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