1 /* 2 * <linux/usb/gadget.h> 3 * 4 * We call the USB code inside a Linux-based peripheral device a "gadget" 5 * driver, except for the hardware-specific bus glue. One USB host can 6 * master many USB gadgets, but the gadgets are only slaved to one host. 7 * 8 * 9 * (C) Copyright 2002-2004 by David Brownell 10 * All Rights Reserved. 11 * 12 * This software is licensed under the GNU GPL version 2. 13 */ 14 15 #ifndef __LINUX_USB_GADGET_H 16 #define __LINUX_USB_GADGET_H 17 18 #include <linux/device.h> 19 #include <linux/errno.h> 20 #include <linux/init.h> 21 #include <linux/list.h> 22 #include <linux/slab.h> 23 #include <linux/scatterlist.h> 24 #include <linux/types.h> 25 #include <linux/workqueue.h> 26 #include <linux/usb/ch9.h> 27 28 #define UDC_TRACE_STR_MAX 512 29 30 struct usb_ep; 31 32 /** 33 * struct usb_request - describes one i/o request 34 * @buf: Buffer used for data. Always provide this; some controllers 35 * only use PIO, or don't use DMA for some endpoints. 36 * @dma: DMA address corresponding to 'buf'. If you don't set this 37 * field, and the usb controller needs one, it is responsible 38 * for mapping and unmapping the buffer. 39 * @sg: a scatterlist for SG-capable controllers. 40 * @num_sgs: number of SG entries 41 * @num_mapped_sgs: number of SG entries mapped to DMA (internal) 42 * @length: Length of that data 43 * @stream_id: The stream id, when USB3.0 bulk streams are being used 44 * @no_interrupt: If true, hints that no completion irq is needed. 45 * Helpful sometimes with deep request queues that are handled 46 * directly by DMA controllers. 47 * @zero: If true, when writing data, makes the last packet be "short" 48 * by adding a zero length packet as needed; 49 * @short_not_ok: When reading data, makes short packets be 50 * treated as errors (queue stops advancing till cleanup). 51 * @complete: Function called when request completes, so this request and 52 * its buffer may be re-used. The function will always be called with 53 * interrupts disabled, and it must not sleep. 54 * Reads terminate with a short packet, or when the buffer fills, 55 * whichever comes first. When writes terminate, some data bytes 56 * will usually still be in flight (often in a hardware fifo). 57 * Errors (for reads or writes) stop the queue from advancing 58 * until the completion function returns, so that any transfers 59 * invalidated by the error may first be dequeued. 60 * @context: For use by the completion callback 61 * @list: For use by the gadget driver. 62 * @status: Reports completion code, zero or a negative errno. 63 * Normally, faults block the transfer queue from advancing until 64 * the completion callback returns. 65 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 66 * or when the driver disabled the endpoint. 67 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 68 * transfers) this may be less than the requested length. If the 69 * short_not_ok flag is set, short reads are treated as errors 70 * even when status otherwise indicates successful completion. 71 * Note that for writes (IN transfers) some data bytes may still 72 * reside in a device-side FIFO when the request is reported as 73 * complete. 74 * 75 * These are allocated/freed through the endpoint they're used with. The 76 * hardware's driver can add extra per-request data to the memory it returns, 77 * which often avoids separate memory allocations (potential failures), 78 * later when the request is queued. 79 * 80 * Request flags affect request handling, such as whether a zero length 81 * packet is written (the "zero" flag), whether a short read should be 82 * treated as an error (blocking request queue advance, the "short_not_ok" 83 * flag), or hinting that an interrupt is not required (the "no_interrupt" 84 * flag, for use with deep request queues). 85 * 86 * Bulk endpoints can use any size buffers, and can also be used for interrupt 87 * transfers. interrupt-only endpoints can be much less functional. 88 * 89 * NOTE: this is analogous to 'struct urb' on the host side, except that 90 * it's thinner and promotes more pre-allocation. 91 */ 92 93 struct usb_request { 94 void *buf; 95 unsigned length; 96 dma_addr_t dma; 97 98 struct scatterlist *sg; 99 unsigned num_sgs; 100 unsigned num_mapped_sgs; 101 102 unsigned stream_id:16; 103 unsigned no_interrupt:1; 104 unsigned zero:1; 105 unsigned short_not_ok:1; 106 107 void (*complete)(struct usb_ep *ep, 108 struct usb_request *req); 109 void *context; 110 struct list_head list; 111 112 int status; 113 unsigned actual; 114 }; 115 116 /*-------------------------------------------------------------------------*/ 117 118 /* endpoint-specific parts of the api to the usb controller hardware. 119 * unlike the urb model, (de)multiplexing layers are not required. 120 * (so this api could slash overhead if used on the host side...) 121 * 122 * note that device side usb controllers commonly differ in how many 123 * endpoints they support, as well as their capabilities. 124 */ 125 struct usb_ep_ops { 126 int (*enable) (struct usb_ep *ep, 127 const struct usb_endpoint_descriptor *desc); 128 int (*disable) (struct usb_ep *ep); 129 130 struct usb_request *(*alloc_request) (struct usb_ep *ep, 131 gfp_t gfp_flags); 132 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 133 134 int (*queue) (struct usb_ep *ep, struct usb_request *req, 135 gfp_t gfp_flags); 136 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 137 138 int (*set_halt) (struct usb_ep *ep, int value); 139 int (*set_wedge) (struct usb_ep *ep); 140 141 int (*fifo_status) (struct usb_ep *ep); 142 void (*fifo_flush) (struct usb_ep *ep); 143 }; 144 145 /** 146 * struct usb_ep_caps - endpoint capabilities description 147 * @type_control:Endpoint supports control type (reserved for ep0). 148 * @type_iso:Endpoint supports isochronous transfers. 149 * @type_bulk:Endpoint supports bulk transfers. 150 * @type_int:Endpoint supports interrupt transfers. 151 * @dir_in:Endpoint supports IN direction. 152 * @dir_out:Endpoint supports OUT direction. 153 */ 154 struct usb_ep_caps { 155 unsigned type_control:1; 156 unsigned type_iso:1; 157 unsigned type_bulk:1; 158 unsigned type_int:1; 159 unsigned dir_in:1; 160 unsigned dir_out:1; 161 }; 162 163 #define USB_EP_CAPS_TYPE_CONTROL 0x01 164 #define USB_EP_CAPS_TYPE_ISO 0x02 165 #define USB_EP_CAPS_TYPE_BULK 0x04 166 #define USB_EP_CAPS_TYPE_INT 0x08 167 #define USB_EP_CAPS_TYPE_ALL \ 168 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 169 #define USB_EP_CAPS_DIR_IN 0x01 170 #define USB_EP_CAPS_DIR_OUT 0x02 171 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 172 173 #define USB_EP_CAPS(_type, _dir) \ 174 { \ 175 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 176 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 177 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 178 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 179 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 180 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 181 } 182 183 /** 184 * struct usb_ep - device side representation of USB endpoint 185 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 186 * @ops: Function pointers used to access hardware-specific operations. 187 * @ep_list:the gadget's ep_list holds all of its endpoints 188 * @caps:The structure describing types and directions supported by endoint. 189 * @maxpacket:The maximum packet size used on this endpoint. The initial 190 * value can sometimes be reduced (hardware allowing), according to 191 * the endpoint descriptor used to configure the endpoint. 192 * @maxpacket_limit:The maximum packet size value which can be handled by this 193 * endpoint. It's set once by UDC driver when endpoint is initialized, and 194 * should not be changed. Should not be confused with maxpacket. 195 * @max_streams: The maximum number of streams supported 196 * by this EP (0 - 16, actual number is 2^n) 197 * @mult: multiplier, 'mult' value for SS Isoc EPs 198 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 199 * @driver_data:for use by the gadget driver. 200 * @address: used to identify the endpoint when finding descriptor that 201 * matches connection speed 202 * @desc: endpoint descriptor. This pointer is set before the endpoint is 203 * enabled and remains valid until the endpoint is disabled. 204 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 205 * descriptor that is used to configure the endpoint 206 * 207 * the bus controller driver lists all the general purpose endpoints in 208 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 209 * and is accessed only in response to a driver setup() callback. 210 */ 211 212 struct usb_ep { 213 void *driver_data; 214 215 const char *name; 216 const struct usb_ep_ops *ops; 217 struct list_head ep_list; 218 struct usb_ep_caps caps; 219 bool claimed; 220 bool enabled; 221 unsigned maxpacket:16; 222 unsigned maxpacket_limit:16; 223 unsigned max_streams:16; 224 unsigned mult:2; 225 unsigned maxburst:5; 226 u8 address; 227 const struct usb_endpoint_descriptor *desc; 228 const struct usb_ss_ep_comp_descriptor *comp_desc; 229 }; 230 231 /*-------------------------------------------------------------------------*/ 232 233 #if IS_ENABLED(CONFIG_USB_GADGET) 234 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); 235 int usb_ep_enable(struct usb_ep *ep); 236 int usb_ep_disable(struct usb_ep *ep); 237 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); 238 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); 239 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); 240 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); 241 int usb_ep_set_halt(struct usb_ep *ep); 242 int usb_ep_clear_halt(struct usb_ep *ep); 243 int usb_ep_set_wedge(struct usb_ep *ep); 244 int usb_ep_fifo_status(struct usb_ep *ep); 245 void usb_ep_fifo_flush(struct usb_ep *ep); 246 #else 247 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 248 unsigned maxpacket_limit) 249 { } 250 static inline int usb_ep_enable(struct usb_ep *ep) 251 { return 0; } 252 static inline int usb_ep_disable(struct usb_ep *ep) 253 { return 0; } 254 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 255 gfp_t gfp_flags) 256 { return NULL; } 257 static inline void usb_ep_free_request(struct usb_ep *ep, 258 struct usb_request *req) 259 { } 260 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, 261 gfp_t gfp_flags) 262 { return 0; } 263 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 264 { return 0; } 265 static inline int usb_ep_set_halt(struct usb_ep *ep) 266 { return 0; } 267 static inline int usb_ep_clear_halt(struct usb_ep *ep) 268 { return 0; } 269 static inline int usb_ep_set_wedge(struct usb_ep *ep) 270 { return 0; } 271 static inline int usb_ep_fifo_status(struct usb_ep *ep) 272 { return 0; } 273 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 274 { } 275 #endif /* USB_GADGET */ 276 277 /*-------------------------------------------------------------------------*/ 278 279 struct usb_dcd_config_params { 280 __u8 bU1devExitLat; /* U1 Device exit Latency */ 281 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 282 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 283 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 284 }; 285 286 287 struct usb_gadget; 288 struct usb_gadget_driver; 289 struct usb_udc; 290 291 /* the rest of the api to the controller hardware: device operations, 292 * which don't involve endpoints (or i/o). 293 */ 294 struct usb_gadget_ops { 295 int (*get_frame)(struct usb_gadget *); 296 int (*wakeup)(struct usb_gadget *); 297 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 298 int (*vbus_session) (struct usb_gadget *, int is_active); 299 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 300 int (*pullup) (struct usb_gadget *, int is_on); 301 int (*ioctl)(struct usb_gadget *, 302 unsigned code, unsigned long param); 303 void (*get_config_params)(struct usb_dcd_config_params *); 304 int (*udc_start)(struct usb_gadget *, 305 struct usb_gadget_driver *); 306 int (*udc_stop)(struct usb_gadget *); 307 struct usb_ep *(*match_ep)(struct usb_gadget *, 308 struct usb_endpoint_descriptor *, 309 struct usb_ss_ep_comp_descriptor *); 310 }; 311 312 /** 313 * struct usb_gadget - represents a usb slave device 314 * @work: (internal use) Workqueue to be used for sysfs_notify() 315 * @udc: struct usb_udc pointer for this gadget 316 * @ops: Function pointers used to access hardware-specific operations. 317 * @ep0: Endpoint zero, used when reading or writing responses to 318 * driver setup() requests 319 * @ep_list: List of other endpoints supported by the device. 320 * @speed: Speed of current connection to USB host. 321 * @max_speed: Maximal speed the UDC can handle. UDC must support this 322 * and all slower speeds. 323 * @state: the state we are now (attached, suspended, configured, etc) 324 * @name: Identifies the controller hardware type. Used in diagnostics 325 * and sometimes configuration. 326 * @dev: Driver model state for this abstract device. 327 * @out_epnum: last used out ep number 328 * @in_epnum: last used in ep number 329 * @mA: last set mA value 330 * @otg_caps: OTG capabilities of this gadget. 331 * @sg_supported: true if we can handle scatter-gather 332 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 333 * gadget driver must provide a USB OTG descriptor. 334 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 335 * is in the Mini-AB jack, and HNP has been used to switch roles 336 * so that the "A" device currently acts as A-Peripheral, not A-Host. 337 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 338 * supports HNP at this port. 339 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 340 * only supports HNP on a different root port. 341 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 342 * enabled HNP support. 343 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 344 * in peripheral mode can support HNP polling. 345 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 346 * or B-Peripheral wants to take host role. 347 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 348 * MaxPacketSize. 349 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 350 * u_ether.c to improve performance. 351 * @is_selfpowered: if the gadget is self-powered. 352 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 353 * be connected. 354 * @connected: True if gadget is connected. 355 * 356 * Gadgets have a mostly-portable "gadget driver" implementing device 357 * functions, handling all usb configurations and interfaces. Gadget 358 * drivers talk to hardware-specific code indirectly, through ops vectors. 359 * That insulates the gadget driver from hardware details, and packages 360 * the hardware endpoints through generic i/o queues. The "usb_gadget" 361 * and "usb_ep" interfaces provide that insulation from the hardware. 362 * 363 * Except for the driver data, all fields in this structure are 364 * read-only to the gadget driver. That driver data is part of the 365 * "driver model" infrastructure in 2.6 (and later) kernels, and for 366 * earlier systems is grouped in a similar structure that's not known 367 * to the rest of the kernel. 368 * 369 * Values of the three OTG device feature flags are updated before the 370 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 371 * driver suspend() calls. They are valid only when is_otg, and when the 372 * device is acting as a B-Peripheral (so is_a_peripheral is false). 373 */ 374 struct usb_gadget { 375 struct work_struct work; 376 struct usb_udc *udc; 377 /* readonly to gadget driver */ 378 const struct usb_gadget_ops *ops; 379 struct usb_ep *ep0; 380 struct list_head ep_list; /* of usb_ep */ 381 enum usb_device_speed speed; 382 enum usb_device_speed max_speed; 383 enum usb_device_state state; 384 const char *name; 385 struct device dev; 386 unsigned out_epnum; 387 unsigned in_epnum; 388 unsigned mA; 389 struct usb_otg_caps *otg_caps; 390 391 unsigned sg_supported:1; 392 unsigned is_otg:1; 393 unsigned is_a_peripheral:1; 394 unsigned b_hnp_enable:1; 395 unsigned a_hnp_support:1; 396 unsigned a_alt_hnp_support:1; 397 unsigned hnp_polling_support:1; 398 unsigned host_request_flag:1; 399 unsigned quirk_ep_out_aligned_size:1; 400 unsigned quirk_altset_not_supp:1; 401 unsigned quirk_stall_not_supp:1; 402 unsigned quirk_zlp_not_supp:1; 403 unsigned quirk_avoids_skb_reserve:1; 404 unsigned is_selfpowered:1; 405 unsigned deactivated:1; 406 unsigned connected:1; 407 }; 408 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 409 410 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 411 { dev_set_drvdata(&gadget->dev, data); } 412 static inline void *get_gadget_data(struct usb_gadget *gadget) 413 { return dev_get_drvdata(&gadget->dev); } 414 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 415 { 416 return container_of(dev, struct usb_gadget, dev); 417 } 418 419 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 420 #define gadget_for_each_ep(tmp, gadget) \ 421 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 422 423 /** 424 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 425 * @ep: the endpoint whose maxpacketsize is used to align @len 426 * @len: buffer size's length to align to @ep's maxpacketsize 427 * 428 * This helper is used to align buffer's size to an ep's maxpacketsize. 429 */ 430 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 431 { 432 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff; 433 434 return round_up(len, max_packet_size); 435 } 436 437 /** 438 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 439 * requires quirk_ep_out_aligned_size, otherwise returns len. 440 * @g: controller to check for quirk 441 * @ep: the endpoint whose maxpacketsize is used to align @len 442 * @len: buffer size's length to align to @ep's maxpacketsize 443 * 444 * This helper is used in case it's required for any reason to check and maybe 445 * align buffer's size to an ep's maxpacketsize. 446 */ 447 static inline size_t 448 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 449 { 450 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 451 } 452 453 /** 454 * gadget_is_altset_supported - return true iff the hardware supports 455 * altsettings 456 * @g: controller to check for quirk 457 */ 458 static inline int gadget_is_altset_supported(struct usb_gadget *g) 459 { 460 return !g->quirk_altset_not_supp; 461 } 462 463 /** 464 * gadget_is_stall_supported - return true iff the hardware supports stalling 465 * @g: controller to check for quirk 466 */ 467 static inline int gadget_is_stall_supported(struct usb_gadget *g) 468 { 469 return !g->quirk_stall_not_supp; 470 } 471 472 /** 473 * gadget_is_zlp_supported - return true iff the hardware supports zlp 474 * @g: controller to check for quirk 475 */ 476 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 477 { 478 return !g->quirk_zlp_not_supp; 479 } 480 481 /** 482 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 483 * skb_reserve to improve performance. 484 * @g: controller to check for quirk 485 */ 486 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 487 { 488 return g->quirk_avoids_skb_reserve; 489 } 490 491 /** 492 * gadget_is_dualspeed - return true iff the hardware handles high speed 493 * @g: controller that might support both high and full speeds 494 */ 495 static inline int gadget_is_dualspeed(struct usb_gadget *g) 496 { 497 return g->max_speed >= USB_SPEED_HIGH; 498 } 499 500 /** 501 * gadget_is_superspeed() - return true if the hardware handles superspeed 502 * @g: controller that might support superspeed 503 */ 504 static inline int gadget_is_superspeed(struct usb_gadget *g) 505 { 506 return g->max_speed >= USB_SPEED_SUPER; 507 } 508 509 /** 510 * gadget_is_superspeed_plus() - return true if the hardware handles 511 * superspeed plus 512 * @g: controller that might support superspeed plus 513 */ 514 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 515 { 516 return g->max_speed >= USB_SPEED_SUPER_PLUS; 517 } 518 519 /** 520 * gadget_is_otg - return true iff the hardware is OTG-ready 521 * @g: controller that might have a Mini-AB connector 522 * 523 * This is a runtime test, since kernels with a USB-OTG stack sometimes 524 * run on boards which only have a Mini-B (or Mini-A) connector. 525 */ 526 static inline int gadget_is_otg(struct usb_gadget *g) 527 { 528 #ifdef CONFIG_USB_OTG 529 return g->is_otg; 530 #else 531 return 0; 532 #endif 533 } 534 535 /*-------------------------------------------------------------------------*/ 536 537 #if IS_ENABLED(CONFIG_USB_GADGET) 538 int usb_gadget_frame_number(struct usb_gadget *gadget); 539 int usb_gadget_wakeup(struct usb_gadget *gadget); 540 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 541 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 542 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 543 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 544 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 545 int usb_gadget_connect(struct usb_gadget *gadget); 546 int usb_gadget_disconnect(struct usb_gadget *gadget); 547 int usb_gadget_deactivate(struct usb_gadget *gadget); 548 int usb_gadget_activate(struct usb_gadget *gadget); 549 #else 550 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 551 { return 0; } 552 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 553 { return 0; } 554 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 555 { return 0; } 556 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 557 { return 0; } 558 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 559 { return 0; } 560 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 561 { return 0; } 562 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 563 { return 0; } 564 static inline int usb_gadget_connect(struct usb_gadget *gadget) 565 { return 0; } 566 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 567 { return 0; } 568 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 569 { return 0; } 570 static inline int usb_gadget_activate(struct usb_gadget *gadget) 571 { return 0; } 572 #endif /* CONFIG_USB_GADGET */ 573 574 /*-------------------------------------------------------------------------*/ 575 576 /** 577 * struct usb_gadget_driver - driver for usb 'slave' devices 578 * @function: String describing the gadget's function 579 * @max_speed: Highest speed the driver handles. 580 * @setup: Invoked for ep0 control requests that aren't handled by 581 * the hardware level driver. Most calls must be handled by 582 * the gadget driver, including descriptor and configuration 583 * management. The 16 bit members of the setup data are in 584 * USB byte order. Called in_interrupt; this may not sleep. Driver 585 * queues a response to ep0, or returns negative to stall. 586 * @disconnect: Invoked after all transfers have been stopped, 587 * when the host is disconnected. May be called in_interrupt; this 588 * may not sleep. Some devices can't detect disconnect, so this might 589 * not be called except as part of controller shutdown. 590 * @bind: the driver's bind callback 591 * @unbind: Invoked when the driver is unbound from a gadget, 592 * usually from rmmod (after a disconnect is reported). 593 * Called in a context that permits sleeping. 594 * @suspend: Invoked on USB suspend. May be called in_interrupt. 595 * @resume: Invoked on USB resume. May be called in_interrupt. 596 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 597 * and should be called in_interrupt. 598 * @driver: Driver model state for this driver. 599 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 600 * this driver will be bound to any available UDC. 601 * @pending: UDC core private data used for deferred probe of this driver. 602 * @match_existing_only: If udc is not found, return an error and don't add this 603 * gadget driver to list of pending driver 604 * 605 * Devices are disabled till a gadget driver successfully bind()s, which 606 * means the driver will handle setup() requests needed to enumerate (and 607 * meet "chapter 9" requirements) then do some useful work. 608 * 609 * If gadget->is_otg is true, the gadget driver must provide an OTG 610 * descriptor during enumeration, or else fail the bind() call. In such 611 * cases, no USB traffic may flow until both bind() returns without 612 * having called usb_gadget_disconnect(), and the USB host stack has 613 * initialized. 614 * 615 * Drivers use hardware-specific knowledge to configure the usb hardware. 616 * endpoint addressing is only one of several hardware characteristics that 617 * are in descriptors the ep0 implementation returns from setup() calls. 618 * 619 * Except for ep0 implementation, most driver code shouldn't need change to 620 * run on top of different usb controllers. It'll use endpoints set up by 621 * that ep0 implementation. 622 * 623 * The usb controller driver handles a few standard usb requests. Those 624 * include set_address, and feature flags for devices, interfaces, and 625 * endpoints (the get_status, set_feature, and clear_feature requests). 626 * 627 * Accordingly, the driver's setup() callback must always implement all 628 * get_descriptor requests, returning at least a device descriptor and 629 * a configuration descriptor. Drivers must make sure the endpoint 630 * descriptors match any hardware constraints. Some hardware also constrains 631 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 632 * 633 * The driver's setup() callback must also implement set_configuration, 634 * and should also implement set_interface, get_configuration, and 635 * get_interface. Setting a configuration (or interface) is where 636 * endpoints should be activated or (config 0) shut down. 637 * 638 * (Note that only the default control endpoint is supported. Neither 639 * hosts nor devices generally support control traffic except to ep0.) 640 * 641 * Most devices will ignore USB suspend/resume operations, and so will 642 * not provide those callbacks. However, some may need to change modes 643 * when the host is not longer directing those activities. For example, 644 * local controls (buttons, dials, etc) may need to be re-enabled since 645 * the (remote) host can't do that any longer; or an error state might 646 * be cleared, to make the device behave identically whether or not 647 * power is maintained. 648 */ 649 struct usb_gadget_driver { 650 char *function; 651 enum usb_device_speed max_speed; 652 int (*bind)(struct usb_gadget *gadget, 653 struct usb_gadget_driver *driver); 654 void (*unbind)(struct usb_gadget *); 655 int (*setup)(struct usb_gadget *, 656 const struct usb_ctrlrequest *); 657 void (*disconnect)(struct usb_gadget *); 658 void (*suspend)(struct usb_gadget *); 659 void (*resume)(struct usb_gadget *); 660 void (*reset)(struct usb_gadget *); 661 662 /* FIXME support safe rmmod */ 663 struct device_driver driver; 664 665 char *udc_name; 666 struct list_head pending; 667 unsigned match_existing_only:1; 668 }; 669 670 671 672 /*-------------------------------------------------------------------------*/ 673 674 /* driver modules register and unregister, as usual. 675 * these calls must be made in a context that can sleep. 676 * 677 * these will usually be implemented directly by the hardware-dependent 678 * usb bus interface driver, which will only support a single driver. 679 */ 680 681 /** 682 * usb_gadget_probe_driver - probe a gadget driver 683 * @driver: the driver being registered 684 * Context: can sleep 685 * 686 * Call this in your gadget driver's module initialization function, 687 * to tell the underlying usb controller driver about your driver. 688 * The @bind() function will be called to bind it to a gadget before this 689 * registration call returns. It's expected that the @bind() function will 690 * be in init sections. 691 */ 692 int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 693 694 /** 695 * usb_gadget_unregister_driver - unregister a gadget driver 696 * @driver:the driver being unregistered 697 * Context: can sleep 698 * 699 * Call this in your gadget driver's module cleanup function, 700 * to tell the underlying usb controller that your driver is 701 * going away. If the controller is connected to a USB host, 702 * it will first disconnect(). The driver is also requested 703 * to unbind() and clean up any device state, before this procedure 704 * finally returns. It's expected that the unbind() functions 705 * will in in exit sections, so may not be linked in some kernels. 706 */ 707 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 708 709 extern int usb_add_gadget_udc_release(struct device *parent, 710 struct usb_gadget *gadget, void (*release)(struct device *dev)); 711 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 712 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 713 extern char *usb_get_gadget_udc_name(void); 714 715 /*-------------------------------------------------------------------------*/ 716 717 /* utility to simplify dealing with string descriptors */ 718 719 /** 720 * struct usb_string - wraps a C string and its USB id 721 * @id:the (nonzero) ID for this string 722 * @s:the string, in UTF-8 encoding 723 * 724 * If you're using usb_gadget_get_string(), use this to wrap a string 725 * together with its ID. 726 */ 727 struct usb_string { 728 u8 id; 729 const char *s; 730 }; 731 732 /** 733 * struct usb_gadget_strings - a set of USB strings in a given language 734 * @language:identifies the strings' language (0x0409 for en-us) 735 * @strings:array of strings with their ids 736 * 737 * If you're using usb_gadget_get_string(), use this to wrap all the 738 * strings for a given language. 739 */ 740 struct usb_gadget_strings { 741 u16 language; /* 0x0409 for en-us */ 742 struct usb_string *strings; 743 }; 744 745 struct usb_gadget_string_container { 746 struct list_head list; 747 u8 *stash[0]; 748 }; 749 750 /* put descriptor for string with that id into buf (buflen >= 256) */ 751 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 752 753 /*-------------------------------------------------------------------------*/ 754 755 /* utility to simplify managing config descriptors */ 756 757 /* write vector of descriptors into buffer */ 758 int usb_descriptor_fillbuf(void *, unsigned, 759 const struct usb_descriptor_header **); 760 761 /* build config descriptor from single descriptor vector */ 762 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 763 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 764 765 /* copy a NULL-terminated vector of descriptors */ 766 struct usb_descriptor_header **usb_copy_descriptors( 767 struct usb_descriptor_header **); 768 769 /** 770 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 771 * @v: vector of descriptors 772 */ 773 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 774 { 775 kfree(v); 776 } 777 778 struct usb_function; 779 int usb_assign_descriptors(struct usb_function *f, 780 struct usb_descriptor_header **fs, 781 struct usb_descriptor_header **hs, 782 struct usb_descriptor_header **ss, 783 struct usb_descriptor_header **ssp); 784 void usb_free_all_descriptors(struct usb_function *f); 785 786 struct usb_descriptor_header *usb_otg_descriptor_alloc( 787 struct usb_gadget *gadget); 788 int usb_otg_descriptor_init(struct usb_gadget *gadget, 789 struct usb_descriptor_header *otg_desc); 790 /*-------------------------------------------------------------------------*/ 791 792 /* utility to simplify map/unmap of usb_requests to/from DMA */ 793 794 extern int usb_gadget_map_request_by_dev(struct device *dev, 795 struct usb_request *req, int is_in); 796 extern int usb_gadget_map_request(struct usb_gadget *gadget, 797 struct usb_request *req, int is_in); 798 799 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 800 struct usb_request *req, int is_in); 801 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 802 struct usb_request *req, int is_in); 803 804 /*-------------------------------------------------------------------------*/ 805 806 /* utility to set gadget state properly */ 807 808 extern void usb_gadget_set_state(struct usb_gadget *gadget, 809 enum usb_device_state state); 810 811 /*-------------------------------------------------------------------------*/ 812 813 /* utility to tell udc core that the bus reset occurs */ 814 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 815 struct usb_gadget_driver *driver); 816 817 /*-------------------------------------------------------------------------*/ 818 819 /* utility to give requests back to the gadget layer */ 820 821 extern void usb_gadget_giveback_request(struct usb_ep *ep, 822 struct usb_request *req); 823 824 /*-------------------------------------------------------------------------*/ 825 826 /* utility to find endpoint by name */ 827 828 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 829 const char *name); 830 831 /*-------------------------------------------------------------------------*/ 832 833 /* utility to check if endpoint caps match descriptor needs */ 834 835 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 836 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 837 struct usb_ss_ep_comp_descriptor *ep_comp); 838 839 /*-------------------------------------------------------------------------*/ 840 841 /* utility to update vbus status for udc core, it may be scheduled */ 842 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 843 844 /*-------------------------------------------------------------------------*/ 845 846 /* utility wrapping a simple endpoint selection policy */ 847 848 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 849 struct usb_endpoint_descriptor *); 850 851 852 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 853 struct usb_endpoint_descriptor *, 854 struct usb_ss_ep_comp_descriptor *); 855 856 extern void usb_ep_autoconfig_release(struct usb_ep *); 857 858 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 859 860 #endif /* __LINUX_USB_GADGET_H */ 861