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 * This software is licensed under the GNU GPL version 2.
15 */
16
17 #ifndef __LINUX_USB_GADGET_H
18 #define __LINUX_USB_GADGET_H
19
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
32 struct usb_ep;
33
34 /**
35 * struct usb_request - describes one i/o request
36 * @buf: Buffer used for data. Always provide this; some controllers
37 * only use PIO, or don't use DMA for some endpoints.
38 * @dma: DMA address corresponding to 'buf'. If you don't set this
39 * field, and the usb controller needs one, it is responsible
40 * for mapping and unmapping the buffer.
41 * @sg: a scatterlist for SG-capable controllers.
42 * @num_sgs: number of SG entries
43 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
44 * @length: Length of that data
45 * @stream_id: The stream id, when USB3.0 bulk streams are being used
46 * @is_last: Indicates if this is the last request of a stream_id before
47 * switching to a different stream (required for DWC3 controllers).
48 * @no_interrupt: If true, hints that no completion irq is needed.
49 * Helpful sometimes with deep request queues that are handled
50 * directly by DMA controllers.
51 * @zero: If true, when writing data, makes the last packet be "short"
52 * by adding a zero length packet as needed;
53 * @short_not_ok: When reading data, makes short packets be
54 * treated as errors (queue stops advancing till cleanup).
55 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
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
116 void (*complete)(struct usb_ep *ep,
117 struct usb_request *req);
118 void *context;
119 struct list_head list;
120
121 unsigned frame_number; /* ISO ONLY */
122
123 int status;
124 unsigned actual;
125 };
126
127 /*-------------------------------------------------------------------------*/
128
129 /* endpoint-specific parts of the api to the usb controller hardware.
130 * unlike the urb model, (de)multiplexing layers are not required.
131 * (so this api could slash overhead if used on the host side...)
132 *
133 * note that device side usb controllers commonly differ in how many
134 * endpoints they support, as well as their capabilities.
135 */
136 struct usb_ep_ops {
137 int (*enable) (struct usb_ep *ep,
138 const struct usb_endpoint_descriptor *desc);
139 int (*disable) (struct usb_ep *ep);
140 void (*dispose) (struct usb_ep *ep);
141
142 struct usb_request *(*alloc_request) (struct usb_ep *ep,
143 gfp_t gfp_flags);
144 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
145
146 int (*queue) (struct usb_ep *ep, struct usb_request *req,
147 gfp_t gfp_flags);
148 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
149
150 int (*set_halt) (struct usb_ep *ep, int value);
151 int (*set_wedge) (struct usb_ep *ep);
152
153 int (*fifo_status) (struct usb_ep *ep);
154 void (*fifo_flush) (struct usb_ep *ep);
155 };
156
157 /**
158 * struct usb_ep_caps - endpoint capabilities description
159 * @type_control:Endpoint supports control type (reserved for ep0).
160 * @type_iso:Endpoint supports isochronous transfers.
161 * @type_bulk:Endpoint supports bulk transfers.
162 * @type_int:Endpoint supports interrupt transfers.
163 * @dir_in:Endpoint supports IN direction.
164 * @dir_out:Endpoint supports OUT direction.
165 */
166 struct usb_ep_caps {
167 unsigned type_control:1;
168 unsigned type_iso:1;
169 unsigned type_bulk:1;
170 unsigned type_int:1;
171 unsigned dir_in:1;
172 unsigned dir_out:1;
173 };
174
175 #define USB_EP_CAPS_TYPE_CONTROL 0x01
176 #define USB_EP_CAPS_TYPE_ISO 0x02
177 #define USB_EP_CAPS_TYPE_BULK 0x04
178 #define USB_EP_CAPS_TYPE_INT 0x08
179 #define USB_EP_CAPS_TYPE_ALL \
180 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
181 #define USB_EP_CAPS_DIR_IN 0x01
182 #define USB_EP_CAPS_DIR_OUT 0x02
183 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
184
185 #define USB_EP_CAPS(_type, _dir) \
186 { \
187 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
188 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
189 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
190 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
191 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
192 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
193 }
194
195 /**
196 * struct usb_ep - device side representation of USB endpoint
197 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
198 * @ops: Function pointers used to access hardware-specific operations.
199 * @ep_list:the gadget's ep_list holds all of its endpoints
200 * @caps:The structure describing types and directions supported by endoint.
201 * @enabled: The current endpoint enabled/disabled state.
202 * @claimed: True if this endpoint is claimed by a function.
203 * @maxpacket:The maximum packet size used on this endpoint. The initial
204 * value can sometimes be reduced (hardware allowing), according to
205 * the endpoint descriptor used to configure the endpoint.
206 * @maxpacket_limit:The maximum packet size value which can be handled by this
207 * endpoint. It's set once by UDC driver when endpoint is initialized, and
208 * should not be changed. Should not be confused with maxpacket.
209 * @max_streams: The maximum number of streams supported
210 * by this EP (0 - 16, actual number is 2^n)
211 * @mult: multiplier, 'mult' value for SS Isoc EPs
212 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
213 * @driver_data:for use by the gadget driver.
214 * @address: used to identify the endpoint when finding descriptor that
215 * matches connection speed
216 * @desc: endpoint descriptor. This pointer is set before the endpoint is
217 * enabled and remains valid until the endpoint is disabled.
218 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
219 * descriptor that is used to configure the endpoint
220 *
221 * the bus controller driver lists all the general purpose endpoints in
222 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
223 * and is accessed only in response to a driver setup() callback.
224 */
225
226 struct usb_ep {
227 void *driver_data;
228
229 const char *name;
230 const struct usb_ep_ops *ops;
231 struct list_head ep_list;
232 struct usb_ep_caps caps;
233 bool claimed;
234 bool enabled;
235 unsigned maxpacket:16;
236 unsigned maxpacket_limit:16;
237 unsigned max_streams:16;
238 unsigned mult:2;
239 unsigned maxburst:5;
240 u8 address;
241 const struct usb_endpoint_descriptor *desc;
242 const struct usb_ss_ep_comp_descriptor *comp_desc;
243 };
244
245 /*-------------------------------------------------------------------------*/
246
247 #if IS_ENABLED(CONFIG_USB_GADGET)
248 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
249 int usb_ep_enable(struct usb_ep *ep);
250 int usb_ep_disable(struct usb_ep *ep);
251 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
252 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
253 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
254 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
255 int usb_ep_set_halt(struct usb_ep *ep);
256 int usb_ep_clear_halt(struct usb_ep *ep);
257 int usb_ep_set_wedge(struct usb_ep *ep);
258 int usb_ep_fifo_status(struct usb_ep *ep);
259 void usb_ep_fifo_flush(struct usb_ep *ep);
260 #else
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)261 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
262 unsigned maxpacket_limit)
263 { }
usb_ep_enable(struct usb_ep * ep)264 static inline int usb_ep_enable(struct usb_ep *ep)
265 { return 0; }
usb_ep_disable(struct usb_ep * ep)266 static inline int usb_ep_disable(struct usb_ep *ep)
267 { return 0; }
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)268 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
269 gfp_t gfp_flags)
270 { return NULL; }
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)271 static inline void usb_ep_free_request(struct usb_ep *ep,
272 struct usb_request *req)
273 { }
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)274 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
275 gfp_t gfp_flags)
276 { return 0; }
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)277 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
278 { return 0; }
usb_ep_set_halt(struct usb_ep * ep)279 static inline int usb_ep_set_halt(struct usb_ep *ep)
280 { return 0; }
usb_ep_clear_halt(struct usb_ep * ep)281 static inline int usb_ep_clear_halt(struct usb_ep *ep)
282 { return 0; }
usb_ep_set_wedge(struct usb_ep * ep)283 static inline int usb_ep_set_wedge(struct usb_ep *ep)
284 { return 0; }
usb_ep_fifo_status(struct usb_ep * ep)285 static inline int usb_ep_fifo_status(struct usb_ep *ep)
286 { return 0; }
usb_ep_fifo_flush(struct usb_ep * ep)287 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
288 { }
289 #endif /* USB_GADGET */
290
291 /*-------------------------------------------------------------------------*/
292
293 struct usb_dcd_config_params {
294 __u8 bU1devExitLat; /* U1 Device exit Latency */
295 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
296 __le16 bU2DevExitLat; /* U2 Device exit Latency */
297 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
298 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */
299 __u8 besl_deep; /* Recommended deep BESL (0-15) */
300 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
301 };
302
303
304 struct usb_gadget;
305 struct usb_gadget_driver;
306 struct usb_udc;
307
308 /* the rest of the api to the controller hardware: device operations,
309 * which don't involve endpoints (or i/o).
310 */
311 struct usb_gadget_ops {
312 int (*get_frame)(struct usb_gadget *);
313 int (*wakeup)(struct usb_gadget *);
314 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
315 int (*vbus_session) (struct usb_gadget *, int is_active);
316 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
317 int (*pullup) (struct usb_gadget *, int is_on);
318 int (*ioctl)(struct usb_gadget *,
319 unsigned code, unsigned long param);
320 void (*get_config_params)(struct usb_gadget *,
321 struct usb_dcd_config_params *);
322 int (*udc_start)(struct usb_gadget *,
323 struct usb_gadget_driver *);
324 int (*udc_stop)(struct usb_gadget *);
325 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
326 struct usb_ep *(*match_ep)(struct usb_gadget *,
327 struct usb_endpoint_descriptor *,
328 struct usb_ss_ep_comp_descriptor *);
329 };
330
331 /**
332 * struct usb_gadget - represents a usb device
333 * @work: (internal use) Workqueue to be used for sysfs_notify()
334 * @udc: struct usb_udc pointer for this gadget
335 * @ops: Function pointers used to access hardware-specific operations.
336 * @ep0: Endpoint zero, used when reading or writing responses to
337 * driver setup() requests
338 * @ep_list: List of other endpoints supported by the device.
339 * @speed: Speed of current connection to USB host.
340 * @max_speed: Maximal speed the UDC can handle. UDC must support this
341 * and all slower speeds.
342 * @state: the state we are now (attached, suspended, configured, etc)
343 * @name: Identifies the controller hardware type. Used in diagnostics
344 * and sometimes configuration.
345 * @dev: Driver model state for this abstract device.
346 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
347 * @out_epnum: last used out ep number
348 * @in_epnum: last used in ep number
349 * @mA: last set mA value
350 * @otg_caps: OTG capabilities of this gadget.
351 * @sg_supported: true if we can handle scatter-gather
352 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
353 * gadget driver must provide a USB OTG descriptor.
354 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
355 * is in the Mini-AB jack, and HNP has been used to switch roles
356 * so that the "A" device currently acts as A-Peripheral, not A-Host.
357 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
358 * supports HNP at this port.
359 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
360 * only supports HNP on a different root port.
361 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
362 * enabled HNP support.
363 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
364 * in peripheral mode can support HNP polling.
365 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
366 * or B-Peripheral wants to take host role.
367 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
368 * MaxPacketSize.
369 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
370 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
371 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
372 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
373 * u_ether.c to improve performance.
374 * @is_selfpowered: if the gadget is self-powered.
375 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
376 * be connected.
377 * @connected: True if gadget is connected.
378 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
379 * indicates that it supports LPM as per the LPM ECN & errata.
380 * @irq: the interrupt number for device controller.
381 *
382 * Gadgets have a mostly-portable "gadget driver" implementing device
383 * functions, handling all usb configurations and interfaces. Gadget
384 * drivers talk to hardware-specific code indirectly, through ops vectors.
385 * That insulates the gadget driver from hardware details, and packages
386 * the hardware endpoints through generic i/o queues. The "usb_gadget"
387 * and "usb_ep" interfaces provide that insulation from the hardware.
388 *
389 * Except for the driver data, all fields in this structure are
390 * read-only to the gadget driver. That driver data is part of the
391 * "driver model" infrastructure in 2.6 (and later) kernels, and for
392 * earlier systems is grouped in a similar structure that's not known
393 * to the rest of the kernel.
394 *
395 * Values of the three OTG device feature flags are updated before the
396 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
397 * driver suspend() calls. They are valid only when is_otg, and when the
398 * device is acting as a B-Peripheral (so is_a_peripheral is false).
399 */
400 struct usb_gadget {
401 struct work_struct work;
402 struct usb_udc *udc;
403 /* readonly to gadget driver */
404 const struct usb_gadget_ops *ops;
405 struct usb_ep *ep0;
406 struct list_head ep_list; /* of usb_ep */
407 enum usb_device_speed speed;
408 enum usb_device_speed max_speed;
409 enum usb_device_state state;
410 const char *name;
411 struct device dev;
412 unsigned isoch_delay;
413 unsigned out_epnum;
414 unsigned in_epnum;
415 unsigned mA;
416 struct usb_otg_caps *otg_caps;
417
418 unsigned sg_supported:1;
419 unsigned is_otg:1;
420 unsigned is_a_peripheral:1;
421 unsigned b_hnp_enable:1;
422 unsigned a_hnp_support:1;
423 unsigned a_alt_hnp_support:1;
424 unsigned hnp_polling_support:1;
425 unsigned host_request_flag:1;
426 unsigned quirk_ep_out_aligned_size:1;
427 unsigned quirk_altset_not_supp:1;
428 unsigned quirk_stall_not_supp:1;
429 unsigned quirk_zlp_not_supp:1;
430 unsigned quirk_avoids_skb_reserve:1;
431 unsigned is_selfpowered:1;
432 unsigned deactivated:1;
433 unsigned connected:1;
434 unsigned lpm_capable:1;
435 int irq;
436 };
437 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
438
439 /* Interface to the device model */
set_gadget_data(struct usb_gadget * gadget,void * data)440 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
441 { dev_set_drvdata(&gadget->dev, data); }
get_gadget_data(struct usb_gadget * gadget)442 static inline void *get_gadget_data(struct usb_gadget *gadget)
443 { return dev_get_drvdata(&gadget->dev); }
dev_to_usb_gadget(struct device * dev)444 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
445 {
446 return container_of(dev, struct usb_gadget, dev);
447 }
usb_get_gadget(struct usb_gadget * gadget)448 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
449 {
450 get_device(&gadget->dev);
451 return gadget;
452 }
usb_put_gadget(struct usb_gadget * gadget)453 static inline void usb_put_gadget(struct usb_gadget *gadget)
454 {
455 put_device(&gadget->dev);
456 }
457 extern void usb_initialize_gadget(struct device *parent,
458 struct usb_gadget *gadget, void (*release)(struct device *dev));
459 extern int usb_add_gadget(struct usb_gadget *gadget);
460 extern void usb_del_gadget(struct usb_gadget *gadget);
461
462 /* Legacy device-model interface */
463 extern int usb_add_gadget_udc_release(struct device *parent,
464 struct usb_gadget *gadget, void (*release)(struct device *dev));
465 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
466 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
467 extern char *usb_get_gadget_udc_name(void);
468
469 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
470 #define gadget_for_each_ep(tmp, gadget) \
471 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
472
473 /**
474 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
475 * @ep: the endpoint whose maxpacketsize is used to align @len
476 * @len: buffer size's length to align to @ep's maxpacketsize
477 *
478 * This helper is used to align buffer's size to an ep's maxpacketsize.
479 */
usb_ep_align(struct usb_ep * ep,size_t len)480 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
481 {
482 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
483
484 return round_up(len, max_packet_size);
485 }
486
487 /**
488 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
489 * requires quirk_ep_out_aligned_size, otherwise returns len.
490 * @g: controller to check for quirk
491 * @ep: the endpoint whose maxpacketsize is used to align @len
492 * @len: buffer size's length to align to @ep's maxpacketsize
493 *
494 * This helper is used in case it's required for any reason to check and maybe
495 * align buffer's size to an ep's maxpacketsize.
496 */
497 static inline size_t
usb_ep_align_maybe(struct usb_gadget * g,struct usb_ep * ep,size_t len)498 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
499 {
500 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
501 }
502
503 /**
504 * gadget_is_altset_supported - return true iff the hardware supports
505 * altsettings
506 * @g: controller to check for quirk
507 */
gadget_is_altset_supported(struct usb_gadget * g)508 static inline int gadget_is_altset_supported(struct usb_gadget *g)
509 {
510 return !g->quirk_altset_not_supp;
511 }
512
513 /**
514 * gadget_is_stall_supported - return true iff the hardware supports stalling
515 * @g: controller to check for quirk
516 */
gadget_is_stall_supported(struct usb_gadget * g)517 static inline int gadget_is_stall_supported(struct usb_gadget *g)
518 {
519 return !g->quirk_stall_not_supp;
520 }
521
522 /**
523 * gadget_is_zlp_supported - return true iff the hardware supports zlp
524 * @g: controller to check for quirk
525 */
gadget_is_zlp_supported(struct usb_gadget * g)526 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
527 {
528 return !g->quirk_zlp_not_supp;
529 }
530
531 /**
532 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
533 * skb_reserve to improve performance.
534 * @g: controller to check for quirk
535 */
gadget_avoids_skb_reserve(struct usb_gadget * g)536 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
537 {
538 return g->quirk_avoids_skb_reserve;
539 }
540
541 /**
542 * gadget_is_dualspeed - return true iff the hardware handles high speed
543 * @g: controller that might support both high and full speeds
544 */
gadget_is_dualspeed(struct usb_gadget * g)545 static inline int gadget_is_dualspeed(struct usb_gadget *g)
546 {
547 return g->max_speed >= USB_SPEED_HIGH;
548 }
549
550 /**
551 * gadget_is_superspeed() - return true if the hardware handles superspeed
552 * @g: controller that might support superspeed
553 */
gadget_is_superspeed(struct usb_gadget * g)554 static inline int gadget_is_superspeed(struct usb_gadget *g)
555 {
556 return g->max_speed >= USB_SPEED_SUPER;
557 }
558
559 /**
560 * gadget_is_superspeed_plus() - return true if the hardware handles
561 * superspeed plus
562 * @g: controller that might support superspeed plus
563 */
gadget_is_superspeed_plus(struct usb_gadget * g)564 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
565 {
566 return g->max_speed >= USB_SPEED_SUPER_PLUS;
567 }
568
569 /**
570 * gadget_is_otg - return true iff the hardware is OTG-ready
571 * @g: controller that might have a Mini-AB connector
572 *
573 * This is a runtime test, since kernels with a USB-OTG stack sometimes
574 * run on boards which only have a Mini-B (or Mini-A) connector.
575 */
gadget_is_otg(struct usb_gadget * g)576 static inline int gadget_is_otg(struct usb_gadget *g)
577 {
578 #ifdef CONFIG_USB_OTG
579 return g->is_otg;
580 #else
581 return 0;
582 #endif
583 }
584
585 /*-------------------------------------------------------------------------*/
586
587 #if IS_ENABLED(CONFIG_USB_GADGET)
588 int usb_gadget_frame_number(struct usb_gadget *gadget);
589 int usb_gadget_wakeup(struct usb_gadget *gadget);
590 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
591 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
592 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
593 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
594 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
595 int usb_gadget_connect(struct usb_gadget *gadget);
596 int usb_gadget_disconnect(struct usb_gadget *gadget);
597 int usb_gadget_deactivate(struct usb_gadget *gadget);
598 int usb_gadget_activate(struct usb_gadget *gadget);
599 #else
usb_gadget_frame_number(struct usb_gadget * gadget)600 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
601 { return 0; }
usb_gadget_wakeup(struct usb_gadget * gadget)602 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
603 { return 0; }
usb_gadget_set_selfpowered(struct usb_gadget * gadget)604 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
605 { return 0; }
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)606 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
607 { return 0; }
usb_gadget_vbus_connect(struct usb_gadget * gadget)608 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
609 { return 0; }
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)610 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
611 { return 0; }
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)612 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
613 { return 0; }
usb_gadget_connect(struct usb_gadget * gadget)614 static inline int usb_gadget_connect(struct usb_gadget *gadget)
615 { return 0; }
usb_gadget_disconnect(struct usb_gadget * gadget)616 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
617 { return 0; }
usb_gadget_deactivate(struct usb_gadget * gadget)618 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
619 { return 0; }
usb_gadget_activate(struct usb_gadget * gadget)620 static inline int usb_gadget_activate(struct usb_gadget *gadget)
621 { return 0; }
622 #endif /* CONFIG_USB_GADGET */
623
624 /*-------------------------------------------------------------------------*/
625
626 /**
627 * struct usb_gadget_driver - driver for usb gadget devices
628 * @function: String describing the gadget's function
629 * @max_speed: Highest speed the driver handles.
630 * @setup: Invoked for ep0 control requests that aren't handled by
631 * the hardware level driver. Most calls must be handled by
632 * the gadget driver, including descriptor and configuration
633 * management. The 16 bit members of the setup data are in
634 * USB byte order. Called in_interrupt; this may not sleep. Driver
635 * queues a response to ep0, or returns negative to stall.
636 * @disconnect: Invoked after all transfers have been stopped,
637 * when the host is disconnected. May be called in_interrupt; this
638 * may not sleep. Some devices can't detect disconnect, so this might
639 * not be called except as part of controller shutdown.
640 * @bind: the driver's bind callback
641 * @unbind: Invoked when the driver is unbound from a gadget,
642 * usually from rmmod (after a disconnect is reported).
643 * Called in a context that permits sleeping.
644 * @suspend: Invoked on USB suspend. May be called in_interrupt.
645 * @resume: Invoked on USB resume. May be called in_interrupt.
646 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
647 * and should be called in_interrupt.
648 * @driver: Driver model state for this driver.
649 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
650 * this driver will be bound to any available UDC.
651 * @pending: UDC core private data used for deferred probe of this driver.
652 * @match_existing_only: If udc is not found, return an error and don't add this
653 * gadget driver to list of pending driver
654 *
655 * Devices are disabled till a gadget driver successfully bind()s, which
656 * means the driver will handle setup() requests needed to enumerate (and
657 * meet "chapter 9" requirements) then do some useful work.
658 *
659 * If gadget->is_otg is true, the gadget driver must provide an OTG
660 * descriptor during enumeration, or else fail the bind() call. In such
661 * cases, no USB traffic may flow until both bind() returns without
662 * having called usb_gadget_disconnect(), and the USB host stack has
663 * initialized.
664 *
665 * Drivers use hardware-specific knowledge to configure the usb hardware.
666 * endpoint addressing is only one of several hardware characteristics that
667 * are in descriptors the ep0 implementation returns from setup() calls.
668 *
669 * Except for ep0 implementation, most driver code shouldn't need change to
670 * run on top of different usb controllers. It'll use endpoints set up by
671 * that ep0 implementation.
672 *
673 * The usb controller driver handles a few standard usb requests. Those
674 * include set_address, and feature flags for devices, interfaces, and
675 * endpoints (the get_status, set_feature, and clear_feature requests).
676 *
677 * Accordingly, the driver's setup() callback must always implement all
678 * get_descriptor requests, returning at least a device descriptor and
679 * a configuration descriptor. Drivers must make sure the endpoint
680 * descriptors match any hardware constraints. Some hardware also constrains
681 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
682 *
683 * The driver's setup() callback must also implement set_configuration,
684 * and should also implement set_interface, get_configuration, and
685 * get_interface. Setting a configuration (or interface) is where
686 * endpoints should be activated or (config 0) shut down.
687 *
688 * (Note that only the default control endpoint is supported. Neither
689 * hosts nor devices generally support control traffic except to ep0.)
690 *
691 * Most devices will ignore USB suspend/resume operations, and so will
692 * not provide those callbacks. However, some may need to change modes
693 * when the host is not longer directing those activities. For example,
694 * local controls (buttons, dials, etc) may need to be re-enabled since
695 * the (remote) host can't do that any longer; or an error state might
696 * be cleared, to make the device behave identically whether or not
697 * power is maintained.
698 */
699 struct usb_gadget_driver {
700 char *function;
701 enum usb_device_speed max_speed;
702 int (*bind)(struct usb_gadget *gadget,
703 struct usb_gadget_driver *driver);
704 void (*unbind)(struct usb_gadget *);
705 int (*setup)(struct usb_gadget *,
706 const struct usb_ctrlrequest *);
707 void (*disconnect)(struct usb_gadget *);
708 void (*suspend)(struct usb_gadget *);
709 void (*resume)(struct usb_gadget *);
710 void (*reset)(struct usb_gadget *);
711
712 /* FIXME support safe rmmod */
713 struct device_driver driver;
714
715 char *udc_name;
716 struct list_head pending;
717 unsigned match_existing_only:1;
718 };
719
720
721
722 /*-------------------------------------------------------------------------*/
723
724 /* driver modules register and unregister, as usual.
725 * these calls must be made in a context that can sleep.
726 *
727 * these will usually be implemented directly by the hardware-dependent
728 * usb bus interface driver, which will only support a single driver.
729 */
730
731 /**
732 * usb_gadget_probe_driver - probe a gadget driver
733 * @driver: the driver being registered
734 * Context: can sleep
735 *
736 * Call this in your gadget driver's module initialization function,
737 * to tell the underlying usb controller driver about your driver.
738 * The @bind() function will be called to bind it to a gadget before this
739 * registration call returns. It's expected that the @bind() function will
740 * be in init sections.
741 */
742 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
743
744 /**
745 * usb_gadget_unregister_driver - unregister a gadget driver
746 * @driver:the driver being unregistered
747 * Context: can sleep
748 *
749 * Call this in your gadget driver's module cleanup function,
750 * to tell the underlying usb controller that your driver is
751 * going away. If the controller is connected to a USB host,
752 * it will first disconnect(). The driver is also requested
753 * to unbind() and clean up any device state, before this procedure
754 * finally returns. It's expected that the unbind() functions
755 * will be in exit sections, so may not be linked in some kernels.
756 */
757 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
758
759 /*-------------------------------------------------------------------------*/
760
761 /* utility to simplify dealing with string descriptors */
762
763 /**
764 * struct usb_string - wraps a C string and its USB id
765 * @id:the (nonzero) ID for this string
766 * @s:the string, in UTF-8 encoding
767 *
768 * If you're using usb_gadget_get_string(), use this to wrap a string
769 * together with its ID.
770 */
771 struct usb_string {
772 u8 id;
773 const char *s;
774 };
775
776 /**
777 * struct usb_gadget_strings - a set of USB strings in a given language
778 * @language:identifies the strings' language (0x0409 for en-us)
779 * @strings:array of strings with their ids
780 *
781 * If you're using usb_gadget_get_string(), use this to wrap all the
782 * strings for a given language.
783 */
784 struct usb_gadget_strings {
785 u16 language; /* 0x0409 for en-us */
786 struct usb_string *strings;
787 };
788
789 struct usb_gadget_string_container {
790 struct list_head list;
791 u8 *stash[];
792 };
793
794 /* put descriptor for string with that id into buf (buflen >= 256) */
795 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
796
797 /* check if the given language identifier is valid */
798 bool usb_validate_langid(u16 langid);
799
800 /*-------------------------------------------------------------------------*/
801
802 /* utility to simplify managing config descriptors */
803
804 /* write vector of descriptors into buffer */
805 int usb_descriptor_fillbuf(void *, unsigned,
806 const struct usb_descriptor_header **);
807
808 /* build config descriptor from single descriptor vector */
809 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
810 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
811
812 /* copy a NULL-terminated vector of descriptors */
813 struct usb_descriptor_header **usb_copy_descriptors(
814 struct usb_descriptor_header **);
815
816 /**
817 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
818 * @v: vector of descriptors
819 */
usb_free_descriptors(struct usb_descriptor_header ** v)820 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
821 {
822 kfree(v);
823 }
824
825 struct usb_function;
826 int usb_assign_descriptors(struct usb_function *f,
827 struct usb_descriptor_header **fs,
828 struct usb_descriptor_header **hs,
829 struct usb_descriptor_header **ss,
830 struct usb_descriptor_header **ssp);
831 void usb_free_all_descriptors(struct usb_function *f);
832
833 struct usb_descriptor_header *usb_otg_descriptor_alloc(
834 struct usb_gadget *gadget);
835 int usb_otg_descriptor_init(struct usb_gadget *gadget,
836 struct usb_descriptor_header *otg_desc);
837 /*-------------------------------------------------------------------------*/
838
839 /* utility to simplify map/unmap of usb_requests to/from DMA */
840
841 #ifdef CONFIG_HAS_DMA
842 extern int usb_gadget_map_request_by_dev(struct device *dev,
843 struct usb_request *req, int is_in);
844 extern int usb_gadget_map_request(struct usb_gadget *gadget,
845 struct usb_request *req, int is_in);
846
847 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
848 struct usb_request *req, int is_in);
849 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
850 struct usb_request *req, int is_in);
851 #else /* !CONFIG_HAS_DMA */
usb_gadget_map_request_by_dev(struct device * dev,struct usb_request * req,int is_in)852 static inline int usb_gadget_map_request_by_dev(struct device *dev,
853 struct usb_request *req, int is_in) { return -ENOSYS; }
usb_gadget_map_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)854 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
855 struct usb_request *req, int is_in) { return -ENOSYS; }
856
usb_gadget_unmap_request_by_dev(struct device * dev,struct usb_request * req,int is_in)857 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
858 struct usb_request *req, int is_in) { }
usb_gadget_unmap_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)859 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
860 struct usb_request *req, int is_in) { }
861 #endif /* !CONFIG_HAS_DMA */
862
863 /*-------------------------------------------------------------------------*/
864
865 /* utility to set gadget state properly */
866
867 extern void usb_gadget_set_state(struct usb_gadget *gadget,
868 enum usb_device_state state);
869
870 /*-------------------------------------------------------------------------*/
871
872 /* utility to tell udc core that the bus reset occurs */
873 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
874 struct usb_gadget_driver *driver);
875
876 /*-------------------------------------------------------------------------*/
877
878 /* utility to give requests back to the gadget layer */
879
880 extern void usb_gadget_giveback_request(struct usb_ep *ep,
881 struct usb_request *req);
882
883 /*-------------------------------------------------------------------------*/
884
885 /* utility to find endpoint by name */
886
887 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
888 const char *name);
889
890 /*-------------------------------------------------------------------------*/
891
892 /* utility to check if endpoint caps match descriptor needs */
893
894 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
895 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
896 struct usb_ss_ep_comp_descriptor *ep_comp);
897
898 /*-------------------------------------------------------------------------*/
899
900 /* utility to update vbus status for udc core, it may be scheduled */
901 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
902
903 /*-------------------------------------------------------------------------*/
904
905 /* utility wrapping a simple endpoint selection policy */
906
907 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
908 struct usb_endpoint_descriptor *);
909
910
911 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
912 struct usb_endpoint_descriptor *,
913 struct usb_ss_ep_comp_descriptor *);
914
915 extern void usb_ep_autoconfig_release(struct usb_ep *);
916
917 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
918
919 #endif /* __LINUX_USB_GADGET_H */
920