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 15 #ifndef __LINUX_USB_GADGET_H 16 #define __LINUX_USB_GADGET_H 17 18 #include <linux/device.h> 19 #include <linux/errno.h> 20 #include <linux/init.h> 21 #include <linux/list.h> 22 #include <linux/slab.h> 23 #include <linux/scatterlist.h> 24 #include <linux/types.h> 25 #include <linux/workqueue.h> 26 #include <linux/usb/ch9.h> 27 28 #define UDC_TRACE_STR_MAX 512 29 30 struct usb_ep; 31 32 /** 33 * struct usb_request - describes one i/o request 34 * @buf: Buffer used for data. Always provide this; some controllers 35 * only use PIO, or don't use DMA for some endpoints. 36 * @dma: DMA address corresponding to 'buf'. If you don't set this 37 * field, and the usb controller needs one, it is responsible 38 * for mapping and unmapping the buffer. 39 * @sg: a scatterlist for SG-capable controllers. 40 * @num_sgs: number of SG entries 41 * @num_mapped_sgs: number of SG entries mapped to DMA (internal) 42 * @length: Length of that data 43 * @stream_id: The stream id, when USB3.0 bulk streams are being used 44 * @is_last: Indicates if this is the last request of a stream_id before 45 * switching to a different stream (required for DWC3 controllers). 46 * @no_interrupt: If true, hints that no completion irq is needed. 47 * Helpful sometimes with deep request queues that are handled 48 * directly by DMA controllers. 49 * @zero: If true, when writing data, makes the last packet be "short" 50 * by adding a zero length packet as needed; 51 * @short_not_ok: When reading data, makes short packets be 52 * treated as errors (queue stops advancing till cleanup). 53 * @dma_mapped: Indicates if request has been mapped to DMA (internal) 54 * @complete: Function called when request completes, so this request and 55 * its buffer may be re-used. The function will always be called with 56 * interrupts disabled, and it must not sleep. 57 * Reads terminate with a short packet, or when the buffer fills, 58 * whichever comes first. When writes terminate, some data bytes 59 * will usually still be in flight (often in a hardware fifo). 60 * Errors (for reads or writes) stop the queue from advancing 61 * until the completion function returns, so that any transfers 62 * invalidated by the error may first be dequeued. 63 * @context: For use by the completion callback 64 * @list: For use by the gadget driver. 65 * @frame_number: Reports the interval number in (micro)frame in which the 66 * isochronous transfer was transmitted or received. 67 * @status: Reports completion code, zero or a negative errno. 68 * Normally, faults block the transfer queue from advancing until 69 * the completion callback returns. 70 * Code "-ESHUTDOWN" indicates completion caused by device disconnect, 71 * or when the driver disabled the endpoint. 72 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT 73 * transfers) this may be less than the requested length. If the 74 * short_not_ok flag is set, short reads are treated as errors 75 * even when status otherwise indicates successful completion. 76 * Note that for writes (IN transfers) some data bytes may still 77 * reside in a device-side FIFO when the request is reported as 78 * complete. 79 * 80 * These are allocated/freed through the endpoint they're used with. The 81 * hardware's driver can add extra per-request data to the memory it returns, 82 * which often avoids separate memory allocations (potential failures), 83 * later when the request is queued. 84 * 85 * Request flags affect request handling, such as whether a zero length 86 * packet is written (the "zero" flag), whether a short read should be 87 * treated as an error (blocking request queue advance, the "short_not_ok" 88 * flag), or hinting that an interrupt is not required (the "no_interrupt" 89 * flag, for use with deep request queues). 90 * 91 * Bulk endpoints can use any size buffers, and can also be used for interrupt 92 * transfers. interrupt-only endpoints can be much less functional. 93 * 94 * NOTE: this is analogous to 'struct urb' on the host side, except that 95 * it's thinner and promotes more pre-allocation. 96 */ 97 98 struct usb_request { 99 void *buf; 100 unsigned length; 101 dma_addr_t dma; 102 103 struct scatterlist *sg; 104 unsigned num_sgs; 105 unsigned num_mapped_sgs; 106 107 unsigned stream_id:16; 108 unsigned is_last:1; 109 unsigned no_interrupt:1; 110 unsigned zero:1; 111 unsigned short_not_ok:1; 112 unsigned dma_mapped:1; 113 114 void (*complete)(struct usb_ep *ep, 115 struct usb_request *req); 116 void *context; 117 struct list_head list; 118 119 unsigned frame_number; /* ISO ONLY */ 120 121 int status; 122 unsigned actual; 123 }; 124 125 /*-------------------------------------------------------------------------*/ 126 127 /* endpoint-specific parts of the api to the usb controller hardware. 128 * unlike the urb model, (de)multiplexing layers are not required. 129 * (so this api could slash overhead if used on the host side...) 130 * 131 * note that device side usb controllers commonly differ in how many 132 * endpoints they support, as well as their capabilities. 133 */ 134 struct usb_ep_ops { 135 int (*enable) (struct usb_ep *ep, 136 const struct usb_endpoint_descriptor *desc); 137 int (*disable) (struct usb_ep *ep); 138 void (*dispose) (struct usb_ep *ep); 139 140 struct usb_request *(*alloc_request) (struct usb_ep *ep, 141 gfp_t gfp_flags); 142 void (*free_request) (struct usb_ep *ep, struct usb_request *req); 143 144 int (*queue) (struct usb_ep *ep, struct usb_request *req, 145 gfp_t gfp_flags); 146 int (*dequeue) (struct usb_ep *ep, struct usb_request *req); 147 148 int (*set_halt) (struct usb_ep *ep, int value); 149 int (*set_wedge) (struct usb_ep *ep); 150 151 int (*fifo_status) (struct usb_ep *ep); 152 void (*fifo_flush) (struct usb_ep *ep); 153 }; 154 155 /** 156 * struct usb_ep_caps - endpoint capabilities description 157 * @type_control:Endpoint supports control type (reserved for ep0). 158 * @type_iso:Endpoint supports isochronous transfers. 159 * @type_bulk:Endpoint supports bulk transfers. 160 * @type_int:Endpoint supports interrupt transfers. 161 * @dir_in:Endpoint supports IN direction. 162 * @dir_out:Endpoint supports OUT direction. 163 */ 164 struct usb_ep_caps { 165 unsigned type_control:1; 166 unsigned type_iso:1; 167 unsigned type_bulk:1; 168 unsigned type_int:1; 169 unsigned dir_in:1; 170 unsigned dir_out:1; 171 }; 172 173 #define USB_EP_CAPS_TYPE_CONTROL 0x01 174 #define USB_EP_CAPS_TYPE_ISO 0x02 175 #define USB_EP_CAPS_TYPE_BULK 0x04 176 #define USB_EP_CAPS_TYPE_INT 0x08 177 #define USB_EP_CAPS_TYPE_ALL \ 178 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT) 179 #define USB_EP_CAPS_DIR_IN 0x01 180 #define USB_EP_CAPS_DIR_OUT 0x02 181 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT) 182 183 #define USB_EP_CAPS(_type, _dir) \ 184 { \ 185 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \ 186 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \ 187 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \ 188 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \ 189 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \ 190 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \ 191 } 192 193 /** 194 * struct usb_ep - device side representation of USB endpoint 195 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk" 196 * @ops: Function pointers used to access hardware-specific operations. 197 * @ep_list:the gadget's ep_list holds all of its endpoints 198 * @caps:The structure describing types and directions supported by endpoint. 199 * @enabled: The current endpoint enabled/disabled state. 200 * @claimed: True if this endpoint is claimed by a function. 201 * @maxpacket:The maximum packet size used on this endpoint. The initial 202 * value can sometimes be reduced (hardware allowing), according to 203 * the endpoint descriptor used to configure the endpoint. 204 * @maxpacket_limit:The maximum packet size value which can be handled by this 205 * endpoint. It's set once by UDC driver when endpoint is initialized, and 206 * should not be changed. Should not be confused with maxpacket. 207 * @max_streams: The maximum number of streams supported 208 * by this EP (0 - 16, actual number is 2^n) 209 * @mult: multiplier, 'mult' value for SS Isoc EPs 210 * @maxburst: the maximum number of bursts supported by this EP (for usb3) 211 * @driver_data:for use by the gadget driver. 212 * @address: used to identify the endpoint when finding descriptor that 213 * matches connection speed 214 * @desc: endpoint descriptor. This pointer is set before the endpoint is 215 * enabled and remains valid until the endpoint is disabled. 216 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion 217 * descriptor that is used to configure the endpoint 218 * 219 * the bus controller driver lists all the general purpose endpoints in 220 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list, 221 * and is accessed only in response to a driver setup() callback. 222 */ 223 224 struct usb_ep { 225 void *driver_data; 226 227 const char *name; 228 const struct usb_ep_ops *ops; 229 struct list_head ep_list; 230 struct usb_ep_caps caps; 231 bool claimed; 232 bool enabled; 233 unsigned maxpacket:16; 234 unsigned maxpacket_limit:16; 235 unsigned max_streams:16; 236 unsigned mult:2; 237 unsigned maxburst:5; 238 u8 address; 239 const struct usb_endpoint_descriptor *desc; 240 const struct usb_ss_ep_comp_descriptor *comp_desc; 241 }; 242 243 /*-------------------------------------------------------------------------*/ 244 245 #if IS_ENABLED(CONFIG_USB_GADGET) 246 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit); 247 int usb_ep_enable(struct usb_ep *ep); 248 int usb_ep_disable(struct usb_ep *ep); 249 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags); 250 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req); 251 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags); 252 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req); 253 int usb_ep_set_halt(struct usb_ep *ep); 254 int usb_ep_clear_halt(struct usb_ep *ep); 255 int usb_ep_set_wedge(struct usb_ep *ep); 256 int usb_ep_fifo_status(struct usb_ep *ep); 257 void usb_ep_fifo_flush(struct usb_ep *ep); 258 #else 259 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep, 260 unsigned maxpacket_limit) 261 { } 262 static inline int usb_ep_enable(struct usb_ep *ep) 263 { return 0; } 264 static inline int usb_ep_disable(struct usb_ep *ep) 265 { return 0; } 266 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, 267 gfp_t gfp_flags) 268 { return NULL; } 269 static inline void usb_ep_free_request(struct usb_ep *ep, 270 struct usb_request *req) 271 { } 272 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, 273 gfp_t gfp_flags) 274 { return 0; } 275 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) 276 { return 0; } 277 static inline int usb_ep_set_halt(struct usb_ep *ep) 278 { return 0; } 279 static inline int usb_ep_clear_halt(struct usb_ep *ep) 280 { return 0; } 281 static inline int usb_ep_set_wedge(struct usb_ep *ep) 282 { return 0; } 283 static inline int usb_ep_fifo_status(struct usb_ep *ep) 284 { return 0; } 285 static inline void usb_ep_fifo_flush(struct usb_ep *ep) 286 { } 287 #endif /* USB_GADGET */ 288 289 /*-------------------------------------------------------------------------*/ 290 291 struct usb_dcd_config_params { 292 __u8 bU1devExitLat; /* U1 Device exit Latency */ 293 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */ 294 __le16 bU2DevExitLat; /* U2 Device exit Latency */ 295 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */ 296 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */ 297 __u8 besl_deep; /* Recommended deep BESL (0-15) */ 298 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */ 299 }; 300 301 302 struct usb_gadget; 303 struct usb_gadget_driver; 304 struct usb_udc; 305 306 /* the rest of the api to the controller hardware: device operations, 307 * which don't involve endpoints (or i/o). 308 */ 309 struct usb_gadget_ops { 310 int (*get_frame)(struct usb_gadget *); 311 int (*wakeup)(struct usb_gadget *); 312 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered); 313 int (*vbus_session) (struct usb_gadget *, int is_active); 314 int (*vbus_draw) (struct usb_gadget *, unsigned mA); 315 int (*pullup) (struct usb_gadget *, int is_on); 316 int (*ioctl)(struct usb_gadget *, 317 unsigned code, unsigned long param); 318 void (*get_config_params)(struct usb_gadget *, 319 struct usb_dcd_config_params *); 320 int (*udc_start)(struct usb_gadget *, 321 struct usb_gadget_driver *); 322 int (*udc_stop)(struct usb_gadget *); 323 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed); 324 void (*udc_set_ssp_rate)(struct usb_gadget *gadget, 325 enum usb_ssp_rate rate); 326 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable); 327 struct usb_ep *(*match_ep)(struct usb_gadget *, 328 struct usb_endpoint_descriptor *, 329 struct usb_ss_ep_comp_descriptor *); 330 int (*check_config)(struct usb_gadget *gadget); 331 }; 332 333 /** 334 * struct usb_gadget - represents a usb device 335 * @work: (internal use) Workqueue to be used for sysfs_notify() 336 * @udc: struct usb_udc pointer for this gadget 337 * @ops: Function pointers used to access hardware-specific operations. 338 * @ep0: Endpoint zero, used when reading or writing responses to 339 * driver setup() requests 340 * @ep_list: List of other endpoints supported by the device. 341 * @speed: Speed of current connection to USB host. 342 * @max_speed: Maximal speed the UDC can handle. UDC must support this 343 * and all slower speeds. 344 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count. 345 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC 346 * can handle. The UDC must support this and all slower speeds and lower 347 * number of lanes. 348 * @state: the state we are now (attached, suspended, configured, etc) 349 * @name: Identifies the controller hardware type. Used in diagnostics 350 * and sometimes configuration. 351 * @dev: Driver model state for this abstract device. 352 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP 353 * @out_epnum: last used out ep number 354 * @in_epnum: last used in ep number 355 * @mA: last set mA value 356 * @otg_caps: OTG capabilities of this gadget. 357 * @sg_supported: true if we can handle scatter-gather 358 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 359 * gadget driver must provide a USB OTG descriptor. 360 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 361 * is in the Mini-AB jack, and HNP has been used to switch roles 362 * so that the "A" device currently acts as A-Peripheral, not A-Host. 363 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 364 * supports HNP at this port. 365 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 366 * only supports HNP on a different root port. 367 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 368 * enabled HNP support. 369 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 370 * in peripheral mode can support HNP polling. 371 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 372 * or B-Peripheral wants to take host role. 373 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 374 * MaxPacketSize. 375 * @quirk_altset_not_supp: UDC controller doesn't support alt settings. 376 * @quirk_stall_not_supp: UDC controller doesn't support stalling. 377 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP. 378 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 379 * u_ether.c to improve performance. 380 * @is_selfpowered: if the gadget is self-powered. 381 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 382 * be connected. 383 * @connected: True if gadget is connected. 384 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag 385 * indicates that it supports LPM as per the LPM ECN & errata. 386 * @irq: the interrupt number for device controller. 387 * @id_number: a unique ID number for ensuring that gadget names are distinct 388 * 389 * Gadgets have a mostly-portable "gadget driver" implementing device 390 * functions, handling all usb configurations and interfaces. Gadget 391 * drivers talk to hardware-specific code indirectly, through ops vectors. 392 * That insulates the gadget driver from hardware details, and packages 393 * the hardware endpoints through generic i/o queues. The "usb_gadget" 394 * and "usb_ep" interfaces provide that insulation from the hardware. 395 * 396 * Except for the driver data, all fields in this structure are 397 * read-only to the gadget driver. That driver data is part of the 398 * "driver model" infrastructure in 2.6 (and later) kernels, and for 399 * earlier systems is grouped in a similar structure that's not known 400 * to the rest of the kernel. 401 * 402 * Values of the three OTG device feature flags are updated before the 403 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 404 * driver suspend() calls. They are valid only when is_otg, and when the 405 * device is acting as a B-Peripheral (so is_a_peripheral is false). 406 */ 407 struct usb_gadget { 408 struct work_struct work; 409 struct usb_udc *udc; 410 /* readonly to gadget driver */ 411 const struct usb_gadget_ops *ops; 412 struct usb_ep *ep0; 413 struct list_head ep_list; /* of usb_ep */ 414 enum usb_device_speed speed; 415 enum usb_device_speed max_speed; 416 417 /* USB SuperSpeed Plus only */ 418 enum usb_ssp_rate ssp_rate; 419 enum usb_ssp_rate max_ssp_rate; 420 421 enum usb_device_state state; 422 const char *name; 423 struct device dev; 424 unsigned isoch_delay; 425 unsigned out_epnum; 426 unsigned in_epnum; 427 unsigned mA; 428 struct usb_otg_caps *otg_caps; 429 430 unsigned sg_supported:1; 431 unsigned is_otg:1; 432 unsigned is_a_peripheral:1; 433 unsigned b_hnp_enable:1; 434 unsigned a_hnp_support:1; 435 unsigned a_alt_hnp_support:1; 436 unsigned hnp_polling_support:1; 437 unsigned host_request_flag:1; 438 unsigned quirk_ep_out_aligned_size:1; 439 unsigned quirk_altset_not_supp:1; 440 unsigned quirk_stall_not_supp:1; 441 unsigned quirk_zlp_not_supp:1; 442 unsigned quirk_avoids_skb_reserve:1; 443 unsigned is_selfpowered:1; 444 unsigned deactivated:1; 445 unsigned connected:1; 446 unsigned lpm_capable:1; 447 int irq; 448 int id_number; 449 }; 450 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 451 452 /* Interface to the device model */ 453 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 454 { dev_set_drvdata(&gadget->dev, data); } 455 static inline void *get_gadget_data(struct usb_gadget *gadget) 456 { return dev_get_drvdata(&gadget->dev); } 457 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 458 { 459 return container_of(dev, struct usb_gadget, dev); 460 } 461 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget) 462 { 463 get_device(&gadget->dev); 464 return gadget; 465 } 466 static inline void usb_put_gadget(struct usb_gadget *gadget) 467 { 468 put_device(&gadget->dev); 469 } 470 extern void usb_initialize_gadget(struct device *parent, 471 struct usb_gadget *gadget, void (*release)(struct device *dev)); 472 extern int usb_add_gadget(struct usb_gadget *gadget); 473 extern void usb_del_gadget(struct usb_gadget *gadget); 474 475 /* Legacy device-model interface */ 476 extern int usb_add_gadget_udc_release(struct device *parent, 477 struct usb_gadget *gadget, void (*release)(struct device *dev)); 478 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 479 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 480 extern char *usb_get_gadget_udc_name(void); 481 482 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 483 #define gadget_for_each_ep(tmp, gadget) \ 484 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 485 486 /** 487 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 488 * @ep: the endpoint whose maxpacketsize is used to align @len 489 * @len: buffer size's length to align to @ep's maxpacketsize 490 * 491 * This helper is used to align buffer's size to an ep's maxpacketsize. 492 */ 493 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 494 { 495 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc); 496 497 return round_up(len, max_packet_size); 498 } 499 500 /** 501 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 502 * requires quirk_ep_out_aligned_size, otherwise returns len. 503 * @g: controller to check for quirk 504 * @ep: the endpoint whose maxpacketsize is used to align @len 505 * @len: buffer size's length to align to @ep's maxpacketsize 506 * 507 * This helper is used in case it's required for any reason to check and maybe 508 * align buffer's size to an ep's maxpacketsize. 509 */ 510 static inline size_t 511 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 512 { 513 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 514 } 515 516 /** 517 * gadget_is_altset_supported - return true iff the hardware supports 518 * altsettings 519 * @g: controller to check for quirk 520 */ 521 static inline int gadget_is_altset_supported(struct usb_gadget *g) 522 { 523 return !g->quirk_altset_not_supp; 524 } 525 526 /** 527 * gadget_is_stall_supported - return true iff the hardware supports stalling 528 * @g: controller to check for quirk 529 */ 530 static inline int gadget_is_stall_supported(struct usb_gadget *g) 531 { 532 return !g->quirk_stall_not_supp; 533 } 534 535 /** 536 * gadget_is_zlp_supported - return true iff the hardware supports zlp 537 * @g: controller to check for quirk 538 */ 539 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 540 { 541 return !g->quirk_zlp_not_supp; 542 } 543 544 /** 545 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 546 * skb_reserve to improve performance. 547 * @g: controller to check for quirk 548 */ 549 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 550 { 551 return g->quirk_avoids_skb_reserve; 552 } 553 554 /** 555 * gadget_is_dualspeed - return true iff the hardware handles high speed 556 * @g: controller that might support both high and full speeds 557 */ 558 static inline int gadget_is_dualspeed(struct usb_gadget *g) 559 { 560 return g->max_speed >= USB_SPEED_HIGH; 561 } 562 563 /** 564 * gadget_is_superspeed() - return true if the hardware handles superspeed 565 * @g: controller that might support superspeed 566 */ 567 static inline int gadget_is_superspeed(struct usb_gadget *g) 568 { 569 return g->max_speed >= USB_SPEED_SUPER; 570 } 571 572 /** 573 * gadget_is_superspeed_plus() - return true if the hardware handles 574 * superspeed plus 575 * @g: controller that might support superspeed plus 576 */ 577 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 578 { 579 return g->max_speed >= USB_SPEED_SUPER_PLUS; 580 } 581 582 /** 583 * gadget_is_otg - return true iff the hardware is OTG-ready 584 * @g: controller that might have a Mini-AB connector 585 * 586 * This is a runtime test, since kernels with a USB-OTG stack sometimes 587 * run on boards which only have a Mini-B (or Mini-A) connector. 588 */ 589 static inline int gadget_is_otg(struct usb_gadget *g) 590 { 591 #ifdef CONFIG_USB_OTG 592 return g->is_otg; 593 #else 594 return 0; 595 #endif 596 } 597 598 /*-------------------------------------------------------------------------*/ 599 600 #if IS_ENABLED(CONFIG_USB_GADGET) 601 int usb_gadget_frame_number(struct usb_gadget *gadget); 602 int usb_gadget_wakeup(struct usb_gadget *gadget); 603 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 604 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 605 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 606 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 607 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 608 int usb_gadget_connect(struct usb_gadget *gadget); 609 int usb_gadget_disconnect(struct usb_gadget *gadget); 610 int usb_gadget_deactivate(struct usb_gadget *gadget); 611 int usb_gadget_activate(struct usb_gadget *gadget); 612 int usb_gadget_check_config(struct usb_gadget *gadget); 613 #else 614 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 615 { return 0; } 616 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 617 { return 0; } 618 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 619 { return 0; } 620 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 621 { return 0; } 622 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 623 { return 0; } 624 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 625 { return 0; } 626 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 627 { return 0; } 628 static inline int usb_gadget_connect(struct usb_gadget *gadget) 629 { return 0; } 630 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 631 { return 0; } 632 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 633 { return 0; } 634 static inline int usb_gadget_activate(struct usb_gadget *gadget) 635 { return 0; } 636 static inline int usb_gadget_check_config(struct usb_gadget *gadget) 637 { return 0; } 638 #endif /* CONFIG_USB_GADGET */ 639 640 /*-------------------------------------------------------------------------*/ 641 642 /** 643 * struct usb_gadget_driver - driver for usb gadget devices 644 * @function: String describing the gadget's function 645 * @max_speed: Highest speed the driver handles. 646 * @setup: Invoked for ep0 control requests that aren't handled by 647 * the hardware level driver. Most calls must be handled by 648 * the gadget driver, including descriptor and configuration 649 * management. The 16 bit members of the setup data are in 650 * USB byte order. Called in_interrupt; this may not sleep. Driver 651 * queues a response to ep0, or returns negative to stall. 652 * @disconnect: Invoked after all transfers have been stopped, 653 * when the host is disconnected. May be called in_interrupt; this 654 * may not sleep. Some devices can't detect disconnect, so this might 655 * not be called except as part of controller shutdown. 656 * @bind: the driver's bind callback 657 * @unbind: Invoked when the driver is unbound from a gadget, 658 * usually from rmmod (after a disconnect is reported). 659 * Called in a context that permits sleeping. 660 * @suspend: Invoked on USB suspend. May be called in_interrupt. 661 * @resume: Invoked on USB resume. May be called in_interrupt. 662 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 663 * and should be called in_interrupt. 664 * @driver: Driver model state for this driver. 665 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 666 * this driver will be bound to any available UDC. 667 * @match_existing_only: If udc is not found, return an error and fail 668 * the driver registration 669 * @is_bound: Allow a driver to be bound to only one gadget 670 * 671 * Devices are disabled till a gadget driver successfully bind()s, which 672 * means the driver will handle setup() requests needed to enumerate (and 673 * meet "chapter 9" requirements) then do some useful work. 674 * 675 * If gadget->is_otg is true, the gadget driver must provide an OTG 676 * descriptor during enumeration, or else fail the bind() call. In such 677 * cases, no USB traffic may flow until both bind() returns without 678 * having called usb_gadget_disconnect(), and the USB host stack has 679 * initialized. 680 * 681 * Drivers use hardware-specific knowledge to configure the usb hardware. 682 * endpoint addressing is only one of several hardware characteristics that 683 * are in descriptors the ep0 implementation returns from setup() calls. 684 * 685 * Except for ep0 implementation, most driver code shouldn't need change to 686 * run on top of different usb controllers. It'll use endpoints set up by 687 * that ep0 implementation. 688 * 689 * The usb controller driver handles a few standard usb requests. Those 690 * include set_address, and feature flags for devices, interfaces, and 691 * endpoints (the get_status, set_feature, and clear_feature requests). 692 * 693 * Accordingly, the driver's setup() callback must always implement all 694 * get_descriptor requests, returning at least a device descriptor and 695 * a configuration descriptor. Drivers must make sure the endpoint 696 * descriptors match any hardware constraints. Some hardware also constrains 697 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 698 * 699 * The driver's setup() callback must also implement set_configuration, 700 * and should also implement set_interface, get_configuration, and 701 * get_interface. Setting a configuration (or interface) is where 702 * endpoints should be activated or (config 0) shut down. 703 * 704 * (Note that only the default control endpoint is supported. Neither 705 * hosts nor devices generally support control traffic except to ep0.) 706 * 707 * Most devices will ignore USB suspend/resume operations, and so will 708 * not provide those callbacks. However, some may need to change modes 709 * when the host is not longer directing those activities. For example, 710 * local controls (buttons, dials, etc) may need to be re-enabled since 711 * the (remote) host can't do that any longer; or an error state might 712 * be cleared, to make the device behave identically whether or not 713 * power is maintained. 714 */ 715 struct usb_gadget_driver { 716 char *function; 717 enum usb_device_speed max_speed; 718 int (*bind)(struct usb_gadget *gadget, 719 struct usb_gadget_driver *driver); 720 void (*unbind)(struct usb_gadget *); 721 int (*setup)(struct usb_gadget *, 722 const struct usb_ctrlrequest *); 723 void (*disconnect)(struct usb_gadget *); 724 void (*suspend)(struct usb_gadget *); 725 void (*resume)(struct usb_gadget *); 726 void (*reset)(struct usb_gadget *); 727 728 /* FIXME support safe rmmod */ 729 struct device_driver driver; 730 731 char *udc_name; 732 unsigned match_existing_only:1; 733 bool is_bound:1; 734 }; 735 736 737 738 /*-------------------------------------------------------------------------*/ 739 740 /* driver modules register and unregister, as usual. 741 * these calls must be made in a context that can sleep. 742 * 743 * A gadget driver can be bound to only one gadget at a time. 744 */ 745 746 /** 747 * usb_gadget_register_driver_owner - register a gadget driver 748 * @driver: the driver being registered 749 * @owner: the driver module 750 * @mod_name: the driver module's build name 751 * Context: can sleep 752 * 753 * Call this in your gadget driver's module initialization function, 754 * to tell the underlying UDC controller driver about your driver. 755 * The @bind() function will be called to bind it to a gadget before this 756 * registration call returns. It's expected that the @bind() function will 757 * be in init sections. 758 * 759 * Use the macro defined below instead of calling this directly. 760 */ 761 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver, 762 struct module *owner, const char *mod_name); 763 764 /* use a define to avoid include chaining to get THIS_MODULE & friends */ 765 #define usb_gadget_register_driver(driver) \ 766 usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME) 767 768 /** 769 * usb_gadget_unregister_driver - unregister a gadget driver 770 * @driver:the driver being unregistered 771 * Context: can sleep 772 * 773 * Call this in your gadget driver's module cleanup function, 774 * to tell the underlying usb controller that your driver is 775 * going away. If the controller is connected to a USB host, 776 * it will first disconnect(). The driver is also requested 777 * to unbind() and clean up any device state, before this procedure 778 * finally returns. It's expected that the unbind() functions 779 * will be in exit sections, so may not be linked in some kernels. 780 */ 781 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 782 783 /*-------------------------------------------------------------------------*/ 784 785 /* utility to simplify dealing with string descriptors */ 786 787 /** 788 * struct usb_string - wraps a C string and its USB id 789 * @id:the (nonzero) ID for this string 790 * @s:the string, in UTF-8 encoding 791 * 792 * If you're using usb_gadget_get_string(), use this to wrap a string 793 * together with its ID. 794 */ 795 struct usb_string { 796 u8 id; 797 const char *s; 798 }; 799 800 /** 801 * struct usb_gadget_strings - a set of USB strings in a given language 802 * @language:identifies the strings' language (0x0409 for en-us) 803 * @strings:array of strings with their ids 804 * 805 * If you're using usb_gadget_get_string(), use this to wrap all the 806 * strings for a given language. 807 */ 808 struct usb_gadget_strings { 809 u16 language; /* 0x0409 for en-us */ 810 struct usb_string *strings; 811 }; 812 813 struct usb_gadget_string_container { 814 struct list_head list; 815 u8 *stash[]; 816 }; 817 818 /* put descriptor for string with that id into buf (buflen >= 256) */ 819 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf); 820 821 /* check if the given language identifier is valid */ 822 bool usb_validate_langid(u16 langid); 823 824 /*-------------------------------------------------------------------------*/ 825 826 /* utility to simplify managing config descriptors */ 827 828 /* write vector of descriptors into buffer */ 829 int usb_descriptor_fillbuf(void *, unsigned, 830 const struct usb_descriptor_header **); 831 832 /* build config descriptor from single descriptor vector */ 833 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 834 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 835 836 /* copy a NULL-terminated vector of descriptors */ 837 struct usb_descriptor_header **usb_copy_descriptors( 838 struct usb_descriptor_header **); 839 840 /** 841 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 842 * @v: vector of descriptors 843 */ 844 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 845 { 846 kfree(v); 847 } 848 849 struct usb_function; 850 int usb_assign_descriptors(struct usb_function *f, 851 struct usb_descriptor_header **fs, 852 struct usb_descriptor_header **hs, 853 struct usb_descriptor_header **ss, 854 struct usb_descriptor_header **ssp); 855 void usb_free_all_descriptors(struct usb_function *f); 856 857 struct usb_descriptor_header *usb_otg_descriptor_alloc( 858 struct usb_gadget *gadget); 859 int usb_otg_descriptor_init(struct usb_gadget *gadget, 860 struct usb_descriptor_header *otg_desc); 861 /*-------------------------------------------------------------------------*/ 862 863 /* utility to simplify map/unmap of usb_requests to/from DMA */ 864 865 #ifdef CONFIG_HAS_DMA 866 extern int usb_gadget_map_request_by_dev(struct device *dev, 867 struct usb_request *req, int is_in); 868 extern int usb_gadget_map_request(struct usb_gadget *gadget, 869 struct usb_request *req, int is_in); 870 871 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 872 struct usb_request *req, int is_in); 873 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 874 struct usb_request *req, int is_in); 875 #else /* !CONFIG_HAS_DMA */ 876 static inline int usb_gadget_map_request_by_dev(struct device *dev, 877 struct usb_request *req, int is_in) { return -ENOSYS; } 878 static inline int usb_gadget_map_request(struct usb_gadget *gadget, 879 struct usb_request *req, int is_in) { return -ENOSYS; } 880 881 static inline void usb_gadget_unmap_request_by_dev(struct device *dev, 882 struct usb_request *req, int is_in) { } 883 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget, 884 struct usb_request *req, int is_in) { } 885 #endif /* !CONFIG_HAS_DMA */ 886 887 /*-------------------------------------------------------------------------*/ 888 889 /* utility to set gadget state properly */ 890 891 extern void usb_gadget_set_state(struct usb_gadget *gadget, 892 enum usb_device_state state); 893 894 /*-------------------------------------------------------------------------*/ 895 896 /* utility to tell udc core that the bus reset occurs */ 897 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 898 struct usb_gadget_driver *driver); 899 900 /*-------------------------------------------------------------------------*/ 901 902 /* utility to give requests back to the gadget layer */ 903 904 extern void usb_gadget_giveback_request(struct usb_ep *ep, 905 struct usb_request *req); 906 907 /*-------------------------------------------------------------------------*/ 908 909 /* utility to find endpoint by name */ 910 911 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 912 const char *name); 913 914 /*-------------------------------------------------------------------------*/ 915 916 /* utility to check if endpoint caps match descriptor needs */ 917 918 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 919 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 920 struct usb_ss_ep_comp_descriptor *ep_comp); 921 922 /*-------------------------------------------------------------------------*/ 923 924 /* utility to update vbus status for udc core, it may be scheduled */ 925 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 926 927 /*-------------------------------------------------------------------------*/ 928 929 /* utility wrapping a simple endpoint selection policy */ 930 931 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 932 struct usb_endpoint_descriptor *); 933 934 935 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 936 struct usb_endpoint_descriptor *, 937 struct usb_ss_ep_comp_descriptor *); 938 939 extern void usb_ep_autoconfig_release(struct usb_ep *); 940 941 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 942 943 #endif /* __LINUX_USB_GADGET_H */ 944