xref: /openbmc/u-boot/drivers/usb/gadget/f_dfu.c (revision 1a05b5f9)
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 
316 		dfu_trigger_reset();
317 		break;
318 	default:
319 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
320 		value = RET_STALL;
321 		break;
322 	}
323 
324 	return value;
325 }
326 
327 static int state_dfu_dnload_sync(struct f_dfu *f_dfu,
328 				 const struct usb_ctrlrequest *ctrl,
329 				 struct usb_gadget *gadget,
330 				 struct usb_request *req)
331 {
332 	int value = 0;
333 
334 	switch (ctrl->bRequest) {
335 	case USB_REQ_DFU_GETSTATUS:
336 		handle_getstatus(req);
337 		value = RET_STAT_LEN;
338 		break;
339 	case USB_REQ_DFU_GETSTATE:
340 		handle_getstate(req);
341 		break;
342 	default:
343 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
344 		value = RET_STALL;
345 		break;
346 	}
347 
348 	return value;
349 }
350 
351 static int state_dfu_dnbusy(struct f_dfu *f_dfu,
352 			    const struct usb_ctrlrequest *ctrl,
353 			    struct usb_gadget *gadget,
354 			    struct usb_request *req)
355 {
356 	int value = 0;
357 
358 	switch (ctrl->bRequest) {
359 	case USB_REQ_DFU_GETSTATUS:
360 		handle_getstatus(req);
361 		value = RET_STAT_LEN;
362 		break;
363 	default:
364 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
365 		value = RET_STALL;
366 		break;
367 	}
368 
369 	return value;
370 }
371 
372 static int state_dfu_dnload_idle(struct f_dfu *f_dfu,
373 				 const struct usb_ctrlrequest *ctrl,
374 				 struct usb_gadget *gadget,
375 				 struct usb_request *req)
376 {
377 	u16 w_value = le16_to_cpu(ctrl->wValue);
378 	u16 len = le16_to_cpu(ctrl->wLength);
379 	int value = 0;
380 
381 	switch (ctrl->bRequest) {
382 	case USB_REQ_DFU_DNLOAD:
383 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
384 		f_dfu->blk_seq_num = w_value;
385 		value = handle_dnload(gadget, len);
386 		break;
387 	case USB_REQ_DFU_ABORT:
388 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
389 		value = RET_ZLP;
390 		break;
391 	case USB_REQ_DFU_GETSTATUS:
392 		handle_getstatus(req);
393 		value = RET_STAT_LEN;
394 		break;
395 	case USB_REQ_DFU_GETSTATE:
396 		handle_getstate(req);
397 		break;
398 	default:
399 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
400 		value = RET_STALL;
401 		break;
402 	}
403 
404 	return value;
405 }
406 
407 static int state_dfu_manifest_sync(struct f_dfu *f_dfu,
408 				   const struct usb_ctrlrequest *ctrl,
409 				   struct usb_gadget *gadget,
410 				   struct usb_request *req)
411 {
412 	int value = 0;
413 
414 	switch (ctrl->bRequest) {
415 	case USB_REQ_DFU_GETSTATUS:
416 		/* We're MainfestationTolerant */
417 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
418 		handle_getstatus(req);
419 		f_dfu->blk_seq_num = 0;
420 		value = RET_STAT_LEN;
421 		break;
422 	case USB_REQ_DFU_GETSTATE:
423 		handle_getstate(req);
424 		break;
425 	default:
426 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
427 		value = RET_STALL;
428 		break;
429 	}
430 
431 	return value;
432 }
433 
434 static int state_dfu_upload_idle(struct f_dfu *f_dfu,
435 				 const struct usb_ctrlrequest *ctrl,
436 				 struct usb_gadget *gadget,
437 				 struct usb_request *req)
438 {
439 	u16 w_value = le16_to_cpu(ctrl->wValue);
440 	u16 len = le16_to_cpu(ctrl->wLength);
441 	int value = 0;
442 
443 	switch (ctrl->bRequest) {
444 	case USB_REQ_DFU_UPLOAD:
445 		/* state transition if less data then requested */
446 		f_dfu->blk_seq_num = w_value;
447 		value = handle_upload(req, len);
448 		if (value >= 0 && value < len)
449 			f_dfu->dfu_state = DFU_STATE_dfuIDLE;
450 		break;
451 	case USB_REQ_DFU_ABORT:
452 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
453 		/* no zlp? */
454 		value = RET_ZLP;
455 		break;
456 	case USB_REQ_DFU_GETSTATUS:
457 		handle_getstatus(req);
458 		value = RET_STAT_LEN;
459 		break;
460 	case USB_REQ_DFU_GETSTATE:
461 		handle_getstate(req);
462 		break;
463 	default:
464 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
465 		value = RET_STALL;
466 		break;
467 	}
468 
469 	return value;
470 }
471 
472 static int state_dfu_error(struct f_dfu *f_dfu,
473 				 const struct usb_ctrlrequest *ctrl,
474 				 struct usb_gadget *gadget,
475 				 struct usb_request *req)
476 {
477 	int value = 0;
478 
479 	switch (ctrl->bRequest) {
480 	case USB_REQ_DFU_GETSTATUS:
481 		handle_getstatus(req);
482 		value = RET_STAT_LEN;
483 		break;
484 	case USB_REQ_DFU_GETSTATE:
485 		handle_getstate(req);
486 		break;
487 	case USB_REQ_DFU_CLRSTATUS:
488 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
489 		f_dfu->dfu_status = DFU_STATUS_OK;
490 		/* no zlp? */
491 		value = RET_ZLP;
492 		break;
493 	default:
494 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
495 		value = RET_STALL;
496 		break;
497 	}
498 
499 	return value;
500 }
501 
502 static dfu_state_fn dfu_state[] = {
503 	state_app_idle,          /* DFU_STATE_appIDLE */
504 	state_app_detach,        /* DFU_STATE_appDETACH */
505 	state_dfu_idle,          /* DFU_STATE_dfuIDLE */
506 	state_dfu_dnload_sync,   /* DFU_STATE_dfuDNLOAD_SYNC */
507 	state_dfu_dnbusy,        /* DFU_STATE_dfuDNBUSY */
508 	state_dfu_dnload_idle,   /* DFU_STATE_dfuDNLOAD_IDLE */
509 	state_dfu_manifest_sync, /* DFU_STATE_dfuMANIFEST_SYNC */
510 	NULL,                    /* DFU_STATE_dfuMANIFEST */
511 	NULL,                    /* DFU_STATE_dfuMANIFEST_WAIT_RST */
512 	state_dfu_upload_idle,   /* DFU_STATE_dfuUPLOAD_IDLE */
513 	state_dfu_error          /* DFU_STATE_dfuERROR */
514 };
515 
516 static int
517 dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
518 {
519 	struct usb_gadget *gadget = f->config->cdev->gadget;
520 	struct usb_request *req = f->config->cdev->req;
521 	struct f_dfu *f_dfu = f->config->cdev->req->context;
522 	u16 len = le16_to_cpu(ctrl->wLength);
523 	u16 w_value = le16_to_cpu(ctrl->wValue);
524 	int value = 0;
525 	u8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
526 
527 	debug("w_value: 0x%x len: 0x%x\n", w_value, len);
528 	debug("req_type: 0x%x ctrl->bRequest: 0x%x f_dfu->dfu_state: 0x%x\n",
529 	       req_type, ctrl->bRequest, f_dfu->dfu_state);
530 
531 	if (req_type == USB_TYPE_STANDARD) {
532 		if (ctrl->bRequest == USB_REQ_GET_DESCRIPTOR &&
533 		    (w_value >> 8) == DFU_DT_FUNC) {
534 			value = min(len, (u16) sizeof(dfu_func));
535 			memcpy(req->buf, &dfu_func, value);
536 		}
537 	} else /* DFU specific request */
538 		value = dfu_state[f_dfu->dfu_state] (f_dfu, ctrl, gadget, req);
539 
540 	if (value >= 0) {
541 		req->length = value;
542 		req->zero = value < len;
543 		value = usb_ep_queue(gadget->ep0, req, 0);
544 		if (value < 0) {
545 			debug("ep_queue --> %d\n", value);
546 			req->status = 0;
547 		}
548 	}
549 
550 	return value;
551 }
552 
553 /*-------------------------------------------------------------------------*/
554 
555 static int
556 dfu_prepare_strings(struct f_dfu *f_dfu, int n)
557 {
558 	struct dfu_entity *de = NULL;
559 	int i = 0;
560 
561 	f_dfu->strings = calloc(sizeof(struct usb_string), n + 1);
562 	if (!f_dfu->strings)
563 		goto enomem;
564 
565 	for (i = 0; i < n; ++i) {
566 		de = dfu_get_entity(i);
567 		f_dfu->strings[i].s = de->name;
568 	}
569 
570 	f_dfu->strings[i].id = 0;
571 	f_dfu->strings[i].s = NULL;
572 
573 	return 0;
574 
575 enomem:
576 	while (i)
577 		f_dfu->strings[--i].s = NULL;
578 
579 	free(f_dfu->strings);
580 
581 	return -ENOMEM;
582 }
583 
584 static int dfu_prepare_function(struct f_dfu *f_dfu, int n)
585 {
586 	struct usb_interface_descriptor *d;
587 	int i = 0;
588 
589 	f_dfu->function = calloc(sizeof(struct usb_descriptor_header *), n + 1);
590 	if (!f_dfu->function)
591 		goto enomem;
592 
593 	for (i = 0; i < n; ++i) {
594 		d = calloc(sizeof(*d), 1);
595 		if (!d)
596 			goto enomem;
597 
598 		d->bLength =		sizeof(*d);
599 		d->bDescriptorType =	USB_DT_INTERFACE;
600 		d->bAlternateSetting =	i;
601 		d->bNumEndpoints =	0;
602 		d->bInterfaceClass =	USB_CLASS_APP_SPEC;
603 		d->bInterfaceSubClass =	1;
604 		d->bInterfaceProtocol =	2;
605 
606 		f_dfu->function[i] = (struct usb_descriptor_header *)d;
607 	}
608 	f_dfu->function[i] = NULL;
609 
610 	return 0;
611 
612 enomem:
613 	while (i) {
614 		free(f_dfu->function[--i]);
615 		f_dfu->function[i] = NULL;
616 	}
617 	free(f_dfu->function);
618 
619 	return -ENOMEM;
620 }
621 
622 static int dfu_bind(struct usb_configuration *c, struct usb_function *f)
623 {
624 	struct usb_composite_dev *cdev = c->cdev;
625 	struct f_dfu *f_dfu = func_to_dfu(f);
626 	int alt_num = dfu_get_alt_number();
627 	int rv, id, i;
628 
629 	id = usb_interface_id(c, f);
630 	if (id < 0)
631 		return id;
632 	dfu_intf_runtime.bInterfaceNumber = id;
633 
634 	f_dfu->dfu_state = DFU_STATE_appIDLE;
635 	f_dfu->dfu_status = DFU_STATUS_OK;
636 
637 	rv = dfu_prepare_function(f_dfu, alt_num);
638 	if (rv)
639 		goto error;
640 
641 	rv = dfu_prepare_strings(f_dfu, alt_num);
642 	if (rv)
643 		goto error;
644 	for (i = 0; i < alt_num; i++) {
645 		id = usb_string_id(cdev);
646 		if (id < 0)
647 			return id;
648 		f_dfu->strings[i].id = id;
649 		((struct usb_interface_descriptor *)f_dfu->function[i])
650 			->iInterface = id;
651 	}
652 
653 	to_dfu_mode(f_dfu);
654 
655 	stringtab_dfu.strings = f_dfu->strings;
656 
657 	cdev->req->context = f_dfu;
658 
659 error:
660 	return rv;
661 }
662 
663 static void dfu_unbind(struct usb_configuration *c, struct usb_function *f)
664 {
665 	struct f_dfu *f_dfu = func_to_dfu(f);
666 	int alt_num = dfu_get_alt_number();
667 	int i;
668 
669 	if (f_dfu->strings) {
670 		i = alt_num;
671 		while (i)
672 			f_dfu->strings[--i].s = NULL;
673 
674 		free(f_dfu->strings);
675 	}
676 
677 	if (f_dfu->function) {
678 		i = alt_num;
679 		while (i) {
680 			free(f_dfu->function[--i]);
681 			f_dfu->function[i] = NULL;
682 		}
683 		free(f_dfu->function);
684 	}
685 
686 	free(f_dfu);
687 }
688 
689 static int dfu_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
690 {
691 	struct f_dfu *f_dfu = func_to_dfu(f);
692 
693 	debug("%s: intf:%d alt:%d\n", __func__, intf, alt);
694 
695 	f_dfu->altsetting = alt;
696 
697 	return 0;
698 }
699 
700 /* TODO: is this really what we need here? */
701 static void dfu_disable(struct usb_function *f)
702 {
703 	struct f_dfu *f_dfu = func_to_dfu(f);
704 	if (f_dfu->config == 0)
705 		return;
706 
707 	debug("%s: reset config\n", __func__);
708 
709 	f_dfu->config = 0;
710 }
711 
712 static int dfu_bind_config(struct usb_configuration *c)
713 {
714 	struct f_dfu *f_dfu;
715 	int status;
716 
717 	f_dfu = calloc(sizeof(*f_dfu), 1);
718 	if (!f_dfu)
719 		return -ENOMEM;
720 	f_dfu->usb_function.name = "dfu";
721 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
722 	f_dfu->usb_function.bind = dfu_bind;
723 	f_dfu->usb_function.unbind = dfu_unbind;
724 	f_dfu->usb_function.set_alt = dfu_set_alt;
725 	f_dfu->usb_function.disable = dfu_disable;
726 	f_dfu->usb_function.strings = dfu_generic_strings,
727 	f_dfu->usb_function.setup = dfu_handle,
728 
729 	status = usb_add_function(c, &f_dfu->usb_function);
730 	if (status)
731 		free(f_dfu);
732 
733 	return status;
734 }
735 
736 int dfu_add(struct usb_configuration *c)
737 {
738 	int id;
739 
740 	id = usb_string_id(c->cdev);
741 	if (id < 0)
742 		return id;
743 	strings_dfu_generic[0].id = id;
744 	dfu_intf_runtime.iInterface = id;
745 
746 	debug("%s: cdev: 0x%p gadget:0x%p gadget->ep0: 0x%p\n", __func__,
747 	       c->cdev, c->cdev->gadget, c->cdev->gadget->ep0);
748 
749 	return dfu_bind_config(c);
750 }
751