xref: /openbmc/u-boot/common/usb.c (revision 7dfb0602)
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/compiler.h>
51 #include <linux/ctype.h>
52 #include <asm/byteorder.h>
53 #include <asm/unaligned.h>
54 
55 #include <usb.h>
56 #ifdef CONFIG_4xx
57 #include <asm/4xx_pci.h>
58 #endif
59 
60 #ifdef DEBUG
61 #define USB_DEBUG	1
62 #define USB_HUB_DEBUG	1
63 #else
64 #define USB_DEBUG	0
65 #define USB_HUB_DEBUG	0
66 #endif
67 
68 #define USB_PRINTF(fmt, args...)	debug_cond(USB_DEBUG, fmt, ##args)
69 #define USB_HUB_PRINTF(fmt, args...)	debug_cond(USB_HUB_DEBUG, fmt, ##args)
70 
71 #define USB_BUFSIZ	512
72 
73 static struct usb_device usb_dev[USB_MAX_DEVICE];
74 static int dev_index;
75 static int running;
76 static int asynch_allowed;
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  * Init USB Device
87  */
88 
89 int usb_init(void)
90 {
91 	int result;
92 
93 	running = 0;
94 	dev_index = 0;
95 	asynch_allowed = 1;
96 	usb_hub_reset();
97 	/* init low_level USB */
98 	printf("USB:   ");
99 	result = usb_lowlevel_init();
100 	/* if lowlevel init is OK, scan the bus for devices
101 	 * i.e. search HUBs and configure them */
102 	if (result == 0) {
103 		printf("scanning bus for devices... ");
104 		running = 1;
105 		usb_scan_devices();
106 		usb_started = 1;
107 		return 0;
108 	} else {
109 		printf("Error, couldn't init Lowlevel part\n");
110 		usb_started = 0;
111 		return -1;
112 	}
113 }
114 
115 /******************************************************************************
116  * Stop USB this stops the LowLevel Part and deregisters USB devices.
117  */
118 int usb_stop(void)
119 {
120 	int res = 0;
121 
122 	if (usb_started) {
123 		asynch_allowed = 1;
124 		usb_started = 0;
125 		usb_hub_reset();
126 		res = usb_lowlevel_stop();
127 	}
128 	return res;
129 }
130 
131 /*
132  * disables the asynch behaviour of the control message. This is used for data
133  * transfers that uses the exclusiv access to the control and bulk messages.
134  * Returns the old value so it can be restored later.
135  */
136 int usb_disable_asynch(int disable)
137 {
138 	int old_value = asynch_allowed;
139 
140 	asynch_allowed = !disable;
141 	return old_value;
142 }
143 
144 
145 /*-------------------------------------------------------------------
146  * Message wrappers.
147  *
148  */
149 
150 /*
151  * submits an Interrupt Message
152  */
153 int usb_submit_int_msg(struct usb_device *dev, unsigned long pipe,
154 			void *buffer, int transfer_len, int interval)
155 {
156 	return submit_int_msg(dev, pipe, buffer, transfer_len, interval);
157 }
158 
159 /*
160  * submits a control message and waits for comletion (at least timeout * 1ms)
161  * If timeout is 0, we don't wait for completion (used as example to set and
162  * clear keyboards LEDs). For data transfers, (storage transfers) we don't
163  * allow control messages with 0 timeout, by previousely resetting the flag
164  * asynch_allowed (usb_disable_asynch(1)).
165  * returns the transfered length if OK or -1 if error. The transfered length
166  * and the current status are stored in the dev->act_len and dev->status.
167  */
168 int usb_control_msg(struct usb_device *dev, unsigned int pipe,
169 			unsigned char request, unsigned char requesttype,
170 			unsigned short value, unsigned short index,
171 			void *data, unsigned short size, int timeout)
172 {
173 	ALLOC_CACHE_ALIGN_BUFFER(struct devrequest, setup_packet, 1);
174 
175 	if ((timeout == 0) && (!asynch_allowed)) {
176 		/* request for a asynch control pipe is not allowed */
177 		return -1;
178 	}
179 
180 	/* set setup command */
181 	setup_packet->requesttype = requesttype;
182 	setup_packet->request = request;
183 	setup_packet->value = cpu_to_le16(value);
184 	setup_packet->index = cpu_to_le16(index);
185 	setup_packet->length = cpu_to_le16(size);
186 	USB_PRINTF("usb_control_msg: request: 0x%X, requesttype: 0x%X, " \
187 		   "value 0x%X index 0x%X length 0x%X\n",
188 		   request, requesttype, value, index, size);
189 	dev->status = USB_ST_NOT_PROC; /*not yet processed */
190 
191 	submit_control_msg(dev, pipe, data, size, setup_packet);
192 	if (timeout == 0)
193 		return (int)size;
194 
195 	/*
196 	 * Wait for status to update until timeout expires, USB driver
197 	 * interrupt handler may set the status when the USB operation has
198 	 * been completed.
199 	 */
200 	while (timeout--) {
201 		if (!((volatile unsigned long)dev->status & USB_ST_NOT_PROC))
202 			break;
203 		mdelay(1);
204 	}
205 	if (dev->status)
206 		return -1;
207 
208 	return dev->act_len;
209 
210 }
211 
212 /*-------------------------------------------------------------------
213  * submits bulk message, and waits for completion. returns 0 if Ok or
214  * -1 if Error.
215  * synchronous behavior
216  */
217 int usb_bulk_msg(struct usb_device *dev, unsigned int pipe,
218 			void *data, int len, int *actual_length, int timeout)
219 {
220 	if (len < 0)
221 		return -1;
222 	dev->status = USB_ST_NOT_PROC; /*not yet processed */
223 	submit_bulk_msg(dev, pipe, data, len);
224 	while (timeout--) {
225 		if (!((volatile unsigned long)dev->status & USB_ST_NOT_PROC))
226 			break;
227 		mdelay(1);
228 	}
229 	*actual_length = dev->act_len;
230 	if (dev->status == 0)
231 		return 0;
232 	else
233 		return -1;
234 }
235 
236 
237 /*-------------------------------------------------------------------
238  * Max Packet stuff
239  */
240 
241 /*
242  * returns the max packet size, depending on the pipe direction and
243  * the configurations values
244  */
245 int usb_maxpacket(struct usb_device *dev, unsigned long pipe)
246 {
247 	/* direction is out -> use emaxpacket out */
248 	if ((pipe & USB_DIR_IN) == 0)
249 		return dev->epmaxpacketout[((pipe>>15) & 0xf)];
250 	else
251 		return dev->epmaxpacketin[((pipe>>15) & 0xf)];
252 }
253 
254 /*
255  * The routine usb_set_maxpacket_ep() is extracted from the loop of routine
256  * usb_set_maxpacket(), because the optimizer of GCC 4.x chokes on this routine
257  * when it is inlined in 1 single routine. What happens is that the register r3
258  * is used as loop-count 'i', but gets overwritten later on.
259  * This is clearly a compiler bug, but it is easier to workaround it here than
260  * to update the compiler (Occurs with at least several GCC 4.{1,2},x
261  * CodeSourcery compilers like e.g. 2007q3, 2008q1, 2008q3 lite editions on ARM)
262  *
263  * NOTE: Similar behaviour was observed with GCC4.6 on ARMv5.
264  */
265 static void noinline
266 usb_set_maxpacket_ep(struct usb_device *dev, int if_idx, int ep_idx)
267 {
268 	int b;
269 	struct usb_endpoint_descriptor *ep;
270 	u16 ep_wMaxPacketSize;
271 
272 	ep = &dev->config.if_desc[if_idx].ep_desc[ep_idx];
273 
274 	b = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
275 	ep_wMaxPacketSize = get_unaligned(&ep->wMaxPacketSize);
276 
277 	if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
278 						USB_ENDPOINT_XFER_CONTROL) {
279 		/* Control => bidirectional */
280 		dev->epmaxpacketout[b] = ep_wMaxPacketSize;
281 		dev->epmaxpacketin[b] = ep_wMaxPacketSize;
282 		USB_PRINTF("##Control EP epmaxpacketout/in[%d] = %d\n",
283 			   b, dev->epmaxpacketin[b]);
284 	} else {
285 		if ((ep->bEndpointAddress & 0x80) == 0) {
286 			/* OUT Endpoint */
287 			if (ep_wMaxPacketSize > dev->epmaxpacketout[b]) {
288 				dev->epmaxpacketout[b] = ep_wMaxPacketSize;
289 				USB_PRINTF("##EP epmaxpacketout[%d] = %d\n",
290 					   b, dev->epmaxpacketout[b]);
291 			}
292 		} else {
293 			/* IN Endpoint */
294 			if (ep_wMaxPacketSize > dev->epmaxpacketin[b]) {
295 				dev->epmaxpacketin[b] = ep_wMaxPacketSize;
296 				USB_PRINTF("##EP epmaxpacketin[%d] = %d\n",
297 					   b, dev->epmaxpacketin[b]);
298 			}
299 		} /* if out */
300 	} /* if control */
301 }
302 
303 /*
304  * set the max packed value of all endpoints in the given configuration
305  */
306 static int usb_set_maxpacket(struct usb_device *dev)
307 {
308 	int i, ii;
309 
310 	for (i = 0; i < dev->config.desc.bNumInterfaces; i++)
311 		for (ii = 0; ii < dev->config.if_desc[i].desc.bNumEndpoints; ii++)
312 			usb_set_maxpacket_ep(dev, i, ii);
313 
314 	return 0;
315 }
316 
317 /*******************************************************************************
318  * Parse the config, located in buffer, and fills the dev->config structure.
319  * Note that all little/big endian swapping are done automatically.
320  */
321 static int usb_parse_config(struct usb_device *dev,
322 			unsigned char *buffer, int cfgno)
323 {
324 	struct usb_descriptor_header *head;
325 	int index, ifno, epno, curr_if_num;
326 	int i;
327 	u16 ep_wMaxPacketSize;
328 
329 	ifno = -1;
330 	epno = -1;
331 	curr_if_num = -1;
332 
333 	dev->configno = cfgno;
334 	head = (struct usb_descriptor_header *) &buffer[0];
335 	if (head->bDescriptorType != USB_DT_CONFIG) {
336 		printf(" ERROR: NOT USB_CONFIG_DESC %x\n",
337 			head->bDescriptorType);
338 		return -1;
339 	}
340 	memcpy(&dev->config, buffer, buffer[0]);
341 	le16_to_cpus(&(dev->config.desc.wTotalLength));
342 	dev->config.no_of_if = 0;
343 
344 	index = dev->config.desc.bLength;
345 	/* Ok the first entry must be a configuration entry,
346 	 * now process the others */
347 	head = (struct usb_descriptor_header *) &buffer[index];
348 	while (index + 1 < dev->config.desc.wTotalLength) {
349 		switch (head->bDescriptorType) {
350 		case USB_DT_INTERFACE:
351 			if (((struct usb_interface_descriptor *) \
352 			     &buffer[index])->bInterfaceNumber != curr_if_num) {
353 				/* this is a new interface, copy new desc */
354 				ifno = dev->config.no_of_if;
355 				dev->config.no_of_if++;
356 				memcpy(&dev->config.if_desc[ifno],
357 					&buffer[index], buffer[index]);
358 				dev->config.if_desc[ifno].no_of_ep = 0;
359 				dev->config.if_desc[ifno].num_altsetting = 1;
360 				curr_if_num =
361 				     dev->config.if_desc[ifno].desc.bInterfaceNumber;
362 			} else {
363 				/* found alternate setting for the interface */
364 				dev->config.if_desc[ifno].num_altsetting++;
365 			}
366 			break;
367 		case USB_DT_ENDPOINT:
368 			epno = dev->config.if_desc[ifno].no_of_ep;
369 			/* found an endpoint */
370 			dev->config.if_desc[ifno].no_of_ep++;
371 			memcpy(&dev->config.if_desc[ifno].ep_desc[epno],
372 				&buffer[index], buffer[index]);
373 			ep_wMaxPacketSize = get_unaligned(&dev->config.\
374 							if_desc[ifno].\
375 							ep_desc[epno].\
376 							wMaxPacketSize);
377 			put_unaligned(le16_to_cpu(ep_wMaxPacketSize),
378 					&dev->config.\
379 					if_desc[ifno].\
380 					ep_desc[epno].\
381 					wMaxPacketSize);
382 			USB_PRINTF("if %d, ep %d\n", ifno, epno);
383 			break;
384 		default:
385 			if (head->bLength == 0)
386 				return 1;
387 
388 			USB_PRINTF("unknown Description Type : %x\n",
389 				   head->bDescriptorType);
390 
391 			{
392 #ifdef USB_DEBUG
393 				unsigned char *ch = (unsigned char *)head;
394 #endif
395 				for (i = 0; i < head->bLength; i++)
396 					USB_PRINTF("%02X ", *ch++);
397 				USB_PRINTF("\n\n\n");
398 			}
399 			break;
400 		}
401 		index += head->bLength;
402 		head = (struct usb_descriptor_header *)&buffer[index];
403 	}
404 	return 1;
405 }
406 
407 /***********************************************************************
408  * Clears an endpoint
409  * endp: endpoint number in bits 0-3;
410  * direction flag in bit 7 (1 = IN, 0 = OUT)
411  */
412 int usb_clear_halt(struct usb_device *dev, int pipe)
413 {
414 	int result;
415 	int endp = usb_pipeendpoint(pipe)|(usb_pipein(pipe)<<7);
416 
417 	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
418 				 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 0,
419 				 endp, NULL, 0, USB_CNTL_TIMEOUT * 3);
420 
421 	/* don't clear if failed */
422 	if (result < 0)
423 		return result;
424 
425 	/*
426 	 * NOTE: we do not get status and verify reset was successful
427 	 * as some devices are reported to lock up upon this check..
428 	 */
429 
430 	usb_endpoint_running(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe));
431 
432 	/* toggle is reset on clear */
433 	usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0);
434 	return 0;
435 }
436 
437 
438 /**********************************************************************
439  * get_descriptor type
440  */
441 static int usb_get_descriptor(struct usb_device *dev, unsigned char type,
442 			unsigned char index, void *buf, int size)
443 {
444 	int res;
445 	res = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
446 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
447 			(type << 8) + index, 0,
448 			buf, size, USB_CNTL_TIMEOUT);
449 	return res;
450 }
451 
452 /**********************************************************************
453  * gets configuration cfgno and store it in the buffer
454  */
455 int usb_get_configuration_no(struct usb_device *dev,
456 			     unsigned char *buffer, int cfgno)
457 {
458 	int result;
459 	unsigned int tmp;
460 	struct usb_configuration_descriptor *config;
461 
462 	config = (struct usb_configuration_descriptor *)&buffer[0];
463 	result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, 9);
464 	if (result < 9) {
465 		if (result < 0)
466 			printf("unable to get descriptor, error %lX\n",
467 				dev->status);
468 		else
469 			printf("config descriptor too short " \
470 				"(expected %i, got %i)\n", 9, result);
471 		return -1;
472 	}
473 	tmp = le16_to_cpu(config->wTotalLength);
474 
475 	if (tmp > USB_BUFSIZ) {
476 		USB_PRINTF("usb_get_configuration_no: failed to get " \
477 			   "descriptor - too long: %d\n", tmp);
478 		return -1;
479 	}
480 
481 	result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno, buffer, tmp);
482 	USB_PRINTF("get_conf_no %d Result %d, wLength %d\n",
483 		   cfgno, result, tmp);
484 	return result;
485 }
486 
487 /********************************************************************
488  * set address of a device to the value in dev->devnum.
489  * This can only be done by addressing the device via the default address (0)
490  */
491 static int usb_set_address(struct usb_device *dev)
492 {
493 	int res;
494 
495 	USB_PRINTF("set address %d\n", dev->devnum);
496 	res = usb_control_msg(dev, usb_snddefctrl(dev),
497 				USB_REQ_SET_ADDRESS, 0,
498 				(dev->devnum), 0,
499 				NULL, 0, USB_CNTL_TIMEOUT);
500 	return res;
501 }
502 
503 /********************************************************************
504  * set interface number to interface
505  */
506 int usb_set_interface(struct usb_device *dev, int interface, int alternate)
507 {
508 	struct usb_interface *if_face = NULL;
509 	int ret, i;
510 
511 	for (i = 0; i < dev->config.desc.bNumInterfaces; i++) {
512 		if (dev->config.if_desc[i].desc.bInterfaceNumber == interface) {
513 			if_face = &dev->config.if_desc[i];
514 			break;
515 		}
516 	}
517 	if (!if_face) {
518 		printf("selecting invalid interface %d", interface);
519 		return -1;
520 	}
521 	/*
522 	 * We should return now for devices with only one alternate setting.
523 	 * According to 9.4.10 of the Universal Serial Bus Specification
524 	 * Revision 2.0 such devices can return with a STALL. This results in
525 	 * some USB sticks timeouting during initialization and then being
526 	 * unusable in U-Boot.
527 	 */
528 	if (if_face->num_altsetting == 1)
529 		return 0;
530 
531 	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
532 				USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
533 				alternate, interface, NULL, 0,
534 				USB_CNTL_TIMEOUT * 5);
535 	if (ret < 0)
536 		return ret;
537 
538 	return 0;
539 }
540 
541 /********************************************************************
542  * set configuration number to configuration
543  */
544 static int usb_set_configuration(struct usb_device *dev, int configuration)
545 {
546 	int res;
547 	USB_PRINTF("set configuration %d\n", configuration);
548 	/* set setup command */
549 	res = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
550 				USB_REQ_SET_CONFIGURATION, 0,
551 				configuration, 0,
552 				NULL, 0, USB_CNTL_TIMEOUT);
553 	if (res == 0) {
554 		dev->toggle[0] = 0;
555 		dev->toggle[1] = 0;
556 		return 0;
557 	} else
558 		return -1;
559 }
560 
561 /********************************************************************
562  * set protocol to protocol
563  */
564 int usb_set_protocol(struct usb_device *dev, int ifnum, int protocol)
565 {
566 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
567 		USB_REQ_SET_PROTOCOL, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
568 		protocol, ifnum, NULL, 0, USB_CNTL_TIMEOUT);
569 }
570 
571 /********************************************************************
572  * set idle
573  */
574 int usb_set_idle(struct usb_device *dev, int ifnum, int duration, int report_id)
575 {
576 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
577 		USB_REQ_SET_IDLE, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
578 		(duration << 8) | report_id, ifnum, NULL, 0, USB_CNTL_TIMEOUT);
579 }
580 
581 /********************************************************************
582  * get report
583  */
584 int usb_get_report(struct usb_device *dev, int ifnum, unsigned char type,
585 		   unsigned char id, void *buf, int size)
586 {
587 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
588 			USB_REQ_GET_REPORT,
589 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
590 			(type << 8) + id, ifnum, buf, size, USB_CNTL_TIMEOUT);
591 }
592 
593 /********************************************************************
594  * get class descriptor
595  */
596 int usb_get_class_descriptor(struct usb_device *dev, int ifnum,
597 		unsigned char type, unsigned char id, void *buf, int size)
598 {
599 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
600 		USB_REQ_GET_DESCRIPTOR, USB_RECIP_INTERFACE | USB_DIR_IN,
601 		(type << 8) + id, ifnum, buf, size, USB_CNTL_TIMEOUT);
602 }
603 
604 /********************************************************************
605  * get string index in buffer
606  */
607 static int usb_get_string(struct usb_device *dev, unsigned short langid,
608 		   unsigned char index, void *buf, int size)
609 {
610 	int i;
611 	int result;
612 
613 	for (i = 0; i < 3; ++i) {
614 		/* some devices are flaky */
615 		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
616 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
617 			(USB_DT_STRING << 8) + index, langid, buf, size,
618 			USB_CNTL_TIMEOUT);
619 
620 		if (result > 0)
621 			break;
622 	}
623 
624 	return result;
625 }
626 
627 
628 static void usb_try_string_workarounds(unsigned char *buf, int *length)
629 {
630 	int newlength, oldlength = *length;
631 
632 	for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
633 		if (!isprint(buf[newlength]) || buf[newlength + 1])
634 			break;
635 
636 	if (newlength > 2) {
637 		buf[0] = newlength;
638 		*length = newlength;
639 	}
640 }
641 
642 
643 static int usb_string_sub(struct usb_device *dev, unsigned int langid,
644 		unsigned int index, unsigned char *buf)
645 {
646 	int rc;
647 
648 	/* Try to read the string descriptor by asking for the maximum
649 	 * possible number of bytes */
650 	rc = usb_get_string(dev, langid, index, buf, 255);
651 
652 	/* If that failed try to read the descriptor length, then
653 	 * ask for just that many bytes */
654 	if (rc < 2) {
655 		rc = usb_get_string(dev, langid, index, buf, 2);
656 		if (rc == 2)
657 			rc = usb_get_string(dev, langid, index, buf, buf[0]);
658 	}
659 
660 	if (rc >= 2) {
661 		if (!buf[0] && !buf[1])
662 			usb_try_string_workarounds(buf, &rc);
663 
664 		/* There might be extra junk at the end of the descriptor */
665 		if (buf[0] < rc)
666 			rc = buf[0];
667 
668 		rc = rc - (rc & 1); /* force a multiple of two */
669 	}
670 
671 	if (rc < 2)
672 		rc = -1;
673 
674 	return rc;
675 }
676 
677 
678 /********************************************************************
679  * usb_string:
680  * Get string index and translate it to ascii.
681  * returns string length (> 0) or error (< 0)
682  */
683 int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
684 {
685 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, mybuf, USB_BUFSIZ);
686 	unsigned char *tbuf;
687 	int err;
688 	unsigned int u, idx;
689 
690 	if (size <= 0 || !buf || !index)
691 		return -1;
692 	buf[0] = 0;
693 	tbuf = &mybuf[0];
694 
695 	/* get langid for strings if it's not yet known */
696 	if (!dev->have_langid) {
697 		err = usb_string_sub(dev, 0, 0, tbuf);
698 		if (err < 0) {
699 			USB_PRINTF("error getting string descriptor 0 " \
700 				   "(error=%lx)\n", dev->status);
701 			return -1;
702 		} else if (tbuf[0] < 4) {
703 			USB_PRINTF("string descriptor 0 too short\n");
704 			return -1;
705 		} else {
706 			dev->have_langid = -1;
707 			dev->string_langid = tbuf[2] | (tbuf[3] << 8);
708 				/* always use the first langid listed */
709 			USB_PRINTF("USB device number %d default " \
710 				   "language ID 0x%x\n",
711 				   dev->devnum, dev->string_langid);
712 		}
713 	}
714 
715 	err = usb_string_sub(dev, dev->string_langid, index, tbuf);
716 	if (err < 0)
717 		return err;
718 
719 	size--;		/* leave room for trailing NULL char in output buffer */
720 	for (idx = 0, u = 2; u < err; u += 2) {
721 		if (idx >= size)
722 			break;
723 		if (tbuf[u+1])			/* high byte */
724 			buf[idx++] = '?';  /* non-ASCII character */
725 		else
726 			buf[idx++] = tbuf[u];
727 	}
728 	buf[idx] = 0;
729 	err = idx;
730 	return err;
731 }
732 
733 
734 /********************************************************************
735  * USB device handling:
736  * the USB device are static allocated [USB_MAX_DEVICE].
737  */
738 
739 
740 /* returns a pointer to the device with the index [index].
741  * if the device is not assigned (dev->devnum==-1) returns NULL
742  */
743 struct usb_device *usb_get_dev_index(int index)
744 {
745 	if (usb_dev[index].devnum == -1)
746 		return NULL;
747 	else
748 		return &usb_dev[index];
749 }
750 
751 
752 /* returns a pointer of a new device structure or NULL, if
753  * no device struct is available
754  */
755 struct usb_device *usb_alloc_new_device(void)
756 {
757 	int i;
758 	USB_PRINTF("New Device %d\n", dev_index);
759 	if (dev_index == USB_MAX_DEVICE) {
760 		printf("ERROR, too many USB Devices, max=%d\n", USB_MAX_DEVICE);
761 		return NULL;
762 	}
763 	/* default Address is 0, real addresses start with 1 */
764 	usb_dev[dev_index].devnum = dev_index + 1;
765 	usb_dev[dev_index].maxchild = 0;
766 	for (i = 0; i < USB_MAXCHILDREN; i++)
767 		usb_dev[dev_index].children[i] = NULL;
768 	usb_dev[dev_index].parent = NULL;
769 	dev_index++;
770 	return &usb_dev[dev_index - 1];
771 }
772 
773 
774 /*
775  * By the time we get here, the device has gotten a new device ID
776  * and is in the default state. We need to identify the thing and
777  * get the ball rolling..
778  *
779  * Returns 0 for success, != 0 for error.
780  */
781 int usb_new_device(struct usb_device *dev)
782 {
783 	int addr, err;
784 	int tmp;
785 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
786 
787 	/* We still haven't set the Address yet */
788 	addr = dev->devnum;
789 	dev->devnum = 0;
790 
791 #ifdef CONFIG_LEGACY_USB_INIT_SEQ
792 	/* this is the old and known way of initializing devices, it is
793 	 * different than what Windows and Linux are doing. Windows and Linux
794 	 * both retrieve 64 bytes while reading the device descriptor
795 	 * Several USB stick devices report ERR: CTL_TIMEOUT, caused by an
796 	 * invalid header while reading 8 bytes as device descriptor. */
797 	dev->descriptor.bMaxPacketSize0 = 8;	    /* Start off at 8 bytes  */
798 	dev->maxpacketsize = PACKET_SIZE_8;
799 	dev->epmaxpacketin[0] = 8;
800 	dev->epmaxpacketout[0] = 8;
801 
802 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
803 	if (err < 8) {
804 		printf("\n      USB device not responding, " \
805 		       "giving up (status=%lX)\n", dev->status);
806 		return 1;
807 	}
808 #else
809 	/* This is a Windows scheme of initialization sequence, with double
810 	 * reset of the device (Linux uses the same sequence)
811 	 * Some equipment is said to work only with such init sequence; this
812 	 * patch is based on the work by Alan Stern:
813 	 * http://sourceforge.net/mailarchive/forum.php?
814 	 * thread_id=5729457&forum_id=5398
815 	 */
816 	struct usb_device_descriptor *desc;
817 	int port = -1;
818 	struct usb_device *parent = dev->parent;
819 	unsigned short portstatus;
820 
821 	/* send 64-byte GET-DEVICE-DESCRIPTOR request.  Since the descriptor is
822 	 * only 18 bytes long, this will terminate with a short packet.  But if
823 	 * the maxpacket size is 8 or 16 the device may be waiting to transmit
824 	 * some more, or keeps on retransmitting the 8 byte header. */
825 
826 	desc = (struct usb_device_descriptor *)tmpbuf;
827 	dev->descriptor.bMaxPacketSize0 = 64;	    /* Start off at 64 bytes  */
828 	/* Default to 64 byte max packet size */
829 	dev->maxpacketsize = PACKET_SIZE_64;
830 	dev->epmaxpacketin[0] = 64;
831 	dev->epmaxpacketout[0] = 64;
832 
833 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
834 	if (err < 0) {
835 		USB_PRINTF("usb_new_device: usb_get_descriptor() failed\n");
836 		return 1;
837 	}
838 
839 	dev->descriptor.bMaxPacketSize0 = desc->bMaxPacketSize0;
840 
841 	/* find the port number we're at */
842 	if (parent) {
843 		int j;
844 
845 		for (j = 0; j < parent->maxchild; j++) {
846 			if (parent->children[j] == dev) {
847 				port = j;
848 				break;
849 			}
850 		}
851 		if (port < 0) {
852 			printf("usb_new_device:cannot locate device's port.\n");
853 			return 1;
854 		}
855 
856 		/* reset the port for the second time */
857 		err = hub_port_reset(dev->parent, port, &portstatus);
858 		if (err < 0) {
859 			printf("\n     Couldn't reset port %i\n", port);
860 			return 1;
861 		}
862 	}
863 #endif
864 
865 	dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
866 	dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
867 	switch (dev->descriptor.bMaxPacketSize0) {
868 	case 8:
869 		dev->maxpacketsize  = PACKET_SIZE_8;
870 		break;
871 	case 16:
872 		dev->maxpacketsize = PACKET_SIZE_16;
873 		break;
874 	case 32:
875 		dev->maxpacketsize = PACKET_SIZE_32;
876 		break;
877 	case 64:
878 		dev->maxpacketsize = PACKET_SIZE_64;
879 		break;
880 	}
881 	dev->devnum = addr;
882 
883 	err = usb_set_address(dev); /* set address */
884 
885 	if (err < 0) {
886 		printf("\n      USB device not accepting new address " \
887 			"(error=%lX)\n", dev->status);
888 		return 1;
889 	}
890 
891 	mdelay(10);	/* Let the SET_ADDRESS settle */
892 
893 	tmp = sizeof(dev->descriptor);
894 
895 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
896 				 &dev->descriptor, sizeof(dev->descriptor));
897 	if (err < tmp) {
898 		if (err < 0)
899 			printf("unable to get device descriptor (error=%d)\n",
900 			       err);
901 		else
902 			printf("USB device descriptor short read " \
903 				"(expected %i, got %i)\n", tmp, err);
904 		return 1;
905 	}
906 	/* correct le values */
907 	le16_to_cpus(&dev->descriptor.bcdUSB);
908 	le16_to_cpus(&dev->descriptor.idVendor);
909 	le16_to_cpus(&dev->descriptor.idProduct);
910 	le16_to_cpus(&dev->descriptor.bcdDevice);
911 	/* only support for one config for now */
912 	usb_get_configuration_no(dev, tmpbuf, 0);
913 	usb_parse_config(dev, tmpbuf, 0);
914 	usb_set_maxpacket(dev);
915 	/* we set the default configuration here */
916 	if (usb_set_configuration(dev, dev->config.desc.bConfigurationValue)) {
917 		printf("failed to set default configuration " \
918 			"len %d, status %lX\n", dev->act_len, dev->status);
919 		return -1;
920 	}
921 	USB_PRINTF("new device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
922 		   dev->descriptor.iManufacturer, dev->descriptor.iProduct,
923 		   dev->descriptor.iSerialNumber);
924 	memset(dev->mf, 0, sizeof(dev->mf));
925 	memset(dev->prod, 0, sizeof(dev->prod));
926 	memset(dev->serial, 0, sizeof(dev->serial));
927 	if (dev->descriptor.iManufacturer)
928 		usb_string(dev, dev->descriptor.iManufacturer,
929 			   dev->mf, sizeof(dev->mf));
930 	if (dev->descriptor.iProduct)
931 		usb_string(dev, dev->descriptor.iProduct,
932 			   dev->prod, sizeof(dev->prod));
933 	if (dev->descriptor.iSerialNumber)
934 		usb_string(dev, dev->descriptor.iSerialNumber,
935 			   dev->serial, sizeof(dev->serial));
936 	USB_PRINTF("Manufacturer %s\n", dev->mf);
937 	USB_PRINTF("Product      %s\n", dev->prod);
938 	USB_PRINTF("SerialNumber %s\n", dev->serial);
939 	/* now prode if the device is a hub */
940 	usb_hub_probe(dev, 0);
941 	return 0;
942 }
943 
944 /* build device Tree  */
945 static void usb_scan_devices(void)
946 {
947 	int i;
948 	struct usb_device *dev;
949 
950 	/* first make all devices unknown */
951 	for (i = 0; i < USB_MAX_DEVICE; i++) {
952 		memset(&usb_dev[i], 0, sizeof(struct usb_device));
953 		usb_dev[i].devnum = -1;
954 	}
955 	dev_index = 0;
956 	/* device 0 is always present (root hub, so let it analyze) */
957 	dev = usb_alloc_new_device();
958 	if (usb_new_device(dev))
959 		printf("No USB Device found\n");
960 	else
961 		printf("%d USB Device(s) found\n", dev_index);
962 	/* insert "driver" if possible */
963 #ifdef CONFIG_USB_KEYBOARD
964 	drv_usb_kbd_init();
965 #endif
966 	USB_PRINTF("scan end\n");
967 }
968 
969 /* EOF */
970