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