xref: /openbmc/u-boot/drivers/usb/gadget/f_dfu.c (revision af2a4093)
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  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #include <errno.h>
24 #include <common.h>
25 #include <malloc.h>
26 
27 #include <linux/usb/ch9.h>
28 #include <usbdescriptors.h>
29 #include <linux/usb/gadget.h>
30 #include <linux/usb/composite.h>
31 
32 #include <dfu.h>
33 #include "f_dfu.h"
34 
35 struct f_dfu {
36 	struct usb_function		usb_function;
37 
38 	struct usb_descriptor_header	**function;
39 	struct usb_string		*strings;
40 
41 	/* when configured, we have one config */
42 	u8				config;
43 	u8				altsetting;
44 	enum dfu_state			dfu_state;
45 	unsigned int			dfu_status;
46 
47 	/* Send/received block number is handy for data integrity check */
48 	int                             blk_seq_num;
49 };
50 
51 typedef int (*dfu_state_fn) (struct f_dfu *,
52 			     const struct usb_ctrlrequest *,
53 			     struct usb_gadget *,
54 			     struct usb_request *);
55 
56 static inline struct f_dfu *func_to_dfu(struct usb_function *f)
57 {
58 	return container_of(f, struct f_dfu, usb_function);
59 }
60 
61 static const struct dfu_function_descriptor dfu_func = {
62 	.bLength =		sizeof dfu_func,
63 	.bDescriptorType =	DFU_DT_FUNC,
64 	.bmAttributes =		DFU_BIT_WILL_DETACH |
65 				DFU_BIT_MANIFESTATION_TOLERANT |
66 				DFU_BIT_CAN_UPLOAD |
67 				DFU_BIT_CAN_DNLOAD,
68 	.wDetachTimeOut =	0,
69 	.wTransferSize =	DFU_USB_BUFSIZ,
70 	.bcdDFUVersion =	__constant_cpu_to_le16(0x0110),
71 };
72 
73 static struct usb_interface_descriptor dfu_intf_runtime = {
74 	.bLength =		sizeof dfu_intf_runtime,
75 	.bDescriptorType =	USB_DT_INTERFACE,
76 	.bNumEndpoints =	0,
77 	.bInterfaceClass =	USB_CLASS_APP_SPEC,
78 	.bInterfaceSubClass =	1,
79 	.bInterfaceProtocol =	1,
80 	/* .iInterface = DYNAMIC */
81 };
82 
83 static struct usb_descriptor_header *dfu_runtime_descs[] = {
84 	(struct usb_descriptor_header *) &dfu_intf_runtime,
85 	NULL,
86 };
87 
88 static const struct usb_qualifier_descriptor dev_qualifier = {
89 	.bLength =		sizeof dev_qualifier,
90 	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
91 	.bcdUSB =		__constant_cpu_to_le16(0x0200),
92 	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
93 	.bNumConfigurations =	1,
94 };
95 
96 static const char dfu_name[] = "Device Firmware Upgrade";
97 
98 /*
99  * static strings, in UTF-8
100  *
101  * dfu_generic configuration
102  */
103 static struct usb_string strings_dfu_generic[] = {
104 	[0].s = dfu_name,
105 	{  }			/* end of list */
106 };
107 
108 static struct usb_gadget_strings stringtab_dfu_generic = {
109 	.language	= 0x0409,	/* en-us */
110 	.strings	= strings_dfu_generic,
111 };
112 
113 static struct usb_gadget_strings *dfu_generic_strings[] = {
114 	&stringtab_dfu_generic,
115 	NULL,
116 };
117 
118 /*
119  * usb_function specific
120  */
121 static struct usb_gadget_strings stringtab_dfu = {
122 	.language	= 0x0409,	/* en-us */
123 	/*
124 	 * .strings
125 	 *
126 	 * assigned during initialization,
127 	 * depends on number of flash entities
128 	 *
129 	 */
130 };
131 
132 static struct usb_gadget_strings *dfu_strings[] = {
133 	&stringtab_dfu,
134 	NULL,
135 };
136 
137 /*-------------------------------------------------------------------------*/
138 
139 static void dnload_request_complete(struct usb_ep *ep, struct usb_request *req)
140 {
141 	struct f_dfu *f_dfu = req->context;
142 
143 	dfu_write(dfu_get_entity(f_dfu->altsetting), req->buf,
144 		  req->length, f_dfu->blk_seq_num);
145 
146 	if (req->length == 0)
147 		puts("DOWNLOAD ... OK\nCtrl+C to exit ...\n");
148 }
149 
150 static void handle_getstatus(struct usb_request *req)
151 {
152 	struct dfu_status *dstat = (struct dfu_status *)req->buf;
153 	struct f_dfu *f_dfu = req->context;
154 
155 	switch (f_dfu->dfu_state) {
156 	case DFU_STATE_dfuDNLOAD_SYNC:
157 	case DFU_STATE_dfuDNBUSY:
158 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_IDLE;
159 		break;
160 	case DFU_STATE_dfuMANIFEST_SYNC:
161 		break;
162 	default:
163 		break;
164 	}
165 
166 	/* send status response */
167 	dstat->bStatus = f_dfu->dfu_status;
168 	dstat->bState = f_dfu->dfu_state;
169 	dstat->iString = 0;
170 }
171 
172 static void handle_getstate(struct usb_request *req)
173 {
174 	struct f_dfu *f_dfu = req->context;
175 
176 	((u8 *)req->buf)[0] = f_dfu->dfu_state;
177 	req->actual = sizeof(u8);
178 }
179 
180 static inline void to_dfu_mode(struct f_dfu *f_dfu)
181 {
182 	f_dfu->usb_function.strings = dfu_strings;
183 	f_dfu->usb_function.hs_descriptors = f_dfu->function;
184 }
185 
186 static inline void to_runtime_mode(struct f_dfu *f_dfu)
187 {
188 	f_dfu->usb_function.strings = NULL;
189 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
190 }
191 
192 static int handle_upload(struct usb_request *req, u16 len)
193 {
194 	struct f_dfu *f_dfu = req->context;
195 
196 	return dfu_read(dfu_get_entity(f_dfu->altsetting), req->buf,
197 			req->length, f_dfu->blk_seq_num);
198 }
199 
200 static int handle_dnload(struct usb_gadget *gadget, u16 len)
201 {
202 	struct usb_composite_dev *cdev = get_gadget_data(gadget);
203 	struct usb_request *req = cdev->req;
204 	struct f_dfu *f_dfu = req->context;
205 
206 	if (len == 0)
207 		f_dfu->dfu_state = DFU_STATE_dfuMANIFEST_SYNC;
208 
209 	req->complete = dnload_request_complete;
210 
211 	return len;
212 }
213 
214 /*-------------------------------------------------------------------------*/
215 /* DFU state machine  */
216 static int state_app_idle(struct f_dfu *f_dfu,
217 			  const struct usb_ctrlrequest *ctrl,
218 			  struct usb_gadget *gadget,
219 			  struct usb_request *req)
220 {
221 	int value = 0;
222 
223 	switch (ctrl->bRequest) {
224 	case USB_REQ_DFU_GETSTATUS:
225 		handle_getstatus(req);
226 		value = RET_STAT_LEN;
227 		break;
228 	case USB_REQ_DFU_GETSTATE:
229 		handle_getstate(req);
230 		break;
231 	case USB_REQ_DFU_DETACH:
232 		f_dfu->dfu_state = DFU_STATE_appDETACH;
233 		to_dfu_mode(f_dfu);
234 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
235 		value = RET_ZLP;
236 		break;
237 	default:
238 		value = RET_STALL;
239 		break;
240 	}
241 
242 	return value;
243 }
244 
245 static int state_app_detach(struct f_dfu *f_dfu,
246 			    const struct usb_ctrlrequest *ctrl,
247 			    struct usb_gadget *gadget,
248 			    struct usb_request *req)
249 {
250 	int value = 0;
251 
252 	switch (ctrl->bRequest) {
253 	case USB_REQ_DFU_GETSTATUS:
254 		handle_getstatus(req);
255 		value = RET_STAT_LEN;
256 		break;
257 	case USB_REQ_DFU_GETSTATE:
258 		handle_getstate(req);
259 		break;
260 	default:
261 		f_dfu->dfu_state = DFU_STATE_appIDLE;
262 		value = RET_STALL;
263 		break;
264 	}
265 
266 	return value;
267 }
268 
269 static int state_dfu_idle(struct f_dfu *f_dfu,
270 			  const struct usb_ctrlrequest *ctrl,
271 			  struct usb_gadget *gadget,
272 			  struct usb_request *req)
273 {
274 	u16 w_value = le16_to_cpu(ctrl->wValue);
275 	u16 len = le16_to_cpu(ctrl->wLength);
276 	int value = 0;
277 
278 	switch (ctrl->bRequest) {
279 	case USB_REQ_DFU_DNLOAD:
280 		if (len == 0) {
281 			f_dfu->dfu_state = DFU_STATE_dfuERROR;
282 			value = RET_STALL;
283 			break;
284 		}
285 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
286 		f_dfu->blk_seq_num = w_value;
287 		value = handle_dnload(gadget, len);
288 		break;
289 	case USB_REQ_DFU_UPLOAD:
290 		f_dfu->dfu_state = DFU_STATE_dfuUPLOAD_IDLE;
291 		f_dfu->blk_seq_num = 0;
292 		value = handle_upload(req, len);
293 		break;
294 	case USB_REQ_DFU_ABORT:
295 		/* no zlp? */
296 		value = RET_ZLP;
297 		break;
298 	case USB_REQ_DFU_GETSTATUS:
299 		handle_getstatus(req);
300 		value = RET_STAT_LEN;
301 		break;
302 	case USB_REQ_DFU_GETSTATE:
303 		handle_getstate(req);
304 		break;
305 	case USB_REQ_DFU_DETACH:
306 		/*
307 		 * Proprietary extension: 'detach' from idle mode and
308 		 * get back to runtime mode in case of USB Reset.  As
309 		 * much as I dislike this, we just can't use every USB
310 		 * bus reset to switch back to runtime mode, since at
311 		 * least the Linux USB stack likes to send a number of
312 		 * resets in a row :(
313 		 */
314 		f_dfu->dfu_state =
315 			DFU_STATE_dfuMANIFEST_WAIT_RST;
316 		to_runtime_mode(f_dfu);
317 		f_dfu->dfu_state = DFU_STATE_appIDLE;
318 		break;
319 	default:
320 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
321 		value = RET_STALL;
322 		break;
323 	}
324 
325 	return value;
326 }
327 
328 static int state_dfu_dnload_sync(struct f_dfu *f_dfu,
329 				 const struct usb_ctrlrequest *ctrl,
330 				 struct usb_gadget *gadget,
331 				 struct usb_request *req)
332 {
333 	int value = 0;
334 
335 	switch (ctrl->bRequest) {
336 	case USB_REQ_DFU_GETSTATUS:
337 		handle_getstatus(req);
338 		value = RET_STAT_LEN;
339 		break;
340 	case USB_REQ_DFU_GETSTATE:
341 		handle_getstate(req);
342 		break;
343 	default:
344 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
345 		value = RET_STALL;
346 		break;
347 	}
348 
349 	return value;
350 }
351 
352 static int state_dfu_dnbusy(struct f_dfu *f_dfu,
353 			    const struct usb_ctrlrequest *ctrl,
354 			    struct usb_gadget *gadget,
355 			    struct usb_request *req)
356 {
357 	int value = 0;
358 
359 	switch (ctrl->bRequest) {
360 	case USB_REQ_DFU_GETSTATUS:
361 		handle_getstatus(req);
362 		value = RET_STAT_LEN;
363 		break;
364 	default:
365 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
366 		value = RET_STALL;
367 		break;
368 	}
369 
370 	return value;
371 }
372 
373 static int state_dfu_dnload_idle(struct f_dfu *f_dfu,
374 				 const struct usb_ctrlrequest *ctrl,
375 				 struct usb_gadget *gadget,
376 				 struct usb_request *req)
377 {
378 	u16 w_value = le16_to_cpu(ctrl->wValue);
379 	u16 len = le16_to_cpu(ctrl->wLength);
380 	int value = 0;
381 
382 	switch (ctrl->bRequest) {
383 	case USB_REQ_DFU_DNLOAD:
384 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
385 		f_dfu->blk_seq_num = w_value;
386 		value = handle_dnload(gadget, len);
387 		break;
388 	case USB_REQ_DFU_ABORT:
389 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
390 		value = RET_ZLP;
391 		break;
392 	case USB_REQ_DFU_GETSTATUS:
393 		handle_getstatus(req);
394 		value = RET_STAT_LEN;
395 		break;
396 	case USB_REQ_DFU_GETSTATE:
397 		handle_getstate(req);
398 		break;
399 	default:
400 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
401 		value = RET_STALL;
402 		break;
403 	}
404 
405 	return value;
406 }
407 
408 static int state_dfu_manifest_sync(struct f_dfu *f_dfu,
409 				   const struct usb_ctrlrequest *ctrl,
410 				   struct usb_gadget *gadget,
411 				   struct usb_request *req)
412 {
413 	int value = 0;
414 
415 	switch (ctrl->bRequest) {
416 	case USB_REQ_DFU_GETSTATUS:
417 		/* We're MainfestationTolerant */
418 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
419 		handle_getstatus(req);
420 		f_dfu->blk_seq_num = 0;
421 		value = RET_STAT_LEN;
422 		break;
423 	case USB_REQ_DFU_GETSTATE:
424 		handle_getstate(req);
425 		break;
426 	default:
427 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
428 		value = RET_STALL;
429 		break;
430 	}
431 
432 	return value;
433 }
434 
435 static int state_dfu_upload_idle(struct f_dfu *f_dfu,
436 				 const struct usb_ctrlrequest *ctrl,
437 				 struct usb_gadget *gadget,
438 				 struct usb_request *req)
439 {
440 	u16 w_value = le16_to_cpu(ctrl->wValue);
441 	u16 len = le16_to_cpu(ctrl->wLength);
442 	int value = 0;
443 
444 	switch (ctrl->bRequest) {
445 	case USB_REQ_DFU_UPLOAD:
446 		/* state transition if less data then requested */
447 		f_dfu->blk_seq_num = w_value;
448 		value = handle_upload(req, len);
449 		if (value >= 0 && value < len)
450 			f_dfu->dfu_state = DFU_STATE_dfuIDLE;
451 		break;
452 	case USB_REQ_DFU_ABORT:
453 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
454 		/* no zlp? */
455 		value = RET_ZLP;
456 		break;
457 	case USB_REQ_DFU_GETSTATUS:
458 		handle_getstatus(req);
459 		value = RET_STAT_LEN;
460 		break;
461 	case USB_REQ_DFU_GETSTATE:
462 		handle_getstate(req);
463 		break;
464 	default:
465 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
466 		value = RET_STALL;
467 		break;
468 	}
469 
470 	return value;
471 }
472 
473 static int state_dfu_error(struct f_dfu *f_dfu,
474 				 const struct usb_ctrlrequest *ctrl,
475 				 struct usb_gadget *gadget,
476 				 struct usb_request *req)
477 {
478 	int value = 0;
479 
480 	switch (ctrl->bRequest) {
481 	case USB_REQ_DFU_GETSTATUS:
482 		handle_getstatus(req);
483 		value = RET_STAT_LEN;
484 		break;
485 	case USB_REQ_DFU_GETSTATE:
486 		handle_getstate(req);
487 		break;
488 	case USB_REQ_DFU_CLRSTATUS:
489 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
490 		f_dfu->dfu_status = DFU_STATUS_OK;
491 		/* no zlp? */
492 		value = RET_ZLP;
493 		break;
494 	default:
495 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
496 		value = RET_STALL;
497 		break;
498 	}
499 
500 	return value;
501 }
502 
503 static dfu_state_fn dfu_state[] = {
504 	state_app_idle,          /* DFU_STATE_appIDLE */
505 	state_app_detach,        /* DFU_STATE_appDETACH */
506 	state_dfu_idle,          /* DFU_STATE_dfuIDLE */
507 	state_dfu_dnload_sync,   /* DFU_STATE_dfuDNLOAD_SYNC */
508 	state_dfu_dnbusy,        /* DFU_STATE_dfuDNBUSY */
509 	state_dfu_dnload_idle,   /* DFU_STATE_dfuDNLOAD_IDLE */
510 	state_dfu_manifest_sync, /* DFU_STATE_dfuMANIFEST_SYNC */
511 	NULL,                    /* DFU_STATE_dfuMANIFEST */
512 	NULL,                    /* DFU_STATE_dfuMANIFEST_WAIT_RST */
513 	state_dfu_upload_idle,   /* DFU_STATE_dfuUPLOAD_IDLE */
514 	state_dfu_error          /* DFU_STATE_dfuERROR */
515 };
516 
517 static int
518 dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
519 {
520 	struct usb_gadget *gadget = f->config->cdev->gadget;
521 	struct usb_request *req = f->config->cdev->req;
522 	struct f_dfu *f_dfu = f->config->cdev->req->context;
523 	u16 len = le16_to_cpu(ctrl->wLength);
524 	u16 w_value = le16_to_cpu(ctrl->wValue);
525 	int value = 0;
526 	u8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
527 
528 	debug("w_value: 0x%x len: 0x%x\n", w_value, len);
529 	debug("req_type: 0x%x ctrl->bRequest: 0x%x f_dfu->dfu_state: 0x%x\n",
530 	       req_type, ctrl->bRequest, f_dfu->dfu_state);
531 
532 	if (req_type == USB_TYPE_STANDARD) {
533 		if (ctrl->bRequest == USB_REQ_GET_DESCRIPTOR &&
534 		    (w_value >> 8) == DFU_DT_FUNC) {
535 			value = min(len, (u16) sizeof(dfu_func));
536 			memcpy(req->buf, &dfu_func, value);
537 		}
538 	} else /* DFU specific request */
539 		value = dfu_state[f_dfu->dfu_state] (f_dfu, ctrl, gadget, req);
540 
541 	if (value >= 0) {
542 		req->length = value;
543 		req->zero = value < len;
544 		value = usb_ep_queue(gadget->ep0, req, 0);
545 		if (value < 0) {
546 			debug("ep_queue --> %d\n", value);
547 			req->status = 0;
548 		}
549 	}
550 
551 	return value;
552 }
553 
554 /*-------------------------------------------------------------------------*/
555 
556 static int
557 dfu_prepare_strings(struct f_dfu *f_dfu, int n)
558 {
559 	struct dfu_entity *de = NULL;
560 	int i = 0;
561 
562 	f_dfu->strings = calloc(sizeof(struct usb_string), n + 1);
563 	if (!f_dfu->strings)
564 		goto enomem;
565 
566 	for (i = 0; i < n; ++i) {
567 		de = dfu_get_entity(i);
568 		f_dfu->strings[i].s = de->name;
569 	}
570 
571 	f_dfu->strings[i].id = 0;
572 	f_dfu->strings[i].s = NULL;
573 
574 	return 0;
575 
576 enomem:
577 	while (i)
578 		f_dfu->strings[--i].s = NULL;
579 
580 	free(f_dfu->strings);
581 
582 	return -ENOMEM;
583 }
584 
585 static int dfu_prepare_function(struct f_dfu *f_dfu, int n)
586 {
587 	struct usb_interface_descriptor *d;
588 	int i = 0;
589 
590 	f_dfu->function = calloc(sizeof(struct usb_descriptor_header *), n);
591 	if (!f_dfu->function)
592 		goto enomem;
593 
594 	for (i = 0; i < n; ++i) {
595 		d = calloc(sizeof(*d), 1);
596 		if (!d)
597 			goto enomem;
598 
599 		d->bLength =		sizeof(*d);
600 		d->bDescriptorType =	USB_DT_INTERFACE;
601 		d->bAlternateSetting =	i;
602 		d->bNumEndpoints =	0;
603 		d->bInterfaceClass =	USB_CLASS_APP_SPEC;
604 		d->bInterfaceSubClass =	1;
605 		d->bInterfaceProtocol =	2;
606 
607 		f_dfu->function[i] = (struct usb_descriptor_header *)d;
608 	}
609 	f_dfu->function[i] = NULL;
610 
611 	return 0;
612 
613 enomem:
614 	while (i) {
615 		free(f_dfu->function[--i]);
616 		f_dfu->function[i] = NULL;
617 	}
618 	free(f_dfu->function);
619 
620 	return -ENOMEM;
621 }
622 
623 static int dfu_bind(struct usb_configuration *c, struct usb_function *f)
624 {
625 	struct usb_composite_dev *cdev = c->cdev;
626 	struct f_dfu *f_dfu = func_to_dfu(f);
627 	int alt_num = dfu_get_alt_number();
628 	int rv, id, i;
629 
630 	id = usb_interface_id(c, f);
631 	if (id < 0)
632 		return id;
633 	dfu_intf_runtime.bInterfaceNumber = id;
634 
635 	f_dfu->dfu_state = DFU_STATE_appIDLE;
636 	f_dfu->dfu_status = DFU_STATUS_OK;
637 
638 	rv = dfu_prepare_function(f_dfu, alt_num);
639 	if (rv)
640 		goto error;
641 
642 	rv = dfu_prepare_strings(f_dfu, alt_num);
643 	if (rv)
644 		goto error;
645 	for (i = 0; i < alt_num; i++) {
646 		id = usb_string_id(cdev);
647 		if (id < 0)
648 			return id;
649 		f_dfu->strings[i].id = id;
650 		((struct usb_interface_descriptor *)f_dfu->function[i])
651 			->iInterface = id;
652 	}
653 
654 	stringtab_dfu.strings = f_dfu->strings;
655 
656 	cdev->req->context = f_dfu;
657 
658 error:
659 	return rv;
660 }
661 
662 static void dfu_unbind(struct usb_configuration *c, struct usb_function *f)
663 {
664 	struct f_dfu *f_dfu = func_to_dfu(f);
665 	int alt_num = dfu_get_alt_number();
666 	int i;
667 
668 	if (f_dfu->strings) {
669 		i = alt_num;
670 		while (i)
671 			f_dfu->strings[--i].s = NULL;
672 
673 		free(f_dfu->strings);
674 	}
675 
676 	if (f_dfu->function) {
677 		i = alt_num;
678 		while (i) {
679 			free(f_dfu->function[--i]);
680 			f_dfu->function[i] = NULL;
681 		}
682 		free(f_dfu->function);
683 	}
684 
685 	free(f_dfu);
686 }
687 
688 static int dfu_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
689 {
690 	struct f_dfu *f_dfu = func_to_dfu(f);
691 
692 	debug("%s: intf:%d alt:%d\n", __func__, intf, alt);
693 
694 	f_dfu->altsetting = alt;
695 
696 	return 0;
697 }
698 
699 /* TODO: is this really what we need here? */
700 static void dfu_disable(struct usb_function *f)
701 {
702 	struct f_dfu *f_dfu = func_to_dfu(f);
703 	if (f_dfu->config == 0)
704 		return;
705 
706 	debug("%s: reset config\n", __func__);
707 
708 	f_dfu->config = 0;
709 }
710 
711 static int dfu_bind_config(struct usb_configuration *c)
712 {
713 	struct f_dfu *f_dfu;
714 	int status;
715 
716 	f_dfu = calloc(sizeof(*f_dfu), 1);
717 	if (!f_dfu)
718 		return -ENOMEM;
719 	f_dfu->usb_function.name = "dfu";
720 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
721 	f_dfu->usb_function.bind = dfu_bind;
722 	f_dfu->usb_function.unbind = dfu_unbind;
723 	f_dfu->usb_function.set_alt = dfu_set_alt;
724 	f_dfu->usb_function.disable = dfu_disable;
725 	f_dfu->usb_function.strings = dfu_generic_strings,
726 	f_dfu->usb_function.setup = dfu_handle,
727 
728 	status = usb_add_function(c, &f_dfu->usb_function);
729 	if (status)
730 		free(f_dfu);
731 
732 	return status;
733 }
734 
735 int dfu_add(struct usb_configuration *c)
736 {
737 	int id;
738 
739 	id = usb_string_id(c->cdev);
740 	if (id < 0)
741 		return id;
742 	strings_dfu_generic[0].id = id;
743 	dfu_intf_runtime.iInterface = id;
744 
745 	debug("%s: cdev: 0x%p gadget:0x%p gadget->ep0: 0x%p\n", __func__,
746 	       c->cdev, c->cdev->gadget, c->cdev->gadget->ep0);
747 
748 	return dfu_bind_config(c);
749 }
750