usb_hub.c 21 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795
/*
 * Most of this source has been derived from the Linux USB
 * project:
 * (C) Copyright Linus Torvalds 1999
 * (C) Copyright Johannes Erdfelt 1999-2001
 * (C) Copyright Andreas Gal 1999
 * (C) Copyright Gregory P. Smith 1999
 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000 (kernel hotplug, usb_device_id)
 * (C) Copyright Yggdrasil Computing, Inc. 2000
 *     (usb_device_id matching changes by Adam J. Richter)
 *
 * Adapted for U-Boot:
 * (C) Copyright 2001 Denis Peter, MPL AG Switzerland
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/****************************************************************************
 * HUB "Driver"
 * Probes device for being a hub and configurate it
 */

#include <common.h>
#include <command.h>
#include <dm.h>
#include <errno.h>
#include <memalign.h>
#include <asm/processor.h>
#include <asm/unaligned.h>
#include <linux/ctype.h>
#include <linux/list.h>
#include <asm/byteorder.h>
#ifdef CONFIG_SANDBOX
#include <asm/state.h>
#endif
#include <asm/unaligned.h>

DECLARE_GLOBAL_DATA_PTR;

#include <usb.h>

#define USB_BUFSIZ	512

#define HUB_SHORT_RESET_TIME	20
#define HUB_LONG_RESET_TIME	200

#define PORT_OVERCURRENT_MAX_SCAN_COUNT		3

struct usb_device_scan {
	struct usb_device *dev;		/* USB hub device to scan */
	struct usb_hub_device *hub;	/* USB hub struct */
	int port;			/* USB port to scan */
	struct list_head list;
};

/* TODO(sjg@chromium.org): Remove this when CONFIG_DM_USB is defined */
static struct usb_hub_device hub_dev[USB_MAX_HUB];
static int usb_hub_index;
static LIST_HEAD(usb_scan_list);

__weak void usb_hub_reset_devices(int port)
{
	return;
}

static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
		USB_DT_HUB << 8, 0, data, size, USB_CNTL_TIMEOUT);
}

static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
{
	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
				port, NULL, 0, USB_CNTL_TIMEOUT);
}

static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
{
	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
				port, NULL, 0, USB_CNTL_TIMEOUT);
}

static int usb_get_hub_status(struct usb_device *dev, void *data)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
}

int usb_get_port_status(struct usb_device *dev, int port, void *data)
{
	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
}


static void usb_hub_power_on(struct usb_hub_device *hub)
{
	int i;
	struct usb_device *dev;
	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
	const char *env;

	dev = hub->pusb_dev;

	debug("enabling power on all ports\n");
	for (i = 0; i < dev->maxchild; i++) {
		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
		debug("port %d returns %lX\n", i + 1, dev->status);
	}

#ifdef CONFIG_SANDBOX
	/*
	 * Don't set timeout / delay values here. This results
	 * in these values still being reset to 0.
	 */
	if (state_get_skip_delays())
		return;
#endif

	/*
	 * Wait for power to become stable,
	 * plus spec-defined max time for device to connect
	 * but allow this time to be increased via env variable as some
	 * devices break the spec and require longer warm-up times
	 */
	env = getenv("usb_pgood_delay");
	if (env)
		pgood_delay = max(pgood_delay,
			          (unsigned)simple_strtol(env, NULL, 0));
	debug("pgood_delay=%dms\n", pgood_delay);

	/*
	 * Do a minimum delay of the larger value of 100ms or pgood_delay
	 * so that the power can stablize before the devices are queried
	 */
	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);

	/*
	 * Record the power-on timeout here. The max. delay (timeout)
	 * will be done based on this value in the USB port loop in
	 * usb_hub_configure() later.
	 */
	hub->connect_timeout = hub->query_delay + 1000;
	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
	      dev->devnum, max(100, (int)pgood_delay),
	      max(100, (int)pgood_delay) + 1000);
}

void usb_hub_reset(void)
{
	usb_hub_index = 0;

	/* Zero out global hub_dev in case its re-used again */
	memset(hub_dev, 0, sizeof(hub_dev));
}

static struct usb_hub_device *usb_hub_allocate(void)
{
	if (usb_hub_index < USB_MAX_HUB)
		return &hub_dev[usb_hub_index++];

	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
	return NULL;
}

#define MAX_TRIES 5

static inline char *portspeed(int portstatus)
{
	char *speed_str;

	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
	case USB_PORT_STAT_SUPER_SPEED:
		speed_str = "5 Gb/s";
		break;
	case USB_PORT_STAT_HIGH_SPEED:
		speed_str = "480 Mb/s";
		break;
	case USB_PORT_STAT_LOW_SPEED:
		speed_str = "1.5 Mb/s";
		break;
	default:
		speed_str = "12 Mb/s";
		break;
	}

	return speed_str;
}

int legacy_hub_port_reset(struct usb_device *dev, int port,
			unsigned short *portstat)
{
	int err, tries;
	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
	unsigned short portstatus, portchange;
	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */

#ifdef CONFIG_DM_USB
	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
	      port + 1);
#else
	debug("%s: resetting port %d...\n", __func__, port + 1);
#endif
	for (tries = 0; tries < MAX_TRIES; tries++) {
		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
		if (err < 0)
			return err;

		mdelay(delay);

		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
			debug("get_port_status failed status %lX\n",
			      dev->status);
			return -1;
		}
		portstatus = le16_to_cpu(portsts->wPortStatus);
		portchange = le16_to_cpu(portsts->wPortChange);

		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
							portspeed(portstatus));

		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
		      "  USB_PORT_STAT_ENABLE %d\n",
		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);

		/*
		 * Perhaps we should check for the following here:
		 * - C_CONNECTION hasn't been set.
		 * - CONNECTION is still set.
		 *
		 * Doing so would ensure that the device is still connected
		 * to the bus, and hasn't been unplugged or replaced while the
		 * USB bus reset was going on.
		 *
		 * However, if we do that, then (at least) a San Disk Ultra
		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
		 * Tegra Jetson TK1 board. For some reason, the device appears
		 * to briefly drop off the bus when this second bus reset is
		 * executed, yet if we retry this loop, it'll eventually come
		 * back after another reset or two.
		 */

		if (portstatus & USB_PORT_STAT_ENABLE)
			break;

		/* Switch to long reset delay for the next round */
		delay = HUB_LONG_RESET_TIME;
	}

	if (tries == MAX_TRIES) {
		debug("Cannot enable port %i after %i retries, " \
		      "disabling port.\n", port + 1, MAX_TRIES);
		debug("Maybe the USB cable is bad?\n");
		return -1;
	}

	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
	*portstat = portstatus;
	return 0;
}

#ifdef CONFIG_DM_USB
int hub_port_reset(struct udevice *dev, int port, unsigned short *portstat)
{
	struct usb_device *udev = dev_get_parent_priv(dev);

	return legacy_hub_port_reset(udev, port, portstat);
}
#endif

int usb_hub_port_connect_change(struct usb_device *dev, int port)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
	unsigned short portstatus;
	int ret, speed;

	/* Check status */
	ret = usb_get_port_status(dev, port + 1, portsts);
	if (ret < 0) {
		debug("get_port_status failed\n");
		return ret;
	}

	portstatus = le16_to_cpu(portsts->wPortStatus);
	debug("portstatus %x, change %x, %s\n",
	      portstatus,
	      le16_to_cpu(portsts->wPortChange),
	      portspeed(portstatus));

	/* Clear the connection change status */
	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);

	/* Disconnect any existing devices under this port */
	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
	    usb_device_has_child_on_port(dev, port)) {
		debug("usb_disconnect(&hub->children[port]);\n");
		/* Return now if nothing is connected */
		if (!(portstatus & USB_PORT_STAT_CONNECTION))
			return -ENOTCONN;
	}

	/* Reset the port */
	ret = legacy_hub_port_reset(dev, port, &portstatus);
	if (ret < 0) {
		if (ret != -ENXIO)
			printf("cannot reset port %i!?\n", port + 1);
		return ret;
	}

	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
	case USB_PORT_STAT_SUPER_SPEED:
		speed = USB_SPEED_SUPER;
		break;
	case USB_PORT_STAT_HIGH_SPEED:
		speed = USB_SPEED_HIGH;
		break;
	case USB_PORT_STAT_LOW_SPEED:
		speed = USB_SPEED_LOW;
		break;
	default:
		speed = USB_SPEED_FULL;
		break;
	}

#ifdef CONFIG_DM_USB
	struct udevice *child;

	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
#else
	struct usb_device *usb;

	ret = usb_alloc_new_device(dev->controller, &usb);
	if (ret) {
		printf("cannot create new device: ret=%d", ret);
		return ret;
	}

	dev->children[port] = usb;
	usb->speed = speed;
	usb->parent = dev;
	usb->portnr = port + 1;
	/* Run it through the hoops (find a driver, etc) */
	ret = usb_new_device(usb);
	if (ret < 0) {
		/* Woops, disable the port */
		usb_free_device(dev->controller);
		dev->children[port] = NULL;
	}
#endif
	if (ret < 0) {
		debug("hub: disabling port %d\n", port + 1);
		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
	}

	return ret;
}

static int usb_scan_port(struct usb_device_scan *usb_scan)
{
	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
	unsigned short portstatus;
	unsigned short portchange;
	struct usb_device *dev;
	struct usb_hub_device *hub;
	int ret = 0;
	int i;

	dev = usb_scan->dev;
	hub = usb_scan->hub;
	i = usb_scan->port;

	/*
	 * Don't talk to the device before the query delay is expired.
	 * This is needed for voltages to stabalize.
	 */
	if (get_timer(0) < hub->query_delay)
		return 0;

	ret = usb_get_port_status(dev, i + 1, portsts);
	if (ret < 0) {
		debug("get_port_status failed\n");
		if (get_timer(0) >= hub->connect_timeout) {
			debug("devnum=%d port=%d: timeout\n",
			      dev->devnum, i + 1);
			/* Remove this device from scanning list */
			list_del(&usb_scan->list);
			free(usb_scan);
			return 0;
		}
		return 0;
	}

	portstatus = le16_to_cpu(portsts->wPortStatus);
	portchange = le16_to_cpu(portsts->wPortChange);
	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);

	/*
	 * No connection change happened, wait a bit more.
	 *
	 * For some situation, the hub reports no connection change but a
	 * device is connected to the port (eg: CCS bit is set but CSC is not
	 * in the PORTSC register of a root hub), ignore such case.
	 */
	if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
	    !(portstatus & USB_PORT_STAT_CONNECTION)) {
		if (get_timer(0) >= hub->connect_timeout) {
			debug("devnum=%d port=%d: timeout\n",
			      dev->devnum, i + 1);
			/* Remove this device from scanning list */
			list_del(&usb_scan->list);
			free(usb_scan);
			return 0;
		}
		return 0;
	}

	/* A new USB device is ready at this point */
	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);

	usb_hub_port_connect_change(dev, i);

	if (portchange & USB_PORT_STAT_C_ENABLE) {
		debug("port %d enable change, status %x\n", i + 1, portstatus);
		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
		/*
		 * The following hack causes a ghost device problem
		 * to Faraday EHCI
		 */
#ifndef CONFIG_USB_EHCI_FARADAY
		/*
		 * EM interference sometimes causes bad shielded USB
		 * devices to be shutdown by the hub, this hack enables
		 * them again. Works at least with mouse driver
		 */
		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
		    (portstatus & USB_PORT_STAT_CONNECTION) &&
		    usb_device_has_child_on_port(dev, i)) {
			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
			      i + 1);
			usb_hub_port_connect_change(dev, i);
		}
#endif
	}

	if (portstatus & USB_PORT_STAT_SUSPEND) {
		debug("port %d suspend change\n", i + 1);
		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
	}

	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
		debug("port %d over-current change\n", i + 1);
		usb_clear_port_feature(dev, i + 1,
				       USB_PORT_FEAT_C_OVER_CURRENT);
		/* Only power-on this one port */
		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
		hub->overcurrent_count[i]++;

		/*
		 * If the max-scan-count is not reached, return without removing
		 * the device from scan-list. This will re-issue a new scan.
		 */
		if (hub->overcurrent_count[i] <=
		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
			return 0;

		/* Otherwise the device will get removed */
		printf("Port %d over-current occurred %d times\n", i + 1,
		       hub->overcurrent_count[i]);
	}

	if (portchange & USB_PORT_STAT_C_RESET) {
		debug("port %d reset change\n", i + 1);
		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
	}

	/*
	 * We're done with this device, so let's remove this device from
	 * scanning list
	 */
	list_del(&usb_scan->list);
	free(usb_scan);

	return 0;
}

static int usb_device_list_scan(void)
{
	struct usb_device_scan *usb_scan;
	struct usb_device_scan *tmp;
	static int running;
	int ret = 0;

	/* Only run this loop once for each controller */
	if (running)
		return 0;

	running = 1;

	while (1) {
		/* We're done, once the list is empty again */
		if (list_empty(&usb_scan_list))
			goto out;

		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
			int ret;

			/* Scan this port */
			ret = usb_scan_port(usb_scan);
			if (ret)
				goto out;
		}
	}

out:
	/*
	 * This USB controller has finished scanning all its connected
	 * USB devices. Set "running" back to 0, so that other USB controllers
	 * will scan their devices too.
	 */
	running = 0;

	return ret;
}

static int usb_hub_configure(struct usb_device *dev)
{
	int i, length;
	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
	unsigned char *bitmap;
	short hubCharacteristics;
	struct usb_hub_descriptor *descriptor;
	struct usb_hub_device *hub;
	__maybe_unused struct usb_hub_status *hubsts;
	int ret;

	/* "allocate" Hub device */
	hub = usb_hub_allocate();
	if (hub == NULL)
		return -ENOMEM;
	hub->pusb_dev = dev;
	/* Get the the hub descriptor */
	ret = usb_get_hub_descriptor(dev, buffer, 4);
	if (ret < 0) {
		debug("usb_hub_configure: failed to get hub " \
		      "descriptor, giving up %lX\n", dev->status);
		return ret;
	}
	descriptor = (struct usb_hub_descriptor *)buffer;

	length = min_t(int, descriptor->bLength,
		       sizeof(struct usb_hub_descriptor));

	ret = usb_get_hub_descriptor(dev, buffer, length);
	if (ret < 0) {
		debug("usb_hub_configure: failed to get hub " \
		      "descriptor 2nd giving up %lX\n", dev->status);
		return ret;
	}
	memcpy((unsigned char *)&hub->desc, buffer, length);
	/* adjust 16bit values */
	put_unaligned(le16_to_cpu(get_unaligned(
			&descriptor->wHubCharacteristics)),
			&hub->desc.wHubCharacteristics);
	/* set the bitmap */
	bitmap = (unsigned char *)&hub->desc.DeviceRemovable[0];
	/* devices not removable by default */
	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
	bitmap = (unsigned char *)&hub->desc.PortPowerCtrlMask[0];
	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */

	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
		hub->desc.DeviceRemovable[i] = descriptor->DeviceRemovable[i];

	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
		hub->desc.PortPowerCtrlMask[i] = descriptor->PortPowerCtrlMask[i];

	dev->maxchild = descriptor->bNbrPorts;
	debug("%d ports detected\n", dev->maxchild);

	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
	switch (hubCharacteristics & HUB_CHAR_LPSM) {
	case 0x00:
		debug("ganged power switching\n");
		break;
	case 0x01:
		debug("individual port power switching\n");
		break;
	case 0x02:
	case 0x03:
		debug("unknown reserved power switching mode\n");
		break;
	}

	if (hubCharacteristics & HUB_CHAR_COMPOUND)
		debug("part of a compound device\n");
	else
		debug("standalone hub\n");

	switch (hubCharacteristics & HUB_CHAR_OCPM) {
	case 0x00:
		debug("global over-current protection\n");
		break;
	case 0x08:
		debug("individual port over-current protection\n");
		break;
	case 0x10:
	case 0x18:
		debug("no over-current protection\n");
		break;
	}

	debug("power on to power good time: %dms\n",
	      descriptor->bPwrOn2PwrGood * 2);
	debug("hub controller current requirement: %dmA\n",
	      descriptor->bHubContrCurrent);

	for (i = 0; i < dev->maxchild; i++)
		debug("port %d is%s removable\n", i + 1,
		      hub->desc.DeviceRemovable[(i + 1) / 8] & \
		      (1 << ((i + 1) % 8)) ? " not" : "");

	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
		debug("usb_hub_configure: failed to get Status - " \
		      "too long: %d\n", descriptor->bLength);
		return -EFBIG;
	}

	ret = usb_get_hub_status(dev, buffer);
	if (ret < 0) {
		debug("usb_hub_configure: failed to get Status %lX\n",
		      dev->status);
		return ret;
	}

#ifdef DEBUG
	hubsts = (struct usb_hub_status *)buffer;
#endif

	debug("get_hub_status returned status %X, change %X\n",
	      le16_to_cpu(hubsts->wHubStatus),
	      le16_to_cpu(hubsts->wHubChange));
	debug("local power source is %s\n",
	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
	      "lost (inactive)" : "good");
	debug("%sover-current condition exists\n",
	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
	      "" : "no ");
	usb_hub_power_on(hub);

	/*
	 * Reset any devices that may be in a bad state when applying
	 * the power.  This is a __weak function.  Resetting of the devices
	 * should occur in the board file of the device.
	 */
	for (i = 0; i < dev->maxchild; i++)
		usb_hub_reset_devices(i + 1);

	/*
	 * Only add the connected USB devices, including potential hubs,
	 * to a scanning list. This list will get scanned and devices that
	 * are detected (either via port connected or via port timeout)
	 * will get removed from this list. Scanning of the devices on this
	 * list will continue until all devices are removed.
	 */
	for (i = 0; i < dev->maxchild; i++) {
		struct usb_device_scan *usb_scan;

		usb_scan = calloc(1, sizeof(*usb_scan));
		if (!usb_scan) {
			printf("Can't allocate memory for USB device!\n");
			return -ENOMEM;
		}
		usb_scan->dev = dev;
		usb_scan->hub = hub;
		usb_scan->port = i;
		list_add_tail(&usb_scan->list, &usb_scan_list);
	}

	/*
	 * And now call the scanning code which loops over the generated list
	 */
	ret = usb_device_list_scan();

	return ret;
}

static int usb_hub_check(struct usb_device *dev, int ifnum)
{
	struct usb_interface *iface;
	struct usb_endpoint_descriptor *ep = NULL;

	iface = &dev->config.if_desc[ifnum];
	/* Is it a hub? */
	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
		goto err;
	/* Some hubs have a subclass of 1, which AFAICT according to the */
	/*  specs is not defined, but it works */
	if ((iface->desc.bInterfaceSubClass != 0) &&
	    (iface->desc.bInterfaceSubClass != 1))
		goto err;
	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
	if (iface->desc.bNumEndpoints != 1)
		goto err;
	ep = &iface->ep_desc[0];
	/* Output endpoint? Curiousier and curiousier.. */
	if (!(ep->bEndpointAddress & USB_DIR_IN))
		goto err;
	/* If it's not an interrupt endpoint, we'd better punt! */
	if ((ep->bmAttributes & 3) != 3)
		goto err;
	/* We found a hub */
	debug("USB hub found\n");
	return 0;

err:
	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
	      iface->desc.bNumEndpoints);
	if (ep) {
		debug("   bEndpointAddress=%#x, bmAttributes=%d",
		      ep->bEndpointAddress, ep->bmAttributes);
	}

	return -ENOENT;
}

int usb_hub_probe(struct usb_device *dev, int ifnum)
{
	int ret;

	ret = usb_hub_check(dev, ifnum);
	if (ret)
		return 0;
	ret = usb_hub_configure(dev);
	return ret;
}

#ifdef CONFIG_DM_USB
int usb_hub_scan(struct udevice *hub)
{
	struct usb_device *udev = dev_get_parent_priv(hub);

	return usb_hub_configure(udev);
}

static int usb_hub_post_probe(struct udevice *dev)
{
	debug("%s\n", __func__);
	return usb_hub_scan(dev);
}

static const struct udevice_id usb_hub_ids[] = {
	{ .compatible = "usb-hub" },
	{ }
};

U_BOOT_DRIVER(usb_generic_hub) = {
	.name	= "usb_hub",
	.id	= UCLASS_USB_HUB,
	.of_match = usb_hub_ids,
	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
};

UCLASS_DRIVER(usb_hub) = {
	.id		= UCLASS_USB_HUB,
	.name		= "usb_hub",
	.post_bind	= dm_scan_fdt_dev,
	.post_probe	= usb_hub_post_probe,
	.child_pre_probe	= usb_child_pre_probe,
	.per_child_auto_alloc_size = sizeof(struct usb_device),
	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
};

static const struct usb_device_id hub_id_table[] = {
	{
		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
		.bDeviceClass = USB_CLASS_HUB
	},
	{ }	/* Terminating entry */
};

U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);

#endif