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
31struct 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
99struct 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 */
135struct 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 */
165struct 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
225struct 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)
247void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
248int usb_ep_enable(struct usb_ep *ep);
249int usb_ep_disable(struct usb_ep *ep);
250struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
251void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
252int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
253int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
254int usb_ep_set_halt(struct usb_ep *ep);
255int usb_ep_clear_halt(struct usb_ep *ep);
256int usb_ep_set_wedge(struct usb_ep *ep);
257int usb_ep_fifo_status(struct usb_ep *ep);
258void usb_ep_fifo_flush(struct usb_ep *ep);
259#else
260static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
261 unsigned maxpacket_limit)
262{ }
263static inline int usb_ep_enable(struct usb_ep *ep)
264{ return 0; }
265static inline int usb_ep_disable(struct usb_ep *ep)
266{ return 0; }
267static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
268 gfp_t gfp_flags)
269{ return NULL; }
270static inline void usb_ep_free_request(struct usb_ep *ep,
271 struct usb_request *req)
272{ }
273static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
274 gfp_t gfp_flags)
275{ return 0; }
276static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
277{ return 0; }
278static inline int usb_ep_set_halt(struct usb_ep *ep)
279{ return 0; }
280static inline int usb_ep_clear_halt(struct usb_ep *ep)
281{ return 0; }
282static inline int usb_ep_set_wedge(struct usb_ep *ep)
283{ return 0; }
284static inline int usb_ep_fifo_status(struct usb_ep *ep)
285{ return 0; }
286static inline void usb_ep_fifo_flush(struct usb_ep *ep)
287{ }
288#endif /* USB_GADGET */
289
290/*-------------------------------------------------------------------------*/
291
292struct 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
303struct usb_gadget;
304struct usb_gadget_driver;
305struct 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 */
310struct usb_gadget_ops {
311 int (*get_frame)(struct usb_gadget *);
312 int (*wakeup)(struct usb_gadget *);
313 int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
314 int (*set_remote_wakeup)(struct usb_gadget *, int set);
315 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
316 int (*vbus_session) (struct usb_gadget *, int is_active);
317 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
318 int (*pullup) (struct usb_gadget *, int is_on);
319 int (*ioctl)(struct usb_gadget *,
320 unsigned code, unsigned long param);
321 void (*get_config_params)(struct usb_gadget *,
322 struct usb_dcd_config_params *);
323 int (*udc_start)(struct usb_gadget *,
324 struct usb_gadget_driver *);
325 int (*udc_stop)(struct usb_gadget *);
326 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
327 void (*udc_set_ssp_rate)(struct usb_gadget *gadget,
328 enum usb_ssp_rate rate);
329 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
330 struct usb_ep *(*match_ep)(struct usb_gadget *,
331 struct usb_endpoint_descriptor *,
332 struct usb_ss_ep_comp_descriptor *);
333 int (*check_config)(struct usb_gadget *gadget);
334};
335
336/**
337 * struct usb_gadget - represents a usb device
338 * @work: (internal use) Workqueue to be used for sysfs_notify()
339 * @udc: struct usb_udc pointer for this gadget
340 * @ops: Function pointers used to access hardware-specific operations.
341 * @ep0: Endpoint zero, used when reading or writing responses to
342 * driver setup() requests
343 * @ep_list: List of other endpoints supported by the device.
344 * @speed: Speed of current connection to USB host.
345 * @max_speed: Maximal speed the UDC can handle. UDC must support this
346 * and all slower speeds.
347 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
348 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
349 * can handle. The UDC must support this and all slower speeds and lower
350 * number of lanes.
351 * @state: the state we are now (attached, suspended, configured, etc)
352 * @name: Identifies the controller hardware type. Used in diagnostics
353 * and sometimes configuration.
354 * @dev: Driver model state for this abstract device.
355 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
356 * @out_epnum: last used out ep number
357 * @in_epnum: last used in ep number
358 * @mA: last set mA value
359 * @otg_caps: OTG capabilities of this gadget.
360 * @sg_supported: true if we can handle scatter-gather
361 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
362 * gadget driver must provide a USB OTG descriptor.
363 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
364 * is in the Mini-AB jack, and HNP has been used to switch roles
365 * so that the "A" device currently acts as A-Peripheral, not A-Host.
366 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
367 * supports HNP at this port.
368 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
369 * only supports HNP on a different root port.
370 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
371 * enabled HNP support.
372 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
373 * in peripheral mode can support HNP polling.
374 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
375 * or B-Peripheral wants to take host role.
376 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
377 * MaxPacketSize.
378 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
379 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
380 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
381 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
382 * u_ether.c to improve performance.
383 * @is_selfpowered: if the gadget is self-powered.
384 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
385 * be connected.
386 * @connected: True if gadget is connected.
387 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
388 * indicates that it supports LPM as per the LPM ECN & errata.
389 * @wakeup_capable: True if gadget is capable of sending remote wakeup.
390 * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
391 * @irq: the interrupt number for device controller.
392 * @id_number: a unique ID number for ensuring that gadget names are distinct
393 *
394 * Gadgets have a mostly-portable "gadget driver" implementing device
395 * functions, handling all usb configurations and interfaces. Gadget
396 * drivers talk to hardware-specific code indirectly, through ops vectors.
397 * That insulates the gadget driver from hardware details, and packages
398 * the hardware endpoints through generic i/o queues. The "usb_gadget"
399 * and "usb_ep" interfaces provide that insulation from the hardware.
400 *
401 * Except for the driver data, all fields in this structure are
402 * read-only to the gadget driver. That driver data is part of the
403 * "driver model" infrastructure in 2.6 (and later) kernels, and for
404 * earlier systems is grouped in a similar structure that's not known
405 * to the rest of the kernel.
406 *
407 * Values of the three OTG device feature flags are updated before the
408 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
409 * driver suspend() calls. They are valid only when is_otg, and when the
410 * device is acting as a B-Peripheral (so is_a_peripheral is false).
411 */
412struct usb_gadget {
413 struct work_struct work;
414 struct usb_udc *udc;
415 /* readonly to gadget driver */
416 const struct usb_gadget_ops *ops;
417 struct usb_ep *ep0;
418 struct list_head ep_list; /* of usb_ep */
419 enum usb_device_speed speed;
420 enum usb_device_speed max_speed;
421
422 /* USB SuperSpeed Plus only */
423 enum usb_ssp_rate ssp_rate;
424 enum usb_ssp_rate max_ssp_rate;
425
426 enum usb_device_state state;
427 const char *name;
428 struct device dev;
429 unsigned isoch_delay;
430 unsigned out_epnum;
431 unsigned in_epnum;
432 unsigned mA;
433 struct usb_otg_caps *otg_caps;
434
435 unsigned sg_supported:1;
436 unsigned is_otg:1;
437 unsigned is_a_peripheral:1;
438 unsigned b_hnp_enable:1;
439 unsigned a_hnp_support:1;
440 unsigned a_alt_hnp_support:1;
441 unsigned hnp_polling_support:1;
442 unsigned host_request_flag:1;
443 unsigned quirk_ep_out_aligned_size:1;
444 unsigned quirk_altset_not_supp:1;
445 unsigned quirk_stall_not_supp:1;
446 unsigned quirk_zlp_not_supp:1;
447 unsigned quirk_avoids_skb_reserve:1;
448 unsigned is_selfpowered:1;
449 unsigned deactivated:1;
450 unsigned connected:1;
451 unsigned lpm_capable:1;
452 unsigned wakeup_capable:1;
453 unsigned wakeup_armed:1;
454 int irq;
455 int id_number;
456};
457#define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
458
459/* Interface to the device model */
460static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
461 { dev_set_drvdata(dev: &gadget->dev, data); }
462static inline void *get_gadget_data(struct usb_gadget *gadget)
463 { return dev_get_drvdata(dev: &gadget->dev); }
464static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
465{
466 return container_of(dev, struct usb_gadget, dev);
467}
468static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
469{
470 get_device(dev: &gadget->dev);
471 return gadget;
472}
473static inline void usb_put_gadget(struct usb_gadget *gadget)
474{
475 put_device(dev: &gadget->dev);
476}
477extern void usb_initialize_gadget(struct device *parent,
478 struct usb_gadget *gadget, void (*release)(struct device *dev));
479extern int usb_add_gadget(struct usb_gadget *gadget);
480extern void usb_del_gadget(struct usb_gadget *gadget);
481
482/* Legacy device-model interface */
483extern int usb_add_gadget_udc_release(struct device *parent,
484 struct usb_gadget *gadget, void (*release)(struct device *dev));
485extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
486extern void usb_del_gadget_udc(struct usb_gadget *gadget);
487extern char *usb_get_gadget_udc_name(void);
488
489/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
490#define gadget_for_each_ep(tmp, gadget) \
491 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
492
493/**
494 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
495 * @ep: the endpoint whose maxpacketsize is used to align @len
496 * @len: buffer size's length to align to @ep's maxpacketsize
497 *
498 * This helper is used to align buffer's size to an ep's maxpacketsize.
499 */
500static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
501{
502 int max_packet_size = (size_t)usb_endpoint_maxp(epd: ep->desc);
503
504 return round_up(len, max_packet_size);
505}
506
507/**
508 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
509 * requires quirk_ep_out_aligned_size, otherwise returns len.
510 * @g: controller to check for quirk
511 * @ep: the endpoint whose maxpacketsize is used to align @len
512 * @len: buffer size's length to align to @ep's maxpacketsize
513 *
514 * This helper is used in case it's required for any reason to check and maybe
515 * align buffer's size to an ep's maxpacketsize.
516 */
517static inline size_t
518usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
519{
520 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
521}
522
523/**
524 * gadget_is_altset_supported - return true iff the hardware supports
525 * altsettings
526 * @g: controller to check for quirk
527 */
528static inline int gadget_is_altset_supported(struct usb_gadget *g)
529{
530 return !g->quirk_altset_not_supp;
531}
532
533/**
534 * gadget_is_stall_supported - return true iff the hardware supports stalling
535 * @g: controller to check for quirk
536 */
537static inline int gadget_is_stall_supported(struct usb_gadget *g)
538{
539 return !g->quirk_stall_not_supp;
540}
541
542/**
543 * gadget_is_zlp_supported - return true iff the hardware supports zlp
544 * @g: controller to check for quirk
545 */
546static inline int gadget_is_zlp_supported(struct usb_gadget *g)
547{
548 return !g->quirk_zlp_not_supp;
549}
550
551/**
552 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
553 * skb_reserve to improve performance.
554 * @g: controller to check for quirk
555 */
556static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
557{
558 return g->quirk_avoids_skb_reserve;
559}
560
561/**
562 * gadget_is_dualspeed - return true iff the hardware handles high speed
563 * @g: controller that might support both high and full speeds
564 */
565static inline int gadget_is_dualspeed(struct usb_gadget *g)
566{
567 return g->max_speed >= USB_SPEED_HIGH;
568}
569
570/**
571 * gadget_is_superspeed() - return true if the hardware handles superspeed
572 * @g: controller that might support superspeed
573 */
574static inline int gadget_is_superspeed(struct usb_gadget *g)
575{
576 return g->max_speed >= USB_SPEED_SUPER;
577}
578
579/**
580 * gadget_is_superspeed_plus() - return true if the hardware handles
581 * superspeed plus
582 * @g: controller that might support superspeed plus
583 */
584static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
585{
586 return g->max_speed >= USB_SPEED_SUPER_PLUS;
587}
588
589/**
590 * gadget_is_otg - return true iff the hardware is OTG-ready
591 * @g: controller that might have a Mini-AB connector
592 *
593 * This is a runtime test, since kernels with a USB-OTG stack sometimes
594 * run on boards which only have a Mini-B (or Mini-A) connector.
595 */
596static inline int gadget_is_otg(struct usb_gadget *g)
597{
598#ifdef CONFIG_USB_OTG
599 return g->is_otg;
600#else
601 return 0;
602#endif
603}
604
605/*-------------------------------------------------------------------------*/
606
607#if IS_ENABLED(CONFIG_USB_GADGET)
608int usb_gadget_frame_number(struct usb_gadget *gadget);
609int usb_gadget_wakeup(struct usb_gadget *gadget);
610int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
611int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
612int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
613int usb_gadget_vbus_connect(struct usb_gadget *gadget);
614int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
615int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
616int usb_gadget_connect(struct usb_gadget *gadget);
617int usb_gadget_disconnect(struct usb_gadget *gadget);
618int usb_gadget_deactivate(struct usb_gadget *gadget);
619int usb_gadget_activate(struct usb_gadget *gadget);
620int usb_gadget_check_config(struct usb_gadget *gadget);
621#else
622static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
623{ return 0; }
624static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
625{ return 0; }
626static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
627{ return 0; }
628static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
629{ return 0; }
630static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
631{ return 0; }
632static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
633{ return 0; }
634static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
635{ return 0; }
636static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
637{ return 0; }
638static inline int usb_gadget_connect(struct usb_gadget *gadget)
639{ return 0; }
640static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
641{ return 0; }
642static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
643{ return 0; }
644static inline int usb_gadget_activate(struct usb_gadget *gadget)
645{ return 0; }
646static inline int usb_gadget_check_config(struct usb_gadget *gadget)
647{ return 0; }
648#endif /* CONFIG_USB_GADGET */
649
650/*-------------------------------------------------------------------------*/
651
652/**
653 * struct usb_gadget_driver - driver for usb gadget devices
654 * @function: String describing the gadget's function
655 * @max_speed: Highest speed the driver handles.
656 * @setup: Invoked for ep0 control requests that aren't handled by
657 * the hardware level driver. Most calls must be handled by
658 * the gadget driver, including descriptor and configuration
659 * management. The 16 bit members of the setup data are in
660 * USB byte order. Called in_interrupt; this may not sleep. Driver
661 * queues a response to ep0, or returns negative to stall.
662 * @disconnect: Invoked after all transfers have been stopped,
663 * when the host is disconnected. May be called in_interrupt; this
664 * may not sleep. Some devices can't detect disconnect, so this might
665 * not be called except as part of controller shutdown.
666 * @bind: the driver's bind callback
667 * @unbind: Invoked when the driver is unbound from a gadget,
668 * usually from rmmod (after a disconnect is reported).
669 * Called in a context that permits sleeping.
670 * @suspend: Invoked on USB suspend. May be called in_interrupt.
671 * @resume: Invoked on USB resume. May be called in_interrupt.
672 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
673 * and should be called in_interrupt.
674 * @driver: Driver model state for this driver.
675 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
676 * this driver will be bound to any available UDC.
677 * @match_existing_only: If udc is not found, return an error and fail
678 * the driver registration
679 * @is_bound: Allow a driver to be bound to only one gadget
680 *
681 * Devices are disabled till a gadget driver successfully bind()s, which
682 * means the driver will handle setup() requests needed to enumerate (and
683 * meet "chapter 9" requirements) then do some useful work.
684 *
685 * If gadget->is_otg is true, the gadget driver must provide an OTG
686 * descriptor during enumeration, or else fail the bind() call. In such
687 * cases, no USB traffic may flow until both bind() returns without
688 * having called usb_gadget_disconnect(), and the USB host stack has
689 * initialized.
690 *
691 * Drivers use hardware-specific knowledge to configure the usb hardware.
692 * endpoint addressing is only one of several hardware characteristics that
693 * are in descriptors the ep0 implementation returns from setup() calls.
694 *
695 * Except for ep0 implementation, most driver code shouldn't need change to
696 * run on top of different usb controllers. It'll use endpoints set up by
697 * that ep0 implementation.
698 *
699 * The usb controller driver handles a few standard usb requests. Those
700 * include set_address, and feature flags for devices, interfaces, and
701 * endpoints (the get_status, set_feature, and clear_feature requests).
702 *
703 * Accordingly, the driver's setup() callback must always implement all
704 * get_descriptor requests, returning at least a device descriptor and
705 * a configuration descriptor. Drivers must make sure the endpoint
706 * descriptors match any hardware constraints. Some hardware also constrains
707 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
708 *
709 * The driver's setup() callback must also implement set_configuration,
710 * and should also implement set_interface, get_configuration, and
711 * get_interface. Setting a configuration (or interface) is where
712 * endpoints should be activated or (config 0) shut down.
713 *
714 * The gadget driver's setup() callback does not have to queue a response to
715 * ep0 within the setup() call, the driver can do it after setup() returns.
716 * The UDC driver must wait until such a response is queued before proceeding
717 * with the data/status stages of the control transfer.
718 *
719 * NOTE: Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS
720 * being returned from the setup() callback, which is a bug. See the comment
721 * next to USB_GADGET_DELAYED_STATUS for details.
722 *
723 * (Note that only the default control endpoint is supported. Neither
724 * hosts nor devices generally support control traffic except to ep0.)
725 *
726 * Most devices will ignore USB suspend/resume operations, and so will
727 * not provide those callbacks. However, some may need to change modes
728 * when the host is not longer directing those activities. For example,
729 * local controls (buttons, dials, etc) may need to be re-enabled since
730 * the (remote) host can't do that any longer; or an error state might
731 * be cleared, to make the device behave identically whether or not
732 * power is maintained.
733 */
734struct usb_gadget_driver {
735 char *function;
736 enum usb_device_speed max_speed;
737 int (*bind)(struct usb_gadget *gadget,
738 struct usb_gadget_driver *driver);
739 void (*unbind)(struct usb_gadget *);
740 int (*setup)(struct usb_gadget *,
741 const struct usb_ctrlrequest *);
742 void (*disconnect)(struct usb_gadget *);
743 void (*suspend)(struct usb_gadget *);
744 void (*resume)(struct usb_gadget *);
745 void (*reset)(struct usb_gadget *);
746
747 /* FIXME support safe rmmod */
748 struct device_driver driver;
749
750 char *udc_name;
751 unsigned match_existing_only:1;
752 bool is_bound:1;
753};
754
755
756
757/*-------------------------------------------------------------------------*/
758
759/* driver modules register and unregister, as usual.
760 * these calls must be made in a context that can sleep.
761 *
762 * A gadget driver can be bound to only one gadget at a time.
763 */
764
765/**
766 * usb_gadget_register_driver_owner - register a gadget driver
767 * @driver: the driver being registered
768 * @owner: the driver module
769 * @mod_name: the driver module's build name
770 * Context: can sleep
771 *
772 * Call this in your gadget driver's module initialization function,
773 * to tell the underlying UDC controller driver about your driver.
774 * The @bind() function will be called to bind it to a gadget before this
775 * registration call returns. It's expected that the @bind() function will
776 * be in init sections.
777 *
778 * Use the macro defined below instead of calling this directly.
779 */
780int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
781 struct module *owner, const char *mod_name);
782
783/* use a define to avoid include chaining to get THIS_MODULE & friends */
784#define usb_gadget_register_driver(driver) \
785 usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME)
786
787/**
788 * usb_gadget_unregister_driver - unregister a gadget driver
789 * @driver:the driver being unregistered
790 * Context: can sleep
791 *
792 * Call this in your gadget driver's module cleanup function,
793 * to tell the underlying usb controller that your driver is
794 * going away. If the controller is connected to a USB host,
795 * it will first disconnect(). The driver is also requested
796 * to unbind() and clean up any device state, before this procedure
797 * finally returns. It's expected that the unbind() functions
798 * will be in exit sections, so may not be linked in some kernels.
799 */
800int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
801
802/*-------------------------------------------------------------------------*/
803
804/* utility to simplify dealing with string descriptors */
805
806/**
807 * struct usb_string - wraps a C string and its USB id
808 * @id:the (nonzero) ID for this string
809 * @s:the string, in UTF-8 encoding
810 *
811 * If you're using usb_gadget_get_string(), use this to wrap a string
812 * together with its ID.
813 */
814struct usb_string {
815 u8 id;
816 const char *s;
817};
818
819/**
820 * struct usb_gadget_strings - a set of USB strings in a given language
821 * @language:identifies the strings' language (0x0409 for en-us)
822 * @strings:array of strings with their ids
823 *
824 * If you're using usb_gadget_get_string(), use this to wrap all the
825 * strings for a given language.
826 */
827struct usb_gadget_strings {
828 u16 language; /* 0x0409 for en-us */
829 struct usb_string *strings;
830};
831
832struct usb_gadget_string_container {
833 struct list_head list;
834 u8 *stash[];
835};
836
837/* put descriptor for string with that id into buf (buflen >= 256) */
838int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
839
840/* check if the given language identifier is valid */
841bool usb_validate_langid(u16 langid);
842
843struct gadget_string {
844 struct config_item item;
845 struct list_head list;
846 char string[USB_MAX_STRING_LEN];
847 struct usb_string usb_string;
848};
849
850#define to_gadget_string(str_item)\
851container_of(str_item, struct gadget_string, item)
852
853/*-------------------------------------------------------------------------*/
854
855/* utility to simplify managing config descriptors */
856
857/* write vector of descriptors into buffer */
858int usb_descriptor_fillbuf(void *, unsigned,
859 const struct usb_descriptor_header **);
860
861/* build config descriptor from single descriptor vector */
862int usb_gadget_config_buf(const struct usb_config_descriptor *config,
863 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
864
865/* copy a NULL-terminated vector of descriptors */
866struct usb_descriptor_header **usb_copy_descriptors(
867 struct usb_descriptor_header **);
868
869/**
870 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
871 * @v: vector of descriptors
872 */
873static inline void usb_free_descriptors(struct usb_descriptor_header **v)
874{
875 kfree(objp: v);
876}
877
878struct usb_function;
879int usb_assign_descriptors(struct usb_function *f,
880 struct usb_descriptor_header **fs,
881 struct usb_descriptor_header **hs,
882 struct usb_descriptor_header **ss,
883 struct usb_descriptor_header **ssp);
884void usb_free_all_descriptors(struct usb_function *f);
885
886struct usb_descriptor_header *usb_otg_descriptor_alloc(
887 struct usb_gadget *gadget);
888int usb_otg_descriptor_init(struct usb_gadget *gadget,
889 struct usb_descriptor_header *otg_desc);
890/*-------------------------------------------------------------------------*/
891
892/* utility to simplify map/unmap of usb_requests to/from DMA */
893
894#ifdef CONFIG_HAS_DMA
895extern int usb_gadget_map_request_by_dev(struct device *dev,
896 struct usb_request *req, int is_in);
897extern int usb_gadget_map_request(struct usb_gadget *gadget,
898 struct usb_request *req, int is_in);
899
900extern void usb_gadget_unmap_request_by_dev(struct device *dev,
901 struct usb_request *req, int is_in);
902extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
903 struct usb_request *req, int is_in);
904#else /* !CONFIG_HAS_DMA */
905static inline int usb_gadget_map_request_by_dev(struct device *dev,
906 struct usb_request *req, int is_in) { return -ENOSYS; }
907static inline int usb_gadget_map_request(struct usb_gadget *gadget,
908 struct usb_request *req, int is_in) { return -ENOSYS; }
909
910static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
911 struct usb_request *req, int is_in) { }
912static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
913 struct usb_request *req, int is_in) { }
914#endif /* !CONFIG_HAS_DMA */
915
916/*-------------------------------------------------------------------------*/
917
918/* utility to set gadget state properly */
919
920extern void usb_gadget_set_state(struct usb_gadget *gadget,
921 enum usb_device_state state);
922
923/*-------------------------------------------------------------------------*/
924
925/* utility to tell udc core that the bus reset occurs */
926extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
927 struct usb_gadget_driver *driver);
928
929/*-------------------------------------------------------------------------*/
930
931/* utility to give requests back to the gadget layer */
932
933extern void usb_gadget_giveback_request(struct usb_ep *ep,
934 struct usb_request *req);
935
936/*-------------------------------------------------------------------------*/
937
938/* utility to find endpoint by name */
939
940extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
941 const char *name);
942
943/*-------------------------------------------------------------------------*/
944
945/* utility to check if endpoint caps match descriptor needs */
946
947extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
948 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
949 struct usb_ss_ep_comp_descriptor *ep_comp);
950
951/*-------------------------------------------------------------------------*/
952
953/* utility to update vbus status for udc core, it may be scheduled */
954extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
955
956/*-------------------------------------------------------------------------*/
957
958/* utility wrapping a simple endpoint selection policy */
959
960extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
961 struct usb_endpoint_descriptor *);
962
963
964extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
965 struct usb_endpoint_descriptor *,
966 struct usb_ss_ep_comp_descriptor *);
967
968extern void usb_ep_autoconfig_release(struct usb_ep *);
969
970extern void usb_ep_autoconfig_reset(struct usb_gadget *);
971
972#endif /* __LINUX_USB_GADGET_H */
973

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