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 struct usb_configuration
;
52 * struct usb_function - describes one function of a configuration
53 * @name: For diagnostics, identifies the function.
54 * @strings: tables of strings, keyed by identifiers assigned during bind()
55 * and by language IDs provided in control requests
56 * @descriptors: Table of full (or low) speed descriptors, using interface and
57 * string identifiers assigned during @bind(). If this pointer is null,
58 * the function will not be available at full speed (or at low speed).
59 * @hs_descriptors: Table of high speed descriptors, using interface and
60 * string identifiers assigned during @bind(). If this pointer is null,
61 * the function will not be available at high speed.
62 * @config: assigned when @usb_add_function() is called; this is the
63 * configuration with which this function is associated.
64 * @bind: Before the gadget can register, all of its functions bind() to the
65 * available resources including string and interface identifiers used
66 * in interface or class descriptors; endpoints; I/O buffers; and so on.
67 * @unbind: Reverses @bind; called as a side effect of unregistering the
68 * driver which added this function.
69 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
70 * initialize usb_ep.driver data at this time (when it is used).
71 * Note that setting an interface to its current altsetting resets
72 * interface state, and that all interfaces have a disabled state.
73 * @get_alt: Returns the active altsetting. If this is not provided,
74 * then only altsetting zero is supported.
75 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons
76 * include host resetting or reconfiguring the gadget, and disconnection.
77 * @setup: Used for interface-specific control requests.
78 * @suspend: Notifies functions when the host stops sending USB traffic.
79 * @resume: Notifies functions when the host restarts USB traffic.
81 * A single USB function uses one or more interfaces, and should in most
82 * cases support operation at both full and high speeds. Each function is
83 * associated by @usb_add_function() with a one configuration; that function
84 * causes @bind() to be called so resources can be allocated as part of
85 * setting up a gadget driver. Those resources include endpoints, which
86 * should be allocated using @usb_ep_autoconfig().
88 * To support dual speed operation, a function driver provides descriptors
89 * for both high and full speed operation. Except in rare cases that don't
90 * involve bulk endpoints, each speed needs different endpoint descriptors.
92 * Function drivers choose their own strategies for managing instance data.
93 * The simplest strategy just declares it "static', which means the function
94 * can only be activated once. If the function needs to be exposed in more
95 * than one configuration at a given speed, it needs to support multiple
96 * usb_function structures (one for each configuration).
98 * A more complex strategy might encapsulate a @usb_function structure inside
99 * a driver-specific instance structure to allows multiple activations. An
100 * example of multiple activations might be a CDC ACM function that supports
101 * two or more distinct instances within the same configuration, providing
102 * several independent logical data links to a USB host.
104 struct usb_function
{
106 struct usb_gadget_strings
**strings
;
107 struct usb_descriptor_header
**descriptors
;
108 struct usb_descriptor_header
**hs_descriptors
;
110 struct usb_configuration
*config
;
112 /* REVISIT: bind() functions can be marked __init, which
113 * makes trouble for section mismatch analysis. See if
114 * we can't restructure things to avoid mismatching.
115 * Related: unbind() may kfree() but bind() won't...
118 /* configuration management: bind/unbind */
119 int (*bind
)(struct usb_configuration
*,
120 struct usb_function
*);
121 void (*unbind
)(struct usb_configuration
*,
122 struct usb_function
*);
124 /* runtime state management */
125 int (*set_alt
)(struct usb_function
*,
126 unsigned interface
, unsigned alt
);
127 int (*get_alt
)(struct usb_function
*,
129 void (*disable
)(struct usb_function
*);
130 int (*setup
)(struct usb_function
*,
131 const struct usb_ctrlrequest
*);
132 void (*suspend
)(struct usb_function
*);
133 void (*resume
)(struct usb_function
*);
137 struct list_head list
;
138 DECLARE_BITMAP(endpoints
, 32);
141 int usb_add_function(struct usb_configuration
*, struct usb_function
*);
143 int usb_function_deactivate(struct usb_function
*);
144 int usb_function_activate(struct usb_function
*);
146 int usb_interface_id(struct usb_configuration
*, struct usb_function
*);
149 * ep_choose - select descriptor endpoint at current device speed
150 * @g: gadget, connected and running at some speed
151 * @hs: descriptor to use for high speed operation
152 * @fs: descriptor to use for full or low speed operation
154 static inline struct usb_endpoint_descriptor
*
155 ep_choose(struct usb_gadget
*g
, struct usb_endpoint_descriptor
*hs
,
156 struct usb_endpoint_descriptor
*fs
)
158 if (gadget_is_dualspeed(g
) && g
->speed
== USB_SPEED_HIGH
)
163 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
166 * struct usb_configuration - represents one gadget configuration
167 * @label: For diagnostics, describes the configuration.
168 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
169 * and by language IDs provided in control requests.
170 * @descriptors: Table of descriptors preceding all function descriptors.
171 * Examples include OTG and vendor-specific descriptors.
172 * @unbind: Reverses @bind; called as a side effect of unregistering the
173 * driver which added this configuration.
174 * @setup: Used to delegate control requests that aren't handled by standard
175 * device infrastructure or directed at a specific interface.
176 * @bConfigurationValue: Copied into configuration descriptor.
177 * @iConfiguration: Copied into configuration descriptor.
178 * @bmAttributes: Copied into configuration descriptor.
179 * @bMaxPower: Copied into configuration descriptor.
180 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
181 * the device associated with this configuration.
183 * Configurations are building blocks for gadget drivers structured around
184 * function drivers. Simple USB gadgets require only one function and one
185 * configuration, and handle dual-speed hardware by always providing the same
186 * functionality. Slightly more complex gadgets may have more than one
187 * single-function configuration at a given speed; or have configurations
188 * that only work at one speed.
190 * Composite devices are, by definition, ones with configurations which
191 * include more than one function.
193 * The lifecycle of a usb_configuration includes allocation, initialization
194 * of the fields described above, and calling @usb_add_config() to set up
195 * internal data and bind it to a specific device. The configuration's
196 * @bind() method is then used to initialize all the functions and then
197 * call @usb_add_function() for them.
199 * Those functions would normally be independent of each other, but that's
200 * not mandatory. CDC WMC devices are an example where functions often
201 * depend on other functions, with some functions subsidiary to others.
202 * Such interdependency may be managed in any way, so long as all of the
203 * descriptors complete by the time the composite driver returns from
204 * its bind() routine.
206 struct usb_configuration
{
208 struct usb_gadget_strings
**strings
;
209 const struct usb_descriptor_header
**descriptors
;
211 /* REVISIT: bind() functions can be marked __init, which
212 * makes trouble for section mismatch analysis. See if
213 * we can't restructure things to avoid mismatching...
216 /* configuration management: unbind/setup */
217 void (*unbind
)(struct usb_configuration
*);
218 int (*setup
)(struct usb_configuration
*,
219 const struct usb_ctrlrequest
*);
221 /* fields in the config descriptor */
222 u8 bConfigurationValue
;
227 struct usb_composite_dev
*cdev
;
231 struct list_head list
;
232 struct list_head functions
;
233 u8 next_interface_id
;
234 unsigned highspeed
:1;
235 unsigned fullspeed
:1;
236 struct usb_function
*interface
[MAX_CONFIG_INTERFACES
];
239 int usb_add_config(struct usb_composite_dev
*,
240 struct usb_configuration
*,
241 int (*)(struct usb_configuration
*));
244 * struct usb_composite_driver - groups configurations into a gadget
245 * @name: For diagnostics, identifies the driver.
246 * @iProduct: Used as iProduct override if @dev->iProduct is not set.
247 * If NULL value of @name is taken.
248 * @iManufacturer: Used as iManufacturer override if @dev->iManufacturer is
249 * not set. If NULL a default "<system> <release> with <udc>" value
251 * @dev: Template descriptor for the device, including default device
253 * @strings: tables of strings, keyed by identifiers assigned during bind()
254 * and language IDs provided in control requests
255 * @needs_serial: set to 1 if the gadget needs userspace to provide
256 * a serial number. If one is not provided, warning will be printed.
257 * @unbind: Reverses bind; called as a side effect of unregistering
259 * @disconnect: optional driver disconnect method
260 * @suspend: Notifies when the host stops sending USB traffic,
261 * after function notifications
262 * @resume: Notifies configuration when the host restarts USB traffic,
263 * before function notifications
265 * Devices default to reporting self powered operation. Devices which rely
266 * on bus powered operation should report this in their @bind() method.
268 * Before returning from bind, various fields in the template descriptor
269 * may be overridden. These include the idVendor/idProduct/bcdDevice values
270 * normally to bind the appropriate host side driver, and the three strings
271 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
272 * meaningful device identifiers. (The strings will not be defined unless
273 * they are defined in @dev and @strings.) The correct ep0 maxpacket size
274 * is also reported, as defined by the underlying controller driver.
276 struct usb_composite_driver
{
278 const char *iProduct
;
279 const char *iManufacturer
;
280 const struct usb_device_descriptor
*dev
;
281 struct usb_gadget_strings
**strings
;
282 unsigned needs_serial
:1;
284 int (*unbind
)(struct usb_composite_dev
*);
286 void (*disconnect
)(struct usb_composite_dev
*);
288 /* global suspend hooks */
289 void (*suspend
)(struct usb_composite_dev
*);
290 void (*resume
)(struct usb_composite_dev
*);
293 extern int usb_composite_probe(struct usb_composite_driver
*driver
,
294 int (*bind
)(struct usb_composite_dev
*cdev
));
295 extern void usb_composite_unregister(struct usb_composite_driver
*driver
);
296 extern void usb_composite_setup_continue(struct usb_composite_dev
*cdev
);
300 * struct usb_composite_device - represents one composite usb gadget
301 * @gadget: read-only, abstracts the gadget's usb peripheral controller
302 * @req: used for control responses; buffer is pre-allocated
303 * @bufsiz: size of buffer pre-allocated in @req
304 * @config: the currently active configuration
306 * One of these devices is allocated and initialized before the
307 * associated device driver's bind() is called.
309 * OPEN ISSUE: it appears that some WUSB devices will need to be
310 * built by combining a normal (wired) gadget with a wireless one.
311 * This revision of the gadget framework should probably try to make
312 * sure doing that won't hurt too much.
314 * One notion for how to handle Wireless USB devices involves:
315 * (a) a second gadget here, discovery mechanism TBD, but likely
316 * needing separate "register/unregister WUSB gadget" calls;
317 * (b) updates to usb_gadget to include flags "is it wireless",
318 * "is it wired", plus (presumably in a wrapper structure)
319 * bandgroup and PHY info;
320 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
321 * wireless-specific parameters like maxburst and maxsequence;
322 * (d) configurations that are specific to wireless links;
323 * (e) function drivers that understand wireless configs and will
324 * support wireless for (additional) function instances;
325 * (f) a function to support association setup (like CBAF), not
326 * necessarily requiring a wireless adapter;
327 * (g) composite device setup that can create one or more wireless
328 * configs, including appropriate association setup support;
331 struct usb_composite_dev
{
332 struct usb_gadget
*gadget
;
333 struct usb_request
*req
;
336 struct usb_configuration
*config
;
340 unsigned int suspended
:1;
341 struct usb_device_descriptor desc
;
342 struct list_head configs
;
343 struct usb_composite_driver
*driver
;
345 u8 manufacturer_override
;
349 /* the gadget driver won't enable the data pullup
350 * while the deactivation count is nonzero.
352 unsigned deactivations
;
354 /* the composite driver won't complete the control transfer's
355 * data/status stages till delayed_status is zero.
359 /* protects deactivations and delayed_status counts*/
363 extern int usb_string_id(struct usb_composite_dev
*c
);
364 extern int usb_string_ids_tab(struct usb_composite_dev
*c
,
365 struct usb_string
*str
);
366 extern int usb_string_ids_n(struct usb_composite_dev
*c
, unsigned n
);
369 /* messaging utils */
370 #define DBG(d, fmt, args...) \
371 dev_dbg(&(d)->gadget->dev , fmt , ## args)
372 #define VDBG(d, fmt, args...) \
373 dev_vdbg(&(d)->gadget->dev , fmt , ## args)
374 #define ERROR(d, fmt, args...) \
375 dev_err(&(d)->gadget->dev , fmt , ## args)
376 #define WARNING(d, fmt, args...) \
377 dev_warn(&(d)->gadget->dev , fmt , ## args)
378 #define INFO(d, fmt, args...) \
379 dev_info(&(d)->gadget->dev , fmt , ## args)
381 #endif /* __LINUX_USB_COMPOSITE_H */