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/configfs.h> 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 endpoint. 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 void (*udc_set_ssp_rate)(struct usb_gadget *gadget, 326 enum usb_ssp_rate rate); 327 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable); 328 struct usb_ep *(*match_ep)(struct usb_gadget *, 329 struct usb_endpoint_descriptor *, 330 struct usb_ss_ep_comp_descriptor *); 331 int (*check_config)(struct usb_gadget *gadget); 332 }; 333 334 /** 335 * struct usb_gadget - represents a usb device 336 * @work: (internal use) Workqueue to be used for sysfs_notify() 337 * @udc: struct usb_udc pointer for this gadget 338 * @ops: Function pointers used to access hardware-specific operations. 339 * @ep0: Endpoint zero, used when reading or writing responses to 340 * driver setup() requests 341 * @ep_list: List of other endpoints supported by the device. 342 * @speed: Speed of current connection to USB host. 343 * @max_speed: Maximal speed the UDC can handle. UDC must support this 344 * and all slower speeds. 345 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count. 346 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC 347 * can handle. The UDC must support this and all slower speeds and lower 348 * number of lanes. 349 * @state: the state we are now (attached, suspended, configured, etc) 350 * @name: Identifies the controller hardware type. Used in diagnostics 351 * and sometimes configuration. 352 * @dev: Driver model state for this abstract device. 353 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP 354 * @out_epnum: last used out ep number 355 * @in_epnum: last used in ep number 356 * @mA: last set mA value 357 * @otg_caps: OTG capabilities of this gadget. 358 * @sg_supported: true if we can handle scatter-gather 359 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the 360 * gadget driver must provide a USB OTG descriptor. 361 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable 362 * is in the Mini-AB jack, and HNP has been used to switch roles 363 * so that the "A" device currently acts as A-Peripheral, not A-Host. 364 * @a_hnp_support: OTG device feature flag, indicating that the A-Host 365 * supports HNP at this port. 366 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host 367 * only supports HNP on a different root port. 368 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host 369 * enabled HNP support. 370 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device 371 * in peripheral mode can support HNP polling. 372 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral 373 * or B-Peripheral wants to take host role. 374 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to 375 * MaxPacketSize. 376 * @quirk_altset_not_supp: UDC controller doesn't support alt settings. 377 * @quirk_stall_not_supp: UDC controller doesn't support stalling. 378 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP. 379 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in 380 * u_ether.c to improve performance. 381 * @is_selfpowered: if the gadget is self-powered. 382 * @deactivated: True if gadget is deactivated - in deactivated state it cannot 383 * be connected. 384 * @connected: True if gadget is connected. 385 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag 386 * indicates that it supports LPM as per the LPM ECN & errata. 387 * @irq: the interrupt number for device controller. 388 * @id_number: a unique ID number for ensuring that gadget names are distinct 389 * 390 * Gadgets have a mostly-portable "gadget driver" implementing device 391 * functions, handling all usb configurations and interfaces. Gadget 392 * drivers talk to hardware-specific code indirectly, through ops vectors. 393 * That insulates the gadget driver from hardware details, and packages 394 * the hardware endpoints through generic i/o queues. The "usb_gadget" 395 * and "usb_ep" interfaces provide that insulation from the hardware. 396 * 397 * Except for the driver data, all fields in this structure are 398 * read-only to the gadget driver. That driver data is part of the 399 * "driver model" infrastructure in 2.6 (and later) kernels, and for 400 * earlier systems is grouped in a similar structure that's not known 401 * to the rest of the kernel. 402 * 403 * Values of the three OTG device feature flags are updated before the 404 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before 405 * driver suspend() calls. They are valid only when is_otg, and when the 406 * device is acting as a B-Peripheral (so is_a_peripheral is false). 407 */ 408 struct usb_gadget { 409 struct work_struct work; 410 struct usb_udc *udc; 411 /* readonly to gadget driver */ 412 const struct usb_gadget_ops *ops; 413 struct usb_ep *ep0; 414 struct list_head ep_list; /* of usb_ep */ 415 enum usb_device_speed speed; 416 enum usb_device_speed max_speed; 417 418 /* USB SuperSpeed Plus only */ 419 enum usb_ssp_rate ssp_rate; 420 enum usb_ssp_rate max_ssp_rate; 421 422 enum usb_device_state state; 423 const char *name; 424 struct device dev; 425 unsigned isoch_delay; 426 unsigned out_epnum; 427 unsigned in_epnum; 428 unsigned mA; 429 struct usb_otg_caps *otg_caps; 430 431 unsigned sg_supported:1; 432 unsigned is_otg:1; 433 unsigned is_a_peripheral:1; 434 unsigned b_hnp_enable:1; 435 unsigned a_hnp_support:1; 436 unsigned a_alt_hnp_support:1; 437 unsigned hnp_polling_support:1; 438 unsigned host_request_flag:1; 439 unsigned quirk_ep_out_aligned_size:1; 440 unsigned quirk_altset_not_supp:1; 441 unsigned quirk_stall_not_supp:1; 442 unsigned quirk_zlp_not_supp:1; 443 unsigned quirk_avoids_skb_reserve:1; 444 unsigned is_selfpowered:1; 445 unsigned deactivated:1; 446 unsigned connected:1; 447 unsigned lpm_capable:1; 448 int irq; 449 int id_number; 450 }; 451 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) 452 453 /* Interface to the device model */ 454 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) 455 { dev_set_drvdata(&gadget->dev, data); } 456 static inline void *get_gadget_data(struct usb_gadget *gadget) 457 { return dev_get_drvdata(&gadget->dev); } 458 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev) 459 { 460 return container_of(dev, struct usb_gadget, dev); 461 } 462 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget) 463 { 464 get_device(&gadget->dev); 465 return gadget; 466 } 467 static inline void usb_put_gadget(struct usb_gadget *gadget) 468 { 469 put_device(&gadget->dev); 470 } 471 extern void usb_initialize_gadget(struct device *parent, 472 struct usb_gadget *gadget, void (*release)(struct device *dev)); 473 extern int usb_add_gadget(struct usb_gadget *gadget); 474 extern void usb_del_gadget(struct usb_gadget *gadget); 475 476 /* Legacy device-model interface */ 477 extern int usb_add_gadget_udc_release(struct device *parent, 478 struct usb_gadget *gadget, void (*release)(struct device *dev)); 479 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); 480 extern void usb_del_gadget_udc(struct usb_gadget *gadget); 481 extern char *usb_get_gadget_udc_name(void); 482 483 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */ 484 #define gadget_for_each_ep(tmp, gadget) \ 485 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list) 486 487 /** 488 * usb_ep_align - returns @len aligned to ep's maxpacketsize. 489 * @ep: the endpoint whose maxpacketsize is used to align @len 490 * @len: buffer size's length to align to @ep's maxpacketsize 491 * 492 * This helper is used to align buffer's size to an ep's maxpacketsize. 493 */ 494 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len) 495 { 496 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc); 497 498 return round_up(len, max_packet_size); 499 } 500 501 /** 502 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget 503 * requires quirk_ep_out_aligned_size, otherwise returns len. 504 * @g: controller to check for quirk 505 * @ep: the endpoint whose maxpacketsize is used to align @len 506 * @len: buffer size's length to align to @ep's maxpacketsize 507 * 508 * This helper is used in case it's required for any reason to check and maybe 509 * align buffer's size to an ep's maxpacketsize. 510 */ 511 static inline size_t 512 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len) 513 { 514 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len; 515 } 516 517 /** 518 * gadget_is_altset_supported - return true iff the hardware supports 519 * altsettings 520 * @g: controller to check for quirk 521 */ 522 static inline int gadget_is_altset_supported(struct usb_gadget *g) 523 { 524 return !g->quirk_altset_not_supp; 525 } 526 527 /** 528 * gadget_is_stall_supported - return true iff the hardware supports stalling 529 * @g: controller to check for quirk 530 */ 531 static inline int gadget_is_stall_supported(struct usb_gadget *g) 532 { 533 return !g->quirk_stall_not_supp; 534 } 535 536 /** 537 * gadget_is_zlp_supported - return true iff the hardware supports zlp 538 * @g: controller to check for quirk 539 */ 540 static inline int gadget_is_zlp_supported(struct usb_gadget *g) 541 { 542 return !g->quirk_zlp_not_supp; 543 } 544 545 /** 546 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid 547 * skb_reserve to improve performance. 548 * @g: controller to check for quirk 549 */ 550 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g) 551 { 552 return g->quirk_avoids_skb_reserve; 553 } 554 555 /** 556 * gadget_is_dualspeed - return true iff the hardware handles high speed 557 * @g: controller that might support both high and full speeds 558 */ 559 static inline int gadget_is_dualspeed(struct usb_gadget *g) 560 { 561 return g->max_speed >= USB_SPEED_HIGH; 562 } 563 564 /** 565 * gadget_is_superspeed() - return true if the hardware handles superspeed 566 * @g: controller that might support superspeed 567 */ 568 static inline int gadget_is_superspeed(struct usb_gadget *g) 569 { 570 return g->max_speed >= USB_SPEED_SUPER; 571 } 572 573 /** 574 * gadget_is_superspeed_plus() - return true if the hardware handles 575 * superspeed plus 576 * @g: controller that might support superspeed plus 577 */ 578 static inline int gadget_is_superspeed_plus(struct usb_gadget *g) 579 { 580 return g->max_speed >= USB_SPEED_SUPER_PLUS; 581 } 582 583 /** 584 * gadget_is_otg - return true iff the hardware is OTG-ready 585 * @g: controller that might have a Mini-AB connector 586 * 587 * This is a runtime test, since kernels with a USB-OTG stack sometimes 588 * run on boards which only have a Mini-B (or Mini-A) connector. 589 */ 590 static inline int gadget_is_otg(struct usb_gadget *g) 591 { 592 #ifdef CONFIG_USB_OTG 593 return g->is_otg; 594 #else 595 return 0; 596 #endif 597 } 598 599 /*-------------------------------------------------------------------------*/ 600 601 #if IS_ENABLED(CONFIG_USB_GADGET) 602 int usb_gadget_frame_number(struct usb_gadget *gadget); 603 int usb_gadget_wakeup(struct usb_gadget *gadget); 604 int usb_gadget_set_selfpowered(struct usb_gadget *gadget); 605 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget); 606 int usb_gadget_vbus_connect(struct usb_gadget *gadget); 607 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA); 608 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget); 609 int usb_gadget_connect(struct usb_gadget *gadget); 610 int usb_gadget_disconnect(struct usb_gadget *gadget); 611 int usb_gadget_deactivate(struct usb_gadget *gadget); 612 int usb_gadget_activate(struct usb_gadget *gadget); 613 int usb_gadget_check_config(struct usb_gadget *gadget); 614 #else 615 static inline int usb_gadget_frame_number(struct usb_gadget *gadget) 616 { return 0; } 617 static inline int usb_gadget_wakeup(struct usb_gadget *gadget) 618 { return 0; } 619 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget) 620 { return 0; } 621 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget) 622 { return 0; } 623 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget) 624 { return 0; } 625 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA) 626 { return 0; } 627 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) 628 { return 0; } 629 static inline int usb_gadget_connect(struct usb_gadget *gadget) 630 { return 0; } 631 static inline int usb_gadget_disconnect(struct usb_gadget *gadget) 632 { return 0; } 633 static inline int usb_gadget_deactivate(struct usb_gadget *gadget) 634 { return 0; } 635 static inline int usb_gadget_activate(struct usb_gadget *gadget) 636 { return 0; } 637 static inline int usb_gadget_check_config(struct usb_gadget *gadget) 638 { return 0; } 639 #endif /* CONFIG_USB_GADGET */ 640 641 /*-------------------------------------------------------------------------*/ 642 643 /** 644 * struct usb_gadget_driver - driver for usb gadget devices 645 * @function: String describing the gadget's function 646 * @max_speed: Highest speed the driver handles. 647 * @setup: Invoked for ep0 control requests that aren't handled by 648 * the hardware level driver. Most calls must be handled by 649 * the gadget driver, including descriptor and configuration 650 * management. The 16 bit members of the setup data are in 651 * USB byte order. Called in_interrupt; this may not sleep. Driver 652 * queues a response to ep0, or returns negative to stall. 653 * @disconnect: Invoked after all transfers have been stopped, 654 * when the host is disconnected. May be called in_interrupt; this 655 * may not sleep. Some devices can't detect disconnect, so this might 656 * not be called except as part of controller shutdown. 657 * @bind: the driver's bind callback 658 * @unbind: Invoked when the driver is unbound from a gadget, 659 * usually from rmmod (after a disconnect is reported). 660 * Called in a context that permits sleeping. 661 * @suspend: Invoked on USB suspend. May be called in_interrupt. 662 * @resume: Invoked on USB resume. May be called in_interrupt. 663 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers 664 * and should be called in_interrupt. 665 * @driver: Driver model state for this driver. 666 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, 667 * this driver will be bound to any available UDC. 668 * @match_existing_only: If udc is not found, return an error and fail 669 * the driver registration 670 * @is_bound: Allow a driver to be bound to only one gadget 671 * 672 * Devices are disabled till a gadget driver successfully bind()s, which 673 * means the driver will handle setup() requests needed to enumerate (and 674 * meet "chapter 9" requirements) then do some useful work. 675 * 676 * If gadget->is_otg is true, the gadget driver must provide an OTG 677 * descriptor during enumeration, or else fail the bind() call. In such 678 * cases, no USB traffic may flow until both bind() returns without 679 * having called usb_gadget_disconnect(), and the USB host stack has 680 * initialized. 681 * 682 * Drivers use hardware-specific knowledge to configure the usb hardware. 683 * endpoint addressing is only one of several hardware characteristics that 684 * are in descriptors the ep0 implementation returns from setup() calls. 685 * 686 * Except for ep0 implementation, most driver code shouldn't need change to 687 * run on top of different usb controllers. It'll use endpoints set up by 688 * that ep0 implementation. 689 * 690 * The usb controller driver handles a few standard usb requests. Those 691 * include set_address, and feature flags for devices, interfaces, and 692 * endpoints (the get_status, set_feature, and clear_feature requests). 693 * 694 * Accordingly, the driver's setup() callback must always implement all 695 * get_descriptor requests, returning at least a device descriptor and 696 * a configuration descriptor. Drivers must make sure the endpoint 697 * descriptors match any hardware constraints. Some hardware also constrains 698 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3). 699 * 700 * The driver's setup() callback must also implement set_configuration, 701 * and should also implement set_interface, get_configuration, and 702 * get_interface. Setting a configuration (or interface) is where 703 * endpoints should be activated or (config 0) shut down. 704 * 705 * (Note that only the default control endpoint is supported. Neither 706 * hosts nor devices generally support control traffic except to ep0.) 707 * 708 * Most devices will ignore USB suspend/resume operations, and so will 709 * not provide those callbacks. However, some may need to change modes 710 * when the host is not longer directing those activities. For example, 711 * local controls (buttons, dials, etc) may need to be re-enabled since 712 * the (remote) host can't do that any longer; or an error state might 713 * be cleared, to make the device behave identically whether or not 714 * power is maintained. 715 */ 716 struct usb_gadget_driver { 717 char *function; 718 enum usb_device_speed max_speed; 719 int (*bind)(struct usb_gadget *gadget, 720 struct usb_gadget_driver *driver); 721 void (*unbind)(struct usb_gadget *); 722 int (*setup)(struct usb_gadget *, 723 const struct usb_ctrlrequest *); 724 void (*disconnect)(struct usb_gadget *); 725 void (*suspend)(struct usb_gadget *); 726 void (*resume)(struct usb_gadget *); 727 void (*reset)(struct usb_gadget *); 728 729 /* FIXME support safe rmmod */ 730 struct device_driver driver; 731 732 char *udc_name; 733 unsigned match_existing_only:1; 734 bool is_bound:1; 735 }; 736 737 738 739 /*-------------------------------------------------------------------------*/ 740 741 /* driver modules register and unregister, as usual. 742 * these calls must be made in a context that can sleep. 743 * 744 * A gadget driver can be bound to only one gadget at a time. 745 */ 746 747 /** 748 * usb_gadget_register_driver_owner - register a gadget driver 749 * @driver: the driver being registered 750 * @owner: the driver module 751 * @mod_name: the driver module's build name 752 * Context: can sleep 753 * 754 * Call this in your gadget driver's module initialization function, 755 * to tell the underlying UDC controller driver about your driver. 756 * The @bind() function will be called to bind it to a gadget before this 757 * registration call returns. It's expected that the @bind() function will 758 * be in init sections. 759 * 760 * Use the macro defined below instead of calling this directly. 761 */ 762 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver, 763 struct module *owner, const char *mod_name); 764 765 /* use a define to avoid include chaining to get THIS_MODULE & friends */ 766 #define usb_gadget_register_driver(driver) \ 767 usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME) 768 769 /** 770 * usb_gadget_unregister_driver - unregister a gadget driver 771 * @driver:the driver being unregistered 772 * Context: can sleep 773 * 774 * Call this in your gadget driver's module cleanup function, 775 * to tell the underlying usb controller that your driver is 776 * going away. If the controller is connected to a USB host, 777 * it will first disconnect(). The driver is also requested 778 * to unbind() and clean up any device state, before this procedure 779 * finally returns. It's expected that the unbind() functions 780 * will be in exit sections, so may not be linked in some kernels. 781 */ 782 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); 783 784 /*-------------------------------------------------------------------------*/ 785 786 /* utility to simplify dealing with string descriptors */ 787 788 /** 789 * struct usb_string - wraps a C string and its USB id 790 * @id:the (nonzero) ID for this string 791 * @s:the string, in UTF-8 encoding 792 * 793 * If you're using usb_gadget_get_string(), use this to wrap a string 794 * together with its ID. 795 */ 796 struct usb_string { 797 u8 id; 798 const char *s; 799 }; 800 801 /** 802 * struct usb_gadget_strings - a set of USB strings in a given language 803 * @language:identifies the strings' language (0x0409 for en-us) 804 * @strings:array of strings with their ids 805 * 806 * If you're using usb_gadget_get_string(), use this to wrap all the 807 * strings for a given language. 808 */ 809 struct usb_gadget_strings { 810 u16 language; /* 0x0409 for en-us */ 811 struct usb_string *strings; 812 }; 813 814 struct usb_gadget_string_container { 815 struct list_head list; 816 u8 *stash[]; 817 }; 818 819 /* put descriptor for string with that id into buf (buflen >= 256) */ 820 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf); 821 822 /* check if the given language identifier is valid */ 823 bool usb_validate_langid(u16 langid); 824 825 struct gadget_string { 826 struct config_item item; 827 struct list_head list; 828 char string[USB_MAX_STRING_LEN]; 829 struct usb_string usb_string; 830 }; 831 832 #define to_gadget_string(str_item)\ 833 container_of(str_item, struct gadget_string, item) 834 835 /*-------------------------------------------------------------------------*/ 836 837 /* utility to simplify managing config descriptors */ 838 839 /* write vector of descriptors into buffer */ 840 int usb_descriptor_fillbuf(void *, unsigned, 841 const struct usb_descriptor_header **); 842 843 /* build config descriptor from single descriptor vector */ 844 int usb_gadget_config_buf(const struct usb_config_descriptor *config, 845 void *buf, unsigned buflen, const struct usb_descriptor_header **desc); 846 847 /* copy a NULL-terminated vector of descriptors */ 848 struct usb_descriptor_header **usb_copy_descriptors( 849 struct usb_descriptor_header **); 850 851 /** 852 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors() 853 * @v: vector of descriptors 854 */ 855 static inline void usb_free_descriptors(struct usb_descriptor_header **v) 856 { 857 kfree(v); 858 } 859 860 struct usb_function; 861 int usb_assign_descriptors(struct usb_function *f, 862 struct usb_descriptor_header **fs, 863 struct usb_descriptor_header **hs, 864 struct usb_descriptor_header **ss, 865 struct usb_descriptor_header **ssp); 866 void usb_free_all_descriptors(struct usb_function *f); 867 868 struct usb_descriptor_header *usb_otg_descriptor_alloc( 869 struct usb_gadget *gadget); 870 int usb_otg_descriptor_init(struct usb_gadget *gadget, 871 struct usb_descriptor_header *otg_desc); 872 /*-------------------------------------------------------------------------*/ 873 874 /* utility to simplify map/unmap of usb_requests to/from DMA */ 875 876 #ifdef CONFIG_HAS_DMA 877 extern int usb_gadget_map_request_by_dev(struct device *dev, 878 struct usb_request *req, int is_in); 879 extern int usb_gadget_map_request(struct usb_gadget *gadget, 880 struct usb_request *req, int is_in); 881 882 extern void usb_gadget_unmap_request_by_dev(struct device *dev, 883 struct usb_request *req, int is_in); 884 extern void usb_gadget_unmap_request(struct usb_gadget *gadget, 885 struct usb_request *req, int is_in); 886 #else /* !CONFIG_HAS_DMA */ 887 static inline int usb_gadget_map_request_by_dev(struct device *dev, 888 struct usb_request *req, int is_in) { return -ENOSYS; } 889 static inline int usb_gadget_map_request(struct usb_gadget *gadget, 890 struct usb_request *req, int is_in) { return -ENOSYS; } 891 892 static inline void usb_gadget_unmap_request_by_dev(struct device *dev, 893 struct usb_request *req, int is_in) { } 894 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget, 895 struct usb_request *req, int is_in) { } 896 #endif /* !CONFIG_HAS_DMA */ 897 898 /*-------------------------------------------------------------------------*/ 899 900 /* utility to set gadget state properly */ 901 902 extern void usb_gadget_set_state(struct usb_gadget *gadget, 903 enum usb_device_state state); 904 905 /*-------------------------------------------------------------------------*/ 906 907 /* utility to tell udc core that the bus reset occurs */ 908 extern void usb_gadget_udc_reset(struct usb_gadget *gadget, 909 struct usb_gadget_driver *driver); 910 911 /*-------------------------------------------------------------------------*/ 912 913 /* utility to give requests back to the gadget layer */ 914 915 extern void usb_gadget_giveback_request(struct usb_ep *ep, 916 struct usb_request *req); 917 918 /*-------------------------------------------------------------------------*/ 919 920 /* utility to find endpoint by name */ 921 922 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g, 923 const char *name); 924 925 /*-------------------------------------------------------------------------*/ 926 927 /* utility to check if endpoint caps match descriptor needs */ 928 929 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget, 930 struct usb_ep *ep, struct usb_endpoint_descriptor *desc, 931 struct usb_ss_ep_comp_descriptor *ep_comp); 932 933 /*-------------------------------------------------------------------------*/ 934 935 /* utility to update vbus status for udc core, it may be scheduled */ 936 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status); 937 938 /*-------------------------------------------------------------------------*/ 939 940 /* utility wrapping a simple endpoint selection policy */ 941 942 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *, 943 struct usb_endpoint_descriptor *); 944 945 946 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *, 947 struct usb_endpoint_descriptor *, 948 struct usb_ss_ep_comp_descriptor *); 949 950 extern void usb_ep_autoconfig_release(struct usb_ep *); 951 952 extern void usb_ep_autoconfig_reset(struct usb_gadget *); 953 954 #endif /* __LINUX_USB_GADGET_H */ 955