_dev *);
306 /* global suspend hooks */
307 void (*suspend)(struct usb_composite_dev *);
308 void (*resume)(struct usb_composite_dev *);
309 struct usb_gadget_driver gadget_driver;
312 extern int usb_composite_probe(struct usb_composite_driver *driver);
313 extern void usb_composite_unregister(struct usb_composite_driver *driver);
314 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
318 * struct usb_composite_device - represents one composite usb gadget
319 * @gadget: read-only, abstracts the gadget's usb peripheral controller
320 * @req: used for control responses; buffer is pre-allocated
321 * @config: the currently active configuration
323 * One of these devices is allocated and initialized before the
324 * associated device driver's bind() is called.
326 * OPEN ISSUE: it appears that some WUSB devices will need to be
327 * built by combining a normal (wired) gadget with a wireless one.
328 * This revision of the gadget framework should probably try to make
329 * sure doing that won't hurt too much.
331 * One notion for how to handle Wireless USB devices involves:
332 * (a) a second gadget here, discovery mechanism TBD, but likely
333 * needing separate "register/unregister WUSB gadget" calls;
334 * (b) updates to usb_gadget to include flags "is it wireless",
335 * "is it wired", plus (presumably in a wrapper structure)
336 * bandgroup and PHY info;
337 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
338 * wireless-specific parameters like maxburst and maxsequence;
339 * (d) configurations that are specific to wireless links;
340 * (e) function drivers that understand wireless configs and will
341 * support wireless for (additional) function instances;
342 * (f) a function to support association setup (like CBAF), not
343 * necessarily requiring a wireless adapter;
344 * (g) composite device setup that can create one or more wireless
345 * configs, including appropriate association setup support;
348 struct usb_composite_dev {
349 struct usb_gadget *gadget;
350 struct usb_request *req;
352 struct usb_configuration *config;
356 unsigned int suspended:1;
357 struct usb_device_descriptor desc;
358 struct list_head configs;
359 struct usb_composite_driver *driver;
361 char *def_manufacturer;
363 /* the gadget driver won't enable the data pullup
364 * while the deactivation count is nonzero.
366 unsigned deactivations;
368 /* the composite driver won't complete the control transfer's
369 * data/status stages till delayed_status is zero.
373 /* protects deactivations and delayed_status counts*/
377 extern int usb_string_id(struct usb_composite_dev *c);
378 extern int usb_string_ids_tab(struct usb_composite_dev *c,
379 struct usb_string *str);
380 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
383 * Some systems will need runtime overrides for the product identifiers
384 * published in the device descriptor, either numbers or strings or both.
385 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
387 struct usb_composite_overwrite {
395 #define USB_GADGET_COMPOSITE_OPTIONS() \
396 static struct usb_composite_overwrite coverwrite; \
398 module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
399 MODULE_PARM_DESC(idVendor, "USB Vendor ID"); \
401 module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
402 MODULE_PARM_DESC(idProduct, "USB Product ID"); \
404 module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
405 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)"); \
407 module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
409 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string"); \
411 module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
413 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string"); \
415 module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
416 MODULE_PARM_DESC(iProduct, "USB Product string")
418 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
419 struct usb_composite_overwrite *covr);
421 /* messaging utils */
422 #define DBG(d, fmt, args...) \
423 dev_dbg(&(d)->gadget->dev , fmt , ## args)
424 #define VDBG(d, fmt, args...) \
425 dev_vdbg(&(d)->gadget->dev , fmt , ## args)
426 #define ERROR(d, fmt, args...) \
427 dev_err(&(d)->gadget->dev , fmt , ## args)
428 #define WARNING(d, fmt, args...) \
429 dev_warn(&(d)->gadget->dev , fmt , ## args)
430 #define INFO(d, fmt, args...) \
431 dev_info(&(d)->gadget->dev , fmt , ## args)
433 #endif /* __LINUX_USB_COMPOSITE_H */