xref: /openbmc/u-boot/drivers/usb/gadget/f_dfu.c (revision a2ac68fb2b35e57cd483e7d6fb30b9d9331acc01) 
1 /*
2  * f_dfu.c -- Device Firmware Update USB function
3  *
4  * Copyright (C) 2012 Samsung Electronics
5  * authors: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
6  *          Lukasz Majewski <l.majewski@samsung.com>
7  *
8  * Based on OpenMoko u-boot: drivers/usb/usbdfu.c
9  * (C) 2007 by OpenMoko, Inc.
10  * Author: Harald Welte <laforge@openmoko.org>
11  *
12  * based on existing SAM7DFU code from OpenPCD:
13  * (C) Copyright 2006 by Harald Welte <hwelte at hmw-consulting.de>
14  *
15  * SPDX-License-Identifier:	GPL-2.0+
16  */
17 
18 #include <errno.h>
19 #include <common.h>
20 #include <malloc.h>
21 
22 #include <linux/usb/ch9.h>
23 #include <linux/usb/gadget.h>
24 #include <linux/usb/composite.h>
25 
26 #include <dfu.h>
27 #include "f_dfu.h"
28 
29 struct f_dfu {
30 	struct usb_function		usb_function;
31 
32 	struct usb_descriptor_header	**function;
33 	struct usb_string		*strings;
34 
35 	/* when configured, we have one config */
36 	u8				config;
37 	u8				altsetting;
38 	enum dfu_state			dfu_state;
39 	unsigned int			dfu_status;
40 
41 	/* Send/received block number is handy for data integrity check */
42 	int                             blk_seq_num;
43 };
44 
45 typedef int (*dfu_state_fn) (struct f_dfu *,
46 			     const struct usb_ctrlrequest *,
47 			     struct usb_gadget *,
48 			     struct usb_request *);
49 
50 static inline struct f_dfu *func_to_dfu(struct usb_function *f)
51 {
52 	return container_of(f, struct f_dfu, usb_function);
53 }
54 
55 static const struct dfu_function_descriptor dfu_func = {
56 	.bLength =		sizeof dfu_func,
57 	.bDescriptorType =	DFU_DT_FUNC,
58 	.bmAttributes =		DFU_BIT_WILL_DETACH |
59 				DFU_BIT_MANIFESTATION_TOLERANT |
60 				DFU_BIT_CAN_UPLOAD |
61 				DFU_BIT_CAN_DNLOAD,
62 	.wDetachTimeOut =	0,
63 	.wTransferSize =	DFU_USB_BUFSIZ,
64 	.bcdDFUVersion =	__constant_cpu_to_le16(0x0110),
65 };
66 
67 static struct usb_interface_descriptor dfu_intf_runtime = {
68 	.bLength =		sizeof dfu_intf_runtime,
69 	.bDescriptorType =	USB_DT_INTERFACE,
70 	.bNumEndpoints =	0,
71 	.bInterfaceClass =	USB_CLASS_APP_SPEC,
72 	.bInterfaceSubClass =	1,
73 	.bInterfaceProtocol =	1,
74 	/* .iInterface = DYNAMIC */
75 };
76 
77 static struct usb_descriptor_header *dfu_runtime_descs[] = {
78 	(struct usb_descriptor_header *) &dfu_intf_runtime,
79 	NULL,
80 };
81 
82 static const struct usb_qualifier_descriptor dev_qualifier = {
83 	.bLength =		sizeof dev_qualifier,
84 	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
85 	.bcdUSB =		__constant_cpu_to_le16(0x0200),
86 	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
87 	.bNumConfigurations =	1,
88 };
89 
90 static const char dfu_name[] = "Device Firmware Upgrade";
91 
92 /*
93  * static strings, in UTF-8
94  *
95  * dfu_generic configuration
96  */
97 static struct usb_string strings_dfu_generic[] = {
98 	[0].s = dfu_name,
99 	{  }			/* end of list */
100 };
101 
102 static struct usb_gadget_strings stringtab_dfu_generic = {
103 	.language	= 0x0409,	/* en-us */
104 	.strings	= strings_dfu_generic,
105 };
106 
107 static struct usb_gadget_strings *dfu_generic_strings[] = {
108 	&stringtab_dfu_generic,
109 	NULL,
110 };
111 
112 /*
113  * usb_function specific
114  */
115 static struct usb_gadget_strings stringtab_dfu = {
116 	.language	= 0x0409,	/* en-us */
117 	/*
118 	 * .strings
119 	 *
120 	 * assigned during initialization,
121 	 * depends on number of flash entities
122 	 *
123 	 */
124 };
125 
126 static struct usb_gadget_strings *dfu_strings[] = {
127 	&stringtab_dfu,
128 	NULL,
129 };
130 
131 /*-------------------------------------------------------------------------*/
132 
133 static void dnload_request_complete(struct usb_ep *ep, struct usb_request *req)
134 {
135 	struct f_dfu *f_dfu = req->context;
136 
137 	dfu_write(dfu_get_entity(f_dfu->altsetting), req->buf,
138 		  req->length, f_dfu->blk_seq_num);
139 
140 	if (req->length == 0)
141 		puts("DOWNLOAD ... OK\nCtrl+C to exit ...\n");
142 }
143 
144 static void handle_getstatus(struct usb_request *req)
145 {
146 	struct dfu_status *dstat = (struct dfu_status *)req->buf;
147 	struct f_dfu *f_dfu = req->context;
148 
149 	switch (f_dfu->dfu_state) {
150 	case DFU_STATE_dfuDNLOAD_SYNC:
151 	case DFU_STATE_dfuDNBUSY:
152 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_IDLE;
153 		break;
154 	case DFU_STATE_dfuMANIFEST_SYNC:
155 		break;
156 	default:
157 		break;
158 	}
159 
160 	/* send status response */
161 	dstat->bStatus = f_dfu->dfu_status;
162 	dstat->bwPollTimeout[0] = 0;
163 	dstat->bwPollTimeout[1] = 0;
164 	dstat->bwPollTimeout[2] = 0;
165 	dstat->bState = f_dfu->dfu_state;
166 	dstat->iString = 0;
167 }
168 
169 static void handle_getstate(struct usb_request *req)
170 {
171 	struct f_dfu *f_dfu = req->context;
172 
173 	((u8 *)req->buf)[0] = f_dfu->dfu_state;
174 	req->actual = sizeof(u8);
175 }
176 
177 static inline void to_dfu_mode(struct f_dfu *f_dfu)
178 {
179 	f_dfu->usb_function.strings = dfu_strings;
180 	f_dfu->usb_function.hs_descriptors = f_dfu->function;
181 	f_dfu->dfu_state = DFU_STATE_dfuIDLE;
182 }
183 
184 static inline void to_runtime_mode(struct f_dfu *f_dfu)
185 {
186 	f_dfu->usb_function.strings = NULL;
187 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
188 }
189 
190 static int handle_upload(struct usb_request *req, u16 len)
191 {
192 	struct f_dfu *f_dfu = req->context;
193 
194 	return dfu_read(dfu_get_entity(f_dfu->altsetting), req->buf,
195 			req->length, f_dfu->blk_seq_num);
196 }
197 
198 static int handle_dnload(struct usb_gadget *gadget, u16 len)
199 {
200 	struct usb_composite_dev *cdev = get_gadget_data(gadget);
201 	struct usb_request *req = cdev->req;
202 	struct f_dfu *f_dfu = req->context;
203 
204 	if (len == 0)
205 		f_dfu->dfu_state = DFU_STATE_dfuMANIFEST_SYNC;
206 
207 	req->complete = dnload_request_complete;
208 
209 	return len;
210 }
211 
212 /*-------------------------------------------------------------------------*/
213 /* DFU state machine  */
214 static int state_app_idle(struct f_dfu *f_dfu,
215 			  const struct usb_ctrlrequest *ctrl,
216 			  struct usb_gadget *gadget,
217 			  struct usb_request *req)
218 {
219 	int value = 0;
220 
221 	switch (ctrl->bRequest) {
222 	case USB_REQ_DFU_GETSTATUS:
223 		handle_getstatus(req);
224 		value = RET_STAT_LEN;
225 		break;
226 	case USB_REQ_DFU_GETSTATE:
227 		handle_getstate(req);
228 		break;
229 	case USB_REQ_DFU_DETACH:
230 		f_dfu->dfu_state = DFU_STATE_appDETACH;
231 		to_dfu_mode(f_dfu);
232 		value = RET_ZLP;
233 		break;
234 	default:
235 		value = RET_STALL;
236 		break;
237 	}
238 
239 	return value;
240 }
241 
242 static int state_app_detach(struct f_dfu *f_dfu,
243 			    const struct usb_ctrlrequest *ctrl,
244 			    struct usb_gadget *gadget,
245 			    struct usb_request *req)
246 {
247 	int value = 0;
248 
249 	switch (ctrl->bRequest) {
250 	case USB_REQ_DFU_GETSTATUS:
251 		handle_getstatus(req);
252 		value = RET_STAT_LEN;
253 		break;
254 	case USB_REQ_DFU_GETSTATE:
255 		handle_getstate(req);
256 		break;
257 	default:
258 		f_dfu->dfu_state = DFU_STATE_appIDLE;
259 		value = RET_STALL;
260 		break;
261 	}
262 
263 	return value;
264 }
265 
266 static int state_dfu_idle(struct f_dfu *f_dfu,
267 			  const struct usb_ctrlrequest *ctrl,
268 			  struct usb_gadget *gadget,
269 			  struct usb_request *req)
270 {
271 	u16 w_value = le16_to_cpu(ctrl->wValue);
272 	u16 len = le16_to_cpu(ctrl->wLength);
273 	int value = 0;
274 
275 	switch (ctrl->bRequest) {
276 	case USB_REQ_DFU_DNLOAD:
277 		if (len == 0) {
278 			f_dfu->dfu_state = DFU_STATE_dfuERROR;
279 			value = RET_STALL;
280 			break;
281 		}
282 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
283 		f_dfu->blk_seq_num = w_value;
284 		value = handle_dnload(gadget, len);
285 		break;
286 	case USB_REQ_DFU_UPLOAD:
287 		f_dfu->dfu_state = DFU_STATE_dfuUPLOAD_IDLE;
288 		f_dfu->blk_seq_num = 0;
289 		value = handle_upload(req, len);
290 		break;
291 	case USB_REQ_DFU_ABORT:
292 		/* no zlp? */
293 		value = RET_ZLP;
294 		break;
295 	case USB_REQ_DFU_GETSTATUS:
296 		handle_getstatus(req);
297 		value = RET_STAT_LEN;
298 		break;
299 	case USB_REQ_DFU_GETSTATE:
300 		handle_getstate(req);
301 		break;
302 	case USB_REQ_DFU_DETACH:
303 		/*
304 		 * Proprietary extension: 'detach' from idle mode and
305 		 * get back to runtime mode in case of USB Reset.  As
306 		 * much as I dislike this, we just can't use every USB
307 		 * bus reset to switch back to runtime mode, since at
308 		 * least the Linux USB stack likes to send a number of
309 		 * resets in a row :(
310 		 */
311 		f_dfu->dfu_state =
312 			DFU_STATE_dfuMANIFEST_WAIT_RST;
313 		to_runtime_mode(f_dfu);
314 		f_dfu->dfu_state = DFU_STATE_appIDLE;
315 		break;
316 	default:
317 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
318 		value = RET_STALL;
319 		break;
320 	}
321 
322 	return value;
323 }
324 
325 static int state_dfu_dnload_sync(struct f_dfu *f_dfu,
326 				 const struct usb_ctrlrequest *ctrl,
327 				 struct usb_gadget *gadget,
328 				 struct usb_request *req)
329 {
330 	int value = 0;
331 
332 	switch (ctrl->bRequest) {
333 	case USB_REQ_DFU_GETSTATUS:
334 		handle_getstatus(req);
335 		value = RET_STAT_LEN;
336 		break;
337 	case USB_REQ_DFU_GETSTATE:
338 		handle_getstate(req);
339 		break;
340 	default:
341 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
342 		value = RET_STALL;
343 		break;
344 	}
345 
346 	return value;
347 }
348 
349 static int state_dfu_dnbusy(struct f_dfu *f_dfu,
350 			    const struct usb_ctrlrequest *ctrl,
351 			    struct usb_gadget *gadget,
352 			    struct usb_request *req)
353 {
354 	int value = 0;
355 
356 	switch (ctrl->bRequest) {
357 	case USB_REQ_DFU_GETSTATUS:
358 		handle_getstatus(req);
359 		value = RET_STAT_LEN;
360 		break;
361 	default:
362 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
363 		value = RET_STALL;
364 		break;
365 	}
366 
367 	return value;
368 }
369 
370 static int state_dfu_dnload_idle(struct f_dfu *f_dfu,
371 				 const struct usb_ctrlrequest *ctrl,
372 				 struct usb_gadget *gadget,
373 				 struct usb_request *req)
374 {
375 	u16 w_value = le16_to_cpu(ctrl->wValue);
376 	u16 len = le16_to_cpu(ctrl->wLength);
377 	int value = 0;
378 
379 	switch (ctrl->bRequest) {
380 	case USB_REQ_DFU_DNLOAD:
381 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
382 		f_dfu->blk_seq_num = w_value;
383 		value = handle_dnload(gadget, len);
384 		break;
385 	case USB_REQ_DFU_ABORT:
386 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
387 		value = RET_ZLP;
388 		break;
389 	case USB_REQ_DFU_GETSTATUS:
390 		handle_getstatus(req);
391 		value = RET_STAT_LEN;
392 		break;
393 	case USB_REQ_DFU_GETSTATE:
394 		handle_getstate(req);
395 		break;
396 	default:
397 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
398 		value = RET_STALL;
399 		break;
400 	}
401 
402 	return value;
403 }
404 
405 static int state_dfu_manifest_sync(struct f_dfu *f_dfu,
406 				   const struct usb_ctrlrequest *ctrl,
407 				   struct usb_gadget *gadget,
408 				   struct usb_request *req)
409 {
410 	int value = 0;
411 
412 	switch (ctrl->bRequest) {
413 	case USB_REQ_DFU_GETSTATUS:
414 		/* We're MainfestationTolerant */
415 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
416 		handle_getstatus(req);
417 		f_dfu->blk_seq_num = 0;
418 		value = RET_STAT_LEN;
419 		break;
420 	case USB_REQ_DFU_GETSTATE:
421 		handle_getstate(req);
422 		break;
423 	default:
424 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
425 		value = RET_STALL;
426 		break;
427 	}
428 
429 	return value;
430 }
431 
432 static int state_dfu_upload_idle(struct f_dfu *f_dfu,
433 				 const struct usb_ctrlrequest *ctrl,
434 				 struct usb_gadget *gadget,
435 				 struct usb_request *req)
436 {
437 	u16 w_value = le16_to_cpu(ctrl->wValue);
438 	u16 len = le16_to_cpu(ctrl->wLength);
439 	int value = 0;
440 
441 	switch (ctrl->bRequest) {
442 	case USB_REQ_DFU_UPLOAD:
443 		/* state transition if less data then requested */
444 		f_dfu->blk_seq_num = w_value;
445 		value = handle_upload(req, len);
446 		if (value >= 0 && value < len)
447 			f_dfu->dfu_state = DFU_STATE_dfuIDLE;
448 		break;
449 	case USB_REQ_DFU_ABORT:
450 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
451 		/* no zlp? */
452 		value = RET_ZLP;
453 		break;
454 	case USB_REQ_DFU_GETSTATUS:
455 		handle_getstatus(req);
456 		value = RET_STAT_LEN;
457 		break;
458 	case USB_REQ_DFU_GETSTATE:
459 		handle_getstate(req);
460 		break;
461 	default:
462 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
463 		value = RET_STALL;
464 		break;
465 	}
466 
467 	return value;
468 }
469 
470 static int state_dfu_error(struct f_dfu *f_dfu,
471 				 const struct usb_ctrlrequest *ctrl,
472 				 struct usb_gadget *gadget,
473 				 struct usb_request *req)
474 {
475 	int value = 0;
476 
477 	switch (ctrl->bRequest) {
478 	case USB_REQ_DFU_GETSTATUS:
479 		handle_getstatus(req);
480 		value = RET_STAT_LEN;
481 		break;
482 	case USB_REQ_DFU_GETSTATE:
483 		handle_getstate(req);
484 		break;
485 	case USB_REQ_DFU_CLRSTATUS:
486 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
487 		f_dfu->dfu_status = DFU_STATUS_OK;
488 		/* no zlp? */
489 		value = RET_ZLP;
490 		break;
491 	default:
492 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
493 		value = RET_STALL;
494 		break;
495 	}
496 
497 	return value;
498 }
499 
500 static dfu_state_fn dfu_state[] = {
501 	state_app_idle,          /* DFU_STATE_appIDLE */
502 	state_app_detach,        /* DFU_STATE_appDETACH */
503 	state_dfu_idle,          /* DFU_STATE_dfuIDLE */
504 	state_dfu_dnload_sync,   /* DFU_STATE_dfuDNLOAD_SYNC */
505 	state_dfu_dnbusy,        /* DFU_STATE_dfuDNBUSY */
506 	state_dfu_dnload_idle,   /* DFU_STATE_dfuDNLOAD_IDLE */
507 	state_dfu_manifest_sync, /* DFU_STATE_dfuMANIFEST_SYNC */
508 	NULL,                    /* DFU_STATE_dfuMANIFEST */
509 	NULL,                    /* DFU_STATE_dfuMANIFEST_WAIT_RST */
510 	state_dfu_upload_idle,   /* DFU_STATE_dfuUPLOAD_IDLE */
511 	state_dfu_error          /* DFU_STATE_dfuERROR */
512 };
513 
514 static int
515 dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
516 {
517 	struct usb_gadget *gadget = f->config->cdev->gadget;
518 	struct usb_request *req = f->config->cdev->req;
519 	struct f_dfu *f_dfu = f->config->cdev->req->context;
520 	u16 len = le16_to_cpu(ctrl->wLength);
521 	u16 w_value = le16_to_cpu(ctrl->wValue);
522 	int value = 0;
523 	u8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
524 
525 	debug("w_value: 0x%x len: 0x%x\n", w_value, len);
526 	debug("req_type: 0x%x ctrl->bRequest: 0x%x f_dfu->dfu_state: 0x%x\n",
527 	       req_type, ctrl->bRequest, f_dfu->dfu_state);
528 
529 	if (req_type == USB_TYPE_STANDARD) {
530 		if (ctrl->bRequest == USB_REQ_GET_DESCRIPTOR &&
531 		    (w_value >> 8) == DFU_DT_FUNC) {
532 			value = min(len, (u16) sizeof(dfu_func));
533 			memcpy(req->buf, &dfu_func, value);
534 		}
535 	} else /* DFU specific request */
536 		value = dfu_state[f_dfu->dfu_state] (f_dfu, ctrl, gadget, req);
537 
538 	if (value >= 0) {
539 		req->length = value;
540 		req->zero = value < len;
541 		value = usb_ep_queue(gadget->ep0, req, 0);
542 		if (value < 0) {
543 			debug("ep_queue --> %d\n", value);
544 			req->status = 0;
545 		}
546 	}
547 
548 	return value;
549 }
550 
551 /*-------------------------------------------------------------------------*/
552 
553 static int
554 dfu_prepare_strings(struct f_dfu *f_dfu, int n)
555 {
556 	struct dfu_entity *de = NULL;
557 	int i = 0;
558 
559 	f_dfu->strings = calloc(sizeof(struct usb_string), n + 1);
560 	if (!f_dfu->strings)
561 		goto enomem;
562 
563 	for (i = 0; i < n; ++i) {
564 		de = dfu_get_entity(i);
565 		f_dfu->strings[i].s = de->name;
566 	}
567 
568 	f_dfu->strings[i].id = 0;
569 	f_dfu->strings[i].s = NULL;
570 
571 	return 0;
572 
573 enomem:
574 	while (i)
575 		f_dfu->strings[--i].s = NULL;
576 
577 	free(f_dfu->strings);
578 
579 	return -ENOMEM;
580 }
581 
582 static int dfu_prepare_function(struct f_dfu *f_dfu, int n)
583 {
584 	struct usb_interface_descriptor *d;
585 	int i = 0;
586 
587 	f_dfu->function = calloc(sizeof(struct usb_descriptor_header *), n + 1);
588 	if (!f_dfu->function)
589 		goto enomem;
590 
591 	for (i = 0; i < n; ++i) {
592 		d = calloc(sizeof(*d), 1);
593 		if (!d)
594 			goto enomem;
595 
596 		d->bLength =		sizeof(*d);
597 		d->bDescriptorType =	USB_DT_INTERFACE;
598 		d->bAlternateSetting =	i;
599 		d->bNumEndpoints =	0;
600 		d->bInterfaceClass =	USB_CLASS_APP_SPEC;
601 		d->bInterfaceSubClass =	1;
602 		d->bInterfaceProtocol =	2;
603 
604 		f_dfu->function[i] = (struct usb_descriptor_header *)d;
605 	}
606 	f_dfu->function[i] = NULL;
607 
608 	return 0;
609 
610 enomem:
611 	while (i) {
612 		free(f_dfu->function[--i]);
613 		f_dfu->function[i] = NULL;
614 	}
615 	free(f_dfu->function);
616 
617 	return -ENOMEM;
618 }
619 
620 static int dfu_bind(struct usb_configuration *c, struct usb_function *f)
621 {
622 	struct usb_composite_dev *cdev = c->cdev;
623 	struct f_dfu *f_dfu = func_to_dfu(f);
624 	int alt_num = dfu_get_alt_number();
625 	int rv, id, i;
626 
627 	id = usb_interface_id(c, f);
628 	if (id < 0)
629 		return id;
630 	dfu_intf_runtime.bInterfaceNumber = id;
631 
632 	f_dfu->dfu_state = DFU_STATE_appIDLE;
633 	f_dfu->dfu_status = DFU_STATUS_OK;
634 
635 	rv = dfu_prepare_function(f_dfu, alt_num);
636 	if (rv)
637 		goto error;
638 
639 	rv = dfu_prepare_strings(f_dfu, alt_num);
640 	if (rv)
641 		goto error;
642 	for (i = 0; i < alt_num; i++) {
643 		id = usb_string_id(cdev);
644 		if (id < 0)
645 			return id;
646 		f_dfu->strings[i].id = id;
647 		((struct usb_interface_descriptor *)f_dfu->function[i])
648 			->iInterface = id;
649 	}
650 
651 	to_dfu_mode(f_dfu);
652 
653 	stringtab_dfu.strings = f_dfu->strings;
654 
655 	cdev->req->context = f_dfu;
656 
657 error:
658 	return rv;
659 }
660 
661 static void dfu_unbind(struct usb_configuration *c, struct usb_function *f)
662 {
663 	struct f_dfu *f_dfu = func_to_dfu(f);
664 	int alt_num = dfu_get_alt_number();
665 	int i;
666 
667 	if (f_dfu->strings) {
668 		i = alt_num;
669 		while (i)
670 			f_dfu->strings[--i].s = NULL;
671 
672 		free(f_dfu->strings);
673 	}
674 
675 	if (f_dfu->function) {
676 		i = alt_num;
677 		while (i) {
678 			free(f_dfu->function[--i]);
679 			f_dfu->function[i] = NULL;
680 		}
681 		free(f_dfu->function);
682 	}
683 
684 	free(f_dfu);
685 }
686 
687 static int dfu_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
688 {
689 	struct f_dfu *f_dfu = func_to_dfu(f);
690 
691 	debug("%s: intf:%d alt:%d\n", __func__, intf, alt);
692 
693 	f_dfu->altsetting = alt;
694 
695 	return 0;
696 }
697 
698 /* TODO: is this really what we need here? */
699 static void dfu_disable(struct usb_function *f)
700 {
701 	struct f_dfu *f_dfu = func_to_dfu(f);
702 	if (f_dfu->config == 0)
703 		return;
704 
705 	debug("%s: reset config\n", __func__);
706 
707 	f_dfu->config = 0;
708 }
709 
710 static int dfu_bind_config(struct usb_configuration *c)
711 {
712 	struct f_dfu *f_dfu;
713 	int status;
714 
715 	f_dfu = calloc(sizeof(*f_dfu), 1);
716 	if (!f_dfu)
717 		return -ENOMEM;
718 	f_dfu->usb_function.name = "dfu";
719 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
720 	f_dfu->usb_function.bind = dfu_bind;
721 	f_dfu->usb_function.unbind = dfu_unbind;
722 	f_dfu->usb_function.set_alt = dfu_set_alt;
723 	f_dfu->usb_function.disable = dfu_disable;
724 	f_dfu->usb_function.strings = dfu_generic_strings,
725 	f_dfu->usb_function.setup = dfu_handle,
726 
727 	status = usb_add_function(c, &f_dfu->usb_function);
728 	if (status)
729 		free(f_dfu);
730 
731 	return status;
732 }
733 
734 int dfu_add(struct usb_configuration *c)
735 {
736 	int id;
737 
738 	id = usb_string_id(c->cdev);
739 	if (id < 0)
740 		return id;
741 	strings_dfu_generic[0].id = id;
742 	dfu_intf_runtime.iInterface = id;
743 
744 	debug("%s: cdev: 0x%p gadget:0x%p gadget->ep0: 0x%p\n", __func__,
745 	       c->cdev, c->cdev->gadget, c->cdev->gadget->ep0);
746 
747 	return dfu_bind_config(c);
748 }
749