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(objp: req->buf);
312 usb_ep_free_request(ep: 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(dev: &gadget->dev, data); }
494static inline void *get_gadget_data(struct usb_gadget *gadget)
495 { return dev_get_drvdata(dev: &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(dev: &gadget->dev);
503 return gadget;
504}
505static inline void usb_put_gadget(struct usb_gadget *gadget)
506{
507 put_device(dev: &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(epd: 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(objp: 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 */
1001

source code of linux/include/linux/usb/gadget.h