xref: /linux/drivers/usb/gadget/composite.c (revision 0dc1f314f854257eb64dcea604a42a55225453a9)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * composite.c - infrastructure for Composite USB Gadgets
4  *
5  * Copyright (C) 2006-2008 David Brownell
6  */
7 
8 /* #define VERBOSE_DEBUG */
9 
10 #include <linux/kallsyms.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/device.h>
15 #include <linux/utsname.h>
16 #include <linux/bitfield.h>
17 #include <linux/uuid.h>
18 
19 #include <linux/usb/composite.h>
20 #include <linux/usb/otg.h>
21 #include <linux/usb/webusb.h>
22 #include <linux/unaligned.h>
23 
24 #include "u_os_desc.h"
25 
26 /**
27  * struct usb_os_string - represents OS String to be reported by a gadget
28  * @bLength: total length of the entire descritor, always 0x12
29  * @bDescriptorType: USB_DT_STRING
30  * @qwSignature: the OS String proper
31  * @bMS_VendorCode: code used by the host for subsequent requests
32  * @bPad: not used, must be zero
33  */
34 struct usb_os_string {
35 	__u8	bLength;
36 	__u8	bDescriptorType;
37 	__u8	qwSignature[OS_STRING_QW_SIGN_LEN];
38 	__u8	bMS_VendorCode;
39 	__u8	bPad;
40 } __packed;
41 
42 /*
43  * The code in this file is utility code, used to build a gadget driver
44  * from one or more "function" drivers, one or more "configuration"
45  * objects, and a "usb_composite_driver" by gluing them together along
46  * with the relevant device-wide data.
47  */
48 
get_containers_gs(struct usb_gadget_string_container * uc)49 static struct usb_gadget_strings **get_containers_gs(
50 		struct usb_gadget_string_container *uc)
51 {
52 	return (struct usb_gadget_strings **)uc->stash;
53 }
54 
55 /**
56  * function_descriptors() - get function descriptors for speed
57  * @f: the function
58  * @speed: the speed
59  *
60  * Returns the descriptors or NULL if not set.
61  */
62 static struct usb_descriptor_header **
function_descriptors(struct usb_function * f,enum usb_device_speed speed)63 function_descriptors(struct usb_function *f,
64 		     enum usb_device_speed speed)
65 {
66 	struct usb_descriptor_header **descriptors;
67 
68 	/*
69 	 * NOTE: we try to help gadget drivers which might not be setting
70 	 * max_speed appropriately.
71 	 */
72 
73 	switch (speed) {
74 	case USB_SPEED_SUPER_PLUS:
75 		descriptors = f->ssp_descriptors;
76 		if (descriptors)
77 			break;
78 		fallthrough;
79 	case USB_SPEED_SUPER:
80 		descriptors = f->ss_descriptors;
81 		if (descriptors)
82 			break;
83 		fallthrough;
84 	case USB_SPEED_HIGH:
85 		descriptors = f->hs_descriptors;
86 		if (descriptors)
87 			break;
88 		fallthrough;
89 	default:
90 		descriptors = f->fs_descriptors;
91 	}
92 
93 	/*
94 	 * if we can't find any descriptors at all, then this gadget deserves to
95 	 * Oops with a NULL pointer dereference
96 	 */
97 
98 	return descriptors;
99 }
100 
101 /**
102  * next_desc() - advance to the next desc_type descriptor
103  * @t: currect pointer within descriptor array
104  * @desc_type: descriptor type
105  *
106  * Return: next desc_type descriptor or NULL
107  *
108  * Iterate over @t until either desc_type descriptor found or
109  * NULL (that indicates end of list) encountered
110  */
111 static struct usb_descriptor_header**
next_desc(struct usb_descriptor_header ** t,u8 desc_type)112 next_desc(struct usb_descriptor_header **t, u8 desc_type)
113 {
114 	for (; *t; t++) {
115 		if ((*t)->bDescriptorType == desc_type)
116 			return t;
117 	}
118 	return NULL;
119 }
120 
121 /*
122  * for_each_desc() - iterate over desc_type descriptors in the
123  * descriptors list
124  * @start: pointer within descriptor array.
125  * @iter_desc: desc_type descriptor to use as the loop cursor
126  * @desc_type: wanted descriptr type
127  */
128 #define for_each_desc(start, iter_desc, desc_type) \
129 	for (iter_desc = next_desc(start, desc_type); \
130 	     iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
131 
132 /**
133  * config_ep_by_speed_and_alt() - configures the given endpoint
134  * according to gadget speed.
135  * @g: pointer to the gadget
136  * @f: usb function
137  * @_ep: the endpoint to configure
138  * @alt: alternate setting number
139  *
140  * Return: error code, 0 on success
141  *
142  * This function chooses the right descriptors for a given
143  * endpoint according to gadget speed and saves it in the
144  * endpoint desc field. If the endpoint already has a descriptor
145  * assigned to it - overwrites it with currently corresponding
146  * descriptor. The endpoint maxpacket field is updated according
147  * to the chosen descriptor.
148  * Note: the supplied function should hold all the descriptors
149  * for supported speeds
150  */
config_ep_by_speed_and_alt(struct usb_gadget * g,struct usb_function * f,struct usb_ep * _ep,u8 alt)151 int config_ep_by_speed_and_alt(struct usb_gadget *g,
152 				struct usb_function *f,
153 				struct usb_ep *_ep,
154 				u8 alt)
155 {
156 	struct usb_endpoint_descriptor *chosen_desc = NULL;
157 	struct usb_interface_descriptor *int_desc = NULL;
158 	struct usb_descriptor_header **speed_desc = NULL;
159 
160 	struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
161 	int want_comp_desc = 0;
162 
163 	struct usb_descriptor_header **d_spd; /* cursor for speed desc */
164 	struct usb_composite_dev *cdev;
165 	bool incomplete_desc = false;
166 
167 	if (!g || !f || !_ep)
168 		return -EIO;
169 
170 	/* select desired speed */
171 	switch (g->speed) {
172 	case USB_SPEED_SUPER_PLUS:
173 		if (f->ssp_descriptors) {
174 			speed_desc = f->ssp_descriptors;
175 			want_comp_desc = 1;
176 			break;
177 		}
178 		incomplete_desc = true;
179 		fallthrough;
180 	case USB_SPEED_SUPER:
181 		if (f->ss_descriptors) {
182 			speed_desc = f->ss_descriptors;
183 			want_comp_desc = 1;
184 			break;
185 		}
186 		incomplete_desc = true;
187 		fallthrough;
188 	case USB_SPEED_HIGH:
189 		if (f->hs_descriptors) {
190 			speed_desc = f->hs_descriptors;
191 			break;
192 		}
193 		incomplete_desc = true;
194 		fallthrough;
195 	default:
196 		speed_desc = f->fs_descriptors;
197 	}
198 
199 	cdev = get_gadget_data(g);
200 	if (incomplete_desc)
201 		WARNING(cdev,
202 			"%s doesn't hold the descriptors for current speed\n",
203 			f->name);
204 
205 	/* find correct alternate setting descriptor */
206 	for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
207 		int_desc = (struct usb_interface_descriptor *)*d_spd;
208 
209 		if (int_desc->bAlternateSetting == alt) {
210 			speed_desc = d_spd;
211 			goto intf_found;
212 		}
213 	}
214 	return -EIO;
215 
216 intf_found:
217 	/* find descriptors */
218 	for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
219 		chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
220 		if (chosen_desc->bEndpointAddress == _ep->address)
221 			goto ep_found;
222 	}
223 	return -EIO;
224 
225 ep_found:
226 	/* commit results */
227 	_ep->maxpacket = usb_endpoint_maxp(chosen_desc);
228 	_ep->desc = chosen_desc;
229 	_ep->comp_desc = NULL;
230 	_ep->maxburst = 0;
231 	_ep->mult = 1;
232 
233 	if (g->speed == USB_SPEED_HIGH && (usb_endpoint_xfer_isoc(_ep->desc) ||
234 				usb_endpoint_xfer_int(_ep->desc)))
235 		_ep->mult = usb_endpoint_maxp_mult(_ep->desc);
236 
237 	if (!want_comp_desc)
238 		return 0;
239 
240 	/*
241 	 * Companion descriptor should follow EP descriptor
242 	 * USB 3.0 spec, #9.6.7
243 	 */
244 	comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
245 	if (!comp_desc ||
246 	    (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
247 		return -EIO;
248 	_ep->comp_desc = comp_desc;
249 	if (g->speed >= USB_SPEED_SUPER) {
250 		switch (usb_endpoint_type(_ep->desc)) {
251 		case USB_ENDPOINT_XFER_ISOC:
252 			/* mult: bits 1:0 of bmAttributes */
253 			_ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
254 			fallthrough;
255 		case USB_ENDPOINT_XFER_BULK:
256 		case USB_ENDPOINT_XFER_INT:
257 			_ep->maxburst = comp_desc->bMaxBurst + 1;
258 			break;
259 		default:
260 			if (comp_desc->bMaxBurst != 0)
261 				ERROR(cdev, "ep0 bMaxBurst must be 0\n");
262 			_ep->maxburst = 1;
263 			break;
264 		}
265 	}
266 	return 0;
267 }
268 EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
269 
270 /**
271  * config_ep_by_speed() - configures the given endpoint
272  * according to gadget speed.
273  * @g: pointer to the gadget
274  * @f: usb function
275  * @_ep: the endpoint to configure
276  *
277  * Return: error code, 0 on success
278  *
279  * This function chooses the right descriptors for a given
280  * endpoint according to gadget speed and saves it in the
281  * endpoint desc field. If the endpoint already has a descriptor
282  * assigned to it - overwrites it with currently corresponding
283  * descriptor. The endpoint maxpacket field is updated according
284  * to the chosen descriptor.
285  * Note: the supplied function should hold all the descriptors
286  * for supported speeds
287  */
config_ep_by_speed(struct usb_gadget * g,struct usb_function * f,struct usb_ep * _ep)288 int config_ep_by_speed(struct usb_gadget *g,
289 			struct usb_function *f,
290 			struct usb_ep *_ep)
291 {
292 	return config_ep_by_speed_and_alt(g, f, _ep, 0);
293 }
294 EXPORT_SYMBOL_GPL(config_ep_by_speed);
295 
296 /**
297  * usb_add_function() - add a function to a configuration
298  * @config: the configuration
299  * @function: the function being added
300  * Context: single threaded during gadget setup
301  *
302  * After initialization, each configuration must have one or more
303  * functions added to it.  Adding a function involves calling its @bind()
304  * method to allocate resources such as interface and string identifiers
305  * and endpoints.
306  *
307  * This function returns the value of the function's bind(), which is
308  * zero for success else a negative errno value.
309  */
usb_add_function(struct usb_configuration * config,struct usb_function * function)310 int usb_add_function(struct usb_configuration *config,
311 		struct usb_function *function)
312 {
313 	int	value = -EINVAL;
314 
315 	DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
316 			function->name, function,
317 			config->label, config);
318 
319 	if (!function->set_alt || !function->disable)
320 		goto done;
321 
322 	function->config = config;
323 	list_add_tail(&function->list, &config->functions);
324 
325 	if (function->bind_deactivated) {
326 		value = usb_function_deactivate(function);
327 		if (value)
328 			goto done;
329 	}
330 
331 	/* REVISIT *require* function->bind? */
332 	if (function->bind) {
333 		value = function->bind(config, function);
334 		if (value < 0) {
335 			list_del(&function->list);
336 			function->config = NULL;
337 		}
338 	} else
339 		value = 0;
340 
341 	/* We allow configurations that don't work at both speeds.
342 	 * If we run into a lowspeed Linux system, treat it the same
343 	 * as full speed ... it's the function drivers that will need
344 	 * to avoid bulk and ISO transfers.
345 	 */
346 	if (!config->fullspeed && function->fs_descriptors)
347 		config->fullspeed = true;
348 	if (!config->highspeed && function->hs_descriptors)
349 		config->highspeed = true;
350 	if (!config->superspeed && function->ss_descriptors)
351 		config->superspeed = true;
352 	if (!config->superspeed_plus && function->ssp_descriptors)
353 		config->superspeed_plus = true;
354 
355 done:
356 	if (value)
357 		DBG(config->cdev, "adding '%s'/%p --> %d\n",
358 				function->name, function, value);
359 	return value;
360 }
361 EXPORT_SYMBOL_GPL(usb_add_function);
362 
usb_remove_function(struct usb_configuration * c,struct usb_function * f)363 void usb_remove_function(struct usb_configuration *c, struct usb_function *f)
364 {
365 	if (f->disable)
366 		f->disable(f);
367 
368 	bitmap_zero(f->endpoints, 32);
369 	list_del(&f->list);
370 	if (f->unbind)
371 		f->unbind(c, f);
372 
373 	if (f->bind_deactivated)
374 		usb_function_activate(f);
375 }
376 EXPORT_SYMBOL_GPL(usb_remove_function);
377 
378 /**
379  * usb_function_deactivate - prevent function and gadget enumeration
380  * @function: the function that isn't yet ready to respond
381  *
382  * Blocks response of the gadget driver to host enumeration by
383  * preventing the data line pullup from being activated.  This is
384  * normally called during @bind() processing to change from the
385  * initial "ready to respond" state, or when a required resource
386  * becomes available.
387  *
388  * For example, drivers that serve as a passthrough to a userspace
389  * daemon can block enumeration unless that daemon (such as an OBEX,
390  * MTP, or print server) is ready to handle host requests.
391  *
392  * Not all systems support software control of their USB peripheral
393  * data pullups.
394  *
395  * Returns zero on success, else negative errno.
396  */
usb_function_deactivate(struct usb_function * function)397 int usb_function_deactivate(struct usb_function *function)
398 {
399 	struct usb_composite_dev	*cdev = function->config->cdev;
400 	unsigned long			flags;
401 	int				status = 0;
402 
403 	spin_lock_irqsave(&cdev->lock, flags);
404 
405 	if (cdev->deactivations == 0) {
406 		spin_unlock_irqrestore(&cdev->lock, flags);
407 		status = usb_gadget_deactivate(cdev->gadget);
408 		spin_lock_irqsave(&cdev->lock, flags);
409 	}
410 	if (status == 0)
411 		cdev->deactivations++;
412 
413 	spin_unlock_irqrestore(&cdev->lock, flags);
414 	return status;
415 }
416 EXPORT_SYMBOL_GPL(usb_function_deactivate);
417 
418 /**
419  * usb_function_activate - allow function and gadget enumeration
420  * @function: function on which usb_function_activate() was called
421  *
422  * Reverses effect of usb_function_deactivate().  If no more functions
423  * are delaying their activation, the gadget driver will respond to
424  * host enumeration procedures.
425  *
426  * Returns zero on success, else negative errno.
427  */
usb_function_activate(struct usb_function * function)428 int usb_function_activate(struct usb_function *function)
429 {
430 	struct usb_composite_dev	*cdev = function->config->cdev;
431 	unsigned long			flags;
432 	int				status = 0;
433 
434 	spin_lock_irqsave(&cdev->lock, flags);
435 
436 	if (WARN_ON(cdev->deactivations == 0))
437 		status = -EINVAL;
438 	else {
439 		cdev->deactivations--;
440 		if (cdev->deactivations == 0) {
441 			spin_unlock_irqrestore(&cdev->lock, flags);
442 			status = usb_gadget_activate(cdev->gadget);
443 			spin_lock_irqsave(&cdev->lock, flags);
444 		}
445 	}
446 
447 	spin_unlock_irqrestore(&cdev->lock, flags);
448 	return status;
449 }
450 EXPORT_SYMBOL_GPL(usb_function_activate);
451 
452 /**
453  * usb_interface_id() - allocate an unused interface ID
454  * @config: configuration associated with the interface
455  * @function: function handling the interface
456  * Context: single threaded during gadget setup
457  *
458  * usb_interface_id() is called from usb_function.bind() callbacks to
459  * allocate new interface IDs.  The function driver will then store that
460  * ID in interface, association, CDC union, and other descriptors.  It
461  * will also handle any control requests targeted at that interface,
462  * particularly changing its altsetting via set_alt().  There may
463  * also be class-specific or vendor-specific requests to handle.
464  *
465  * All interface identifier should be allocated using this routine, to
466  * ensure that for example different functions don't wrongly assign
467  * different meanings to the same identifier.  Note that since interface
468  * identifiers are configuration-specific, functions used in more than
469  * one configuration (or more than once in a given configuration) need
470  * multiple versions of the relevant descriptors.
471  *
472  * Returns the interface ID which was allocated; or -ENODEV if no
473  * more interface IDs can be allocated.
474  */
usb_interface_id(struct usb_configuration * config,struct usb_function * function)475 int usb_interface_id(struct usb_configuration *config,
476 		struct usb_function *function)
477 {
478 	unsigned id = config->next_interface_id;
479 
480 	if (id < MAX_CONFIG_INTERFACES) {
481 		config->interface[id] = function;
482 		config->next_interface_id = id + 1;
483 		return id;
484 	}
485 	return -ENODEV;
486 }
487 EXPORT_SYMBOL_GPL(usb_interface_id);
488 
489 /**
490  * usb_func_wakeup - sends function wake notification to the host.
491  * @func: function that sends the remote wakeup notification.
492  *
493  * Applicable to devices operating at enhanced superspeed when usb
494  * functions are put in function suspend state and armed for function
495  * remote wakeup. On completion, function wake notification is sent. If
496  * the device is in low power state it tries to bring the device to active
497  * state before sending the wake notification. Since it is a synchronous
498  * call, caller must take care of not calling it in interrupt context.
499  * For devices operating at lower speeds  returns negative errno.
500  *
501  * Returns zero on success, else negative errno.
502  */
usb_func_wakeup(struct usb_function * func)503 int usb_func_wakeup(struct usb_function *func)
504 {
505 	struct usb_gadget	*gadget = func->config->cdev->gadget;
506 	int			id;
507 
508 	if (!gadget->ops->func_wakeup)
509 		return -EOPNOTSUPP;
510 
511 	if (!func->func_wakeup_armed) {
512 		ERROR(func->config->cdev, "not armed for func remote wakeup\n");
513 		return -EINVAL;
514 	}
515 
516 	for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
517 		if (func->config->interface[id] == func)
518 			break;
519 
520 	if (id == MAX_CONFIG_INTERFACES) {
521 		ERROR(func->config->cdev, "Invalid function\n");
522 		return -EINVAL;
523 	}
524 
525 	return gadget->ops->func_wakeup(gadget, id);
526 }
527 EXPORT_SYMBOL_GPL(usb_func_wakeup);
528 
encode_bMaxPower(enum usb_device_speed speed,struct usb_configuration * c)529 static u8 encode_bMaxPower(enum usb_device_speed speed,
530 		struct usb_configuration *c)
531 {
532 	unsigned val;
533 
534 	if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
535 		val = c->MaxPower;
536 	else
537 		val = CONFIG_USB_GADGET_VBUS_DRAW;
538 	if (!val)
539 		return 0;
540 	if (speed < USB_SPEED_SUPER)
541 		return min(val, 500U) / 2;
542 	else
543 		/*
544 		 * USB 3.x supports up to 900mA, but since 900 isn't divisible
545 		 * by 8 the integral division will effectively cap to 896mA.
546 		 */
547 		return min(val, 900U) / 8;
548 }
549 
check_remote_wakeup_config(struct usb_gadget * g,struct usb_configuration * c)550 void check_remote_wakeup_config(struct usb_gadget *g,
551 				struct usb_configuration *c)
552 {
553 	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes) {
554 		/* Reset the rw bit if gadget is not capable of it */
555 		if (!g->wakeup_capable && g->ops->set_remote_wakeup) {
556 			WARN(c->cdev, "Clearing wakeup bit for config c.%d\n",
557 			     c->bConfigurationValue);
558 			c->bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
559 		}
560 	}
561 }
562 
config_buf(struct usb_configuration * config,enum usb_device_speed speed,void * buf,u8 type)563 static int config_buf(struct usb_configuration *config,
564 		enum usb_device_speed speed, void *buf, u8 type)
565 {
566 	struct usb_config_descriptor	*c = buf;
567 	void				*next = buf + USB_DT_CONFIG_SIZE;
568 	int				len;
569 	struct usb_function		*f;
570 	int				status;
571 
572 	len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
573 	/* write the config descriptor */
574 	c = buf;
575 	c->bLength = USB_DT_CONFIG_SIZE;
576 	c->bDescriptorType = type;
577 	/* wTotalLength is written later */
578 	c->bNumInterfaces = config->next_interface_id;
579 	c->bConfigurationValue = config->bConfigurationValue;
580 	c->iConfiguration = config->iConfiguration;
581 	c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
582 	c->bMaxPower = encode_bMaxPower(speed, config);
583 
584 	/* There may be e.g. OTG descriptors */
585 	if (config->descriptors) {
586 		status = usb_descriptor_fillbuf(next, len,
587 				config->descriptors);
588 		if (status < 0)
589 			return status;
590 		len -= status;
591 		next += status;
592 	}
593 
594 	/* add each function's descriptors */
595 	list_for_each_entry(f, &config->functions, list) {
596 		struct usb_descriptor_header **descriptors;
597 
598 		descriptors = function_descriptors(f, speed);
599 		if (!descriptors)
600 			continue;
601 		status = usb_descriptor_fillbuf(next, len,
602 			(const struct usb_descriptor_header **) descriptors);
603 		if (status < 0)
604 			return status;
605 		len -= status;
606 		next += status;
607 	}
608 
609 	len = next - buf;
610 	c->wTotalLength = cpu_to_le16(len);
611 	return len;
612 }
613 
config_desc(struct usb_composite_dev * cdev,unsigned w_value)614 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
615 {
616 	struct usb_gadget		*gadget = cdev->gadget;
617 	struct usb_configuration	*c;
618 	struct list_head		*pos;
619 	u8				type = w_value >> 8;
620 	enum usb_device_speed		speed = USB_SPEED_UNKNOWN;
621 
622 	if (gadget->speed >= USB_SPEED_SUPER)
623 		speed = gadget->speed;
624 	else if (gadget_is_dualspeed(gadget)) {
625 		int	hs = 0;
626 		if (gadget->speed == USB_SPEED_HIGH)
627 			hs = 1;
628 		if (type == USB_DT_OTHER_SPEED_CONFIG)
629 			hs = !hs;
630 		if (hs)
631 			speed = USB_SPEED_HIGH;
632 
633 	}
634 
635 	/* This is a lookup by config *INDEX* */
636 	w_value &= 0xff;
637 
638 	pos = &cdev->configs;
639 	c = cdev->os_desc_config;
640 	if (c)
641 		goto check_config;
642 
643 	while ((pos = pos->next) !=  &cdev->configs) {
644 		c = list_entry(pos, typeof(*c), list);
645 
646 		/* skip OS Descriptors config which is handled separately */
647 		if (c == cdev->os_desc_config)
648 			continue;
649 
650 check_config:
651 		/* ignore configs that won't work at this speed */
652 		switch (speed) {
653 		case USB_SPEED_SUPER_PLUS:
654 			if (!c->superspeed_plus)
655 				continue;
656 			break;
657 		case USB_SPEED_SUPER:
658 			if (!c->superspeed)
659 				continue;
660 			break;
661 		case USB_SPEED_HIGH:
662 			if (!c->highspeed)
663 				continue;
664 			break;
665 		default:
666 			if (!c->fullspeed)
667 				continue;
668 		}
669 
670 		if (w_value == 0)
671 			return config_buf(c, speed, cdev->req->buf, type);
672 		w_value--;
673 	}
674 	return -EINVAL;
675 }
676 
count_configs(struct usb_composite_dev * cdev,unsigned type)677 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
678 {
679 	struct usb_gadget		*gadget = cdev->gadget;
680 	struct usb_configuration	*c;
681 	unsigned			count = 0;
682 	int				hs = 0;
683 	int				ss = 0;
684 	int				ssp = 0;
685 
686 	if (gadget_is_dualspeed(gadget)) {
687 		if (gadget->speed == USB_SPEED_HIGH)
688 			hs = 1;
689 		if (gadget->speed == USB_SPEED_SUPER)
690 			ss = 1;
691 		if (gadget->speed == USB_SPEED_SUPER_PLUS)
692 			ssp = 1;
693 		if (type == USB_DT_DEVICE_QUALIFIER)
694 			hs = !hs;
695 	}
696 	list_for_each_entry(c, &cdev->configs, list) {
697 		/* ignore configs that won't work at this speed */
698 		if (ssp) {
699 			if (!c->superspeed_plus)
700 				continue;
701 		} else if (ss) {
702 			if (!c->superspeed)
703 				continue;
704 		} else if (hs) {
705 			if (!c->highspeed)
706 				continue;
707 		} else {
708 			if (!c->fullspeed)
709 				continue;
710 		}
711 		count++;
712 	}
713 	return count;
714 }
715 
716 /**
717  * bos_desc() - prepares the BOS descriptor.
718  * @cdev: pointer to usb_composite device to generate the bos
719  *	descriptor for
720  *
721  * This function generates the BOS (Binary Device Object)
722  * descriptor and its device capabilities descriptors. The BOS
723  * descriptor should be supported by a SuperSpeed device.
724  */
bos_desc(struct usb_composite_dev * cdev)725 static int bos_desc(struct usb_composite_dev *cdev)
726 {
727 	struct usb_ext_cap_descriptor	*usb_ext;
728 	struct usb_dcd_config_params	dcd_config_params;
729 	struct usb_bos_descriptor	*bos = cdev->req->buf;
730 	unsigned int			besl = 0;
731 
732 	bos->bLength = USB_DT_BOS_SIZE;
733 	bos->bDescriptorType = USB_DT_BOS;
734 
735 	bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
736 	bos->bNumDeviceCaps = 0;
737 
738 	/* Get Controller configuration */
739 	if (cdev->gadget->ops->get_config_params) {
740 		cdev->gadget->ops->get_config_params(cdev->gadget,
741 						     &dcd_config_params);
742 	} else {
743 		dcd_config_params.besl_baseline =
744 			USB_DEFAULT_BESL_UNSPECIFIED;
745 		dcd_config_params.besl_deep =
746 			USB_DEFAULT_BESL_UNSPECIFIED;
747 		dcd_config_params.bU1devExitLat =
748 			USB_DEFAULT_U1_DEV_EXIT_LAT;
749 		dcd_config_params.bU2DevExitLat =
750 			cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
751 	}
752 
753 	if (dcd_config_params.besl_baseline != USB_DEFAULT_BESL_UNSPECIFIED)
754 		besl = USB_BESL_BASELINE_VALID |
755 			USB_SET_BESL_BASELINE(dcd_config_params.besl_baseline);
756 
757 	if (dcd_config_params.besl_deep != USB_DEFAULT_BESL_UNSPECIFIED)
758 		besl |= USB_BESL_DEEP_VALID |
759 			USB_SET_BESL_DEEP(dcd_config_params.besl_deep);
760 
761 	/*
762 	 * A SuperSpeed device shall include the USB2.0 extension descriptor
763 	 * and shall support LPM when operating in USB2.0 HS mode.
764 	 */
765 	if (cdev->gadget->lpm_capable) {
766 		usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
767 		bos->bNumDeviceCaps++;
768 		le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
769 		usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
770 		usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
771 		usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
772 		usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT |
773 							USB_BESL_SUPPORT | besl);
774 	}
775 
776 	/*
777 	 * The Superspeed USB Capability descriptor shall be implemented by all
778 	 * SuperSpeed devices.
779 	 */
780 	if (gadget_is_superspeed(cdev->gadget)) {
781 		struct usb_ss_cap_descriptor *ss_cap;
782 
783 		ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
784 		bos->bNumDeviceCaps++;
785 		le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
786 		ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
787 		ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
788 		ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
789 		ss_cap->bmAttributes = 0; /* LTM is not supported yet */
790 		ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
791 						      USB_FULL_SPEED_OPERATION |
792 						      USB_HIGH_SPEED_OPERATION |
793 						      USB_5GBPS_OPERATION);
794 		ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
795 		ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
796 		ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
797 	}
798 
799 	/* The SuperSpeedPlus USB Device Capability descriptor */
800 	if (gadget_is_superspeed_plus(cdev->gadget)) {
801 		struct usb_ssp_cap_descriptor *ssp_cap;
802 		u8 ssac = 1;
803 		u8 ssic;
804 		int i;
805 
806 		if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x2)
807 			ssac = 3;
808 
809 		/*
810 		 * Paired RX and TX sublink speed attributes share
811 		 * the same SSID.
812 		 */
813 		ssic = (ssac + 1) / 2 - 1;
814 
815 		ssp_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
816 		bos->bNumDeviceCaps++;
817 
818 		le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SSP_CAP_SIZE(ssac));
819 		ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
820 		ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
821 		ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
822 		ssp_cap->bReserved = 0;
823 		ssp_cap->wReserved = 0;
824 
825 		ssp_cap->bmAttributes =
826 			cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
827 				    FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
828 
829 		ssp_cap->wFunctionalitySupport =
830 			cpu_to_le16(FIELD_PREP(USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID, 0) |
831 				    FIELD_PREP(USB_SSP_MIN_RX_LANE_COUNT, 1) |
832 				    FIELD_PREP(USB_SSP_MIN_TX_LANE_COUNT, 1));
833 
834 		/*
835 		 * Use 1 SSID if the gadget supports up to gen2x1 or not
836 		 * specified:
837 		 * - SSID 0 for symmetric RX/TX sublink speed of 10 Gbps.
838 		 *
839 		 * Use 1 SSID if the gadget supports up to gen1x2:
840 		 * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
841 		 *
842 		 * Use 2 SSIDs if the gadget supports up to gen2x2:
843 		 * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
844 		 * - SSID 1 for symmetric RX/TX sublink speed of 10 Gbps.
845 		 */
846 		for (i = 0; i < ssac + 1; i++) {
847 			u8 ssid;
848 			u8 mantissa;
849 			u8 type;
850 
851 			ssid = i >> 1;
852 
853 			if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x1 ||
854 			    cdev->gadget->max_ssp_rate == USB_SSP_GEN_UNKNOWN)
855 				mantissa = 10;
856 			else
857 				mantissa = 5 << ssid;
858 
859 			if (i % 2)
860 				type = USB_SSP_SUBLINK_SPEED_ST_SYM_TX;
861 			else
862 				type = USB_SSP_SUBLINK_SPEED_ST_SYM_RX;
863 
864 			ssp_cap->bmSublinkSpeedAttr[i] =
865 				cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_SSID, ssid) |
866 					    FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSE,
867 						       USB_SSP_SUBLINK_SPEED_LSE_GBPS) |
868 					    FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST, type) |
869 					    FIELD_PREP(USB_SSP_SUBLINK_SPEED_LP,
870 						       USB_SSP_SUBLINK_SPEED_LP_SSP) |
871 					    FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSM, mantissa));
872 		}
873 	}
874 
875 	/* The WebUSB Platform Capability descriptor */
876 	if (cdev->use_webusb) {
877 		struct usb_plat_dev_cap_descriptor *webusb_cap;
878 		struct usb_webusb_cap_data *webusb_cap_data;
879 		guid_t webusb_uuid = WEBUSB_UUID;
880 
881 		webusb_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
882 		webusb_cap_data = (struct usb_webusb_cap_data *) webusb_cap->CapabilityData;
883 		bos->bNumDeviceCaps++;
884 		le16_add_cpu(&bos->wTotalLength,
885 			USB_DT_USB_PLAT_DEV_CAP_SIZE(USB_WEBUSB_CAP_DATA_SIZE));
886 
887 		webusb_cap->bLength = USB_DT_USB_PLAT_DEV_CAP_SIZE(USB_WEBUSB_CAP_DATA_SIZE);
888 		webusb_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
889 		webusb_cap->bDevCapabilityType = USB_PLAT_DEV_CAP_TYPE;
890 		webusb_cap->bReserved = 0;
891 		export_guid(webusb_cap->UUID, &webusb_uuid);
892 
893 		if (cdev->bcd_webusb_version != 0)
894 			webusb_cap_data->bcdVersion = cpu_to_le16(cdev->bcd_webusb_version);
895 		else
896 			webusb_cap_data->bcdVersion = WEBUSB_VERSION_1_00;
897 
898 		webusb_cap_data->bVendorCode = cdev->b_webusb_vendor_code;
899 
900 		if (strnlen(cdev->landing_page, sizeof(cdev->landing_page)) > 0)
901 			webusb_cap_data->iLandingPage = WEBUSB_LANDING_PAGE_PRESENT;
902 		else
903 			webusb_cap_data->iLandingPage = WEBUSB_LANDING_PAGE_NOT_PRESENT;
904 	}
905 
906 	return le16_to_cpu(bos->wTotalLength);
907 }
908 
device_qual(struct usb_composite_dev * cdev)909 static void device_qual(struct usb_composite_dev *cdev)
910 {
911 	struct usb_qualifier_descriptor	*qual = cdev->req->buf;
912 
913 	qual->bLength = sizeof(*qual);
914 	qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
915 	/* POLICY: same bcdUSB and device type info at both speeds */
916 	qual->bcdUSB = cdev->desc.bcdUSB;
917 	qual->bDeviceClass = cdev->desc.bDeviceClass;
918 	qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
919 	qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
920 	/* ASSUME same EP0 fifo size at both speeds */
921 	qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
922 	qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
923 	qual->bRESERVED = 0;
924 }
925 
926 /*-------------------------------------------------------------------------*/
927 
reset_config(struct usb_composite_dev * cdev)928 static void reset_config(struct usb_composite_dev *cdev)
929 {
930 	struct usb_function		*f;
931 
932 	DBG(cdev, "reset config\n");
933 
934 	list_for_each_entry(f, &cdev->config->functions, list) {
935 		if (f->disable)
936 			f->disable(f);
937 
938 		/* Section 9.1.1.6, disable remote wakeup when device is reset */
939 		f->func_wakeup_armed = false;
940 
941 		bitmap_zero(f->endpoints, 32);
942 	}
943 	cdev->config = NULL;
944 	cdev->delayed_status = 0;
945 }
946 
set_config(struct usb_composite_dev * cdev,const struct usb_ctrlrequest * ctrl,unsigned number)947 static int set_config(struct usb_composite_dev *cdev,
948 		const struct usb_ctrlrequest *ctrl, unsigned number)
949 {
950 	struct usb_gadget	*gadget = cdev->gadget;
951 	struct usb_configuration *c = NULL, *iter;
952 	int			result = -EINVAL;
953 	unsigned		power = gadget_is_otg(gadget) ? 8 : 100;
954 	int			tmp;
955 
956 	if (number) {
957 		list_for_each_entry(iter, &cdev->configs, list) {
958 			if (iter->bConfigurationValue != number)
959 				continue;
960 			/*
961 			 * We disable the FDs of the previous
962 			 * configuration only if the new configuration
963 			 * is a valid one
964 			 */
965 			if (cdev->config)
966 				reset_config(cdev);
967 			c = iter;
968 			result = 0;
969 			break;
970 		}
971 		if (result < 0)
972 			goto done;
973 	} else { /* Zero configuration value - need to reset the config */
974 		if (cdev->config)
975 			reset_config(cdev);
976 		result = 0;
977 	}
978 
979 	DBG(cdev, "%s config #%d: %s\n",
980 	    usb_speed_string(gadget->speed),
981 	    number, c ? c->label : "unconfigured");
982 
983 	if (!c)
984 		goto done;
985 
986 	usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
987 	cdev->config = c;
988 
989 	/* Initialize all interfaces by setting them to altsetting zero. */
990 	for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
991 		struct usb_function	*f = c->interface[tmp];
992 		struct usb_descriptor_header **descriptors;
993 
994 		if (!f)
995 			break;
996 
997 		/*
998 		 * Record which endpoints are used by the function. This is used
999 		 * to dispatch control requests targeted at that endpoint to the
1000 		 * function's setup callback instead of the current
1001 		 * configuration's setup callback.
1002 		 */
1003 		descriptors = function_descriptors(f, gadget->speed);
1004 
1005 		for (; *descriptors; ++descriptors) {
1006 			struct usb_endpoint_descriptor *ep;
1007 			int addr;
1008 
1009 			if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
1010 				continue;
1011 
1012 			ep = (struct usb_endpoint_descriptor *)*descriptors;
1013 			addr = ((ep->bEndpointAddress & 0x80) >> 3)
1014 			     |  (ep->bEndpointAddress & 0x0f);
1015 			set_bit(addr, f->endpoints);
1016 		}
1017 
1018 		result = f->set_alt(f, tmp, 0);
1019 		if (result < 0) {
1020 			DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
1021 					tmp, f->name, f, result);
1022 
1023 			reset_config(cdev);
1024 			goto done;
1025 		}
1026 
1027 		if (result == USB_GADGET_DELAYED_STATUS) {
1028 			DBG(cdev,
1029 			 "%s: interface %d (%s) requested delayed status\n",
1030 					__func__, tmp, f->name);
1031 			cdev->delayed_status++;
1032 			DBG(cdev, "delayed_status count %d\n",
1033 					cdev->delayed_status);
1034 		}
1035 	}
1036 
1037 	/* when we return, be sure our power usage is valid */
1038 	if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
1039 		power = c->MaxPower;
1040 	else
1041 		power = CONFIG_USB_GADGET_VBUS_DRAW;
1042 
1043 	if (gadget->speed < USB_SPEED_SUPER)
1044 		power = min(power, 500U);
1045 	else
1046 		power = min(power, 900U);
1047 
1048 	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes)
1049 		usb_gadget_set_remote_wakeup(gadget, 1);
1050 	else
1051 		usb_gadget_set_remote_wakeup(gadget, 0);
1052 done:
1053 	if (power > USB_SELF_POWER_VBUS_MAX_DRAW ||
1054 	    (c && !(c->bmAttributes & USB_CONFIG_ATT_SELFPOWER)))
1055 		usb_gadget_clear_selfpowered(gadget);
1056 	else
1057 		usb_gadget_set_selfpowered(gadget);
1058 
1059 	usb_gadget_vbus_draw(gadget, power);
1060 	if (result >= 0 && cdev->delayed_status)
1061 		result = USB_GADGET_DELAYED_STATUS;
1062 	return result;
1063 }
1064 
usb_add_config_only(struct usb_composite_dev * cdev,struct usb_configuration * config)1065 int usb_add_config_only(struct usb_composite_dev *cdev,
1066 		struct usb_configuration *config)
1067 {
1068 	struct usb_configuration *c;
1069 
1070 	if (!config->bConfigurationValue)
1071 		return -EINVAL;
1072 
1073 	/* Prevent duplicate configuration identifiers */
1074 	list_for_each_entry(c, &cdev->configs, list) {
1075 		if (c->bConfigurationValue == config->bConfigurationValue)
1076 			return -EBUSY;
1077 	}
1078 
1079 	config->cdev = cdev;
1080 	list_add_tail(&config->list, &cdev->configs);
1081 
1082 	INIT_LIST_HEAD(&config->functions);
1083 	config->next_interface_id = 0;
1084 	memset(config->interface, 0, sizeof(config->interface));
1085 
1086 	return 0;
1087 }
1088 EXPORT_SYMBOL_GPL(usb_add_config_only);
1089 
1090 /**
1091  * usb_add_config() - add a configuration to a device.
1092  * @cdev: wraps the USB gadget
1093  * @config: the configuration, with bConfigurationValue assigned
1094  * @bind: the configuration's bind function
1095  * Context: single threaded during gadget setup
1096  *
1097  * One of the main tasks of a composite @bind() routine is to
1098  * add each of the configurations it supports, using this routine.
1099  *
1100  * This function returns the value of the configuration's @bind(), which
1101  * is zero for success else a negative errno value.  Binding configurations
1102  * assigns global resources including string IDs, and per-configuration
1103  * resources such as interface IDs and endpoints.
1104  */
usb_add_config(struct usb_composite_dev * cdev,struct usb_configuration * config,int (* bind)(struct usb_configuration *))1105 int usb_add_config(struct usb_composite_dev *cdev,
1106 		struct usb_configuration *config,
1107 		int (*bind)(struct usb_configuration *))
1108 {
1109 	int				status = -EINVAL;
1110 
1111 	if (!bind)
1112 		goto done;
1113 
1114 	DBG(cdev, "adding config #%u '%s'/%p\n",
1115 			config->bConfigurationValue,
1116 			config->label, config);
1117 
1118 	status = usb_add_config_only(cdev, config);
1119 	if (status)
1120 		goto done;
1121 
1122 	status = bind(config);
1123 
1124 	if (status == 0)
1125 		status = usb_gadget_check_config(cdev->gadget);
1126 
1127 	if (status < 0) {
1128 		while (!list_empty(&config->functions)) {
1129 			struct usb_function		*f;
1130 
1131 			f = list_first_entry(&config->functions,
1132 					struct usb_function, list);
1133 			list_del(&f->list);
1134 			if (f->unbind) {
1135 				DBG(cdev, "unbind function '%s'/%p\n",
1136 					f->name, f);
1137 				f->unbind(config, f);
1138 				/* may free memory for "f" */
1139 			}
1140 		}
1141 		list_del(&config->list);
1142 		config->cdev = NULL;
1143 	} else {
1144 		unsigned	i;
1145 
1146 		DBG(cdev, "cfg %d/%p speeds:%s%s%s%s\n",
1147 			config->bConfigurationValue, config,
1148 			config->superspeed_plus ? " superplus" : "",
1149 			config->superspeed ? " super" : "",
1150 			config->highspeed ? " high" : "",
1151 			config->fullspeed
1152 				? (gadget_is_dualspeed(cdev->gadget)
1153 					? " full"
1154 					: " full/low")
1155 				: "");
1156 
1157 		for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
1158 			struct usb_function	*f = config->interface[i];
1159 
1160 			if (!f)
1161 				continue;
1162 			DBG(cdev, "  interface %d = %s/%p\n",
1163 				i, f->name, f);
1164 		}
1165 	}
1166 
1167 	/* set_alt(), or next bind(), sets up ep->claimed as needed */
1168 	usb_ep_autoconfig_reset(cdev->gadget);
1169 
1170 done:
1171 	if (status)
1172 		DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
1173 				config->bConfigurationValue, status);
1174 	return status;
1175 }
1176 EXPORT_SYMBOL_GPL(usb_add_config);
1177 
remove_config(struct usb_composite_dev * cdev,struct usb_configuration * config)1178 static void remove_config(struct usb_composite_dev *cdev,
1179 			      struct usb_configuration *config)
1180 {
1181 	while (!list_empty(&config->functions)) {
1182 		struct usb_function		*f;
1183 
1184 		f = list_first_entry(&config->functions,
1185 				struct usb_function, list);
1186 
1187 		usb_remove_function(config, f);
1188 	}
1189 	list_del(&config->list);
1190 	if (config->unbind) {
1191 		DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
1192 		config->unbind(config);
1193 			/* may free memory for "c" */
1194 	}
1195 }
1196 
1197 /**
1198  * usb_remove_config() - remove a configuration from a device.
1199  * @cdev: wraps the USB gadget
1200  * @config: the configuration
1201  *
1202  * Drivers must call usb_gadget_disconnect before calling this function
1203  * to disconnect the device from the host and make sure the host will not
1204  * try to enumerate the device while we are changing the config list.
1205  */
usb_remove_config(struct usb_composite_dev * cdev,struct usb_configuration * config)1206 void usb_remove_config(struct usb_composite_dev *cdev,
1207 		      struct usb_configuration *config)
1208 {
1209 	unsigned long flags;
1210 
1211 	spin_lock_irqsave(&cdev->lock, flags);
1212 
1213 	if (cdev->config == config)
1214 		reset_config(cdev);
1215 
1216 	spin_unlock_irqrestore(&cdev->lock, flags);
1217 
1218 	remove_config(cdev, config);
1219 }
1220 
1221 /*-------------------------------------------------------------------------*/
1222 
1223 /* We support strings in multiple languages ... string descriptor zero
1224  * says which languages are supported.  The typical case will be that
1225  * only one language (probably English) is used, with i18n handled on
1226  * the host side.
1227  */
1228 
collect_langs(struct usb_gadget_strings ** sp,__le16 * buf)1229 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
1230 {
1231 	const struct usb_gadget_strings	*s;
1232 	__le16				language;
1233 	__le16				*tmp;
1234 
1235 	while (*sp) {
1236 		s = *sp;
1237 		language = cpu_to_le16(s->language);
1238 		for (tmp = buf; *tmp && tmp < &buf[USB_MAX_STRING_LEN]; tmp++) {
1239 			if (*tmp == language)
1240 				goto repeat;
1241 		}
1242 		*tmp++ = language;
1243 repeat:
1244 		sp++;
1245 	}
1246 }
1247 
lookup_string(struct usb_gadget_strings ** sp,void * buf,u16 language,int id)1248 static int lookup_string(
1249 	struct usb_gadget_strings	**sp,
1250 	void				*buf,
1251 	u16				language,
1252 	int				id
1253 )
1254 {
1255 	struct usb_gadget_strings	*s;
1256 	int				value;
1257 
1258 	while (*sp) {
1259 		s = *sp++;
1260 		if (s->language != language)
1261 			continue;
1262 		value = usb_gadget_get_string(s, id, buf);
1263 		if (value > 0)
1264 			return value;
1265 	}
1266 	return -EINVAL;
1267 }
1268 
get_string(struct usb_composite_dev * cdev,void * buf,u16 language,int id)1269 static int get_string(struct usb_composite_dev *cdev,
1270 		void *buf, u16 language, int id)
1271 {
1272 	struct usb_composite_driver	*composite = cdev->driver;
1273 	struct usb_gadget_string_container *uc;
1274 	struct usb_configuration	*c;
1275 	struct usb_function		*f;
1276 	int				len;
1277 
1278 	/* Yes, not only is USB's i18n support probably more than most
1279 	 * folk will ever care about ... also, it's all supported here.
1280 	 * (Except for UTF8 support for Unicode's "Astral Planes".)
1281 	 */
1282 
1283 	/* 0 == report all available language codes */
1284 	if (id == 0) {
1285 		struct usb_string_descriptor	*s = buf;
1286 		struct usb_gadget_strings	**sp;
1287 
1288 		memset(s, 0, 256);
1289 		s->bDescriptorType = USB_DT_STRING;
1290 
1291 		sp = composite->strings;
1292 		if (sp)
1293 			collect_langs(sp, s->wData);
1294 
1295 		list_for_each_entry(c, &cdev->configs, list) {
1296 			sp = c->strings;
1297 			if (sp)
1298 				collect_langs(sp, s->wData);
1299 
1300 			list_for_each_entry(f, &c->functions, list) {
1301 				sp = f->strings;
1302 				if (sp)
1303 					collect_langs(sp, s->wData);
1304 			}
1305 		}
1306 		list_for_each_entry(uc, &cdev->gstrings, list) {
1307 			struct usb_gadget_strings **sp;
1308 
1309 			sp = get_containers_gs(uc);
1310 			collect_langs(sp, s->wData);
1311 		}
1312 
1313 		for (len = 0; len <= USB_MAX_STRING_LEN && s->wData[len]; len++)
1314 			continue;
1315 		if (!len)
1316 			return -EINVAL;
1317 
1318 		s->bLength = 2 * (len + 1);
1319 		return s->bLength;
1320 	}
1321 
1322 	if (cdev->use_os_string && language == 0 && id == OS_STRING_IDX) {
1323 		struct usb_os_string *b = buf;
1324 		b->bLength = sizeof(*b);
1325 		b->bDescriptorType = USB_DT_STRING;
1326 		compiletime_assert(
1327 			sizeof(b->qwSignature) == sizeof(cdev->qw_sign),
1328 			"qwSignature size must be equal to qw_sign");
1329 		memcpy(&b->qwSignature, cdev->qw_sign, sizeof(b->qwSignature));
1330 		b->bMS_VendorCode = cdev->b_vendor_code;
1331 		b->bPad = 0;
1332 		return sizeof(*b);
1333 	}
1334 
1335 	list_for_each_entry(uc, &cdev->gstrings, list) {
1336 		struct usb_gadget_strings **sp;
1337 
1338 		sp = get_containers_gs(uc);
1339 		len = lookup_string(sp, buf, language, id);
1340 		if (len > 0)
1341 			return len;
1342 	}
1343 
1344 	/* String IDs are device-scoped, so we look up each string
1345 	 * table we're told about.  These lookups are infrequent;
1346 	 * simpler-is-better here.
1347 	 */
1348 	if (composite->strings) {
1349 		len = lookup_string(composite->strings, buf, language, id);
1350 		if (len > 0)
1351 			return len;
1352 	}
1353 	list_for_each_entry(c, &cdev->configs, list) {
1354 		if (c->strings) {
1355 			len = lookup_string(c->strings, buf, language, id);
1356 			if (len > 0)
1357 				return len;
1358 		}
1359 		list_for_each_entry(f, &c->functions, list) {
1360 			if (!f->strings)
1361 				continue;
1362 			len = lookup_string(f->strings, buf, language, id);
1363 			if (len > 0)
1364 				return len;
1365 		}
1366 	}
1367 	return -EINVAL;
1368 }
1369 
1370 /**
1371  * usb_string_id() - allocate an unused string ID
1372  * @cdev: the device whose string descriptor IDs are being allocated
1373  * Context: single threaded during gadget setup
1374  *
1375  * @usb_string_id() is called from bind() callbacks to allocate
1376  * string IDs.  Drivers for functions, configurations, or gadgets will
1377  * then store that ID in the appropriate descriptors and string table.
1378  *
1379  * All string identifier should be allocated using this,
1380  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
1381  * that for example different functions don't wrongly assign different
1382  * meanings to the same identifier.
1383  */
usb_string_id(struct usb_composite_dev * cdev)1384 int usb_string_id(struct usb_composite_dev *cdev)
1385 {
1386 	if (cdev->next_string_id < 254) {
1387 		/* string id 0 is reserved by USB spec for list of
1388 		 * supported languages */
1389 		/* 255 reserved as well? -- mina86 */
1390 		cdev->next_string_id++;
1391 		return cdev->next_string_id;
1392 	}
1393 	return -ENODEV;
1394 }
1395 EXPORT_SYMBOL_GPL(usb_string_id);
1396 
1397 /**
1398  * usb_string_ids_tab() - allocate unused string IDs in batch
1399  * @cdev: the device whose string descriptor IDs are being allocated
1400  * @str: an array of usb_string objects to assign numbers to
1401  * Context: single threaded during gadget setup
1402  *
1403  * @usb_string_ids() is called from bind() callbacks to allocate
1404  * string IDs.  Drivers for functions, configurations, or gadgets will
1405  * then copy IDs from the string table to the appropriate descriptors
1406  * and string table for other languages.
1407  *
1408  * All string identifier should be allocated using this,
1409  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1410  * example different functions don't wrongly assign different meanings
1411  * to the same identifier.
1412  */
usb_string_ids_tab(struct usb_composite_dev * cdev,struct usb_string * str)1413 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
1414 {
1415 	int next = cdev->next_string_id;
1416 
1417 	for (; str->s; ++str) {
1418 		if (unlikely(next >= 254))
1419 			return -ENODEV;
1420 		str->id = ++next;
1421 	}
1422 
1423 	cdev->next_string_id = next;
1424 
1425 	return 0;
1426 }
1427 EXPORT_SYMBOL_GPL(usb_string_ids_tab);
1428 
copy_gadget_strings(struct usb_gadget_strings ** sp,unsigned n_gstrings,unsigned n_strings)1429 static struct usb_gadget_string_container *copy_gadget_strings(
1430 		struct usb_gadget_strings **sp, unsigned n_gstrings,
1431 		unsigned n_strings)
1432 {
1433 	struct usb_gadget_string_container *uc;
1434 	struct usb_gadget_strings **gs_array;
1435 	struct usb_gadget_strings *gs;
1436 	struct usb_string *s;
1437 	unsigned mem;
1438 	unsigned n_gs;
1439 	unsigned n_s;
1440 	void *stash;
1441 
1442 	mem = sizeof(*uc);
1443 	mem += sizeof(void *) * (n_gstrings + 1);
1444 	mem += sizeof(struct usb_gadget_strings) * n_gstrings;
1445 	mem += sizeof(struct usb_string) * (n_strings + 1) * (n_gstrings);
1446 	uc = kmalloc(mem, GFP_KERNEL);
1447 	if (!uc)
1448 		return ERR_PTR(-ENOMEM);
1449 	gs_array = get_containers_gs(uc);
1450 	stash = uc->stash;
1451 	stash += sizeof(void *) * (n_gstrings + 1);
1452 	for (n_gs = 0; n_gs < n_gstrings; n_gs++) {
1453 		struct usb_string *org_s;
1454 
1455 		gs_array[n_gs] = stash;
1456 		gs = gs_array[n_gs];
1457 		stash += sizeof(struct usb_gadget_strings);
1458 		gs->language = sp[n_gs]->language;
1459 		gs->strings = stash;
1460 		org_s = sp[n_gs]->strings;
1461 
1462 		for (n_s = 0; n_s < n_strings; n_s++) {
1463 			s = stash;
1464 			stash += sizeof(struct usb_string);
1465 			if (org_s->s)
1466 				s->s = org_s->s;
1467 			else
1468 				s->s = "";
1469 			org_s++;
1470 		}
1471 		s = stash;
1472 		s->s = NULL;
1473 		stash += sizeof(struct usb_string);
1474 
1475 	}
1476 	gs_array[n_gs] = NULL;
1477 	return uc;
1478 }
1479 
1480 /**
1481  * usb_gstrings_attach() - attach gadget strings to a cdev and assign ids
1482  * @cdev: the device whose string descriptor IDs are being allocated
1483  * and attached.
1484  * @sp: an array of usb_gadget_strings to attach.
1485  * @n_strings: number of entries in each usb_strings array (sp[]->strings)
1486  *
1487  * This function will create a deep copy of usb_gadget_strings and usb_string
1488  * and attach it to the cdev. The actual string (usb_string.s) will not be
1489  * copied but only a referenced will be made. The struct usb_gadget_strings
1490  * array may contain multiple languages and should be NULL terminated.
1491  * The ->language pointer of each struct usb_gadget_strings has to contain the
1492  * same amount of entries.
1493  * For instance: sp[0] is en-US, sp[1] is es-ES. It is expected that the first
1494  * usb_string entry of es-ES contains the translation of the first usb_string
1495  * entry of en-US. Therefore both entries become the same id assign.
1496  */
usb_gstrings_attach(struct usb_composite_dev * cdev,struct usb_gadget_strings ** sp,unsigned n_strings)1497 struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
1498 		struct usb_gadget_strings **sp, unsigned n_strings)
1499 {
1500 	struct usb_gadget_string_container *uc;
1501 	struct usb_gadget_strings **n_gs;
1502 	unsigned n_gstrings = 0;
1503 	unsigned i;
1504 	int ret;
1505 
1506 	for (i = 0; sp[i]; i++)
1507 		n_gstrings++;
1508 
1509 	if (!n_gstrings)
1510 		return ERR_PTR(-EINVAL);
1511 
1512 	uc = copy_gadget_strings(sp, n_gstrings, n_strings);
1513 	if (IS_ERR(uc))
1514 		return ERR_CAST(uc);
1515 
1516 	n_gs = get_containers_gs(uc);
1517 	ret = usb_string_ids_tab(cdev, n_gs[0]->strings);
1518 	if (ret)
1519 		goto err;
1520 
1521 	for (i = 1; i < n_gstrings; i++) {
1522 		struct usb_string *m_s;
1523 		struct usb_string *s;
1524 		unsigned n;
1525 
1526 		m_s = n_gs[0]->strings;
1527 		s = n_gs[i]->strings;
1528 		for (n = 0; n < n_strings; n++) {
1529 			s->id = m_s->id;
1530 			s++;
1531 			m_s++;
1532 		}
1533 	}
1534 	list_add_tail(&uc->list, &cdev->gstrings);
1535 	return n_gs[0]->strings;
1536 err:
1537 	kfree(uc);
1538 	return ERR_PTR(ret);
1539 }
1540 EXPORT_SYMBOL_GPL(usb_gstrings_attach);
1541 
1542 /**
1543  * usb_string_ids_n() - allocate unused string IDs in batch
1544  * @c: the device whose string descriptor IDs are being allocated
1545  * @n: number of string IDs to allocate
1546  * Context: single threaded during gadget setup
1547  *
1548  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1549  * valid IDs.  At least provided that @n is non-zero because if it
1550  * is, returns last requested ID which is now very useful information.
1551  *
1552  * @usb_string_ids_n() is called from bind() callbacks to allocate
1553  * string IDs.  Drivers for functions, configurations, or gadgets will
1554  * then store that ID in the appropriate descriptors and string table.
1555  *
1556  * All string identifier should be allocated using this,
1557  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1558  * example different functions don't wrongly assign different meanings
1559  * to the same identifier.
1560  */
usb_string_ids_n(struct usb_composite_dev * c,unsigned n)1561 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1562 {
1563 	unsigned next = c->next_string_id;
1564 	if (unlikely(n > 254 || (unsigned)next + n > 254))
1565 		return -ENODEV;
1566 	c->next_string_id += n;
1567 	return next + 1;
1568 }
1569 EXPORT_SYMBOL_GPL(usb_string_ids_n);
1570 
1571 /*-------------------------------------------------------------------------*/
1572 
composite_setup_complete(struct usb_ep * ep,struct usb_request * req)1573 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1574 {
1575 	struct usb_composite_dev *cdev;
1576 
1577 	if (req->status || req->actual != req->length)
1578 		DBG((struct usb_composite_dev *) ep->driver_data,
1579 				"setup complete --> %d, %d/%d\n",
1580 				req->status, req->actual, req->length);
1581 
1582 	/*
1583 	 * REVIST The same ep0 requests are shared with function drivers
1584 	 * so they don't have to maintain the same ->complete() stubs.
1585 	 *
1586 	 * Because of that, we need to check for the validity of ->context
1587 	 * here, even though we know we've set it to something useful.
1588 	 */
1589 	if (!req->context)
1590 		return;
1591 
1592 	cdev = req->context;
1593 
1594 	if (cdev->req == req)
1595 		cdev->setup_pending = false;
1596 	else if (cdev->os_desc_req == req)
1597 		cdev->os_desc_pending = false;
1598 	else
1599 		WARN(1, "unknown request %p\n", req);
1600 }
1601 
composite_ep0_queue(struct usb_composite_dev * cdev,struct usb_request * req,gfp_t gfp_flags)1602 static int composite_ep0_queue(struct usb_composite_dev *cdev,
1603 		struct usb_request *req, gfp_t gfp_flags)
1604 {
1605 	int ret;
1606 
1607 	ret = usb_ep_queue(cdev->gadget->ep0, req, gfp_flags);
1608 	if (ret == 0) {
1609 		if (cdev->req == req)
1610 			cdev->setup_pending = true;
1611 		else if (cdev->os_desc_req == req)
1612 			cdev->os_desc_pending = true;
1613 		else
1614 			WARN(1, "unknown request %p\n", req);
1615 	}
1616 
1617 	return ret;
1618 }
1619 
count_ext_compat(struct usb_configuration * c)1620 static int count_ext_compat(struct usb_configuration *c)
1621 {
1622 	int i, res;
1623 
1624 	res = 0;
1625 	for (i = 0; i < c->next_interface_id; ++i) {
1626 		struct usb_function *f;
1627 		int j;
1628 
1629 		f = c->interface[i];
1630 		for (j = 0; j < f->os_desc_n; ++j) {
1631 			struct usb_os_desc *d;
1632 
1633 			if (i != f->os_desc_table[j].if_id)
1634 				continue;
1635 			d = f->os_desc_table[j].os_desc;
1636 			if (d && d->ext_compat_id)
1637 				++res;
1638 		}
1639 	}
1640 	BUG_ON(res > 255);
1641 	return res;
1642 }
1643 
fill_ext_compat(struct usb_configuration * c,u8 * buf)1644 static int fill_ext_compat(struct usb_configuration *c, u8 *buf)
1645 {
1646 	int i, count;
1647 
1648 	count = 16;
1649 	buf += 16;
1650 	for (i = 0; i < c->next_interface_id; ++i) {
1651 		struct usb_function *f;
1652 		int j;
1653 
1654 		f = c->interface[i];
1655 		for (j = 0; j < f->os_desc_n; ++j) {
1656 			struct usb_os_desc *d;
1657 
1658 			if (i != f->os_desc_table[j].if_id)
1659 				continue;
1660 			d = f->os_desc_table[j].os_desc;
1661 			if (d && d->ext_compat_id) {
1662 				*buf++ = i;
1663 				*buf++ = 0x01;
1664 				memcpy(buf, d->ext_compat_id, 16);
1665 				buf += 22;
1666 			} else {
1667 				++buf;
1668 				*buf = 0x01;
1669 				buf += 23;
1670 			}
1671 			count += 24;
1672 			if (count + 24 >= USB_COMP_EP0_OS_DESC_BUFSIZ)
1673 				return count;
1674 		}
1675 	}
1676 
1677 	return count;
1678 }
1679 
count_ext_prop(struct usb_configuration * c,int interface)1680 static int count_ext_prop(struct usb_configuration *c, int interface)
1681 {
1682 	struct usb_function *f;
1683 	int j;
1684 
1685 	f = c->interface[interface];
1686 	for (j = 0; j < f->os_desc_n; ++j) {
1687 		struct usb_os_desc *d;
1688 
1689 		if (interface != f->os_desc_table[j].if_id)
1690 			continue;
1691 		d = f->os_desc_table[j].os_desc;
1692 		if (d && d->ext_compat_id)
1693 			return d->ext_prop_count;
1694 	}
1695 	return 0;
1696 }
1697 
len_ext_prop(struct usb_configuration * c,int interface)1698 static int len_ext_prop(struct usb_configuration *c, int interface)
1699 {
1700 	struct usb_function *f;
1701 	struct usb_os_desc *d;
1702 	int j, res;
1703 
1704 	res = 10; /* header length */
1705 	f = c->interface[interface];
1706 	for (j = 0; j < f->os_desc_n; ++j) {
1707 		if (interface != f->os_desc_table[j].if_id)
1708 			continue;
1709 		d = f->os_desc_table[j].os_desc;
1710 		if (d)
1711 			return min(res + d->ext_prop_len, 4096);
1712 	}
1713 	return res;
1714 }
1715 
fill_ext_prop(struct usb_configuration * c,int interface,u8 * buf)1716 static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
1717 {
1718 	struct usb_function *f;
1719 	struct usb_os_desc *d;
1720 	struct usb_os_desc_ext_prop *ext_prop;
1721 	int j, count, n, ret;
1722 
1723 	f = c->interface[interface];
1724 	count = 10; /* header length */
1725 	buf += 10;
1726 	for (j = 0; j < f->os_desc_n; ++j) {
1727 		if (interface != f->os_desc_table[j].if_id)
1728 			continue;
1729 		d = f->os_desc_table[j].os_desc;
1730 		if (d)
1731 			list_for_each_entry(ext_prop, &d->ext_prop, entry) {
1732 				n = ext_prop->data_len +
1733 					ext_prop->name_len + 14;
1734 				if (count + n >= USB_COMP_EP0_OS_DESC_BUFSIZ)
1735 					return count;
1736 				usb_ext_prop_put_size(buf, n);
1737 				usb_ext_prop_put_type(buf, ext_prop->type);
1738 				ret = usb_ext_prop_put_name(buf, ext_prop->name,
1739 							    ext_prop->name_len);
1740 				if (ret < 0)
1741 					return ret;
1742 				switch (ext_prop->type) {
1743 				case USB_EXT_PROP_UNICODE:
1744 				case USB_EXT_PROP_UNICODE_ENV:
1745 				case USB_EXT_PROP_UNICODE_LINK:
1746 					usb_ext_prop_put_unicode(buf, ret,
1747 							 ext_prop->data,
1748 							 ext_prop->data_len);
1749 					break;
1750 				case USB_EXT_PROP_BINARY:
1751 					usb_ext_prop_put_binary(buf, ret,
1752 							ext_prop->data,
1753 							ext_prop->data_len);
1754 					break;
1755 				case USB_EXT_PROP_LE32:
1756 					/* not implemented */
1757 				case USB_EXT_PROP_BE32:
1758 					/* not implemented */
1759 				default:
1760 					return -EINVAL;
1761 				}
1762 				buf += n;
1763 				count += n;
1764 			}
1765 	}
1766 
1767 	return count;
1768 }
1769 
1770 /*
1771  * The setup() callback implements all the ep0 functionality that's
1772  * not handled lower down, in hardware or the hardware driver(like
1773  * device and endpoint feature flags, and their status).  It's all
1774  * housekeeping for the gadget function we're implementing.  Most of
1775  * the work is in config and function specific setup.
1776  */
1777 int
composite_setup(struct usb_gadget * gadget,const struct usb_ctrlrequest * ctrl)1778 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1779 {
1780 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
1781 	struct usb_request		*req = cdev->req;
1782 	int				value = -EOPNOTSUPP;
1783 	int				status = 0;
1784 	u16				w_index = le16_to_cpu(ctrl->wIndex);
1785 	u8				intf = w_index & 0xFF;
1786 	u16				w_value = le16_to_cpu(ctrl->wValue);
1787 	u16				w_length = le16_to_cpu(ctrl->wLength);
1788 	struct usb_function		*f = NULL;
1789 	struct usb_function		*iter;
1790 	u8				endp;
1791 
1792 	if (w_length > USB_COMP_EP0_BUFSIZ) {
1793 		if (ctrl->bRequestType & USB_DIR_IN) {
1794 			/* Cast away the const, we are going to overwrite on purpose. */
1795 			__le16 *temp = (__le16 *)&ctrl->wLength;
1796 
1797 			*temp = cpu_to_le16(USB_COMP_EP0_BUFSIZ);
1798 			w_length = USB_COMP_EP0_BUFSIZ;
1799 		} else {
1800 			goto done;
1801 		}
1802 	}
1803 
1804 	/* partial re-init of the response message; the function or the
1805 	 * gadget might need to intercept e.g. a control-OUT completion
1806 	 * when we delegate to it.
1807 	 */
1808 	req->zero = 0;
1809 	req->context = cdev;
1810 	req->complete = composite_setup_complete;
1811 	req->length = 0;
1812 	gadget->ep0->driver_data = cdev;
1813 
1814 	/*
1815 	 * Don't let non-standard requests match any of the cases below
1816 	 * by accident.
1817 	 */
1818 	if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
1819 		goto unknown;
1820 
1821 	switch (ctrl->bRequest) {
1822 
1823 	/* we handle all standard USB descriptors */
1824 	case USB_REQ_GET_DESCRIPTOR:
1825 		if (ctrl->bRequestType != USB_DIR_IN)
1826 			goto unknown;
1827 		switch (w_value >> 8) {
1828 
1829 		case USB_DT_DEVICE:
1830 			cdev->desc.bNumConfigurations =
1831 				count_configs(cdev, USB_DT_DEVICE);
1832 			cdev->desc.bMaxPacketSize0 =
1833 				cdev->gadget->ep0->maxpacket;
1834 			if (gadget_is_superspeed(gadget)) {
1835 				if (gadget->speed >= USB_SPEED_SUPER) {
1836 					cdev->desc.bcdUSB = cpu_to_le16(0x0320);
1837 					cdev->desc.bMaxPacketSize0 = 9;
1838 				} else {
1839 					cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1840 				}
1841 			} else {
1842 				if (gadget->lpm_capable || cdev->use_webusb)
1843 					cdev->desc.bcdUSB = cpu_to_le16(0x0201);
1844 				else
1845 					cdev->desc.bcdUSB = cpu_to_le16(0x0200);
1846 			}
1847 
1848 			value = min_t(u16, w_length, sizeof(cdev->desc));
1849 			memcpy(req->buf, &cdev->desc, value);
1850 			break;
1851 		case USB_DT_DEVICE_QUALIFIER:
1852 			if (!gadget_is_dualspeed(gadget) ||
1853 			    gadget->speed >= USB_SPEED_SUPER)
1854 				break;
1855 			device_qual(cdev);
1856 			value = min_t(int, w_length,
1857 				sizeof(struct usb_qualifier_descriptor));
1858 			break;
1859 		case USB_DT_OTHER_SPEED_CONFIG:
1860 			if (!gadget_is_dualspeed(gadget) ||
1861 			    gadget->speed >= USB_SPEED_SUPER)
1862 				break;
1863 			fallthrough;
1864 		case USB_DT_CONFIG:
1865 			value = config_desc(cdev, w_value);
1866 			if (value >= 0)
1867 				value = min_t(u16, w_length, value);
1868 			break;
1869 		case USB_DT_STRING:
1870 			value = get_string(cdev, req->buf,
1871 					w_index, w_value & 0xff);
1872 			if (value >= 0)
1873 				value = min_t(u16, w_length, value);
1874 			break;
1875 		case USB_DT_BOS:
1876 			if (gadget_is_superspeed(gadget) ||
1877 			    gadget->lpm_capable || cdev->use_webusb) {
1878 				value = bos_desc(cdev);
1879 				value = min_t(u16, w_length, value);
1880 			}
1881 			break;
1882 		case USB_DT_OTG:
1883 			if (gadget_is_otg(gadget)) {
1884 				struct usb_configuration *config;
1885 				int otg_desc_len = 0;
1886 
1887 				if (cdev->config)
1888 					config = cdev->config;
1889 				else
1890 					config = list_first_entry(
1891 							&cdev->configs,
1892 						struct usb_configuration, list);
1893 				if (!config)
1894 					goto done;
1895 
1896 				if (gadget->otg_caps &&
1897 					(gadget->otg_caps->otg_rev >= 0x0200))
1898 					otg_desc_len += sizeof(
1899 						struct usb_otg20_descriptor);
1900 				else
1901 					otg_desc_len += sizeof(
1902 						struct usb_otg_descriptor);
1903 
1904 				value = min_t(int, w_length, otg_desc_len);
1905 				memcpy(req->buf, config->descriptors[0], value);
1906 			}
1907 			break;
1908 		}
1909 		break;
1910 
1911 	/* any number of configs can work */
1912 	case USB_REQ_SET_CONFIGURATION:
1913 		if (ctrl->bRequestType != 0)
1914 			goto unknown;
1915 		if (gadget_is_otg(gadget)) {
1916 			if (gadget->a_hnp_support)
1917 				DBG(cdev, "HNP available\n");
1918 			else if (gadget->a_alt_hnp_support)
1919 				DBG(cdev, "HNP on another port\n");
1920 			else
1921 				VDBG(cdev, "HNP inactive\n");
1922 		}
1923 		spin_lock(&cdev->lock);
1924 		value = set_config(cdev, ctrl, w_value);
1925 		spin_unlock(&cdev->lock);
1926 		break;
1927 	case USB_REQ_GET_CONFIGURATION:
1928 		if (ctrl->bRequestType != USB_DIR_IN)
1929 			goto unknown;
1930 		if (cdev->config)
1931 			*(u8 *)req->buf = cdev->config->bConfigurationValue;
1932 		else
1933 			*(u8 *)req->buf = 0;
1934 		value = min_t(u16, w_length, 1);
1935 		break;
1936 
1937 	/* function drivers must handle get/set altsetting */
1938 	case USB_REQ_SET_INTERFACE:
1939 		if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1940 			goto unknown;
1941 		if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1942 			break;
1943 		f = cdev->config->interface[intf];
1944 		if (!f)
1945 			break;
1946 
1947 		/*
1948 		 * If there's no get_alt() method, we know only altsetting zero
1949 		 * works. There is no need to check if set_alt() is not NULL
1950 		 * as we check this in usb_add_function().
1951 		 */
1952 		if (w_value && !f->get_alt)
1953 			break;
1954 
1955 		spin_lock(&cdev->lock);
1956 		value = f->set_alt(f, w_index, w_value);
1957 		if (value == USB_GADGET_DELAYED_STATUS) {
1958 			DBG(cdev,
1959 			 "%s: interface %d (%s) requested delayed status\n",
1960 					__func__, intf, f->name);
1961 			cdev->delayed_status++;
1962 			DBG(cdev, "delayed_status count %d\n",
1963 					cdev->delayed_status);
1964 		}
1965 		spin_unlock(&cdev->lock);
1966 		break;
1967 	case USB_REQ_GET_INTERFACE:
1968 		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1969 			goto unknown;
1970 		if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1971 			break;
1972 		f = cdev->config->interface[intf];
1973 		if (!f)
1974 			break;
1975 		/* lots of interfaces only need altsetting zero... */
1976 		value = f->get_alt ? f->get_alt(f, w_index) : 0;
1977 		if (value < 0)
1978 			break;
1979 		*((u8 *)req->buf) = value;
1980 		value = min_t(u16, w_length, 1);
1981 		break;
1982 	case USB_REQ_GET_STATUS:
1983 		if (gadget_is_otg(gadget) && gadget->hnp_polling_support &&
1984 						(w_index == OTG_STS_SELECTOR)) {
1985 			if (ctrl->bRequestType != (USB_DIR_IN |
1986 							USB_RECIP_DEVICE))
1987 				goto unknown;
1988 			*((u8 *)req->buf) = gadget->host_request_flag;
1989 			value = 1;
1990 			break;
1991 		}
1992 
1993 		/*
1994 		 * USB 3.0 additions:
1995 		 * Function driver should handle get_status request. If such cb
1996 		 * wasn't supplied we respond with default value = 0
1997 		 * Note: function driver should supply such cb only for the
1998 		 * first interface of the function
1999 		 */
2000 		if (!gadget_is_superspeed(gadget))
2001 			goto unknown;
2002 		if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
2003 			goto unknown;
2004 		value = 2;	/* This is the length of the get_status reply */
2005 		put_unaligned_le16(0, req->buf);
2006 		if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
2007 			break;
2008 		f = cdev->config->interface[intf];
2009 		if (!f)
2010 			break;
2011 
2012 		if (f->get_status) {
2013 			status = f->get_status(f);
2014 			if (status < 0)
2015 				break;
2016 		} else {
2017 			/* Set D0 and D1 bits based on func wakeup capability */
2018 			if (f->config->bmAttributes & USB_CONFIG_ATT_WAKEUP) {
2019 				status |= USB_INTRF_STAT_FUNC_RW_CAP;
2020 				if (f->func_wakeup_armed)
2021 					status |= USB_INTRF_STAT_FUNC_RW;
2022 			}
2023 		}
2024 
2025 		put_unaligned_le16(status & 0x0000ffff, req->buf);
2026 		break;
2027 	/*
2028 	 * Function drivers should handle SetFeature/ClearFeature
2029 	 * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
2030 	 * only for the first interface of the function
2031 	 */
2032 	case USB_REQ_CLEAR_FEATURE:
2033 	case USB_REQ_SET_FEATURE:
2034 		if (!gadget_is_superspeed(gadget))
2035 			goto unknown;
2036 		if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
2037 			goto unknown;
2038 		switch (w_value) {
2039 		case USB_INTRF_FUNC_SUSPEND:
2040 			if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
2041 				break;
2042 			f = cdev->config->interface[intf];
2043 			if (!f)
2044 				break;
2045 			value = 0;
2046 			if (f->func_suspend) {
2047 				value = f->func_suspend(f, w_index >> 8);
2048 			/* SetFeature(FUNCTION_SUSPEND) */
2049 			} else if (ctrl->bRequest == USB_REQ_SET_FEATURE) {
2050 				if (!(f->config->bmAttributes &
2051 				      USB_CONFIG_ATT_WAKEUP) &&
2052 				     (w_index & USB_INTRF_FUNC_SUSPEND_RW))
2053 					break;
2054 
2055 				f->func_wakeup_armed = !!(w_index &
2056 							  USB_INTRF_FUNC_SUSPEND_RW);
2057 
2058 				if (w_index & USB_INTRF_FUNC_SUSPEND_LP) {
2059 					if (f->suspend && !f->func_suspended) {
2060 						f->suspend(f);
2061 						f->func_suspended = true;
2062 					}
2063 				/*
2064 				 * Handle cases where host sends function resume
2065 				 * through SetFeature(FUNCTION_SUSPEND) but low power
2066 				 * bit reset
2067 				 */
2068 				} else {
2069 					if (f->resume && f->func_suspended) {
2070 						f->resume(f);
2071 						f->func_suspended = false;
2072 					}
2073 				}
2074 			/* ClearFeature(FUNCTION_SUSPEND) */
2075 			} else if (ctrl->bRequest == USB_REQ_CLEAR_FEATURE) {
2076 				f->func_wakeup_armed = false;
2077 
2078 				if (f->resume && f->func_suspended) {
2079 					f->resume(f);
2080 					f->func_suspended = false;
2081 				}
2082 			}
2083 
2084 			if (value < 0) {
2085 				ERROR(cdev,
2086 				      "func_suspend() returned error %d\n",
2087 				      value);
2088 				value = 0;
2089 			}
2090 			break;
2091 		}
2092 		break;
2093 	default:
2094 unknown:
2095 		/*
2096 		 * OS descriptors handling
2097 		 */
2098 		if (cdev->use_os_string && cdev->os_desc_config &&
2099 		    (ctrl->bRequestType & USB_TYPE_VENDOR) &&
2100 		    ctrl->bRequest == cdev->b_vendor_code) {
2101 			struct usb_configuration	*os_desc_cfg;
2102 			u8				*buf;
2103 			int				interface;
2104 			int				count = 0;
2105 
2106 			req = cdev->os_desc_req;
2107 			req->context = cdev;
2108 			req->complete = composite_setup_complete;
2109 			buf = req->buf;
2110 			os_desc_cfg = cdev->os_desc_config;
2111 			w_length = min_t(u16, w_length, USB_COMP_EP0_OS_DESC_BUFSIZ);
2112 			memset(buf, 0, w_length);
2113 			buf[5] = 0x01;
2114 			switch (ctrl->bRequestType & USB_RECIP_MASK) {
2115 			/*
2116 			 * The Microsoft CompatID OS Descriptor Spec(w_index = 0x4) and
2117 			 * Extended Prop OS Desc Spec(w_index = 0x5) state that the
2118 			 * HighByte of wValue is the InterfaceNumber and the LowByte is
2119 			 * the PageNumber. This high/low byte ordering is incorrectly
2120 			 * documented in the Spec. USB analyzer output on the below
2121 			 * request packets show the high/low byte inverted i.e LowByte
2122 			 * is the InterfaceNumber and the HighByte is the PageNumber.
2123 			 * Since we dont support >64KB CompatID/ExtendedProp descriptors,
2124 			 * PageNumber is set to 0. Hence verify that the HighByte is 0
2125 			 * for below two cases.
2126 			 */
2127 			case USB_RECIP_DEVICE:
2128 				if (w_index != 0x4 || (w_value >> 8))
2129 					break;
2130 				buf[6] = w_index;
2131 				/* Number of ext compat interfaces */
2132 				count = count_ext_compat(os_desc_cfg);
2133 				buf[8] = count;
2134 				count *= 24; /* 24 B/ext compat desc */
2135 				count += 16; /* header */
2136 				put_unaligned_le32(count, buf);
2137 				value = w_length;
2138 				if (w_length > 0x10) {
2139 					value = fill_ext_compat(os_desc_cfg, buf);
2140 					value = min_t(u16, w_length, value);
2141 				}
2142 				break;
2143 			case USB_RECIP_INTERFACE:
2144 				if (w_index != 0x5 || (w_value >> 8))
2145 					break;
2146 				interface = w_value & 0xFF;
2147 				if (interface >= MAX_CONFIG_INTERFACES ||
2148 				    !os_desc_cfg->interface[interface])
2149 					break;
2150 				buf[6] = w_index;
2151 				count = count_ext_prop(os_desc_cfg,
2152 					interface);
2153 				put_unaligned_le16(count, buf + 8);
2154 				count = len_ext_prop(os_desc_cfg,
2155 					interface);
2156 				put_unaligned_le32(count, buf);
2157 				value = w_length;
2158 				if (w_length > 0x0A) {
2159 					value = fill_ext_prop(os_desc_cfg,
2160 							      interface, buf);
2161 					if (value >= 0)
2162 						value = min_t(u16, w_length, value);
2163 				}
2164 				break;
2165 			}
2166 
2167 			goto check_value;
2168 		}
2169 
2170 		/*
2171 		 * WebUSB URL descriptor handling, following:
2172 		 * https://wicg.github.io/webusb/#device-requests
2173 		 */
2174 		if (cdev->use_webusb &&
2175 		    ctrl->bRequestType == (USB_DIR_IN | USB_TYPE_VENDOR) &&
2176 		    w_index == WEBUSB_GET_URL &&
2177 		    w_value == WEBUSB_LANDING_PAGE_PRESENT &&
2178 		    ctrl->bRequest == cdev->b_webusb_vendor_code) {
2179 			unsigned int	landing_page_length;
2180 			unsigned int	landing_page_offset;
2181 			struct webusb_url_descriptor *url_descriptor =
2182 					(struct webusb_url_descriptor *)cdev->req->buf;
2183 
2184 			url_descriptor->bDescriptorType = WEBUSB_URL_DESCRIPTOR_TYPE;
2185 
2186 			if (strncasecmp(cdev->landing_page, "https://",  8) == 0) {
2187 				landing_page_offset = 8;
2188 				url_descriptor->bScheme = WEBUSB_URL_SCHEME_HTTPS;
2189 			} else if (strncasecmp(cdev->landing_page, "http://", 7) == 0) {
2190 				landing_page_offset = 7;
2191 				url_descriptor->bScheme = WEBUSB_URL_SCHEME_HTTP;
2192 			} else {
2193 				landing_page_offset = 0;
2194 				url_descriptor->bScheme = WEBUSB_URL_SCHEME_NONE;
2195 			}
2196 
2197 			landing_page_length = strnlen(cdev->landing_page,
2198 				sizeof(url_descriptor->URL)
2199 				- WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + landing_page_offset);
2200 
2201 			if (w_length < WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + landing_page_length)
2202 				landing_page_length = w_length
2203 				- WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + landing_page_offset;
2204 
2205 			memcpy(url_descriptor->URL,
2206 				cdev->landing_page + landing_page_offset,
2207 				landing_page_length - landing_page_offset);
2208 			url_descriptor->bLength = landing_page_length
2209 				- landing_page_offset + WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH;
2210 
2211 			value = url_descriptor->bLength;
2212 
2213 			goto check_value;
2214 		}
2215 
2216 		VDBG(cdev,
2217 			"non-core control req%02x.%02x v%04x i%04x l%d\n",
2218 			ctrl->bRequestType, ctrl->bRequest,
2219 			w_value, w_index, w_length);
2220 
2221 		/* functions always handle their interfaces and endpoints...
2222 		 * punt other recipients (other, WUSB, ...) to the current
2223 		 * configuration code.
2224 		 */
2225 		if (cdev->config) {
2226 			list_for_each_entry(f, &cdev->config->functions, list)
2227 				if (f->req_match &&
2228 				    f->req_match(f, ctrl, false))
2229 					goto try_fun_setup;
2230 		} else {
2231 			struct usb_configuration *c;
2232 			list_for_each_entry(c, &cdev->configs, list)
2233 				list_for_each_entry(f, &c->functions, list)
2234 					if (f->req_match &&
2235 					    f->req_match(f, ctrl, true))
2236 						goto try_fun_setup;
2237 		}
2238 		f = NULL;
2239 
2240 		switch (ctrl->bRequestType & USB_RECIP_MASK) {
2241 		case USB_RECIP_INTERFACE:
2242 			if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
2243 				break;
2244 			f = cdev->config->interface[intf];
2245 			break;
2246 
2247 		case USB_RECIP_ENDPOINT:
2248 			if (!cdev->config)
2249 				break;
2250 			endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
2251 			list_for_each_entry(iter, &cdev->config->functions, list) {
2252 				if (test_bit(endp, iter->endpoints)) {
2253 					f = iter;
2254 					break;
2255 				}
2256 			}
2257 			break;
2258 		}
2259 try_fun_setup:
2260 		if (f && f->setup)
2261 			value = f->setup(f, ctrl);
2262 		else {
2263 			struct usb_configuration	*c;
2264 
2265 			c = cdev->config;
2266 			if (!c)
2267 				goto done;
2268 
2269 			/* try current config's setup */
2270 			if (c->setup) {
2271 				value = c->setup(c, ctrl);
2272 				goto done;
2273 			}
2274 
2275 			/* try the only function in the current config */
2276 			if (!list_is_singular(&c->functions))
2277 				goto done;
2278 			f = list_first_entry(&c->functions, struct usb_function,
2279 					     list);
2280 			if (f->setup)
2281 				value = f->setup(f, ctrl);
2282 		}
2283 
2284 		goto done;
2285 	}
2286 
2287 check_value:
2288 	/* respond with data transfer before status phase? */
2289 	if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
2290 		req->length = value;
2291 		req->context = cdev;
2292 		req->zero = value < w_length;
2293 		value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
2294 		if (value < 0) {
2295 			DBG(cdev, "ep_queue --> %d\n", value);
2296 			req->status = 0;
2297 			composite_setup_complete(gadget->ep0, req);
2298 		}
2299 	} else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
2300 		WARN(cdev,
2301 			"%s: Delayed status not supported for w_length != 0",
2302 			__func__);
2303 	}
2304 
2305 done:
2306 	/* device either stalls (value < 0) or reports success */
2307 	return value;
2308 }
2309 
__composite_disconnect(struct usb_gadget * gadget)2310 static void __composite_disconnect(struct usb_gadget *gadget)
2311 {
2312 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
2313 	unsigned long			flags;
2314 
2315 	/* REVISIT:  should we have config and device level
2316 	 * disconnect callbacks?
2317 	 */
2318 	spin_lock_irqsave(&cdev->lock, flags);
2319 	cdev->suspended = 0;
2320 	if (cdev->config)
2321 		reset_config(cdev);
2322 	if (cdev->driver->disconnect)
2323 		cdev->driver->disconnect(cdev);
2324 	spin_unlock_irqrestore(&cdev->lock, flags);
2325 }
2326 
composite_disconnect(struct usb_gadget * gadget)2327 void composite_disconnect(struct usb_gadget *gadget)
2328 {
2329 	usb_gadget_vbus_draw(gadget, 0);
2330 	__composite_disconnect(gadget);
2331 }
2332 
composite_reset(struct usb_gadget * gadget)2333 void composite_reset(struct usb_gadget *gadget)
2334 {
2335 	/*
2336 	 * Section 1.4.13 Standard Downstream Port of the USB battery charging
2337 	 * specification v1.2 states that a device connected on a SDP shall only
2338 	 * draw at max 100mA while in a connected, but unconfigured state.
2339 	 */
2340 	usb_gadget_vbus_draw(gadget, 100);
2341 	__composite_disconnect(gadget);
2342 }
2343 
2344 /*-------------------------------------------------------------------------*/
2345 
suspended_show(struct device * dev,struct device_attribute * attr,char * buf)2346 static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
2347 			      char *buf)
2348 {
2349 	struct usb_gadget *gadget = dev_to_usb_gadget(dev);
2350 	struct usb_composite_dev *cdev = get_gadget_data(gadget);
2351 
2352 	return sprintf(buf, "%d\n", cdev->suspended);
2353 }
2354 static DEVICE_ATTR_RO(suspended);
2355 
__composite_unbind(struct usb_gadget * gadget,bool unbind_driver)2356 static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
2357 {
2358 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
2359 	struct usb_gadget_strings	*gstr = cdev->driver->strings[0];
2360 	struct usb_string		*dev_str = gstr->strings;
2361 
2362 	/* composite_disconnect() must already have been called
2363 	 * by the underlying peripheral controller driver!
2364 	 * so there's no i/o concurrency that could affect the
2365 	 * state protected by cdev->lock.
2366 	 */
2367 	WARN_ON(cdev->config);
2368 
2369 	while (!list_empty(&cdev->configs)) {
2370 		struct usb_configuration	*c;
2371 		c = list_first_entry(&cdev->configs,
2372 				struct usb_configuration, list);
2373 		remove_config(cdev, c);
2374 	}
2375 	if (cdev->driver->unbind && unbind_driver)
2376 		cdev->driver->unbind(cdev);
2377 
2378 	composite_dev_cleanup(cdev);
2379 
2380 	if (dev_str[USB_GADGET_MANUFACTURER_IDX].s == cdev->def_manufacturer)
2381 		dev_str[USB_GADGET_MANUFACTURER_IDX].s = "";
2382 
2383 	kfree(cdev->def_manufacturer);
2384 	kfree(cdev);
2385 	set_gadget_data(gadget, NULL);
2386 }
2387 
composite_unbind(struct usb_gadget * gadget)2388 static void composite_unbind(struct usb_gadget *gadget)
2389 {
2390 	__composite_unbind(gadget, true);
2391 }
2392 
update_unchanged_dev_desc(struct usb_device_descriptor * new,const struct usb_device_descriptor * old)2393 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
2394 		const struct usb_device_descriptor *old)
2395 {
2396 	__le16 idVendor;
2397 	__le16 idProduct;
2398 	__le16 bcdDevice;
2399 	u8 iSerialNumber;
2400 	u8 iManufacturer;
2401 	u8 iProduct;
2402 
2403 	/*
2404 	 * these variables may have been set in
2405 	 * usb_composite_overwrite_options()
2406 	 */
2407 	idVendor = new->idVendor;
2408 	idProduct = new->idProduct;
2409 	bcdDevice = new->bcdDevice;
2410 	iSerialNumber = new->iSerialNumber;
2411 	iManufacturer = new->iManufacturer;
2412 	iProduct = new->iProduct;
2413 
2414 	*new = *old;
2415 	if (idVendor)
2416 		new->idVendor = idVendor;
2417 	if (idProduct)
2418 		new->idProduct = idProduct;
2419 	if (bcdDevice)
2420 		new->bcdDevice = bcdDevice;
2421 	else
2422 		new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
2423 	if (iSerialNumber)
2424 		new->iSerialNumber = iSerialNumber;
2425 	if (iManufacturer)
2426 		new->iManufacturer = iManufacturer;
2427 	if (iProduct)
2428 		new->iProduct = iProduct;
2429 }
2430 
composite_dev_prepare(struct usb_composite_driver * composite,struct usb_composite_dev * cdev)2431 int composite_dev_prepare(struct usb_composite_driver *composite,
2432 		struct usb_composite_dev *cdev)
2433 {
2434 	struct usb_gadget *gadget = cdev->gadget;
2435 	int ret = -ENOMEM;
2436 
2437 	/* preallocate control response and buffer */
2438 	cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
2439 	if (!cdev->req)
2440 		return -ENOMEM;
2441 
2442 	cdev->req->buf = kzalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
2443 	if (!cdev->req->buf)
2444 		goto fail;
2445 
2446 	ret = device_create_file(&gadget->dev, &dev_attr_suspended);
2447 	if (ret)
2448 		goto fail_dev;
2449 
2450 	cdev->req->complete = composite_setup_complete;
2451 	cdev->req->context = cdev;
2452 	gadget->ep0->driver_data = cdev;
2453 
2454 	cdev->driver = composite;
2455 
2456 	/*
2457 	 * As per USB compliance update, a device that is actively drawing
2458 	 * more than 100mA from USB must report itself as bus-powered in
2459 	 * the GetStatus(DEVICE) call.
2460 	 */
2461 	if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
2462 		usb_gadget_set_selfpowered(gadget);
2463 
2464 	/* interface and string IDs start at zero via kzalloc.
2465 	 * we force endpoints to start unassigned; few controller
2466 	 * drivers will zero ep->driver_data.
2467 	 */
2468 	usb_ep_autoconfig_reset(gadget);
2469 	return 0;
2470 fail_dev:
2471 	kfree(cdev->req->buf);
2472 fail:
2473 	usb_ep_free_request(gadget->ep0, cdev->req);
2474 	cdev->req = NULL;
2475 	return ret;
2476 }
2477 
composite_os_desc_req_prepare(struct usb_composite_dev * cdev,struct usb_ep * ep0)2478 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
2479 				  struct usb_ep *ep0)
2480 {
2481 	int ret = 0;
2482 
2483 	cdev->os_desc_req = usb_ep_alloc_request(ep0, GFP_KERNEL);
2484 	if (!cdev->os_desc_req) {
2485 		ret = -ENOMEM;
2486 		goto end;
2487 	}
2488 
2489 	cdev->os_desc_req->buf = kmalloc(USB_COMP_EP0_OS_DESC_BUFSIZ,
2490 					 GFP_KERNEL);
2491 	if (!cdev->os_desc_req->buf) {
2492 		ret = -ENOMEM;
2493 		usb_ep_free_request(ep0, cdev->os_desc_req);
2494 		goto end;
2495 	}
2496 	cdev->os_desc_req->context = cdev;
2497 	cdev->os_desc_req->complete = composite_setup_complete;
2498 end:
2499 	return ret;
2500 }
2501 
composite_dev_cleanup(struct usb_composite_dev * cdev)2502 void composite_dev_cleanup(struct usb_composite_dev *cdev)
2503 {
2504 	struct usb_gadget_string_container *uc, *tmp;
2505 	struct usb_ep			   *ep, *tmp_ep;
2506 
2507 	list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
2508 		list_del(&uc->list);
2509 		kfree(uc);
2510 	}
2511 	if (cdev->os_desc_req) {
2512 		if (cdev->os_desc_pending)
2513 			usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req);
2514 
2515 		kfree(cdev->os_desc_req->buf);
2516 		cdev->os_desc_req->buf = NULL;
2517 		usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
2518 		cdev->os_desc_req = NULL;
2519 	}
2520 	if (cdev->req) {
2521 		if (cdev->setup_pending)
2522 			usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
2523 
2524 		kfree(cdev->req->buf);
2525 		cdev->req->buf = NULL;
2526 		usb_ep_free_request(cdev->gadget->ep0, cdev->req);
2527 		cdev->req = NULL;
2528 	}
2529 	cdev->next_string_id = 0;
2530 	device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
2531 
2532 	/*
2533 	 * Some UDC backends have a dynamic EP allocation scheme.
2534 	 *
2535 	 * In that case, the dispose() callback is used to notify the
2536 	 * backend that the EPs are no longer in use.
2537 	 *
2538 	 * Note: The UDC backend can remove the EP from the ep_list as
2539 	 *	 a result, so we need to use the _safe list iterator.
2540 	 */
2541 	list_for_each_entry_safe(ep, tmp_ep,
2542 				 &cdev->gadget->ep_list, ep_list) {
2543 		if (ep->ops->dispose)
2544 			ep->ops->dispose(ep);
2545 	}
2546 }
2547 
composite_bind(struct usb_gadget * gadget,struct usb_gadget_driver * gdriver)2548 static int composite_bind(struct usb_gadget *gadget,
2549 		struct usb_gadget_driver *gdriver)
2550 {
2551 	struct usb_composite_dev	*cdev;
2552 	struct usb_composite_driver	*composite = to_cdriver(gdriver);
2553 	int				status = -ENOMEM;
2554 
2555 	cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
2556 	if (!cdev)
2557 		return status;
2558 
2559 	spin_lock_init(&cdev->lock);
2560 	cdev->gadget = gadget;
2561 	set_gadget_data(gadget, cdev);
2562 	INIT_LIST_HEAD(&cdev->configs);
2563 	INIT_LIST_HEAD(&cdev->gstrings);
2564 
2565 	status = composite_dev_prepare(composite, cdev);
2566 	if (status)
2567 		goto fail;
2568 
2569 	/* composite gadget needs to assign strings for whole device (like
2570 	 * serial number), register function drivers, potentially update
2571 	 * power state and consumption, etc
2572 	 */
2573 	status = composite->bind(cdev);
2574 	if (status < 0)
2575 		goto fail;
2576 
2577 	if (cdev->use_os_string) {
2578 		status = composite_os_desc_req_prepare(cdev, gadget->ep0);
2579 		if (status)
2580 			goto fail;
2581 	}
2582 
2583 	update_unchanged_dev_desc(&cdev->desc, composite->dev);
2584 
2585 	/* has userspace failed to provide a serial number? */
2586 	if (composite->needs_serial && !cdev->desc.iSerialNumber)
2587 		WARNING(cdev, "userspace failed to provide iSerialNumber\n");
2588 
2589 	INFO(cdev, "%s ready\n", composite->name);
2590 	return 0;
2591 
2592 fail:
2593 	__composite_unbind(gadget, false);
2594 	return status;
2595 }
2596 
2597 /*-------------------------------------------------------------------------*/
2598 
composite_suspend(struct usb_gadget * gadget)2599 void composite_suspend(struct usb_gadget *gadget)
2600 {
2601 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
2602 	struct usb_function		*f;
2603 
2604 	/* REVISIT:  should we have config level
2605 	 * suspend/resume callbacks?
2606 	 */
2607 	DBG(cdev, "suspend\n");
2608 	if (cdev->config) {
2609 		list_for_each_entry(f, &cdev->config->functions, list) {
2610 			if (f->suspend)
2611 				f->suspend(f);
2612 		}
2613 	}
2614 	if (cdev->driver->suspend)
2615 		cdev->driver->suspend(cdev);
2616 
2617 	cdev->suspended = 1;
2618 
2619 	if (cdev->config &&
2620 	    cdev->config->bmAttributes & USB_CONFIG_ATT_SELFPOWER)
2621 		usb_gadget_set_selfpowered(gadget);
2622 
2623 	usb_gadget_vbus_draw(gadget, 2);
2624 }
2625 
composite_resume(struct usb_gadget * gadget)2626 void composite_resume(struct usb_gadget *gadget)
2627 {
2628 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
2629 	struct usb_function		*f;
2630 	unsigned			maxpower;
2631 
2632 	/* REVISIT:  should we have config level
2633 	 * suspend/resume callbacks?
2634 	 */
2635 	DBG(cdev, "resume\n");
2636 	if (cdev->driver->resume)
2637 		cdev->driver->resume(cdev);
2638 	if (cdev->config) {
2639 		list_for_each_entry(f, &cdev->config->functions, list) {
2640 			/*
2641 			 * Check for func_suspended flag to see if the function is
2642 			 * in USB3 FUNCTION_SUSPEND state. In this case resume is
2643 			 * done via FUNCTION_SUSPEND feature selector.
2644 			 */
2645 			if (f->resume && !f->func_suspended)
2646 				f->resume(f);
2647 		}
2648 
2649 		maxpower = cdev->config->MaxPower ?
2650 			cdev->config->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
2651 		if (gadget->speed < USB_SPEED_SUPER)
2652 			maxpower = min(maxpower, 500U);
2653 		else
2654 			maxpower = min(maxpower, 900U);
2655 
2656 		if (maxpower > USB_SELF_POWER_VBUS_MAX_DRAW ||
2657 		    !(cdev->config->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
2658 			usb_gadget_clear_selfpowered(gadget);
2659 		else
2660 			usb_gadget_set_selfpowered(gadget);
2661 
2662 		usb_gadget_vbus_draw(gadget, maxpower);
2663 	} else {
2664 		maxpower = CONFIG_USB_GADGET_VBUS_DRAW;
2665 		maxpower = min(maxpower, 100U);
2666 		usb_gadget_vbus_draw(gadget, maxpower);
2667 	}
2668 
2669 	cdev->suspended = 0;
2670 }
2671 
2672 /*-------------------------------------------------------------------------*/
2673 
2674 static const struct usb_gadget_driver composite_driver_template = {
2675 	.bind		= composite_bind,
2676 	.unbind		= composite_unbind,
2677 
2678 	.setup		= composite_setup,
2679 	.reset		= composite_reset,
2680 	.disconnect	= composite_disconnect,
2681 
2682 	.suspend	= composite_suspend,
2683 	.resume		= composite_resume,
2684 
2685 	.driver	= {
2686 		.owner		= THIS_MODULE,
2687 	},
2688 };
2689 
2690 /**
2691  * usb_composite_probe() - register a composite driver
2692  * @driver: the driver to register
2693  *
2694  * Context: single threaded during gadget setup
2695  *
2696  * This function is used to register drivers using the composite driver
2697  * framework.  The return value is zero, or a negative errno value.
2698  * Those values normally come from the driver's @bind method, which does
2699  * all the work of setting up the driver to match the hardware.
2700  *
2701  * On successful return, the gadget is ready to respond to requests from
2702  * the host, unless one of its components invokes usb_gadget_disconnect()
2703  * while it was binding.  That would usually be done in order to wait for
2704  * some userspace participation.
2705  */
usb_composite_probe(struct usb_composite_driver * driver)2706 int usb_composite_probe(struct usb_composite_driver *driver)
2707 {
2708 	struct usb_gadget_driver *gadget_driver;
2709 
2710 	if (!driver || !driver->dev || !driver->bind)
2711 		return -EINVAL;
2712 
2713 	if (!driver->name)
2714 		driver->name = "composite";
2715 
2716 	driver->gadget_driver = composite_driver_template;
2717 	gadget_driver = &driver->gadget_driver;
2718 
2719 	gadget_driver->function =  (char *) driver->name;
2720 	gadget_driver->driver.name = driver->name;
2721 	gadget_driver->max_speed = driver->max_speed;
2722 
2723 	return usb_gadget_register_driver(gadget_driver);
2724 }
2725 EXPORT_SYMBOL_GPL(usb_composite_probe);
2726 
2727 /**
2728  * usb_composite_unregister() - unregister a composite driver
2729  * @driver: the driver to unregister
2730  *
2731  * This function is used to unregister drivers using the composite
2732  * driver framework.
2733  */
usb_composite_unregister(struct usb_composite_driver * driver)2734 void usb_composite_unregister(struct usb_composite_driver *driver)
2735 {
2736 	usb_gadget_unregister_driver(&driver->gadget_driver);
2737 }
2738 EXPORT_SYMBOL_GPL(usb_composite_unregister);
2739 
2740 /**
2741  * usb_composite_setup_continue() - Continue with the control transfer
2742  * @cdev: the composite device who's control transfer was kept waiting
2743  *
2744  * This function must be called by the USB function driver to continue
2745  * with the control transfer's data/status stage in case it had requested to
2746  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
2747  * can request the composite framework to delay the setup request's data/status
2748  * stages by returning USB_GADGET_DELAYED_STATUS.
2749  */
usb_composite_setup_continue(struct usb_composite_dev * cdev)2750 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
2751 {
2752 	int			value;
2753 	struct usb_request	*req = cdev->req;
2754 	unsigned long		flags;
2755 
2756 	DBG(cdev, "%s\n", __func__);
2757 	spin_lock_irqsave(&cdev->lock, flags);
2758 
2759 	if (cdev->delayed_status == 0) {
2760 		WARN(cdev, "%s: Unexpected call\n", __func__);
2761 
2762 	} else if (--cdev->delayed_status == 0) {
2763 		DBG(cdev, "%s: Completing delayed status\n", __func__);
2764 		req->length = 0;
2765 		req->context = cdev;
2766 		value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
2767 		if (value < 0) {
2768 			DBG(cdev, "ep_queue --> %d\n", value);
2769 			req->status = 0;
2770 			composite_setup_complete(cdev->gadget->ep0, req);
2771 		}
2772 	}
2773 
2774 	spin_unlock_irqrestore(&cdev->lock, flags);
2775 }
2776 EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
2777 
composite_default_mfr(struct usb_gadget * gadget)2778 static char *composite_default_mfr(struct usb_gadget *gadget)
2779 {
2780 	return kasprintf(GFP_KERNEL, "%s %s with %s", init_utsname()->sysname,
2781 			 init_utsname()->release, gadget->name);
2782 }
2783 
usb_composite_overwrite_options(struct usb_composite_dev * cdev,struct usb_composite_overwrite * covr)2784 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
2785 		struct usb_composite_overwrite *covr)
2786 {
2787 	struct usb_device_descriptor	*desc = &cdev->desc;
2788 	struct usb_gadget_strings	*gstr = cdev->driver->strings[0];
2789 	struct usb_string		*dev_str = gstr->strings;
2790 
2791 	if (covr->idVendor)
2792 		desc->idVendor = cpu_to_le16(covr->idVendor);
2793 
2794 	if (covr->idProduct)
2795 		desc->idProduct = cpu_to_le16(covr->idProduct);
2796 
2797 	if (covr->bcdDevice)
2798 		desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
2799 
2800 	if (covr->serial_number) {
2801 		desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
2802 		dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
2803 	}
2804 	if (covr->manufacturer) {
2805 		desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2806 		dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
2807 
2808 	} else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
2809 		desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2810 		cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
2811 		dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
2812 	}
2813 
2814 	if (covr->product) {
2815 		desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
2816 		dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
2817 	}
2818 }
2819 EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
2820 
2821 MODULE_DESCRIPTION("infrastructure for Composite USB Gadgets");
2822 MODULE_LICENSE("GPL");
2823 MODULE_AUTHOR("David Brownell");
2824