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/bcd.h>
38 #include <linux/version.h>
39 #include <linux/usb/ch9.h>
40 #include <linux/usb/gadget.h>
43 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
44 * wish to delay the data/status stages of the control transfer till they
45 * are ready. The control transfer will then be kept from completing till
46 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
47 * invoke usb_composite_setup_continue().
49 #define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */
51 /* big enough to hold our biggest descriptor */
52 #define USB_COMP_EP0_BUFSIZ 1024
54 struct usb_configuration;
57 * struct usb_function - describes one function of a configuration
58 * @name: For diagnostics, identifies the function.
59 * @strings: tables of strings, keyed by identifiers assigned during bind()
60 * and by language IDs provided in control requests
61 * @descriptors: Table of full (or low) speed descriptors, using interface and
62 * string identifiers assigned during @bind(). If this pointer is null,
63 * the function will not be available at full speed (or at low speed).
64 * @hs_descriptors: Table of high speed descriptors, using interface and
65 * string identifiers assigned during @bind(). If this pointer is null,
66 * the function will not be available at high speed.
67 * @ss_descriptors: Table of super speed descriptors, using interface and
68 * string identifiers assigned during @bind(). If this
69 * pointer is null after initiation, the function will not
70 * be available at super speed.
71 * @config: assigned when @usb_add_function() is called; this is the
72 * configuration with which this function is associated.
73 * @bind: Before the gadget can register, all of its functions bind() to the
74 * available resources including string and interface identifiers used
75 * in interface or class descriptors; endpoints; I/O buffers; and so on.
76 * @unbind: Reverses @bind; called as a side effect of unregistering the
77 * driver which added this function.
78 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
79 * initialize usb_ep.driver data at this time (when it is used).
80 * Note that setting an interface to its current altsetting resets
81 * interface state, and that all interfaces have a disabled state.
82 * @get_alt: Returns the active altsetting. If this is not provided,
83 * then only altsetting zero is supported.
84 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons
85 * include host resetting or reconfiguring the gadget, and disconnection.
86 * @setup: Used for interface-specific control requests.
87 * @suspend: Notifies functions when the host stops sending USB traffic.
88 * @resume: Notifies functions when the host restarts USB traffic.
89 * @get_status: Returns function status as a reply to
90 * GetStatus() request when the recepient is Interface.
91 * @func_suspend: callback to be called when
92 * SetFeature(FUNCTION_SUSPEND) is reseived
94 * A single USB function uses one or more interfaces, and should in most
95 * cases support operation at both full and high speeds. Each function is
96 * associated by @usb_add_function() with a one configuration; that function
97 * causes @bind() to be called so resources can be allocated as part of
98 * setting up a gadget driver. Those resources include endpoints, which
99 * should be allocated using @usb_ep_autoconfig().
101 * To support dual speed operation, a function driver provides descriptors
102 * for both high and full speed operation. Except in rare cases that don't
103 * involve bulk endpoints, each speed needs different endpoint descriptors.
105 * Function drivers choose their own strategies for managing instance data.
106 * The simplest strategy just declares it "static', which means the function
107 * can only be activated once. If the function needs to be exposed in more
108 * than one configuration at a given speed, it needs to support multiple
109 * usb_function structures (one for each configuration).
111 * A more complex strategy might encapsulate a @usb_function structure inside
112 * a driver-specific instance structure to allows multiple activations. An
113 * example of multiple activations might be a CDC ACM function that supports
114 * two or more distinct instances within the same configuration, providing
115 * several independent logical data links to a USB host.
117 struct usb_function {
119 struct usb_gadget_strings **strings;
120 struct usb_descriptor_header **descriptors;
121 struct usb_descriptor_header **hs_descriptors;
122 struct usb_descriptor_header **ss_descriptors;
124 struct usb_configuration *config;
126 /* REVISIT: bind() functions can be marked __init, which
127 * makes trouble for section mismatch analysis. See if
128 * we can't restructure things to avoid mismatching.
129 * Related: unbind() may kfree() but bind() won't...
132 /* configuration management: bind/unbind */
133 int (*bind)(struct usb_configuration *,
134 struct usb_function *);
135 void (*unbind)(struct usb_configuration *,
136 struct usb_function *);
138 /* runtime state management */
139 int (*set_alt)(struct usb_function *,
140 unsigned interface, unsigned alt);
141 int (*get_alt)(struct usb_function *,
143 void (*disable)(struct usb_function *);
144 int (*setup)(struct usb_function *,
145 const struct usb_ctrlrequest *);
146 void (*suspend)(struct usb_function *);
147 void (*resume)(struct usb_function *);
149 /* USB 3.0 additions */
150 int (*get_status)(struct usb_function *);
151 int (*func_suspend)(struct usb_function *,
155 struct list_head list;
156 DECLARE_BITMAP(endpoints, 32);
159 int usb_add_function(struct usb_configuration *, struct usb_function *);
161 int usb_function_deactivate(struct usb_function *);
162 int usb_function_activate(struct usb_function *);
164 int usb_interface_id(struct usb_configuration *, struct usb_function *);
166 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
169 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
172 * struct usb_configuration - represents one gadget configuration
173 * @label: For diagnostics, describes the configuration.
174 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
175 * and by language IDs provided in control requests.
176 * @descriptors: Table of descriptors preceding all function descriptors.
177 * Examples include OTG and vendor-specific descriptors.
178 * @unbind: Reverses @bind; called as a side effect of unregistering the
179 * driver which added this configuration.
180 * @setup: Used to delegate control requests that aren't handled by standard
181 * device infrastructure or directed at a specific interface.
182 * @bConfigurationValue: Copied into configuration descriptor.
183 * @iConfiguration: Copied into configuration descriptor.
184 * @bmAttributes: Copied into configuration descriptor.
185 * @bMaxPower: Copied into configuration descriptor.
186 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
187 * the device associated with this configuration.
189 * Configurations are building blocks for gadget drivers structured around
190 * function drivers. Simple USB gadgets require only one function and one
191 * configuration, and handle dual-speed hardware by always providing the same
192 * functionality. Slightly more complex gadgets may have more than one
193 * single-function configuration at a given speed; or have configurations
194 * that only work at one speed.
196 * Composite devices are, by definition, ones with configurations which
197 * include more than one function.
199 * The lifecycle of a usb_configuration includes allocation, initialization
200 * of the fields described above, and calling @usb_add_config() to set up
201 * internal data and bind it to a specific device. The configuration's
202 * @bind() method is then used to initialize all the functions and then
203 * call @usb_add_function() for them.
205 * Those functions would normally be independent of each other, but that's
206 * not mandatory. CDC WMC devices are an example where functions often
207 * depend on other functions, with some functions subsidiary to others.
208 * Such interdependency may be managed in any way, so long as all of the
209 * descriptors complete by the time the composite driver returns from
210 * its bind() routine.
212 struct usb_configuration {
214 struct usb_gadget_strings **strings;
215 const struct usb_descriptor_header **descriptors;
217 /* REVISIT: bind() functions can be marked __init, which
218 * makes trouble for section mismatch analysis. See if
219 * we can't restructure things to avoid mismatching...
222 /* configuration management: unbind/setup */
223 void (*unbind)(struct usb_configuration *);
224 int (*setup)(struct usb_configuration *,
225 const struct usb_ctrlrequest *);
227 /* fields in the config descriptor */
228 u8 bConfigurationValue;
233 struct usb_composite_dev *cdev;
237 struct list_head list;
238 struct list_head functions;
239 u8 next_interface_id;
240 unsigned superspeed:1;
241 unsigned highspeed:1;
242 unsigned fullspeed:1;
243 struct usb_function *interface[MAX_CONFIG_INTERFACES];
246 int usb_add_config(struct usb_composite_dev *,
247 struct usb_configuration *,
248 int (*)(struct usb_configuration *));
250 void usb_remove_config(struct usb_composite_dev *,
251 struct usb_configuration *);
253 /* predefined index for usb_composite_driver */
255 USB_GADGET_MANUFACTURER_IDX = 0,
256 USB_GADGET_PRODUCT_IDX,
257 USB_GADGET_SERIAL_IDX,
258 USB_GADGET_FIRST_AVAIL_IDX,
262 * struct usb_composite_driver - groups configurations into a gadget
263 * @name: For diagnostics, identifies the driver.
264 * @dev: Template descriptor for the device, including default device
266 * @strings: tables of strings, keyed by identifiers assigned during @bind
267 * and language IDs provided in control requests. Note: The first entries
268 * are predefined. The first entry that may be used is
269 * USB_GADGET_FIRST_AVAIL_IDX
270 * @max_speed: Highest speed the driver supports.
271 * @needs_serial: set to 1 if the gadget needs userspace to provide
272 * a serial number. If one is not provided, warning will be printed.
273 * @bind: (REQUIRED) Used to allocate resources that are shared across the
274 * whole device, such as string IDs, and add its configurations using
275 * @usb_add_config(). This may fail by returning a negative errno
276 * value; it should return zero on successful initialization.
277 * @unbind: Reverses @bind; called as a side effect of unregistering
279 * @disconnect: optional driver disconnect method
280 * @suspend: Notifies when the host stops sending USB traffic,
281 * after function notifications
282 * @resume: Notifies configuration when the host restarts USB traffic,
283 * before function notifications
285 * Devices default to reporting self powered operation. Devices which rely
286 * on bus powered operation should report this in their @bind method.
288 * Before returning from @bind, various fields in the template descriptor
289 * may be overridden. These include the idVendor/idProduct/bcdDevice values
290 * normally to bind the appropriate host side driver, and the three strings
291 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
292 * meaningful device identifiers. (The strings will not be defined unless
293 * they are defined in @dev and @strings.) The correct ep0 maxpacket size
294 * is also reported, as defined by the underlying controller driver.
296 struct usb_composite_driver {
298 const struct usb_device_descriptor *dev;
299 struct usb_gadget_strings **strings;
300 enum usb_device_speed max_speed;
301 unsigned needs_serial:1;
303 int (*bind)(struct usb_composite_dev *cdev);
304 int (*unbind)(struct usb_composite_dev *);
306 void (*disconnect)(struct usb_composite_dev *);
308 /* global suspend hooks */
309 void (*suspend)(struct usb_composite_dev *);
310 void (*resume)(struct usb_composite_dev *);
311 struct usb_gadget_driver gadget_driver;
314 extern int usb_composite_probe(struct usb_composite_driver *driver);
315 extern void usb_composite_unregister(struct usb_composite_driver *driver);
316 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
320 * struct usb_composite_device - represents one composite usb gadget
321 * @gadget: read-only, abstracts the gadget's usb peripheral controller
322 * @req: used for control responses; buffer is pre-allocated
323 * @config: the currently active configuration
325 * One of these devices is allocated and initialized before the
326 * associated device driver's bind() is called.
328 * OPEN ISSUE: it appears that some WUSB devices will need to be
329 * built by combining a normal (wired) gadget with a wireless one.
330 * This revision of the gadget framework should probably try to make
331 * sure doing that won't hurt too much.
333 * One notion for how to handle Wireless USB devices involves:
334 * (a) a second gadget here, discovery mechanism TBD, but likely
335 * needing separate "register/unregister WUSB gadget" calls;
336 * (b) updates to usb_gadget to include flags "is it wireless",
337 * "is it wired", plus (presumably in a wrapper structure)
338 * bandgroup and PHY info;
339 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
340 * wireless-specific parameters like maxburst and maxsequence;
341 * (d) configurations that are specific to wireless links;
342 * (e) function drivers that understand wireless configs and will
343 * support wireless for (additional) function instances;
344 * (f) a function to support association setup (like CBAF), not
345 * necessarily requiring a wireless adapter;
346 * (g) composite device setup that can create one or more wireless
347 * configs, including appropriate association setup support;
350 struct usb_composite_dev {
351 struct usb_gadget *gadget;
352 struct usb_request *req;
354 struct usb_configuration *config;
358 unsigned int suspended:1;
359 struct usb_device_descriptor desc;
360 struct list_head configs;
361 struct usb_composite_driver *driver;
363 char *def_manufacturer;
365 /* the gadget driver won't enable the data pullup
366 * while the deactivation count is nonzero.
368 unsigned deactivations;
370 /* the composite driver won't complete the control transfer's
371 * data/status stages till delayed_status is zero.
375 /* protects deactivations and delayed_status counts*/
379 extern int usb_string_id(struct usb_composite_dev *c);
380 extern int usb_string_ids_tab(struct usb_composite_dev *c,
381 struct usb_string *str);
382 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
385 * Some systems will need runtime overrides for the product identifiers
386 * published in the device descriptor, either numbers or strings or both.
387 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
389 struct usb_composite_overwrite {
397 #define USB_GADGET_COMPOSITE_OPTIONS() \
398 static struct usb_composite_overwrite coverwrite; \
400 module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
401 MODULE_PARM_DESC(idVendor, "USB Vendor ID"); \
403 module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
404 MODULE_PARM_DESC(idProduct, "USB Product ID"); \
406 module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
407 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)"); \
409 module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
411 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string"); \
413 module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
415 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string"); \
417 module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
418 MODULE_PARM_DESC(iProduct, "USB Product string")
420 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
421 struct usb_composite_overwrite *covr);
423 static inline u16 get_default_bcdDevice(void)
427 bcdDevice = bin2bcd((LINUX_VERSION_CODE >> 16 & 0xff)) << 8;
428 bcdDevice |= bin2bcd((LINUX_VERSION_CODE >> 8 & 0xff));
432 /* messaging utils */
433 #define DBG(d, fmt, args...) \
434 dev_dbg(&(d)->gadget->dev , fmt , ## args)
435 #define VDBG(d, fmt, args...) \
436 dev_vdbg(&(d)->gadget->dev , fmt , ## args)
437 #define ERROR(d, fmt, args...) \
438 dev_err(&(d)->gadget->dev , fmt , ## args)
439 #define WARNING(d, fmt, args...) \
440 dev_warn(&(d)->gadget->dev , fmt , ## args)
441 #define INFO(d, fmt, args...) \
442 dev_info(&(d)->gadget->dev , fmt , ## args)
444 #endif /* __LINUX_USB_COMPOSITE_H */