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  * @complete: Function called when request completes, so this request and
56  *	its buffer may be re-used.  The function will always be called with
57  *	interrupts disabled, and it must not sleep.
58  *	Reads terminate with a short packet, or when the buffer fills,
59  *	whichever comes first.  When writes terminate, some data bytes
60  *	will usually still be in flight (often in a hardware fifo).
61  *	Errors (for reads or writes) stop the queue from advancing
62  *	until the completion function returns, so that any transfers
63  *	invalidated by the error may first be dequeued.
64  * @context: For use by the completion callback
65  * @list: For use by the gadget driver.
66  * @frame_number: Reports the interval number in (micro)frame in which the
67  *	isochronous transfer was transmitted or received.
68  * @status: Reports completion code, zero or a negative errno.
69  *	Normally, faults block the transfer queue from advancing until
70  *	the completion callback returns.
71  *	Code "-ESHUTDOWN" indicates completion caused by device disconnect,
72  *	or when the driver disabled the endpoint.
73  * @actual: Reports bytes transferred to/from the buffer.  For reads (OUT
74  *	transfers) this may be less than the requested length.  If the
75  *	short_not_ok flag is set, short reads are treated as errors
76  *	even when status otherwise indicates successful completion.
77  *	Note that for writes (IN transfers) some data bytes may still
78  *	reside in a device-side FIFO when the request is reported as
79  *	complete.
80  *
81  * These are allocated/freed through the endpoint they're used with.  The
82  * hardware's driver can add extra per-request data to the memory it returns,
83  * which often avoids separate memory allocations (potential failures),
84  * later when the request is queued.
85  *
86  * Request flags affect request handling, such as whether a zero length
87  * packet is written (the "zero" flag), whether a short read should be
88  * treated as an error (blocking request queue advance, the "short_not_ok"
89  * flag), or hinting that an interrupt is not required (the "no_interrupt"
90  * flag, for use with deep request queues).
91  *
92  * Bulk endpoints can use any size buffers, and can also be used for interrupt
93  * transfers. interrupt-only endpoints can be much less functional.
94  *
95  * NOTE:  this is analogous to 'struct urb' on the host side, except that
96  * it's thinner and promotes more pre-allocation.
97  */
98 
99 struct usb_request {
100 	void			*buf;
101 	unsigned		length;
102 	dma_addr_t		dma;
103 
104 	struct scatterlist	*sg;
105 	unsigned		num_sgs;
106 	unsigned		num_mapped_sgs;
107 
108 	unsigned		stream_id:16;
109 	unsigned		is_last:1;
110 	unsigned		no_interrupt:1;
111 	unsigned		zero:1;
112 	unsigned		short_not_ok:1;
113 	unsigned		dma_mapped:1;
114 
115 	void			(*complete)(struct usb_ep *ep,
116 					struct usb_request *req);
117 	void			*context;
118 	struct list_head	list;
119 
120 	unsigned		frame_number;		/* ISO ONLY */
121 
122 	int			status;
123 	unsigned		actual;
124 };
125 
126 /*-------------------------------------------------------------------------*/
127 
128 /* endpoint-specific parts of the api to the usb controller hardware.
129  * unlike the urb model, (de)multiplexing layers are not required.
130  * (so this api could slash overhead if used on the host side...)
131  *
132  * note that device side usb controllers commonly differ in how many
133  * endpoints they support, as well as their capabilities.
134  */
135 struct usb_ep_ops {
136 	int (*enable) (struct usb_ep *ep,
137 		const struct usb_endpoint_descriptor *desc);
138 	int (*disable) (struct usb_ep *ep);
139 	void (*dispose) (struct usb_ep *ep);
140 
141 	struct usb_request *(*alloc_request) (struct usb_ep *ep,
142 		gfp_t gfp_flags);
143 	void (*free_request) (struct usb_ep *ep, struct usb_request *req);
144 
145 	int (*queue) (struct usb_ep *ep, struct usb_request *req,
146 		gfp_t gfp_flags);
147 	int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
148 
149 	int (*set_halt) (struct usb_ep *ep, int value);
150 	int (*set_wedge) (struct usb_ep *ep);
151 
152 	int (*fifo_status) (struct usb_ep *ep);
153 	void (*fifo_flush) (struct usb_ep *ep);
154 };
155 
156 /**
157  * struct usb_ep_caps - endpoint capabilities description
158  * @type_control:Endpoint supports control type (reserved for ep0).
159  * @type_iso:Endpoint supports isochronous transfers.
160  * @type_bulk:Endpoint supports bulk transfers.
161  * @type_int:Endpoint supports interrupt transfers.
162  * @dir_in:Endpoint supports IN direction.
163  * @dir_out:Endpoint supports OUT direction.
164  */
165 struct usb_ep_caps {
166 	unsigned type_control:1;
167 	unsigned type_iso:1;
168 	unsigned type_bulk:1;
169 	unsigned type_int:1;
170 	unsigned dir_in:1;
171 	unsigned dir_out:1;
172 };
173 
174 #define USB_EP_CAPS_TYPE_CONTROL     0x01
175 #define USB_EP_CAPS_TYPE_ISO         0x02
176 #define USB_EP_CAPS_TYPE_BULK        0x04
177 #define USB_EP_CAPS_TYPE_INT         0x08
178 #define USB_EP_CAPS_TYPE_ALL \
179 	(USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
180 #define USB_EP_CAPS_DIR_IN           0x01
181 #define USB_EP_CAPS_DIR_OUT          0x02
182 #define USB_EP_CAPS_DIR_ALL  (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
183 
184 #define USB_EP_CAPS(_type, _dir) \
185 	{ \
186 		.type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
187 		.type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
188 		.type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
189 		.type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
190 		.dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
191 		.dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
192 	}
193 
194 /**
195  * struct usb_ep - device side representation of USB endpoint
196  * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
197  * @ops: Function pointers used to access hardware-specific operations.
198  * @ep_list:the gadget's ep_list holds all of its endpoints
199  * @caps:The structure describing types and directions supported by endpoint.
200  * @enabled: The current endpoint enabled/disabled state.
201  * @claimed: True if this endpoint is claimed by a function.
202  * @maxpacket:The maximum packet size used on this endpoint.  The initial
203  *	value can sometimes be reduced (hardware allowing), according to
204  *	the endpoint descriptor used to configure the endpoint.
205  * @maxpacket_limit:The maximum packet size value which can be handled by this
206  *	endpoint. It's set once by UDC driver when endpoint is initialized, and
207  *	should not be changed. Should not be confused with maxpacket.
208  * @max_streams: The maximum number of streams supported
209  *	by this EP (0 - 16, actual number is 2^n)
210  * @mult: multiplier, 'mult' value for SS Isoc EPs
211  * @maxburst: the maximum number of bursts supported by this EP (for usb3)
212  * @driver_data:for use by the gadget driver.
213  * @address: used to identify the endpoint when finding descriptor that
214  *	matches connection speed
215  * @desc: endpoint descriptor.  This pointer is set before the endpoint is
216  *	enabled and remains valid until the endpoint is disabled.
217  * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
218  *	descriptor that is used to configure the endpoint
219  *
220  * the bus controller driver lists all the general purpose endpoints in
221  * gadget->ep_list.  the control endpoint (gadget->ep0) is not in that list,
222  * and is accessed only in response to a driver setup() callback.
223  */
224 
225 struct usb_ep {
226 	void			*driver_data;
227 
228 	const char		*name;
229 	const struct usb_ep_ops	*ops;
230 	struct list_head	ep_list;
231 	struct usb_ep_caps	caps;
232 	bool			claimed;
233 	bool			enabled;
234 	unsigned		maxpacket:16;
235 	unsigned		maxpacket_limit:16;
236 	unsigned		max_streams:16;
237 	unsigned		mult:2;
238 	unsigned		maxburst:5;
239 	u8			address;
240 	const struct usb_endpoint_descriptor	*desc;
241 	const struct usb_ss_ep_comp_descriptor	*comp_desc;
242 };
243 
244 /*-------------------------------------------------------------------------*/
245 
246 #if IS_ENABLED(CONFIG_USB_GADGET)
247 void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
248 int usb_ep_enable(struct usb_ep *ep);
249 int usb_ep_disable(struct usb_ep *ep);
250 struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
251 void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
252 int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
253 int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
254 int usb_ep_set_halt(struct usb_ep *ep);
255 int usb_ep_clear_halt(struct usb_ep *ep);
256 int usb_ep_set_wedge(struct usb_ep *ep);
257 int usb_ep_fifo_status(struct usb_ep *ep);
258 void usb_ep_fifo_flush(struct usb_ep *ep);
259 #else
usb_ep_set_maxpacket_limit(struct usb_ep * ep,unsigned maxpacket_limit)260 static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
261 		unsigned maxpacket_limit)
262 { }
usb_ep_enable(struct usb_ep * ep)263 static inline int usb_ep_enable(struct usb_ep *ep)
264 { return 0; }
usb_ep_disable(struct usb_ep * ep)265 static inline int usb_ep_disable(struct usb_ep *ep)
266 { return 0; }
usb_ep_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)267 static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
268 		gfp_t gfp_flags)
269 { return NULL; }
usb_ep_free_request(struct usb_ep * ep,struct usb_request * req)270 static inline void usb_ep_free_request(struct usb_ep *ep,
271 		struct usb_request *req)
272 { }
usb_ep_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)273 static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
274 		gfp_t gfp_flags)
275 { return 0; }
usb_ep_dequeue(struct usb_ep * ep,struct usb_request * req)276 static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
277 { return 0; }
usb_ep_set_halt(struct usb_ep * ep)278 static inline int usb_ep_set_halt(struct usb_ep *ep)
279 { return 0; }
usb_ep_clear_halt(struct usb_ep * ep)280 static inline int usb_ep_clear_halt(struct usb_ep *ep)
281 { return 0; }
usb_ep_set_wedge(struct usb_ep * ep)282 static inline int usb_ep_set_wedge(struct usb_ep *ep)
283 { return 0; }
usb_ep_fifo_status(struct usb_ep * ep)284 static inline int usb_ep_fifo_status(struct usb_ep *ep)
285 { return 0; }
usb_ep_fifo_flush(struct usb_ep * ep)286 static inline void usb_ep_fifo_flush(struct usb_ep *ep)
287 { }
288 #endif /* USB_GADGET */
289 
290 /*-------------------------------------------------------------------------*/
291 
292 struct usb_dcd_config_params {
293 	__u8  bU1devExitLat;	/* U1 Device exit Latency */
294 #define USB_DEFAULT_U1_DEV_EXIT_LAT	0x01	/* Less then 1 microsec */
295 	__le16 bU2DevExitLat;	/* U2 Device exit Latency */
296 #define USB_DEFAULT_U2_DEV_EXIT_LAT	0x1F4	/* Less then 500 microsec */
297 	__u8 besl_baseline;	/* Recommended baseline BESL (0-15) */
298 	__u8 besl_deep;		/* Recommended deep BESL (0-15) */
299 #define USB_DEFAULT_BESL_UNSPECIFIED	0xFF	/* No recommended value */
300 };
301 
302 
303 struct usb_gadget;
304 struct usb_gadget_driver;
305 struct usb_udc;
306 
307 /* the rest of the api to the controller hardware: device operations,
308  * which don't involve endpoints (or i/o).
309  */
310 struct usb_gadget_ops {
311 	int	(*get_frame)(struct usb_gadget *);
312 	int	(*wakeup)(struct usb_gadget *);
313 	int	(*func_wakeup)(struct usb_gadget *gadget, int intf_id);
314 	int	(*set_remote_wakeup)(struct usb_gadget *, int set);
315 	int	(*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
316 	int	(*vbus_session) (struct usb_gadget *, int is_active);
317 	int	(*vbus_draw) (struct usb_gadget *, unsigned mA);
318 	int	(*pullup) (struct usb_gadget *, int is_on);
319 	int	(*ioctl)(struct usb_gadget *,
320 				unsigned code, unsigned long param);
321 	void	(*get_config_params)(struct usb_gadget *,
322 				     struct usb_dcd_config_params *);
323 	int	(*udc_start)(struct usb_gadget *,
324 			struct usb_gadget_driver *);
325 	int	(*udc_stop)(struct usb_gadget *);
326 	void	(*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
327 	void	(*udc_set_ssp_rate)(struct usb_gadget *gadget,
328 			enum usb_ssp_rate rate);
329 	void	(*udc_async_callbacks)(struct usb_gadget *gadget, bool enable);
330 	struct usb_ep *(*match_ep)(struct usb_gadget *,
331 			struct usb_endpoint_descriptor *,
332 			struct usb_ss_ep_comp_descriptor *);
333 	int	(*check_config)(struct usb_gadget *gadget);
334 };
335 
336 /**
337  * struct usb_gadget - represents a usb device
338  * @work: (internal use) Workqueue to be used for sysfs_notify()
339  * @udc: struct usb_udc pointer for this gadget
340  * @ops: Function pointers used to access hardware-specific operations.
341  * @ep0: Endpoint zero, used when reading or writing responses to
342  *	driver setup() requests
343  * @ep_list: List of other endpoints supported by the device.
344  * @speed: Speed of current connection to USB host.
345  * @max_speed: Maximal speed the UDC can handle.  UDC must support this
346  *      and all slower speeds.
347  * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count.
348  * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC
349  *	can handle. The UDC must support this and all slower speeds and lower
350  *	number of lanes.
351  * @state: the state we are now (attached, suspended, configured, etc)
352  * @name: Identifies the controller hardware type.  Used in diagnostics
353  *	and sometimes configuration.
354  * @dev: Driver model state for this abstract device.
355  * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
356  * @out_epnum: last used out ep number
357  * @in_epnum: last used in ep number
358  * @mA: last set mA value
359  * @otg_caps: OTG capabilities of this gadget.
360  * @sg_supported: true if we can handle scatter-gather
361  * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
362  *	gadget driver must provide a USB OTG descriptor.
363  * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
364  *	is in the Mini-AB jack, and HNP has been used to switch roles
365  *	so that the "A" device currently acts as A-Peripheral, not A-Host.
366  * @a_hnp_support: OTG device feature flag, indicating that the A-Host
367  *	supports HNP at this port.
368  * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
369  *	only supports HNP on a different root port.
370  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
371  *	enabled HNP support.
372  * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
373  *	in peripheral mode can support HNP polling.
374  * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
375  *	or B-Peripheral wants to take host role.
376  * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
377  *	MaxPacketSize.
378  * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
379  * @quirk_stall_not_supp: UDC controller doesn't support stalling.
380  * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
381  * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
382  *	u_ether.c to improve performance.
383  * @is_selfpowered: if the gadget is self-powered.
384  * @deactivated: True if gadget is deactivated - in deactivated state it cannot
385  *	be connected.
386  * @connected: True if gadget is connected.
387  * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
388  *	indicates that it supports LPM as per the LPM ECN & errata.
389  * @wakeup_capable: True if gadget is capable of sending remote wakeup.
390  * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
391  * @irq: the interrupt number for device controller.
392  * @id_number: a unique ID number for ensuring that gadget names are distinct
393  *
394  * Gadgets have a mostly-portable "gadget driver" implementing device
395  * functions, handling all usb configurations and interfaces.  Gadget
396  * drivers talk to hardware-specific code indirectly, through ops vectors.
397  * That insulates the gadget driver from hardware details, and packages
398  * the hardware endpoints through generic i/o queues.  The "usb_gadget"
399  * and "usb_ep" interfaces provide that insulation from the hardware.
400  *
401  * Except for the driver data, all fields in this structure are
402  * read-only to the gadget driver.  That driver data is part of the
403  * "driver model" infrastructure in 2.6 (and later) kernels, and for
404  * earlier systems is grouped in a similar structure that's not known
405  * to the rest of the kernel.
406  *
407  * Values of the three OTG device feature flags are updated before the
408  * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
409  * driver suspend() calls.  They are valid only when is_otg, and when the
410  * device is acting as a B-Peripheral (so is_a_peripheral is false).
411  */
412 struct usb_gadget {
413 	struct work_struct		work;
414 	struct usb_udc			*udc;
415 	/* readonly to gadget driver */
416 	const struct usb_gadget_ops	*ops;
417 	struct usb_ep			*ep0;
418 	struct list_head		ep_list;	/* of usb_ep */
419 	enum usb_device_speed		speed;
420 	enum usb_device_speed		max_speed;
421 
422 	/* USB SuperSpeed Plus only */
423 	enum usb_ssp_rate		ssp_rate;
424 	enum usb_ssp_rate		max_ssp_rate;
425 
426 	enum usb_device_state		state;
427 	const char			*name;
428 	struct device			dev;
429 	unsigned			isoch_delay;
430 	unsigned			out_epnum;
431 	unsigned			in_epnum;
432 	unsigned			mA;
433 	struct usb_otg_caps		*otg_caps;
434 
435 	unsigned			sg_supported:1;
436 	unsigned			is_otg:1;
437 	unsigned			is_a_peripheral:1;
438 	unsigned			b_hnp_enable:1;
439 	unsigned			a_hnp_support:1;
440 	unsigned			a_alt_hnp_support:1;
441 	unsigned			hnp_polling_support:1;
442 	unsigned			host_request_flag:1;
443 	unsigned			quirk_ep_out_aligned_size:1;
444 	unsigned			quirk_altset_not_supp:1;
445 	unsigned			quirk_stall_not_supp:1;
446 	unsigned			quirk_zlp_not_supp:1;
447 	unsigned			quirk_avoids_skb_reserve:1;
448 	unsigned			is_selfpowered:1;
449 	unsigned			deactivated:1;
450 	unsigned			connected:1;
451 	unsigned			lpm_capable:1;
452 	unsigned			wakeup_capable:1;
453 	unsigned			wakeup_armed:1;
454 	int				irq;
455 	int				id_number;
456 };
457 #define work_to_gadget(w)	(container_of((w), struct usb_gadget, work))
458 
459 /* Interface to the device model */
set_gadget_data(struct usb_gadget * gadget,void * data)460 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
461 	{ dev_set_drvdata(&gadget->dev, data); }
get_gadget_data(struct usb_gadget * gadget)462 static inline void *get_gadget_data(struct usb_gadget *gadget)
463 	{ return dev_get_drvdata(&gadget->dev); }
dev_to_usb_gadget(struct device * dev)464 static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
465 {
466 	return container_of(dev, struct usb_gadget, dev);
467 }
usb_get_gadget(struct usb_gadget * gadget)468 static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
469 {
470 	get_device(&gadget->dev);
471 	return gadget;
472 }
usb_put_gadget(struct usb_gadget * gadget)473 static inline void usb_put_gadget(struct usb_gadget *gadget)
474 {
475 	put_device(&gadget->dev);
476 }
477 extern void usb_initialize_gadget(struct device *parent,
478 		struct usb_gadget *gadget, void (*release)(struct device *dev));
479 extern int usb_add_gadget(struct usb_gadget *gadget);
480 extern void usb_del_gadget(struct usb_gadget *gadget);
481 
482 /* Legacy device-model interface */
483 extern int usb_add_gadget_udc_release(struct device *parent,
484 		struct usb_gadget *gadget, void (*release)(struct device *dev));
485 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
486 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
487 extern char *usb_get_gadget_udc_name(void);
488 
489 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
490 #define gadget_for_each_ep(tmp, gadget) \
491 	list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
492 
493 /**
494  * usb_ep_align - returns @len aligned to ep's maxpacketsize.
495  * @ep: the endpoint whose maxpacketsize is used to align @len
496  * @len: buffer size's length to align to @ep's maxpacketsize
497  *
498  * This helper is used to align buffer's size to an ep's maxpacketsize.
499  */
usb_ep_align(struct usb_ep * ep,size_t len)500 static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
501 {
502 	int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc);
503 
504 	return round_up(len, max_packet_size);
505 }
506 
507 /**
508  * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
509  *	requires quirk_ep_out_aligned_size, otherwise returns len.
510  * @g: controller to check for quirk
511  * @ep: the endpoint whose maxpacketsize is used to align @len
512  * @len: buffer size's length to align to @ep's maxpacketsize
513  *
514  * This helper is used in case it's required for any reason to check and maybe
515  * align buffer's size to an ep's maxpacketsize.
516  */
517 static inline size_t
usb_ep_align_maybe(struct usb_gadget * g,struct usb_ep * ep,size_t len)518 usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
519 {
520 	return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
521 }
522 
523 /**
524  * gadget_is_altset_supported - return true iff the hardware supports
525  *	altsettings
526  * @g: controller to check for quirk
527  */
gadget_is_altset_supported(struct usb_gadget * g)528 static inline int gadget_is_altset_supported(struct usb_gadget *g)
529 {
530 	return !g->quirk_altset_not_supp;
531 }
532 
533 /**
534  * gadget_is_stall_supported - return true iff the hardware supports stalling
535  * @g: controller to check for quirk
536  */
gadget_is_stall_supported(struct usb_gadget * g)537 static inline int gadget_is_stall_supported(struct usb_gadget *g)
538 {
539 	return !g->quirk_stall_not_supp;
540 }
541 
542 /**
543  * gadget_is_zlp_supported - return true iff the hardware supports zlp
544  * @g: controller to check for quirk
545  */
gadget_is_zlp_supported(struct usb_gadget * g)546 static inline int gadget_is_zlp_supported(struct usb_gadget *g)
547 {
548 	return !g->quirk_zlp_not_supp;
549 }
550 
551 /**
552  * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
553  *	skb_reserve to improve performance.
554  * @g: controller to check for quirk
555  */
gadget_avoids_skb_reserve(struct usb_gadget * g)556 static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
557 {
558 	return g->quirk_avoids_skb_reserve;
559 }
560 
561 /**
562  * gadget_is_dualspeed - return true iff the hardware handles high speed
563  * @g: controller that might support both high and full speeds
564  */
gadget_is_dualspeed(struct usb_gadget * g)565 static inline int gadget_is_dualspeed(struct usb_gadget *g)
566 {
567 	return g->max_speed >= USB_SPEED_HIGH;
568 }
569 
570 /**
571  * gadget_is_superspeed() - return true if the hardware handles superspeed
572  * @g: controller that might support superspeed
573  */
gadget_is_superspeed(struct usb_gadget * g)574 static inline int gadget_is_superspeed(struct usb_gadget *g)
575 {
576 	return g->max_speed >= USB_SPEED_SUPER;
577 }
578 
579 /**
580  * gadget_is_superspeed_plus() - return true if the hardware handles
581  *	superspeed plus
582  * @g: controller that might support superspeed plus
583  */
gadget_is_superspeed_plus(struct usb_gadget * g)584 static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
585 {
586 	return g->max_speed >= USB_SPEED_SUPER_PLUS;
587 }
588 
589 /**
590  * gadget_is_otg - return true iff the hardware is OTG-ready
591  * @g: controller that might have a Mini-AB connector
592  *
593  * This is a runtime test, since kernels with a USB-OTG stack sometimes
594  * run on boards which only have a Mini-B (or Mini-A) connector.
595  */
gadget_is_otg(struct usb_gadget * g)596 static inline int gadget_is_otg(struct usb_gadget *g)
597 {
598 #ifdef CONFIG_USB_OTG
599 	return g->is_otg;
600 #else
601 	return 0;
602 #endif
603 }
604 
605 /*-------------------------------------------------------------------------*/
606 
607 #if IS_ENABLED(CONFIG_USB_GADGET)
608 int usb_gadget_frame_number(struct usb_gadget *gadget);
609 int usb_gadget_wakeup(struct usb_gadget *gadget);
610 int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
611 int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
612 int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
613 int usb_gadget_vbus_connect(struct usb_gadget *gadget);
614 int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
615 int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
616 int usb_gadget_connect(struct usb_gadget *gadget);
617 int usb_gadget_disconnect(struct usb_gadget *gadget);
618 int usb_gadget_deactivate(struct usb_gadget *gadget);
619 int usb_gadget_activate(struct usb_gadget *gadget);
620 int usb_gadget_check_config(struct usb_gadget *gadget);
621 #else
usb_gadget_frame_number(struct usb_gadget * gadget)622 static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
623 { return 0; }
usb_gadget_wakeup(struct usb_gadget * gadget)624 static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
625 { return 0; }
usb_gadget_set_remote_wakeup(struct usb_gadget * gadget,int set)626 static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
627 { return 0; }
usb_gadget_set_selfpowered(struct usb_gadget * gadget)628 static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
629 { return 0; }
usb_gadget_clear_selfpowered(struct usb_gadget * gadget)630 static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
631 { return 0; }
usb_gadget_vbus_connect(struct usb_gadget * gadget)632 static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
633 { return 0; }
usb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)634 static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
635 { return 0; }
usb_gadget_vbus_disconnect(struct usb_gadget * gadget)636 static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
637 { return 0; }
usb_gadget_connect(struct usb_gadget * gadget)638 static inline int usb_gadget_connect(struct usb_gadget *gadget)
639 { return 0; }
usb_gadget_disconnect(struct usb_gadget * gadget)640 static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
641 { return 0; }
usb_gadget_deactivate(struct usb_gadget * gadget)642 static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
643 { return 0; }
usb_gadget_activate(struct usb_gadget * gadget)644 static inline int usb_gadget_activate(struct usb_gadget *gadget)
645 { return 0; }
usb_gadget_check_config(struct usb_gadget * gadget)646 static inline int usb_gadget_check_config(struct usb_gadget *gadget)
647 { return 0; }
648 #endif /* CONFIG_USB_GADGET */
649 
650 /*-------------------------------------------------------------------------*/
651 
652 /**
653  * struct usb_gadget_driver - driver for usb gadget devices
654  * @function: String describing the gadget's function
655  * @max_speed: Highest speed the driver handles.
656  * @setup: Invoked for ep0 control requests that aren't handled by
657  *	the hardware level driver. Most calls must be handled by
658  *	the gadget driver, including descriptor and configuration
659  *	management.  The 16 bit members of the setup data are in
660  *	USB byte order. Called in_interrupt; this may not sleep.  Driver
661  *	queues a response to ep0, or returns negative to stall.
662  * @disconnect: Invoked after all transfers have been stopped,
663  *	when the host is disconnected.  May be called in_interrupt; this
664  *	may not sleep.  Some devices can't detect disconnect, so this might
665  *	not be called except as part of controller shutdown.
666  * @bind: the driver's bind callback
667  * @unbind: Invoked when the driver is unbound from a gadget,
668  *	usually from rmmod (after a disconnect is reported).
669  *	Called in a context that permits sleeping.
670  * @suspend: Invoked on USB suspend.  May be called in_interrupt.
671  * @resume: Invoked on USB resume.  May be called in_interrupt.
672  * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
673  *	and should be called in_interrupt.
674  * @driver: Driver model state for this driver.
675  * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
676  *	this driver will be bound to any available UDC.
677  * @match_existing_only: If udc is not found, return an error and fail
678  *	the driver registration
679  * @is_bound: Allow a driver to be bound to only one gadget
680  *
681  * Devices are disabled till a gadget driver successfully bind()s, which
682  * means the driver will handle setup() requests needed to enumerate (and
683  * meet "chapter 9" requirements) then do some useful work.
684  *
685  * If gadget->is_otg is true, the gadget driver must provide an OTG
686  * descriptor during enumeration, or else fail the bind() call.  In such
687  * cases, no USB traffic may flow until both bind() returns without
688  * having called usb_gadget_disconnect(), and the USB host stack has
689  * initialized.
690  *
691  * Drivers use hardware-specific knowledge to configure the usb hardware.
692  * endpoint addressing is only one of several hardware characteristics that
693  * are in descriptors the ep0 implementation returns from setup() calls.
694  *
695  * Except for ep0 implementation, most driver code shouldn't need change to
696  * run on top of different usb controllers.  It'll use endpoints set up by
697  * that ep0 implementation.
698  *
699  * The usb controller driver handles a few standard usb requests.  Those
700  * include set_address, and feature flags for devices, interfaces, and
701  * endpoints (the get_status, set_feature, and clear_feature requests).
702  *
703  * Accordingly, the driver's setup() callback must always implement all
704  * get_descriptor requests, returning at least a device descriptor and
705  * a configuration descriptor.  Drivers must make sure the endpoint
706  * descriptors match any hardware constraints. Some hardware also constrains
707  * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
708  *
709  * The driver's setup() callback must also implement set_configuration,
710  * and should also implement set_interface, get_configuration, and
711  * get_interface.  Setting a configuration (or interface) is where
712  * endpoints should be activated or (config 0) shut down.
713  *
714  * (Note that only the default control endpoint is supported.  Neither
715  * hosts nor devices generally support control traffic except to ep0.)
716  *
717  * Most devices will ignore USB suspend/resume operations, and so will
718  * not provide those callbacks.  However, some may need to change modes
719  * when the host is not longer directing those activities.  For example,
720  * local controls (buttons, dials, etc) may need to be re-enabled since
721  * the (remote) host can't do that any longer; or an error state might
722  * be cleared, to make the device behave identically whether or not
723  * power is maintained.
724  */
725 struct usb_gadget_driver {
726 	char			*function;
727 	enum usb_device_speed	max_speed;
728 	int			(*bind)(struct usb_gadget *gadget,
729 					struct usb_gadget_driver *driver);
730 	void			(*unbind)(struct usb_gadget *);
731 	int			(*setup)(struct usb_gadget *,
732 					const struct usb_ctrlrequest *);
733 	void			(*disconnect)(struct usb_gadget *);
734 	void			(*suspend)(struct usb_gadget *);
735 	void			(*resume)(struct usb_gadget *);
736 	void			(*reset)(struct usb_gadget *);
737 
738 	/* FIXME support safe rmmod */
739 	struct device_driver	driver;
740 
741 	char			*udc_name;
742 	unsigned                match_existing_only:1;
743 	bool			is_bound:1;
744 };
745 
746 
747 
748 /*-------------------------------------------------------------------------*/
749 
750 /* driver modules register and unregister, as usual.
751  * these calls must be made in a context that can sleep.
752  *
753  * A gadget driver can be bound to only one gadget at a time.
754  */
755 
756 /**
757  * usb_gadget_register_driver_owner - register a gadget driver
758  * @driver: the driver being registered
759  * @owner: the driver module
760  * @mod_name: the driver module's build name
761  * Context: can sleep
762  *
763  * Call this in your gadget driver's module initialization function,
764  * to tell the underlying UDC controller driver about your driver.
765  * The @bind() function will be called to bind it to a gadget before this
766  * registration call returns.  It's expected that the @bind() function will
767  * be in init sections.
768  *
769  * Use the macro defined below instead of calling this directly.
770  */
771 int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver,
772 		struct module *owner, const char *mod_name);
773 
774 /* use a define to avoid include chaining to get THIS_MODULE & friends */
775 #define usb_gadget_register_driver(driver) \
776 	usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME)
777 
778 /**
779  * usb_gadget_unregister_driver - unregister a gadget driver
780  * @driver:the driver being unregistered
781  * Context: can sleep
782  *
783  * Call this in your gadget driver's module cleanup function,
784  * to tell the underlying usb controller that your driver is
785  * going away.  If the controller is connected to a USB host,
786  * it will first disconnect().  The driver is also requested
787  * to unbind() and clean up any device state, before this procedure
788  * finally returns.  It's expected that the unbind() functions
789  * will be in exit sections, so may not be linked in some kernels.
790  */
791 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
792 
793 /*-------------------------------------------------------------------------*/
794 
795 /* utility to simplify dealing with string descriptors */
796 
797 /**
798  * struct usb_string - wraps a C string and its USB id
799  * @id:the (nonzero) ID for this string
800  * @s:the string, in UTF-8 encoding
801  *
802  * If you're using usb_gadget_get_string(), use this to wrap a string
803  * together with its ID.
804  */
805 struct usb_string {
806 	u8			id;
807 	const char		*s;
808 };
809 
810 /**
811  * struct usb_gadget_strings - a set of USB strings in a given language
812  * @language:identifies the strings' language (0x0409 for en-us)
813  * @strings:array of strings with their ids
814  *
815  * If you're using usb_gadget_get_string(), use this to wrap all the
816  * strings for a given language.
817  */
818 struct usb_gadget_strings {
819 	u16			language;	/* 0x0409 for en-us */
820 	struct usb_string	*strings;
821 };
822 
823 struct usb_gadget_string_container {
824 	struct list_head        list;
825 	u8                      *stash[];
826 };
827 
828 /* put descriptor for string with that id into buf (buflen >= 256) */
829 int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
830 
831 /* check if the given language identifier is valid */
832 bool usb_validate_langid(u16 langid);
833 
834 struct gadget_string {
835 	struct config_item item;
836 	struct list_head list;
837 	char string[USB_MAX_STRING_LEN];
838 	struct usb_string usb_string;
839 };
840 
841 #define to_gadget_string(str_item)\
842 container_of(str_item, struct gadget_string, item)
843 
844 /*-------------------------------------------------------------------------*/
845 
846 /* utility to simplify managing config descriptors */
847 
848 /* write vector of descriptors into buffer */
849 int usb_descriptor_fillbuf(void *, unsigned,
850 		const struct usb_descriptor_header **);
851 
852 /* build config descriptor from single descriptor vector */
853 int usb_gadget_config_buf(const struct usb_config_descriptor *config,
854 	void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
855 
856 /* copy a NULL-terminated vector of descriptors */
857 struct usb_descriptor_header **usb_copy_descriptors(
858 		struct usb_descriptor_header **);
859 
860 /**
861  * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
862  * @v: vector of descriptors
863  */
usb_free_descriptors(struct usb_descriptor_header ** v)864 static inline void usb_free_descriptors(struct usb_descriptor_header **v)
865 {
866 	kfree(v);
867 }
868 
869 struct usb_function;
870 int usb_assign_descriptors(struct usb_function *f,
871 		struct usb_descriptor_header **fs,
872 		struct usb_descriptor_header **hs,
873 		struct usb_descriptor_header **ss,
874 		struct usb_descriptor_header **ssp);
875 void usb_free_all_descriptors(struct usb_function *f);
876 
877 struct usb_descriptor_header *usb_otg_descriptor_alloc(
878 				struct usb_gadget *gadget);
879 int usb_otg_descriptor_init(struct usb_gadget *gadget,
880 		struct usb_descriptor_header *otg_desc);
881 /*-------------------------------------------------------------------------*/
882 
883 /* utility to simplify map/unmap of usb_requests to/from DMA */
884 
885 #ifdef	CONFIG_HAS_DMA
886 extern int usb_gadget_map_request_by_dev(struct device *dev,
887 		struct usb_request *req, int is_in);
888 extern int usb_gadget_map_request(struct usb_gadget *gadget,
889 		struct usb_request *req, int is_in);
890 
891 extern void usb_gadget_unmap_request_by_dev(struct device *dev,
892 		struct usb_request *req, int is_in);
893 extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
894 		struct usb_request *req, int is_in);
895 #else /* !CONFIG_HAS_DMA */
usb_gadget_map_request_by_dev(struct device * dev,struct usb_request * req,int is_in)896 static inline int usb_gadget_map_request_by_dev(struct device *dev,
897 		struct usb_request *req, int is_in) { return -ENOSYS; }
usb_gadget_map_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)898 static inline int usb_gadget_map_request(struct usb_gadget *gadget,
899 		struct usb_request *req, int is_in) { return -ENOSYS; }
900 
usb_gadget_unmap_request_by_dev(struct device * dev,struct usb_request * req,int is_in)901 static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
902 		struct usb_request *req, int is_in) { }
usb_gadget_unmap_request(struct usb_gadget * gadget,struct usb_request * req,int is_in)903 static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
904 		struct usb_request *req, int is_in) { }
905 #endif /* !CONFIG_HAS_DMA */
906 
907 /*-------------------------------------------------------------------------*/
908 
909 /* utility to set gadget state properly */
910 
911 extern void usb_gadget_set_state(struct usb_gadget *gadget,
912 		enum usb_device_state state);
913 
914 /*-------------------------------------------------------------------------*/
915 
916 /* utility to tell udc core that the bus reset occurs */
917 extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
918 		struct usb_gadget_driver *driver);
919 
920 /*-------------------------------------------------------------------------*/
921 
922 /* utility to give requests back to the gadget layer */
923 
924 extern void usb_gadget_giveback_request(struct usb_ep *ep,
925 		struct usb_request *req);
926 
927 /*-------------------------------------------------------------------------*/
928 
929 /* utility to find endpoint by name */
930 
931 extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
932 		const char *name);
933 
934 /*-------------------------------------------------------------------------*/
935 
936 /* utility to check if endpoint caps match descriptor needs */
937 
938 extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
939 		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
940 		struct usb_ss_ep_comp_descriptor *ep_comp);
941 
942 /*-------------------------------------------------------------------------*/
943 
944 /* utility to update vbus status for udc core, it may be scheduled */
945 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
946 
947 /*-------------------------------------------------------------------------*/
948 
949 /* utility wrapping a simple endpoint selection policy */
950 
951 extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
952 			struct usb_endpoint_descriptor *);
953 
954 
955 extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
956 			struct usb_endpoint_descriptor *,
957 			struct usb_ss_ep_comp_descriptor *);
958 
959 extern void usb_ep_autoconfig_release(struct usb_ep *);
960 
961 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
962 
963 #endif /* __LINUX_USB_GADGET_H */
964