xref: /openbmc/u-boot/drivers/usb/gadget/f_dfu.c (revision da384a9d)
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 <g_dnl.h>
28 #include "f_dfu.h"
29 
30 struct f_dfu {
31 	struct usb_function		usb_function;
32 
33 	struct usb_descriptor_header	**function;
34 	struct usb_string		*strings;
35 
36 	/* when configured, we have one config */
37 	u8				config;
38 	u8				altsetting;
39 	enum dfu_state			dfu_state;
40 	unsigned int			dfu_status;
41 
42 	/* Send/received block number is handy for data integrity check */
43 	int                             blk_seq_num;
44 	unsigned int                    poll_timeout;
45 };
46 
47 typedef int (*dfu_state_fn) (struct f_dfu *,
48 			     const struct usb_ctrlrequest *,
49 			     struct usb_gadget *,
50 			     struct usb_request *);
51 
52 static inline struct f_dfu *func_to_dfu(struct usb_function *f)
53 {
54 	return container_of(f, struct f_dfu, usb_function);
55 }
56 
57 static const struct dfu_function_descriptor dfu_func = {
58 	.bLength =		sizeof dfu_func,
59 	.bDescriptorType =	DFU_DT_FUNC,
60 	.bmAttributes =		DFU_BIT_WILL_DETACH |
61 				DFU_BIT_MANIFESTATION_TOLERANT |
62 				DFU_BIT_CAN_UPLOAD |
63 				DFU_BIT_CAN_DNLOAD,
64 	.wDetachTimeOut =	0,
65 	.wTransferSize =	DFU_USB_BUFSIZ,
66 	.bcdDFUVersion =	__constant_cpu_to_le16(0x0110),
67 };
68 
69 static struct usb_interface_descriptor dfu_intf_runtime = {
70 	.bLength =		sizeof dfu_intf_runtime,
71 	.bDescriptorType =	USB_DT_INTERFACE,
72 	.bNumEndpoints =	0,
73 	.bInterfaceClass =	USB_CLASS_APP_SPEC,
74 	.bInterfaceSubClass =	1,
75 	.bInterfaceProtocol =	1,
76 	/* .iInterface = DYNAMIC */
77 };
78 
79 static struct usb_descriptor_header *dfu_runtime_descs[] = {
80 	(struct usb_descriptor_header *) &dfu_intf_runtime,
81 	NULL,
82 };
83 
84 static const struct usb_qualifier_descriptor dev_qualifier = {
85 	.bLength =		sizeof dev_qualifier,
86 	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
87 	.bcdUSB =		__constant_cpu_to_le16(0x0200),
88 	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
89 	.bNumConfigurations =	1,
90 };
91 
92 static const char dfu_name[] = "Device Firmware Upgrade";
93 
94 /*
95  * static strings, in UTF-8
96  *
97  * dfu_generic configuration
98  */
99 static struct usb_string strings_dfu_generic[] = {
100 	[0].s = dfu_name,
101 	{  }			/* end of list */
102 };
103 
104 static struct usb_gadget_strings stringtab_dfu_generic = {
105 	.language	= 0x0409,	/* en-us */
106 	.strings	= strings_dfu_generic,
107 };
108 
109 static struct usb_gadget_strings *dfu_generic_strings[] = {
110 	&stringtab_dfu_generic,
111 	NULL,
112 };
113 
114 /*
115  * usb_function specific
116  */
117 static struct usb_gadget_strings stringtab_dfu = {
118 	.language	= 0x0409,	/* en-us */
119 	/*
120 	 * .strings
121 	 *
122 	 * assigned during initialization,
123 	 * depends on number of flash entities
124 	 *
125 	 */
126 };
127 
128 static struct usb_gadget_strings *dfu_strings[] = {
129 	&stringtab_dfu,
130 	NULL,
131 };
132 
133 static void dfu_set_poll_timeout(struct dfu_status *dstat, unsigned int ms)
134 {
135 	/*
136 	 * The bwPollTimeout DFU_GETSTATUS request payload provides information
137 	 * about minimum time, in milliseconds, that the host should wait before
138 	 * sending a subsequent DFU_GETSTATUS request
139 	 *
140 	 * This permits the device to vary the delay depending on its need to
141 	 * erase or program the memory
142 	 *
143 	 */
144 
145 	unsigned char *p = (unsigned char *)&ms;
146 
147 	if (!ms || (ms & ~DFU_POLL_TIMEOUT_MASK)) {
148 		dstat->bwPollTimeout[0] = 0;
149 		dstat->bwPollTimeout[1] = 0;
150 		dstat->bwPollTimeout[2] = 0;
151 
152 		return;
153 	}
154 
155 	dstat->bwPollTimeout[0] = *p++;
156 	dstat->bwPollTimeout[1] = *p++;
157 	dstat->bwPollTimeout[2] = *p;
158 }
159 
160 /*-------------------------------------------------------------------------*/
161 
162 static void dnload_request_complete(struct usb_ep *ep, struct usb_request *req)
163 {
164 	struct f_dfu *f_dfu = req->context;
165 
166 	dfu_write(dfu_get_entity(f_dfu->altsetting), req->buf,
167 		  req->length, f_dfu->blk_seq_num);
168 }
169 
170 static void dnload_request_flush(struct usb_ep *ep, struct usb_request *req)
171 {
172 	struct f_dfu *f_dfu = req->context;
173 
174 	dfu_flush(dfu_get_entity(f_dfu->altsetting), req->buf,
175 		  req->length, f_dfu->blk_seq_num);
176 }
177 
178 static void handle_getstatus(struct usb_request *req)
179 {
180 	struct dfu_status *dstat = (struct dfu_status *)req->buf;
181 	struct f_dfu *f_dfu = req->context;
182 
183 	dfu_set_poll_timeout(dstat, 0);
184 
185 	switch (f_dfu->dfu_state) {
186 	case DFU_STATE_dfuDNLOAD_SYNC:
187 	case DFU_STATE_dfuDNBUSY:
188 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_IDLE;
189 		break;
190 	case DFU_STATE_dfuMANIFEST_SYNC:
191 		f_dfu->dfu_state = DFU_STATE_dfuMANIFEST;
192 		break;
193 	case DFU_STATE_dfuMANIFEST:
194 		dfu_set_poll_timeout(dstat, DFU_MANIFEST_POLL_TIMEOUT);
195 	default:
196 		break;
197 	}
198 
199 	if (f_dfu->poll_timeout)
200 		if (!(f_dfu->blk_seq_num %
201 		      (dfu_get_buf_size() / DFU_USB_BUFSIZ)))
202 			dfu_set_poll_timeout(dstat, f_dfu->poll_timeout);
203 
204 	/* send status response */
205 	dstat->bStatus = f_dfu->dfu_status;
206 	dstat->bState = f_dfu->dfu_state;
207 	dstat->iString = 0;
208 }
209 
210 static void handle_getstate(struct usb_request *req)
211 {
212 	struct f_dfu *f_dfu = req->context;
213 
214 	((u8 *)req->buf)[0] = f_dfu->dfu_state;
215 	req->actual = sizeof(u8);
216 }
217 
218 static inline void to_dfu_mode(struct f_dfu *f_dfu)
219 {
220 	f_dfu->usb_function.strings = dfu_strings;
221 	f_dfu->usb_function.hs_descriptors = f_dfu->function;
222 	f_dfu->dfu_state = DFU_STATE_dfuIDLE;
223 }
224 
225 static inline void to_runtime_mode(struct f_dfu *f_dfu)
226 {
227 	f_dfu->usb_function.strings = NULL;
228 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
229 }
230 
231 static int handle_upload(struct usb_request *req, u16 len)
232 {
233 	struct f_dfu *f_dfu = req->context;
234 
235 	return dfu_read(dfu_get_entity(f_dfu->altsetting), req->buf,
236 			req->length, f_dfu->blk_seq_num);
237 }
238 
239 static int handle_dnload(struct usb_gadget *gadget, u16 len)
240 {
241 	struct usb_composite_dev *cdev = get_gadget_data(gadget);
242 	struct usb_request *req = cdev->req;
243 	struct f_dfu *f_dfu = req->context;
244 
245 	if (len == 0)
246 		f_dfu->dfu_state = DFU_STATE_dfuMANIFEST_SYNC;
247 
248 	req->complete = dnload_request_complete;
249 
250 	return len;
251 }
252 
253 /*-------------------------------------------------------------------------*/
254 /* DFU state machine  */
255 static int state_app_idle(struct f_dfu *f_dfu,
256 			  const struct usb_ctrlrequest *ctrl,
257 			  struct usb_gadget *gadget,
258 			  struct usb_request *req)
259 {
260 	int value = 0;
261 
262 	switch (ctrl->bRequest) {
263 	case USB_REQ_DFU_GETSTATUS:
264 		handle_getstatus(req);
265 		value = RET_STAT_LEN;
266 		break;
267 	case USB_REQ_DFU_GETSTATE:
268 		handle_getstate(req);
269 		break;
270 	case USB_REQ_DFU_DETACH:
271 		f_dfu->dfu_state = DFU_STATE_appDETACH;
272 		to_dfu_mode(f_dfu);
273 		value = RET_ZLP;
274 		break;
275 	default:
276 		value = RET_STALL;
277 		break;
278 	}
279 
280 	return value;
281 }
282 
283 static int state_app_detach(struct f_dfu *f_dfu,
284 			    const struct usb_ctrlrequest *ctrl,
285 			    struct usb_gadget *gadget,
286 			    struct usb_request *req)
287 {
288 	int value = 0;
289 
290 	switch (ctrl->bRequest) {
291 	case USB_REQ_DFU_GETSTATUS:
292 		handle_getstatus(req);
293 		value = RET_STAT_LEN;
294 		break;
295 	case USB_REQ_DFU_GETSTATE:
296 		handle_getstate(req);
297 		break;
298 	default:
299 		f_dfu->dfu_state = DFU_STATE_appIDLE;
300 		value = RET_STALL;
301 		break;
302 	}
303 
304 	return value;
305 }
306 
307 static int state_dfu_idle(struct f_dfu *f_dfu,
308 			  const struct usb_ctrlrequest *ctrl,
309 			  struct usb_gadget *gadget,
310 			  struct usb_request *req)
311 {
312 	u16 w_value = le16_to_cpu(ctrl->wValue);
313 	u16 len = le16_to_cpu(ctrl->wLength);
314 	int value = 0;
315 
316 	switch (ctrl->bRequest) {
317 	case USB_REQ_DFU_DNLOAD:
318 		if (len == 0) {
319 			f_dfu->dfu_state = DFU_STATE_dfuERROR;
320 			value = RET_STALL;
321 			break;
322 		}
323 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
324 		f_dfu->blk_seq_num = w_value;
325 		value = handle_dnload(gadget, len);
326 		break;
327 	case USB_REQ_DFU_UPLOAD:
328 		f_dfu->dfu_state = DFU_STATE_dfuUPLOAD_IDLE;
329 		f_dfu->blk_seq_num = 0;
330 		value = handle_upload(req, len);
331 		break;
332 	case USB_REQ_DFU_ABORT:
333 		/* no zlp? */
334 		value = RET_ZLP;
335 		break;
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 	case USB_REQ_DFU_DETACH:
344 		/*
345 		 * Proprietary extension: 'detach' from idle mode and
346 		 * get back to runtime mode in case of USB Reset.  As
347 		 * much as I dislike this, we just can't use every USB
348 		 * bus reset to switch back to runtime mode, since at
349 		 * least the Linux USB stack likes to send a number of
350 		 * resets in a row :(
351 		 */
352 		f_dfu->dfu_state =
353 			DFU_STATE_dfuMANIFEST_WAIT_RST;
354 		to_runtime_mode(f_dfu);
355 		f_dfu->dfu_state = DFU_STATE_appIDLE;
356 
357 		dfu_trigger_reset();
358 		break;
359 	default:
360 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
361 		value = RET_STALL;
362 		break;
363 	}
364 
365 	return value;
366 }
367 
368 static int state_dfu_dnload_sync(struct f_dfu *f_dfu,
369 				 const struct usb_ctrlrequest *ctrl,
370 				 struct usb_gadget *gadget,
371 				 struct usb_request *req)
372 {
373 	int value = 0;
374 
375 	switch (ctrl->bRequest) {
376 	case USB_REQ_DFU_GETSTATUS:
377 		handle_getstatus(req);
378 		value = RET_STAT_LEN;
379 		break;
380 	case USB_REQ_DFU_GETSTATE:
381 		handle_getstate(req);
382 		break;
383 	default:
384 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
385 		value = RET_STALL;
386 		break;
387 	}
388 
389 	return value;
390 }
391 
392 static int state_dfu_dnbusy(struct f_dfu *f_dfu,
393 			    const struct usb_ctrlrequest *ctrl,
394 			    struct usb_gadget *gadget,
395 			    struct usb_request *req)
396 {
397 	int value = 0;
398 
399 	switch (ctrl->bRequest) {
400 	case USB_REQ_DFU_GETSTATUS:
401 		handle_getstatus(req);
402 		value = RET_STAT_LEN;
403 		break;
404 	default:
405 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
406 		value = RET_STALL;
407 		break;
408 	}
409 
410 	return value;
411 }
412 
413 static int state_dfu_dnload_idle(struct f_dfu *f_dfu,
414 				 const struct usb_ctrlrequest *ctrl,
415 				 struct usb_gadget *gadget,
416 				 struct usb_request *req)
417 {
418 	u16 w_value = le16_to_cpu(ctrl->wValue);
419 	u16 len = le16_to_cpu(ctrl->wLength);
420 	int value = 0;
421 
422 	switch (ctrl->bRequest) {
423 	case USB_REQ_DFU_DNLOAD:
424 		f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC;
425 		f_dfu->blk_seq_num = w_value;
426 		value = handle_dnload(gadget, len);
427 		break;
428 	case USB_REQ_DFU_ABORT:
429 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
430 		value = RET_ZLP;
431 		break;
432 	case USB_REQ_DFU_GETSTATUS:
433 		handle_getstatus(req);
434 		value = RET_STAT_LEN;
435 		break;
436 	case USB_REQ_DFU_GETSTATE:
437 		handle_getstate(req);
438 		break;
439 	default:
440 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
441 		value = RET_STALL;
442 		break;
443 	}
444 
445 	return value;
446 }
447 
448 static int state_dfu_manifest_sync(struct f_dfu *f_dfu,
449 				   const struct usb_ctrlrequest *ctrl,
450 				   struct usb_gadget *gadget,
451 				   struct usb_request *req)
452 {
453 	int value = 0;
454 
455 	switch (ctrl->bRequest) {
456 	case USB_REQ_DFU_GETSTATUS:
457 		/* We're MainfestationTolerant */
458 		f_dfu->dfu_state = DFU_STATE_dfuMANIFEST;
459 		handle_getstatus(req);
460 		f_dfu->blk_seq_num = 0;
461 		value = RET_STAT_LEN;
462 		req->complete = dnload_request_flush;
463 		break;
464 	case USB_REQ_DFU_GETSTATE:
465 		handle_getstate(req);
466 		break;
467 	default:
468 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
469 		value = RET_STALL;
470 		break;
471 	}
472 
473 	return value;
474 }
475 
476 static int state_dfu_manifest(struct f_dfu *f_dfu,
477 			      const struct usb_ctrlrequest *ctrl,
478 			      struct usb_gadget *gadget,
479 			      struct usb_request *req)
480 {
481 	int value = 0;
482 
483 	switch (ctrl->bRequest) {
484 	case USB_REQ_DFU_GETSTATUS:
485 		/* We're MainfestationTolerant */
486 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
487 		handle_getstatus(req);
488 		f_dfu->blk_seq_num = 0;
489 		value = RET_STAT_LEN;
490 		puts("DOWNLOAD ... OK\nCtrl+C to exit ...\n");
491 		break;
492 	case USB_REQ_DFU_GETSTATE:
493 		handle_getstate(req);
494 		break;
495 	default:
496 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
497 		value = RET_STALL;
498 		break;
499 	}
500 	return value;
501 }
502 
503 static int state_dfu_upload_idle(struct f_dfu *f_dfu,
504 				 const struct usb_ctrlrequest *ctrl,
505 				 struct usb_gadget *gadget,
506 				 struct usb_request *req)
507 {
508 	u16 w_value = le16_to_cpu(ctrl->wValue);
509 	u16 len = le16_to_cpu(ctrl->wLength);
510 	int value = 0;
511 
512 	switch (ctrl->bRequest) {
513 	case USB_REQ_DFU_UPLOAD:
514 		/* state transition if less data then requested */
515 		f_dfu->blk_seq_num = w_value;
516 		value = handle_upload(req, len);
517 		if (value >= 0 && value < len)
518 			f_dfu->dfu_state = DFU_STATE_dfuIDLE;
519 		break;
520 	case USB_REQ_DFU_ABORT:
521 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
522 		/* no zlp? */
523 		value = RET_ZLP;
524 		break;
525 	case USB_REQ_DFU_GETSTATUS:
526 		handle_getstatus(req);
527 		value = RET_STAT_LEN;
528 		break;
529 	case USB_REQ_DFU_GETSTATE:
530 		handle_getstate(req);
531 		break;
532 	default:
533 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
534 		value = RET_STALL;
535 		break;
536 	}
537 
538 	return value;
539 }
540 
541 static int state_dfu_error(struct f_dfu *f_dfu,
542 				 const struct usb_ctrlrequest *ctrl,
543 				 struct usb_gadget *gadget,
544 				 struct usb_request *req)
545 {
546 	int value = 0;
547 
548 	switch (ctrl->bRequest) {
549 	case USB_REQ_DFU_GETSTATUS:
550 		handle_getstatus(req);
551 		value = RET_STAT_LEN;
552 		break;
553 	case USB_REQ_DFU_GETSTATE:
554 		handle_getstate(req);
555 		break;
556 	case USB_REQ_DFU_CLRSTATUS:
557 		f_dfu->dfu_state = DFU_STATE_dfuIDLE;
558 		f_dfu->dfu_status = DFU_STATUS_OK;
559 		/* no zlp? */
560 		value = RET_ZLP;
561 		break;
562 	default:
563 		f_dfu->dfu_state = DFU_STATE_dfuERROR;
564 		value = RET_STALL;
565 		break;
566 	}
567 
568 	return value;
569 }
570 
571 static dfu_state_fn dfu_state[] = {
572 	state_app_idle,          /* DFU_STATE_appIDLE */
573 	state_app_detach,        /* DFU_STATE_appDETACH */
574 	state_dfu_idle,          /* DFU_STATE_dfuIDLE */
575 	state_dfu_dnload_sync,   /* DFU_STATE_dfuDNLOAD_SYNC */
576 	state_dfu_dnbusy,        /* DFU_STATE_dfuDNBUSY */
577 	state_dfu_dnload_idle,   /* DFU_STATE_dfuDNLOAD_IDLE */
578 	state_dfu_manifest_sync, /* DFU_STATE_dfuMANIFEST_SYNC */
579 	state_dfu_manifest,	 /* DFU_STATE_dfuMANIFEST */
580 	NULL,                    /* DFU_STATE_dfuMANIFEST_WAIT_RST */
581 	state_dfu_upload_idle,   /* DFU_STATE_dfuUPLOAD_IDLE */
582 	state_dfu_error          /* DFU_STATE_dfuERROR */
583 };
584 
585 static int
586 dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
587 {
588 	struct usb_gadget *gadget = f->config->cdev->gadget;
589 	struct usb_request *req = f->config->cdev->req;
590 	struct f_dfu *f_dfu = f->config->cdev->req->context;
591 	u16 len = le16_to_cpu(ctrl->wLength);
592 	u16 w_value = le16_to_cpu(ctrl->wValue);
593 	int value = 0;
594 	u8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
595 
596 	debug("w_value: 0x%x len: 0x%x\n", w_value, len);
597 	debug("req_type: 0x%x ctrl->bRequest: 0x%x f_dfu->dfu_state: 0x%x\n",
598 	       req_type, ctrl->bRequest, f_dfu->dfu_state);
599 
600 	if (req_type == USB_TYPE_STANDARD) {
601 		if (ctrl->bRequest == USB_REQ_GET_DESCRIPTOR &&
602 		    (w_value >> 8) == DFU_DT_FUNC) {
603 			value = min(len, (u16) sizeof(dfu_func));
604 			memcpy(req->buf, &dfu_func, value);
605 		}
606 	} else /* DFU specific request */
607 		value = dfu_state[f_dfu->dfu_state] (f_dfu, ctrl, gadget, req);
608 
609 	if (value >= 0) {
610 		req->length = value;
611 		req->zero = value < len;
612 		value = usb_ep_queue(gadget->ep0, req, 0);
613 		if (value < 0) {
614 			debug("ep_queue --> %d\n", value);
615 			req->status = 0;
616 		}
617 	}
618 
619 	return value;
620 }
621 
622 /*-------------------------------------------------------------------------*/
623 
624 static int
625 dfu_prepare_strings(struct f_dfu *f_dfu, int n)
626 {
627 	struct dfu_entity *de = NULL;
628 	int i = 0;
629 
630 	f_dfu->strings = calloc(sizeof(struct usb_string), n + 1);
631 	if (!f_dfu->strings)
632 		goto enomem;
633 
634 	for (i = 0; i < n; ++i) {
635 		de = dfu_get_entity(i);
636 		f_dfu->strings[i].s = de->name;
637 	}
638 
639 	f_dfu->strings[i].id = 0;
640 	f_dfu->strings[i].s = NULL;
641 
642 	return 0;
643 
644 enomem:
645 	while (i)
646 		f_dfu->strings[--i].s = NULL;
647 
648 	free(f_dfu->strings);
649 
650 	return -ENOMEM;
651 }
652 
653 static int dfu_prepare_function(struct f_dfu *f_dfu, int n)
654 {
655 	struct usb_interface_descriptor *d;
656 	int i = 0;
657 
658 	f_dfu->function = calloc(sizeof(struct usb_descriptor_header *), n + 1);
659 	if (!f_dfu->function)
660 		goto enomem;
661 
662 	for (i = 0; i < n; ++i) {
663 		d = calloc(sizeof(*d), 1);
664 		if (!d)
665 			goto enomem;
666 
667 		d->bLength =		sizeof(*d);
668 		d->bDescriptorType =	USB_DT_INTERFACE;
669 		d->bAlternateSetting =	i;
670 		d->bNumEndpoints =	0;
671 		d->bInterfaceClass =	USB_CLASS_APP_SPEC;
672 		d->bInterfaceSubClass =	1;
673 		d->bInterfaceProtocol =	2;
674 
675 		f_dfu->function[i] = (struct usb_descriptor_header *)d;
676 	}
677 	f_dfu->function[i] = NULL;
678 
679 	return 0;
680 
681 enomem:
682 	while (i) {
683 		free(f_dfu->function[--i]);
684 		f_dfu->function[i] = NULL;
685 	}
686 	free(f_dfu->function);
687 
688 	return -ENOMEM;
689 }
690 
691 static int dfu_bind(struct usb_configuration *c, struct usb_function *f)
692 {
693 	struct usb_composite_dev *cdev = c->cdev;
694 	struct f_dfu *f_dfu = func_to_dfu(f);
695 	int alt_num = dfu_get_alt_number();
696 	int rv, id, i;
697 
698 	id = usb_interface_id(c, f);
699 	if (id < 0)
700 		return id;
701 	dfu_intf_runtime.bInterfaceNumber = id;
702 
703 	f_dfu->dfu_state = DFU_STATE_appIDLE;
704 	f_dfu->dfu_status = DFU_STATUS_OK;
705 
706 	rv = dfu_prepare_function(f_dfu, alt_num);
707 	if (rv)
708 		goto error;
709 
710 	rv = dfu_prepare_strings(f_dfu, alt_num);
711 	if (rv)
712 		goto error;
713 	for (i = 0; i < alt_num; i++) {
714 		id = usb_string_id(cdev);
715 		if (id < 0)
716 			return id;
717 		f_dfu->strings[i].id = id;
718 		((struct usb_interface_descriptor *)f_dfu->function[i])
719 			->iInterface = id;
720 	}
721 
722 	to_dfu_mode(f_dfu);
723 
724 	stringtab_dfu.strings = f_dfu->strings;
725 
726 	cdev->req->context = f_dfu;
727 
728 error:
729 	return rv;
730 }
731 
732 static void dfu_unbind(struct usb_configuration *c, struct usb_function *f)
733 {
734 	struct f_dfu *f_dfu = func_to_dfu(f);
735 	int alt_num = dfu_get_alt_number();
736 	int i;
737 
738 	if (f_dfu->strings) {
739 		i = alt_num;
740 		while (i)
741 			f_dfu->strings[--i].s = NULL;
742 
743 		free(f_dfu->strings);
744 	}
745 
746 	if (f_dfu->function) {
747 		i = alt_num;
748 		while (i) {
749 			free(f_dfu->function[--i]);
750 			f_dfu->function[i] = NULL;
751 		}
752 		free(f_dfu->function);
753 	}
754 
755 	free(f_dfu);
756 }
757 
758 static int dfu_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
759 {
760 	struct f_dfu *f_dfu = func_to_dfu(f);
761 
762 	debug("%s: intf:%d alt:%d\n", __func__, intf, alt);
763 
764 	f_dfu->altsetting = alt;
765 
766 	return 0;
767 }
768 
769 /* TODO: is this really what we need here? */
770 static void dfu_disable(struct usb_function *f)
771 {
772 	struct f_dfu *f_dfu = func_to_dfu(f);
773 	if (f_dfu->config == 0)
774 		return;
775 
776 	debug("%s: reset config\n", __func__);
777 
778 	f_dfu->config = 0;
779 }
780 
781 static int dfu_bind_config(struct usb_configuration *c)
782 {
783 	struct f_dfu *f_dfu;
784 	int status;
785 
786 	f_dfu = calloc(sizeof(*f_dfu), 1);
787 	if (!f_dfu)
788 		return -ENOMEM;
789 	f_dfu->usb_function.name = "dfu";
790 	f_dfu->usb_function.hs_descriptors = dfu_runtime_descs;
791 	f_dfu->usb_function.bind = dfu_bind;
792 	f_dfu->usb_function.unbind = dfu_unbind;
793 	f_dfu->usb_function.set_alt = dfu_set_alt;
794 	f_dfu->usb_function.disable = dfu_disable;
795 	f_dfu->usb_function.strings = dfu_generic_strings;
796 	f_dfu->usb_function.setup = dfu_handle;
797 	f_dfu->poll_timeout = DFU_DEFAULT_POLL_TIMEOUT;
798 
799 	status = usb_add_function(c, &f_dfu->usb_function);
800 	if (status)
801 		free(f_dfu);
802 
803 	return status;
804 }
805 
806 int dfu_add(struct usb_configuration *c)
807 {
808 	int id;
809 
810 	id = usb_string_id(c->cdev);
811 	if (id < 0)
812 		return id;
813 	strings_dfu_generic[0].id = id;
814 	dfu_intf_runtime.iInterface = id;
815 
816 	debug("%s: cdev: 0x%p gadget:0x%p gadget->ep0: 0x%p\n", __func__,
817 	       c->cdev, c->cdev->gadget, c->cdev->gadget->ep0);
818 
819 	return dfu_bind_config(c);
820 }
821 
822 DECLARE_GADGET_BIND_CALLBACK(usb_dnl_dfu, dfu_add);
823