xref: /openbmc/u-boot/drivers/usb/gadget/f_sdp.c (revision 12308b12)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * f_sdp.c -- USB HID Serial Download Protocol
4  *
5  * Copyright (C) 2017 Toradex
6  * Author: Stefan Agner <stefan.agner@toradex.com>
7  *
8  * This file implements the Serial Download Protocol (SDP) as specified in
9  * the i.MX 6 Reference Manual. The SDP is a USB HID based protocol and
10  * allows to download images directly to memory. The implementation
11  * works with the imx_loader (imx_usb) USB client software on host side.
12  *
13  * Not all commands are implemented, e.g. WRITE_REGISTER, DCD_WRITE and
14  * SKIP_DCD_HEADER are only stubs.
15  *
16  * Parts of the implementation are based on f_dfu and f_thor.
17  */
18 
19 #include <errno.h>
20 #include <common.h>
21 #include <console.h>
22 #include <malloc.h>
23 
24 #include <linux/usb/ch9.h>
25 #include <linux/usb/gadget.h>
26 #include <linux/usb/composite.h>
27 
28 #include <asm/io.h>
29 #include <g_dnl.h>
30 #include <sdp.h>
31 #include <spl.h>
32 #include <image.h>
33 #include <imximage.h>
34 #include <watchdog.h>
35 
36 #define HID_REPORT_ID_MASK	0x000000ff
37 
38 /*
39  * HID class requests
40  */
41 #define HID_REQ_GET_REPORT		0x01
42 #define HID_REQ_GET_IDLE		0x02
43 #define HID_REQ_GET_PROTOCOL		0x03
44 #define HID_REQ_SET_REPORT		0x09
45 #define HID_REQ_SET_IDLE		0x0A
46 #define HID_REQ_SET_PROTOCOL		0x0B
47 
48 #define HID_USAGE_PAGE_LEN		76
49 
50 struct hid_report {
51 	u8 usage_page[HID_USAGE_PAGE_LEN];
52 } __packed;
53 
54 #define SDP_READ_REGISTER	0x0101
55 #define SDP_WRITE_REGISTER	0x0202
56 #define SDP_WRITE_FILE		0x0404
57 #define SDP_ERROR_STATUS	0x0505
58 #define SDP_DCD_WRITE		0x0a0a
59 #define SDP_JUMP_ADDRESS	0x0b0b
60 #define SDP_SKIP_DCD_HEADER	0x0c0c
61 
62 #define SDP_SECURITY_CLOSED		0x12343412
63 #define SDP_SECURITY_OPEN		0x56787856
64 
65 #define SDP_WRITE_FILE_COMPLETE		0x88888888
66 #define SDP_WRITE_REGISTER_COMPLETE	0x128A8A12
67 #define SDP_SKIP_DCD_HEADER_COMPLETE	0x900DD009
68 #define SDP_ERROR_IMXHEADER		0x000a0533
69 
70 #define SDP_COMMAND_LEN		16
71 
72 struct sdp_command {
73 	u16 cmd;
74 	u32 addr;
75 	u8 format;
76 	u32 cnt;
77 	u32 data;
78 	u8 rsvd;
79 } __packed;
80 
81 enum sdp_state {
82 	SDP_STATE_IDLE,
83 	SDP_STATE_RX_DCD_DATA,
84 	SDP_STATE_RX_FILE_DATA,
85 	SDP_STATE_TX_SEC_CONF,
86 	SDP_STATE_TX_SEC_CONF_BUSY,
87 	SDP_STATE_TX_REGISTER,
88 	SDP_STATE_TX_REGISTER_BUSY,
89 	SDP_STATE_TX_STATUS,
90 	SDP_STATE_TX_STATUS_BUSY,
91 	SDP_STATE_JUMP,
92 };
93 
94 struct f_sdp {
95 	struct usb_function		usb_function;
96 
97 	struct usb_descriptor_header	**function;
98 
99 	u8				altsetting;
100 	enum sdp_state			state;
101 	enum sdp_state			next_state;
102 	u32				dnl_address;
103 	u32				dnl_bytes_remaining;
104 	u32				jmp_address;
105 	bool				always_send_status;
106 	u32				error_status;
107 
108 	/* EP0 request */
109 	struct usb_request		*req;
110 
111 	/* EP1 IN */
112 	struct usb_ep			*in_ep;
113 	struct usb_request		*in_req;
114 
115 	bool				configuration_done;
116 };
117 
118 static struct f_sdp *sdp_func;
119 
120 static inline struct f_sdp *func_to_sdp(struct usb_function *f)
121 {
122 	return container_of(f, struct f_sdp, usb_function);
123 }
124 
125 static struct usb_interface_descriptor sdp_intf_runtime = {
126 	.bLength =		sizeof(sdp_intf_runtime),
127 	.bDescriptorType =	USB_DT_INTERFACE,
128 	.bAlternateSetting =	0,
129 	.bNumEndpoints =	1,
130 	.bInterfaceClass =	USB_CLASS_HID,
131 	.bInterfaceSubClass =	0,
132 	.bInterfaceProtocol =	0,
133 	/* .iInterface = DYNAMIC */
134 };
135 
136 /* HID configuration */
137 static struct usb_class_hid_descriptor sdp_hid_desc = {
138 	.bLength =		sizeof(sdp_hid_desc),
139 	.bDescriptorType =	USB_DT_CS_DEVICE,
140 
141 	.bcdCDC =		__constant_cpu_to_le16(0x0110),
142 	.bCountryCode =		0,
143 	.bNumDescriptors =	1,
144 
145 	.bDescriptorType0	= USB_DT_HID_REPORT,
146 	.wDescriptorLength0	= HID_USAGE_PAGE_LEN,
147 };
148 
149 static struct usb_endpoint_descriptor in_desc = {
150 	.bLength =		USB_DT_ENDPOINT_SIZE,
151 	.bDescriptorType =	USB_DT_ENDPOINT, /*USB_DT_CS_ENDPOINT*/
152 
153 	.bEndpointAddress =	1 | USB_DIR_IN,
154 	.bmAttributes =	USB_ENDPOINT_XFER_INT,
155 	.wMaxPacketSize =	64,
156 	.bInterval =		1,
157 };
158 
159 static struct usb_descriptor_header *sdp_runtime_descs[] = {
160 	(struct usb_descriptor_header *)&sdp_intf_runtime,
161 	(struct usb_descriptor_header *)&sdp_hid_desc,
162 	(struct usb_descriptor_header *)&in_desc,
163 	NULL,
164 };
165 
166 /* This is synchronized with what the SoC implementation reports */
167 static struct hid_report sdp_hid_report = {
168 	.usage_page = {
169 		0x06, 0x00, 0xff, /* Usage Page */
170 		0x09, 0x01, /* Usage (Pointer?) */
171 		0xa1, 0x01, /* Collection */
172 
173 		0x85, 0x01, /* Report ID */
174 		0x19, 0x01, /* Usage Minimum */
175 		0x29, 0x01, /* Usage Maximum */
176 		0x15, 0x00, /* Local Minimum */
177 		0x26, 0xFF, 0x00, /* Local Maximum? */
178 		0x75, 0x08, /* Report Size */
179 		0x95, 0x10, /* Report Count */
180 		0x91, 0x02, /* Output Data */
181 
182 		0x85, 0x02, /* Report ID */
183 		0x19, 0x01, /* Usage Minimum */
184 		0x29, 0x01, /* Usage Maximum */
185 		0x15, 0x00, /* Local Minimum */
186 		0x26, 0xFF, 0x00, /* Local Maximum? */
187 		0x75, 0x80, /* Report Size 128 */
188 		0x95, 0x40, /* Report Count */
189 		0x91, 0x02, /* Output Data */
190 
191 		0x85, 0x03, /* Report ID */
192 		0x19, 0x01, /* Usage Minimum */
193 		0x29, 0x01, /* Usage Maximum */
194 		0x15, 0x00, /* Local Minimum */
195 		0x26, 0xFF, 0x00, /* Local Maximum? */
196 		0x75, 0x08, /* Report Size 8 */
197 		0x95, 0x04, /* Report Count */
198 		0x81, 0x02, /* Input Data */
199 
200 		0x85, 0x04, /* Report ID */
201 		0x19, 0x01, /* Usage Minimum */
202 		0x29, 0x01, /* Usage Maximum */
203 		0x15, 0x00, /* Local Minimum */
204 		0x26, 0xFF, 0x00, /* Local Maximum? */
205 		0x75, 0x08, /* Report Size 8 */
206 		0x95, 0x40, /* Report Count */
207 		0x81, 0x02, /* Input Data */
208 		0xc0
209 	},
210 };
211 
212 static const char sdp_name[] = "Serial Downloader Protocol";
213 
214 /*
215  * static strings, in UTF-8
216  */
217 static struct usb_string strings_sdp_generic[] = {
218 	[0].s = sdp_name,
219 	{  }			/* end of list */
220 };
221 
222 static struct usb_gadget_strings stringtab_sdp_generic = {
223 	.language	= 0x0409,	/* en-us */
224 	.strings	= strings_sdp_generic,
225 };
226 
227 static struct usb_gadget_strings *sdp_generic_strings[] = {
228 	&stringtab_sdp_generic,
229 	NULL,
230 };
231 
232 static inline void *sdp_ptr(u32 val)
233 {
234 	return (void *)(uintptr_t)val;
235 }
236 
237 static void sdp_rx_command_complete(struct usb_ep *ep, struct usb_request *req)
238 {
239 	struct f_sdp *sdp = req->context;
240 	int status = req->status;
241 	u8 *data = req->buf;
242 	u8 report = data[0];
243 
244 	if (status != 0) {
245 		pr_err("Status: %d\n", status);
246 		return;
247 	}
248 
249 	if (report != 1) {
250 		pr_err("Unexpected report %d\n", report);
251 		return;
252 	}
253 
254 	struct sdp_command *cmd = req->buf + 1;
255 
256 	debug("%s: command: %04x, addr: %08x, cnt: %u\n",
257 	      __func__, be16_to_cpu(cmd->cmd),
258 	      be32_to_cpu(cmd->addr), be32_to_cpu(cmd->cnt));
259 
260 	switch (be16_to_cpu(cmd->cmd)) {
261 	case SDP_READ_REGISTER:
262 		sdp->always_send_status = false;
263 		sdp->error_status = 0x0;
264 
265 		sdp->state = SDP_STATE_TX_SEC_CONF;
266 		sdp->dnl_address = be32_to_cpu(cmd->addr);
267 		sdp->dnl_bytes_remaining = be32_to_cpu(cmd->cnt);
268 		sdp->next_state = SDP_STATE_TX_REGISTER;
269 		printf("Reading %d registers at 0x%08x... ",
270 		       sdp->dnl_bytes_remaining, sdp->dnl_address);
271 		break;
272 	case SDP_WRITE_FILE:
273 		sdp->always_send_status = true;
274 		sdp->error_status = SDP_WRITE_FILE_COMPLETE;
275 
276 		sdp->state = SDP_STATE_RX_FILE_DATA;
277 		sdp->dnl_address = be32_to_cpu(cmd->addr);
278 		sdp->dnl_bytes_remaining = be32_to_cpu(cmd->cnt);
279 		sdp->next_state = SDP_STATE_IDLE;
280 
281 		printf("Downloading file of size %d to 0x%08x... ",
282 		       sdp->dnl_bytes_remaining, sdp->dnl_address);
283 
284 		break;
285 	case SDP_ERROR_STATUS:
286 		sdp->always_send_status = true;
287 		sdp->error_status = 0;
288 
289 		sdp->state = SDP_STATE_TX_SEC_CONF;
290 		sdp->next_state = SDP_STATE_IDLE;
291 		break;
292 	case SDP_DCD_WRITE:
293 		sdp->always_send_status = true;
294 		sdp->error_status = SDP_WRITE_REGISTER_COMPLETE;
295 
296 		sdp->state = SDP_STATE_RX_DCD_DATA;
297 		sdp->dnl_bytes_remaining = be32_to_cpu(cmd->cnt);
298 		sdp->next_state = SDP_STATE_IDLE;
299 		break;
300 	case SDP_JUMP_ADDRESS:
301 		sdp->always_send_status = false;
302 		sdp->error_status = 0;
303 
304 		sdp->jmp_address = be32_to_cpu(cmd->addr);
305 		sdp->state = SDP_STATE_TX_SEC_CONF;
306 		sdp->next_state = SDP_STATE_JUMP;
307 		break;
308 	case SDP_SKIP_DCD_HEADER:
309 		sdp->always_send_status = true;
310 		sdp->error_status = SDP_SKIP_DCD_HEADER_COMPLETE;
311 
312 		/* Ignore command, DCD not supported anyway */
313 		sdp->state = SDP_STATE_TX_SEC_CONF;
314 		sdp->next_state = SDP_STATE_IDLE;
315 		break;
316 	default:
317 		pr_err("Unknown command: %04x\n", be16_to_cpu(cmd->cmd));
318 	}
319 }
320 
321 static void sdp_rx_data_complete(struct usb_ep *ep, struct usb_request *req)
322 {
323 	struct f_sdp *sdp = req->context;
324 	int status = req->status;
325 	u8 *data = req->buf;
326 	u8 report = data[0];
327 	int datalen = req->length - 1;
328 
329 	if (status != 0) {
330 		pr_err("Status: %d\n", status);
331 		return;
332 	}
333 
334 	if (report != 2) {
335 		pr_err("Unexpected report %d\n", report);
336 		return;
337 	}
338 
339 	if (sdp->dnl_bytes_remaining < datalen) {
340 		/*
341 		 * Some USB stacks require to send a complete buffer as
342 		 * specified in the HID descriptor. This leads to longer
343 		 * transfers than the file length, no problem for us.
344 		 */
345 		sdp->dnl_bytes_remaining = 0;
346 	} else {
347 		sdp->dnl_bytes_remaining -= datalen;
348 	}
349 
350 	if (sdp->state == SDP_STATE_RX_FILE_DATA) {
351 		memcpy(sdp_ptr(sdp->dnl_address), req->buf + 1, datalen);
352 		sdp->dnl_address += datalen;
353 	}
354 
355 	if (sdp->dnl_bytes_remaining)
356 		return;
357 
358 	printf("done\n");
359 
360 	switch (sdp->state) {
361 	case SDP_STATE_RX_FILE_DATA:
362 		sdp->state = SDP_STATE_TX_SEC_CONF;
363 		break;
364 	case SDP_STATE_RX_DCD_DATA:
365 		sdp->state = SDP_STATE_TX_SEC_CONF;
366 		break;
367 	default:
368 		pr_err("Invalid state: %d\n", sdp->state);
369 	}
370 }
371 
372 static void sdp_tx_complete(struct usb_ep *ep, struct usb_request *req)
373 {
374 	struct f_sdp *sdp = req->context;
375 	int status = req->status;
376 
377 	if (status != 0) {
378 		pr_err("Status: %d\n", status);
379 		return;
380 	}
381 
382 	switch (sdp->state) {
383 	case SDP_STATE_TX_SEC_CONF_BUSY:
384 		/* Not all commands require status report */
385 		if (sdp->always_send_status || sdp->error_status)
386 			sdp->state = SDP_STATE_TX_STATUS;
387 		else
388 			sdp->state = sdp->next_state;
389 
390 		break;
391 	case SDP_STATE_TX_STATUS_BUSY:
392 		sdp->state = sdp->next_state;
393 		break;
394 	case SDP_STATE_TX_REGISTER_BUSY:
395 		if (sdp->dnl_bytes_remaining)
396 			sdp->state = SDP_STATE_TX_REGISTER;
397 		else
398 			sdp->state = SDP_STATE_IDLE;
399 		break;
400 	default:
401 		pr_err("Wrong State: %d\n", sdp->state);
402 		sdp->state = SDP_STATE_IDLE;
403 		break;
404 	}
405 	debug("%s complete --> %d, %d/%d\n", ep->name,
406 	      status, req->actual, req->length);
407 }
408 
409 static int sdp_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
410 {
411 	struct usb_gadget *gadget = f->config->cdev->gadget;
412 	struct usb_request *req = f->config->cdev->req;
413 	struct f_sdp *sdp = f->config->cdev->req->context;
414 	u16 len = le16_to_cpu(ctrl->wLength);
415 	u16 w_value = le16_to_cpu(ctrl->wValue);
416 	int value = 0;
417 	u8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
418 
419 	debug("w_value: 0x%04x len: 0x%04x\n", w_value, len);
420 	debug("req_type: 0x%02x ctrl->bRequest: 0x%02x sdp->state: %d\n",
421 	      req_type, ctrl->bRequest, sdp->state);
422 
423 	if (req_type == USB_TYPE_STANDARD) {
424 		if (ctrl->bRequest == USB_REQ_GET_DESCRIPTOR) {
425 			/* Send HID report descriptor */
426 			value = min(len, (u16) sizeof(sdp_hid_report));
427 			memcpy(req->buf, &sdp_hid_report, value);
428 			sdp->configuration_done = true;
429 		}
430 	}
431 
432 	if (req_type == USB_TYPE_CLASS) {
433 		int report = w_value & HID_REPORT_ID_MASK;
434 
435 		/* HID (SDP) request */
436 		switch (ctrl->bRequest) {
437 		case HID_REQ_SET_REPORT:
438 			switch (report) {
439 			case 1:
440 				value = SDP_COMMAND_LEN + 1;
441 				req->complete = sdp_rx_command_complete;
442 				break;
443 			case 2:
444 				value = len;
445 				req->complete = sdp_rx_data_complete;
446 				break;
447 			}
448 		}
449 	}
450 
451 	if (value >= 0) {
452 		req->length = value;
453 		req->zero = value < len;
454 		value = usb_ep_queue(gadget->ep0, req, 0);
455 		if (value < 0) {
456 			debug("ep_queue --> %d\n", value);
457 			req->status = 0;
458 		}
459 	}
460 
461 	return value;
462 }
463 
464 static int sdp_bind(struct usb_configuration *c, struct usb_function *f)
465 {
466 	struct usb_gadget *gadget = c->cdev->gadget;
467 	struct usb_composite_dev *cdev = c->cdev;
468 	struct f_sdp *sdp = func_to_sdp(f);
469 	int rv = 0, id;
470 
471 	id = usb_interface_id(c, f);
472 	if (id < 0)
473 		return id;
474 	sdp_intf_runtime.bInterfaceNumber = id;
475 
476 	struct usb_ep *ep;
477 
478 	/* allocate instance-specific endpoints */
479 	ep = usb_ep_autoconfig(gadget, &in_desc);
480 	if (!ep) {
481 		rv = -ENODEV;
482 		goto error;
483 	}
484 
485 	sdp->in_ep = ep; /* Store IN EP for enabling @ setup */
486 
487 	cdev->req->context = sdp;
488 
489 error:
490 	return rv;
491 }
492 
493 static void sdp_unbind(struct usb_configuration *c, struct usb_function *f)
494 {
495 	free(sdp_func);
496 	sdp_func = NULL;
497 }
498 
499 static struct usb_request *alloc_ep_req(struct usb_ep *ep, unsigned length)
500 {
501 	struct usb_request *req;
502 
503 	req = usb_ep_alloc_request(ep, 0);
504 	if (!req)
505 		return req;
506 
507 	req->length = length;
508 	req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, length);
509 	if (!req->buf) {
510 		usb_ep_free_request(ep, req);
511 		req = NULL;
512 	}
513 
514 	return req;
515 }
516 
517 
518 static struct usb_request *sdp_start_ep(struct usb_ep *ep)
519 {
520 	struct usb_request *req;
521 
522 	req = alloc_ep_req(ep, 64);
523 	debug("%s: ep:%p req:%p\n", __func__, ep, req);
524 
525 	if (!req)
526 		return NULL;
527 
528 	memset(req->buf, 0, req->length);
529 	req->complete = sdp_tx_complete;
530 
531 	return req;
532 }
533 static int sdp_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
534 {
535 	struct f_sdp *sdp = func_to_sdp(f);
536 	struct usb_composite_dev *cdev = f->config->cdev;
537 	int result;
538 
539 	debug("%s: intf: %d alt: %d\n", __func__, intf, alt);
540 
541 	result = usb_ep_enable(sdp->in_ep, &in_desc);
542 	if (result)
543 		return result;
544 	sdp->in_req = sdp_start_ep(sdp->in_ep);
545 	sdp->in_req->context = sdp;
546 
547 	sdp->in_ep->driver_data = cdev; /* claim */
548 
549 	sdp->altsetting = alt;
550 	sdp->state = SDP_STATE_IDLE;
551 
552 	return 0;
553 }
554 
555 static int sdp_get_alt(struct usb_function *f, unsigned intf)
556 {
557 	struct f_sdp *sdp = func_to_sdp(f);
558 
559 	return sdp->altsetting;
560 }
561 
562 static void sdp_disable(struct usb_function *f)
563 {
564 	struct f_sdp *sdp = func_to_sdp(f);
565 
566 	usb_ep_disable(sdp->in_ep);
567 
568 	if (sdp->in_req) {
569 		free(sdp->in_req);
570 		sdp->in_req = NULL;
571 	}
572 }
573 
574 static int sdp_bind_config(struct usb_configuration *c)
575 {
576 	int status;
577 
578 	if (!sdp_func) {
579 		sdp_func = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*sdp_func));
580 		if (!sdp_func)
581 			return -ENOMEM;
582 	}
583 
584 	memset(sdp_func, 0, sizeof(*sdp_func));
585 
586 	sdp_func->usb_function.name = "sdp";
587 	sdp_func->usb_function.hs_descriptors = sdp_runtime_descs;
588 	sdp_func->usb_function.descriptors = sdp_runtime_descs;
589 	sdp_func->usb_function.bind = sdp_bind;
590 	sdp_func->usb_function.unbind = sdp_unbind;
591 	sdp_func->usb_function.set_alt = sdp_set_alt;
592 	sdp_func->usb_function.get_alt = sdp_get_alt;
593 	sdp_func->usb_function.disable = sdp_disable;
594 	sdp_func->usb_function.strings = sdp_generic_strings;
595 	sdp_func->usb_function.setup = sdp_setup;
596 
597 	status = usb_add_function(c, &sdp_func->usb_function);
598 
599 	return status;
600 }
601 
602 int sdp_init(int controller_index)
603 {
604 	printf("SDP: initialize...\n");
605 	while (!sdp_func->configuration_done) {
606 		if (ctrlc()) {
607 			puts("\rCTRL+C - Operation aborted.\n");
608 			return 1;
609 		}
610 
611 		WATCHDOG_RESET();
612 		usb_gadget_handle_interrupts(controller_index);
613 	}
614 
615 	return 0;
616 }
617 
618 static u32 sdp_jump_imxheader(void *address)
619 {
620 	flash_header_v2_t *headerv2 = address;
621 	ulong (*entry)(void);
622 
623 	if (headerv2->header.tag != IVT_HEADER_TAG) {
624 		printf("Header Tag is not an IMX image\n");
625 		return SDP_ERROR_IMXHEADER;
626 	}
627 
628 	printf("Jumping to 0x%08x\n", headerv2->entry);
629 	entry = sdp_ptr(headerv2->entry);
630 	entry();
631 
632 	/* The image probably never returns hence we won't reach that point */
633 	return 0;
634 }
635 
636 static void sdp_handle_in_ep(void)
637 {
638 	u8 *data = sdp_func->in_req->buf;
639 	u32 status;
640 	int datalen;
641 
642 	switch (sdp_func->state) {
643 	case SDP_STATE_TX_SEC_CONF:
644 		debug("Report 3: HAB security\n");
645 		data[0] = 3;
646 
647 		status = SDP_SECURITY_OPEN;
648 		memcpy(&data[1], &status, 4);
649 		sdp_func->in_req->length = 5;
650 		usb_ep_queue(sdp_func->in_ep, sdp_func->in_req, 0);
651 		sdp_func->state = SDP_STATE_TX_SEC_CONF_BUSY;
652 		break;
653 
654 	case SDP_STATE_TX_STATUS:
655 		debug("Report 4: Status\n");
656 		data[0] = 4;
657 
658 		memcpy(&data[1], &sdp_func->error_status, 4);
659 		sdp_func->in_req->length = 65;
660 		usb_ep_queue(sdp_func->in_ep, sdp_func->in_req, 0);
661 		sdp_func->state = SDP_STATE_TX_STATUS_BUSY;
662 		break;
663 	case SDP_STATE_TX_REGISTER:
664 		debug("Report 4: Register Values\n");
665 		data[0] = 4;
666 
667 		datalen = sdp_func->dnl_bytes_remaining;
668 
669 		if (datalen > 64)
670 			datalen = 64;
671 
672 		memcpy(&data[1], sdp_ptr(sdp_func->dnl_address), datalen);
673 		sdp_func->in_req->length = 65;
674 
675 		sdp_func->dnl_bytes_remaining -= datalen;
676 		sdp_func->dnl_address += datalen;
677 
678 		usb_ep_queue(sdp_func->in_ep, sdp_func->in_req, 0);
679 		sdp_func->state = SDP_STATE_TX_REGISTER_BUSY;
680 		break;
681 	case SDP_STATE_JUMP:
682 		printf("Jumping to header at 0x%08x\n", sdp_func->jmp_address);
683 		status = sdp_jump_imxheader(sdp_ptr(sdp_func->jmp_address));
684 
685 		/* If imx header fails, try some U-Boot specific headers */
686 		if (status) {
687 #ifdef CONFIG_SPL_BUILD
688 			/* In SPL, allow jumps to U-Boot images */
689 			struct spl_image_info spl_image = {};
690 			spl_parse_image_header(&spl_image,
691 				(struct image_header *)sdp_func->jmp_address);
692 			jump_to_image_no_args(&spl_image);
693 #else
694 			/* In U-Boot, allow jumps to scripts */
695 			source(sdp_func->jmp_address, "script@1");
696 #endif
697 		}
698 
699 		sdp_func->next_state = SDP_STATE_IDLE;
700 		sdp_func->error_status = status;
701 
702 		/* Only send Report 4 if there was an error */
703 		if (status)
704 			sdp_func->state = SDP_STATE_TX_STATUS;
705 		else
706 			sdp_func->state = SDP_STATE_IDLE;
707 		break;
708 	default:
709 		break;
710 	};
711 }
712 
713 void sdp_handle(int controller_index)
714 {
715 	printf("SDP: handle requests...\n");
716 	while (1) {
717 		if (ctrlc()) {
718 			puts("\rCTRL+C - Operation aborted.\n");
719 			return;
720 		}
721 
722 		WATCHDOG_RESET();
723 		usb_gadget_handle_interrupts(controller_index);
724 
725 		sdp_handle_in_ep();
726 	}
727 }
728 
729 int sdp_add(struct usb_configuration *c)
730 {
731 	int id;
732 
733 	id = usb_string_id(c->cdev);
734 	if (id < 0)
735 		return id;
736 	strings_sdp_generic[0].id = id;
737 	sdp_intf_runtime.iInterface = id;
738 
739 	debug("%s: cdev: %p gadget: %p gadget->ep0: %p\n", __func__,
740 	      c->cdev, c->cdev->gadget, c->cdev->gadget->ep0);
741 
742 	return sdp_bind_config(c);
743 }
744 
745 DECLARE_GADGET_BIND_CALLBACK(usb_dnl_sdp, sdp_add);
746