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 49 struct 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 * @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. 80 * 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(). 87 * 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. 91 * 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). 97 * 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. 103 */ 104 struct usb_function { 105 const char *name; 106 struct usb_gadget_strings **strings; 107 struct usb_descriptor_header **descriptors; 108 struct usb_descriptor_header **hs_descriptors; 109 110 struct usb_configuration *config; 111 112 /* 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... 116 */ 117 118 /* configuration management: bind/unbind */ 119 int (*bind)(struct usb_configuration *, 120 struct usb_function *); 121 void (*unbind)(struct usb_configuration *, 122 struct usb_function *); 123 124 /* runtime state management */ 125 int (*set_alt)(struct usb_function *, 126 unsigned interface, unsigned alt); 127 int (*get_alt)(struct usb_function *, 128 unsigned interface); 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 *); 134 135 /* private: */ 136 /* internals */ 137 struct list_head list; 138 DECLARE_BITMAP(endpoints, 32); 139 }; 140 141 int usb_add_function(struct usb_configuration *, struct usb_function *); 142 143 int usb_function_deactivate(struct usb_function *); 144 int usb_function_activate(struct usb_function *); 145 146 int usb_interface_id(struct usb_configuration *, struct usb_function *); 147 148 /** 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 153 */ 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) 157 { 158 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH) 159 return hs; 160 return fs; 161 } 162 163 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */ 164 165 /** 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. 182 * 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. 189 * 190 * Composite devices are, by definition, ones with configurations which 191 * include more than one function. 192 * 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. 198 * 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. 205 */ 206 struct usb_configuration { 207 const char *label; 208 struct usb_gadget_strings **strings; 209 const struct usb_descriptor_header **descriptors; 210 211 /* 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... 214 */ 215 216 /* configuration management: unbind/setup */ 217 void (*unbind)(struct usb_configuration *); 218 int (*setup)(struct usb_configuration *, 219 const struct usb_ctrlrequest *); 220 221 /* fields in the config descriptor */ 222 u8 bConfigurationValue; 223 u8 iConfiguration; 224 u8 bmAttributes; 225 u8 bMaxPower; 226 227 struct usb_composite_dev *cdev; 228 229 /* private: */ 230 /* internals */ 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]; 237 }; 238 239 int usb_add_config(struct usb_composite_dev *, 240 struct usb_configuration *, 241 int (*)(struct usb_configuration *)); 242 243 /** 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 250 * will be used. 251 * @dev: Template descriptor for the device, including default device 252 * identifiers. 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 258 * this driver. 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 264 * 265 * Devices default to reporting self powered operation. Devices which rely 266 * on bus powered operation should report this in their @bind() method. 267 * 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. 275 */ 276 struct usb_composite_driver { 277 const char *name; 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; 283 284 int (*unbind)(struct usb_composite_dev *); 285 286 void (*disconnect)(struct usb_composite_dev *); 287 288 /* global suspend hooks */ 289 void (*suspend)(struct usb_composite_dev *); 290 void (*resume)(struct usb_composite_dev *); 291 }; 292 293 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); 297 298 299 /** 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 305 * 306 * One of these devices is allocated and initialized before the 307 * associated device driver's bind() is called. 308 * 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. 313 * 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; 329 * (h) more, TBD. 330 */ 331 struct usb_composite_dev { 332 struct usb_gadget *gadget; 333 struct usb_request *req; 334 unsigned bufsiz; 335 336 struct usb_configuration *config; 337 338 /* private: */ 339 /* internals */ 340 unsigned int suspended:1; 341 struct usb_device_descriptor desc; 342 struct list_head configs; 343 struct usb_composite_driver *driver; 344 u8 next_string_id; 345 u8 manufacturer_override; 346 u8 product_override; 347 u8 serial_override; 348 349 /* the gadget driver won't enable the data pullup 350 * while the deactivation count is nonzero. 351 */ 352 unsigned deactivations; 353 354 /* the composite driver won't complete the control transfer's 355 * data/status stages till delayed_status is zero. 356 */ 357 int delayed_status; 358 359 /* protects deactivations and delayed_status counts*/ 360 spinlock_t lock; 361 }; 362 363 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); 367 368 369 /* 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) 380 381 #endif /* __LINUX_USB_COMPOSITE_H */ 382