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/usb/ch9.h> 38#include <linux/usb/gadget.h> 39 40/* 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(). 46 */ 47#define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */ 48 49struct usb_configuration; 50 51/** 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 * @ss_descriptors: Table of super speed descriptors, using interface and 63 * string identifiers assigned during @bind(). If this 64 * pointer is null after initiation, the function will not 65 * be available at super speed. 66 * @config: assigned when @usb_add_function() is called; this is the 67 * configuration with which this function is associated. 68 * @bind: Before the gadget can register, all of its functions bind() to the 69 * available resources including string and interface identifiers used 70 * in interface or class descriptors; endpoints; I/O buffers; and so on. 71 * @unbind: Reverses @bind; called as a side effect of unregistering the 72 * driver which added this function. 73 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may 74 * initialize usb_ep.driver data at this time (when it is used). 75 * Note that setting an interface to its current altsetting resets 76 * interface state, and that all interfaces have a disabled state. 77 * @get_alt: Returns the active altsetting. If this is not provided, 78 * then only altsetting zero is supported. 79 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons 80 * include host resetting or reconfiguring the gadget, and disconnection. 81 * @setup: Used for interface-specific control requests. 82 * @suspend: Notifies functions when the host stops sending USB traffic. 83 * @resume: Notifies functions when the host restarts USB traffic. 84 * @get_status: Returns function status as a reply to 85 * GetStatus() request when the recepient is Interface. 86 * @func_suspend: callback to be called when 87 * SetFeature(FUNCTION_SUSPEND) is reseived 88 * 89 * A single USB function uses one or more interfaces, and should in most 90 * cases support operation at both full and high speeds. Each function is 91 * associated by @usb_add_function() with a one configuration; that function 92 * causes @bind() to be called so resources can be allocated as part of 93 * setting up a gadget driver. Those resources include endpoints, which 94 * should be allocated using @usb_ep_autoconfig(). 95 * 96 * To support dual speed operation, a function driver provides descriptors 97 * for both high and full speed operation. Except in rare cases that don't 98 * involve bulk endpoints, each speed needs different endpoint descriptors. 99 * 100 * Function drivers choose their own strategies for managing instance data. 101 * The simplest strategy just declares it "static', which means the function 102 * can only be activated once. If the function needs to be exposed in more 103 * than one configuration at a given speed, it needs to support multiple 104 * usb_function structures (one for each configuration). 105 * 106 * A more complex strategy might encapsulate a @usb_function structure inside 107 * a driver-specific instance structure to allows multiple activations. An 108 * example of multiple activations might be a CDC ACM function that supports 109 * two or more distinct instances within the same configuration, providing 110 * several independent logical data links to a USB host. 111 */ 112struct usb_function { 113 const char *name; 114 struct usb_gadget_strings **strings; 115 struct usb_descriptor_header **descriptors; 116 struct usb_descriptor_header **hs_descriptors; 117 struct usb_descriptor_header **ss_descriptors; 118 119 struct usb_configuration *config; 120 121 /* REVISIT: bind() functions can be marked __init, which 122 * makes trouble for section mismatch analysis. See if 123 * we can't restructure things to avoid mismatching. 124 * Related: unbind() may kfree() but bind() won't... 125 */ 126 127 /* configuration management: bind/unbind */ 128 int (*bind)(struct usb_configuration *, 129 struct usb_function *); 130 void (*unbind)(struct usb_configuration *, 131 struct usb_function *); 132 133 /* runtime state management */ 134 int (*set_alt)(struct usb_function *, 135 unsigned interface, unsigned alt); 136 int (*get_alt)(struct usb_function *, 137 unsigned interface); 138 void (*disable)(struct usb_function *); 139 int (*setup)(struct usb_function *, 140 const struct usb_ctrlrequest *); 141 void (*suspend)(struct usb_function *); 142 void (*resume)(struct usb_function *); 143 144 /* USB 3.0 additions */ 145 int (*get_status)(struct usb_function *); 146 int (*func_suspend)(struct usb_function *, 147 u8 suspend_opt); 148 /* private: */ 149 /* internals */ 150 struct list_head list; 151 DECLARE_BITMAP(endpoints, 32); 152}; 153 154int usb_add_function(struct usb_configuration *, struct usb_function *); 155 156int usb_function_deactivate(struct usb_function *); 157int usb_function_activate(struct usb_function *); 158 159int usb_interface_id(struct usb_configuration *, struct usb_function *); 160 161int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f, 162 struct usb_ep *_ep); 163 164#define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */ 165 166/** 167 * struct usb_configuration - represents one gadget configuration 168 * @label: For diagnostics, describes the configuration. 169 * @strings: Tables of strings, keyed by identifiers assigned during @bind() 170 * and by language IDs provided in control requests. 171 * @descriptors: Table of descriptors preceding all function descriptors. 172 * Examples include OTG and vendor-specific descriptors. 173 * @unbind: Reverses @bind; called as a side effect of unregistering the 174 * driver which added this configuration. 175 * @setup: Used to delegate control requests that aren't handled by standard 176 * device infrastructure or directed at a specific interface. 177 * @bConfigurationValue: Copied into configuration descriptor. 178 * @iConfiguration: Copied into configuration descriptor. 179 * @bmAttributes: Copied into configuration descriptor. 180 * @bMaxPower: Copied into configuration descriptor. 181 * @cdev: assigned by @usb_add_config() before calling @bind(); this is 182 * the device associated with this configuration. 183 * 184 * Configurations are building blocks for gadget drivers structured around 185 * function drivers. Simple USB gadgets require only one function and one 186 * configuration, and handle dual-speed hardware by always providing the same 187 * functionality. Slightly more complex gadgets may have more than one 188 * single-function configuration at a given speed; or have configurations 189 * that only work at one speed. 190 * 191 * Composite devices are, by definition, ones with configurations which 192 * include more than one function. 193 * 194 * The lifecycle of a usb_configuration includes allocation, initialization 195 * of the fields described above, and calling @usb_add_config() to set up 196 * internal data and bind it to a specific device. The configuration's 197 * @bind() method is then used to initialize all the functions and then 198 * call @usb_add_function() for them. 199 * 200 * Those functions would normally be independent of each other, but that's 201 * not mandatory. CDC WMC devices are an example where functions often 202 * depend on other functions, with some functions subsidiary to others. 203 * Such interdependency may be managed in any way, so long as all of the 204 * descriptors complete by the time the composite driver returns from 205 * its bind() routine. 206 */ 207struct usb_configuration { 208 const char *label; 209 struct usb_gadget_strings **strings; 210 const struct usb_descriptor_header **descriptors; 211 212 /* REVISIT: bind() functions can be marked __init, which 213 * makes trouble for section mismatch analysis. See if 214 * we can't restructure things to avoid mismatching... 215 */ 216 217 /* configuration management: unbind/setup */ 218 void (*unbind)(struct usb_configuration *); 219 int (*setup)(struct usb_configuration *, 220 const struct usb_ctrlrequest *); 221 222 /* fields in the config descriptor */ 223 u8 bConfigurationValue; 224 u8 iConfiguration; 225 u8 bmAttributes; 226 u8 bMaxPower; 227 228 struct usb_composite_dev *cdev; 229 230 /* private: */ 231 /* internals */ 232 struct list_head list; 233 struct list_head functions; 234 u8 next_interface_id; 235 unsigned superspeed:1; 236 unsigned highspeed:1; 237 unsigned fullspeed:1; 238 struct usb_function *interface[MAX_CONFIG_INTERFACES]; 239}; 240 241int usb_add_config(struct usb_composite_dev *, 242 struct usb_configuration *, 243 int (*)(struct usb_configuration *)); 244 245/** 246 * struct usb_composite_driver - groups configurations into a gadget 247 * @name: For diagnostics, identifies the driver. 248 * @iProduct: Used as iProduct override if @dev->iProduct is not set. 249 * If NULL value of @name is taken. 250 * @iManufacturer: Used as iManufacturer override if @dev->iManufacturer is 251 * not set. If NULL a default "<system> <release> with <udc>" value 252 * will be used. 253 * @dev: Template descriptor for the device, including default device 254 * identifiers. 255 * @strings: tables of strings, keyed by identifiers assigned during bind() 256 * and language IDs provided in control requests 257 * @max_speed: Highest speed the driver supports. 258 * @needs_serial: set to 1 if the gadget needs userspace to provide 259 * a serial number. If one is not provided, warning will be printed. 260 * @unbind: Reverses bind; called as a side effect of unregistering 261 * this driver. 262 * @disconnect: optional driver disconnect method 263 * @suspend: Notifies when the host stops sending USB traffic, 264 * after function notifications 265 * @resume: Notifies configuration when the host restarts USB traffic, 266 * before function notifications 267 * 268 * Devices default to reporting self powered operation. Devices which rely 269 * on bus powered operation should report this in their @bind() method. 270 * 271 * Before returning from bind, various fields in the template descriptor 272 * may be overridden. These include the idVendor/idProduct/bcdDevice values 273 * normally to bind the appropriate host side driver, and the three strings 274 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user 275 * meaningful device identifiers. (The strings will not be defined unless 276 * they are defined in @dev and @strings.) The correct ep0 maxpacket size 277 * is also reported, as defined by the underlying controller driver. 278 */ 279struct usb_composite_driver { 280 const char *name; 281 const char *iProduct; 282 const char *iManufacturer; 283 const struct usb_device_descriptor *dev; 284 struct usb_gadget_strings **strings; 285 enum usb_device_speed max_speed; 286 unsigned needs_serial:1; 287 288 int (*unbind)(struct usb_composite_dev *); 289 290 void (*disconnect)(struct usb_composite_dev *); 291 292 /* global suspend hooks */ 293 void (*suspend)(struct usb_composite_dev *); 294 void (*resume)(struct usb_composite_dev *); 295}; 296 297extern int usb_composite_probe(struct usb_composite_driver *driver, 298 int (*bind)(struct usb_composite_dev *cdev)); 299extern void usb_composite_unregister(struct usb_composite_driver *driver); 300extern void usb_composite_setup_continue(struct usb_composite_dev *cdev); 301 302 303/** 304 * struct usb_composite_device - represents one composite usb gadget 305 * @gadget: read-only, abstracts the gadget's usb peripheral controller 306 * @req: used for control responses; buffer is pre-allocated 307 * @bufsiz: size of buffer pre-allocated in @req 308 * @config: the currently active configuration 309 * 310 * One of these devices is allocated and initialized before the 311 * associated device driver's bind() is called. 312 * 313 * OPEN ISSUE: it appears that some WUSB devices will need to be 314 * built by combining a normal (wired) gadget with a wireless one. 315 * This revision of the gadget framework should probably try to make 316 * sure doing that won't hurt too much. 317 * 318 * One notion for how to handle Wireless USB devices involves: 319 * (a) a second gadget here, discovery mechanism TBD, but likely 320 * needing separate "register/unregister WUSB gadget" calls; 321 * (b) updates to usb_gadget to include flags "is it wireless", 322 * "is it wired", plus (presumably in a wrapper structure) 323 * bandgroup and PHY info; 324 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting 325 * wireless-specific parameters like maxburst and maxsequence; 326 * (d) configurations that are specific to wireless links; 327 * (e) function drivers that understand wireless configs and will 328 * support wireless for (additional) function instances; 329 * (f) a function to support association setup (like CBAF), not 330 * necessarily requiring a wireless adapter; 331 * (g) composite device setup that can create one or more wireless 332 * configs, including appropriate association setup support; 333 * (h) more, TBD. 334 */ 335struct usb_composite_dev { 336 struct usb_gadget *gadget; 337 struct usb_request *req; 338 unsigned bufsiz; 339 340 struct usb_configuration *config; 341 342 /* private: */ 343 /* internals */ 344 unsigned int suspended:1; 345 struct usb_device_descriptor desc; 346 struct list_head configs; 347 struct usb_composite_driver *driver; 348 u8 next_string_id; 349 u8 manufacturer_override; 350 u8 product_override; 351 u8 serial_override; 352 353 /* the gadget driver won't enable the data pullup 354 * while the deactivation count is nonzero. 355 */ 356 unsigned deactivations; 357 358 /* the composite driver won't complete the control transfer's 359 * data/status stages till delayed_status is zero. 360 */ 361 int delayed_status; 362 363 /* protects deactivations and delayed_status counts*/ 364 spinlock_t lock; 365}; 366 367extern int usb_string_id(struct usb_composite_dev *c); 368extern int usb_string_ids_tab(struct usb_composite_dev *c, 369 struct usb_string *str); 370extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n); 371 372 373/* messaging utils */ 374#define DBG(d, fmt, args...) \ 375 dev_dbg(&(d)->gadget->dev , fmt , ## args) 376#define VDBG(d, fmt, args...) \ 377 dev_vdbg(&(d)->gadget->dev , fmt , ## args) 378#define ERROR(d, fmt, args...) \ 379 dev_err(&(d)->gadget->dev , fmt , ## args) 380#define WARNING(d, fmt, args...) \ 381 dev_warn(&(d)->gadget->dev , fmt , ## args) 382#define INFO(d, fmt, args...) \ 383 dev_info(&(d)->gadget->dev , fmt , ## args) 384 385#endif /* __LINUX_USB_COMPOSITE_H */ 386