1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * <linux/usb/gadget.h>
4 *
5 * We call the USB code inside a Linux-based peripheral device a "gadget"
6 * driver, except for the hardware-specific bus glue. One USB host can
7 * talk to many USB gadgets, but the gadgets are only able to communicate
8 * to one host.
9 *
10 *
11 * (C) Copyright 2002-2004 by David Brownell
12 * All Rights Reserved.
13 */
14
15 #ifndef __LINUX_USB_GADGET_H
16 #define __LINUX_USB_GADGET_H
17
18 #include <linux/configfs.h>
19 #include <linux/device.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/scatterlist.h>
25 #include <linux/types.h>
26 #include <linux/workqueue.h>
27 #include <linux/usb/ch9.h>
28
29 #define UDC_TRACE_STR_MAX 512
30
31 struct usb_ep;
32
33 /**
34 * struct usb_request - describes one i/o request
35 * @buf: Buffer used for data. Always provide this; some controllers
36 * only use PIO, or don't use DMA for some endpoints.
37 * @dma: DMA address corresponding to 'buf'. If you don't set this
38 * field, and the usb controller needs one, it is responsible
39 * for mapping and unmapping the buffer.
40 * @sg: a scatterlist for SG-capable controllers.
41 * @num_sgs: number of SG entries
42 * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
43 * @length: Length of that data
44 * @stream_id: The stream id, when USB3.0 bulk streams are being used
45 * @is_last: Indicates if this is the last request of a stream_id before
46 * switching to a different stream (required for DWC3 controllers).
47 * @no_interrupt: If true, hints that no completion irq is needed.
48 * Helpful sometimes with deep request queues that are handled
49 * directly by DMA controllers.
50 * @zero: If true, when writing data, makes the last packet be "short"
51 * by adding a zero length packet as needed;
52 * @short_not_ok: When reading data, makes short packets be
53 * treated as errors (queue stops advancing till cleanup).
54 * @dma_mapped: Indicates if request has been mapped to DMA (internal)
55 * @sg_was_mapped: Set if the scatterlist has been mapped before the request
56 * @complete: Function called when request completes, so this request and
57 * its buffer may be re-used. The function will always be called with
58 * interrupts disabled, and it must not sleep.
59 * Reads terminate with a short packet, or when the buffer fills,
60 * whichever comes first. When writes terminate, some data bytes
61 * will usually still be in flight (often in a hardware fifo).
62 * Errors (for reads or writes) stop the queue from advancing
63 * until the completion function returns, so that any transfers
64 * invalidated by the error may first be dequeued.
65 * @context: For use by the completion callback
66 * @list: For use by the gadget driver.
67 * @frame_number: Reports the interval number in (micro)frame in which the
68 * isochronous transfer was transmitted or received.
69 * @status: Reports completion code, zero or a negative errno.
70 * Normally, faults block the transfer queue from advancing until
71 * the completion callback returns.
72 * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
73 * or when the driver disabled the endpoint.
74 * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
75 * transfers) this may be less than the requested length. If the
76 * short_not_ok flag is set, short reads are treated as errors
77 * even when status otherwise indicates successful completion.
78 * Note that for writes (IN transfers) some data bytes may still
79 * reside in a device-side FIFO when the request is reported as
80 * complete.
81 *
82 * These are allocated/freed through the endpoint they're used with. The
83 * hardware's driver can add extra per-request data to the memory it returns,
84 * which often avoids separate memory allocations (potential failures),
85 * later when the request is queued.
86 *
87 * Request flags affect request handling, such as whether a zero length
88 * packet is written (the "zero" flag), whether a short read should be
89 * treated as an error (blocking request queue advance, the "short_not_ok"
90 * flag), or hinting that an interrupt is not required (the "no_interrupt"
91 * flag, for use with deep request queues).
92 *
93 * Bulk endpoints can use any size buffers, and can also be used for interrupt
94 * transfers. interrupt-only endpoints can be much less functional.
95 *
96 * NOTE: this is analogous to 'struct urb' on the host side, except that
97 * it's thinner and promotes more pre-allocation.
98 */
99
100 struct usb_request {
101 void *buf;
102 unsigned length;
103 dma_addr_t dma;
104
105 struct scatterlist *sg;
106 unsigned num_sgs;
107 unsigned num_mapped_sgs;
108
109 unsigned stream_id:16;
110 unsigned is_last:1;
111 unsigned no_interrupt:1;
112 unsigned zero:1;
113 unsigned short_not_ok:1;
114 unsigned dma_mapped:1;
115 unsigned sg_was_mapped:1;
116
117 void (*complete)(struct usb_ep *ep,
118 struct usb_request *req);
119 void *context;
120 struct list_head list;
121
122 unsigned frame_number; /* ISO ONLY */
123
124 int status;
125 unsigned actual;
126
127 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 endpoint.
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 *
226 * the bus controller driver lists all the general purpose endpoints in
227 * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
228 * and is accessed only in response to a driver setup() callback.
229 */
230
231 struct usb_ep {
232 void *driver_data;
233
234 const char *name;
235 const struct usb_ep_ops *ops;
236 const struct usb_endpoint_descriptor *desc;
237 const struct usb_ss_ep_comp_descriptor *comp_desc;
238 struct list_head ep_list;
239 struct usb_ep_caps caps;
240 bool claimed;
241 bool enabled;
242 unsigned mult:2;
243 unsigned maxburst:5;
244 u8 address;
245 u16 maxpacket;
246 u16 maxpacket_limit;
247 u16 max_streams;
248
249 ANDROID_KABI_RESERVE(1);
250 };
251
252 /*-------------------------------------------------------------------------*/
253
254 #if IS_ENABLED(CONFIG_USB_GADGET)
255 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
256 int usb_ep_enable(struct usb_ep *ep);
257 int usb_ep_disable(struct usb_ep *ep);
258 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
259 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
260 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
261 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
262 int usb_ep_set_halt(struct usb_ep *ep);
263 int usb_ep_clear_halt(struct usb_ep *ep);
264 int usb_ep_set_wedge(struct usb_ep *ep);
265 int usb_ep_fifo_status(struct usb_ep *ep);
266 void usb_ep_fifo_flush(struct usb_ep *ep);
267 #else
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)268 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
269 unsigned maxpacket_limit)
270 { }
usb_ep_enable(struct usb_ep * ep)271 static inline int usb_ep_enable(struct usb_ep *ep)
272 { return 0; }
usb_ep_disable(struct usb_ep * ep)273 static inline int usb_ep_disable(struct usb_ep *ep)
274 { return 0; }
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)275 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
276 gfp_t gfp_flags)
277 { return NULL; }
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)278 static inline void usb_ep_free_request(struct usb_ep *ep,
279 struct usb_request *req)
280 { }
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)281 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
282 gfp_t gfp_flags)
283 { return 0; }
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)284 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
285 { return 0; }
usb_ep_set_halt(struct usb_ep * ep)286 static inline int usb_ep_set_halt(struct usb_ep *ep)
287 { return 0; }
usb_ep_clear_halt(struct usb_ep * ep)288 static inline int usb_ep_clear_halt(struct usb_ep *ep)
289 { return 0; }
usb_ep_set_wedge(struct usb_ep * ep)290 static inline int usb_ep_set_wedge(struct usb_ep *ep)
291 { return 0; }
usb_ep_fifo_status(struct usb_ep * ep)292 static inline int usb_ep_fifo_status(struct usb_ep *ep)
293 { return 0; }
usb_ep_fifo_flush(struct usb_ep * ep)294 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
295 { }
296 #endif /* USB_GADGET */
297
298 /*-------------------------------------------------------------------------*/
299
300 struct usb_dcd_config_params {
301 __u8 bU1devExitLat; /* U1 Device exit Latency */
302 #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
303 __le16 bU2DevExitLat; /* U2 Device exit Latency */
304 #define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
305 __u8 besl_baseline; /* Recommended baseline BESL (0-15) */
306 __u8 besl_deep; /* Recommended deep BESL (0-15) */
307 #define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
308 };
309
310
311 struct usb_gadget;
312 struct usb_gadget_driver;
313 struct usb_udc;
314
315 /* the rest of the api to the controller hardware: device operations,
316 * which don't involve endpoints (or i/o).
317 */
318 struct usb_gadget_ops {
319 int (*get_frame)(struct usb_gadget *);
320 int (*wakeup)(struct usb_gadget *);
321 int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
322 int (*set_remote_wakeup)(struct usb_gadget *, int set);
323 int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
324 int (*vbus_session) (struct usb_gadget *, int is_active);
325 int (*vbus_draw) (struct usb_gadget *, unsigned mA);
326 int (*pullup) (struct usb_gadget *, int is_on);
327 int (*ioctl)(struct usb_gadget *,
328 unsigned code, unsigned long param);
329 void (*get_config_params)(struct usb_gadget *,
330 struct usb_dcd_config_params *);
331 int (*udc_start)(struct usb_gadget *,
332 struct usb_gadget_driver *);
333 int (*udc_stop)(struct usb_gadget *);
334 void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
335 void (*udc_set_ssp_rate)(struct usb_gadget *gadget,
336 enum usb_ssp_rate rate);
337 void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
338 struct usb_ep *(*match_ep)(struct usb_gadget *,
339 struct usb_endpoint_descriptor *,
340 struct usb_ss_ep_comp_descriptor *);
341 int (*check_config)(struct usb_gadget *gadget);
342
343 ANDROID_KABI_RESERVE(1);
344 ANDROID_KABI_RESERVE(2);
345 ANDROID_KABI_RESERVE(3);
346 ANDROID_KABI_RESERVE(4);
347 };
348
349 /**
350 * struct usb_gadget - represents a usb device
351 * @work: (internal use) Workqueue to be used for sysfs_notify()
352 * @udc: struct usb_udc pointer for this gadget
353 * @ops: Function pointers used to access hardware-specific operations.
354 * @ep0: Endpoint zero, used when reading or writing responses to
355 * driver setup() requests
356 * @ep_list: List of other endpoints supported by the device.
357 * @speed: Speed of current connection to USB host.
358 * @max_speed: Maximal speed the UDC can handle. UDC must support this
359 * and all slower speeds.
360 * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
361 * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
362 * can handle. The UDC must support this and all slower speeds and lower
363 * number of lanes.
364 * @state: the state we are now (attached, suspended, configured, etc)
365 * @name: Identifies the controller hardware type. Used in diagnostics
366 * and sometimes configuration.
367 * @dev: Driver model state for this abstract device.
368 * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
369 * @out_epnum: last used out ep number
370 * @in_epnum: last used in ep number
371 * @mA: last set mA value
372 * @otg_caps: OTG capabilities of this gadget.
373 * @sg_supported: true if we can handle scatter-gather
374 * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
375 * gadget driver must provide a USB OTG descriptor.
376 * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
377 * is in the Mini-AB jack, and HNP has been used to switch roles
378 * so that the "A" device currently acts as A-Peripheral, not A-Host.
379 * @a_hnp_support: OTG device feature flag, indicating that the A-Host
380 * supports HNP at this port.
381 * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
382 * only supports HNP on a different root port.
383 * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
384 * enabled HNP support.
385 * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
386 * in peripheral mode can support HNP polling.
387 * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
388 * or B-Peripheral wants to take host role.
389 * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
390 * MaxPacketSize.
391 * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
392 * @quirk_stall_not_supp: UDC controller doesn't support stalling.
393 * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
394 * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
395 * u_ether.c to improve performance.
396 * @is_selfpowered: if the gadget is self-powered.
397 * @deactivated: True if gadget is deactivated - in deactivated state it cannot
398 * be connected.
399 * @connected: True if gadget is connected.
400 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
401 * indicates that it supports LPM as per the LPM ECN & errata.
402 * @wakeup_capable: True if gadget is capable of sending remote wakeup.
403 * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
404 * @irq: the interrupt number for device controller.
405 * @id_number: a unique ID number for ensuring that gadget names are distinct
406 *
407 * Gadgets have a mostly-portable "gadget driver" implementing device
408 * functions, handling all usb configurations and interfaces. Gadget
409 * drivers talk to hardware-specific code indirectly, through ops vectors.
410 * That insulates the gadget driver from hardware details, and packages
411 * the hardware endpoints through generic i/o queues. The "usb_gadget"
412 * and "usb_ep" interfaces provide that insulation from the hardware.
413 *
414 * Except for the driver data, all fields in this structure are
415 * read-only to the gadget driver. That driver data is part of the
416 * "driver model" infrastructure in 2.6 (and later) kernels, and for
417 * earlier systems is grouped in a similar structure that's not known
418 * to the rest of the kernel.
419 *
420 * Values of the three OTG device feature flags are updated before the
421 * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
422 * driver suspend() calls. They are valid only when is_otg, and when the
423 * device is acting as a B-Peripheral (so is_a_peripheral is false).
424 */
425 struct usb_gadget {
426 struct work_struct work;
427 struct usb_udc *udc;
428 /* readonly to gadget driver */
429 const struct usb_gadget_ops *ops;
430 struct usb_ep *ep0;
431 struct list_head ep_list; /* of usb_ep */
432 enum usb_device_speed speed;
433 enum usb_device_speed max_speed;
434
435 /* USB SuperSpeed Plus only */
436 enum usb_ssp_rate ssp_rate;
437 enum usb_ssp_rate max_ssp_rate;
438
439 enum usb_device_state state;
440 const char *name;
441 struct device dev;
442 unsigned isoch_delay;
443 unsigned out_epnum;
444 unsigned in_epnum;
445 unsigned mA;
446 struct usb_otg_caps *otg_caps;
447
448 unsigned sg_supported:1;
449 unsigned is_otg:1;
450 unsigned is_a_peripheral:1;
451 unsigned b_hnp_enable:1;
452 unsigned a_hnp_support:1;
453 unsigned a_alt_hnp_support:1;
454 unsigned hnp_polling_support:1;
455 unsigned host_request_flag:1;
456 unsigned quirk_ep_out_aligned_size:1;
457 unsigned quirk_altset_not_supp:1;
458 unsigned quirk_stall_not_supp:1;
459 unsigned quirk_zlp_not_supp:1;
460 unsigned quirk_avoids_skb_reserve:1;
461 unsigned is_selfpowered:1;
462 unsigned deactivated:1;
463 unsigned connected:1;
464 unsigned lpm_capable:1;
465 unsigned wakeup_capable:1;
466 unsigned wakeup_armed:1;
467 int irq;
468 int id_number;
469 };
470 #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
471
472 /* Interface to the device model */
set_gadget_data(struct usb_gadget * gadget,void * data)473 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
474 { dev_set_drvdata(&gadget->dev, data); }
get_gadget_data(struct usb_gadget * gadget)475 static inline void *get_gadget_data(struct usb_gadget *gadget)
476 { return dev_get_drvdata(&gadget->dev); }
dev_to_usb_gadget(struct device * dev)477 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
478 {
479 return container_of(dev, struct usb_gadget, dev);
480 }
usb_get_gadget(struct usb_gadget * gadget)481 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
482 {
483 get_device(&gadget->dev);
484 return gadget;
485 }
usb_put_gadget(struct usb_gadget * gadget)486 static inline void usb_put_gadget(struct usb_gadget *gadget)
487 {
488 put_device(&gadget->dev);
489 }
490 extern void usb_initialize_gadget(struct device *parent,
491 struct usb_gadget *gadget, void (*release)(struct device *dev));
492 extern int usb_add_gadget(struct usb_gadget *gadget);
493 extern void usb_del_gadget(struct usb_gadget *gadget);
494
495 /* Legacy device-model interface */
496 extern int usb_add_gadget_udc_release(struct device *parent,
497 struct usb_gadget *gadget, void (*release)(struct device *dev));
498 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
499 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
500 extern char *usb_get_gadget_udc_name(void);
501
502 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
503 #define gadget_for_each_ep(tmp, gadget) \
504 list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
505
506 /**
507 * usb_ep_align - returns @len aligned to ep's maxpacketsize.
508 * @ep: the endpoint whose maxpacketsize is used to align @len
509 * @len: buffer size's length to align to @ep's maxpacketsize
510 *
511 * This helper is used to align buffer's size to an ep's maxpacketsize.
512 */
usb_ep_align(struct usb_ep * ep,size_t len)513 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
514 {
515 int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc);
516
517 return round_up(len, max_packet_size);
518 }
519
520 /**
521 * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
522 * requires quirk_ep_out_aligned_size, otherwise returns len.
523 * @g: controller to check for quirk
524 * @ep: the endpoint whose maxpacketsize is used to align @len
525 * @len: buffer size's length to align to @ep's maxpacketsize
526 *
527 * This helper is used in case it's required for any reason to check and maybe
528 * align buffer's size to an ep's maxpacketsize.
529 */
530 static inline size_t
usb_ep_align_maybe(struct usb_gadget * g,struct usb_ep * ep,size_t len)531 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
532 {
533 return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
534 }
535
536 /**
537 * gadget_is_altset_supported - return true iff the hardware supports
538 * altsettings
539 * @g: controller to check for quirk
540 */
gadget_is_altset_supported(struct usb_gadget * g)541 static inline int gadget_is_altset_supported(struct usb_gadget *g)
542 {
543 return !g->quirk_altset_not_supp;
544 }
545
546 /**
547 * gadget_is_stall_supported - return true iff the hardware supports stalling
548 * @g: controller to check for quirk
549 */
gadget_is_stall_supported(struct usb_gadget * g)550 static inline int gadget_is_stall_supported(struct usb_gadget *g)
551 {
552 return !g->quirk_stall_not_supp;
553 }
554
555 /**
556 * gadget_is_zlp_supported - return true iff the hardware supports zlp
557 * @g: controller to check for quirk
558 */
gadget_is_zlp_supported(struct usb_gadget * g)559 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
560 {
561 return !g->quirk_zlp_not_supp;
562 }
563
564 /**
565 * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
566 * skb_reserve to improve performance.
567 * @g: controller to check for quirk
568 */
gadget_avoids_skb_reserve(struct usb_gadget * g)569 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
570 {
571 return g->quirk_avoids_skb_reserve;
572 }
573
574 /**
575 * gadget_is_dualspeed - return true iff the hardware handles high speed
576 * @g: controller that might support both high and full speeds
577 */
gadget_is_dualspeed(struct usb_gadget * g)578 static inline int gadget_is_dualspeed(struct usb_gadget *g)
579 {
580 return g->max_speed >= USB_SPEED_HIGH;
581 }
582
583 /**
584 * gadget_is_superspeed() - return true if the hardware handles superspeed
585 * @g: controller that might support superspeed
586 */
gadget_is_superspeed(struct usb_gadget * g)587 static inline int gadget_is_superspeed(struct usb_gadget *g)
588 {
589 return g->max_speed >= USB_SPEED_SUPER;
590 }
591
592 /**
593 * gadget_is_superspeed_plus() - return true if the hardware handles
594 * superspeed plus
595 * @g: controller that might support superspeed plus
596 */
gadget_is_superspeed_plus(struct usb_gadget * g)597 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
598 {
599 return g->max_speed >= USB_SPEED_SUPER_PLUS;
600 }
601
602 /**
603 * gadget_is_otg - return true iff the hardware is OTG-ready
604 * @g: controller that might have a Mini-AB connector
605 *
606 * This is a runtime test, since kernels with a USB-OTG stack sometimes
607 * run on boards which only have a Mini-B (or Mini-A) connector.
608 */
gadget_is_otg(struct usb_gadget * g)609 static inline int gadget_is_otg(struct usb_gadget *g)
610 {
611 #ifdef CONFIG_USB_OTG
612 return g->is_otg;
613 #else
614 return 0;
615 #endif
616 }
617
618 /*-------------------------------------------------------------------------*/
619
620 #if IS_ENABLED(CONFIG_USB_GADGET)
621 int usb_gadget_frame_number(struct usb_gadget *gadget);
622 int usb_gadget_wakeup(struct usb_gadget *gadget);
623 int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
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_remote_wakeup(struct usb_gadget * gadget,int set)639 static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
640 { return 0; }
usb_gadget_set_selfpowered(struct usb_gadget * gadget)641 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
642 { return 0; }
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)643 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
644 { return 0; }
usb_gadget_vbus_connect(struct usb_gadget * gadget)645 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
646 { return 0; }
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)647 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
648 { return 0; }
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)649 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
650 { return 0; }
usb_gadget_connect(struct usb_gadget * gadget)651 static inline int usb_gadget_connect(struct usb_gadget *gadget)
652 { return 0; }
usb_gadget_disconnect(struct usb_gadget * gadget)653 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
654 { return 0; }
usb_gadget_deactivate(struct usb_gadget * gadget)655 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
656 { return 0; }
usb_gadget_activate(struct usb_gadget * gadget)657 static inline int usb_gadget_activate(struct usb_gadget *gadget)
658 { return 0; }
usb_gadget_check_config(struct usb_gadget * gadget)659 static inline int usb_gadget_check_config(struct usb_gadget *gadget)
660 { return 0; }
661 #endif /* CONFIG_USB_GADGET */
662
663 /*-------------------------------------------------------------------------*/
664
665 /**
666 * struct usb_gadget_driver - driver for usb gadget devices
667 * @function: String describing the gadget's function
668 * @max_speed: Highest speed the driver handles.
669 * @setup: Invoked for ep0 control requests that aren't handled by
670 * the hardware level driver. Most calls must be handled by
671 * the gadget driver, including descriptor and configuration
672 * management. The 16 bit members of the setup data are in
673 * USB byte order. Called in_interrupt; this may not sleep. Driver
674 * queues a response to ep0, or returns negative to stall.
675 * @disconnect: Invoked after all transfers have been stopped,
676 * when the host is disconnected. May be called in_interrupt; this
677 * may not sleep. Some devices can't detect disconnect, so this might
678 * not be called except as part of controller shutdown.
679 * @bind: the driver's bind callback
680 * @unbind: Invoked when the driver is unbound from a gadget,
681 * usually from rmmod (after a disconnect is reported).
682 * Called in a context that permits sleeping.
683 * @suspend: Invoked on USB suspend. May be called in_interrupt.
684 * @resume: Invoked on USB resume. May be called in_interrupt.
685 * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
686 * and should be called in_interrupt.
687 * @driver: Driver model state for this driver.
688 * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
689 * this driver will be bound to any available UDC.
690 * @match_existing_only: If udc is not found, return an error and fail
691 * the driver registration
692 * @is_bound: Allow a driver to be bound to only one gadget
693 *
694 * Devices are disabled till a gadget driver successfully bind()s, which
695 * means the driver will handle setup() requests needed to enumerate (and
696 * meet "chapter 9" requirements) then do some useful work.
697 *
698 * If gadget->is_otg is true, the gadget driver must provide an OTG
699 * descriptor during enumeration, or else fail the bind() call. In such
700 * cases, no USB traffic may flow until both bind() returns without
701 * having called usb_gadget_disconnect(), and the USB host stack has
702 * initialized.
703 *
704 * Drivers use hardware-specific knowledge to configure the usb hardware.
705 * endpoint addressing is only one of several hardware characteristics that
706 * are in descriptors the ep0 implementation returns from setup() calls.
707 *
708 * Except for ep0 implementation, most driver code shouldn't need change to
709 * run on top of different usb controllers. It'll use endpoints set up by
710 * that ep0 implementation.
711 *
712 * The usb controller driver handles a few standard usb requests. Those
713 * include set_address, and feature flags for devices, interfaces, and
714 * endpoints (the get_status, set_feature, and clear_feature requests).
715 *
716 * Accordingly, the driver's setup() callback must always implement all
717 * get_descriptor requests, returning at least a device descriptor and
718 * a configuration descriptor. Drivers must make sure the endpoint
719 * descriptors match any hardware constraints. Some hardware also constrains
720 * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
721 *
722 * The driver's setup() callback must also implement set_configuration,
723 * and should also implement set_interface, get_configuration, and
724 * get_interface. Setting a configuration (or interface) is where
725 * endpoints should be activated or (config 0) shut down.
726 *
727 * The gadget driver's setup() callback does not have to queue a response to
728 * ep0 within the setup() call, the driver can do it after setup() returns.
729 * The UDC driver must wait until such a response is queued before proceeding
730 * with the data/status stages of the control transfer.
731 *
732 * NOTE: Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS
733 * being returned from the setup() callback, which is a bug. See the comment
734 * next to USB_GADGET_DELAYED_STATUS for details.
735 *
736 * (Note that only the default control endpoint is supported. Neither
737 * hosts nor devices generally support control traffic except to ep0.)
738 *
739 * Most devices will ignore USB suspend/resume operations, and so will
740 * not provide those callbacks. However, some may need to change modes
741 * when the host is not longer directing those activities. For example,
742 * local controls (buttons, dials, etc) may need to be re-enabled since
743 * the (remote) host can't do that any longer; or an error state might
744 * be cleared, to make the device behave identically whether or not
745 * power is maintained.
746 */
747 struct usb_gadget_driver {
748 char *function;
749 enum usb_device_speed max_speed;
750 int (*bind)(struct usb_gadget *gadget,
751 struct usb_gadget_driver *driver);
752 void (*unbind)(struct usb_gadget *);
753 int (*setup)(struct usb_gadget *,
754 const struct usb_ctrlrequest *);
755 void (*disconnect)(struct usb_gadget *);
756 void (*suspend)(struct usb_gadget *);
757 void (*resume)(struct usb_gadget *);
758 void (*reset)(struct usb_gadget *);
759
760 /* FIXME support safe rmmod */
761 struct device_driver driver;
762
763 char *udc_name;
764 unsigned match_existing_only:1;
765 bool is_bound:1;
766 };
767
768
769
770 /*-------------------------------------------------------------------------*/
771
772 /* driver modules register and unregister, as usual.
773 * these calls must be made in a context that can sleep.
774 *
775 * A gadget driver can be bound to only one gadget at a time.
776 */
777
778 /**
779 * usb_gadget_register_driver_owner - register a gadget driver
780 * @driver: the driver being registered
781 * @owner: the driver module
782 * @mod_name: the driver module's build name
783 * Context: can sleep
784 *
785 * Call this in your gadget driver's module initialization function,
786 * to tell the underlying UDC controller driver about your driver.
787 * The @bind() function will be called to bind it to a gadget before this
788 * registration call returns. It's expected that the @bind() function will
789 * be in init sections.
790 *
791 * Use the macro defined below instead of calling this directly.
792 */
793 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
794 struct module *owner, const char *mod_name);
795
796 /* use a define to avoid include chaining to get THIS_MODULE & friends */
797 #define usb_gadget_register_driver(driver) \
798 usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME)
799
800 /**
801 * usb_gadget_unregister_driver - unregister a gadget driver
802 * @driver:the driver being unregistered
803 * Context: can sleep
804 *
805 * Call this in your gadget driver's module cleanup function,
806 * to tell the underlying usb controller that your driver is
807 * going away. If the controller is connected to a USB host,
808 * it will first disconnect(). The driver is also requested
809 * to unbind() and clean up any device state, before this procedure
810 * finally returns. It's expected that the unbind() functions
811 * will be in exit sections, so may not be linked in some kernels.
812 */
813 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
814
815 /*-------------------------------------------------------------------------*/
816
817 /* utility to simplify dealing with string descriptors */
818
819 /**
820 * struct usb_string - wraps a C string and its USB id
821 * @id:the (nonzero) ID for this string
822 * @s:the string, in UTF-8 encoding
823 *
824 * If you're using usb_gadget_get_string(), use this to wrap a string
825 * together with its ID.
826 */
827 struct usb_string {
828 u8 id;
829 const char *s;
830 };
831
832 /**
833 * struct usb_gadget_strings - a set of USB strings in a given language
834 * @language:identifies the strings' language (0x0409 for en-us)
835 * @strings:array of strings with their ids
836 *
837 * If you're using usb_gadget_get_string(), use this to wrap all the
838 * strings for a given language.
839 */
840 struct usb_gadget_strings {
841 u16 language; /* 0x0409 for en-us */
842 struct usb_string *strings;
843 };
844
845 struct usb_gadget_string_container {
846 struct list_head list;
847 u8 *stash[];
848 };
849
850 /* put descriptor for string with that id into buf (buflen >= 256) */
851 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
852
853 /* check if the given language identifier is valid */
854 bool usb_validate_langid(u16 langid);
855
856 struct gadget_string {
857 struct config_item item;
858 struct list_head list;
859 char string[USB_MAX_STRING_LEN];
860 struct usb_string usb_string;
861 };
862
863 #define to_gadget_string(str_item)\
864 container_of(str_item, struct gadget_string, item)
865
866 /*-------------------------------------------------------------------------*/
867
868 /* utility to simplify managing config descriptors */
869
870 /* write vector of descriptors into buffer */
871 int usb_descriptor_fillbuf(void *, unsigned,
872 const struct usb_descriptor_header **);
873
874 /* build config descriptor from single descriptor vector */
875 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
876 void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
877
878 /* copy a NULL-terminated vector of descriptors */
879 struct usb_descriptor_header **usb_copy_descriptors(
880 struct usb_descriptor_header **);
881
882 /**
883 * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
884 * @v: vector of descriptors
885 */
usb_free_descriptors(struct usb_descriptor_header ** v)886 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
887 {
888 kfree(v);
889 }
890
891 struct usb_function;
892 int usb_assign_descriptors(struct usb_function *f,
893 struct usb_descriptor_header **fs,
894 struct usb_descriptor_header **hs,
895 struct usb_descriptor_header **ss,
896 struct usb_descriptor_header **ssp);
897 void usb_free_all_descriptors(struct usb_function *f);
898
899 struct usb_descriptor_header *usb_otg_descriptor_alloc(
900 struct usb_gadget *gadget);
901 int usb_otg_descriptor_init(struct usb_gadget *gadget,
902 struct usb_descriptor_header *otg_desc);
903 /*-------------------------------------------------------------------------*/
904
905 /* utility to simplify map/unmap of usb_requests to/from DMA */
906
907 #ifdef CONFIG_HAS_DMA
908 extern int usb_gadget_map_request_by_dev(struct device *dev,
909 struct usb_request *req, int is_in);
910 extern int usb_gadget_map_request(struct usb_gadget *gadget,
911 struct usb_request *req, int is_in);
912
913 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
914 struct usb_request *req, int is_in);
915 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
916 struct usb_request *req, int is_in);
917 #else /* !CONFIG_HAS_DMA */
usb_gadget_map_request_by_dev(struct device * dev,struct usb_request * req,int is_in)918 static inline int usb_gadget_map_request_by_dev(struct device *dev,
919 struct usb_request *req, int is_in) { return -ENOSYS; }
usb_gadget_map_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)920 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
921 struct usb_request *req, int is_in) { return -ENOSYS; }
922
usb_gadget_unmap_request_by_dev(struct device * dev,struct usb_request * req,int is_in)923 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
924 struct usb_request *req, int is_in) { }
usb_gadget_unmap_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)925 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
926 struct usb_request *req, int is_in) { }
927 #endif /* !CONFIG_HAS_DMA */
928
929 /*-------------------------------------------------------------------------*/
930
931 /* utility to set gadget state properly */
932
933 extern void usb_gadget_set_state(struct usb_gadget *gadget,
934 enum usb_device_state state);
935
936 /*-------------------------------------------------------------------------*/
937
938 /* utility to tell udc core that the bus reset occurs */
939 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
940 struct usb_gadget_driver *driver);
941
942 /*-------------------------------------------------------------------------*/
943
944 /* utility to give requests back to the gadget layer */
945
946 extern void usb_gadget_giveback_request(struct usb_ep *ep,
947 struct usb_request *req);
948
949 /*-------------------------------------------------------------------------*/
950
951 /* utility to find endpoint by name */
952
953 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
954 const char *name);
955
956 /*-------------------------------------------------------------------------*/
957
958 /* utility to check if endpoint caps match descriptor needs */
959
960 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
961 struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
962 struct usb_ss_ep_comp_descriptor *ep_comp);
963
964 /*-------------------------------------------------------------------------*/
965
966 /* utility to update vbus status for udc core, it may be scheduled */
967 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
968
969 /*-------------------------------------------------------------------------*/
970
971 /* utility wrapping a simple endpoint selection policy */
972
973 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
974 struct usb_endpoint_descriptor *);
975
976
977 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
978 struct usb_endpoint_descriptor *,
979 struct usb_ss_ep_comp_descriptor *);
980
981 extern void usb_ep_autoconfig_release(struct usb_ep *);
982
983 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
984
985 #endif /* __LINUX_USB_GADGET_H */
986