1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * <linux/usb/gadget.h> 4 * 5 * We call the USB code inside a Linux-based peripheral device a "gadget" 6 * driver, except for the hardware-specific bus glue. One USB host can 7 * master many USB gadgets, but the gadgets are only slaved to one host. 8 * 9 * 10 * (C) Copyright 2002-2004 by David Brownell 11 * All Rights Reserved. 12 * 13 * This software is licensed under the GNU GPL version 2. 14 */ 15 16 #ifndef __LINUX_USB_GADGET_H 17 #define __LINUX_USB_GADGET_H 18 19 #include <linux/device.h> 20 #include <linux/errno.h> 21 #include <linux/init.h> 22 #include <linux/list.h> 23 #include <linux/slab.h> 24 #include <linux/scatterlist.h> 25 #include <linux/types.h> 26 #include <linux/workqueue.h> 27 #include <linux/usb/ch9.h> 28 29 #define UDC_TRACE_STR_MAX 512 30 31 struct usb_ep; 32 33 /** 34 * struct usb_request - describes one i/o request 35 * @buf: Buffer used for data. Always provide this; some controllers 36 * only use PIO, or don't use DMA for some endpoints. 37 * @dma: DMA address corresponding to 'buf'. If you don't set this 38 * field, and the usb controller needs one, it is responsible 39 * for mapping and unmapping the buffer. 40 * @sg: a scatterlist for SG-capable controllers. 41 * @num_sgs: number of SG entries 42 * @num_mapped_sgs: number of SG entries mapped to DMA (internal) 43 * @length: Length of that data 44 * @stream_id: The stream id, when USB3.0 bulk streams are being used 45 * @no_interrupt: If true, hints that no completion irq is needed. 46 * Helpful sometimes with deep request queues that are handled 47 * directly by DMA controllers. 48 * @zero: If true, when writing data, makes the last packet be "short" 49 * by adding a zero length packet as needed; 50 * @short_not_ok: When reading data, makes short packets be 51 * treated as errors (queue stops advancing till cleanup). 52 * @dma_mapped: Indicates if request has been mapped to DMA (internal) 53 * @complete: Function called when request completes, so this request and 54 * its buffer may be re-used. The function will always be called with 55 * interrupts disabled, and it must not sleep. 56 * Reads terminate with a short packet, or when the buffer fills, 57 * whichever comes first. When writes terminate, some data bytes 58 * will usually still be in flight (often in a hardware fifo). 59 * Errors (for reads or writes) stop the queue from advancing 60 * until the completion function returns, so that any transfers 61 * invalidated by the error may first be dequeued. 62 * @context: For use by the completion callback 63 * @list: For use by the gadget driver. 64 * @status: Reports completion code, zero or a negative errno. 65 * Normally, faults block the transfer queue from advancing until 66 * the completion callback returns. 67 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 68 * or when the driver disabled the endpoint. 69 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 70 * transfers) this may be less than the requested length. If the 71 * short_not_ok flag is set, short reads are treated as errors 72 * even when status otherwise indicates successful completion. 73 * Note that for writes (IN transfers) some data bytes may still 74 * reside in a device-side FIFO when the request is reported as 75 * complete. 76 * 77 * These are allocated/freed through the endpoint they're used with. The 78 * hardware's driver can add extra per-request data to the memory it returns, 79 * which often avoids separate memory allocations (potential failures), 80 * later when the request is queued. 81 * 82 * Request flags affect request handling, such as whether a zero length 83 * packet is written (the "zero" flag), whether a short read should be 84 * treated as an error (blocking request queue advance, the "short_not_ok" 85 * flag), or hinting that an interrupt is not required (the "no_interrupt" 86 * flag, for use with deep request queues). 87 * 88 * Bulk endpoints can use any size buffers, and can also be used for interrupt 89 * transfers. interrupt-only endpoints can be much less functional. 90 * 91 * NOTE: this is analogous to 'struct urb' on the host side, except that 92 * it's thinner and promotes more pre-allocation. 93 */ 94 95 struct usb_request { 96 void *buf; 97 unsigned length; 98 dma_addr_t dma; 99 100 struct scatterlist *sg; 101 unsigned num_sgs; 102 unsigned num_mapped_sgs; 103 104 unsigned stream_id:16; 105 unsigned no_interrupt:1; 106 unsigned zero:1; 107 unsigned short_not_ok:1; 108 unsigned dma_mapped:1; 109 110 void (*complete)(struct usb_ep *ep, 111 struct usb_request *req); 112 void *context; 113 struct list_head list; 114 115 int status; 116 unsigned actual; 117 }; 118 119 /*-------------------------------------------------------------------------*/ 120 121 /* endpoint-specific parts of the api to the usb controller hardware. 122 * unlike the urb model, (de)multiplexing layers are not required. 123 * (so this api could slash overhead if used on the host side...) 124 * 125 * note that device side usb controllers commonly differ in how many 126 * endpoints they support, as well as their capabilities. 127 */ 128 struct usb_ep_ops { 129 int (*enable) (struct usb_ep *ep, 130 const struct usb_endpoint_descriptor *desc); 131 int (*disable) (struct usb_ep *ep); 132 133 struct usb_request *(*alloc_request) (struct usb_ep *ep, 134 gfp_t gfp_flags); 135 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 136 137 int (*queue) (struct usb_ep *ep, struct usb_request *req, 138 gfp_t gfp_flags); 139 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 140 141 int (*set_halt) (struct usb_ep *ep, int value); 142 int (*set_wedge) (struct usb_ep *ep); 143 144 int (*fifo_status) (struct usb_ep *ep); 145 void (*fifo_flush) (struct usb_ep *ep); 146 }; 147 148 /** 149 * struct usb_ep_caps - endpoint capabilities description 150 * @type_control:Endpoint supports control type (reserved for ep0). 151 * @type_iso:Endpoint supports isochronous transfers. 152 * @type_bulk:Endpoint supports bulk transfers. 153 * @type_int:Endpoint supports interrupt transfers. 154 * @dir_in:Endpoint supports IN direction. 155 * @dir_out:Endpoint supports OUT direction. 156 */ 157 struct usb_ep_caps { 158 unsigned type_control:1; 159 unsigned type_iso:1; 160 unsigned type_bulk:1; 161 unsigned type_int:1; 162 unsigned dir_in:1; 163 unsigned dir_out:1; 164 }; 165 166 #define USB_EP_CAPS_TYPE_CONTROL 0x01 167 #define USB_EP_CAPS_TYPE_ISO 0x02 168 #define USB_EP_CAPS_TYPE_BULK 0x04 169 #define USB_EP_CAPS_TYPE_INT 0x08 170 #define USB_EP_CAPS_TYPE_ALL \ 171 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 172 #define USB_EP_CAPS_DIR_IN 0x01 173 #define USB_EP_CAPS_DIR_OUT 0x02 174 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 175 176 #define USB_EP_CAPS(_type, _dir) \ 177 { \ 178 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 179 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 180 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 181 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 182 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 183 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 184 } 185 186 /** 187 * struct usb_ep - device side representation of USB endpoint 188 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 189 * @ops: Function pointers used to access hardware-specific operations. 190 * @ep_list:the gadget's ep_list holds all of its endpoints 191 * @caps:The structure describing types and directions supported by endoint. 192 * @enabled: The current endpoint enabled/disabled state. 193 * @claimed: True if this endpoint is claimed by a function. 194 * @maxpacket:The maximum packet size used on this endpoint. The initial 195 * value can sometimes be reduced (hardware allowing), according to 196 * the endpoint descriptor used to configure the endpoint. 197 * @maxpacket_limit:The maximum packet size value which can be handled by this 198 * endpoint. It's set once by UDC driver when endpoint is initialized, and 199 * should not be changed. Should not be confused with maxpacket. 200 * @max_streams: The maximum number of streams supported 201 * by this EP (0 - 16, actual number is 2^n) 202 * @mult: multiplier, 'mult' value for SS Isoc EPs 203 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 204 * @driver_data:for use by the gadget driver. 205 * @address: used to identify the endpoint when finding descriptor that 206 * matches connection speed 207 * @desc: endpoint descriptor. This pointer is set before the endpoint is 208 * enabled and remains valid until the endpoint is disabled. 209 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 210 * descriptor that is used to configure the endpoint 211 * 212 * the bus controller driver lists all the general purpose endpoints in 213 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 214 * and is accessed only in response to a driver setup() callback. 215 */ 216 217 struct usb_ep { 218 void *driver_data; 219 220 const char *name; 221 const struct usb_ep_ops *ops; 222 struct list_head ep_list; 223 struct usb_ep_caps caps; 224 bool claimed; 225 bool enabled; 226 unsigned maxpacket:16; 227 unsigned maxpacket_limit:16; 228 unsigned max_streams:16; 229 unsigned mult:2; 230 unsigned maxburst:5; 231 u8 address; 232 const struct usb_endpoint_descriptor *desc; 233 const struct usb_ss_ep_comp_descriptor *comp_desc; 234 }; 235 236 /*-------------------------------------------------------------------------*/ 237 238 #if IS_ENABLED(CONFIG_USB_GADGET) 239 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); 240 int usb_ep_enable(struct usb_ep *ep); 241 int usb_ep_disable(struct usb_ep *ep); 242 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); 243 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); 244 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); 245 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); 246 int usb_ep_set_halt(struct usb_ep *ep); 247 int usb_ep_clear_halt(struct usb_ep *ep); 248 int usb_ep_set_wedge(struct usb_ep *ep); 249 int usb_ep_fifo_status(struct usb_ep *ep); 250 void usb_ep_fifo_flush(struct usb_ep *ep); 251 #else 252 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 253 unsigned maxpacket_limit) 254 { } 255 static inline int usb_ep_enable(struct usb_ep *ep) 256 { return 0; } 257 static inline int usb_ep_disable(struct usb_ep *ep) 258 { return 0; } 259 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 260 gfp_t gfp_flags) 261 { return NULL; } 262 static inline void usb_ep_free_request(struct usb_ep *ep, 263 struct usb_request *req) 264 { } 265 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, 266 gfp_t gfp_flags) 267 { return 0; } 268 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 269 { return 0; } 270 static inline int usb_ep_set_halt(struct usb_ep *ep) 271 { return 0; } 272 static inline int usb_ep_clear_halt(struct usb_ep *ep) 273 { return 0; } 274 static inline int usb_ep_set_wedge(struct usb_ep *ep) 275 { return 0; } 276 static inline int usb_ep_fifo_status(struct usb_ep *ep) 277 { return 0; } 278 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 279 { } 280 #endif /* USB_GADGET */ 281 282 /*-------------------------------------------------------------------------*/ 283 284 struct usb_dcd_config_params { 285 __u8 bU1devExitLat; /* U1 Device exit Latency */ 286 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 287 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 288 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 289 }; 290 291 292 struct usb_gadget; 293 struct usb_gadget_driver; 294 struct usb_udc; 295 296 /* the rest of the api to the controller hardware: device operations, 297 * which don't involve endpoints (or i/o). 298 */ 299 struct usb_gadget_ops { 300 int (*get_frame)(struct usb_gadget *); 301 int (*wakeup)(struct usb_gadget *); 302 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 303 int (*vbus_session) (struct usb_gadget *, int is_active); 304 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 305 int (*pullup) (struct usb_gadget *, int is_on); 306 int (*ioctl)(struct usb_gadget *, 307 unsigned code, unsigned long param); 308 void (*get_config_params)(struct usb_dcd_config_params *); 309 int (*udc_start)(struct usb_gadget *, 310 struct usb_gadget_driver *); 311 int (*udc_stop)(struct usb_gadget *); 312 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed); 313 struct usb_ep *(*match_ep)(struct usb_gadget *, 314 struct usb_endpoint_descriptor *, 315 struct usb_ss_ep_comp_descriptor *); 316 }; 317 318 /** 319 * struct usb_gadget - represents a usb slave device 320 * @work: (internal use) Workqueue to be used for sysfs_notify() 321 * @udc: struct usb_udc pointer for this gadget 322 * @ops: Function pointers used to access hardware-specific operations. 323 * @ep0: Endpoint zero, used when reading or writing responses to 324 * driver setup() requests 325 * @ep_list: List of other endpoints supported by the device. 326 * @speed: Speed of current connection to USB host. 327 * @max_speed: Maximal speed the UDC can handle. UDC must support this 328 * and all slower speeds. 329 * @state: the state we are now (attached, suspended, configured, etc) 330 * @name: Identifies the controller hardware type. Used in diagnostics 331 * and sometimes configuration. 332 * @dev: Driver model state for this abstract device. 333 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP 334 * @out_epnum: last used out ep number 335 * @in_epnum: last used in ep number 336 * @mA: last set mA value 337 * @otg_caps: OTG capabilities of this gadget. 338 * @sg_supported: true if we can handle scatter-gather 339 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 340 * gadget driver must provide a USB OTG descriptor. 341 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 342 * is in the Mini-AB jack, and HNP has been used to switch roles 343 * so that the "A" device currently acts as A-Peripheral, not A-Host. 344 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 345 * supports HNP at this port. 346 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 347 * only supports HNP on a different root port. 348 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 349 * enabled HNP support. 350 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 351 * in peripheral mode can support HNP polling. 352 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 353 * or B-Peripheral wants to take host role. 354 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 355 * MaxPacketSize. 356 * @quirk_altset_not_supp: UDC controller doesn't support alt settings. 357 * @quirk_stall_not_supp: UDC controller doesn't support stalling. 358 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP. 359 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 360 * u_ether.c to improve performance. 361 * @is_selfpowered: if the gadget is self-powered. 362 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 363 * be connected. 364 * @connected: True if gadget is connected. 365 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag 366 * indicates that it supports LPM as per the LPM ECN & errata. 367 * 368 * Gadgets have a mostly-portable "gadget driver" implementing device 369 * functions, handling all usb configurations and interfaces. Gadget 370 * drivers talk to hardware-specific code indirectly, through ops vectors. 371 * That insulates the gadget driver from hardware details, and packages 372 * the hardware endpoints through generic i/o queues. The "usb_gadget" 373 * and "usb_ep" interfaces provide that insulation from the hardware. 374 * 375 * Except for the driver data, all fields in this structure are 376 * read-only to the gadget driver. That driver data is part of the 377 * "driver model" infrastructure in 2.6 (and later) kernels, and for 378 * earlier systems is grouped in a similar structure that's not known 379 * to the rest of the kernel. 380 * 381 * Values of the three OTG device feature flags are updated before the 382 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 383 * driver suspend() calls. They are valid only when is_otg, and when the 384 * device is acting as a B-Peripheral (so is_a_peripheral is false). 385 */ 386 struct usb_gadget { 387 struct work_struct work; 388 struct usb_udc *udc; 389 /* readonly to gadget driver */ 390 const struct usb_gadget_ops *ops; 391 struct usb_ep *ep0; 392 struct list_head ep_list; /* of usb_ep */ 393 enum usb_device_speed speed; 394 enum usb_device_speed max_speed; 395 enum usb_device_state state; 396 const char *name; 397 struct device dev; 398 unsigned isoch_delay; 399 unsigned out_epnum; 400 unsigned in_epnum; 401 unsigned mA; 402 struct usb_otg_caps *otg_caps; 403 404 unsigned sg_supported:1; 405 unsigned is_otg:1; 406 unsigned is_a_peripheral:1; 407 unsigned b_hnp_enable:1; 408 unsigned a_hnp_support:1; 409 unsigned a_alt_hnp_support:1; 410 unsigned hnp_polling_support:1; 411 unsigned host_request_flag:1; 412 unsigned quirk_ep_out_aligned_size:1; 413 unsigned quirk_altset_not_supp:1; 414 unsigned quirk_stall_not_supp:1; 415 unsigned quirk_zlp_not_supp:1; 416 unsigned quirk_avoids_skb_reserve:1; 417 unsigned is_selfpowered:1; 418 unsigned deactivated:1; 419 unsigned connected:1; 420 unsigned lpm_capable:1; 421 }; 422 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 423 424 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 425 { dev_set_drvdata(&gadget->dev, data); } 426 static inline void *get_gadget_data(struct usb_gadget *gadget) 427 { return dev_get_drvdata(&gadget->dev); } 428 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 429 { 430 return container_of(dev, struct usb_gadget, dev); 431 } 432 433 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 434 #define gadget_for_each_ep(tmp, gadget) \ 435 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 436 437 /** 438 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 439 * @ep: the endpoint whose maxpacketsize is used to align @len 440 * @len: buffer size's length to align to @ep's maxpacketsize 441 * 442 * This helper is used to align buffer's size to an ep's maxpacketsize. 443 */ 444 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 445 { 446 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff; 447 448 return round_up(len, max_packet_size); 449 } 450 451 /** 452 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 453 * requires quirk_ep_out_aligned_size, otherwise returns len. 454 * @g: controller to check for quirk 455 * @ep: the endpoint whose maxpacketsize is used to align @len 456 * @len: buffer size's length to align to @ep's maxpacketsize 457 * 458 * This helper is used in case it's required for any reason to check and maybe 459 * align buffer's size to an ep's maxpacketsize. 460 */ 461 static inline size_t 462 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 463 { 464 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 465 } 466 467 /** 468 * gadget_is_altset_supported - return true iff the hardware supports 469 * altsettings 470 * @g: controller to check for quirk 471 */ 472 static inline int gadget_is_altset_supported(struct usb_gadget *g) 473 { 474 return !g->quirk_altset_not_supp; 475 } 476 477 /** 478 * gadget_is_stall_supported - return true iff the hardware supports stalling 479 * @g: controller to check for quirk 480 */ 481 static inline int gadget_is_stall_supported(struct usb_gadget *g) 482 { 483 return !g->quirk_stall_not_supp; 484 } 485 486 /** 487 * gadget_is_zlp_supported - return true iff the hardware supports zlp 488 * @g: controller to check for quirk 489 */ 490 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 491 { 492 return !g->quirk_zlp_not_supp; 493 } 494 495 /** 496 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 497 * skb_reserve to improve performance. 498 * @g: controller to check for quirk 499 */ 500 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 501 { 502 return g->quirk_avoids_skb_reserve; 503 } 504 505 /** 506 * gadget_is_dualspeed - return true iff the hardware handles high speed 507 * @g: controller that might support both high and full speeds 508 */ 509 static inline int gadget_is_dualspeed(struct usb_gadget *g) 510 { 511 return g->max_speed >= USB_SPEED_HIGH; 512 } 513 514 /** 515 * gadget_is_superspeed() - return true if the hardware handles superspeed 516 * @g: controller that might support superspeed 517 */ 518 static inline int gadget_is_superspeed(struct usb_gadget *g) 519 { 520 return g->max_speed >= USB_SPEED_SUPER; 521 } 522 523 /** 524 * gadget_is_superspeed_plus() - return true if the hardware handles 525 * superspeed plus 526 * @g: controller that might support superspeed plus 527 */ 528 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 529 { 530 return g->max_speed >= USB_SPEED_SUPER_PLUS; 531 } 532 533 /** 534 * gadget_is_otg - return true iff the hardware is OTG-ready 535 * @g: controller that might have a Mini-AB connector 536 * 537 * This is a runtime test, since kernels with a USB-OTG stack sometimes 538 * run on boards which only have a Mini-B (or Mini-A) connector. 539 */ 540 static inline int gadget_is_otg(struct usb_gadget *g) 541 { 542 #ifdef CONFIG_USB_OTG 543 return g->is_otg; 544 #else 545 return 0; 546 #endif 547 } 548 549 /*-------------------------------------------------------------------------*/ 550 551 #if IS_ENABLED(CONFIG_USB_GADGET) 552 int usb_gadget_frame_number(struct usb_gadget *gadget); 553 int usb_gadget_wakeup(struct usb_gadget *gadget); 554 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 555 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 556 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 557 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 558 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 559 int usb_gadget_connect(struct usb_gadget *gadget); 560 int usb_gadget_disconnect(struct usb_gadget *gadget); 561 int usb_gadget_deactivate(struct usb_gadget *gadget); 562 int usb_gadget_activate(struct usb_gadget *gadget); 563 #else 564 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 565 { return 0; } 566 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 567 { return 0; } 568 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 569 { return 0; } 570 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 571 { return 0; } 572 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 573 { return 0; } 574 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 575 { return 0; } 576 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 577 { return 0; } 578 static inline int usb_gadget_connect(struct usb_gadget *gadget) 579 { return 0; } 580 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 581 { return 0; } 582 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 583 { return 0; } 584 static inline int usb_gadget_activate(struct usb_gadget *gadget) 585 { return 0; } 586 #endif /* CONFIG_USB_GADGET */ 587 588 /*-------------------------------------------------------------------------*/ 589 590 /** 591 * struct usb_gadget_driver - driver for usb 'slave' devices 592 * @function: String describing the gadget's function 593 * @max_speed: Highest speed the driver handles. 594 * @setup: Invoked for ep0 control requests that aren't handled by 595 * the hardware level driver. Most calls must be handled by 596 * the gadget driver, including descriptor and configuration 597 * management. The 16 bit members of the setup data are in 598 * USB byte order. Called in_interrupt; this may not sleep. Driver 599 * queues a response to ep0, or returns negative to stall. 600 * @disconnect: Invoked after all transfers have been stopped, 601 * when the host is disconnected. May be called in_interrupt; this 602 * may not sleep. Some devices can't detect disconnect, so this might 603 * not be called except as part of controller shutdown. 604 * @bind: the driver's bind callback 605 * @unbind: Invoked when the driver is unbound from a gadget, 606 * usually from rmmod (after a disconnect is reported). 607 * Called in a context that permits sleeping. 608 * @suspend: Invoked on USB suspend. May be called in_interrupt. 609 * @resume: Invoked on USB resume. May be called in_interrupt. 610 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 611 * and should be called in_interrupt. 612 * @driver: Driver model state for this driver. 613 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 614 * this driver will be bound to any available UDC. 615 * @pending: UDC core private data used for deferred probe of this driver. 616 * @match_existing_only: If udc is not found, return an error and don't add this 617 * gadget driver to list of pending driver 618 * 619 * Devices are disabled till a gadget driver successfully bind()s, which 620 * means the driver will handle setup() requests needed to enumerate (and 621 * meet "chapter 9" requirements) then do some useful work. 622 * 623 * If gadget->is_otg is true, the gadget driver must provide an OTG 624 * descriptor during enumeration, or else fail the bind() call. In such 625 * cases, no USB traffic may flow until both bind() returns without 626 * having called usb_gadget_disconnect(), and the USB host stack has 627 * initialized. 628 * 629 * Drivers use hardware-specific knowledge to configure the usb hardware. 630 * endpoint addressing is only one of several hardware characteristics that 631 * are in descriptors the ep0 implementation returns from setup() calls. 632 * 633 * Except for ep0 implementation, most driver code shouldn't need change to 634 * run on top of different usb controllers. It'll use endpoints set up by 635 * that ep0 implementation. 636 * 637 * The usb controller driver handles a few standard usb requests. Those 638 * include set_address, and feature flags for devices, interfaces, and 639 * endpoints (the get_status, set_feature, and clear_feature requests). 640 * 641 * Accordingly, the driver's setup() callback must always implement all 642 * get_descriptor requests, returning at least a device descriptor and 643 * a configuration descriptor. Drivers must make sure the endpoint 644 * descriptors match any hardware constraints. Some hardware also constrains 645 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 646 * 647 * The driver's setup() callback must also implement set_configuration, 648 * and should also implement set_interface, get_configuration, and 649 * get_interface. Setting a configuration (or interface) is where 650 * endpoints should be activated or (config 0) shut down. 651 * 652 * (Note that only the default control endpoint is supported. Neither 653 * hosts nor devices generally support control traffic except to ep0.) 654 * 655 * Most devices will ignore USB suspend/resume operations, and so will 656 * not provide those callbacks. However, some may need to change modes 657 * when the host is not longer directing those activities. For example, 658 * local controls (buttons, dials, etc) may need to be re-enabled since 659 * the (remote) host can't do that any longer; or an error state might 660 * be cleared, to make the device behave identically whether or not 661 * power is maintained. 662 */ 663 struct usb_gadget_driver { 664 char *function; 665 enum usb_device_speed max_speed; 666 int (*bind)(struct usb_gadget *gadget, 667 struct usb_gadget_driver *driver); 668 void (*unbind)(struct usb_gadget *); 669 int (*setup)(struct usb_gadget *, 670 const struct usb_ctrlrequest *); 671 void (*disconnect)(struct usb_gadget *); 672 void (*suspend)(struct usb_gadget *); 673 void (*resume)(struct usb_gadget *); 674 void (*reset)(struct usb_gadget *); 675 676 /* FIXME support safe rmmod */ 677 struct device_driver driver; 678 679 char *udc_name; 680 struct list_head pending; 681 unsigned match_existing_only:1; 682 }; 683 684 685 686 /*-------------------------------------------------------------------------*/ 687 688 /* driver modules register and unregister, as usual. 689 * these calls must be made in a context that can sleep. 690 * 691 * these will usually be implemented directly by the hardware-dependent 692 * usb bus interface driver, which will only support a single driver. 693 */ 694 695 /** 696 * usb_gadget_probe_driver - probe a gadget driver 697 * @driver: the driver being registered 698 * Context: can sleep 699 * 700 * Call this in your gadget driver's module initialization function, 701 * to tell the underlying usb controller driver about your driver. 702 * The @bind() function will be called to bind it to a gadget before this 703 * registration call returns. It's expected that the @bind() function will 704 * be in init sections. 705 */ 706 int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 707 708 /** 709 * usb_gadget_unregister_driver - unregister a gadget driver 710 * @driver:the driver being unregistered 711 * Context: can sleep 712 * 713 * Call this in your gadget driver's module cleanup function, 714 * to tell the underlying usb controller that your driver is 715 * going away. If the controller is connected to a USB host, 716 * it will first disconnect(). The driver is also requested 717 * to unbind() and clean up any device state, before this procedure 718 * finally returns. It's expected that the unbind() functions 719 * will in in exit sections, so may not be linked in some kernels. 720 */ 721 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 722 723 extern int usb_add_gadget_udc_release(struct device *parent, 724 struct usb_gadget *gadget, void (*release)(struct device *dev)); 725 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 726 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 727 extern char *usb_get_gadget_udc_name(void); 728 729 /*-------------------------------------------------------------------------*/ 730 731 /* utility to simplify dealing with string descriptors */ 732 733 /** 734 * struct usb_string - wraps a C string and its USB id 735 * @id:the (nonzero) ID for this string 736 * @s:the string, in UTF-8 encoding 737 * 738 * If you're using usb_gadget_get_string(), use this to wrap a string 739 * together with its ID. 740 */ 741 struct usb_string { 742 u8 id; 743 const char *s; 744 }; 745 746 /** 747 * struct usb_gadget_strings - a set of USB strings in a given language 748 * @language:identifies the strings' language (0x0409 for en-us) 749 * @strings:array of strings with their ids 750 * 751 * If you're using usb_gadget_get_string(), use this to wrap all the 752 * strings for a given language. 753 */ 754 struct usb_gadget_strings { 755 u16 language; /* 0x0409 for en-us */ 756 struct usb_string *strings; 757 }; 758 759 struct usb_gadget_string_container { 760 struct list_head list; 761 u8 *stash[0]; 762 }; 763 764 /* put descriptor for string with that id into buf (buflen >= 256) */ 765 int usb_gadget_get_string(struct usb_gadget_strings *table, int id, u8 *buf); 766 767 /*-------------------------------------------------------------------------*/ 768 769 /* utility to simplify managing config descriptors */ 770 771 /* write vector of descriptors into buffer */ 772 int usb_descriptor_fillbuf(void *, unsigned, 773 const struct usb_descriptor_header **); 774 775 /* build config descriptor from single descriptor vector */ 776 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 777 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 778 779 /* copy a NULL-terminated vector of descriptors */ 780 struct usb_descriptor_header **usb_copy_descriptors( 781 struct usb_descriptor_header **); 782 783 /** 784 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 785 * @v: vector of descriptors 786 */ 787 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 788 { 789 kfree(v); 790 } 791 792 struct usb_function; 793 int usb_assign_descriptors(struct usb_function *f, 794 struct usb_descriptor_header **fs, 795 struct usb_descriptor_header **hs, 796 struct usb_descriptor_header **ss, 797 struct usb_descriptor_header **ssp); 798 void usb_free_all_descriptors(struct usb_function *f); 799 800 struct usb_descriptor_header *usb_otg_descriptor_alloc( 801 struct usb_gadget *gadget); 802 int usb_otg_descriptor_init(struct usb_gadget *gadget, 803 struct usb_descriptor_header *otg_desc); 804 /*-------------------------------------------------------------------------*/ 805 806 /* utility to simplify map/unmap of usb_requests to/from DMA */ 807 808 extern int usb_gadget_map_request_by_dev(struct device *dev, 809 struct usb_request *req, int is_in); 810 extern int usb_gadget_map_request(struct usb_gadget *gadget, 811 struct usb_request *req, int is_in); 812 813 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 814 struct usb_request *req, int is_in); 815 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 816 struct usb_request *req, int is_in); 817 818 /*-------------------------------------------------------------------------*/ 819 820 /* utility to set gadget state properly */ 821 822 extern void usb_gadget_set_state(struct usb_gadget *gadget, 823 enum usb_device_state state); 824 825 /*-------------------------------------------------------------------------*/ 826 827 /* utility to tell udc core that the bus reset occurs */ 828 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 829 struct usb_gadget_driver *driver); 830 831 /*-------------------------------------------------------------------------*/ 832 833 /* utility to give requests back to the gadget layer */ 834 835 extern void usb_gadget_giveback_request(struct usb_ep *ep, 836 struct usb_request *req); 837 838 /*-------------------------------------------------------------------------*/ 839 840 /* utility to find endpoint by name */ 841 842 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 843 const char *name); 844 845 /*-------------------------------------------------------------------------*/ 846 847 /* utility to check if endpoint caps match descriptor needs */ 848 849 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 850 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 851 struct usb_ss_ep_comp_descriptor *ep_comp); 852 853 /*-------------------------------------------------------------------------*/ 854 855 /* utility to update vbus status for udc core, it may be scheduled */ 856 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 857 858 /*-------------------------------------------------------------------------*/ 859 860 /* utility wrapping a simple endpoint selection policy */ 861 862 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 863 struct usb_endpoint_descriptor *); 864 865 866 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 867 struct usb_endpoint_descriptor *, 868 struct usb_ss_ep_comp_descriptor *); 869 870 extern void usb_ep_autoconfig_release(struct usb_ep *); 871 872 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 873 874 #endif /* __LINUX_USB_GADGET_H */ 875