1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * composite.h -- framework for usb gadgets which are composite devices 4 * 5 * Copyright (C) 2006-2008 David Brownell 6 */ 7 8#ifndef __LINUX_USB_COMPOSITE_H 9#define __LINUX_USB_COMPOSITE_H 10 11/* 12 * This framework is an optional layer on top of the USB Gadget interface, 13 * making it easier to build (a) Composite devices, supporting multiple 14 * functions within any single configuration, and (b) Multi-configuration 15 * devices, also supporting multiple functions but without necessarily 16 * having more than one function per configuration. 17 * 18 * Example: a device with a single configuration supporting both network 19 * link and mass storage functions is a composite device. Those functions 20 * might alternatively be packaged in individual configurations, but in 21 * the composite model the host can use both functions at the same time. 22 */ 23 24#include <common.h> 25#include <linux/usb/ch9.h> 26#include <linux/usb/gadget.h> 27#include <linux/bitmap.h> 28 29/* 30 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they 31 * wish to delay the data/status stages of the control transfer till they 32 * are ready. The control transfer will then be kept from completing till 33 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS 34 * invoke usb_composite_setup_continue(). 35 */ 36#define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */ 37 38struct usb_configuration; 39 40/** 41 * struct usb_os_desc_ext_prop - describes one "Extended Property" 42 * @entry: used to keep a list of extended properties 43 * @type: Extended Property type 44 * @name_len: Extended Property unicode name length, including terminating '\0' 45 * @name: Extended Property name 46 * @data_len: Length of Extended Property blob (for unicode store double len) 47 * @data: Extended Property blob 48 */ 49struct usb_os_desc_ext_prop { 50 struct list_head entry; 51 u8 type; 52 int name_len; 53 char *name; 54 int data_len; 55 char *data; 56}; 57 58/** 59 * struct usb_os_desc - describes OS descriptors associated with one interface 60 * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID" 61 * @ext_prop: Extended Properties list 62 * @ext_prop_len: Total length of Extended Properties blobs 63 * @ext_prop_count: Number of Extended Properties 64 */ 65struct usb_os_desc { 66 char *ext_compat_id; 67 struct list_head ext_prop; 68 int ext_prop_len; 69 int ext_prop_count; 70}; 71 72/** 73 * struct usb_os_desc_table - describes OS descriptors associated with one 74 * interface of a usb_function 75 * @if_id: Interface id 76 * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the 77 * interface 78 * 79 * Each interface can have at most one "Extended Compatibility ID" and a 80 * number of "Extended Properties". 81 */ 82struct usb_os_desc_table { 83 int if_id; 84 struct usb_os_desc *os_desc; 85}; 86 87/** 88 * struct usb_function - describes one function of a configuration 89 * @name: For diagnostics, identifies the function. 90 * @strings: tables of strings, keyed by identifiers assigned during bind() 91 * and by language IDs provided in control requests 92 * @descriptors: Table of full (or low) speed descriptors, using interface and 93 * string identifiers assigned during @bind(). If this pointer is null, 94 * the function will not be available at full speed (or at low speed). 95 * @hs_descriptors: Table of high speed descriptors, using interface and 96 * string identifiers assigned during @bind(). If this pointer is null, 97 * the function will not be available at high speed. 98 * @config: assigned when @usb_add_function() is called; this is the 99 * configuration with which this function is associated. 100 * @os_desc_table: Table of (interface id, os descriptors) pairs. The function 101 * can expose more than one interface. If an interface is a member of 102 * an IAD, only the first interface of IAD has its entry in the table. 103 * @os_desc_n: Number of entries in os_desc_table 104 * @bind: Before the gadget can register, all of its functions bind() to the 105 * available resources including string and interface identifiers used 106 * in interface or class descriptors; endpoints; I/O buffers; and so on. 107 * @unbind: Reverses @bind; called as a side effect of unregistering the 108 * driver which added this function. 109 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may 110 * initialize usb_ep.driver data at this time (when it is used). 111 * Note that setting an interface to its current altsetting resets 112 * interface state, and that all interfaces have a disabled state. 113 * @get_alt: Returns the active altsetting. If this is not provided, 114 * then only altsetting zero is supported. 115 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons 116 * include host resetting or reconfiguring the gadget, and disconnection. 117 * @setup: Used for interface-specific control requests. 118 * @suspend: Notifies functions when the host stops sending USB traffic. 119 * @resume: Notifies functions when the host restarts USB traffic. 120 * 121 * A single USB function uses one or more interfaces, and should in most 122 * cases support operation at both full and high speeds. Each function is 123 * associated by @usb_add_function() with a one configuration; that function 124 * causes @bind() to be called so resources can be allocated as part of 125 * setting up a gadget driver. Those resources include endpoints, which 126 * should be allocated using @usb_ep_autoconfig(). 127 * 128 * To support dual speed operation, a function driver provides descriptors 129 * for both high and full speed operation. Except in rare cases that don't 130 * involve bulk endpoints, each speed needs different endpoint descriptors. 131 * 132 * Function drivers choose their own strategies for managing instance data. 133 * The simplest strategy just declares it "static', which means the function 134 * can only be activated once. If the function needs to be exposed in more 135 * than one configuration at a given speed, it needs to support multiple 136 * usb_function structures (one for each configuration). 137 * 138 * A more complex strategy might encapsulate a @usb_function structure inside 139 * a driver-specific instance structure to allows multiple activations. An 140 * example of multiple activations might be a CDC ACM function that supports 141 * two or more distinct instances within the same configuration, providing 142 * several independent logical data links to a USB host. 143 */ 144struct usb_function { 145 const char *name; 146 struct usb_gadget_strings **strings; 147 struct usb_descriptor_header **descriptors; 148 struct usb_descriptor_header **hs_descriptors; 149 struct usb_descriptor_header **ss_descriptors; 150 151 struct usb_configuration *config; 152 153 struct usb_os_desc_table *os_desc_table; 154 unsigned os_desc_n; 155 156 /* REVISIT: bind() functions can be marked __init, which 157 * makes trouble for section mismatch analysis. See if 158 * we can't restructure things to avoid mismatching. 159 * Related: unbind() may kfree() but bind() won't... 160 */ 161 162 /* configuration management: bind/unbind */ 163 int (*bind)(struct usb_configuration *, 164 struct usb_function *); 165 void (*unbind)(struct usb_configuration *, 166 struct usb_function *); 167 168 /* runtime state management */ 169 int (*set_alt)(struct usb_function *, 170 unsigned interface, unsigned alt); 171 int (*get_alt)(struct usb_function *, 172 unsigned interface); 173 void (*disable)(struct usb_function *); 174 int (*setup)(struct usb_function *, 175 const struct usb_ctrlrequest *); 176 void (*suspend)(struct usb_function *); 177 void (*resume)(struct usb_function *); 178 179 /* private: */ 180 /* internals */ 181 struct list_head list; 182 DECLARE_BITMAP(endpoints, 32); 183}; 184 185int usb_add_function(struct usb_configuration *, struct usb_function *); 186 187int usb_function_deactivate(struct usb_function *); 188int usb_function_activate(struct usb_function *); 189 190int usb_interface_id(struct usb_configuration *, struct usb_function *); 191 192/** 193 * ep_choose - select descriptor endpoint at current device speed 194 * @g: gadget, connected and running at some speed 195 * @hs: descriptor to use for high speed operation 196 * @fs: descriptor to use for full or low speed operation 197 */ 198static inline struct usb_endpoint_descriptor * 199ep_choose(struct usb_gadget *g, struct usb_endpoint_descriptor *hs, 200 struct usb_endpoint_descriptor *fs) 201{ 202 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH) 203 return hs; 204 return fs; 205} 206 207#define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */ 208 209/** 210 * struct usb_configuration - represents one gadget configuration 211 * @label: For diagnostics, describes the configuration. 212 * @strings: Tables of strings, keyed by identifiers assigned during @bind() 213 * and by language IDs provided in control requests. 214 * @descriptors: Table of descriptors preceding all function descriptors. 215 * Examples include OTG and vendor-specific descriptors. 216 * @bind: Called from @usb_add_config() to allocate resources unique to this 217 * configuration and to call @usb_add_function() for each function used. 218 * @unbind: Reverses @bind; called as a side effect of unregistering the 219 * driver which added this configuration. 220 * @setup: Used to delegate control requests that aren't handled by standard 221 * device infrastructure or directed at a specific interface. 222 * @bConfigurationValue: Copied into configuration descriptor. 223 * @iConfiguration: Copied into configuration descriptor. 224 * @bmAttributes: Copied into configuration descriptor. 225 * @bMaxPower: Copied into configuration descriptor. 226 * @cdev: assigned by @usb_add_config() before calling @bind(); this is 227 * the device associated with this configuration. 228 * 229 * Configurations are building blocks for gadget drivers structured around 230 * function drivers. Simple USB gadgets require only one function and one 231 * configuration, and handle dual-speed hardware by always providing the same 232 * functionality. Slightly more complex gadgets may have more than one 233 * single-function configuration at a given speed; or have configurations 234 * that only work at one speed. 235 * 236 * Composite devices are, by definition, ones with configurations which 237 * include more than one function. 238 * 239 * The lifecycle of a usb_configuration includes allocation, initialization 240 * of the fields described above, and calling @usb_add_config() to set up 241 * internal data and bind it to a specific device. The configuration's 242 * @bind() method is then used to initialize all the functions and then 243 * call @usb_add_function() for them. 244 * 245 * Those functions would normally be independant of each other, but that's 246 * not mandatory. CDC WMC devices are an example where functions often 247 * depend on other functions, with some functions subsidiary to others. 248 * Such interdependency may be managed in any way, so long as all of the 249 * descriptors complete by the time the composite driver returns from 250 * its bind() routine. 251 */ 252struct usb_configuration { 253 const char *label; 254 struct usb_gadget_strings **strings; 255 const struct usb_descriptor_header **descriptors; 256 257 /* REVISIT: bind() functions can be marked __init, which 258 * makes trouble for section mismatch analysis. See if 259 * we can't restructure things to avoid mismatching... 260 */ 261 262 /* configuration management: bind/unbind */ 263 int (*bind)(struct usb_configuration *); 264 void (*unbind)(struct usb_configuration *); 265 int (*setup)(struct usb_configuration *, 266 const struct usb_ctrlrequest *); 267 268 /* fields in the config descriptor */ 269 u8 bConfigurationValue; 270 u8 iConfiguration; 271 u8 bmAttributes; 272 u8 bMaxPower; 273 274 struct usb_composite_dev *cdev; 275 276 /* private: */ 277 /* internals */ 278 struct list_head list; 279 struct list_head functions; 280 u8 next_interface_id; 281 unsigned highspeed:1; 282 unsigned fullspeed:1; 283 unsigned superspeed:1; 284 struct usb_function *interface[MAX_CONFIG_INTERFACES]; 285}; 286 287int usb_add_config(struct usb_composite_dev *, 288 struct usb_configuration *); 289 290/** 291 * struct usb_composite_driver - groups configurations into a gadget 292 * @name: For diagnostics, identifies the driver. 293 * @dev: Template descriptor for the device, including default device 294 * identifiers. 295 * @strings: tables of strings, keyed by identifiers assigned during bind() 296 * and language IDs provided in control requests 297 * @max_speed: Highest speed the driver supports. 298 * @bind: (REQUIRED) Used to allocate resources that are shared across the 299 * whole device, such as string IDs, and add its configurations using 300 * @usb_add_config(). This may fail by returning a negative errno 301 * value; it should return zero on successful initialization. 302 * @unbind: Reverses @bind(); called as a side effect of unregistering 303 * this driver. 304 * @disconnect: optional driver disconnect method 305 * @suspend: Notifies when the host stops sending USB traffic, 306 * after function notifications 307 * @resume: Notifies configuration when the host restarts USB traffic, 308 * before function notifications 309 * 310 * Devices default to reporting self powered operation. Devices which rely 311 * on bus powered operation should report this in their @bind() method. 312 * 313 * Before returning from @bind, various fields in the template descriptor 314 * may be overridden. These include the idVendor/idProduct/bcdDevice values 315 * normally to bind the appropriate host side driver, and the three strings 316 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user 317 * meaningful device identifiers. (The strings will not be defined unless 318 * they are defined in @dev and @strings.) The correct ep0 maxpacket size 319 * is also reported, as defined by the underlying controller driver. 320 */ 321struct usb_composite_driver { 322 const char *name; 323 const struct usb_device_descriptor *dev; 324 struct usb_gadget_strings **strings; 325 enum usb_device_speed max_speed; 326 327 /* REVISIT: bind() functions can be marked __init, which 328 * makes trouble for section mismatch analysis. See if 329 * we can't restructure things to avoid mismatching... 330 */ 331 332 int (*bind)(struct usb_composite_dev *); 333 int (*unbind)(struct usb_composite_dev *); 334 335 void (*disconnect)(struct usb_composite_dev *); 336 337 /* global suspend hooks */ 338 void (*suspend)(struct usb_composite_dev *); 339 void (*resume)(struct usb_composite_dev *); 340}; 341 342extern int usb_composite_register(struct usb_composite_driver *); 343extern void usb_composite_unregister(struct usb_composite_driver *); 344 345#define OS_STRING_QW_SIGN_LEN 14 346#define OS_STRING_IDX 0xEE 347 348/** 349 * struct usb_composite_device - represents one composite usb gadget 350 * @gadget: read-only, abstracts the gadget's usb peripheral controller 351 * @req: used for control responses; buffer is pre-allocated 352 * @bufsiz: size of buffer pre-allocated in @req 353 * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated 354 * @config: the currently active configuration 355 * @qw_sign: qwSignature part of the OS string 356 * @b_vendor_code: bMS_VendorCode part of the OS string 357 * @use_os_string: false by default, interested gadgets set it 358 * @os_desc_config: the configuration to be used with OS descriptors 359 * 360 * One of these devices is allocated and initialized before the 361 * associated device driver's bind() is called. 362 * 363 * OPEN ISSUE: it appears that some WUSB devices will need to be 364 * built by combining a normal (wired) gadget with a wireless one. 365 * This revision of the gadget framework should probably try to make 366 * sure doing that won't hurt too much. 367 * 368 * One notion for how to handle Wireless USB devices involves: 369 * (a) a second gadget here, discovery mechanism TBD, but likely 370 * needing separate "register/unregister WUSB gadget" calls; 371 * (b) updates to usb_gadget to include flags "is it wireless", 372 * "is it wired", plus (presumably in a wrapper structure) 373 * bandgroup and PHY info; 374 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting 375 * wireless-specific parameters like maxburst and maxsequence; 376 * (d) configurations that are specific to wireless links; 377 * (e) function drivers that understand wireless configs and will 378 * support wireless for (additional) function instances; 379 * (f) a function to support association setup (like CBAF), not 380 * necessarily requiring a wireless adapter; 381 * (g) composite device setup that can create one or more wireless 382 * configs, including appropriate association setup support; 383 * (h) more, TBD. 384 */ 385struct usb_composite_dev { 386 struct usb_gadget *gadget; 387 struct usb_request *req; 388 unsigned bufsiz; 389 390 struct usb_configuration *config; 391 392 /* OS String is a custom (yet popular) extension to the USB standard. */ 393 u8 qw_sign[OS_STRING_QW_SIGN_LEN]; 394 u8 b_vendor_code; 395 struct usb_configuration *os_desc_config; 396 unsigned int use_os_string:1; 397 398 /* private: */ 399 /* internals */ 400 unsigned int suspended:1; 401 struct usb_device_descriptor __aligned(CONFIG_SYS_CACHELINE_SIZE) desc; 402 struct list_head configs; 403 struct usb_composite_driver *driver; 404 u8 next_string_id; 405 406 /* the gadget driver won't enable the data pullup 407 * while the deactivation count is nonzero. 408 */ 409 unsigned deactivations; 410}; 411 412extern int usb_string_id(struct usb_composite_dev *c); 413extern int usb_string_ids_tab(struct usb_composite_dev *c, 414 struct usb_string *str); 415extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n); 416 417#endif /* __LINUX_USB_COMPOSITE_H */ 418