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 * @is_last: Indicates if this is the last request of a stream_id before 46 * switching to a different stream (required for DWC3 controllers). 47 * @no_interrupt: If true, hints that no completion irq is needed. 48 * Helpful sometimes with deep request queues that are handled 49 * directly by DMA controllers. 50 * @zero: If true, when writing data, makes the last packet be "short" 51 * by adding a zero length packet as needed; 52 * @short_not_ok: When reading data, makes short packets be 53 * treated as errors (queue stops advancing till cleanup). 54 * @dma_mapped: Indicates if request has been mapped to DMA (internal) 55 * @complete: Function called when request completes, so this request and 56 * its buffer may be re-used. The function will always be called with 57 * interrupts disabled, and it must not sleep. 58 * Reads terminate with a short packet, or when the buffer fills, 59 * whichever comes first. When writes terminate, some data bytes 60 * will usually still be in flight (often in a hardware fifo). 61 * Errors (for reads or writes) stop the queue from advancing 62 * until the completion function returns, so that any transfers 63 * invalidated by the error may first be dequeued. 64 * @context: For use by the completion callback 65 * @list: For use by the gadget driver. 66 * @frame_number: Reports the interval number in (micro)frame in which the 67 * isochronous transfer was transmitted or received. 68 * @status: Reports completion code, zero or a negative errno. 69 * Normally, faults block the transfer queue from advancing until 70 * the completion callback returns. 71 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 72 * or when the driver disabled the endpoint. 73 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 74 * transfers) this may be less than the requested length. If the 75 * short_not_ok flag is set, short reads are treated as errors 76 * even when status otherwise indicates successful completion. 77 * Note that for writes (IN transfers) some data bytes may still 78 * reside in a device-side FIFO when the request is reported as 79 * complete. 80 * 81 * These are allocated/freed through the endpoint they're used with. The 82 * hardware's driver can add extra per-request data to the memory it returns, 83 * which often avoids separate memory allocations (potential failures), 84 * later when the request is queued. 85 * 86 * Request flags affect request handling, such as whether a zero length 87 * packet is written (the "zero" flag), whether a short read should be 88 * treated as an error (blocking request queue advance, the "short_not_ok" 89 * flag), or hinting that an interrupt is not required (the "no_interrupt" 90 * flag, for use with deep request queues). 91 * 92 * Bulk endpoints can use any size buffers, and can also be used for interrupt 93 * transfers. interrupt-only endpoints can be much less functional. 94 * 95 * NOTE: this is analogous to 'struct urb' on the host side, except that 96 * it's thinner and promotes more pre-allocation. 97 */ 98 99 struct usb_request { 100 void *buf; 101 unsigned length; 102 dma_addr_t dma; 103 104 struct scatterlist *sg; 105 unsigned num_sgs; 106 unsigned num_mapped_sgs; 107 108 unsigned stream_id:16; 109 unsigned is_last:1; 110 unsigned no_interrupt:1; 111 unsigned zero:1; 112 unsigned short_not_ok:1; 113 unsigned dma_mapped:1; 114 115 void (*complete)(struct usb_ep *ep, 116 struct usb_request *req); 117 void *context; 118 struct list_head list; 119 120 unsigned frame_number; /* ISO ONLY */ 121 122 int status; 123 unsigned actual; 124 }; 125 126 /*-------------------------------------------------------------------------*/ 127 128 /* endpoint-specific parts of the api to the usb controller hardware. 129 * unlike the urb model, (de)multiplexing layers are not required. 130 * (so this api could slash overhead if used on the host side...) 131 * 132 * note that device side usb controllers commonly differ in how many 133 * endpoints they support, as well as their capabilities. 134 */ 135 struct usb_ep_ops { 136 int (*enable) (struct usb_ep *ep, 137 const struct usb_endpoint_descriptor *desc); 138 int (*disable) (struct usb_ep *ep); 139 void (*dispose) (struct usb_ep *ep); 140 141 struct usb_request *(*alloc_request) (struct usb_ep *ep, 142 gfp_t gfp_flags); 143 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 144 145 int (*queue) (struct usb_ep *ep, struct usb_request *req, 146 gfp_t gfp_flags); 147 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 148 149 int (*set_halt) (struct usb_ep *ep, int value); 150 int (*set_wedge) (struct usb_ep *ep); 151 152 int (*fifo_status) (struct usb_ep *ep); 153 void (*fifo_flush) (struct usb_ep *ep); 154 }; 155 156 /** 157 * struct usb_ep_caps - endpoint capabilities description 158 * @type_control:Endpoint supports control type (reserved for ep0). 159 * @type_iso:Endpoint supports isochronous transfers. 160 * @type_bulk:Endpoint supports bulk transfers. 161 * @type_int:Endpoint supports interrupt transfers. 162 * @dir_in:Endpoint supports IN direction. 163 * @dir_out:Endpoint supports OUT direction. 164 */ 165 struct usb_ep_caps { 166 unsigned type_control:1; 167 unsigned type_iso:1; 168 unsigned type_bulk:1; 169 unsigned type_int:1; 170 unsigned dir_in:1; 171 unsigned dir_out:1; 172 }; 173 174 #define USB_EP_CAPS_TYPE_CONTROL 0x01 175 #define USB_EP_CAPS_TYPE_ISO 0x02 176 #define USB_EP_CAPS_TYPE_BULK 0x04 177 #define USB_EP_CAPS_TYPE_INT 0x08 178 #define USB_EP_CAPS_TYPE_ALL \ 179 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 180 #define USB_EP_CAPS_DIR_IN 0x01 181 #define USB_EP_CAPS_DIR_OUT 0x02 182 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 183 184 #define USB_EP_CAPS(_type, _dir) \ 185 { \ 186 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 187 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 188 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 189 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 190 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 191 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 192 } 193 194 /** 195 * struct usb_ep - device side representation of USB endpoint 196 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 197 * @ops: Function pointers used to access hardware-specific operations. 198 * @ep_list:the gadget's ep_list holds all of its endpoints 199 * @caps:The structure describing types and directions supported by endoint. 200 * @enabled: The current endpoint enabled/disabled state. 201 * @claimed: True if this endpoint is claimed by a function. 202 * @maxpacket:The maximum packet size used on this endpoint. The initial 203 * value can sometimes be reduced (hardware allowing), according to 204 * the endpoint descriptor used to configure the endpoint. 205 * @maxpacket_limit:The maximum packet size value which can be handled by this 206 * endpoint. It's set once by UDC driver when endpoint is initialized, and 207 * should not be changed. Should not be confused with maxpacket. 208 * @max_streams: The maximum number of streams supported 209 * by this EP (0 - 16, actual number is 2^n) 210 * @mult: multiplier, 'mult' value for SS Isoc EPs 211 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 212 * @driver_data:for use by the gadget driver. 213 * @address: used to identify the endpoint when finding descriptor that 214 * matches connection speed 215 * @desc: endpoint descriptor. This pointer is set before the endpoint is 216 * enabled and remains valid until the endpoint is disabled. 217 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 218 * descriptor that is used to configure the endpoint 219 * 220 * the bus controller driver lists all the general purpose endpoints in 221 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 222 * and is accessed only in response to a driver setup() callback. 223 */ 224 225 struct usb_ep { 226 void *driver_data; 227 228 const char *name; 229 const struct usb_ep_ops *ops; 230 struct list_head ep_list; 231 struct usb_ep_caps caps; 232 bool claimed; 233 bool enabled; 234 unsigned maxpacket:16; 235 unsigned maxpacket_limit:16; 236 unsigned max_streams:16; 237 unsigned mult:2; 238 unsigned maxburst:5; 239 u8 address; 240 const struct usb_endpoint_descriptor *desc; 241 const struct usb_ss_ep_comp_descriptor *comp_desc; 242 }; 243 244 /*-------------------------------------------------------------------------*/ 245 246 #if IS_ENABLED(CONFIG_USB_GADGET) 247 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); 248 int usb_ep_enable(struct usb_ep *ep); 249 int usb_ep_disable(struct usb_ep *ep); 250 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); 251 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); 252 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); 253 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); 254 int usb_ep_set_halt(struct usb_ep *ep); 255 int usb_ep_clear_halt(struct usb_ep *ep); 256 int usb_ep_set_wedge(struct usb_ep *ep); 257 int usb_ep_fifo_status(struct usb_ep *ep); 258 void usb_ep_fifo_flush(struct usb_ep *ep); 259 #else 260 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 261 unsigned maxpacket_limit) 262 { } 263 static inline int usb_ep_enable(struct usb_ep *ep) 264 { return 0; } 265 static inline int usb_ep_disable(struct usb_ep *ep) 266 { return 0; } 267 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 268 gfp_t gfp_flags) 269 { return NULL; } 270 static inline void usb_ep_free_request(struct usb_ep *ep, 271 struct usb_request *req) 272 { } 273 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, 274 gfp_t gfp_flags) 275 { return 0; } 276 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 277 { return 0; } 278 static inline int usb_ep_set_halt(struct usb_ep *ep) 279 { return 0; } 280 static inline int usb_ep_clear_halt(struct usb_ep *ep) 281 { return 0; } 282 static inline int usb_ep_set_wedge(struct usb_ep *ep) 283 { return 0; } 284 static inline int usb_ep_fifo_status(struct usb_ep *ep) 285 { return 0; } 286 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 287 { } 288 #endif /* USB_GADGET */ 289 290 /*-------------------------------------------------------------------------*/ 291 292 struct usb_dcd_config_params { 293 __u8 bU1devExitLat; /* U1 Device exit Latency */ 294 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 295 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 296 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 297 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */ 298 __u8 besl_deep; /* Recommended deep BESL (0-15) */ 299 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */ 300 }; 301 302 303 struct usb_gadget; 304 struct usb_gadget_driver; 305 struct usb_udc; 306 307 /* the rest of the api to the controller hardware: device operations, 308 * which don't involve endpoints (or i/o). 309 */ 310 struct usb_gadget_ops { 311 int (*get_frame)(struct usb_gadget *); 312 int (*wakeup)(struct usb_gadget *); 313 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 314 int (*vbus_session) (struct usb_gadget *, int is_active); 315 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 316 int (*pullup) (struct usb_gadget *, int is_on); 317 int (*ioctl)(struct usb_gadget *, 318 unsigned code, unsigned long param); 319 void (*get_config_params)(struct usb_gadget *, 320 struct usb_dcd_config_params *); 321 int (*udc_start)(struct usb_gadget *, 322 struct usb_gadget_driver *); 323 int (*udc_stop)(struct usb_gadget *); 324 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed); 325 struct usb_ep *(*match_ep)(struct usb_gadget *, 326 struct usb_endpoint_descriptor *, 327 struct usb_ss_ep_comp_descriptor *); 328 }; 329 330 /** 331 * struct usb_gadget - represents a usb slave device 332 * @work: (internal use) Workqueue to be used for sysfs_notify() 333 * @udc: struct usb_udc pointer for this gadget 334 * @ops: Function pointers used to access hardware-specific operations. 335 * @ep0: Endpoint zero, used when reading or writing responses to 336 * driver setup() requests 337 * @ep_list: List of other endpoints supported by the device. 338 * @speed: Speed of current connection to USB host. 339 * @max_speed: Maximal speed the UDC can handle. UDC must support this 340 * and all slower speeds. 341 * @state: the state we are now (attached, suspended, configured, etc) 342 * @name: Identifies the controller hardware type. Used in diagnostics 343 * and sometimes configuration. 344 * @dev: Driver model state for this abstract device. 345 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP 346 * @out_epnum: last used out ep number 347 * @in_epnum: last used in ep number 348 * @mA: last set mA value 349 * @otg_caps: OTG capabilities of this gadget. 350 * @sg_supported: true if we can handle scatter-gather 351 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 352 * gadget driver must provide a USB OTG descriptor. 353 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 354 * is in the Mini-AB jack, and HNP has been used to switch roles 355 * so that the "A" device currently acts as A-Peripheral, not A-Host. 356 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 357 * supports HNP at this port. 358 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 359 * only supports HNP on a different root port. 360 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 361 * enabled HNP support. 362 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 363 * in peripheral mode can support HNP polling. 364 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 365 * or B-Peripheral wants to take host role. 366 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 367 * MaxPacketSize. 368 * @quirk_altset_not_supp: UDC controller doesn't support alt settings. 369 * @quirk_stall_not_supp: UDC controller doesn't support stalling. 370 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP. 371 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 372 * u_ether.c to improve performance. 373 * @is_selfpowered: if the gadget is self-powered. 374 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 375 * be connected. 376 * @connected: True if gadget is connected. 377 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag 378 * indicates that it supports LPM as per the LPM ECN & errata. 379 * @irq: the interrupt number for device controller. 380 * 381 * Gadgets have a mostly-portable "gadget driver" implementing device 382 * functions, handling all usb configurations and interfaces. Gadget 383 * drivers talk to hardware-specific code indirectly, through ops vectors. 384 * That insulates the gadget driver from hardware details, and packages 385 * the hardware endpoints through generic i/o queues. The "usb_gadget" 386 * and "usb_ep" interfaces provide that insulation from the hardware. 387 * 388 * Except for the driver data, all fields in this structure are 389 * read-only to the gadget driver. That driver data is part of the 390 * "driver model" infrastructure in 2.6 (and later) kernels, and for 391 * earlier systems is grouped in a similar structure that's not known 392 * to the rest of the kernel. 393 * 394 * Values of the three OTG device feature flags are updated before the 395 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 396 * driver suspend() calls. They are valid only when is_otg, and when the 397 * device is acting as a B-Peripheral (so is_a_peripheral is false). 398 */ 399 struct usb_gadget { 400 struct work_struct work; 401 struct usb_udc *udc; 402 /* readonly to gadget driver */ 403 const struct usb_gadget_ops *ops; 404 struct usb_ep *ep0; 405 struct list_head ep_list; /* of usb_ep */ 406 enum usb_device_speed speed; 407 enum usb_device_speed max_speed; 408 enum usb_device_state state; 409 const char *name; 410 struct device dev; 411 unsigned isoch_delay; 412 unsigned out_epnum; 413 unsigned in_epnum; 414 unsigned mA; 415 struct usb_otg_caps *otg_caps; 416 417 unsigned sg_supported:1; 418 unsigned is_otg:1; 419 unsigned is_a_peripheral:1; 420 unsigned b_hnp_enable:1; 421 unsigned a_hnp_support:1; 422 unsigned a_alt_hnp_support:1; 423 unsigned hnp_polling_support:1; 424 unsigned host_request_flag:1; 425 unsigned quirk_ep_out_aligned_size:1; 426 unsigned quirk_altset_not_supp:1; 427 unsigned quirk_stall_not_supp:1; 428 unsigned quirk_zlp_not_supp:1; 429 unsigned quirk_avoids_skb_reserve:1; 430 unsigned is_selfpowered:1; 431 unsigned deactivated:1; 432 unsigned connected:1; 433 unsigned lpm_capable:1; 434 int irq; 435 }; 436 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 437 438 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 439 { dev_set_drvdata(&gadget->dev, data); } 440 static inline void *get_gadget_data(struct usb_gadget *gadget) 441 { return dev_get_drvdata(&gadget->dev); } 442 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 443 { 444 return container_of(dev, struct usb_gadget, dev); 445 } 446 447 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 448 #define gadget_for_each_ep(tmp, gadget) \ 449 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 450 451 /** 452 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 453 * @ep: the endpoint whose maxpacketsize is used to align @len 454 * @len: buffer size's length to align to @ep's maxpacketsize 455 * 456 * This helper is used to align buffer's size to an ep's maxpacketsize. 457 */ 458 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 459 { 460 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff; 461 462 return round_up(len, max_packet_size); 463 } 464 465 /** 466 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 467 * requires quirk_ep_out_aligned_size, otherwise returns len. 468 * @g: controller to check for quirk 469 * @ep: the endpoint whose maxpacketsize is used to align @len 470 * @len: buffer size's length to align to @ep's maxpacketsize 471 * 472 * This helper is used in case it's required for any reason to check and maybe 473 * align buffer's size to an ep's maxpacketsize. 474 */ 475 static inline size_t 476 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 477 { 478 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 479 } 480 481 /** 482 * gadget_is_altset_supported - return true iff the hardware supports 483 * altsettings 484 * @g: controller to check for quirk 485 */ 486 static inline int gadget_is_altset_supported(struct usb_gadget *g) 487 { 488 return !g->quirk_altset_not_supp; 489 } 490 491 /** 492 * gadget_is_stall_supported - return true iff the hardware supports stalling 493 * @g: controller to check for quirk 494 */ 495 static inline int gadget_is_stall_supported(struct usb_gadget *g) 496 { 497 return !g->quirk_stall_not_supp; 498 } 499 500 /** 501 * gadget_is_zlp_supported - return true iff the hardware supports zlp 502 * @g: controller to check for quirk 503 */ 504 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 505 { 506 return !g->quirk_zlp_not_supp; 507 } 508 509 /** 510 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 511 * skb_reserve to improve performance. 512 * @g: controller to check for quirk 513 */ 514 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 515 { 516 return g->quirk_avoids_skb_reserve; 517 } 518 519 /** 520 * gadget_is_dualspeed - return true iff the hardware handles high speed 521 * @g: controller that might support both high and full speeds 522 */ 523 static inline int gadget_is_dualspeed(struct usb_gadget *g) 524 { 525 return g->max_speed >= USB_SPEED_HIGH; 526 } 527 528 /** 529 * gadget_is_superspeed() - return true if the hardware handles superspeed 530 * @g: controller that might support superspeed 531 */ 532 static inline int gadget_is_superspeed(struct usb_gadget *g) 533 { 534 return g->max_speed >= USB_SPEED_SUPER; 535 } 536 537 /** 538 * gadget_is_superspeed_plus() - return true if the hardware handles 539 * superspeed plus 540 * @g: controller that might support superspeed plus 541 */ 542 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 543 { 544 return g->max_speed >= USB_SPEED_SUPER_PLUS; 545 } 546 547 /** 548 * gadget_is_otg - return true iff the hardware is OTG-ready 549 * @g: controller that might have a Mini-AB connector 550 * 551 * This is a runtime test, since kernels with a USB-OTG stack sometimes 552 * run on boards which only have a Mini-B (or Mini-A) connector. 553 */ 554 static inline int gadget_is_otg(struct usb_gadget *g) 555 { 556 #ifdef CONFIG_USB_OTG 557 return g->is_otg; 558 #else 559 return 0; 560 #endif 561 } 562 563 /*-------------------------------------------------------------------------*/ 564 565 #if IS_ENABLED(CONFIG_USB_GADGET) 566 int usb_gadget_frame_number(struct usb_gadget *gadget); 567 int usb_gadget_wakeup(struct usb_gadget *gadget); 568 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 569 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 570 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 571 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 572 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 573 int usb_gadget_connect(struct usb_gadget *gadget); 574 int usb_gadget_disconnect(struct usb_gadget *gadget); 575 int usb_gadget_deactivate(struct usb_gadget *gadget); 576 int usb_gadget_activate(struct usb_gadget *gadget); 577 #else 578 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 579 { return 0; } 580 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 581 { return 0; } 582 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 583 { return 0; } 584 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 585 { return 0; } 586 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 587 { return 0; } 588 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 589 { return 0; } 590 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 591 { return 0; } 592 static inline int usb_gadget_connect(struct usb_gadget *gadget) 593 { return 0; } 594 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 595 { return 0; } 596 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 597 { return 0; } 598 static inline int usb_gadget_activate(struct usb_gadget *gadget) 599 { return 0; } 600 #endif /* CONFIG_USB_GADGET */ 601 602 /*-------------------------------------------------------------------------*/ 603 604 /** 605 * struct usb_gadget_driver - driver for usb 'slave' devices 606 * @function: String describing the gadget's function 607 * @max_speed: Highest speed the driver handles. 608 * @setup: Invoked for ep0 control requests that aren't handled by 609 * the hardware level driver. Most calls must be handled by 610 * the gadget driver, including descriptor and configuration 611 * management. The 16 bit members of the setup data are in 612 * USB byte order. Called in_interrupt; this may not sleep. Driver 613 * queues a response to ep0, or returns negative to stall. 614 * @disconnect: Invoked after all transfers have been stopped, 615 * when the host is disconnected. May be called in_interrupt; this 616 * may not sleep. Some devices can't detect disconnect, so this might 617 * not be called except as part of controller shutdown. 618 * @bind: the driver's bind callback 619 * @unbind: Invoked when the driver is unbound from a gadget, 620 * usually from rmmod (after a disconnect is reported). 621 * Called in a context that permits sleeping. 622 * @suspend: Invoked on USB suspend. May be called in_interrupt. 623 * @resume: Invoked on USB resume. May be called in_interrupt. 624 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 625 * and should be called in_interrupt. 626 * @driver: Driver model state for this driver. 627 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 628 * this driver will be bound to any available UDC. 629 * @pending: UDC core private data used for deferred probe of this driver. 630 * @match_existing_only: If udc is not found, return an error and don't add this 631 * gadget driver to list of pending driver 632 * 633 * Devices are disabled till a gadget driver successfully bind()s, which 634 * means the driver will handle setup() requests needed to enumerate (and 635 * meet "chapter 9" requirements) then do some useful work. 636 * 637 * If gadget->is_otg is true, the gadget driver must provide an OTG 638 * descriptor during enumeration, or else fail the bind() call. In such 639 * cases, no USB traffic may flow until both bind() returns without 640 * having called usb_gadget_disconnect(), and the USB host stack has 641 * initialized. 642 * 643 * Drivers use hardware-specific knowledge to configure the usb hardware. 644 * endpoint addressing is only one of several hardware characteristics that 645 * are in descriptors the ep0 implementation returns from setup() calls. 646 * 647 * Except for ep0 implementation, most driver code shouldn't need change to 648 * run on top of different usb controllers. It'll use endpoints set up by 649 * that ep0 implementation. 650 * 651 * The usb controller driver handles a few standard usb requests. Those 652 * include set_address, and feature flags for devices, interfaces, and 653 * endpoints (the get_status, set_feature, and clear_feature requests). 654 * 655 * Accordingly, the driver's setup() callback must always implement all 656 * get_descriptor requests, returning at least a device descriptor and 657 * a configuration descriptor. Drivers must make sure the endpoint 658 * descriptors match any hardware constraints. Some hardware also constrains 659 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 660 * 661 * The driver's setup() callback must also implement set_configuration, 662 * and should also implement set_interface, get_configuration, and 663 * get_interface. Setting a configuration (or interface) is where 664 * endpoints should be activated or (config 0) shut down. 665 * 666 * (Note that only the default control endpoint is supported. Neither 667 * hosts nor devices generally support control traffic except to ep0.) 668 * 669 * Most devices will ignore USB suspend/resume operations, and so will 670 * not provide those callbacks. However, some may need to change modes 671 * when the host is not longer directing those activities. For example, 672 * local controls (buttons, dials, etc) may need to be re-enabled since 673 * the (remote) host can't do that any longer; or an error state might 674 * be cleared, to make the device behave identically whether or not 675 * power is maintained. 676 */ 677 struct usb_gadget_driver { 678 char *function; 679 enum usb_device_speed max_speed; 680 int (*bind)(struct usb_gadget *gadget, 681 struct usb_gadget_driver *driver); 682 void (*unbind)(struct usb_gadget *); 683 int (*setup)(struct usb_gadget *, 684 const struct usb_ctrlrequest *); 685 void (*disconnect)(struct usb_gadget *); 686 void (*suspend)(struct usb_gadget *); 687 void (*resume)(struct usb_gadget *); 688 void (*reset)(struct usb_gadget *); 689 690 /* FIXME support safe rmmod */ 691 struct device_driver driver; 692 693 char *udc_name; 694 struct list_head pending; 695 unsigned match_existing_only:1; 696 }; 697 698 699 700 /*-------------------------------------------------------------------------*/ 701 702 /* driver modules register and unregister, as usual. 703 * these calls must be made in a context that can sleep. 704 * 705 * these will usually be implemented directly by the hardware-dependent 706 * usb bus interface driver, which will only support a single driver. 707 */ 708 709 /** 710 * usb_gadget_probe_driver - probe a gadget driver 711 * @driver: the driver being registered 712 * Context: can sleep 713 * 714 * Call this in your gadget driver's module initialization function, 715 * to tell the underlying usb controller driver about your driver. 716 * The @bind() function will be called to bind it to a gadget before this 717 * registration call returns. It's expected that the @bind() function will 718 * be in init sections. 719 */ 720 int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 721 722 /** 723 * usb_gadget_unregister_driver - unregister a gadget driver 724 * @driver:the driver being unregistered 725 * Context: can sleep 726 * 727 * Call this in your gadget driver's module cleanup function, 728 * to tell the underlying usb controller that your driver is 729 * going away. If the controller is connected to a USB host, 730 * it will first disconnect(). The driver is also requested 731 * to unbind() and clean up any device state, before this procedure 732 * finally returns. It's expected that the unbind() functions 733 * will in in exit sections, so may not be linked in some kernels. 734 */ 735 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 736 737 extern int usb_add_gadget_udc_release(struct device *parent, 738 struct usb_gadget *gadget, void (*release)(struct device *dev)); 739 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 740 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 741 extern char *usb_get_gadget_udc_name(void); 742 743 /*-------------------------------------------------------------------------*/ 744 745 /* utility to simplify dealing with string descriptors */ 746 747 /** 748 * struct usb_string - wraps a C string and its USB id 749 * @id:the (nonzero) ID for this string 750 * @s:the string, in UTF-8 encoding 751 * 752 * If you're using usb_gadget_get_string(), use this to wrap a string 753 * together with its ID. 754 */ 755 struct usb_string { 756 u8 id; 757 const char *s; 758 }; 759 760 /** 761 * struct usb_gadget_strings - a set of USB strings in a given language 762 * @language:identifies the strings' language (0x0409 for en-us) 763 * @strings:array of strings with their ids 764 * 765 * If you're using usb_gadget_get_string(), use this to wrap all the 766 * strings for a given language. 767 */ 768 struct usb_gadget_strings { 769 u16 language; /* 0x0409 for en-us */ 770 struct usb_string *strings; 771 }; 772 773 struct usb_gadget_string_container { 774 struct list_head list; 775 u8 *stash[]; 776 }; 777 778 /* put descriptor for string with that id into buf (buflen >= 256) */ 779 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf); 780 781 /* check if the given language identifier is valid */ 782 bool usb_validate_langid(u16 langid); 783 784 /*-------------------------------------------------------------------------*/ 785 786 /* utility to simplify managing config descriptors */ 787 788 /* write vector of descriptors into buffer */ 789 int usb_descriptor_fillbuf(void *, unsigned, 790 const struct usb_descriptor_header **); 791 792 /* build config descriptor from single descriptor vector */ 793 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 794 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 795 796 /* copy a NULL-terminated vector of descriptors */ 797 struct usb_descriptor_header **usb_copy_descriptors( 798 struct usb_descriptor_header **); 799 800 /** 801 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 802 * @v: vector of descriptors 803 */ 804 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 805 { 806 kfree(v); 807 } 808 809 struct usb_function; 810 int usb_assign_descriptors(struct usb_function *f, 811 struct usb_descriptor_header **fs, 812 struct usb_descriptor_header **hs, 813 struct usb_descriptor_header **ss, 814 struct usb_descriptor_header **ssp); 815 void usb_free_all_descriptors(struct usb_function *f); 816 817 struct usb_descriptor_header *usb_otg_descriptor_alloc( 818 struct usb_gadget *gadget); 819 int usb_otg_descriptor_init(struct usb_gadget *gadget, 820 struct usb_descriptor_header *otg_desc); 821 /*-------------------------------------------------------------------------*/ 822 823 /* utility to simplify map/unmap of usb_requests to/from DMA */ 824 825 #ifdef CONFIG_HAS_DMA 826 extern int usb_gadget_map_request_by_dev(struct device *dev, 827 struct usb_request *req, int is_in); 828 extern int usb_gadget_map_request(struct usb_gadget *gadget, 829 struct usb_request *req, int is_in); 830 831 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 832 struct usb_request *req, int is_in); 833 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 834 struct usb_request *req, int is_in); 835 #else /* !CONFIG_HAS_DMA */ 836 static inline int usb_gadget_map_request_by_dev(struct device *dev, 837 struct usb_request *req, int is_in) { return -ENOSYS; } 838 static inline int usb_gadget_map_request(struct usb_gadget *gadget, 839 struct usb_request *req, int is_in) { return -ENOSYS; } 840 841 static inline void usb_gadget_unmap_request_by_dev(struct device *dev, 842 struct usb_request *req, int is_in) { } 843 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget, 844 struct usb_request *req, int is_in) { } 845 #endif /* !CONFIG_HAS_DMA */ 846 847 /*-------------------------------------------------------------------------*/ 848 849 /* utility to set gadget state properly */ 850 851 extern void usb_gadget_set_state(struct usb_gadget *gadget, 852 enum usb_device_state state); 853 854 /*-------------------------------------------------------------------------*/ 855 856 /* utility to tell udc core that the bus reset occurs */ 857 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 858 struct usb_gadget_driver *driver); 859 860 /*-------------------------------------------------------------------------*/ 861 862 /* utility to give requests back to the gadget layer */ 863 864 extern void usb_gadget_giveback_request(struct usb_ep *ep, 865 struct usb_request *req); 866 867 /*-------------------------------------------------------------------------*/ 868 869 /* utility to find endpoint by name */ 870 871 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 872 const char *name); 873 874 /*-------------------------------------------------------------------------*/ 875 876 /* utility to check if endpoint caps match descriptor needs */ 877 878 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 879 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 880 struct usb_ss_ep_comp_descriptor *ep_comp); 881 882 /*-------------------------------------------------------------------------*/ 883 884 /* utility to update vbus status for udc core, it may be scheduled */ 885 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 886 887 /*-------------------------------------------------------------------------*/ 888 889 /* utility wrapping a simple endpoint selection policy */ 890 891 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 892 struct usb_endpoint_descriptor *); 893 894 895 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 896 struct usb_endpoint_descriptor *, 897 struct usb_ss_ep_comp_descriptor *); 898 899 extern void usb_ep_autoconfig_release(struct usb_ep *); 900 901 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 902 903 #endif /* __LINUX_USB_GADGET_H */ 904