xref: /rk3399_rockchip-uboot/common/usb.c (revision 23faf2bc9e80e3ee2c06a3a61bb8a02e43a97097)
1 /*
2  *
3  * Most of this source has been derived from the Linux USB
4  * project:
5  * (C) Copyright Linus Torvalds 1999
6  * (C) Copyright Johannes Erdfelt 1999-2001
7  * (C) Copyright Andreas Gal 1999
8  * (C) Copyright Gregory P. Smith 1999
9  * (C) Copyright Deti Fliegl 1999 (new USB architecture)
10  * (C) Copyright Randy Dunlap 2000
11  * (C) Copyright David Brownell 2000 (kernel hotplug, usb_device_id)
12  * (C) Copyright Yggdrasil Computing, Inc. 2000
13  *     (usb_device_id matching changes by Adam J. Richter)
14  *
15  * Adapted for U-Boot:
16  * (C) Copyright 2001 Denis Peter, MPL AG Switzerland
17  *
18  * See file CREDITS for list of people who contributed to this
19  * project.
20  *
21  * This program is free software; you can redistribute it and/or
22  * modify it under the terms of the GNU General Public License as
23  * published by the Free Software Foundation; either version 2 of
24  * the License, or (at your option) any later version.
25  *
26  * This program is distributed in the hope that it will be useful,
27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
29  * GNU General Public License for more details.
30  *
31  * You should have received a copy of the GNU General Public License
32  * along with this program; if not, write to the Free Software
33  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
34  * MA 02111-1307 USA
35  *
36  */
37 
38 /*
39  * How it works:
40  *
41  * Since this is a bootloader, the devices will not be automatic
42  * (re)configured on hotplug, but after a restart of the USB the
43  * device should work.
44  *
45  * For each transfer (except "Interrupt") we wait for completion.
46  */
47 #include <common.h>
48 #include <command.h>
49 #include <asm/processor.h>
50 #include <linux/ctype.h>
51 #include <asm/byteorder.h>
52 #include <asm/unaligned.h>
53 
54 #include <usb.h>
55 #ifdef CONFIG_4xx
56 #include <asm/4xx_pci.h>
57 #endif
58 
59 #ifdef DEBUG
60 #define USB_DEBUG	1
61 #define USB_HUB_DEBUG	1
62 #else
63 #define USB_DEBUG	0
64 #define USB_HUB_DEBUG	0
65 #endif
66 
67 #define USB_PRINTF(fmt, args...)	debug_cond(USB_DEBUG, fmt, ##args)
68 #define USB_HUB_PRINTF(fmt, args...)	debug_cond(USB_HUB_DEBUG, fmt, ##args)
69 
70 #define USB_BUFSIZ	512
71 
72 static struct usb_device usb_dev[USB_MAX_DEVICE];
73 static int dev_index;
74 static int running;
75 static int asynch_allowed;
76 static struct devrequest setup_packet;
77 
78 char usb_started; /* flag for the started/stopped USB status */
79 
80 /**********************************************************************
81  * some forward declerations...
82  */
83 static void usb_scan_devices(void);
84 
85 /***********************************************************************
86  * wait_ms
87  */
88 
89 inline void wait_ms(unsigned long ms)
90 {
91 	while (ms-- > 0)
92 		udelay(1000);
93 }
94 
95 /***************************************************************************
96  * Init USB Device
97  */
98 
99 int usb_init(void)
100 {
101 	int result;
102 
103 	running = 0;
104 	dev_index = 0;
105 	asynch_allowed = 1;
106 	usb_hub_reset();
107 	/* init low_level USB */
108 	printf("USB:   ");
109 	result = usb_lowlevel_init();
110 	/* if lowlevel init is OK, scan the bus for devices
111 	 * i.e. search HUBs and configure them */
112 	if (result == 0) {
113 		printf("scanning bus for devices... ");
114 		running = 1;
115 		usb_scan_devices();
116 		usb_started = 1;
117 		return 0;
118 	} else {
119 		printf("Error, couldn't init Lowlevel part\n");
120 		usb_started = 0;
121 		return -1;
122 	}
123 }
124 
125 /******************************************************************************
126  * Stop USB this stops the LowLevel Part and deregisters USB devices.
127  */
128 int usb_stop(void)
129 {
130 	int res = 0;
131 
132 	if (usb_started) {
133 		asynch_allowed = 1;
134 		usb_started = 0;
135 		usb_hub_reset();
136 		res = usb_lowlevel_stop();
137 	}
138 	return res;
139 }
140 
141 /*
142  * disables the asynch behaviour of the control message. This is used for data
143  * transfers that uses the exclusiv access to the control and bulk messages.
144  * Returns the old value so it can be restored later.
145  */
146 int usb_disable_asynch(int disable)
147 {
148 	int old_value = asynch_allowed;
149 
150 	asynch_allowed = !disable;
151 	return old_value;
152 }
153 
154 
155 /*-------------------------------------------------------------------
156  * Message wrappers.
157  *
158  */
159 
160 /*
161  * submits an Interrupt Message
162  */
163 int usb_submit_int_msg(struct usb_device *dev, unsigned long pipe,
164 			void *buffer, int transfer_len, int interval)
165 {
166 	return submit_int_msg(dev, pipe, buffer, transfer_len, interval);
167 }
168 
169 /*
170  * submits a control message and waits for comletion (at least timeout * 1ms)
171  * If timeout is 0, we don't wait for completion (used as example to set and
172  * clear keyboards LEDs). For data transfers, (storage transfers) we don't
173  * allow control messages with 0 timeout, by previousely resetting the flag
174  * asynch_allowed (usb_disable_asynch(1)).
175  * returns the transfered length if OK or -1 if error. The transfered length
176  * and the current status are stored in the dev->act_len and dev->status.
177  */
178 int usb_control_msg(struct usb_device *dev, unsigned int pipe,
179 			unsigned char request, unsigned char requesttype,
180 			unsigned short value, unsigned short index,
181 			void *data, unsigned short size, int timeout)
182 {
183 	if ((timeout == 0) && (!asynch_allowed)) {
184 		/* request for a asynch control pipe is not allowed */
185 		return -1;
186 	}
187 
188 	/* set setup command */
189 	setup_packet.requesttype = requesttype;
190 	setup_packet.request = request;
191 	setup_packet.value = cpu_to_le16(value);
192 	setup_packet.index = cpu_to_le16(index);
193 	setup_packet.length = cpu_to_le16(size);
194 	USB_PRINTF("usb_control_msg: request: 0x%X, requesttype: 0x%X, " \
195 		   "value 0x%X index 0x%X length 0x%X\n",
196 		   request, requesttype, value, index, size);
197 	dev->status = USB_ST_NOT_PROC; /*not yet processed */
198 
199 	submit_control_msg(dev, pipe, data, size, &setup_packet);
200 	if (timeout == 0)
201 		return (int)size;
202 
203 	/*
204 	 * Wait for status to update until timeout expires, USB driver
205 	 * interrupt handler may set the status when the USB operation has
206 	 * been completed.
207 	 */
208 	while (timeout--) {
209 		if (!((volatile unsigned long)dev->status & USB_ST_NOT_PROC))
210 			break;
211 		wait_ms(1);
212 	}
213 	if (dev->status)
214 		return -1;
215 
216 	return dev->act_len;
217 
218 }
219 
220 /*-------------------------------------------------------------------
221  * submits bulk message, and waits for completion. returns 0 if Ok or
222  * -1 if Error.
223  * synchronous behavior
224  */
225 int usb_bulk_msg(struct usb_device *dev, unsigned int pipe,
226 			void *data, int len, int *actual_length, int timeout)
227 {
228 	if (len < 0)
229 		return -1;
230 	dev->status = USB_ST_NOT_PROC; /*not yet processed */
231 	submit_bulk_msg(dev, pipe, data, len);
232 	while (timeout--) {
233 		if (!((volatile unsigned long)dev->status & USB_ST_NOT_PROC))
234 			break;
235 		wait_ms(1);
236 	}
237 	*actual_length = dev->act_len;
238 	if (dev->status == 0)
239 		return 0;
240 	else
241 		return -1;
242 }
243 
244 
245 /*-------------------------------------------------------------------
246  * Max Packet stuff
247  */
248 
249 /*
250  * returns the max packet size, depending on the pipe direction and
251  * the configurations values
252  */
253 int usb_maxpacket(struct usb_device *dev, unsigned long pipe)
254 {
255 	/* direction is out -> use emaxpacket out */
256 	if ((pipe & USB_DIR_IN) == 0)
257 		return dev->epmaxpacketout[((pipe>>15) & 0xf)];
258 	else
259 		return dev->epmaxpacketin[((pipe>>15) & 0xf)];
260 }
261 
262 /*
263  * The routine usb_set_maxpacket_ep() is extracted from the loop of routine
264  * usb_set_maxpacket(), because the optimizer of GCC 4.x chokes on this routine
265  * when it is inlined in 1 single routine. What happens is that the register r3
266  * is used as loop-count 'i', but gets overwritten later on.
267  * This is clearly a compiler bug, but it is easier to workaround it here than
268  * to update the compiler (Occurs with at least several GCC 4.{1,2},x
269  * CodeSourcery compilers like e.g. 2007q3, 2008q1, 2008q3 lite editions on ARM)
270  *
271  * NOTE: Similar behaviour was observed with GCC4.6 on ARMv5.
272  */
273 static void  __attribute__((noinline))
274 usb_set_maxpacket_ep(struct usb_device *dev, int if_idx, int ep_idx)
275 {
276 	int b;
277 	struct usb_endpoint_descriptor *ep;
278 	u16 ep_wMaxPacketSize;
279 
280 	ep = &dev->config.if_desc[if_idx].ep_desc[ep_idx];
281 
282 	b = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
283 	ep_wMaxPacketSize = get_unaligned(&ep->wMaxPacketSize);
284 
285 	if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
286 						USB_ENDPOINT_XFER_CONTROL) {
287 		/* Control => bidirectional */
288 		dev->epmaxpacketout[b] = ep_wMaxPacketSize;
289 		dev->epmaxpacketin[b] = ep_wMaxPacketSize;
290 		USB_PRINTF("##Control EP epmaxpacketout/in[%d] = %d\n",
291 			   b, dev->epmaxpacketin[b]);
292 	} else {
293 		if ((ep->bEndpointAddress & 0x80) == 0) {
294 			/* OUT Endpoint */
295 			if (ep_wMaxPacketSize > dev->epmaxpacketout[b]) {
296 				dev->epmaxpacketout[b] = ep_wMaxPacketSize;
297 				USB_PRINTF("##EP epmaxpacketout[%d] = %d\n",
298 					   b, dev->epmaxpacketout[b]);
299 			}
300 		} else {
301 			/* IN Endpoint */
302 			if (ep_wMaxPacketSize > dev->epmaxpacketin[b]) {
303 				dev->epmaxpacketin[b] = ep_wMaxPacketSize;
304 				USB_PRINTF("##EP epmaxpacketin[%d] = %d\n",
305 					   b, dev->epmaxpacketin[b]);
306 			}
307 		} /* if out */
308 	} /* if control */
309 }
310 
311 /*
312  * set the max packed value of all endpoints in the given configuration
313  */
314 static int usb_set_maxpacket(struct usb_device *dev)
315 {
316 	int i, ii;
317 
318 	for (i = 0; i < dev->config.desc.bNumInterfaces; i++)
319 		for (ii = 0; ii < dev->config.if_desc[i].desc.bNumEndpoints; ii++)
320 			usb_set_maxpacket_ep(dev, i, ii);
321 
322 	return 0;
323 }
324 
325 /*******************************************************************************
326  * Parse the config, located in buffer, and fills the dev->config structure.
327  * Note that all little/big endian swapping are done automatically.
328  */
329 static int usb_parse_config(struct usb_device *dev,
330 			unsigned char *buffer, int cfgno)
331 {
332 	struct usb_descriptor_header *head;
333 	int index, ifno, epno, curr_if_num;
334 	int i;
335 	u16 ep_wMaxPacketSize;
336 
337 	ifno = -1;
338 	epno = -1;
339 	curr_if_num = -1;
340 
341 	dev->configno = cfgno;
342 	head = (struct usb_descriptor_header *) &buffer[0];
343 	if (head->bDescriptorType != USB_DT_CONFIG) {
344 		printf(" ERROR: NOT USB_CONFIG_DESC %x\n",
345 			head->bDescriptorType);
346 		return -1;
347 	}
348 	memcpy(&dev->config, buffer, buffer[0]);
349 	le16_to_cpus(&(dev->config.desc.wTotalLength));
350 	dev->config.no_of_if = 0;
351 
352 	index = dev->config.desc.bLength;
353 	/* Ok the first entry must be a configuration entry,
354 	 * now process the others */
355 	head = (struct usb_descriptor_header *) &buffer[index];
356 	while (index + 1 < dev->config.desc.wTotalLength) {
357 		switch (head->bDescriptorType) {
358 		case USB_DT_INTERFACE:
359 			if (((struct usb_interface_descriptor *) \
360 			     &buffer[index])->bInterfaceNumber != curr_if_num) {
361 				/* this is a new interface, copy new desc */
362 				ifno = dev->config.no_of_if;
363 				dev->config.no_of_if++;
364 				memcpy(&dev->config.if_desc[ifno],
365 					&buffer[index], buffer[index]);
366 				dev->config.if_desc[ifno].no_of_ep = 0;
367 				dev->config.if_desc[ifno].num_altsetting = 1;
368 				curr_if_num =
369 				     dev->config.if_desc[ifno].desc.bInterfaceNumber;
370 			} else {
371 				/* found alternate setting for the interface */
372 				dev->config.if_desc[ifno].num_altsetting++;
373 			}
374 			break;
375 		case USB_DT_ENDPOINT:
376 			epno = dev->config.if_desc[ifno].no_of_ep;
377 			/* found an endpoint */
378 			dev->config.if_desc[ifno].no_of_ep++;
379 			memcpy(&dev->config.if_desc[ifno].ep_desc[epno],
380 				&buffer[index], buffer[index]);
381 			ep_wMaxPacketSize = get_unaligned(&dev->config.\
382 							if_desc[ifno].\
383 							ep_desc[epno].\
384 							wMaxPacketSize);
385 			put_unaligned(le16_to_cpu(ep_wMaxPacketSize),
386 					&dev->config.\
387 					if_desc[ifno].\
388 					ep_desc[epno].\
389 					wMaxPacketSize);
390 			USB_PRINTF("if %d, ep %d\n", ifno, epno);
391 			break;
392 		default:
393 			if (head->bLength == 0)
394 				return 1;
395 
396 			USB_PRINTF("unknown Description Type : %x\n",
397 				   head->bDescriptorType);
398 
399 			{
400 #ifdef USB_DEBUG
401 				unsigned char *ch = (unsigned char *)head;
402 #endif
403 				for (i = 0; i < head->bLength; i++)
404 					USB_PRINTF("%02X ", *ch++);
405 				USB_PRINTF("\n\n\n");
406 			}
407 			break;
408 		}
409 		index += head->bLength;
410 		head = (struct usb_descriptor_header *)&buffer[index];
411 	}
412 	return 1;
413 }
414 
415 /***********************************************************************
416  * Clears an endpoint
417  * endp: endpoint number in bits 0-3;
418  * direction flag in bit 7 (1 = IN, 0 = OUT)
419  */
420 int usb_clear_halt(struct usb_device *dev, int pipe)
421 {
422 	int result;
423 	int endp = usb_pipeendpoint(pipe)|(usb_pipein(pipe)<<7);
424 
425 	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
426 				 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 0,
427 				 endp, NULL, 0, USB_CNTL_TIMEOUT * 3);
428 
429 	/* don't clear if failed */
430 	if (result < 0)
431 		return result;
432 
433 	/*
434 	 * NOTE: we do not get status and verify reset was successful
435 	 * as some devices are reported to lock up upon this check..
436 	 */
437 
438 	usb_endpoint_running(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe));
439 
440 	/* toggle is reset on clear */
441 	usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0);
442 	return 0;
443 }
444 
445 
446 /**********************************************************************
447  * get_descriptor type
448  */
449 static int usb_get_descriptor(struct usb_device *dev, unsigned char type,
450 			unsigned char index, void *buf, int size)
451 {
452 	int res;
453 	res = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
454 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
455 			(type << 8) + index, 0,
456 			buf, size, USB_CNTL_TIMEOUT);
457 	return res;
458 }
459 
460 /**********************************************************************
461  * gets configuration cfgno and store it in the buffer
462  */
463 int usb_get_configuration_no(struct usb_device *dev,
464 			     unsigned char *buffer, int cfgno)
465 {
466 	int result;
467 	unsigned int tmp;
468 	struct usb_configuration_descriptor *config;
469 
470 	config = (struct usb_configuration_descriptor *)&buffer[0];
471 	result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 9);
472 	if (result < 9) {
473 		if (result < 0)
474 			printf("unable to get descriptor, error %lX\n",
475 				dev->status);
476 		else
477 			printf("config descriptor too short " \
478 				"(expected %i, got %i)\n", 9, result);
479 		return -1;
480 	}
481 	tmp = le16_to_cpu(config->wTotalLength);
482 
483 	if (tmp > USB_BUFSIZ) {
484 		USB_PRINTF("usb_get_configuration_no: failed to get " \
485 			   "descriptor - too long: %d\n", tmp);
486 		return -1;
487 	}
488 
489 	result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, tmp);
490 	USB_PRINTF("get_conf_no %d Result %d, wLength %d\n",
491 		   cfgno, result, tmp);
492 	return result;
493 }
494 
495 /********************************************************************
496  * set address of a device to the value in dev->devnum.
497  * This can only be done by addressing the device via the default address (0)
498  */
499 static int usb_set_address(struct usb_device *dev)
500 {
501 	int res;
502 
503 	USB_PRINTF("set address %d\n", dev->devnum);
504 	res = usb_control_msg(dev, usb_snddefctrl(dev),
505 				USB_REQ_SET_ADDRESS, 0,
506 				(dev->devnum), 0,
507 				NULL, 0, USB_CNTL_TIMEOUT);
508 	return res;
509 }
510 
511 /********************************************************************
512  * set interface number to interface
513  */
514 int usb_set_interface(struct usb_device *dev, int interface, int alternate)
515 {
516 	struct usb_interface *if_face = NULL;
517 	int ret, i;
518 
519 	for (i = 0; i < dev->config.desc.bNumInterfaces; i++) {
520 		if (dev->config.if_desc[i].desc.bInterfaceNumber == interface) {
521 			if_face = &dev->config.if_desc[i];
522 			break;
523 		}
524 	}
525 	if (!if_face) {
526 		printf("selecting invalid interface %d", interface);
527 		return -1;
528 	}
529 	/*
530 	 * We should return now for devices with only one alternate setting.
531 	 * According to 9.4.10 of the Universal Serial Bus Specification
532 	 * Revision 2.0 such devices can return with a STALL. This results in
533 	 * some USB sticks timeouting during initialization and then being
534 	 * unusable in U-Boot.
535 	 */
536 	if (if_face->num_altsetting == 1)
537 		return 0;
538 
539 	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
540 				USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
541 				alternate, interface, NULL, 0,
542 				USB_CNTL_TIMEOUT * 5);
543 	if (ret < 0)
544 		return ret;
545 
546 	return 0;
547 }
548 
549 /********************************************************************
550  * set configuration number to configuration
551  */
552 static int usb_set_configuration(struct usb_device *dev, int configuration)
553 {
554 	int res;
555 	USB_PRINTF("set configuration %d\n", configuration);
556 	/* set setup command */
557 	res = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
558 				USB_REQ_SET_CONFIGURATION, 0,
559 				configuration, 0,
560 				NULL, 0, USB_CNTL_TIMEOUT);
561 	if (res == 0) {
562 		dev->toggle[0] = 0;
563 		dev->toggle[1] = 0;
564 		return 0;
565 	} else
566 		return -1;
567 }
568 
569 /********************************************************************
570  * set protocol to protocol
571  */
572 int usb_set_protocol(struct usb_device *dev, int ifnum, int protocol)
573 {
574 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
575 		USB_REQ_SET_PROTOCOL, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
576 		protocol, ifnum, NULL, 0, USB_CNTL_TIMEOUT);
577 }
578 
579 /********************************************************************
580  * set idle
581  */
582 int usb_set_idle(struct usb_device *dev, int ifnum, int duration, int report_id)
583 {
584 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
585 		USB_REQ_SET_IDLE, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
586 		(duration << 8) | report_id, ifnum, NULL, 0, USB_CNTL_TIMEOUT);
587 }
588 
589 /********************************************************************
590  * get report
591  */
592 int usb_get_report(struct usb_device *dev, int ifnum, unsigned char type,
593 		   unsigned char id, void *buf, int size)
594 {
595 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
596 			USB_REQ_GET_REPORT,
597 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
598 			(type << 8) + id, ifnum, buf, size, USB_CNTL_TIMEOUT);
599 }
600 
601 /********************************************************************
602  * get class descriptor
603  */
604 int usb_get_class_descriptor(struct usb_device *dev, int ifnum,
605 		unsigned char type, unsigned char id, void *buf, int size)
606 {
607 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
608 		USB_REQ_GET_DESCRIPTOR, USB_RECIP_INTERFACE | USB_DIR_IN,
609 		(type << 8) + id, ifnum, buf, size, USB_CNTL_TIMEOUT);
610 }
611 
612 /********************************************************************
613  * get string index in buffer
614  */
615 static int usb_get_string(struct usb_device *dev, unsigned short langid,
616 		   unsigned char index, void *buf, int size)
617 {
618 	int i;
619 	int result;
620 
621 	for (i = 0; i < 3; ++i) {
622 		/* some devices are flaky */
623 		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
624 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
625 			(USB_DT_STRING << 8) + index, langid, buf, size,
626 			USB_CNTL_TIMEOUT);
627 
628 		if (result > 0)
629 			break;
630 	}
631 
632 	return result;
633 }
634 
635 
636 static void usb_try_string_workarounds(unsigned char *buf, int *length)
637 {
638 	int newlength, oldlength = *length;
639 
640 	for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
641 		if (!isprint(buf[newlength]) || buf[newlength + 1])
642 			break;
643 
644 	if (newlength > 2) {
645 		buf[0] = newlength;
646 		*length = newlength;
647 	}
648 }
649 
650 
651 static int usb_string_sub(struct usb_device *dev, unsigned int langid,
652 		unsigned int index, unsigned char *buf)
653 {
654 	int rc;
655 
656 	/* Try to read the string descriptor by asking for the maximum
657 	 * possible number of bytes */
658 	rc = usb_get_string(dev, langid, index, buf, 255);
659 
660 	/* If that failed try to read the descriptor length, then
661 	 * ask for just that many bytes */
662 	if (rc < 2) {
663 		rc = usb_get_string(dev, langid, index, buf, 2);
664 		if (rc == 2)
665 			rc = usb_get_string(dev, langid, index, buf, buf[0]);
666 	}
667 
668 	if (rc >= 2) {
669 		if (!buf[0] && !buf[1])
670 			usb_try_string_workarounds(buf, &rc);
671 
672 		/* There might be extra junk at the end of the descriptor */
673 		if (buf[0] < rc)
674 			rc = buf[0];
675 
676 		rc = rc - (rc & 1); /* force a multiple of two */
677 	}
678 
679 	if (rc < 2)
680 		rc = -1;
681 
682 	return rc;
683 }
684 
685 
686 /********************************************************************
687  * usb_string:
688  * Get string index and translate it to ascii.
689  * returns string length (> 0) or error (< 0)
690  */
691 int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
692 {
693 	unsigned char mybuf[USB_BUFSIZ];
694 	unsigned char *tbuf;
695 	int err;
696 	unsigned int u, idx;
697 
698 	if (size <= 0 || !buf || !index)
699 		return -1;
700 	buf[0] = 0;
701 	tbuf = &mybuf[0];
702 
703 	/* get langid for strings if it's not yet known */
704 	if (!dev->have_langid) {
705 		err = usb_string_sub(dev, 0, 0, tbuf);
706 		if (err < 0) {
707 			USB_PRINTF("error getting string descriptor 0 " \
708 				   "(error=%lx)\n", dev->status);
709 			return -1;
710 		} else if (tbuf[0] < 4) {
711 			USB_PRINTF("string descriptor 0 too short\n");
712 			return -1;
713 		} else {
714 			dev->have_langid = -1;
715 			dev->string_langid = tbuf[2] | (tbuf[3] << 8);
716 				/* always use the first langid listed */
717 			USB_PRINTF("USB device number %d default " \
718 				   "language ID 0x%x\n",
719 				   dev->devnum, dev->string_langid);
720 		}
721 	}
722 
723 	err = usb_string_sub(dev, dev->string_langid, index, tbuf);
724 	if (err < 0)
725 		return err;
726 
727 	size--;		/* leave room for trailing NULL char in output buffer */
728 	for (idx = 0, u = 2; u < err; u += 2) {
729 		if (idx >= size)
730 			break;
731 		if (tbuf[u+1])			/* high byte */
732 			buf[idx++] = '?';  /* non-ASCII character */
733 		else
734 			buf[idx++] = tbuf[u];
735 	}
736 	buf[idx] = 0;
737 	err = idx;
738 	return err;
739 }
740 
741 
742 /********************************************************************
743  * USB device handling:
744  * the USB device are static allocated [USB_MAX_DEVICE].
745  */
746 
747 
748 /* returns a pointer to the device with the index [index].
749  * if the device is not assigned (dev->devnum==-1) returns NULL
750  */
751 struct usb_device *usb_get_dev_index(int index)
752 {
753 	if (usb_dev[index].devnum == -1)
754 		return NULL;
755 	else
756 		return &usb_dev[index];
757 }
758 
759 
760 /* returns a pointer of a new device structure or NULL, if
761  * no device struct is available
762  */
763 struct usb_device *usb_alloc_new_device(void)
764 {
765 	int i;
766 	USB_PRINTF("New Device %d\n", dev_index);
767 	if (dev_index == USB_MAX_DEVICE) {
768 		printf("ERROR, too many USB Devices, max=%d\n", USB_MAX_DEVICE);
769 		return NULL;
770 	}
771 	/* default Address is 0, real addresses start with 1 */
772 	usb_dev[dev_index].devnum = dev_index + 1;
773 	usb_dev[dev_index].maxchild = 0;
774 	for (i = 0; i < USB_MAXCHILDREN; i++)
775 		usb_dev[dev_index].children[i] = NULL;
776 	usb_dev[dev_index].parent = NULL;
777 	dev_index++;
778 	return &usb_dev[dev_index - 1];
779 }
780 
781 
782 /*
783  * By the time we get here, the device has gotten a new device ID
784  * and is in the default state. We need to identify the thing and
785  * get the ball rolling..
786  *
787  * Returns 0 for success, != 0 for error.
788  */
789 int usb_new_device(struct usb_device *dev)
790 {
791 	int addr, err;
792 	int tmp;
793 	unsigned char tmpbuf[USB_BUFSIZ];
794 
795 	/* We still haven't set the Address yet */
796 	addr = dev->devnum;
797 	dev->devnum = 0;
798 
799 #ifdef CONFIG_LEGACY_USB_INIT_SEQ
800 	/* this is the old and known way of initializing devices, it is
801 	 * different than what Windows and Linux are doing. Windows and Linux
802 	 * both retrieve 64 bytes while reading the device descriptor
803 	 * Several USB stick devices report ERR: CTL_TIMEOUT, caused by an
804 	 * invalid header while reading 8 bytes as device descriptor. */
805 	dev->descriptor.bMaxPacketSize0 = 8;	    /* Start off at 8 bytes  */
806 	dev->maxpacketsize = PACKET_SIZE_8;
807 	dev->epmaxpacketin[0] = 8;
808 	dev->epmaxpacketout[0] = 8;
809 
810 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
811 	if (err < 8) {
812 		printf("\n      USB device not responding, " \
813 		       "giving up (status=%lX)\n", dev->status);
814 		return 1;
815 	}
816 #else
817 	/* This is a Windows scheme of initialization sequence, with double
818 	 * reset of the device (Linux uses the same sequence)
819 	 * Some equipment is said to work only with such init sequence; this
820 	 * patch is based on the work by Alan Stern:
821 	 * http://sourceforge.net/mailarchive/forum.php?
822 	 * thread_id=5729457&forum_id=5398
823 	 */
824 	struct usb_device_descriptor *desc;
825 	int port = -1;
826 	struct usb_device *parent = dev->parent;
827 	unsigned short portstatus;
828 
829 	/* send 64-byte GET-DEVICE-DESCRIPTOR request.  Since the descriptor is
830 	 * only 18 bytes long, this will terminate with a short packet.  But if
831 	 * the maxpacket size is 8 or 16 the device may be waiting to transmit
832 	 * some more, or keeps on retransmitting the 8 byte header. */
833 
834 	desc = (struct usb_device_descriptor *)tmpbuf;
835 	dev->descriptor.bMaxPacketSize0 = 64;	    /* Start off at 64 bytes  */
836 	/* Default to 64 byte max packet size */
837 	dev->maxpacketsize = PACKET_SIZE_64;
838 	dev->epmaxpacketin[0] = 64;
839 	dev->epmaxpacketout[0] = 64;
840 
841 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
842 	if (err < 0) {
843 		USB_PRINTF("usb_new_device: usb_get_descriptor() failed\n");
844 		return 1;
845 	}
846 
847 	dev->descriptor.bMaxPacketSize0 = desc->bMaxPacketSize0;
848 
849 	/* find the port number we're at */
850 	if (parent) {
851 		int j;
852 
853 		for (j = 0; j < parent->maxchild; j++) {
854 			if (parent->children[j] == dev) {
855 				port = j;
856 				break;
857 			}
858 		}
859 		if (port < 0) {
860 			printf("usb_new_device:cannot locate device's port.\n");
861 			return 1;
862 		}
863 
864 		/* reset the port for the second time */
865 		err = hub_port_reset(dev->parent, port, &portstatus);
866 		if (err < 0) {
867 			printf("\n     Couldn't reset port %i\n", port);
868 			return 1;
869 		}
870 	}
871 #endif
872 
873 	dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
874 	dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
875 	switch (dev->descriptor.bMaxPacketSize0) {
876 	case 8:
877 		dev->maxpacketsize  = PACKET_SIZE_8;
878 		break;
879 	case 16:
880 		dev->maxpacketsize = PACKET_SIZE_16;
881 		break;
882 	case 32:
883 		dev->maxpacketsize = PACKET_SIZE_32;
884 		break;
885 	case 64:
886 		dev->maxpacketsize = PACKET_SIZE_64;
887 		break;
888 	}
889 	dev->devnum = addr;
890 
891 	err = usb_set_address(dev); /* set address */
892 
893 	if (err < 0) {
894 		printf("\n      USB device not accepting new address " \
895 			"(error=%lX)\n", dev->status);
896 		return 1;
897 	}
898 
899 	wait_ms(10);	/* Let the SET_ADDRESS settle */
900 
901 	tmp = sizeof(dev->descriptor);
902 
903 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
904 				 &dev->descriptor, sizeof(dev->descriptor));
905 	if (err < tmp) {
906 		if (err < 0)
907 			printf("unable to get device descriptor (error=%d)\n",
908 			       err);
909 		else
910 			printf("USB device descriptor short read " \
911 				"(expected %i, got %i)\n", tmp, err);
912 		return 1;
913 	}
914 	/* correct le values */
915 	le16_to_cpus(&dev->descriptor.bcdUSB);
916 	le16_to_cpus(&dev->descriptor.idVendor);
917 	le16_to_cpus(&dev->descriptor.idProduct);
918 	le16_to_cpus(&dev->descriptor.bcdDevice);
919 	/* only support for one config for now */
920 	usb_get_configuration_no(dev, &tmpbuf[0], 0);
921 	usb_parse_config(dev, &tmpbuf[0], 0);
922 	usb_set_maxpacket(dev);
923 	/* we set the default configuration here */
924 	if (usb_set_configuration(dev, dev->config.desc.bConfigurationValue)) {
925 		printf("failed to set default configuration " \
926 			"len %d, status %lX\n", dev->act_len, dev->status);
927 		return -1;
928 	}
929 	USB_PRINTF("new device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
930 		   dev->descriptor.iManufacturer, dev->descriptor.iProduct,
931 		   dev->descriptor.iSerialNumber);
932 	memset(dev->mf, 0, sizeof(dev->mf));
933 	memset(dev->prod, 0, sizeof(dev->prod));
934 	memset(dev->serial, 0, sizeof(dev->serial));
935 	if (dev->descriptor.iManufacturer)
936 		usb_string(dev, dev->descriptor.iManufacturer,
937 			   dev->mf, sizeof(dev->mf));
938 	if (dev->descriptor.iProduct)
939 		usb_string(dev, dev->descriptor.iProduct,
940 			   dev->prod, sizeof(dev->prod));
941 	if (dev->descriptor.iSerialNumber)
942 		usb_string(dev, dev->descriptor.iSerialNumber,
943 			   dev->serial, sizeof(dev->serial));
944 	USB_PRINTF("Manufacturer %s\n", dev->mf);
945 	USB_PRINTF("Product      %s\n", dev->prod);
946 	USB_PRINTF("SerialNumber %s\n", dev->serial);
947 	/* now prode if the device is a hub */
948 	usb_hub_probe(dev, 0);
949 	return 0;
950 }
951 
952 /* build device Tree  */
953 static void usb_scan_devices(void)
954 {
955 	int i;
956 	struct usb_device *dev;
957 
958 	/* first make all devices unknown */
959 	for (i = 0; i < USB_MAX_DEVICE; i++) {
960 		memset(&usb_dev[i], 0, sizeof(struct usb_device));
961 		usb_dev[i].devnum = -1;
962 	}
963 	dev_index = 0;
964 	/* device 0 is always present (root hub, so let it analyze) */
965 	dev = usb_alloc_new_device();
966 	if (usb_new_device(dev))
967 		printf("No USB Device found\n");
968 	else
969 		printf("%d USB Device(s) found\n", dev_index);
970 	/* insert "driver" if possible */
971 #ifdef CONFIG_USB_KEYBOARD
972 	drv_usb_kbd_init();
973 #endif
974 	USB_PRINTF("scan end\n");
975 }
976 
977 /* EOF */
978