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 #include <linux/android_kabi.h>
30
31 #define UDC_TRACE_STR_MAX 512
32
33 struct usb_ep;
34
35 /**
36 * struct usb_request - describes one i/o request
37 * @buf: Buffer used for data. Always provide this; some controllers
38 * only use PIO, or don't use DMA for some endpoints.
39 * @dma: DMA address corresponding to 'buf'. If you don't set this
40 * field, and the usb controller needs one, it is responsible
41 * for mapping and unmapping the buffer.
42 * @sg: a scatterlist for SG-capable controllers.
43 * @num_sgs: number of SG entries
44 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
45 * @length: Length of that data
46 * @stream_id: The stream id, when USB3.0 bulk streams are being used
47 * @is_last: Indicates if this is the last request of a stream_id before
48 * switching to a different stream (required for DWC3 controllers).
49 * @no_interrupt: If true, hints that no completion irq is needed.
50 * Helpful sometimes with deep request queues that are handled
51 * directly by DMA controllers.
52 * @zero: If true, when writing data, makes the last packet be "short"
53 * by adding a zero length packet as needed;
54 * @short_not_ok: When reading data, makes short packets be
55 * treated as errors (queue stops advancing till cleanup).
56 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
57 * @complete: Function called when request completes, so this request and
58 * its buffer may be re-used. The function will always be called with
59 * interrupts disabled, and it must not sleep.
60 * Reads terminate with a short packet, or when the buffer fills,
61 * whichever comes first. When writes terminate, some data bytes
62 * will usually still be in flight (often in a hardware fifo).
63 * Errors (for reads or writes) stop the queue from advancing
64 * until the completion function returns, so that any transfers
65 * invalidated by the error may first be dequeued.
66 * @context: For use by the completion callback
67 * @list: For use by the gadget driver.
68 * @frame_number: Reports the interval number in (micro)frame in which the
69 * isochronous transfer was transmitted or received.
70 * @status: Reports completion code, zero or a negative errno.
71 * Normally, faults block the transfer queue from advancing until
72 * the completion callback returns.
73 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
74 * or when the driver disabled the endpoint.
75 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
76 * transfers) this may be less than the requested length. If the
77 * short_not_ok flag is set, short reads are treated as errors
78 * even when status otherwise indicates successful completion.
79 * Note that for writes (IN transfers) some data bytes may still
80 * reside in a device-side FIFO when the request is reported as
81 * complete.
82 *
83 * These are allocated/freed through the endpoint they're used with. The
84 * hardware's driver can add extra per-request data to the memory it returns,
85 * which often avoids separate memory allocations (potential failures),
86 * later when the request is queued.
87 *
88 * Request flags affect request handling, such as whether a zero length
89 * packet is written (the "zero" flag), whether a short read should be
90 * treated as an error (blocking request queue advance, the "short_not_ok"
91 * flag), or hinting that an interrupt is not required (the "no_interrupt"
92 * flag, for use with deep request queues).
93 *
94 * Bulk endpoints can use any size buffers, and can also be used for interrupt
95 * transfers. interrupt-only endpoints can be much less functional.
96 *
97 * NOTE: this is analogous to 'struct urb' on the host side, except that
98 * it's thinner and promotes more pre-allocation.
99 */
100
101 struct usb_request {
102 void *buf;
103 unsigned length;
104 dma_addr_t dma;
105
106 struct scatterlist *sg;
107 unsigned num_sgs;
108 unsigned num_mapped_sgs;
109
110 unsigned stream_id:16;
111 unsigned is_last:1;
112 unsigned no_interrupt:1;
113 unsigned zero:1;
114 unsigned short_not_ok:1;
115 unsigned dma_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 ANDROID_KABI_RESERVE(1);
128 };
129
130 /*-------------------------------------------------------------------------*/
131
132 /* endpoint-specific parts of the api to the usb controller hardware.
133 * unlike the urb model, (de)multiplexing layers are not required.
134 * (so this api could slash overhead if used on the host side...)
135 *
136 * note that device side usb controllers commonly differ in how many
137 * endpoints they support, as well as their capabilities.
138 */
139 struct usb_ep_ops {
140 int (*enable) (struct usb_ep *ep,
141 const struct usb_endpoint_descriptor *desc);
142 int (*disable) (struct usb_ep *ep);
143 void (*dispose) (struct usb_ep *ep);
144
145 struct usb_request *(*alloc_request) (struct usb_ep *ep,
146 gfp_t gfp_flags);
147 void (*free_request) (struct usb_ep *ep, struct usb_request *req);
148
149 int (*queue) (struct usb_ep *ep, struct usb_request *req,
150 gfp_t gfp_flags);
151 int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
152
153 int (*set_halt) (struct usb_ep *ep, int value);
154 int (*set_wedge) (struct usb_ep *ep);
155
156 int (*fifo_status) (struct usb_ep *ep);
157 void (*fifo_flush) (struct usb_ep *ep);
158
159 ANDROID_KABI_RESERVE(1);
160 };
161
162 /**
163 * struct usb_ep_caps - endpoint capabilities description
164 * @type_control:Endpoint supports control type (reserved for ep0).
165 * @type_iso:Endpoint supports isochronous transfers.
166 * @type_bulk:Endpoint supports bulk transfers.
167 * @type_int:Endpoint supports interrupt transfers.
168 * @dir_in:Endpoint supports IN direction.
169 * @dir_out:Endpoint supports OUT direction.
170 */
171 struct usb_ep_caps {
172 unsigned type_control:1;
173 unsigned type_iso:1;
174 unsigned type_bulk:1;
175 unsigned type_int:1;
176 unsigned dir_in:1;
177 unsigned dir_out:1;
178 };
179
180 #define USB_EP_CAPS_TYPE_CONTROL 0x01
181 #define USB_EP_CAPS_TYPE_ISO 0x02
182 #define USB_EP_CAPS_TYPE_BULK 0x04
183 #define USB_EP_CAPS_TYPE_INT 0x08
184 #define USB_EP_CAPS_TYPE_ALL \
185 (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
186 #define USB_EP_CAPS_DIR_IN 0x01
187 #define USB_EP_CAPS_DIR_OUT 0x02
188 #define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
189
190 #define USB_EP_CAPS(_type, _dir) \
191 { \
192 .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
193 .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
194 .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
195 .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
196 .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
197 .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
198 }
199
200 /**
201 * struct usb_ep - device side representation of USB endpoint
202 * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
203 * @ops: Function pointers used to access hardware-specific operations.
204 * @ep_list:the gadget's ep_list holds all of its endpoints
205 * @caps:The structure describing types and directions supported by endoint.
206 * @enabled: The current endpoint enabled/disabled state.
207 * @claimed: True if this endpoint is claimed by a function.
208 * @maxpacket:The maximum packet size used on this endpoint. The initial
209 * value can sometimes be reduced (hardware allowing), according to
210 * the endpoint descriptor used to configure the endpoint.
211 * @maxpacket_limit:The maximum packet size value which can be handled by this
212 * endpoint. It's set once by UDC driver when endpoint is initialized, and
213 * should not be changed. Should not be confused with maxpacket.
214 * @max_streams: The maximum number of streams supported
215 * by this EP (0 - 16, actual number is 2^n)
216 * @mult: multiplier, 'mult' value for SS Isoc EPs
217 * @maxburst: the maximum number of bursts supported by this EP (for usb3)
218 * @driver_data:for use by the gadget driver.
219 * @address: used to identify the endpoint when finding descriptor that
220 * matches connection speed
221 * @desc: endpoint descriptor. This pointer is set before the endpoint is
222 * enabled and remains valid until the endpoint is disabled.
223 * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
224 * descriptor that is used to configure the endpoint
225 * @transfer_type: Used to specify transfer type of EP.
226 *
227 * the bus controller driver lists all the general purpose endpoints in
228 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
229 * and is accessed only in response to a driver setup() callback.
230 */
231
232 struct usb_ep {
233 void *driver_data;
234
235 const char *name;
236 const struct usb_ep_ops *ops;
237 struct list_head ep_list;
238 struct usb_ep_caps caps;
239 bool claimed;
240 bool enabled;
241 unsigned maxpacket:16;
242 unsigned maxpacket_limit:16;
243 unsigned max_streams:16;
244 unsigned mult:2;
245 unsigned maxburst:5;
246 u8 address;
247 const struct usb_endpoint_descriptor *desc;
248 const struct usb_ss_ep_comp_descriptor *comp_desc;
249 #if defined(CONFIG_ARCH_ROCKCHIP) && defined(CONFIG_NO_GKI)
250 u8 transfer_type;
251 #endif
252
253 ANDROID_KABI_RESERVE(1);
254 };
255
256 /*-------------------------------------------------------------------------*/
257
258 #if IS_ENABLED(CONFIG_USB_GADGET)
259 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
260 int usb_ep_enable(struct usb_ep *ep);
261 int usb_ep_disable(struct usb_ep *ep);
262 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
263 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
264 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
265 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
266 int usb_ep_set_halt(struct usb_ep *ep);
267 int usb_ep_clear_halt(struct usb_ep *ep);
268 int usb_ep_set_wedge(struct usb_ep *ep);
269 int usb_ep_fifo_status(struct usb_ep *ep);
270 void usb_ep_fifo_flush(struct usb_ep *ep);
271 #else
usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit)272 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
273 unsigned maxpacket_limit)
274 { }
usb_ep_enable(struct usb_ep *ep)275 static inline int usb_ep_enable(struct usb_ep *ep)
276 { return 0; }
usb_ep_disable(struct usb_ep *ep)277 static inline int usb_ep_disable(struct usb_ep *ep)
278 { return 0; }
usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)279 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
280 gfp_t gfp_flags)
281 { return NULL; }
usb_ep_free_request(struct usb_ep *ep, struct usb_request *req)282 static inline void usb_ep_free_request(struct usb_ep *ep,
283 struct usb_request *req)
284 { }
usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags)285 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
286 gfp_t gfp_flags)
287 { return 0; }
usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)288 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
289 { return 0; }
usb_ep_set_halt(struct usb_ep *ep)290 static inline int usb_ep_set_halt(struct usb_ep *ep)
291 { return 0; }
usb_ep_clear_halt(struct usb_ep *ep)292 static inline int usb_ep_clear_halt(struct usb_ep *ep)
293 { return 0; }
usb_ep_set_wedge(struct usb_ep *ep)294 static inline int usb_ep_set_wedge(struct usb_ep *ep)
295 { return 0; }
usb_ep_fifo_status(struct usb_ep *ep)296 static inline int usb_ep_fifo_status(struct usb_ep *ep)
297 { return 0; }
usb_ep_fifo_flush(struct usb_ep *ep)298 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
299 { }
300 #endif /* USB_GADGET */
301
302 /*-------------------------------------------------------------------------*/
303
304 struct usb_dcd_config_params {
305 __u8 bU1devExitLat; /* U1 Device exit Latency */
306 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
307 __le16 bU2DevExitLat; /* U2 Device exit Latency */
308 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
309 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */
310 __u8 besl_deep; /* Recommended deep BESL (0-15) */
311 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
312 };
313
314
315 struct usb_gadget;
316 struct usb_gadget_driver;
317 struct usb_udc;
318
319 /* the rest of the api to the controller hardware: device operations,
320 * which don't involve endpoints (or i/o).
321 */
322 struct usb_gadget_ops {
323 int (*get_frame)(struct usb_gadget *);
324 int (*wakeup)(struct usb_gadget *);
325 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
326 int (*vbus_session) (struct usb_gadget *, int is_active);
327 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
328 int (*pullup) (struct usb_gadget *, int is_on);
329 int (*ioctl)(struct usb_gadget *,
330 unsigned code, unsigned long param);
331 void (*get_config_params)(struct usb_gadget *,
332 struct usb_dcd_config_params *);
333 int (*udc_start)(struct usb_gadget *,
334 struct usb_gadget_driver *);
335 int (*udc_stop)(struct usb_gadget *);
336 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
337 void (*udc_set_ssp_rate)(struct usb_gadget *gadget,
338 enum usb_ssp_rate rate);
339 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
340 struct usb_ep *(*match_ep)(struct usb_gadget *,
341 struct usb_endpoint_descriptor *,
342 struct usb_ss_ep_comp_descriptor *);
343 int (*check_config)(struct usb_gadget *gadget);
344
345 ANDROID_KABI_RESERVE(1);
346 ANDROID_KABI_RESERVE(2);
347 ANDROID_KABI_RESERVE(3);
348 ANDROID_KABI_RESERVE(4);
349 };
350
351 /**
352 * struct usb_gadget - represents a usb device
353 * @work: (internal use) Workqueue to be used for sysfs_notify()
354 * @udc: struct usb_udc pointer for this gadget
355 * @ops: Function pointers used to access hardware-specific operations.
356 * @ep0: Endpoint zero, used when reading or writing responses to
357 * driver setup() requests
358 * @ep_list: List of other endpoints supported by the device.
359 * @speed: Speed of current connection to USB host.
360 * @max_speed: Maximal speed the UDC can handle. UDC must support this
361 * and all slower speeds.
362 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
363 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
364 * can handle. The UDC must support this and all slower speeds and lower
365 * number of lanes.
366 * @state: the state we are now (attached, suspended, configured, etc)
367 * @name: Identifies the controller hardware type. Used in diagnostics
368 * and sometimes configuration.
369 * @dev: Driver model state for this abstract device.
370 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
371 * @out_epnum: last used out ep number
372 * @in_epnum: last used in ep number
373 * @mA: last set mA value
374 * @otg_caps: OTG capabilities of this gadget.
375 * @sg_supported: true if we can handle scatter-gather
376 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
377 * gadget driver must provide a USB OTG descriptor.
378 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
379 * is in the Mini-AB jack, and HNP has been used to switch roles
380 * so that the "A" device currently acts as A-Peripheral, not A-Host.
381 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
382 * supports HNP at this port.
383 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
384 * only supports HNP on a different root port.
385 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
386 * enabled HNP support.
387 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
388 * in peripheral mode can support HNP polling.
389 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
390 * or B-Peripheral wants to take host role.
391 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
392 * MaxPacketSize.
393 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
394 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
395 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
396 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
397 * u_ether.c to improve performance.
398 * @is_selfpowered: if the gadget is self-powered.
399 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
400 * be connected.
401 * @connected: True if gadget is connected.
402 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
403 * indicates that it supports LPM as per the LPM ECN & errata.
404 * @irq: the interrupt number for device controller.
405 *
406 * Gadgets have a mostly-portable "gadget driver" implementing device
407 * functions, handling all usb configurations and interfaces. Gadget
408 * drivers talk to hardware-specific code indirectly, through ops vectors.
409 * That insulates the gadget driver from hardware details, and packages
410 * the hardware endpoints through generic i/o queues. The "usb_gadget"
411 * and "usb_ep" interfaces provide that insulation from the hardware.
412 *
413 * Except for the driver data, all fields in this structure are
414 * read-only to the gadget driver. That driver data is part of the
415 * "driver model" infrastructure in 2.6 (and later) kernels, and for
416 * earlier systems is grouped in a similar structure that's not known
417 * to the rest of the kernel.
418 *
419 * Values of the three OTG device feature flags are updated before the
420 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
421 * driver suspend() calls. They are valid only when is_otg, and when the
422 * device is acting as a B-Peripheral (so is_a_peripheral is false).
423 */
424 struct usb_gadget {
425 struct work_struct work;
426 struct usb_udc *udc;
427 /* readonly to gadget driver */
428 const struct usb_gadget_ops *ops;
429 struct usb_ep *ep0;
430 struct list_head ep_list; /* of usb_ep */
431 enum usb_device_speed speed;
432 enum usb_device_speed max_speed;
433
434 /* USB SuperSpeed Plus only */
435 enum usb_ssp_rate ssp_rate;
436 enum usb_ssp_rate max_ssp_rate;
437
438 enum usb_device_state state;
439 const char *name;
440 struct device dev;
441 unsigned isoch_delay;
442 unsigned out_epnum;
443 unsigned in_epnum;
444 unsigned mA;
445 struct usb_otg_caps *otg_caps;
446
447 unsigned sg_supported:1;
448 unsigned is_otg:1;
449 unsigned is_a_peripheral:1;
450 unsigned b_hnp_enable:1;
451 unsigned a_hnp_support:1;
452 unsigned a_alt_hnp_support:1;
453 unsigned hnp_polling_support:1;
454 unsigned host_request_flag:1;
455 unsigned quirk_ep_out_aligned_size:1;
456 unsigned quirk_altset_not_supp:1;
457 unsigned quirk_stall_not_supp:1;
458 unsigned quirk_zlp_not_supp:1;
459 unsigned quirk_avoids_skb_reserve:1;
460 unsigned is_selfpowered:1;
461 unsigned deactivated:1;
462 unsigned connected:1;
463 unsigned lpm_capable:1;
464 int irq;
465
466 ANDROID_KABI_RESERVE(1);
467 ANDROID_KABI_RESERVE(2);
468 ANDROID_KABI_RESERVE(3);
469 ANDROID_KABI_RESERVE(4);
470 };
471 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
472
473 /* Interface to the device model */
set_gadget_data(struct usb_gadget *gadget, void *data)474 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
475 { dev_set_drvdata(&gadget->dev, data); }
get_gadget_data(struct usb_gadget *gadget)476 static inline void *get_gadget_data(struct usb_gadget *gadget)
477 { return dev_get_drvdata(&gadget->dev); }
dev_to_usb_gadget(struct device *dev)478 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
479 {
480 return container_of(dev, struct usb_gadget, dev);
481 }
usb_get_gadget(struct usb_gadget *gadget)482 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
483 {
484 get_device(&gadget->dev);
485 return gadget;
486 }
usb_put_gadget(struct usb_gadget *gadget)487 static inline void usb_put_gadget(struct usb_gadget *gadget)
488 {
489 put_device(&gadget->dev);
490 }
491 extern void usb_initialize_gadget(struct device *parent,
492 struct usb_gadget *gadget, void (*release)(struct device *dev));
493 extern int usb_add_gadget(struct usb_gadget *gadget);
494 extern void usb_del_gadget(struct usb_gadget *gadget);
495
496 /* Legacy device-model interface */
497 extern int usb_add_gadget_udc_release(struct device *parent,
498 struct usb_gadget *gadget, void (*release)(struct device *dev));
499 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
500 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
501 extern char *usb_get_gadget_udc_name(void);
502
503 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
504 #define gadget_for_each_ep(tmp, gadget) \
505 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
506
507 /**
508 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
509 * @ep: the endpoint whose maxpacketsize is used to align @len
510 * @len: buffer size's length to align to @ep's maxpacketsize
511 *
512 * This helper is used to align buffer's size to an ep's maxpacketsize.
513 */
usb_ep_align(struct usb_ep *ep, size_t len)514 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
515 {
516 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
517
518 return round_up(len, max_packet_size);
519 }
520
521 /**
522 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
523 * requires quirk_ep_out_aligned_size, otherwise returns len.
524 * @g: controller to check for quirk
525 * @ep: the endpoint whose maxpacketsize is used to align @len
526 * @len: buffer size's length to align to @ep's maxpacketsize
527 *
528 * This helper is used in case it's required for any reason to check and maybe
529 * align buffer's size to an ep's maxpacketsize.
530 */
531 static inline size_t
usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)532 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
533 {
534 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
535 }
536
537 /**
538 * gadget_is_altset_supported - return true iff the hardware supports
539 * altsettings
540 * @g: controller to check for quirk
541 */
gadget_is_altset_supported(struct usb_gadget *g)542 static inline int gadget_is_altset_supported(struct usb_gadget *g)
543 {
544 return !g->quirk_altset_not_supp;
545 }
546
547 /**
548 * gadget_is_stall_supported - return true iff the hardware supports stalling
549 * @g: controller to check for quirk
550 */
gadget_is_stall_supported(struct usb_gadget *g)551 static inline int gadget_is_stall_supported(struct usb_gadget *g)
552 {
553 return !g->quirk_stall_not_supp;
554 }
555
556 /**
557 * gadget_is_zlp_supported - return true iff the hardware supports zlp
558 * @g: controller to check for quirk
559 */
gadget_is_zlp_supported(struct usb_gadget *g)560 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
561 {
562 return !g->quirk_zlp_not_supp;
563 }
564
565 /**
566 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
567 * skb_reserve to improve performance.
568 * @g: controller to check for quirk
569 */
gadget_avoids_skb_reserve(struct usb_gadget *g)570 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
571 {
572 return g->quirk_avoids_skb_reserve;
573 }
574
575 /**
576 * gadget_is_dualspeed - return true iff the hardware handles high speed
577 * @g: controller that might support both high and full speeds
578 */
gadget_is_dualspeed(struct usb_gadget *g)579 static inline int gadget_is_dualspeed(struct usb_gadget *g)
580 {
581 return g->max_speed >= USB_SPEED_HIGH;
582 }
583
584 /**
585 * gadget_is_superspeed() - return true if the hardware handles superspeed
586 * @g: controller that might support superspeed
587 */
gadget_is_superspeed(struct usb_gadget *g)588 static inline int gadget_is_superspeed(struct usb_gadget *g)
589 {
590 return g->max_speed >= USB_SPEED_SUPER;
591 }
592
593 /**
594 * gadget_is_superspeed_plus() - return true if the hardware handles
595 * superspeed plus
596 * @g: controller that might support superspeed plus
597 */
gadget_is_superspeed_plus(struct usb_gadget *g)598 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
599 {
600 return g->max_speed >= USB_SPEED_SUPER_PLUS;
601 }
602
603 /**
604 * gadget_is_otg - return true iff the hardware is OTG-ready
605 * @g: controller that might have a Mini-AB connector
606 *
607 * This is a runtime test, since kernels with a USB-OTG stack sometimes
608 * run on boards which only have a Mini-B (or Mini-A) connector.
609 */
gadget_is_otg(struct usb_gadget *g)610 static inline int gadget_is_otg(struct usb_gadget *g)
611 {
612 #ifdef CONFIG_USB_OTG
613 return g->is_otg;
614 #else
615 return 0;
616 #endif
617 }
618
619 /*-------------------------------------------------------------------------*/
620
621 #if IS_ENABLED(CONFIG_USB_GADGET)
622 int usb_gadget_frame_number(struct usb_gadget *gadget);
623 int usb_gadget_wakeup(struct usb_gadget *gadget);
624 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
625 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
626 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
627 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
628 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
629 int usb_gadget_connect(struct usb_gadget *gadget);
630 int usb_gadget_disconnect(struct usb_gadget *gadget);
631 int usb_gadget_deactivate(struct usb_gadget *gadget);
632 int usb_gadget_activate(struct usb_gadget *gadget);
633 int usb_gadget_check_config(struct usb_gadget *gadget);
634 #else
usb_gadget_frame_number(struct usb_gadget *gadget)635 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
636 { return 0; }
usb_gadget_wakeup(struct usb_gadget *gadget)637 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
638 { return 0; }
usb_gadget_set_selfpowered(struct usb_gadget *gadget)639 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
640 { return 0; }
usb_gadget_clear_selfpowered(struct usb_gadget *gadget)641 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
642 { return 0; }
usb_gadget_vbus_connect(struct usb_gadget *gadget)643 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
644 { return 0; }
usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)645 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
646 { return 0; }
usb_gadget_vbus_disconnect(struct usb_gadget *gadget)647 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
648 { return 0; }
usb_gadget_connect(struct usb_gadget *gadget)649 static inline int usb_gadget_connect(struct usb_gadget *gadget)
650 { return 0; }
usb_gadget_disconnect(struct usb_gadget *gadget)651 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
652 { return 0; }
usb_gadget_deactivate(struct usb_gadget *gadget)653 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
654 { return 0; }
usb_gadget_activate(struct usb_gadget *gadget)655 static inline int usb_gadget_activate(struct usb_gadget *gadget)
656 { return 0; }
usb_gadget_check_config(struct usb_gadget *gadget)657 static inline int usb_gadget_check_config(struct usb_gadget *gadget)
658 { return 0; }
659 #endif /* CONFIG_USB_GADGET */
660
661 /*-------------------------------------------------------------------------*/
662
663 /**
664 * struct usb_gadget_driver - driver for usb gadget devices
665 * @function: String describing the gadget's function
666 * @max_speed: Highest speed the driver handles.
667 * @setup: Invoked for ep0 control requests that aren't handled by
668 * the hardware level driver. Most calls must be handled by
669 * the gadget driver, including descriptor and configuration
670 * management. The 16 bit members of the setup data are in
671 * USB byte order. Called in_interrupt; this may not sleep. Driver
672 * queues a response to ep0, or returns negative to stall.
673 * @disconnect: Invoked after all transfers have been stopped,
674 * when the host is disconnected. May be called in_interrupt; this
675 * may not sleep. Some devices can't detect disconnect, so this might
676 * not be called except as part of controller shutdown.
677 * @bind: the driver's bind callback
678 * @unbind: Invoked when the driver is unbound from a gadget,
679 * usually from rmmod (after a disconnect is reported).
680 * Called in a context that permits sleeping.
681 * @suspend: Invoked on USB suspend. May be called in_interrupt.
682 * @resume: Invoked on USB resume. May be called in_interrupt.
683 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
684 * and should be called in_interrupt.
685 * @driver: Driver model state for this driver.
686 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
687 * this driver will be bound to any available UDC.
688 * @pending: UDC core private data used for deferred probe of this driver.
689 * @match_existing_only: If udc is not found, return an error and don't add this
690 * gadget driver to list of pending driver
691 *
692 * Devices are disabled till a gadget driver successfully bind()s, which
693 * means the driver will handle setup() requests needed to enumerate (and
694 * meet "chapter 9" requirements) then do some useful work.
695 *
696 * If gadget->is_otg is true, the gadget driver must provide an OTG
697 * descriptor during enumeration, or else fail the bind() call. In such
698 * cases, no USB traffic may flow until both bind() returns without
699 * having called usb_gadget_disconnect(), and the USB host stack has
700 * initialized.
701 *
702 * Drivers use hardware-specific knowledge to configure the usb hardware.
703 * endpoint addressing is only one of several hardware characteristics that
704 * are in descriptors the ep0 implementation returns from setup() calls.
705 *
706 * Except for ep0 implementation, most driver code shouldn't need change to
707 * run on top of different usb controllers. It'll use endpoints set up by
708 * that ep0 implementation.
709 *
710 * The usb controller driver handles a few standard usb requests. Those
711 * include set_address, and feature flags for devices, interfaces, and
712 * endpoints (the get_status, set_feature, and clear_feature requests).
713 *
714 * Accordingly, the driver's setup() callback must always implement all
715 * get_descriptor requests, returning at least a device descriptor and
716 * a configuration descriptor. Drivers must make sure the endpoint
717 * descriptors match any hardware constraints. Some hardware also constrains
718 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
719 *
720 * The driver's setup() callback must also implement set_configuration,
721 * and should also implement set_interface, get_configuration, and
722 * get_interface. Setting a configuration (or interface) is where
723 * endpoints should be activated or (config 0) shut down.
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 struct list_head pending;
754 unsigned match_existing_only: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 * these will usually be implemented directly by the hardware-dependent
765 * usb bus interface driver, which will only support a single driver.
766 */
767
768 /**
769 * usb_gadget_probe_driver - probe a gadget driver
770 * @driver: the driver being registered
771 * Context: can sleep
772 *
773 * Call this in your gadget driver's module initialization function,
774 * to tell the underlying usb controller driver about your driver.
775 * The @bind() function will be called to bind it to a gadget before this
776 * registration call returns. It's expected that the @bind() function will
777 * be in init sections.
778 */
779 int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
780
781 /**
782 * usb_gadget_unregister_driver - unregister a gadget driver
783 * @driver:the driver being unregistered
784 * Context: can sleep
785 *
786 * Call this in your gadget driver's module cleanup function,
787 * to tell the underlying usb controller that your driver is
788 * going away. If the controller is connected to a USB host,
789 * it will first disconnect(). The driver is also requested
790 * to unbind() and clean up any device state, before this procedure
791 * finally returns. It's expected that the unbind() functions
792 * will be in exit sections, so may not be linked in some kernels.
793 */
794 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
795
796 /*-------------------------------------------------------------------------*/
797
798 /* utility to simplify dealing with string descriptors */
799
800 /**
801 * struct usb_string - wraps a C string and its USB id
802 * @id:the (nonzero) ID for this string
803 * @s:the string, in UTF-8 encoding
804 *
805 * If you're using usb_gadget_get_string(), use this to wrap a string
806 * together with its ID.
807 */
808 struct usb_string {
809 u8 id;
810 const char *s;
811 };
812
813 /**
814 * struct usb_gadget_strings - a set of USB strings in a given language
815 * @language:identifies the strings' language (0x0409 for en-us)
816 * @strings:array of strings with their ids
817 *
818 * If you're using usb_gadget_get_string(), use this to wrap all the
819 * strings for a given language.
820 */
821 struct usb_gadget_strings {
822 u16 language; /* 0x0409 for en-us */
823 struct usb_string *strings;
824 };
825
826 struct usb_gadget_string_container {
827 struct list_head list;
828 u8 *stash[];
829 };
830
831 /* put descriptor for string with that id into buf (buflen >= 256) */
832 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
833
834 /* check if the given language identifier is valid */
835 bool usb_validate_langid(u16 langid);
836
837 /*-------------------------------------------------------------------------*/
838
839 /* utility to simplify managing config descriptors */
840
841 /* write vector of descriptors into buffer */
842 int usb_descriptor_fillbuf(void *, unsigned,
843 const struct usb_descriptor_header **);
844
845 /* build config descriptor from single descriptor vector */
846 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
847 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
848
849 /* copy a NULL-terminated vector of descriptors */
850 struct usb_descriptor_header **usb_copy_descriptors(
851 struct usb_descriptor_header **);
852
853 /**
854 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
855 * @v: vector of descriptors
856 */
usb_free_descriptors(struct usb_descriptor_header **v)857 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
858 {
859 kfree(v);
860 }
861
862 struct usb_function;
863 int usb_assign_descriptors(struct usb_function *f,
864 struct usb_descriptor_header **fs,
865 struct usb_descriptor_header **hs,
866 struct usb_descriptor_header **ss,
867 struct usb_descriptor_header **ssp);
868 void usb_free_all_descriptors(struct usb_function *f);
869
870 struct usb_descriptor_header *usb_otg_descriptor_alloc(
871 struct usb_gadget *gadget);
872 int usb_otg_descriptor_init(struct usb_gadget *gadget,
873 struct usb_descriptor_header *otg_desc);
874 /*-------------------------------------------------------------------------*/
875
876 /* utility to simplify map/unmap of usb_requests to/from DMA */
877
878 #ifdef CONFIG_HAS_DMA
879 extern int usb_gadget_map_request_by_dev(struct device *dev,
880 struct usb_request *req, int is_in);
881 extern int usb_gadget_map_request(struct usb_gadget *gadget,
882 struct usb_request *req, int is_in);
883
884 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
885 struct usb_request *req, int is_in);
886 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
887 struct usb_request *req, int is_in);
888 #else /* !CONFIG_HAS_DMA */
usb_gadget_map_request_by_dev(struct device *dev, struct usb_request *req, int is_in)889 static inline int usb_gadget_map_request_by_dev(struct device *dev,
890 struct usb_request *req, int is_in) { return -ENOSYS; }
usb_gadget_map_request(struct usb_gadget *gadget, struct usb_request *req, int is_in)891 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
892 struct usb_request *req, int is_in) { return -ENOSYS; }
893
usb_gadget_unmap_request_by_dev(struct device *dev, struct usb_request *req, int is_in)894 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
895 struct usb_request *req, int is_in) { }
usb_gadget_unmap_request(struct usb_gadget *gadget, struct usb_request *req, int is_in)896 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
897 struct usb_request *req, int is_in) { }
898 #endif /* !CONFIG_HAS_DMA */
899
900 /*-------------------------------------------------------------------------*/
901
902 /* utility to set gadget state properly */
903
904 extern void usb_gadget_set_state(struct usb_gadget *gadget,
905 enum usb_device_state state);
906
907 /*-------------------------------------------------------------------------*/
908
909 /* utility to tell udc core that the bus reset occurs */
910 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
911 struct usb_gadget_driver *driver);
912
913 /*-------------------------------------------------------------------------*/
914
915 /* utility to give requests back to the gadget layer */
916
917 extern void usb_gadget_giveback_request(struct usb_ep *ep,
918 struct usb_request *req);
919
920 /*-------------------------------------------------------------------------*/
921
922 /* utility to find endpoint by name */
923
924 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
925 const char *name);
926
927 /*-------------------------------------------------------------------------*/
928
929 /* utility to check if endpoint caps match descriptor needs */
930
931 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
932 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
933 struct usb_ss_ep_comp_descriptor *ep_comp);
934
935 /*-------------------------------------------------------------------------*/
936
937 /* utility to update vbus status for udc core, it may be scheduled */
938 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
939
940 /*-------------------------------------------------------------------------*/
941
942 /* utility wrapping a simple endpoint selection policy */
943
944 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
945 struct usb_endpoint_descriptor *);
946
947
948 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
949 struct usb_endpoint_descriptor *,
950 struct usb_ss_ep_comp_descriptor *);
951
952 extern void usb_ep_autoconfig_release(struct usb_ep *);
953
954 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
955
956 #endif /* __LINUX_USB_GADGET_H */
957