xref: /openbmc/u-boot/common/usb_hub.c (revision ea743e65)
1 /*
2  * Most of this source has been derived from the Linux USB
3  * project:
4  * (C) Copyright Linus Torvalds 1999
5  * (C) Copyright Johannes Erdfelt 1999-2001
6  * (C) Copyright Andreas Gal 1999
7  * (C) Copyright Gregory P. Smith 1999
8  * (C) Copyright Deti Fliegl 1999 (new USB architecture)
9  * (C) Copyright Randy Dunlap 2000
10  * (C) Copyright David Brownell 2000 (kernel hotplug, usb_device_id)
11  * (C) Copyright Yggdrasil Computing, Inc. 2000
12  *     (usb_device_id matching changes by Adam J. Richter)
13  *
14  * Adapted for U-Boot:
15  * (C) Copyright 2001 Denis Peter, MPL AG Switzerland
16  *
17  * SPDX-License-Identifier:	GPL-2.0+
18  */
19 
20 /****************************************************************************
21  * HUB "Driver"
22  * Probes device for being a hub and configurate it
23  */
24 
25 #include <common.h>
26 #include <command.h>
27 #include <dm.h>
28 #include <errno.h>
29 #include <memalign.h>
30 #include <asm/processor.h>
31 #include <asm/unaligned.h>
32 #include <linux/ctype.h>
33 #include <linux/list.h>
34 #include <asm/byteorder.h>
35 #ifdef CONFIG_SANDBOX
36 #include <asm/state.h>
37 #endif
38 #include <asm/unaligned.h>
39 #include <dm/root.h>
40 
41 DECLARE_GLOBAL_DATA_PTR;
42 
43 #include <usb.h>
44 #ifdef CONFIG_4xx
45 #include <asm/4xx_pci.h>
46 #endif
47 
48 #define USB_BUFSIZ	512
49 
50 #define HUB_SHORT_RESET_TIME	20
51 #define HUB_LONG_RESET_TIME	200
52 
53 #define PORT_OVERCURRENT_MAX_SCAN_COUNT		3
54 
55 struct usb_device_scan {
56 	struct usb_device *dev;		/* USB hub device to scan */
57 	struct usb_hub_device *hub;	/* USB hub struct */
58 	int port;			/* USB port to scan */
59 	struct list_head list;
60 };
61 
62 /* TODO(sjg@chromium.org): Remove this when CONFIG_DM_USB is defined */
63 static struct usb_hub_device hub_dev[USB_MAX_HUB];
64 static int usb_hub_index;
65 static LIST_HEAD(usb_scan_list);
66 
67 __weak void usb_hub_reset_devices(int port)
68 {
69 	return;
70 }
71 
72 static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
73 {
74 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
75 		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
76 		USB_DT_HUB << 8, 0, data, size, USB_CNTL_TIMEOUT);
77 }
78 
79 static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
80 {
81 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
82 				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
83 				port, NULL, 0, USB_CNTL_TIMEOUT);
84 }
85 
86 static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
87 {
88 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
89 				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
90 				port, NULL, 0, USB_CNTL_TIMEOUT);
91 }
92 
93 static int usb_get_hub_status(struct usb_device *dev, void *data)
94 {
95 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
96 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
97 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
98 }
99 
100 int usb_get_port_status(struct usb_device *dev, int port, void *data)
101 {
102 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
103 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
104 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
105 }
106 
107 
108 static void usb_hub_power_on(struct usb_hub_device *hub)
109 {
110 	int i;
111 	struct usb_device *dev;
112 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
113 	const char *env;
114 
115 	dev = hub->pusb_dev;
116 
117 	debug("enabling power on all ports\n");
118 	for (i = 0; i < dev->maxchild; i++) {
119 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
120 		debug("port %d returns %lX\n", i + 1, dev->status);
121 	}
122 
123 #ifdef CONFIG_SANDBOX
124 	/*
125 	 * Don't set timeout / delay values here. This results
126 	 * in these values still being reset to 0.
127 	 */
128 	if (state_get_skip_delays())
129 		return;
130 #endif
131 
132 	/*
133 	 * Wait for power to become stable,
134 	 * plus spec-defined max time for device to connect
135 	 * but allow this time to be increased via env variable as some
136 	 * devices break the spec and require longer warm-up times
137 	 */
138 	env = getenv("usb_pgood_delay");
139 	if (env)
140 		pgood_delay = max(pgood_delay,
141 			          (unsigned)simple_strtol(env, NULL, 0));
142 	debug("pgood_delay=%dms\n", pgood_delay);
143 
144 	/*
145 	 * Do a minimum delay of the larger value of 100ms or pgood_delay
146 	 * so that the power can stablize before the devices are queried
147 	 */
148 	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);
149 
150 	/*
151 	 * Record the power-on timeout here. The max. delay (timeout)
152 	 * will be done based on this value in the USB port loop in
153 	 * usb_hub_configure() later.
154 	 */
155 	hub->connect_timeout = hub->query_delay + 1000;
156 	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
157 	      dev->devnum, max(100, (int)pgood_delay),
158 	      max(100, (int)pgood_delay) + 1000);
159 }
160 
161 void usb_hub_reset(void)
162 {
163 	usb_hub_index = 0;
164 
165 	/* Zero out global hub_dev in case its re-used again */
166 	memset(hub_dev, 0, sizeof(hub_dev));
167 }
168 
169 static struct usb_hub_device *usb_hub_allocate(void)
170 {
171 	if (usb_hub_index < USB_MAX_HUB)
172 		return &hub_dev[usb_hub_index++];
173 
174 	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
175 	return NULL;
176 }
177 
178 #define MAX_TRIES 5
179 
180 static inline char *portspeed(int portstatus)
181 {
182 	char *speed_str;
183 
184 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
185 	case USB_PORT_STAT_SUPER_SPEED:
186 		speed_str = "5 Gb/s";
187 		break;
188 	case USB_PORT_STAT_HIGH_SPEED:
189 		speed_str = "480 Mb/s";
190 		break;
191 	case USB_PORT_STAT_LOW_SPEED:
192 		speed_str = "1.5 Mb/s";
193 		break;
194 	default:
195 		speed_str = "12 Mb/s";
196 		break;
197 	}
198 
199 	return speed_str;
200 }
201 
202 int legacy_hub_port_reset(struct usb_device *dev, int port,
203 			unsigned short *portstat)
204 {
205 	int err, tries;
206 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
207 	unsigned short portstatus, portchange;
208 	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
209 
210 #ifdef CONFIG_DM_USB
211 	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
212 	      port + 1);
213 #else
214 	debug("%s: resetting port %d...\n", __func__, port + 1);
215 #endif
216 	for (tries = 0; tries < MAX_TRIES; tries++) {
217 		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
218 		if (err < 0)
219 			return err;
220 
221 		mdelay(delay);
222 
223 		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
224 			debug("get_port_status failed status %lX\n",
225 			      dev->status);
226 			return -1;
227 		}
228 		portstatus = le16_to_cpu(portsts->wPortStatus);
229 		portchange = le16_to_cpu(portsts->wPortChange);
230 
231 		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
232 							portspeed(portstatus));
233 
234 		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
235 		      "  USB_PORT_STAT_ENABLE %d\n",
236 		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
237 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
238 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
239 
240 		/*
241 		 * Perhaps we should check for the following here:
242 		 * - C_CONNECTION hasn't been set.
243 		 * - CONNECTION is still set.
244 		 *
245 		 * Doing so would ensure that the device is still connected
246 		 * to the bus, and hasn't been unplugged or replaced while the
247 		 * USB bus reset was going on.
248 		 *
249 		 * However, if we do that, then (at least) a San Disk Ultra
250 		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
251 		 * Tegra Jetson TK1 board. For some reason, the device appears
252 		 * to briefly drop off the bus when this second bus reset is
253 		 * executed, yet if we retry this loop, it'll eventually come
254 		 * back after another reset or two.
255 		 */
256 
257 		if (portstatus & USB_PORT_STAT_ENABLE)
258 			break;
259 
260 		/* Switch to long reset delay for the next round */
261 		delay = HUB_LONG_RESET_TIME;
262 	}
263 
264 	if (tries == MAX_TRIES) {
265 		debug("Cannot enable port %i after %i retries, " \
266 		      "disabling port.\n", port + 1, MAX_TRIES);
267 		debug("Maybe the USB cable is bad?\n");
268 		return -1;
269 	}
270 
271 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
272 	*portstat = portstatus;
273 	return 0;
274 }
275 
276 #ifdef CONFIG_DM_USB
277 int hub_port_reset(struct udevice *dev, int port, unsigned short *portstat)
278 {
279 	struct usb_device *udev = dev_get_parent_priv(dev);
280 
281 	return legacy_hub_port_reset(udev, port, portstat);
282 }
283 #endif
284 
285 int usb_hub_port_connect_change(struct usb_device *dev, int port)
286 {
287 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
288 	unsigned short portstatus;
289 	int ret, speed;
290 
291 	/* Check status */
292 	ret = usb_get_port_status(dev, port + 1, portsts);
293 	if (ret < 0) {
294 		debug("get_port_status failed\n");
295 		return ret;
296 	}
297 
298 	portstatus = le16_to_cpu(portsts->wPortStatus);
299 	debug("portstatus %x, change %x, %s\n",
300 	      portstatus,
301 	      le16_to_cpu(portsts->wPortChange),
302 	      portspeed(portstatus));
303 
304 	/* Clear the connection change status */
305 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);
306 
307 	/* Disconnect any existing devices under this port */
308 	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
309 	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
310 	    usb_device_has_child_on_port(dev, port)) {
311 		debug("usb_disconnect(&hub->children[port]);\n");
312 		/* Return now if nothing is connected */
313 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
314 			return -ENOTCONN;
315 	}
316 
317 	/* Reset the port */
318 	ret = legacy_hub_port_reset(dev, port, &portstatus);
319 	if (ret < 0) {
320 		if (ret != -ENXIO)
321 			printf("cannot reset port %i!?\n", port + 1);
322 		return ret;
323 	}
324 
325 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
326 	case USB_PORT_STAT_SUPER_SPEED:
327 		speed = USB_SPEED_SUPER;
328 		break;
329 	case USB_PORT_STAT_HIGH_SPEED:
330 		speed = USB_SPEED_HIGH;
331 		break;
332 	case USB_PORT_STAT_LOW_SPEED:
333 		speed = USB_SPEED_LOW;
334 		break;
335 	default:
336 		speed = USB_SPEED_FULL;
337 		break;
338 	}
339 
340 #ifdef CONFIG_DM_USB
341 	struct udevice *child;
342 
343 	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
344 #else
345 	struct usb_device *usb;
346 
347 	ret = usb_alloc_new_device(dev->controller, &usb);
348 	if (ret) {
349 		printf("cannot create new device: ret=%d", ret);
350 		return ret;
351 	}
352 
353 	dev->children[port] = usb;
354 	usb->speed = speed;
355 	usb->parent = dev;
356 	usb->portnr = port + 1;
357 	/* Run it through the hoops (find a driver, etc) */
358 	ret = usb_new_device(usb);
359 	if (ret < 0) {
360 		/* Woops, disable the port */
361 		usb_free_device(dev->controller);
362 		dev->children[port] = NULL;
363 	}
364 #endif
365 	if (ret < 0) {
366 		debug("hub: disabling port %d\n", port + 1);
367 		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
368 	}
369 
370 	return ret;
371 }
372 
373 static int usb_scan_port(struct usb_device_scan *usb_scan)
374 {
375 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
376 	unsigned short portstatus;
377 	unsigned short portchange;
378 	struct usb_device *dev;
379 	struct usb_hub_device *hub;
380 	int ret = 0;
381 	int i;
382 
383 	dev = usb_scan->dev;
384 	hub = usb_scan->hub;
385 	i = usb_scan->port;
386 
387 	/*
388 	 * Don't talk to the device before the query delay is expired.
389 	 * This is needed for voltages to stabalize.
390 	 */
391 	if (get_timer(0) < hub->query_delay)
392 		return 0;
393 
394 	ret = usb_get_port_status(dev, i + 1, portsts);
395 	if (ret < 0) {
396 		debug("get_port_status failed\n");
397 		if (get_timer(0) >= hub->connect_timeout) {
398 			debug("devnum=%d port=%d: timeout\n",
399 			      dev->devnum, i + 1);
400 			/* Remove this device from scanning list */
401 			list_del(&usb_scan->list);
402 			free(usb_scan);
403 			return 0;
404 		}
405 		return 0;
406 	}
407 
408 	portstatus = le16_to_cpu(portsts->wPortStatus);
409 	portchange = le16_to_cpu(portsts->wPortChange);
410 	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
411 
412 	/* No connection change happened, wait a bit more. */
413 	if (!(portchange & USB_PORT_STAT_C_CONNECTION)) {
414 		if (get_timer(0) >= hub->connect_timeout) {
415 			debug("devnum=%d port=%d: timeout\n",
416 			      dev->devnum, i + 1);
417 			/* Remove this device from scanning list */
418 			list_del(&usb_scan->list);
419 			free(usb_scan);
420 			return 0;
421 		}
422 		return 0;
423 	}
424 
425 	/* Test if the connection came up, and if not exit */
426 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
427 		return 0;
428 
429 	/* A new USB device is ready at this point */
430 	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);
431 
432 	usb_hub_port_connect_change(dev, i);
433 
434 	if (portchange & USB_PORT_STAT_C_ENABLE) {
435 		debug("port %d enable change, status %x\n", i + 1, portstatus);
436 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
437 		/*
438 		 * The following hack causes a ghost device problem
439 		 * to Faraday EHCI
440 		 */
441 #ifndef CONFIG_USB_EHCI_FARADAY
442 		/*
443 		 * EM interference sometimes causes bad shielded USB
444 		 * devices to be shutdown by the hub, this hack enables
445 		 * them again. Works at least with mouse driver
446 		 */
447 		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
448 		    (portstatus & USB_PORT_STAT_CONNECTION) &&
449 		    usb_device_has_child_on_port(dev, i)) {
450 			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
451 			      i + 1);
452 			usb_hub_port_connect_change(dev, i);
453 		}
454 #endif
455 	}
456 
457 	if (portstatus & USB_PORT_STAT_SUSPEND) {
458 		debug("port %d suspend change\n", i + 1);
459 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
460 	}
461 
462 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
463 		debug("port %d over-current change\n", i + 1);
464 		usb_clear_port_feature(dev, i + 1,
465 				       USB_PORT_FEAT_C_OVER_CURRENT);
466 		/* Only power-on this one port */
467 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
468 		hub->overcurrent_count[i]++;
469 
470 		/*
471 		 * If the max-scan-count is not reached, return without removing
472 		 * the device from scan-list. This will re-issue a new scan.
473 		 */
474 		if (hub->overcurrent_count[i] <=
475 		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
476 			return 0;
477 
478 		/* Otherwise the device will get removed */
479 		printf("Port %d over-current occurred %d times\n", i + 1,
480 		       hub->overcurrent_count[i]);
481 	}
482 
483 	if (portchange & USB_PORT_STAT_C_RESET) {
484 		debug("port %d reset change\n", i + 1);
485 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
486 	}
487 
488 	/*
489 	 * We're done with this device, so let's remove this device from
490 	 * scanning list
491 	 */
492 	list_del(&usb_scan->list);
493 	free(usb_scan);
494 
495 	return 0;
496 }
497 
498 static int usb_device_list_scan(void)
499 {
500 	struct usb_device_scan *usb_scan;
501 	struct usb_device_scan *tmp;
502 	static int running;
503 	int ret = 0;
504 
505 	/* Only run this loop once for each controller */
506 	if (running)
507 		return 0;
508 
509 	running = 1;
510 
511 	while (1) {
512 		/* We're done, once the list is empty again */
513 		if (list_empty(&usb_scan_list))
514 			goto out;
515 
516 		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
517 			int ret;
518 
519 			/* Scan this port */
520 			ret = usb_scan_port(usb_scan);
521 			if (ret)
522 				goto out;
523 		}
524 	}
525 
526 out:
527 	/*
528 	 * This USB controller has finished scanning all its connected
529 	 * USB devices. Set "running" back to 0, so that other USB controllers
530 	 * will scan their devices too.
531 	 */
532 	running = 0;
533 
534 	return ret;
535 }
536 
537 static int usb_hub_configure(struct usb_device *dev)
538 {
539 	int i, length;
540 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
541 	unsigned char *bitmap;
542 	short hubCharacteristics;
543 	struct usb_hub_descriptor *descriptor;
544 	struct usb_hub_device *hub;
545 	__maybe_unused struct usb_hub_status *hubsts;
546 	int ret;
547 
548 	/* "allocate" Hub device */
549 	hub = usb_hub_allocate();
550 	if (hub == NULL)
551 		return -ENOMEM;
552 	hub->pusb_dev = dev;
553 	/* Get the the hub descriptor */
554 	ret = usb_get_hub_descriptor(dev, buffer, 4);
555 	if (ret < 0) {
556 		debug("usb_hub_configure: failed to get hub " \
557 		      "descriptor, giving up %lX\n", dev->status);
558 		return ret;
559 	}
560 	descriptor = (struct usb_hub_descriptor *)buffer;
561 
562 	length = min_t(int, descriptor->bLength,
563 		       sizeof(struct usb_hub_descriptor));
564 
565 	ret = usb_get_hub_descriptor(dev, buffer, length);
566 	if (ret < 0) {
567 		debug("usb_hub_configure: failed to get hub " \
568 		      "descriptor 2nd giving up %lX\n", dev->status);
569 		return ret;
570 	}
571 	memcpy((unsigned char *)&hub->desc, buffer, length);
572 	/* adjust 16bit values */
573 	put_unaligned(le16_to_cpu(get_unaligned(
574 			&descriptor->wHubCharacteristics)),
575 			&hub->desc.wHubCharacteristics);
576 	/* set the bitmap */
577 	bitmap = (unsigned char *)&hub->desc.DeviceRemovable[0];
578 	/* devices not removable by default */
579 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
580 	bitmap = (unsigned char *)&hub->desc.PortPowerCtrlMask[0];
581 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */
582 
583 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
584 		hub->desc.DeviceRemovable[i] = descriptor->DeviceRemovable[i];
585 
586 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
587 		hub->desc.PortPowerCtrlMask[i] = descriptor->PortPowerCtrlMask[i];
588 
589 	dev->maxchild = descriptor->bNbrPorts;
590 	debug("%d ports detected\n", dev->maxchild);
591 
592 	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
593 	switch (hubCharacteristics & HUB_CHAR_LPSM) {
594 	case 0x00:
595 		debug("ganged power switching\n");
596 		break;
597 	case 0x01:
598 		debug("individual port power switching\n");
599 		break;
600 	case 0x02:
601 	case 0x03:
602 		debug("unknown reserved power switching mode\n");
603 		break;
604 	}
605 
606 	if (hubCharacteristics & HUB_CHAR_COMPOUND)
607 		debug("part of a compound device\n");
608 	else
609 		debug("standalone hub\n");
610 
611 	switch (hubCharacteristics & HUB_CHAR_OCPM) {
612 	case 0x00:
613 		debug("global over-current protection\n");
614 		break;
615 	case 0x08:
616 		debug("individual port over-current protection\n");
617 		break;
618 	case 0x10:
619 	case 0x18:
620 		debug("no over-current protection\n");
621 		break;
622 	}
623 
624 	debug("power on to power good time: %dms\n",
625 	      descriptor->bPwrOn2PwrGood * 2);
626 	debug("hub controller current requirement: %dmA\n",
627 	      descriptor->bHubContrCurrent);
628 
629 	for (i = 0; i < dev->maxchild; i++)
630 		debug("port %d is%s removable\n", i + 1,
631 		      hub->desc.DeviceRemovable[(i + 1) / 8] & \
632 		      (1 << ((i + 1) % 8)) ? " not" : "");
633 
634 	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
635 		debug("usb_hub_configure: failed to get Status - " \
636 		      "too long: %d\n", descriptor->bLength);
637 		return -EFBIG;
638 	}
639 
640 	ret = usb_get_hub_status(dev, buffer);
641 	if (ret < 0) {
642 		debug("usb_hub_configure: failed to get Status %lX\n",
643 		      dev->status);
644 		return ret;
645 	}
646 
647 #ifdef DEBUG
648 	hubsts = (struct usb_hub_status *)buffer;
649 #endif
650 
651 	debug("get_hub_status returned status %X, change %X\n",
652 	      le16_to_cpu(hubsts->wHubStatus),
653 	      le16_to_cpu(hubsts->wHubChange));
654 	debug("local power source is %s\n",
655 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
656 	      "lost (inactive)" : "good");
657 	debug("%sover-current condition exists\n",
658 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
659 	      "" : "no ");
660 	usb_hub_power_on(hub);
661 
662 	/*
663 	 * Reset any devices that may be in a bad state when applying
664 	 * the power.  This is a __weak function.  Resetting of the devices
665 	 * should occur in the board file of the device.
666 	 */
667 	for (i = 0; i < dev->maxchild; i++)
668 		usb_hub_reset_devices(i + 1);
669 
670 	/*
671 	 * Only add the connected USB devices, including potential hubs,
672 	 * to a scanning list. This list will get scanned and devices that
673 	 * are detected (either via port connected or via port timeout)
674 	 * will get removed from this list. Scanning of the devices on this
675 	 * list will continue until all devices are removed.
676 	 */
677 	for (i = 0; i < dev->maxchild; i++) {
678 		struct usb_device_scan *usb_scan;
679 
680 		usb_scan = calloc(1, sizeof(*usb_scan));
681 		if (!usb_scan) {
682 			printf("Can't allocate memory for USB device!\n");
683 			return -ENOMEM;
684 		}
685 		usb_scan->dev = dev;
686 		usb_scan->hub = hub;
687 		usb_scan->port = i;
688 		list_add_tail(&usb_scan->list, &usb_scan_list);
689 	}
690 
691 	/*
692 	 * And now call the scanning code which loops over the generated list
693 	 */
694 	ret = usb_device_list_scan();
695 
696 	return ret;
697 }
698 
699 static int usb_hub_check(struct usb_device *dev, int ifnum)
700 {
701 	struct usb_interface *iface;
702 	struct usb_endpoint_descriptor *ep = NULL;
703 
704 	iface = &dev->config.if_desc[ifnum];
705 	/* Is it a hub? */
706 	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
707 		goto err;
708 	/* Some hubs have a subclass of 1, which AFAICT according to the */
709 	/*  specs is not defined, but it works */
710 	if ((iface->desc.bInterfaceSubClass != 0) &&
711 	    (iface->desc.bInterfaceSubClass != 1))
712 		goto err;
713 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
714 	if (iface->desc.bNumEndpoints != 1)
715 		goto err;
716 	ep = &iface->ep_desc[0];
717 	/* Output endpoint? Curiousier and curiousier.. */
718 	if (!(ep->bEndpointAddress & USB_DIR_IN))
719 		goto err;
720 	/* If it's not an interrupt endpoint, we'd better punt! */
721 	if ((ep->bmAttributes & 3) != 3)
722 		goto err;
723 	/* We found a hub */
724 	debug("USB hub found\n");
725 	return 0;
726 
727 err:
728 	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
729 	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
730 	      iface->desc.bNumEndpoints);
731 	if (ep) {
732 		debug("   bEndpointAddress=%#x, bmAttributes=%d",
733 		      ep->bEndpointAddress, ep->bmAttributes);
734 	}
735 
736 	return -ENOENT;
737 }
738 
739 int usb_hub_probe(struct usb_device *dev, int ifnum)
740 {
741 	int ret;
742 
743 	ret = usb_hub_check(dev, ifnum);
744 	if (ret)
745 		return 0;
746 	ret = usb_hub_configure(dev);
747 	return ret;
748 }
749 
750 #ifdef CONFIG_DM_USB
751 int usb_hub_scan(struct udevice *hub)
752 {
753 	struct usb_device *udev = dev_get_parent_priv(hub);
754 
755 	return usb_hub_configure(udev);
756 }
757 
758 static int usb_hub_post_bind(struct udevice *dev)
759 {
760 	/* Scan the bus for devices */
761 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
762 }
763 
764 static int usb_hub_post_probe(struct udevice *dev)
765 {
766 	debug("%s\n", __func__);
767 	return usb_hub_scan(dev);
768 }
769 
770 static const struct udevice_id usb_hub_ids[] = {
771 	{ .compatible = "usb-hub" },
772 	{ }
773 };
774 
775 U_BOOT_DRIVER(usb_generic_hub) = {
776 	.name	= "usb_hub",
777 	.id	= UCLASS_USB_HUB,
778 	.of_match = usb_hub_ids,
779 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
780 };
781 
782 UCLASS_DRIVER(usb_hub) = {
783 	.id		= UCLASS_USB_HUB,
784 	.name		= "usb_hub",
785 	.post_bind	= usb_hub_post_bind,
786 	.post_probe	= usb_hub_post_probe,
787 	.child_pre_probe	= usb_child_pre_probe,
788 	.per_child_auto_alloc_size = sizeof(struct usb_device),
789 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
790 };
791 
792 static const struct usb_device_id hub_id_table[] = {
793 	{
794 		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
795 		.bDeviceClass = USB_CLASS_HUB
796 	},
797 	{ }	/* Terminating entry */
798 };
799 
800 U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);
801 
802 #endif
803