1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * <linux/usb/gadget.h>
4 *
5 * We call the USB code inside a Linux-based peripheral device a "gadget"
6 * driver, except for the hardware-specific bus glue. One USB host can
7 * talk to many USB gadgets, but the gadgets are only able to communicate
8 * to one host.
9 *
10 *
11 * (C) Copyright 2002-2004 by David Brownell
12 * All Rights Reserved.
13 */
14
15 #ifndef __LINUX_USB_GADGET_H
16 #define __LINUX_USB_GADGET_H
17
18 #include <linux/configfs.h>
19 #include <linux/device.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/scatterlist.h>
25 #include <linux/types.h>
26 #include <linux/workqueue.h>
27 #include <linux/usb/ch9.h>
28
29 #define UDC_TRACE_STR_MAX 512
30
31 struct usb_ep;
32
33 /**
34 * struct usb_request - describes one i/o request
35 * @buf: Buffer used for data. Always provide this; some controllers
36 * only use PIO, or don't use DMA for some endpoints.
37 * @dma: DMA address corresponding to 'buf'. If you don't set this
38 * field, and the usb controller needs one, it is responsible
39 * for mapping and unmapping the buffer.
40 * @sg: a scatterlist for SG-capable controllers.
41 * @num_sgs: number of SG entries
42 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
43 * @length: Length of that data
44 * @stream_id: The stream id, when USB3.0 bulk streams are being used
45 * @is_last: Indicates if this is the last request of a stream_id before
46 * switching to a different stream (required for DWC3 controllers).
47 * @no_interrupt: If true, hints that no completion irq is needed.
48 * Helpful sometimes with deep request queues that are handled
49 * directly by DMA controllers.
50 * @zero: If true, when writing data, makes the last packet be "short"
51 * by adding a zero length packet as needed;
52 * @short_not_ok: When reading data, makes short packets be
53 * treated as errors (queue stops advancing till cleanup).
54 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
55 * @sg_was_mapped: Set if the scatterlist has been mapped before the request
56 * @complete: Function called when request completes, so this request and
57 * its buffer may be re-used. The function will always be called with
58 * interrupts disabled, and it must not sleep.
59 * Reads terminate with a short packet, or when the buffer fills,
60 * whichever comes first. When writes terminate, some data bytes
61 * will usually still be in flight (often in a hardware fifo).
62 * Errors (for reads or writes) stop the queue from advancing
63 * until the completion function returns, so that any transfers
64 * invalidated by the error may first be dequeued.
65 * @context: For use by the completion callback
66 * @list: For use by the gadget driver.
67 * @frame_number: Reports the interval number in (micro)frame in which the
68 * isochronous transfer was transmitted or received.
69 * @status: Reports completion code, zero or a negative errno.
70 * Normally, faults block the transfer queue from advancing until
71 * the completion callback returns.
72 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
73 * or when the driver disabled the endpoint.
74 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
75 * transfers) this may be less than the requested length. If the
76 * short_not_ok flag is set, short reads are treated as errors
77 * even when status otherwise indicates successful completion.
78 * Note that for writes (IN transfers) some data bytes may still
79 * reside in a device-side FIFO when the request is reported as
80 * complete.
81 *
82 * These are allocated/freed through the endpoint they're used with. The
83 * hardware's driver can add extra per-request data to the memory it returns,
84 * which often avoids separate memory allocations (potential failures),
85 * later when the request is queued.
86 *
87 * Request flags affect request handling, such as whether a zero length
88 * packet is written (the "zero" flag), whether a short read should be
89 * treated as an error (blocking request queue advance, the "short_not_ok"
90 * flag), or hinting that an interrupt is not required (the "no_interrupt"
91 * flag, for use with deep request queues).
92 *
93 * Bulk endpoints can use any size buffers, and can also be used for interrupt
94 * transfers. interrupt-only endpoints can be much less functional.
95 *
96 * NOTE: this is analogous to 'struct urb' on the host side, except that
97 * it's thinner and promotes more pre-allocation.
98 */
99
100 struct usb_request {
101 void *buf;
102 unsigned length;
103 dma_addr_t dma;
104
105 struct scatterlist *sg;
106 unsigned num_sgs;
107 unsigned num_mapped_sgs;
108
109 unsigned stream_id:16;
110 unsigned is_last:1;
111 unsigned no_interrupt:1;
112 unsigned zero:1;
113 unsigned short_not_ok:1;
114 unsigned dma_mapped:1;
115 unsigned sg_was_mapped:1;
116
117 void (*complete)(struct usb_ep *ep,
118 struct usb_request *req);
119 void *context;
120 struct list_head list;
121
122 unsigned frame_number; /* ISO ONLY */
123
124 int status;
125 unsigned actual;
126 };
127
128 /*-------------------------------------------------------------------------*/
129
130 /* endpoint-specific parts of the api to the usb controller hardware.
131 * unlike the urb model, (de)multiplexing layers are not required.
132 * (so this api could slash overhead if used on the host side...)
133 *
134 * note that device side usb controllers commonly differ in how many
135 * endpoints they support, as well as their capabilities.
136 */
137 struct usb_ep_ops {
138 int (*enable) (struct usb_ep *ep,
139 const struct usb_endpoint_descriptor *desc);
140 int (*disable) (struct usb_ep *ep);
141 void (*dispose) (struct usb_ep *ep);
142
143 struct usb_request *(*alloc_request) (struct usb_ep *ep,
144 gfp_t gfp_flags);
145 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
146
147 int (*queue) (struct usb_ep *ep, struct usb_request *req,
148 gfp_t gfp_flags);
149 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
150
151 int (*set_halt) (struct usb_ep *ep, int value);
152 int (*set_wedge) (struct usb_ep *ep);
153
154 int (*fifo_status) (struct usb_ep *ep);
155 void (*fifo_flush) (struct usb_ep *ep);
156 };
157
158 /**
159 * struct usb_ep_caps - endpoint capabilities description
160 * @type_control:Endpoint supports control type (reserved for ep0).
161 * @type_iso:Endpoint supports isochronous transfers.
162 * @type_bulk:Endpoint supports bulk transfers.
163 * @type_int:Endpoint supports interrupt transfers.
164 * @dir_in:Endpoint supports IN direction.
165 * @dir_out:Endpoint supports OUT direction.
166 */
167 struct usb_ep_caps {
168 unsigned type_control:1;
169 unsigned type_iso:1;
170 unsigned type_bulk:1;
171 unsigned type_int:1;
172 unsigned dir_in:1;
173 unsigned dir_out:1;
174 };
175
176 #define USB_EP_CAPS_TYPE_CONTROL 0x01
177 #define USB_EP_CAPS_TYPE_ISO 0x02
178 #define USB_EP_CAPS_TYPE_BULK 0x04
179 #define USB_EP_CAPS_TYPE_INT 0x08
180 #define USB_EP_CAPS_TYPE_ALL \
181 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
182 #define USB_EP_CAPS_DIR_IN 0x01
183 #define USB_EP_CAPS_DIR_OUT 0x02
184 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
185
186 #define USB_EP_CAPS(_type, _dir) \
187 { \
188 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
189 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
190 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
191 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
192 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
193 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
194 }
195
196 /**
197 * struct usb_ep - device side representation of USB endpoint
198 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
199 * @ops: Function pointers used to access hardware-specific operations.
200 * @ep_list:the gadget's ep_list holds all of its endpoints
201 * @caps:The structure describing types and directions supported by endpoint.
202 * @enabled: The current endpoint enabled/disabled state.
203 * @claimed: True if this endpoint is claimed by a function.
204 * @maxpacket:The maximum packet size used on this endpoint. The initial
205 * value can sometimes be reduced (hardware allowing), according to
206 * the endpoint descriptor used to configure the endpoint.
207 * @maxpacket_limit:The maximum packet size value which can be handled by this
208 * endpoint. It's set once by UDC driver when endpoint is initialized, and
209 * should not be changed. Should not be confused with maxpacket.
210 * @max_streams: The maximum number of streams supported
211 * by this EP (0 - 16, actual number is 2^n)
212 * @mult: multiplier, 'mult' value for SS Isoc EPs
213 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
214 * @driver_data:for use by the gadget driver.
215 * @address: used to identify the endpoint when finding descriptor that
216 * matches connection speed
217 * @desc: endpoint descriptor. This pointer is set before the endpoint is
218 * enabled and remains valid until the endpoint is disabled.
219 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
220 * descriptor that is used to configure the endpoint
221 *
222 * the bus controller driver lists all the general purpose endpoints in
223 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
224 * and is accessed only in response to a driver setup() callback.
225 */
226
227 struct usb_ep {
228 void *driver_data;
229
230 const char *name;
231 const struct usb_ep_ops *ops;
232 const struct usb_endpoint_descriptor *desc;
233 const struct usb_ss_ep_comp_descriptor *comp_desc;
234 struct list_head ep_list;
235 struct usb_ep_caps caps;
236 bool claimed;
237 bool enabled;
238 unsigned mult:2;
239 unsigned maxburst:5;
240 u8 address;
241 u16 maxpacket;
242 u16 maxpacket_limit;
243 u16 max_streams;
244 };
245
246 /*-------------------------------------------------------------------------*/
247
248 #if IS_ENABLED(CONFIG_USB_GADGET)
249 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
250 int usb_ep_enable(struct usb_ep *ep);
251 int usb_ep_disable(struct usb_ep *ep);
252 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
253 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
254 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
255 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
256 int usb_ep_set_halt(struct usb_ep *ep);
257 int usb_ep_clear_halt(struct usb_ep *ep);
258 int usb_ep_set_wedge(struct usb_ep *ep);
259 int usb_ep_fifo_status(struct usb_ep *ep);
260 void usb_ep_fifo_flush(struct usb_ep *ep);
261 #else
262 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
263 unsigned maxpacket_limit)
264 { }
265 static inline int usb_ep_enable(struct usb_ep *ep)
266 { return 0; }
267 static inline int usb_ep_disable(struct usb_ep *ep)
268 { return 0; }
269 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
270 gfp_t gfp_flags)
271 { return NULL; }
272 static inline void usb_ep_free_request(struct usb_ep *ep,
273 struct usb_request *req)
274 { }
275 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
276 gfp_t gfp_flags)
277 { return 0; }
278 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
279 { return 0; }
280 static inline int usb_ep_set_halt(struct usb_ep *ep)
281 { return 0; }
282 static inline int usb_ep_clear_halt(struct usb_ep *ep)
283 { return 0; }
284 static inline int usb_ep_set_wedge(struct usb_ep *ep)
285 { return 0; }
286 static inline int usb_ep_fifo_status(struct usb_ep *ep)
287 { return 0; }
288 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
289 { }
290 #endif /* USB_GADGET */
291
292 /*-------------------------------------------------------------------------*/
293
294 struct usb_dcd_config_params {
295 __u8 bU1devExitLat; /* U1 Device exit Latency */
296 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
297 __le16 bU2DevExitLat; /* U2 Device exit Latency */
298 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
299 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */
300 __u8 besl_deep; /* Recommended deep BESL (0-15) */
301 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
302 };
303
304
305 struct usb_gadget;
306 struct usb_gadget_driver;
307 struct usb_udc;
308
309 /* the rest of the api to the controller hardware: device operations,
310 * which don't involve endpoints (or i/o).
311 */
312 struct usb_gadget_ops {
313 int (*get_frame)(struct usb_gadget *);
314 int (*wakeup)(struct usb_gadget *);
315 int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
316 int (*set_remote_wakeup)(struct usb_gadget *, int set);
317 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
318 int (*vbus_session) (struct usb_gadget *, int is_active);
319 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
320 int (*pullup) (struct usb_gadget *, int is_on);
321 int (*ioctl)(struct usb_gadget *,
322 unsigned code, unsigned long param);
323 void (*get_config_params)(struct usb_gadget *,
324 struct usb_dcd_config_params *);
325 int (*udc_start)(struct usb_gadget *,
326 struct usb_gadget_driver *);
327 int (*udc_stop)(struct usb_gadget *);
328 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
329 void (*udc_set_ssp_rate)(struct usb_gadget *gadget,
330 enum usb_ssp_rate rate);
331 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
332 struct usb_ep *(*match_ep)(struct usb_gadget *,
333 struct usb_endpoint_descriptor *,
334 struct usb_ss_ep_comp_descriptor *);
335 int (*check_config)(struct usb_gadget *gadget);
336 };
337
338 /**
339 * struct usb_gadget - represents a usb device
340 * @work: (internal use) Workqueue to be used for sysfs_notify()
341 * @udc: struct usb_udc pointer for this gadget
342 * @ops: Function pointers used to access hardware-specific operations.
343 * @ep0: Endpoint zero, used when reading or writing responses to
344 * driver setup() requests
345 * @ep_list: List of other endpoints supported by the device.
346 * @speed: Speed of current connection to USB host.
347 * @max_speed: Maximal speed the UDC can handle. UDC must support this
348 * and all slower speeds.
349 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
350 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
351 * can handle. The UDC must support this and all slower speeds and lower
352 * number of lanes.
353 * @state: the state we are now (attached, suspended, configured, etc)
354 * @name: Identifies the controller hardware type. Used in diagnostics
355 * and sometimes configuration.
356 * @dev: Driver model state for this abstract device.
357 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
358 * @out_epnum: last used out ep number
359 * @in_epnum: last used in ep number
360 * @mA: last set mA value
361 * @otg_caps: OTG capabilities of this gadget.
362 * @sg_supported: true if we can handle scatter-gather
363 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
364 * gadget driver must provide a USB OTG descriptor.
365 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
366 * is in the Mini-AB jack, and HNP has been used to switch roles
367 * so that the "A" device currently acts as A-Peripheral, not A-Host.
368 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
369 * supports HNP at this port.
370 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
371 * only supports HNP on a different root port.
372 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
373 * enabled HNP support.
374 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
375 * in peripheral mode can support HNP polling.
376 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
377 * or B-Peripheral wants to take host role.
378 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
379 * MaxPacketSize.
380 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
381 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
382 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
383 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
384 * u_ether.c to improve performance.
385 * @is_selfpowered: if the gadget is self-powered.
386 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
387 * be connected.
388 * @connected: True if gadget is connected.
389 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
390 * indicates that it supports LPM as per the LPM ECN & errata.
391 * @wakeup_capable: True if gadget is capable of sending remote wakeup.
392 * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
393 * @irq: the interrupt number for device controller.
394 * @id_number: a unique ID number for ensuring that gadget names are distinct
395 *
396 * Gadgets have a mostly-portable "gadget driver" implementing device
397 * functions, handling all usb configurations and interfaces. Gadget
398 * drivers talk to hardware-specific code indirectly, through ops vectors.
399 * That insulates the gadget driver from hardware details, and packages
400 * the hardware endpoints through generic i/o queues. The "usb_gadget"
401 * and "usb_ep" interfaces provide that insulation from the hardware.
402 *
403 * Except for the driver data, all fields in this structure are
404 * read-only to the gadget driver. That driver data is part of the
405 * "driver model" infrastructure in 2.6 (and later) kernels, and for
406 * earlier systems is grouped in a similar structure that's not known
407 * to the rest of the kernel.
408 *
409 * Values of the three OTG device feature flags are updated before the
410 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
411 * driver suspend() calls. They are valid only when is_otg, and when the
412 * device is acting as a B-Peripheral (so is_a_peripheral is false).
413 */
414 struct usb_gadget {
415 struct work_struct work;
416 struct usb_udc *udc;
417 /* readonly to gadget driver */
418 const struct usb_gadget_ops *ops;
419 struct usb_ep *ep0;
420 struct list_head ep_list; /* of usb_ep */
421 enum usb_device_speed speed;
422 enum usb_device_speed max_speed;
423
424 /* USB SuperSpeed Plus only */
425 enum usb_ssp_rate ssp_rate;
426 enum usb_ssp_rate max_ssp_rate;
427
428 enum usb_device_state state;
429 const char *name;
430 struct device dev;
431 unsigned isoch_delay;
432 unsigned out_epnum;
433 unsigned in_epnum;
434 unsigned mA;
435 struct usb_otg_caps *otg_caps;
436
437 unsigned sg_supported:1;
438 unsigned is_otg:1;
439 unsigned is_a_peripheral:1;
440 unsigned b_hnp_enable:1;
441 unsigned a_hnp_support:1;
442 unsigned a_alt_hnp_support:1;
443 unsigned hnp_polling_support:1;
444 unsigned host_request_flag:1;
445 unsigned quirk_ep_out_aligned_size:1;
446 unsigned quirk_altset_not_supp:1;
447 unsigned quirk_stall_not_supp:1;
448 unsigned quirk_zlp_not_supp:1;
449 unsigned quirk_avoids_skb_reserve:1;
450 unsigned is_selfpowered:1;
451 unsigned deactivated:1;
452 unsigned connected:1;
453 unsigned lpm_capable:1;
454 unsigned wakeup_capable:1;
455 unsigned wakeup_armed:1;
456 int irq;
457 int id_number;
458 };
459 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
460
461 /* Interface to the device model */
462 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
463 { dev_set_drvdata(&gadget->dev, data); }
464 static inline void *get_gadget_data(struct usb_gadget *gadget)
465 { return dev_get_drvdata(&gadget->dev); }
466 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
467 {
468 return container_of(dev, struct usb_gadget, dev);
469 }
470 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
471 {
472 get_device(&gadget->dev);
473 return gadget;
474 }
475 static inline void usb_put_gadget(struct usb_gadget *gadget)
476 {
477 put_device(&gadget->dev);
478 }
479 extern void usb_initialize_gadget(struct device *parent,
480 struct usb_gadget *gadget, void (*release)(struct device *dev));
481 extern int usb_add_gadget(struct usb_gadget *gadget);
482 extern void usb_del_gadget(struct usb_gadget *gadget);
483
484 /* Legacy device-model interface */
485 extern int usb_add_gadget_udc_release(struct device *parent,
486 struct usb_gadget *gadget, void (*release)(struct device *dev));
487 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
488 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
489 extern char *usb_get_gadget_udc_name(void);
490
491 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
492 #define gadget_for_each_ep(tmp, gadget) \
493 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
494
495 /**
496 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
497 * @ep: the endpoint whose maxpacketsize is used to align @len
498 * @len: buffer size's length to align to @ep's maxpacketsize
499 *
500 * This helper is used to align buffer's size to an ep's maxpacketsize.
501 */
502 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
503 {
504 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc);
505
506 return round_up(len, max_packet_size);
507 }
508
509 /**
510 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
511 * requires quirk_ep_out_aligned_size, otherwise returns len.
512 * @g: controller to check for quirk
513 * @ep: the endpoint whose maxpacketsize is used to align @len
514 * @len: buffer size's length to align to @ep's maxpacketsize
515 *
516 * This helper is used in case it's required for any reason to check and maybe
517 * align buffer's size to an ep's maxpacketsize.
518 */
519 static inline size_t
520 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
521 {
522 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
523 }
524
525 /**
526 * gadget_is_altset_supported - return true iff the hardware supports
527 * altsettings
528 * @g: controller to check for quirk
529 */
530 static inline int gadget_is_altset_supported(struct usb_gadget *g)
531 {
532 return !g->quirk_altset_not_supp;
533 }
534
535 /**
536 * gadget_is_stall_supported - return true iff the hardware supports stalling
537 * @g: controller to check for quirk
538 */
539 static inline int gadget_is_stall_supported(struct usb_gadget *g)
540 {
541 return !g->quirk_stall_not_supp;
542 }
543
544 /**
545 * gadget_is_zlp_supported - return true iff the hardware supports zlp
546 * @g: controller to check for quirk
547 */
548 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
549 {
550 return !g->quirk_zlp_not_supp;
551 }
552
553 /**
554 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
555 * skb_reserve to improve performance.
556 * @g: controller to check for quirk
557 */
558 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
559 {
560 return g->quirk_avoids_skb_reserve;
561 }
562
563 /**
564 * gadget_is_dualspeed - return true iff the hardware handles high speed
565 * @g: controller that might support both high and full speeds
566 */
567 static inline int gadget_is_dualspeed(struct usb_gadget *g)
568 {
569 return g->max_speed >= USB_SPEED_HIGH;
570 }
571
572 /**
573 * gadget_is_superspeed() - return true if the hardware handles superspeed
574 * @g: controller that might support superspeed
575 */
576 static inline int gadget_is_superspeed(struct usb_gadget *g)
577 {
578 return g->max_speed >= USB_SPEED_SUPER;
579 }
580
581 /**
582 * gadget_is_superspeed_plus() - return true if the hardware handles
583 * superspeed plus
584 * @g: controller that might support superspeed plus
585 */
586 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
587 {
588 return g->max_speed >= USB_SPEED_SUPER_PLUS;
589 }
590
591 /**
592 * gadget_is_otg - return true iff the hardware is OTG-ready
593 * @g: controller that might have a Mini-AB connector
594 *
595 * This is a runtime test, since kernels with a USB-OTG stack sometimes
596 * run on boards which only have a Mini-B (or Mini-A) connector.
597 */
598 static inline int gadget_is_otg(struct usb_gadget *g)
599 {
600 #ifdef CONFIG_USB_OTG
601 return g->is_otg;
602 #else
603 return 0;
604 #endif
605 }
606
607 /*-------------------------------------------------------------------------*/
608
609 #if IS_ENABLED(CONFIG_USB_GADGET)
610 int usb_gadget_frame_number(struct usb_gadget *gadget);
611 int usb_gadget_wakeup(struct usb_gadget *gadget);
612 int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
613 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
614 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
615 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
616 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
617 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
618 int usb_gadget_connect(struct usb_gadget *gadget);
619 int usb_gadget_disconnect(struct usb_gadget *gadget);
620 int usb_gadget_deactivate(struct usb_gadget *gadget);
621 int usb_gadget_activate(struct usb_gadget *gadget);
622 int usb_gadget_check_config(struct usb_gadget *gadget);
623 #else
624 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
625 { return 0; }
626 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
627 { return 0; }
628 static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
629 { return 0; }
630 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
631 { return 0; }
632 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
633 { return 0; }
634 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
635 { return 0; }
636 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
637 { return 0; }
638 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
639 { return 0; }
640 static inline int usb_gadget_connect(struct usb_gadget *gadget)
641 { return 0; }
642 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
643 { return 0; }
644 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
645 { return 0; }
646 static inline int usb_gadget_activate(struct usb_gadget *gadget)
647 { return 0; }
648 static inline int usb_gadget_check_config(struct usb_gadget *gadget)
649 { return 0; }
650 #endif /* CONFIG_USB_GADGET */
651
652 /*-------------------------------------------------------------------------*/
653
654 /**
655 * struct usb_gadget_driver - driver for usb gadget devices
656 * @function: String describing the gadget's function
657 * @max_speed: Highest speed the driver handles.
658 * @setup: Invoked for ep0 control requests that aren't handled by
659 * the hardware level driver. Most calls must be handled by
660 * the gadget driver, including descriptor and configuration
661 * management. The 16 bit members of the setup data are in
662 * USB byte order. Called in_interrupt; this may not sleep. Driver
663 * queues a response to ep0, or returns negative to stall.
664 * @disconnect: Invoked after all transfers have been stopped,
665 * when the host is disconnected. May be called in_interrupt; this
666 * may not sleep. Some devices can't detect disconnect, so this might
667 * not be called except as part of controller shutdown.
668 * @bind: the driver's bind callback
669 * @unbind: Invoked when the driver is unbound from a gadget,
670 * usually from rmmod (after a disconnect is reported).
671 * Called in a context that permits sleeping.
672 * @suspend: Invoked on USB suspend. May be called in_interrupt.
673 * @resume: Invoked on USB resume. May be called in_interrupt.
674 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
675 * and should be called in_interrupt.
676 * @driver: Driver model state for this driver.
677 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
678 * this driver will be bound to any available UDC.
679 * @match_existing_only: If udc is not found, return an error and fail
680 * the driver registration
681 * @is_bound: Allow a driver to be bound to only one gadget
682 *
683 * Devices are disabled till a gadget driver successfully bind()s, which
684 * means the driver will handle setup() requests needed to enumerate (and
685 * meet "chapter 9" requirements) then do some useful work.
686 *
687 * If gadget->is_otg is true, the gadget driver must provide an OTG
688 * descriptor during enumeration, or else fail the bind() call. In such
689 * cases, no USB traffic may flow until both bind() returns without
690 * having called usb_gadget_disconnect(), and the USB host stack has
691 * initialized.
692 *
693 * Drivers use hardware-specific knowledge to configure the usb hardware.
694 * endpoint addressing is only one of several hardware characteristics that
695 * are in descriptors the ep0 implementation returns from setup() calls.
696 *
697 * Except for ep0 implementation, most driver code shouldn't need change to
698 * run on top of different usb controllers. It'll use endpoints set up by
699 * that ep0 implementation.
700 *
701 * The usb controller driver handles a few standard usb requests. Those
702 * include set_address, and feature flags for devices, interfaces, and
703 * endpoints (the get_status, set_feature, and clear_feature requests).
704 *
705 * Accordingly, the driver's setup() callback must always implement all
706 * get_descriptor requests, returning at least a device descriptor and
707 * a configuration descriptor. Drivers must make sure the endpoint
708 * descriptors match any hardware constraints. Some hardware also constrains
709 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
710 *
711 * The driver's setup() callback must also implement set_configuration,
712 * and should also implement set_interface, get_configuration, and
713 * get_interface. Setting a configuration (or interface) is where
714 * endpoints should be activated or (config 0) shut down.
715 *
716 * The gadget driver's setup() callback does not have to queue a response to
717 * ep0 within the setup() call, the driver can do it after setup() returns.
718 * The UDC driver must wait until such a response is queued before proceeding
719 * with the data/status stages of the control transfer.
720 *
721 * NOTE: Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS
722 * being returned from the setup() callback, which is a bug. See the comment
723 * next to USB_GADGET_DELAYED_STATUS for details.
724 *
725 * (Note that only the default control endpoint is supported. Neither
726 * hosts nor devices generally support control traffic except to ep0.)
727 *
728 * Most devices will ignore USB suspend/resume operations, and so will
729 * not provide those callbacks. However, some may need to change modes
730 * when the host is not longer directing those activities. For example,
731 * local controls (buttons, dials, etc) may need to be re-enabled since
732 * the (remote) host can't do that any longer; or an error state might
733 * be cleared, to make the device behave identically whether or not
734 * power is maintained.
735 */
736 struct usb_gadget_driver {
737 char *function;
738 enum usb_device_speed max_speed;
739 int (*bind)(struct usb_gadget *gadget,
740 struct usb_gadget_driver *driver);
741 void (*unbind)(struct usb_gadget *);
742 int (*setup)(struct usb_gadget *,
743 const struct usb_ctrlrequest *);
744 void (*disconnect)(struct usb_gadget *);
745 void (*suspend)(struct usb_gadget *);
746 void (*resume)(struct usb_gadget *);
747 void (*reset)(struct usb_gadget *);
748
749 /* FIXME support safe rmmod */
750 struct device_driver driver;
751
752 char *udc_name;
753 unsigned match_existing_only:1;
754 bool is_bound:1;
755 };
756
757
758
759 /*-------------------------------------------------------------------------*/
760
761 /* driver modules register and unregister, as usual.
762 * these calls must be made in a context that can sleep.
763 *
764 * A gadget driver can be bound to only one gadget at a time.
765 */
766
767 /**
768 * usb_gadget_register_driver_owner - register a gadget driver
769 * @driver: the driver being registered
770 * @owner: the driver module
771 * @mod_name: the driver module's build name
772 * Context: can sleep
773 *
774 * Call this in your gadget driver's module initialization function,
775 * to tell the underlying UDC controller driver about your driver.
776 * The @bind() function will be called to bind it to a gadget before this
777 * registration call returns. It's expected that the @bind() function will
778 * be in init sections.
779 *
780 * Use the macro defined below instead of calling this directly.
781 */
782 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
783 struct module *owner, const char *mod_name);
784
785 /* use a define to avoid include chaining to get THIS_MODULE & friends */
786 #define usb_gadget_register_driver(driver) \
787 usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME)
788
789 /**
790 * usb_gadget_unregister_driver - unregister a gadget driver
791 * @driver:the driver being unregistered
792 * Context: can sleep
793 *
794 * Call this in your gadget driver's module cleanup function,
795 * to tell the underlying usb controller that your driver is
796 * going away. If the controller is connected to a USB host,
797 * it will first disconnect(). The driver is also requested
798 * to unbind() and clean up any device state, before this procedure
799 * finally returns. It's expected that the unbind() functions
800 * will be in exit sections, so may not be linked in some kernels.
801 */
802 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
803
804 /*-------------------------------------------------------------------------*/
805
806 /* utility to simplify dealing with string descriptors */
807
808 /**
809 * struct usb_string - wraps a C string and its USB id
810 * @id:the (nonzero) ID for this string
811 * @s:the string, in UTF-8 encoding
812 *
813 * If you're using usb_gadget_get_string(), use this to wrap a string
814 * together with its ID.
815 */
816 struct usb_string {
817 u8 id;
818 const char *s;
819 };
820
821 /**
822 * struct usb_gadget_strings - a set of USB strings in a given language
823 * @language:identifies the strings' language (0x0409 for en-us)
824 * @strings:array of strings with their ids
825 *
826 * If you're using usb_gadget_get_string(), use this to wrap all the
827 * strings for a given language.
828 */
829 struct usb_gadget_strings {
830 u16 language; /* 0x0409 for en-us */
831 struct usb_string *strings;
832 };
833
834 struct usb_gadget_string_container {
835 struct list_head list;
836 u8 *stash[];
837 };
838
839 /* put descriptor for string with that id into buf (buflen >= 256) */
840 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
841
842 /* check if the given language identifier is valid */
843 bool usb_validate_langid(u16 langid);
844
845 struct gadget_string {
846 struct config_item item;
847 struct list_head list;
848 char string[USB_MAX_STRING_LEN];
849 struct usb_string usb_string;
850 };
851
852 #define to_gadget_string(str_item)\
853 container_of(str_item, struct gadget_string, item)
854
855 /*-------------------------------------------------------------------------*/
856
857 /* utility to simplify managing config descriptors */
858
859 /* write vector of descriptors into buffer */
860 int usb_descriptor_fillbuf(void *, unsigned,
861 const struct usb_descriptor_header **);
862
863 /* build config descriptor from single descriptor vector */
864 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
865 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
866
867 /* copy a NULL-terminated vector of descriptors */
868 struct usb_descriptor_header **usb_copy_descriptors(
869 struct usb_descriptor_header **);
870
871 /**
872 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
873 * @v: vector of descriptors
874 */
875 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
876 {
877 kfree(v);
878 }
879
880 struct usb_function;
881 int usb_assign_descriptors(struct usb_function *f,
882 struct usb_descriptor_header **fs,
883 struct usb_descriptor_header **hs,
884 struct usb_descriptor_header **ss,
885 struct usb_descriptor_header **ssp);
886 void usb_free_all_descriptors(struct usb_function *f);
887
888 struct usb_descriptor_header *usb_otg_descriptor_alloc(
889 struct usb_gadget *gadget);
890 int usb_otg_descriptor_init(struct usb_gadget *gadget,
891 struct usb_descriptor_header *otg_desc);
892 /*-------------------------------------------------------------------------*/
893
894 /* utility to simplify map/unmap of usb_requests to/from DMA */
895
896 #ifdef CONFIG_HAS_DMA
897 extern int usb_gadget_map_request_by_dev(struct device *dev,
898 struct usb_request *req, int is_in);
899 extern int usb_gadget_map_request(struct usb_gadget *gadget,
900 struct usb_request *req, int is_in);
901
902 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
903 struct usb_request *req, int is_in);
904 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
905 struct usb_request *req, int is_in);
906 #else /* !CONFIG_HAS_DMA */
907 static inline int usb_gadget_map_request_by_dev(struct device *dev,
908 struct usb_request *req, int is_in) { return -ENOSYS; }
909 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
910 struct usb_request *req, int is_in) { return -ENOSYS; }
911
912 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
913 struct usb_request *req, int is_in) { }
914 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
915 struct usb_request *req, int is_in) { }
916 #endif /* !CONFIG_HAS_DMA */
917
918 /*-------------------------------------------------------------------------*/
919
920 /* utility to set gadget state properly */
921
922 extern void usb_gadget_set_state(struct usb_gadget *gadget,
923 enum usb_device_state state);
924
925 /*-------------------------------------------------------------------------*/
926
927 /* utility to tell udc core that the bus reset occurs */
928 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
929 struct usb_gadget_driver *driver);
930
931 /*-------------------------------------------------------------------------*/
932
933 /* utility to give requests back to the gadget layer */
934
935 extern void usb_gadget_giveback_request(struct usb_ep *ep,
936 struct usb_request *req);
937
938 /*-------------------------------------------------------------------------*/
939
940 /* utility to find endpoint by name */
941
942 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
943 const char *name);
944
945 /*-------------------------------------------------------------------------*/
946
947 /* utility to check if endpoint caps match descriptor needs */
948
949 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
950 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
951 struct usb_ss_ep_comp_descriptor *ep_comp);
952
953 /*-------------------------------------------------------------------------*/
954
955 /* utility to update vbus status for udc core, it may be scheduled */
956 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
957
958 /*-------------------------------------------------------------------------*/
959
960 /* utility wrapping a simple endpoint selection policy */
961
962 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
963 struct usb_endpoint_descriptor *);
964
965
966 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
967 struct usb_endpoint_descriptor *,
968 struct usb_ss_ep_comp_descriptor *);
969
970 extern void usb_ep_autoconfig_release(struct usb_ep *);
971
972 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
973
974 #endif /* __LINUX_USB_GADGET_H */
975
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