gadget.h

   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/cleanup.h>
  19#include <linux/configfs.h>
  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
  32struct usb_ep;
  33
  34/**
  35 * struct usb_request - describes one i/o request
  36 * @ep: The associated endpoint set by usb_ep_alloc_request().
  37 * @buf: Buffer used for data.  Always provide this; some controllers
  38 *	only use PIO, or don't use DMA for some endpoints.
  39 * @dma: DMA address corresponding to 'buf'.  If you don't set this
  40 *	field, and the usb controller needs one, it is responsible
  41 *	for mapping and unmapping the buffer.
  42 * @sg: a scatterlist for SG-capable controllers.
  43 * @num_sgs: number of SG entries
  44 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
  45 * @length: Length of that data
  46 * @stream_id: The stream id, when USB3.0 bulk streams are being used
  47 * @is_last: Indicates if this is the last request of a stream_id before
  48 *	switching to a different stream (required for DWC3 controllers).
  49 * @no_interrupt: If true, hints that no completion irq is needed.
  50 *	Helpful sometimes with deep request queues that are handled
  51 *	directly by DMA controllers.
  52 * @zero: If true, when writing data, makes the last packet be "short"
  53 *     by adding a zero length packet as needed;
  54 * @short_not_ok: When reading data, makes short packets be
  55 *     treated as errors (queue stops advancing till cleanup).
  56 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
  57 * @sg_was_mapped: Set if the scatterlist has been mapped before the request
  58 * @complete: Function called when request completes, so this request and
  59 *	its buffer may be re-used.  The function will always be called with
  60 *	interrupts disabled, and it must not sleep.
  61 *	Reads terminate with a short packet, or when the buffer fills,
  62 *	whichever comes first.  When writes terminate, some data bytes
  63 *	will usually still be in flight (often in a hardware fifo).
  64 *	Errors (for reads or writes) stop the queue from advancing
  65 *	until the completion function returns, so that any transfers
  66 *	invalidated by the error may first be dequeued.
  67 * @context: For use by the completion callback
  68 * @list: For use by the gadget driver.
  69 * @frame_number: Reports the interval number in (micro)frame in which the
  70 *	isochronous transfer was transmitted or received.
  71 * @status: Reports completion code, zero or a negative errno.
  72 *	Normally, faults block the transfer queue from advancing until
  73 *	the completion callback returns.
  74 *	Code "-ESHUTDOWN" indicates completion caused by device disconnect,
  75 *	or when the driver disabled the endpoint.
  76 * @actual: Reports bytes transferred to/from the buffer.  For reads (OUT
  77 *	transfers) this may be less than the requested length.  If the
  78 *	short_not_ok flag is set, short reads are treated as errors
  79 *	even when status otherwise indicates successful completion.
  80 *	Note that for writes (IN transfers) some data bytes may still
  81 *	reside in a device-side FIFO when the request is reported as
  82 *	complete.
  83 *
  84 * These are allocated/freed through the endpoint they're used with.  The
  85 * hardware's driver can add extra per-request data to the memory it returns,
  86 * which often avoids separate memory allocations (potential failures),
  87 * later when the request is queued.
  88 *
  89 * Request flags affect request handling, such as whether a zero length
  90 * packet is written (the "zero" flag), whether a short read should be
  91 * treated as an error (blocking request queue advance, the "short_not_ok"
  92 * flag), or hinting that an interrupt is not required (the "no_interrupt"
  93 * flag, for use with deep request queues).
  94 *
  95 * Bulk endpoints can use any size buffers, and can also be used for interrupt
  96 * transfers. interrupt-only endpoints can be much less functional.
  97 *
  98 * NOTE:  this is analogous to 'struct urb' on the host side, except that
  99 * it's thinner and promotes more pre-allocation.
 100 */
 101
 102struct usb_request {
 103	struct usb_ep		*ep;
 104	void			*buf;
 105	unsigned		length;
 106	dma_addr_t		dma;
 107
 108	struct scatterlist	*sg;
 109	unsigned		num_sgs;
 110	unsigned		num_mapped_sgs;
 111
 112	unsigned		stream_id:16;
 113	unsigned		is_last:1;
 114	unsigned		no_interrupt:1;
 115	unsigned		zero:1;
 116	unsigned		short_not_ok:1;
 117	unsigned		dma_mapped:1;
 118	unsigned		sg_was_mapped:1;
 119
 120	void			(*complete)(struct usb_ep *ep,
 121					struct usb_request *req);
 122	void			*context;
 123	struct list_head	list;
 124
 125	unsigned		frame_number;		/* ISO ONLY */
 126
 127	int			status;
 128	unsigned		actual;
 129};
 130
 131/*-------------------------------------------------------------------------*/
 132
 133/* endpoint-specific parts of the api to the usb controller hardware.
 134 * unlike the urb model, (de)multiplexing layers are not required.
 135 * (so this api could slash overhead if used on the host side...)
 136 *
 137 * note that device side usb controllers commonly differ in how many
 138 * endpoints they support, as well as their capabilities.
 139 */
 140struct usb_ep_ops {
 141	int (*enable) (struct usb_ep *ep,
 142		const struct usb_endpoint_descriptor *desc);
 143	int (*disable) (struct usb_ep *ep);
 144	void (*dispose) (struct usb_ep *ep);
 145
 146	struct usb_request *(*alloc_request) (struct usb_ep *ep,
 147		gfp_t gfp_flags);
 148	void (*free_request) (struct usb_ep *ep, struct usb_request *req);
 149
 150	int (*queue) (struct usb_ep *ep, struct usb_request *req,
 151		gfp_t gfp_flags);
 152	int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
 153
 154	int (*set_halt) (struct usb_ep *ep, int value);
 155	int (*set_wedge) (struct usb_ep *ep);
 156
 157	int (*fifo_status) (struct usb_ep *ep);
 158	void (*fifo_flush) (struct usb_ep *ep);
 159};
 160
 161/**
 162 * struct usb_ep_caps - endpoint capabilities description
 163 * @type_control:Endpoint supports control type (reserved for ep0).
 164 * @type_iso:Endpoint supports isochronous transfers.
 165 * @type_bulk:Endpoint supports bulk transfers.
 166 * @type_int:Endpoint supports interrupt transfers.
 167 * @dir_in:Endpoint supports IN direction.
 168 * @dir_out:Endpoint supports OUT direction.
 169 */
 170struct usb_ep_caps {
 171	unsigned type_control:1;
 172	unsigned type_iso:1;
 173	unsigned type_bulk:1;
 174	unsigned type_int:1;
 175	unsigned dir_in:1;
 176	unsigned dir_out:1;
 177};
 178
 179#define USB_EP_CAPS_TYPE_CONTROL     0x01
 180#define USB_EP_CAPS_TYPE_ISO         0x02
 181#define USB_EP_CAPS_TYPE_BULK        0x04
 182#define USB_EP_CAPS_TYPE_INT         0x08
 183#define USB_EP_CAPS_TYPE_ALL \
 184	(USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
 185#define USB_EP_CAPS_DIR_IN           0x01
 186#define USB_EP_CAPS_DIR_OUT          0x02
 187#define USB_EP_CAPS_DIR_ALL  (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
 188
 189#define USB_EP_CAPS(_type, _dir) \
 190	{ \
 191		.type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
 192		.type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
 193		.type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
 194		.type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
 195		.dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
 196		.dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
 197	}
 198
 199/**
 200 * struct usb_ep - device side representation of USB endpoint
 201 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
 202 * @ops: Function pointers used to access hardware-specific operations.
 203 * @ep_list:the gadget's ep_list holds all of its endpoints
 204 * @caps:The structure describing types and directions supported by endpoint.
 205 * @enabled: The current endpoint enabled/disabled state.
 206 * @claimed: True if this endpoint is claimed by a function.
 207 * @maxpacket:The maximum packet size used on this endpoint.  The initial
 208 *	value can sometimes be reduced (hardware allowing), according to
 209 *	the endpoint descriptor used to configure the endpoint.
 210 * @maxpacket_limit:The maximum packet size value which can be handled by this
 211 *	endpoint. It's set once by UDC driver when endpoint is initialized, and
 212 *	should not be changed. Should not be confused with maxpacket.
 213 * @max_streams: The maximum number of streams supported
 214 *	by this EP (0 - 16, actual number is 2^n)
 215 * @mult: multiplier, 'mult' value for SS Isoc EPs
 216 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
 217 * @driver_data:for use by the gadget driver.
 218 * @address: used to identify the endpoint when finding descriptor that
 219 *	matches connection speed
 220 * @desc: endpoint descriptor.  This pointer is set before the endpoint is
 221 *	enabled and remains valid until the endpoint is disabled.
 222 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
 223 *	descriptor that is used to configure the endpoint
 224 *
 225 * the bus controller driver lists all the general purpose endpoints in
 226 * gadget->ep_list.  the control endpoint (gadget->ep0) is not in that list,
 227 * and is accessed only in response to a driver setup() callback.
 228 */
 229
 230struct usb_ep {
 231	void			*driver_data;
 232
 233	const char		*name;
 234	const struct usb_ep_ops	*ops;
 235	const struct usb_endpoint_descriptor	*desc;
 236	const struct usb_ss_ep_comp_descriptor	*comp_desc;
 237	struct list_head	ep_list;
 238	struct usb_ep_caps	caps;
 239	bool			claimed;
 240	bool			enabled;
 241	unsigned		mult:2;
 242	unsigned		maxburst:5;
 243	u8			address;
 244	u16			maxpacket;
 245	u16			maxpacket_limit;
 246	u16			max_streams;
 247};
 248
 249/*-------------------------------------------------------------------------*/
 250
 251#if IS_ENABLED(CONFIG_USB_GADGET)
 252void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
 253int usb_ep_enable(struct usb_ep *ep);
 254int usb_ep_disable(struct usb_ep *ep);
 255struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
 256void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
 257int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
 258int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
 259int usb_ep_set_halt(struct usb_ep *ep);
 260int usb_ep_clear_halt(struct usb_ep *ep);
 261int usb_ep_set_wedge(struct usb_ep *ep);
 262int usb_ep_fifo_status(struct usb_ep *ep);
 263void usb_ep_fifo_flush(struct usb_ep *ep);
 264#else
 265static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
 266		unsigned maxpacket_limit)
 267{ }
 268static inline int usb_ep_enable(struct usb_ep *ep)
 269{ return 0; }
 270static inline int usb_ep_disable(struct usb_ep *ep)
 271{ return 0; }
 272static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
 273		gfp_t gfp_flags)
 274{ return NULL; }
 275static inline void usb_ep_free_request(struct usb_ep *ep,
 276		struct usb_request *req)
 277{ }
 278static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
 279		gfp_t gfp_flags)
 280{ return 0; }
 281static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 282{ return 0; }
 283static inline int usb_ep_set_halt(struct usb_ep *ep)
 284{ return 0; }
 285static inline int usb_ep_clear_halt(struct usb_ep *ep)
 286{ return 0; }
 287static inline int usb_ep_set_wedge(struct usb_ep *ep)
 288{ return 0; }
 289static inline int usb_ep_fifo_status(struct usb_ep *ep)
 290{ return 0; }
 291static inline void usb_ep_fifo_flush(struct usb_ep *ep)
 292{ }
 293#endif /* USB_GADGET */
 294
 295/*-------------------------------------------------------------------------*/
 296
 297/**
 298 * free_usb_request - frees a usb_request object and its buffer
 299 * @req: the request being freed
 300 *
 301 * This helper function frees both the request's buffer and the request object
 302 * itself by calling usb_ep_free_request(). Its signature is designed to be used
 303 * with DEFINE_FREE() to enable automatic, scope-based cleanup for usb_request
 304 * pointers.
 305 */
 306static inline void free_usb_request(struct usb_request *req)
 307{
 308	if (!req)
 309		return;
 310
 311	kfree(req->buf);
 312	usb_ep_free_request(req->ep, req);
 313}
 314
 315DEFINE_FREE(free_usb_request, struct usb_request *, free_usb_request(_T))
 316
 317/*-------------------------------------------------------------------------*/
 318
 319struct usb_dcd_config_params {
 320	__u8  bU1devExitLat;	/* U1 Device exit Latency */
 321#define USB_DEFAULT_U1_DEV_EXIT_LAT	0x01	/* Less then 1 microsec */
 322	__le16 bU2DevExitLat;	/* U2 Device exit Latency */
 323#define USB_DEFAULT_U2_DEV_EXIT_LAT	0x1F4	/* Less then 500 microsec */
 324	__u8 besl_baseline;	/* Recommended baseline BESL (0-15) */
 325	__u8 besl_deep;		/* Recommended deep BESL (0-15) */
 326#define USB_DEFAULT_BESL_UNSPECIFIED	0xFF	/* No recommended value */
 327};
 328
 329
 330struct usb_gadget;
 331struct usb_gadget_driver;
 332struct usb_udc;
 333
 334/* the rest of the api to the controller hardware: device operations,
 335 * which don't involve endpoints (or i/o).
 336 */
 337struct usb_gadget_ops {
 338	int	(*get_frame)(struct usb_gadget *);
 339	int	(*wakeup)(struct usb_gadget *);
 340	int	(*func_wakeup)(struct usb_gadget *gadget, int intf_id);
 341	int	(*set_remote_wakeup)(struct usb_gadget *, int set);
 342	int	(*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
 343	int	(*vbus_session) (struct usb_gadget *, int is_active);
 344	int	(*vbus_draw) (struct usb_gadget *, unsigned mA);
 345	int	(*pullup) (struct usb_gadget *, int is_on);
 346	int	(*ioctl)(struct usb_gadget *,
 347				unsigned code, unsigned long param);
 348	void	(*get_config_params)(struct usb_gadget *,
 349				     struct usb_dcd_config_params *);
 350	int	(*udc_start)(struct usb_gadget *,
 351			struct usb_gadget_driver *);
 352	int	(*udc_stop)(struct usb_gadget *);
 353	void	(*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
 354	void	(*udc_set_ssp_rate)(struct usb_gadget *gadget,
 355			enum usb_ssp_rate rate);
 356	void	(*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
 357	struct usb_ep *(*match_ep)(struct usb_gadget *,
 358			struct usb_endpoint_descriptor *,
 359			struct usb_ss_ep_comp_descriptor *);
 360	int	(*check_config)(struct usb_gadget *gadget);
 361};
 362
 363/**
 364 * struct usb_gadget - represents a usb device
 365 * @work: (internal use) Workqueue to be used for sysfs_notify()
 366 * @udc: struct usb_udc pointer for this gadget
 367 * @ops: Function pointers used to access hardware-specific operations.
 368 * @ep0: Endpoint zero, used when reading or writing responses to
 369 *	driver setup() requests
 370 * @ep_list: List of other endpoints supported by the device.
 371 * @speed: Speed of current connection to USB host.
 372 * @max_speed: Maximal speed the UDC can handle.  UDC must support this
 373 *      and all slower speeds.
 374 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
 375 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
 376 *	can handle. The UDC must support this and all slower speeds and lower
 377 *	number of lanes.
 378 * @state: the state we are now (attached, suspended, configured, etc)
 379 * @state_lock: Spinlock protecting the `state` and `teardown` members.
 380 * @teardown: True if the device is undergoing teardown, used to prevent
 381 *	new work from being scheduled during cleanup.
 382 * @name: Identifies the controller hardware type.  Used in diagnostics
 383 *	and sometimes configuration.
 384 * @dev: Driver model state for this abstract device.
 385 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
 386 * @out_epnum: last used out ep number
 387 * @in_epnum: last used in ep number
 388 * @mA: last set mA value
 389 * @otg_caps: OTG capabilities of this gadget.
 390 * @sg_supported: true if we can handle scatter-gather
 391 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
 392 *	gadget driver must provide a USB OTG descriptor.
 393 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
 394 *	is in the Mini-AB jack, and HNP has been used to switch roles
 395 *	so that the "A" device currently acts as A-Peripheral, not A-Host.
 396 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
 397 *	supports HNP at this port.
 398 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
 399 *	only supports HNP on a different root port.
 400 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
 401 *	enabled HNP support.
 402 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
 403 *	in peripheral mode can support HNP polling.
 404 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
 405 *	or B-Peripheral wants to take host role.
 406 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
 407 *	MaxPacketSize.
 408 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
 409 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
 410 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
 411 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
 412 *	u_ether.c to improve performance.
 413 * @is_selfpowered: if the gadget is self-powered.
 414 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
 415 *	be connected.
 416 * @connected: True if gadget is connected.
 417 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
 418 *	indicates that it supports LPM as per the LPM ECN & errata.
 419 * @wakeup_capable: True if gadget is capable of sending remote wakeup.
 420 * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
 421 * @irq: the interrupt number for device controller.
 422 * @id_number: a unique ID number for ensuring that gadget names are distinct
 423 *
 424 * Gadgets have a mostly-portable "gadget driver" implementing device
 425 * functions, handling all usb configurations and interfaces.  Gadget
 426 * drivers talk to hardware-specific code indirectly, through ops vectors.
 427 * That insulates the gadget driver from hardware details, and packages
 428 * the hardware endpoints through generic i/o queues.  The "usb_gadget"
 429 * and "usb_ep" interfaces provide that insulation from the hardware.
 430 *
 431 * Except for the driver data, all fields in this structure are
 432 * read-only to the gadget driver.  That driver data is part of the
 433 * "driver model" infrastructure in 2.6 (and later) kernels, and for
 434 * earlier systems is grouped in a similar structure that's not known
 435 * to the rest of the kernel.
 436 *
 437 * Values of the three OTG device feature flags are updated before the
 438 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
 439 * driver suspend() calls.  They are valid only when is_otg, and when the
 440 * device is acting as a B-Peripheral (so is_a_peripheral is false).
 441 */
 442struct usb_gadget {
 443	struct work_struct		work;
 444	struct usb_udc			*udc;
 445	/* readonly to gadget driver */
 446	const struct usb_gadget_ops	*ops;
 447	struct usb_ep			*ep0;
 448	struct list_head		ep_list;	/* of usb_ep */
 449	enum usb_device_speed		speed;
 450	enum usb_device_speed		max_speed;
 451
 452	/* USB SuperSpeed Plus only */
 453	enum usb_ssp_rate		ssp_rate;
 454	enum usb_ssp_rate		max_ssp_rate;
 455
 456	enum usb_device_state		state;
 457	spinlock_t			state_lock;
 458	bool				teardown;
 459	const char			*name;
 460	struct device			dev;
 461	unsigned			isoch_delay;
 462	unsigned			out_epnum;
 463	unsigned			in_epnum;
 464	unsigned			mA;
 465	struct usb_otg_caps		*otg_caps;
 466
 467	unsigned			sg_supported:1;
 468	unsigned			is_otg:1;
 469	unsigned			is_a_peripheral:1;
 470	unsigned			b_hnp_enable:1;
 471	unsigned			a_hnp_support:1;
 472	unsigned			a_alt_hnp_support:1;
 473	unsigned			hnp_polling_support:1;
 474	unsigned			host_request_flag:1;
 475	unsigned			quirk_ep_out_aligned_size:1;
 476	unsigned			quirk_altset_not_supp:1;
 477	unsigned			quirk_stall_not_supp:1;
 478	unsigned			quirk_zlp_not_supp:1;
 479	unsigned			quirk_avoids_skb_reserve:1;
 480	unsigned			is_selfpowered:1;
 481	unsigned			deactivated:1;
 482	unsigned			connected:1;
 483	unsigned			lpm_capable:1;
 484	unsigned			wakeup_capable:1;
 485	unsigned			wakeup_armed:1;
 486	int				irq;
 487	int				id_number;
 488};
 489#define work_to_gadget(w)	(container_of((w), struct usb_gadget, work))
 490
 491/* Interface to the device model */
 492static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
 493	{ dev_set_drvdata(&gadget->dev, data); }
 494static inline void *get_gadget_data(struct usb_gadget *gadget)
 495	{ return dev_get_drvdata(&gadget->dev); }
 496static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
 497{
 498	return container_of(dev, struct usb_gadget, dev);
 499}
 500static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
 501{
 502	get_device(&gadget->dev);
 503	return gadget;
 504}
 505static inline void usb_put_gadget(struct usb_gadget *gadget)
 506{
 507	put_device(&gadget->dev);
 508}
 509extern void usb_initialize_gadget(struct device *parent,
 510		struct usb_gadget *gadget, void (*release)(struct device *dev));
 511extern int usb_add_gadget(struct usb_gadget *gadget);
 512extern void usb_del_gadget(struct usb_gadget *gadget);
 513
 514/* Legacy device-model interface */
 515extern int usb_add_gadget_udc_release(struct device *parent,
 516		struct usb_gadget *gadget, void (*release)(struct device *dev));
 517extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
 518extern void usb_del_gadget_udc(struct usb_gadget *gadget);
 519extern char *usb_get_gadget_udc_name(void);
 520
 521/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
 522#define gadget_for_each_ep(tmp, gadget) \
 523	list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
 524
 525/**
 526 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
 527 * @ep: the endpoint whose maxpacketsize is used to align @len
 528 * @len: buffer size's length to align to @ep's maxpacketsize
 529 *
 530 * This helper is used to align buffer's size to an ep's maxpacketsize.
 531 */
 532static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
 533{
 534	int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc);
 535
 536	return round_up(len, max_packet_size);
 537}
 538
 539/**
 540 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
 541 *	requires quirk_ep_out_aligned_size, otherwise returns len.
 542 * @g: controller to check for quirk
 543 * @ep: the endpoint whose maxpacketsize is used to align @len
 544 * @len: buffer size's length to align to @ep's maxpacketsize
 545 *
 546 * This helper is used in case it's required for any reason to check and maybe
 547 * align buffer's size to an ep's maxpacketsize.
 548 */
 549static inline size_t
 550usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
 551{
 552	return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
 553}
 554
 555/**
 556 * gadget_is_altset_supported - return true iff the hardware supports
 557 *	altsettings
 558 * @g: controller to check for quirk
 559 */
 560static inline int gadget_is_altset_supported(struct usb_gadget *g)
 561{
 562	return !g->quirk_altset_not_supp;
 563}
 564
 565/**
 566 * gadget_is_stall_supported - return true iff the hardware supports stalling
 567 * @g: controller to check for quirk
 568 */
 569static inline int gadget_is_stall_supported(struct usb_gadget *g)
 570{
 571	return !g->quirk_stall_not_supp;
 572}
 573
 574/**
 575 * gadget_is_zlp_supported - return true iff the hardware supports zlp
 576 * @g: controller to check for quirk
 577 */
 578static inline int gadget_is_zlp_supported(struct usb_gadget *g)
 579{
 580	return !g->quirk_zlp_not_supp;
 581}
 582
 583/**
 584 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
 585 *	skb_reserve to improve performance.
 586 * @g: controller to check for quirk
 587 */
 588static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
 589{
 590	return g->quirk_avoids_skb_reserve;
 591}
 592
 593/**
 594 * gadget_is_dualspeed - return true iff the hardware handles high speed
 595 * @g: controller that might support both high and full speeds
 596 */
 597static inline int gadget_is_dualspeed(struct usb_gadget *g)
 598{
 599	return g->max_speed >= USB_SPEED_HIGH;
 600}
 601
 602/**
 603 * gadget_is_superspeed() - return true if the hardware handles superspeed
 604 * @g: controller that might support superspeed
 605 */
 606static inline int gadget_is_superspeed(struct usb_gadget *g)
 607{
 608	return g->max_speed >= USB_SPEED_SUPER;
 609}
 610
 611/**
 612 * gadget_is_superspeed_plus() - return true if the hardware handles
 613 *	superspeed plus
 614 * @g: controller that might support superspeed plus
 615 */
 616static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
 617{
 618	return g->max_speed >= USB_SPEED_SUPER_PLUS;
 619}
 620
 621/**
 622 * gadget_is_otg - return true iff the hardware is OTG-ready
 623 * @g: controller that might have a Mini-AB connector
 624 *
 625 * This is a runtime test, since kernels with a USB-OTG stack sometimes
 626 * run on boards which only have a Mini-B (or Mini-A) connector.
 627 */
 628static inline int gadget_is_otg(struct usb_gadget *g)
 629{
 630#ifdef CONFIG_USB_OTG
 631	return g->is_otg;
 632#else
 633	return 0;
 634#endif
 635}
 636
 637/*-------------------------------------------------------------------------*/
 638
 639#if IS_ENABLED(CONFIG_USB_GADGET)
 640int usb_gadget_frame_number(struct usb_gadget *gadget);
 641int usb_gadget_wakeup(struct usb_gadget *gadget);
 642int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
 643int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
 644int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
 645int usb_gadget_vbus_connect(struct usb_gadget *gadget);
 646int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
 647int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
 648int usb_gadget_connect(struct usb_gadget *gadget);
 649int usb_gadget_disconnect(struct usb_gadget *gadget);
 650int usb_gadget_deactivate(struct usb_gadget *gadget);
 651int usb_gadget_activate(struct usb_gadget *gadget);
 652int usb_gadget_check_config(struct usb_gadget *gadget);
 653#else
 654static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
 655{ return 0; }
 656static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
 657{ return 0; }
 658static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
 659{ return 0; }
 660static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
 661{ return 0; }
 662static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
 663{ return 0; }
 664static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
 665{ return 0; }
 666static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
 667{ return 0; }
 668static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
 669{ return 0; }
 670static inline int usb_gadget_connect(struct usb_gadget *gadget)
 671{ return 0; }
 672static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
 673{ return 0; }
 674static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
 675{ return 0; }
 676static inline int usb_gadget_activate(struct usb_gadget *gadget)
 677{ return 0; }
 678static inline int usb_gadget_check_config(struct usb_gadget *gadget)
 679{ return 0; }
 680#endif /* CONFIG_USB_GADGET */
 681
 682/*-------------------------------------------------------------------------*/
 683
 684/**
 685 * struct usb_gadget_driver - driver for usb gadget devices
 686 * @function: String describing the gadget's function
 687 * @max_speed: Highest speed the driver handles.
 688 * @setup: Invoked for ep0 control requests that aren't handled by
 689 *	the hardware level driver. Most calls must be handled by
 690 *	the gadget driver, including descriptor and configuration
 691 *	management.  The 16 bit members of the setup data are in
 692 *	USB byte order. Called in_interrupt; this may not sleep.  Driver
 693 *	queues a response to ep0, or returns negative to stall.
 694 * @disconnect: Invoked after all transfers have been stopped,
 695 *	when the host is disconnected.  May be called in_interrupt; this
 696 *	may not sleep.  Some devices can't detect disconnect, so this might
 697 *	not be called except as part of controller shutdown.
 698 * @bind: the driver's bind callback
 699 * @unbind: Invoked when the driver is unbound from a gadget,
 700 *	usually from rmmod (after a disconnect is reported).
 701 *	Called in a context that permits sleeping.
 702 * @suspend: Invoked on USB suspend.  May be called in_interrupt.
 703 * @resume: Invoked on USB resume.  May be called in_interrupt.
 704 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
 705 *	and should be called in_interrupt.
 706 * @driver: Driver model state for this driver.
 707 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
 708 *	this driver will be bound to any available UDC.
 709 * @match_existing_only: If udc is not found, return an error and fail
 710 *	the driver registration
 711 * @is_bound: Allow a driver to be bound to only one gadget
 712 *
 713 * Devices are disabled till a gadget driver successfully bind()s, which
 714 * means the driver will handle setup() requests needed to enumerate (and
 715 * meet "chapter 9" requirements) then do some useful work.
 716 *
 717 * If gadget->is_otg is true, the gadget driver must provide an OTG
 718 * descriptor during enumeration, or else fail the bind() call.  In such
 719 * cases, no USB traffic may flow until both bind() returns without
 720 * having called usb_gadget_disconnect(), and the USB host stack has
 721 * initialized.
 722 *
 723 * Drivers use hardware-specific knowledge to configure the usb hardware.
 724 * endpoint addressing is only one of several hardware characteristics that
 725 * are in descriptors the ep0 implementation returns from setup() calls.
 726 *
 727 * Except for ep0 implementation, most driver code shouldn't need change to
 728 * run on top of different usb controllers.  It'll use endpoints set up by
 729 * that ep0 implementation.
 730 *
 731 * The usb controller driver handles a few standard usb requests.  Those
 732 * include set_address, and feature flags for devices, interfaces, and
 733 * endpoints (the get_status, set_feature, and clear_feature requests).
 734 *
 735 * Accordingly, the driver's setup() callback must always implement all
 736 * get_descriptor requests, returning at least a device descriptor and
 737 * a configuration descriptor.  Drivers must make sure the endpoint
 738 * descriptors match any hardware constraints. Some hardware also constrains
 739 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
 740 *
 741 * The driver's setup() callback must also implement set_configuration,
 742 * and should also implement set_interface, get_configuration, and
 743 * get_interface.  Setting a configuration (or interface) is where
 744 * endpoints should be activated or (config 0) shut down.
 745 *
 746 * The gadget driver's setup() callback does not have to queue a response to
 747 * ep0 within the setup() call, the driver can do it after setup() returns.
 748 * The UDC driver must wait until such a response is queued before proceeding
 749 * with the data/status stages of the control transfer.
 750 *
 751 * NOTE: Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS
 752 * being returned from the setup() callback, which is a bug. See the comment
 753 * next to USB_GADGET_DELAYED_STATUS for details.
 754 *
 755 * (Note that only the default control endpoint is supported.  Neither
 756 * hosts nor devices generally support control traffic except to ep0.)
 757 *
 758 * Most devices will ignore USB suspend/resume operations, and so will
 759 * not provide those callbacks.  However, some may need to change modes
 760 * when the host is not longer directing those activities.  For example,
 761 * local controls (buttons, dials, etc) may need to be re-enabled since
 762 * the (remote) host can't do that any longer; or an error state might
 763 * be cleared, to make the device behave identically whether or not
 764 * power is maintained.
 765 */
 766struct usb_gadget_driver {
 767	char			*function;
 768	enum usb_device_speed	max_speed;
 769	int			(*bind)(struct usb_gadget *gadget,
 770					struct usb_gadget_driver *driver);
 771	void			(*unbind)(struct usb_gadget *);
 772	int			(*setup)(struct usb_gadget *,
 773					const struct usb_ctrlrequest *);
 774	void			(*disconnect)(struct usb_gadget *);
 775	void			(*suspend)(struct usb_gadget *);
 776	void			(*resume)(struct usb_gadget *);
 777	void			(*reset)(struct usb_gadget *);
 778
 779	/* FIXME support safe rmmod */
 780	struct device_driver	driver;
 781
 782	char			*udc_name;
 783	unsigned                match_existing_only:1;
 784	bool			is_bound:1;
 785};
 786
 787
 788
 789/*-------------------------------------------------------------------------*/
 790
 791/* driver modules register and unregister, as usual.
 792 * these calls must be made in a context that can sleep.
 793 *
 794 * A gadget driver can be bound to only one gadget at a time.
 795 */
 796
 797/**
 798 * usb_gadget_register_driver_owner - register a gadget driver
 799 * @driver: the driver being registered
 800 * @owner: the driver module
 801 * @mod_name: the driver module's build name
 802 * Context: can sleep
 803 *
 804 * Call this in your gadget driver's module initialization function,
 805 * to tell the underlying UDC controller driver about your driver.
 806 * The @bind() function will be called to bind it to a gadget before this
 807 * registration call returns.  It's expected that the @bind() function will
 808 * be in init sections.
 809 *
 810 * Use the macro defined below instead of calling this directly.
 811 */
 812int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
 813		struct module *owner, const char *mod_name);
 814
 815/* use a define to avoid include chaining to get THIS_MODULE & friends */
 816#define usb_gadget_register_driver(driver) \
 817	usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME)
 818
 819/**
 820 * usb_gadget_unregister_driver - unregister a gadget driver
 821 * @driver:the driver being unregistered
 822 * Context: can sleep
 823 *
 824 * Call this in your gadget driver's module cleanup function,
 825 * to tell the underlying usb controller that your driver is
 826 * going away.  If the controller is connected to a USB host,
 827 * it will first disconnect().  The driver is also requested
 828 * to unbind() and clean up any device state, before this procedure
 829 * finally returns.  It's expected that the unbind() functions
 830 * will be in exit sections, so may not be linked in some kernels.
 831 */
 832int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
 833
 834/*-------------------------------------------------------------------------*/
 835
 836/* utility to simplify dealing with string descriptors */
 837
 838/**
 839 * struct usb_string - wraps a C string and its USB id
 840 * @id:the (nonzero) ID for this string
 841 * @s:the string, in UTF-8 encoding
 842 *
 843 * If you're using usb_gadget_get_string(), use this to wrap a string
 844 * together with its ID.
 845 */
 846struct usb_string {
 847	u8			id;
 848	const char		*s;
 849};
 850
 851/**
 852 * struct usb_gadget_strings - a set of USB strings in a given language
 853 * @language:identifies the strings' language (0x0409 for en-us)
 854 * @strings:array of strings with their ids
 855 *
 856 * If you're using usb_gadget_get_string(), use this to wrap all the
 857 * strings for a given language.
 858 */
 859struct usb_gadget_strings {
 860	u16			language;	/* 0x0409 for en-us */
 861	struct usb_string	*strings;
 862};
 863
 864struct usb_gadget_string_container {
 865	struct list_head        list;
 866	u8                      *stash[];
 867};
 868
 869/* put descriptor for string with that id into buf (buflen >= 256) */
 870int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
 871
 872/* check if the given language identifier is valid */
 873bool usb_validate_langid(u16 langid);
 874
 875struct gadget_string {
 876	struct config_item item;
 877	struct list_head list;
 878	char string[USB_MAX_STRING_LEN];
 879	struct usb_string usb_string;
 880};
 881
 882#define to_gadget_string(str_item)\
 883container_of(str_item, struct gadget_string, item)
 884
 885/*-------------------------------------------------------------------------*/
 886
 887/* utility to simplify managing config descriptors */
 888
 889/* write vector of descriptors into buffer */
 890int usb_descriptor_fillbuf(void *, unsigned,
 891		const struct usb_descriptor_header **);
 892
 893/* copy a NULL-terminated vector of descriptors */
 894struct usb_descriptor_header **usb_copy_descriptors(
 895		struct usb_descriptor_header **);
 896
 897/**
 898 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
 899 * @v: vector of descriptors
 900 */
 901static inline void usb_free_descriptors(struct usb_descriptor_header **v)
 902{
 903	kfree(v);
 904}
 905
 906struct usb_function;
 907int usb_assign_descriptors(struct usb_function *f,
 908		struct usb_descriptor_header **fs,
 909		struct usb_descriptor_header **hs,
 910		struct usb_descriptor_header **ss,
 911		struct usb_descriptor_header **ssp);
 912void usb_free_all_descriptors(struct usb_function *f);
 913
 914struct usb_descriptor_header *usb_otg_descriptor_alloc(
 915				struct usb_gadget *gadget);
 916int usb_otg_descriptor_init(struct usb_gadget *gadget,
 917		struct usb_descriptor_header *otg_desc);
 918/*-------------------------------------------------------------------------*/
 919
 920/* utility to simplify map/unmap of usb_requests to/from DMA */
 921
 922#ifdef	CONFIG_HAS_DMA
 923extern int usb_gadget_map_request_by_dev(struct device *dev,
 924		struct usb_request *req, int is_in);
 925extern int usb_gadget_map_request(struct usb_gadget *gadget,
 926		struct usb_request *req, int is_in);
 927
 928extern void usb_gadget_unmap_request_by_dev(struct device *dev,
 929		struct usb_request *req, int is_in);
 930extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
 931		struct usb_request *req, int is_in);
 932#else /* !CONFIG_HAS_DMA */
 933static inline int usb_gadget_map_request_by_dev(struct device *dev,
 934		struct usb_request *req, int is_in) { return -ENOSYS; }
 935static inline int usb_gadget_map_request(struct usb_gadget *gadget,
 936		struct usb_request *req, int is_in) { return -ENOSYS; }
 937
 938static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
 939		struct usb_request *req, int is_in) { }
 940static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
 941		struct usb_request *req, int is_in) { }
 942#endif /* !CONFIG_HAS_DMA */
 943
 944/*-------------------------------------------------------------------------*/
 945
 946/* utility to set gadget state properly */
 947
 948extern void usb_gadget_set_state(struct usb_gadget *gadget,
 949		enum usb_device_state state);
 950
 951/*-------------------------------------------------------------------------*/
 952
 953/* utility to tell udc core that the bus reset occurs */
 954extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
 955		struct usb_gadget_driver *driver);
 956
 957/*-------------------------------------------------------------------------*/
 958
 959/* utility to give requests back to the gadget layer */
 960
 961extern void usb_gadget_giveback_request(struct usb_ep *ep,
 962		struct usb_request *req);
 963
 964/*-------------------------------------------------------------------------*/
 965
 966/* utility to find endpoint by name */
 967
 968extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
 969		const char *name);
 970
 971/*-------------------------------------------------------------------------*/
 972
 973/* utility to check if endpoint caps match descriptor needs */
 974
 975extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
 976		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
 977		struct usb_ss_ep_comp_descriptor *ep_comp);
 978
 979/*-------------------------------------------------------------------------*/
 980
 981/* utility to update vbus status for udc core, it may be scheduled */
 982extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
 983
 984/*-------------------------------------------------------------------------*/
 985
 986/* utility wrapping a simple endpoint selection policy */
 987
 988extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
 989			struct usb_endpoint_descriptor *);
 990
 991
 992extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
 993			struct usb_endpoint_descriptor *,
 994			struct usb_ss_ep_comp_descriptor *);
 995
 996extern void usb_ep_autoconfig_release(struct usb_ep *);
 997
 998extern void usb_ep_autoconfig_reset(struct usb_gadget *);
 999
1000#endif /* __LINUX_USB_GADGET_H */