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 * talk to many USB gadgets, but the gadgets are only able to communicate 8 * to one host. 9 * 10 * 11 * (C) Copyright 2002-2004 by David Brownell 12 * All Rights Reserved. 13 * 14 * This software is licensed under the GNU GPL version 2. 15 */ 16 17 #ifndef __LINUX_USB_GADGET_H 18 #define __LINUX_USB_GADGET_H 19 20 #include <linux/device.h> 21 #include <linux/errno.h> 22 #include <linux/init.h> 23 #include <linux/list.h> 24 #include <linux/slab.h> 25 #include <linux/scatterlist.h> 26 #include <linux/types.h> 27 #include <linux/workqueue.h> 28 #include <linux/usb/ch9.h> 29 30 #define UDC_TRACE_STR_MAX 512 31 32 struct usb_ep; 33 34 /** 35 * struct usb_request - describes one i/o request 36 * @buf: Buffer used for data. Always provide this; some controllers 37 * only use PIO, or don't use DMA for some endpoints. 38 * @dma: DMA address corresponding to 'buf'. If you don't set this 39 * field, and the usb controller needs one, it is responsible 40 * for mapping and unmapping the buffer. 41 * @sg: a scatterlist for SG-capable controllers. 42 * @num_sgs: number of SG entries 43 * @num_mapped_sgs: number of SG entries mapped to DMA (internal) 44 * @length: Length of that data 45 * @stream_id: The stream id, when USB3.0 bulk streams are being used 46 * @is_last: Indicates if this is the last request of a stream_id before 47 * switching to a different stream (required for DWC3 controllers). 48 * @no_interrupt: If true, hints that no completion irq is needed. 49 * Helpful sometimes with deep request queues that are handled 50 * directly by DMA controllers. 51 * @zero: If true, when writing data, makes the last packet be "short" 52 * by adding a zero length packet as needed; 53 * @short_not_ok: When reading data, makes short packets be 54 * treated as errors (queue stops advancing till cleanup). 55 * @dma_mapped: Indicates if request has been mapped to DMA (internal) 56 * @complete: Function called when request completes, so this request and 57 * its buffer may be re-used. The function will always be called with 58 * interrupts disabled, and it must not sleep. 59 * Reads terminate with a short packet, or when the buffer fills, 60 * whichever comes first. When writes terminate, some data bytes 61 * will usually still be in flight (often in a hardware fifo). 62 * Errors (for reads or writes) stop the queue from advancing 63 * until the completion function returns, so that any transfers 64 * invalidated by the error may first be dequeued. 65 * @context: For use by the completion callback 66 * @list: For use by the gadget driver. 67 * @frame_number: Reports the interval number in (micro)frame in which the 68 * isochronous transfer was transmitted or received. 69 * @status: Reports completion code, zero or a negative errno. 70 * Normally, faults block the transfer queue from advancing until 71 * the completion callback returns. 72 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 73 * or when the driver disabled the endpoint. 74 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 75 * transfers) this may be less than the requested length. If the 76 * short_not_ok flag is set, short reads are treated as errors 77 * even when status otherwise indicates successful completion. 78 * Note that for writes (IN transfers) some data bytes may still 79 * reside in a device-side FIFO when the request is reported as 80 * complete. 81 * 82 * These are allocated/freed through the endpoint they're used with. The 83 * hardware's driver can add extra per-request data to the memory it returns, 84 * which often avoids separate memory allocations (potential failures), 85 * later when the request is queued. 86 * 87 * Request flags affect request handling, such as whether a zero length 88 * packet is written (the "zero" flag), whether a short read should be 89 * treated as an error (blocking request queue advance, the "short_not_ok" 90 * flag), or hinting that an interrupt is not required (the "no_interrupt" 91 * flag, for use with deep request queues). 92 * 93 * Bulk endpoints can use any size buffers, and can also be used for interrupt 94 * transfers. interrupt-only endpoints can be much less functional. 95 * 96 * NOTE: this is analogous to 'struct urb' on the host side, except that 97 * it's thinner and promotes more pre-allocation. 98 */ 99 100 struct usb_request { 101 void *buf; 102 unsigned length; 103 dma_addr_t dma; 104 105 struct scatterlist *sg; 106 unsigned num_sgs; 107 unsigned num_mapped_sgs; 108 109 unsigned stream_id:16; 110 unsigned is_last:1; 111 unsigned no_interrupt:1; 112 unsigned zero:1; 113 unsigned short_not_ok:1; 114 unsigned dma_mapped:1; 115 116 void (*complete)(struct usb_ep *ep, 117 struct usb_request *req); 118 void *context; 119 struct list_head list; 120 121 unsigned frame_number; /* ISO ONLY */ 122 123 int status; 124 unsigned actual; 125 }; 126 127 /*-------------------------------------------------------------------------*/ 128 129 /* endpoint-specific parts of the api to the usb controller hardware. 130 * unlike the urb model, (de)multiplexing layers are not required. 131 * (so this api could slash overhead if used on the host side...) 132 * 133 * note that device side usb controllers commonly differ in how many 134 * endpoints they support, as well as their capabilities. 135 */ 136 struct usb_ep_ops { 137 int (*enable) (struct usb_ep *ep, 138 const struct usb_endpoint_descriptor *desc); 139 int (*disable) (struct usb_ep *ep); 140 void (*dispose) (struct usb_ep *ep); 141 142 struct usb_request *(*alloc_request) (struct usb_ep *ep, 143 gfp_t gfp_flags); 144 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 145 146 int (*queue) (struct usb_ep *ep, struct usb_request *req, 147 gfp_t gfp_flags); 148 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 149 150 int (*set_halt) (struct usb_ep *ep, int value); 151 int (*set_wedge) (struct usb_ep *ep); 152 153 int (*fifo_status) (struct usb_ep *ep); 154 void (*fifo_flush) (struct usb_ep *ep); 155 }; 156 157 /** 158 * struct usb_ep_caps - endpoint capabilities description 159 * @type_control:Endpoint supports control type (reserved for ep0). 160 * @type_iso:Endpoint supports isochronous transfers. 161 * @type_bulk:Endpoint supports bulk transfers. 162 * @type_int:Endpoint supports interrupt transfers. 163 * @dir_in:Endpoint supports IN direction. 164 * @dir_out:Endpoint supports OUT direction. 165 */ 166 struct usb_ep_caps { 167 unsigned type_control:1; 168 unsigned type_iso:1; 169 unsigned type_bulk:1; 170 unsigned type_int:1; 171 unsigned dir_in:1; 172 unsigned dir_out:1; 173 }; 174 175 #define USB_EP_CAPS_TYPE_CONTROL 0x01 176 #define USB_EP_CAPS_TYPE_ISO 0x02 177 #define USB_EP_CAPS_TYPE_BULK 0x04 178 #define USB_EP_CAPS_TYPE_INT 0x08 179 #define USB_EP_CAPS_TYPE_ALL \ 180 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 181 #define USB_EP_CAPS_DIR_IN 0x01 182 #define USB_EP_CAPS_DIR_OUT 0x02 183 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 184 185 #define USB_EP_CAPS(_type, _dir) \ 186 { \ 187 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 188 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 189 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 190 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 191 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 192 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 193 } 194 195 /** 196 * struct usb_ep - device side representation of USB endpoint 197 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 198 * @ops: Function pointers used to access hardware-specific operations. 199 * @ep_list:the gadget's ep_list holds all of its endpoints 200 * @caps:The structure describing types and directions supported by endoint. 201 * @enabled: The current endpoint enabled/disabled state. 202 * @claimed: True if this endpoint is claimed by a function. 203 * @maxpacket:The maximum packet size used on this endpoint. The initial 204 * value can sometimes be reduced (hardware allowing), according to 205 * the endpoint descriptor used to configure the endpoint. 206 * @maxpacket_limit:The maximum packet size value which can be handled by this 207 * endpoint. It's set once by UDC driver when endpoint is initialized, and 208 * should not be changed. Should not be confused with maxpacket. 209 * @max_streams: The maximum number of streams supported 210 * by this EP (0 - 16, actual number is 2^n) 211 * @mult: multiplier, 'mult' value for SS Isoc EPs 212 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 213 * @driver_data:for use by the gadget driver. 214 * @address: used to identify the endpoint when finding descriptor that 215 * matches connection speed 216 * @desc: endpoint descriptor. This pointer is set before the endpoint is 217 * enabled and remains valid until the endpoint is disabled. 218 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 219 * descriptor that is used to configure the endpoint 220 * 221 * the bus controller driver lists all the general purpose endpoints in 222 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 223 * and is accessed only in response to a driver setup() callback. 224 */ 225 226 struct usb_ep { 227 void *driver_data; 228 229 const char *name; 230 const struct usb_ep_ops *ops; 231 struct list_head ep_list; 232 struct usb_ep_caps caps; 233 bool claimed; 234 bool enabled; 235 unsigned maxpacket:16; 236 unsigned maxpacket_limit:16; 237 unsigned max_streams:16; 238 unsigned mult:2; 239 unsigned maxburst:5; 240 u8 address; 241 const struct usb_endpoint_descriptor *desc; 242 const struct usb_ss_ep_comp_descriptor *comp_desc; 243 }; 244 245 /*-------------------------------------------------------------------------*/ 246 247 #if IS_ENABLED(CONFIG_USB_GADGET) 248 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); 249 int usb_ep_enable(struct usb_ep *ep); 250 int usb_ep_disable(struct usb_ep *ep); 251 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); 252 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); 253 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); 254 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); 255 int usb_ep_set_halt(struct usb_ep *ep); 256 int usb_ep_clear_halt(struct usb_ep *ep); 257 int usb_ep_set_wedge(struct usb_ep *ep); 258 int usb_ep_fifo_status(struct usb_ep *ep); 259 void usb_ep_fifo_flush(struct usb_ep *ep); 260 #else 261 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 262 unsigned maxpacket_limit) 263 { } 264 static inline int usb_ep_enable(struct usb_ep *ep) 265 { return 0; } 266 static inline int usb_ep_disable(struct usb_ep *ep) 267 { return 0; } 268 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 269 gfp_t gfp_flags) 270 { return NULL; } 271 static inline void usb_ep_free_request(struct usb_ep *ep, 272 struct usb_request *req) 273 { } 274 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, 275 gfp_t gfp_flags) 276 { return 0; } 277 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 278 { return 0; } 279 static inline int usb_ep_set_halt(struct usb_ep *ep) 280 { return 0; } 281 static inline int usb_ep_clear_halt(struct usb_ep *ep) 282 { return 0; } 283 static inline int usb_ep_set_wedge(struct usb_ep *ep) 284 { return 0; } 285 static inline int usb_ep_fifo_status(struct usb_ep *ep) 286 { return 0; } 287 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 288 { } 289 #endif /* USB_GADGET */ 290 291 /*-------------------------------------------------------------------------*/ 292 293 struct usb_dcd_config_params { 294 __u8 bU1devExitLat; /* U1 Device exit Latency */ 295 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 296 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 297 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 298 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */ 299 __u8 besl_deep; /* Recommended deep BESL (0-15) */ 300 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */ 301 }; 302 303 304 struct usb_gadget; 305 struct usb_gadget_driver; 306 struct usb_udc; 307 308 /* the rest of the api to the controller hardware: device operations, 309 * which don't involve endpoints (or i/o). 310 */ 311 struct usb_gadget_ops { 312 int (*get_frame)(struct usb_gadget *); 313 int (*wakeup)(struct usb_gadget *); 314 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 315 int (*vbus_session) (struct usb_gadget *, int is_active); 316 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 317 int (*pullup) (struct usb_gadget *, int is_on); 318 int (*ioctl)(struct usb_gadget *, 319 unsigned code, unsigned long param); 320 void (*get_config_params)(struct usb_gadget *, 321 struct usb_dcd_config_params *); 322 int (*udc_start)(struct usb_gadget *, 323 struct usb_gadget_driver *); 324 int (*udc_stop)(struct usb_gadget *); 325 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed); 326 struct usb_ep *(*match_ep)(struct usb_gadget *, 327 struct usb_endpoint_descriptor *, 328 struct usb_ss_ep_comp_descriptor *); 329 }; 330 331 /** 332 * struct usb_gadget - represents a usb device 333 * @work: (internal use) Workqueue to be used for sysfs_notify() 334 * @udc: struct usb_udc pointer for this gadget 335 * @ops: Function pointers used to access hardware-specific operations. 336 * @ep0: Endpoint zero, used when reading or writing responses to 337 * driver setup() requests 338 * @ep_list: List of other endpoints supported by the device. 339 * @speed: Speed of current connection to USB host. 340 * @max_speed: Maximal speed the UDC can handle. UDC must support this 341 * and all slower speeds. 342 * @state: the state we are now (attached, suspended, configured, etc) 343 * @name: Identifies the controller hardware type. Used in diagnostics 344 * and sometimes configuration. 345 * @dev: Driver model state for this abstract device. 346 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP 347 * @out_epnum: last used out ep number 348 * @in_epnum: last used in ep number 349 * @mA: last set mA value 350 * @otg_caps: OTG capabilities of this gadget. 351 * @sg_supported: true if we can handle scatter-gather 352 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 353 * gadget driver must provide a USB OTG descriptor. 354 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 355 * is in the Mini-AB jack, and HNP has been used to switch roles 356 * so that the "A" device currently acts as A-Peripheral, not A-Host. 357 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 358 * supports HNP at this port. 359 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 360 * only supports HNP on a different root port. 361 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 362 * enabled HNP support. 363 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 364 * in peripheral mode can support HNP polling. 365 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 366 * or B-Peripheral wants to take host role. 367 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 368 * MaxPacketSize. 369 * @quirk_altset_not_supp: UDC controller doesn't support alt settings. 370 * @quirk_stall_not_supp: UDC controller doesn't support stalling. 371 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP. 372 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 373 * u_ether.c to improve performance. 374 * @is_selfpowered: if the gadget is self-powered. 375 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 376 * be connected. 377 * @connected: True if gadget is connected. 378 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag 379 * indicates that it supports LPM as per the LPM ECN & errata. 380 * @irq: the interrupt number for device controller. 381 * 382 * Gadgets have a mostly-portable "gadget driver" implementing device 383 * functions, handling all usb configurations and interfaces. Gadget 384 * drivers talk to hardware-specific code indirectly, through ops vectors. 385 * That insulates the gadget driver from hardware details, and packages 386 * the hardware endpoints through generic i/o queues. The "usb_gadget" 387 * and "usb_ep" interfaces provide that insulation from the hardware. 388 * 389 * Except for the driver data, all fields in this structure are 390 * read-only to the gadget driver. That driver data is part of the 391 * "driver model" infrastructure in 2.6 (and later) kernels, and for 392 * earlier systems is grouped in a similar structure that's not known 393 * to the rest of the kernel. 394 * 395 * Values of the three OTG device feature flags are updated before the 396 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 397 * driver suspend() calls. They are valid only when is_otg, and when the 398 * device is acting as a B-Peripheral (so is_a_peripheral is false). 399 */ 400 struct usb_gadget { 401 struct work_struct work; 402 struct usb_udc *udc; 403 /* readonly to gadget driver */ 404 const struct usb_gadget_ops *ops; 405 struct usb_ep *ep0; 406 struct list_head ep_list; /* of usb_ep */ 407 enum usb_device_speed speed; 408 enum usb_device_speed max_speed; 409 enum usb_device_state state; 410 const char *name; 411 struct device dev; 412 unsigned isoch_delay; 413 unsigned out_epnum; 414 unsigned in_epnum; 415 unsigned mA; 416 struct usb_otg_caps *otg_caps; 417 418 unsigned sg_supported:1; 419 unsigned is_otg:1; 420 unsigned is_a_peripheral:1; 421 unsigned b_hnp_enable:1; 422 unsigned a_hnp_support:1; 423 unsigned a_alt_hnp_support:1; 424 unsigned hnp_polling_support:1; 425 unsigned host_request_flag:1; 426 unsigned quirk_ep_out_aligned_size:1; 427 unsigned quirk_altset_not_supp:1; 428 unsigned quirk_stall_not_supp:1; 429 unsigned quirk_zlp_not_supp:1; 430 unsigned quirk_avoids_skb_reserve:1; 431 unsigned is_selfpowered:1; 432 unsigned deactivated:1; 433 unsigned connected:1; 434 unsigned lpm_capable:1; 435 int irq; 436 }; 437 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 438 439 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 440 { dev_set_drvdata(&gadget->dev, data); } 441 static inline void *get_gadget_data(struct usb_gadget *gadget) 442 { return dev_get_drvdata(&gadget->dev); } 443 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 444 { 445 return container_of(dev, struct usb_gadget, dev); 446 } 447 448 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 449 #define gadget_for_each_ep(tmp, gadget) \ 450 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 451 452 /** 453 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 454 * @ep: the endpoint whose maxpacketsize is used to align @len 455 * @len: buffer size's length to align to @ep's maxpacketsize 456 * 457 * This helper is used to align buffer's size to an ep's maxpacketsize. 458 */ 459 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 460 { 461 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff; 462 463 return round_up(len, max_packet_size); 464 } 465 466 /** 467 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 468 * requires quirk_ep_out_aligned_size, otherwise returns len. 469 * @g: controller to check for quirk 470 * @ep: the endpoint whose maxpacketsize is used to align @len 471 * @len: buffer size's length to align to @ep's maxpacketsize 472 * 473 * This helper is used in case it's required for any reason to check and maybe 474 * align buffer's size to an ep's maxpacketsize. 475 */ 476 static inline size_t 477 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 478 { 479 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 480 } 481 482 /** 483 * gadget_is_altset_supported - return true iff the hardware supports 484 * altsettings 485 * @g: controller to check for quirk 486 */ 487 static inline int gadget_is_altset_supported(struct usb_gadget *g) 488 { 489 return !g->quirk_altset_not_supp; 490 } 491 492 /** 493 * gadget_is_stall_supported - return true iff the hardware supports stalling 494 * @g: controller to check for quirk 495 */ 496 static inline int gadget_is_stall_supported(struct usb_gadget *g) 497 { 498 return !g->quirk_stall_not_supp; 499 } 500 501 /** 502 * gadget_is_zlp_supported - return true iff the hardware supports zlp 503 * @g: controller to check for quirk 504 */ 505 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 506 { 507 return !g->quirk_zlp_not_supp; 508 } 509 510 /** 511 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 512 * skb_reserve to improve performance. 513 * @g: controller to check for quirk 514 */ 515 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 516 { 517 return g->quirk_avoids_skb_reserve; 518 } 519 520 /** 521 * gadget_is_dualspeed - return true iff the hardware handles high speed 522 * @g: controller that might support both high and full speeds 523 */ 524 static inline int gadget_is_dualspeed(struct usb_gadget *g) 525 { 526 return g->max_speed >= USB_SPEED_HIGH; 527 } 528 529 /** 530 * gadget_is_superspeed() - return true if the hardware handles superspeed 531 * @g: controller that might support superspeed 532 */ 533 static inline int gadget_is_superspeed(struct usb_gadget *g) 534 { 535 return g->max_speed >= USB_SPEED_SUPER; 536 } 537 538 /** 539 * gadget_is_superspeed_plus() - return true if the hardware handles 540 * superspeed plus 541 * @g: controller that might support superspeed plus 542 */ 543 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 544 { 545 return g->max_speed >= USB_SPEED_SUPER_PLUS; 546 } 547 548 /** 549 * gadget_is_otg - return true iff the hardware is OTG-ready 550 * @g: controller that might have a Mini-AB connector 551 * 552 * This is a runtime test, since kernels with a USB-OTG stack sometimes 553 * run on boards which only have a Mini-B (or Mini-A) connector. 554 */ 555 static inline int gadget_is_otg(struct usb_gadget *g) 556 { 557 #ifdef CONFIG_USB_OTG 558 return g->is_otg; 559 #else 560 return 0; 561 #endif 562 } 563 564 /*-------------------------------------------------------------------------*/ 565 566 #if IS_ENABLED(CONFIG_USB_GADGET) 567 int usb_gadget_frame_number(struct usb_gadget *gadget); 568 int usb_gadget_wakeup(struct usb_gadget *gadget); 569 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 570 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 571 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 572 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 573 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 574 int usb_gadget_connect(struct usb_gadget *gadget); 575 int usb_gadget_disconnect(struct usb_gadget *gadget); 576 int usb_gadget_deactivate(struct usb_gadget *gadget); 577 int usb_gadget_activate(struct usb_gadget *gadget); 578 #else 579 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 580 { return 0; } 581 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 582 { return 0; } 583 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 584 { return 0; } 585 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 586 { return 0; } 587 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 588 { return 0; } 589 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 590 { return 0; } 591 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 592 { return 0; } 593 static inline int usb_gadget_connect(struct usb_gadget *gadget) 594 { return 0; } 595 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 596 { return 0; } 597 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 598 { return 0; } 599 static inline int usb_gadget_activate(struct usb_gadget *gadget) 600 { return 0; } 601 #endif /* CONFIG_USB_GADGET */ 602 603 /*-------------------------------------------------------------------------*/ 604 605 /** 606 * struct usb_gadget_driver - driver for usb gadget devices 607 * @function: String describing the gadget's function 608 * @max_speed: Highest speed the driver handles. 609 * @setup: Invoked for ep0 control requests that aren't handled by 610 * the hardware level driver. Most calls must be handled by 611 * the gadget driver, including descriptor and configuration 612 * management. The 16 bit members of the setup data are in 613 * USB byte order. Called in_interrupt; this may not sleep. Driver 614 * queues a response to ep0, or returns negative to stall. 615 * @disconnect: Invoked after all transfers have been stopped, 616 * when the host is disconnected. May be called in_interrupt; this 617 * may not sleep. Some devices can't detect disconnect, so this might 618 * not be called except as part of controller shutdown. 619 * @bind: the driver's bind callback 620 * @unbind: Invoked when the driver is unbound from a gadget, 621 * usually from rmmod (after a disconnect is reported). 622 * Called in a context that permits sleeping. 623 * @suspend: Invoked on USB suspend. May be called in_interrupt. 624 * @resume: Invoked on USB resume. May be called in_interrupt. 625 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 626 * and should be called in_interrupt. 627 * @driver: Driver model state for this driver. 628 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 629 * this driver will be bound to any available UDC. 630 * @pending: UDC core private data used for deferred probe of this driver. 631 * @match_existing_only: If udc is not found, return an error and don't add this 632 * gadget driver to list of pending driver 633 * 634 * Devices are disabled till a gadget driver successfully bind()s, which 635 * means the driver will handle setup() requests needed to enumerate (and 636 * meet "chapter 9" requirements) then do some useful work. 637 * 638 * If gadget->is_otg is true, the gadget driver must provide an OTG 639 * descriptor during enumeration, or else fail the bind() call. In such 640 * cases, no USB traffic may flow until both bind() returns without 641 * having called usb_gadget_disconnect(), and the USB host stack has 642 * initialized. 643 * 644 * Drivers use hardware-specific knowledge to configure the usb hardware. 645 * endpoint addressing is only one of several hardware characteristics that 646 * are in descriptors the ep0 implementation returns from setup() calls. 647 * 648 * Except for ep0 implementation, most driver code shouldn't need change to 649 * run on top of different usb controllers. It'll use endpoints set up by 650 * that ep0 implementation. 651 * 652 * The usb controller driver handles a few standard usb requests. Those 653 * include set_address, and feature flags for devices, interfaces, and 654 * endpoints (the get_status, set_feature, and clear_feature requests). 655 * 656 * Accordingly, the driver's setup() callback must always implement all 657 * get_descriptor requests, returning at least a device descriptor and 658 * a configuration descriptor. Drivers must make sure the endpoint 659 * descriptors match any hardware constraints. Some hardware also constrains 660 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 661 * 662 * The driver's setup() callback must also implement set_configuration, 663 * and should also implement set_interface, get_configuration, and 664 * get_interface. Setting a configuration (or interface) is where 665 * endpoints should be activated or (config 0) shut down. 666 * 667 * (Note that only the default control endpoint is supported. Neither 668 * hosts nor devices generally support control traffic except to ep0.) 669 * 670 * Most devices will ignore USB suspend/resume operations, and so will 671 * not provide those callbacks. However, some may need to change modes 672 * when the host is not longer directing those activities. For example, 673 * local controls (buttons, dials, etc) may need to be re-enabled since 674 * the (remote) host can't do that any longer; or an error state might 675 * be cleared, to make the device behave identically whether or not 676 * power is maintained. 677 */ 678 struct usb_gadget_driver { 679 char *function; 680 enum usb_device_speed max_speed; 681 int (*bind)(struct usb_gadget *gadget, 682 struct usb_gadget_driver *driver); 683 void (*unbind)(struct usb_gadget *); 684 int (*setup)(struct usb_gadget *, 685 const struct usb_ctrlrequest *); 686 void (*disconnect)(struct usb_gadget *); 687 void (*suspend)(struct usb_gadget *); 688 void (*resume)(struct usb_gadget *); 689 void (*reset)(struct usb_gadget *); 690 691 /* FIXME support safe rmmod */ 692 struct device_driver driver; 693 694 char *udc_name; 695 struct list_head pending; 696 unsigned match_existing_only:1; 697 }; 698 699 700 701 /*-------------------------------------------------------------------------*/ 702 703 /* driver modules register and unregister, as usual. 704 * these calls must be made in a context that can sleep. 705 * 706 * these will usually be implemented directly by the hardware-dependent 707 * usb bus interface driver, which will only support a single driver. 708 */ 709 710 /** 711 * usb_gadget_probe_driver - probe a gadget driver 712 * @driver: the driver being registered 713 * Context: can sleep 714 * 715 * Call this in your gadget driver's module initialization function, 716 * to tell the underlying usb controller driver about your driver. 717 * The @bind() function will be called to bind it to a gadget before this 718 * registration call returns. It's expected that the @bind() function will 719 * be in init sections. 720 */ 721 int usb_gadget_probe_driver(struct usb_gadget_driver *driver); 722 723 /** 724 * usb_gadget_unregister_driver - unregister a gadget driver 725 * @driver:the driver being unregistered 726 * Context: can sleep 727 * 728 * Call this in your gadget driver's module cleanup function, 729 * to tell the underlying usb controller that your driver is 730 * going away. If the controller is connected to a USB host, 731 * it will first disconnect(). The driver is also requested 732 * to unbind() and clean up any device state, before this procedure 733 * finally returns. It's expected that the unbind() functions 734 * will be in exit sections, so may not be linked in some kernels. 735 */ 736 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 737 738 extern int usb_add_gadget_udc_release(struct device *parent, 739 struct usb_gadget *gadget, void (*release)(struct device *dev)); 740 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 741 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 742 extern char *usb_get_gadget_udc_name(void); 743 744 /*-------------------------------------------------------------------------*/ 745 746 /* utility to simplify dealing with string descriptors */ 747 748 /** 749 * struct usb_string - wraps a C string and its USB id 750 * @id:the (nonzero) ID for this string 751 * @s:the string, in UTF-8 encoding 752 * 753 * If you're using usb_gadget_get_string(), use this to wrap a string 754 * together with its ID. 755 */ 756 struct usb_string { 757 u8 id; 758 const char *s; 759 }; 760 761 /** 762 * struct usb_gadget_strings - a set of USB strings in a given language 763 * @language:identifies the strings' language (0x0409 for en-us) 764 * @strings:array of strings with their ids 765 * 766 * If you're using usb_gadget_get_string(), use this to wrap all the 767 * strings for a given language. 768 */ 769 struct usb_gadget_strings { 770 u16 language; /* 0x0409 for en-us */ 771 struct usb_string *strings; 772 }; 773 774 struct usb_gadget_string_container { 775 struct list_head list; 776 u8 *stash[]; 777 }; 778 779 /* put descriptor for string with that id into buf (buflen >= 256) */ 780 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf); 781 782 /* check if the given language identifier is valid */ 783 bool usb_validate_langid(u16 langid); 784 785 /*-------------------------------------------------------------------------*/ 786 787 /* utility to simplify managing config descriptors */ 788 789 /* write vector of descriptors into buffer */ 790 int usb_descriptor_fillbuf(void *, unsigned, 791 const struct usb_descriptor_header **); 792 793 /* build config descriptor from single descriptor vector */ 794 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 795 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 796 797 /* copy a NULL-terminated vector of descriptors */ 798 struct usb_descriptor_header **usb_copy_descriptors( 799 struct usb_descriptor_header **); 800 801 /** 802 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 803 * @v: vector of descriptors 804 */ 805 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 806 { 807 kfree(v); 808 } 809 810 struct usb_function; 811 int usb_assign_descriptors(struct usb_function *f, 812 struct usb_descriptor_header **fs, 813 struct usb_descriptor_header **hs, 814 struct usb_descriptor_header **ss, 815 struct usb_descriptor_header **ssp); 816 void usb_free_all_descriptors(struct usb_function *f); 817 818 struct usb_descriptor_header *usb_otg_descriptor_alloc( 819 struct usb_gadget *gadget); 820 int usb_otg_descriptor_init(struct usb_gadget *gadget, 821 struct usb_descriptor_header *otg_desc); 822 /*-------------------------------------------------------------------------*/ 823 824 /* utility to simplify map/unmap of usb_requests to/from DMA */ 825 826 #ifdef CONFIG_HAS_DMA 827 extern int usb_gadget_map_request_by_dev(struct device *dev, 828 struct usb_request *req, int is_in); 829 extern int usb_gadget_map_request(struct usb_gadget *gadget, 830 struct usb_request *req, int is_in); 831 832 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 833 struct usb_request *req, int is_in); 834 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 835 struct usb_request *req, int is_in); 836 #else /* !CONFIG_HAS_DMA */ 837 static inline int usb_gadget_map_request_by_dev(struct device *dev, 838 struct usb_request *req, int is_in) { return -ENOSYS; } 839 static inline int usb_gadget_map_request(struct usb_gadget *gadget, 840 struct usb_request *req, int is_in) { return -ENOSYS; } 841 842 static inline void usb_gadget_unmap_request_by_dev(struct device *dev, 843 struct usb_request *req, int is_in) { } 844 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget, 845 struct usb_request *req, int is_in) { } 846 #endif /* !CONFIG_HAS_DMA */ 847 848 /*-------------------------------------------------------------------------*/ 849 850 /* utility to set gadget state properly */ 851 852 extern void usb_gadget_set_state(struct usb_gadget *gadget, 853 enum usb_device_state state); 854 855 /*-------------------------------------------------------------------------*/ 856 857 /* utility to tell udc core that the bus reset occurs */ 858 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 859 struct usb_gadget_driver *driver); 860 861 /*-------------------------------------------------------------------------*/ 862 863 /* utility to give requests back to the gadget layer */ 864 865 extern void usb_gadget_giveback_request(struct usb_ep *ep, 866 struct usb_request *req); 867 868 /*-------------------------------------------------------------------------*/ 869 870 /* utility to find endpoint by name */ 871 872 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 873 const char *name); 874 875 /*-------------------------------------------------------------------------*/ 876 877 /* utility to check if endpoint caps match descriptor needs */ 878 879 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 880 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 881 struct usb_ss_ep_comp_descriptor *ep_comp); 882 883 /*-------------------------------------------------------------------------*/ 884 885 /* utility to update vbus status for udc core, it may be scheduled */ 886 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 887 888 /*-------------------------------------------------------------------------*/ 889 890 /* utility wrapping a simple endpoint selection policy */ 891 892 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 893 struct usb_endpoint_descriptor *); 894 895 896 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 897 struct usb_endpoint_descriptor *, 898 struct usb_ss_ep_comp_descriptor *); 899 900 extern void usb_ep_autoconfig_release(struct usb_ep *); 901 902 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 903 904 #endif /* __LINUX_USB_GADGET_H */ 905