xref: /openbmc/u-boot/common/usb_hub.c (revision d7c11502)
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 
40 DECLARE_GLOBAL_DATA_PTR;
41 
42 #include <usb.h>
43 
44 #define USB_BUFSIZ	512
45 
46 #define HUB_SHORT_RESET_TIME	20
47 #define HUB_LONG_RESET_TIME	200
48 
49 #define PORT_OVERCURRENT_MAX_SCAN_COUNT		3
50 
51 struct usb_device_scan {
52 	struct usb_device *dev;		/* USB hub device to scan */
53 	struct usb_hub_device *hub;	/* USB hub struct */
54 	int port;			/* USB port to scan */
55 	struct list_head list;
56 };
57 
58 /* TODO(sjg@chromium.org): Remove this when CONFIG_DM_USB is defined */
59 static struct usb_hub_device hub_dev[USB_MAX_HUB];
60 static int usb_hub_index;
61 static LIST_HEAD(usb_scan_list);
62 
63 __weak void usb_hub_reset_devices(int port)
64 {
65 	return;
66 }
67 
68 static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
69 {
70 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
71 		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
72 		USB_DT_HUB << 8, 0, data, size, USB_CNTL_TIMEOUT);
73 }
74 
75 static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
76 {
77 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
78 				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
79 				port, NULL, 0, USB_CNTL_TIMEOUT);
80 }
81 
82 static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
83 {
84 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
85 				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
86 				port, NULL, 0, USB_CNTL_TIMEOUT);
87 }
88 
89 static int usb_get_hub_status(struct usb_device *dev, void *data)
90 {
91 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
92 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
93 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
94 }
95 
96 int usb_get_port_status(struct usb_device *dev, int port, void *data)
97 {
98 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
99 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
100 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
101 }
102 
103 
104 static void usb_hub_power_on(struct usb_hub_device *hub)
105 {
106 	int i;
107 	struct usb_device *dev;
108 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
109 	const char *env;
110 
111 	dev = hub->pusb_dev;
112 
113 	debug("enabling power on all ports\n");
114 	for (i = 0; i < dev->maxchild; i++) {
115 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
116 		debug("port %d returns %lX\n", i + 1, dev->status);
117 	}
118 
119 #ifdef CONFIG_SANDBOX
120 	/*
121 	 * Don't set timeout / delay values here. This results
122 	 * in these values still being reset to 0.
123 	 */
124 	if (state_get_skip_delays())
125 		return;
126 #endif
127 
128 	/*
129 	 * Wait for power to become stable,
130 	 * plus spec-defined max time for device to connect
131 	 * but allow this time to be increased via env variable as some
132 	 * devices break the spec and require longer warm-up times
133 	 */
134 	env = getenv("usb_pgood_delay");
135 	if (env)
136 		pgood_delay = max(pgood_delay,
137 			          (unsigned)simple_strtol(env, NULL, 0));
138 	debug("pgood_delay=%dms\n", pgood_delay);
139 
140 	/*
141 	 * Do a minimum delay of the larger value of 100ms or pgood_delay
142 	 * so that the power can stablize before the devices are queried
143 	 */
144 	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);
145 
146 	/*
147 	 * Record the power-on timeout here. The max. delay (timeout)
148 	 * will be done based on this value in the USB port loop in
149 	 * usb_hub_configure() later.
150 	 */
151 	hub->connect_timeout = hub->query_delay + 1000;
152 	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
153 	      dev->devnum, max(100, (int)pgood_delay),
154 	      max(100, (int)pgood_delay) + 1000);
155 }
156 
157 void usb_hub_reset(void)
158 {
159 	usb_hub_index = 0;
160 
161 	/* Zero out global hub_dev in case its re-used again */
162 	memset(hub_dev, 0, sizeof(hub_dev));
163 }
164 
165 static struct usb_hub_device *usb_hub_allocate(void)
166 {
167 	if (usb_hub_index < USB_MAX_HUB)
168 		return &hub_dev[usb_hub_index++];
169 
170 	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
171 	return NULL;
172 }
173 
174 #define MAX_TRIES 5
175 
176 static inline char *portspeed(int portstatus)
177 {
178 	char *speed_str;
179 
180 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
181 	case USB_PORT_STAT_SUPER_SPEED:
182 		speed_str = "5 Gb/s";
183 		break;
184 	case USB_PORT_STAT_HIGH_SPEED:
185 		speed_str = "480 Mb/s";
186 		break;
187 	case USB_PORT_STAT_LOW_SPEED:
188 		speed_str = "1.5 Mb/s";
189 		break;
190 	default:
191 		speed_str = "12 Mb/s";
192 		break;
193 	}
194 
195 	return speed_str;
196 }
197 
198 int legacy_hub_port_reset(struct usb_device *dev, int port,
199 			unsigned short *portstat)
200 {
201 	int err, tries;
202 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
203 	unsigned short portstatus, portchange;
204 	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
205 
206 #ifdef CONFIG_DM_USB
207 	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
208 	      port + 1);
209 #else
210 	debug("%s: resetting port %d...\n", __func__, port + 1);
211 #endif
212 	for (tries = 0; tries < MAX_TRIES; tries++) {
213 		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
214 		if (err < 0)
215 			return err;
216 
217 		mdelay(delay);
218 
219 		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
220 			debug("get_port_status failed status %lX\n",
221 			      dev->status);
222 			return -1;
223 		}
224 		portstatus = le16_to_cpu(portsts->wPortStatus);
225 		portchange = le16_to_cpu(portsts->wPortChange);
226 
227 		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
228 							portspeed(portstatus));
229 
230 		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
231 		      "  USB_PORT_STAT_ENABLE %d\n",
232 		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
233 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
234 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
235 
236 		/*
237 		 * Perhaps we should check for the following here:
238 		 * - C_CONNECTION hasn't been set.
239 		 * - CONNECTION is still set.
240 		 *
241 		 * Doing so would ensure that the device is still connected
242 		 * to the bus, and hasn't been unplugged or replaced while the
243 		 * USB bus reset was going on.
244 		 *
245 		 * However, if we do that, then (at least) a San Disk Ultra
246 		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
247 		 * Tegra Jetson TK1 board. For some reason, the device appears
248 		 * to briefly drop off the bus when this second bus reset is
249 		 * executed, yet if we retry this loop, it'll eventually come
250 		 * back after another reset or two.
251 		 */
252 
253 		if (portstatus & USB_PORT_STAT_ENABLE)
254 			break;
255 
256 		/* Switch to long reset delay for the next round */
257 		delay = HUB_LONG_RESET_TIME;
258 	}
259 
260 	if (tries == MAX_TRIES) {
261 		debug("Cannot enable port %i after %i retries, " \
262 		      "disabling port.\n", port + 1, MAX_TRIES);
263 		debug("Maybe the USB cable is bad?\n");
264 		return -1;
265 	}
266 
267 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
268 	*portstat = portstatus;
269 	return 0;
270 }
271 
272 #ifdef CONFIG_DM_USB
273 int hub_port_reset(struct udevice *dev, int port, unsigned short *portstat)
274 {
275 	struct usb_device *udev = dev_get_parent_priv(dev);
276 
277 	return legacy_hub_port_reset(udev, port, portstat);
278 }
279 #endif
280 
281 int usb_hub_port_connect_change(struct usb_device *dev, int port)
282 {
283 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
284 	unsigned short portstatus;
285 	int ret, speed;
286 
287 	/* Check status */
288 	ret = usb_get_port_status(dev, port + 1, portsts);
289 	if (ret < 0) {
290 		debug("get_port_status failed\n");
291 		return ret;
292 	}
293 
294 	portstatus = le16_to_cpu(portsts->wPortStatus);
295 	debug("portstatus %x, change %x, %s\n",
296 	      portstatus,
297 	      le16_to_cpu(portsts->wPortChange),
298 	      portspeed(portstatus));
299 
300 	/* Clear the connection change status */
301 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);
302 
303 	/* Disconnect any existing devices under this port */
304 	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
305 	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
306 	    usb_device_has_child_on_port(dev, port)) {
307 		debug("usb_disconnect(&hub->children[port]);\n");
308 		/* Return now if nothing is connected */
309 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
310 			return -ENOTCONN;
311 	}
312 
313 	/* Reset the port */
314 	ret = legacy_hub_port_reset(dev, port, &portstatus);
315 	if (ret < 0) {
316 		if (ret != -ENXIO)
317 			printf("cannot reset port %i!?\n", port + 1);
318 		return ret;
319 	}
320 
321 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
322 	case USB_PORT_STAT_SUPER_SPEED:
323 		speed = USB_SPEED_SUPER;
324 		break;
325 	case USB_PORT_STAT_HIGH_SPEED:
326 		speed = USB_SPEED_HIGH;
327 		break;
328 	case USB_PORT_STAT_LOW_SPEED:
329 		speed = USB_SPEED_LOW;
330 		break;
331 	default:
332 		speed = USB_SPEED_FULL;
333 		break;
334 	}
335 
336 #ifdef CONFIG_DM_USB
337 	struct udevice *child;
338 
339 	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
340 #else
341 	struct usb_device *usb;
342 
343 	ret = usb_alloc_new_device(dev->controller, &usb);
344 	if (ret) {
345 		printf("cannot create new device: ret=%d", ret);
346 		return ret;
347 	}
348 
349 	dev->children[port] = usb;
350 	usb->speed = speed;
351 	usb->parent = dev;
352 	usb->portnr = port + 1;
353 	/* Run it through the hoops (find a driver, etc) */
354 	ret = usb_new_device(usb);
355 	if (ret < 0) {
356 		/* Woops, disable the port */
357 		usb_free_device(dev->controller);
358 		dev->children[port] = NULL;
359 	}
360 #endif
361 	if (ret < 0) {
362 		debug("hub: disabling port %d\n", port + 1);
363 		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
364 	}
365 
366 	return ret;
367 }
368 
369 static int usb_scan_port(struct usb_device_scan *usb_scan)
370 {
371 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
372 	unsigned short portstatus;
373 	unsigned short portchange;
374 	struct usb_device *dev;
375 	struct usb_hub_device *hub;
376 	int ret = 0;
377 	int i;
378 
379 	dev = usb_scan->dev;
380 	hub = usb_scan->hub;
381 	i = usb_scan->port;
382 
383 	/*
384 	 * Don't talk to the device before the query delay is expired.
385 	 * This is needed for voltages to stabalize.
386 	 */
387 	if (get_timer(0) < hub->query_delay)
388 		return 0;
389 
390 	ret = usb_get_port_status(dev, i + 1, portsts);
391 	if (ret < 0) {
392 		debug("get_port_status failed\n");
393 		if (get_timer(0) >= hub->connect_timeout) {
394 			debug("devnum=%d port=%d: timeout\n",
395 			      dev->devnum, i + 1);
396 			/* Remove this device from scanning list */
397 			list_del(&usb_scan->list);
398 			free(usb_scan);
399 			return 0;
400 		}
401 		return 0;
402 	}
403 
404 	portstatus = le16_to_cpu(portsts->wPortStatus);
405 	portchange = le16_to_cpu(portsts->wPortChange);
406 	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
407 
408 	/* No connection change happened, wait a bit more. */
409 	if (!(portchange & USB_PORT_STAT_C_CONNECTION)) {
410 		if (get_timer(0) >= hub->connect_timeout) {
411 			debug("devnum=%d port=%d: timeout\n",
412 			      dev->devnum, i + 1);
413 			/* Remove this device from scanning list */
414 			list_del(&usb_scan->list);
415 			free(usb_scan);
416 			return 0;
417 		}
418 		return 0;
419 	}
420 
421 	/* Test if the connection came up, and if not exit */
422 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
423 		return 0;
424 
425 	/* A new USB device is ready at this point */
426 	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);
427 
428 	usb_hub_port_connect_change(dev, i);
429 
430 	if (portchange & USB_PORT_STAT_C_ENABLE) {
431 		debug("port %d enable change, status %x\n", i + 1, portstatus);
432 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
433 		/*
434 		 * The following hack causes a ghost device problem
435 		 * to Faraday EHCI
436 		 */
437 #ifndef CONFIG_USB_EHCI_FARADAY
438 		/*
439 		 * EM interference sometimes causes bad shielded USB
440 		 * devices to be shutdown by the hub, this hack enables
441 		 * them again. Works at least with mouse driver
442 		 */
443 		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
444 		    (portstatus & USB_PORT_STAT_CONNECTION) &&
445 		    usb_device_has_child_on_port(dev, i)) {
446 			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
447 			      i + 1);
448 			usb_hub_port_connect_change(dev, i);
449 		}
450 #endif
451 	}
452 
453 	if (portstatus & USB_PORT_STAT_SUSPEND) {
454 		debug("port %d suspend change\n", i + 1);
455 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
456 	}
457 
458 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
459 		debug("port %d over-current change\n", i + 1);
460 		usb_clear_port_feature(dev, i + 1,
461 				       USB_PORT_FEAT_C_OVER_CURRENT);
462 		/* Only power-on this one port */
463 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
464 		hub->overcurrent_count[i]++;
465 
466 		/*
467 		 * If the max-scan-count is not reached, return without removing
468 		 * the device from scan-list. This will re-issue a new scan.
469 		 */
470 		if (hub->overcurrent_count[i] <=
471 		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
472 			return 0;
473 
474 		/* Otherwise the device will get removed */
475 		printf("Port %d over-current occurred %d times\n", i + 1,
476 		       hub->overcurrent_count[i]);
477 	}
478 
479 	if (portchange & USB_PORT_STAT_C_RESET) {
480 		debug("port %d reset change\n", i + 1);
481 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
482 	}
483 
484 	/*
485 	 * We're done with this device, so let's remove this device from
486 	 * scanning list
487 	 */
488 	list_del(&usb_scan->list);
489 	free(usb_scan);
490 
491 	return 0;
492 }
493 
494 static int usb_device_list_scan(void)
495 {
496 	struct usb_device_scan *usb_scan;
497 	struct usb_device_scan *tmp;
498 	static int running;
499 	int ret = 0;
500 
501 	/* Only run this loop once for each controller */
502 	if (running)
503 		return 0;
504 
505 	running = 1;
506 
507 	while (1) {
508 		/* We're done, once the list is empty again */
509 		if (list_empty(&usb_scan_list))
510 			goto out;
511 
512 		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
513 			int ret;
514 
515 			/* Scan this port */
516 			ret = usb_scan_port(usb_scan);
517 			if (ret)
518 				goto out;
519 		}
520 	}
521 
522 out:
523 	/*
524 	 * This USB controller has finished scanning all its connected
525 	 * USB devices. Set "running" back to 0, so that other USB controllers
526 	 * will scan their devices too.
527 	 */
528 	running = 0;
529 
530 	return ret;
531 }
532 
533 static int usb_hub_configure(struct usb_device *dev)
534 {
535 	int i, length;
536 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
537 	unsigned char *bitmap;
538 	short hubCharacteristics;
539 	struct usb_hub_descriptor *descriptor;
540 	struct usb_hub_device *hub;
541 	__maybe_unused struct usb_hub_status *hubsts;
542 	int ret;
543 
544 	/* "allocate" Hub device */
545 	hub = usb_hub_allocate();
546 	if (hub == NULL)
547 		return -ENOMEM;
548 	hub->pusb_dev = dev;
549 	/* Get the the hub descriptor */
550 	ret = usb_get_hub_descriptor(dev, buffer, 4);
551 	if (ret < 0) {
552 		debug("usb_hub_configure: failed to get hub " \
553 		      "descriptor, giving up %lX\n", dev->status);
554 		return ret;
555 	}
556 	descriptor = (struct usb_hub_descriptor *)buffer;
557 
558 	length = min_t(int, descriptor->bLength,
559 		       sizeof(struct usb_hub_descriptor));
560 
561 	ret = usb_get_hub_descriptor(dev, buffer, length);
562 	if (ret < 0) {
563 		debug("usb_hub_configure: failed to get hub " \
564 		      "descriptor 2nd giving up %lX\n", dev->status);
565 		return ret;
566 	}
567 	memcpy((unsigned char *)&hub->desc, buffer, length);
568 	/* adjust 16bit values */
569 	put_unaligned(le16_to_cpu(get_unaligned(
570 			&descriptor->wHubCharacteristics)),
571 			&hub->desc.wHubCharacteristics);
572 	/* set the bitmap */
573 	bitmap = (unsigned char *)&hub->desc.DeviceRemovable[0];
574 	/* devices not removable by default */
575 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
576 	bitmap = (unsigned char *)&hub->desc.PortPowerCtrlMask[0];
577 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */
578 
579 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
580 		hub->desc.DeviceRemovable[i] = descriptor->DeviceRemovable[i];
581 
582 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
583 		hub->desc.PortPowerCtrlMask[i] = descriptor->PortPowerCtrlMask[i];
584 
585 	dev->maxchild = descriptor->bNbrPorts;
586 	debug("%d ports detected\n", dev->maxchild);
587 
588 	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
589 	switch (hubCharacteristics & HUB_CHAR_LPSM) {
590 	case 0x00:
591 		debug("ganged power switching\n");
592 		break;
593 	case 0x01:
594 		debug("individual port power switching\n");
595 		break;
596 	case 0x02:
597 	case 0x03:
598 		debug("unknown reserved power switching mode\n");
599 		break;
600 	}
601 
602 	if (hubCharacteristics & HUB_CHAR_COMPOUND)
603 		debug("part of a compound device\n");
604 	else
605 		debug("standalone hub\n");
606 
607 	switch (hubCharacteristics & HUB_CHAR_OCPM) {
608 	case 0x00:
609 		debug("global over-current protection\n");
610 		break;
611 	case 0x08:
612 		debug("individual port over-current protection\n");
613 		break;
614 	case 0x10:
615 	case 0x18:
616 		debug("no over-current protection\n");
617 		break;
618 	}
619 
620 	debug("power on to power good time: %dms\n",
621 	      descriptor->bPwrOn2PwrGood * 2);
622 	debug("hub controller current requirement: %dmA\n",
623 	      descriptor->bHubContrCurrent);
624 
625 	for (i = 0; i < dev->maxchild; i++)
626 		debug("port %d is%s removable\n", i + 1,
627 		      hub->desc.DeviceRemovable[(i + 1) / 8] & \
628 		      (1 << ((i + 1) % 8)) ? " not" : "");
629 
630 	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
631 		debug("usb_hub_configure: failed to get Status - " \
632 		      "too long: %d\n", descriptor->bLength);
633 		return -EFBIG;
634 	}
635 
636 	ret = usb_get_hub_status(dev, buffer);
637 	if (ret < 0) {
638 		debug("usb_hub_configure: failed to get Status %lX\n",
639 		      dev->status);
640 		return ret;
641 	}
642 
643 #ifdef DEBUG
644 	hubsts = (struct usb_hub_status *)buffer;
645 #endif
646 
647 	debug("get_hub_status returned status %X, change %X\n",
648 	      le16_to_cpu(hubsts->wHubStatus),
649 	      le16_to_cpu(hubsts->wHubChange));
650 	debug("local power source is %s\n",
651 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
652 	      "lost (inactive)" : "good");
653 	debug("%sover-current condition exists\n",
654 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
655 	      "" : "no ");
656 	usb_hub_power_on(hub);
657 
658 	/*
659 	 * Reset any devices that may be in a bad state when applying
660 	 * the power.  This is a __weak function.  Resetting of the devices
661 	 * should occur in the board file of the device.
662 	 */
663 	for (i = 0; i < dev->maxchild; i++)
664 		usb_hub_reset_devices(i + 1);
665 
666 	/*
667 	 * Only add the connected USB devices, including potential hubs,
668 	 * to a scanning list. This list will get scanned and devices that
669 	 * are detected (either via port connected or via port timeout)
670 	 * will get removed from this list. Scanning of the devices on this
671 	 * list will continue until all devices are removed.
672 	 */
673 	for (i = 0; i < dev->maxchild; i++) {
674 		struct usb_device_scan *usb_scan;
675 
676 		usb_scan = calloc(1, sizeof(*usb_scan));
677 		if (!usb_scan) {
678 			printf("Can't allocate memory for USB device!\n");
679 			return -ENOMEM;
680 		}
681 		usb_scan->dev = dev;
682 		usb_scan->hub = hub;
683 		usb_scan->port = i;
684 		list_add_tail(&usb_scan->list, &usb_scan_list);
685 	}
686 
687 	/*
688 	 * And now call the scanning code which loops over the generated list
689 	 */
690 	ret = usb_device_list_scan();
691 
692 	return ret;
693 }
694 
695 static int usb_hub_check(struct usb_device *dev, int ifnum)
696 {
697 	struct usb_interface *iface;
698 	struct usb_endpoint_descriptor *ep = NULL;
699 
700 	iface = &dev->config.if_desc[ifnum];
701 	/* Is it a hub? */
702 	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
703 		goto err;
704 	/* Some hubs have a subclass of 1, which AFAICT according to the */
705 	/*  specs is not defined, but it works */
706 	if ((iface->desc.bInterfaceSubClass != 0) &&
707 	    (iface->desc.bInterfaceSubClass != 1))
708 		goto err;
709 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
710 	if (iface->desc.bNumEndpoints != 1)
711 		goto err;
712 	ep = &iface->ep_desc[0];
713 	/* Output endpoint? Curiousier and curiousier.. */
714 	if (!(ep->bEndpointAddress & USB_DIR_IN))
715 		goto err;
716 	/* If it's not an interrupt endpoint, we'd better punt! */
717 	if ((ep->bmAttributes & 3) != 3)
718 		goto err;
719 	/* We found a hub */
720 	debug("USB hub found\n");
721 	return 0;
722 
723 err:
724 	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
725 	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
726 	      iface->desc.bNumEndpoints);
727 	if (ep) {
728 		debug("   bEndpointAddress=%#x, bmAttributes=%d",
729 		      ep->bEndpointAddress, ep->bmAttributes);
730 	}
731 
732 	return -ENOENT;
733 }
734 
735 int usb_hub_probe(struct usb_device *dev, int ifnum)
736 {
737 	int ret;
738 
739 	ret = usb_hub_check(dev, ifnum);
740 	if (ret)
741 		return 0;
742 	ret = usb_hub_configure(dev);
743 	return ret;
744 }
745 
746 #ifdef CONFIG_DM_USB
747 int usb_hub_scan(struct udevice *hub)
748 {
749 	struct usb_device *udev = dev_get_parent_priv(hub);
750 
751 	return usb_hub_configure(udev);
752 }
753 
754 static int usb_hub_post_probe(struct udevice *dev)
755 {
756 	debug("%s\n", __func__);
757 	return usb_hub_scan(dev);
758 }
759 
760 static const struct udevice_id usb_hub_ids[] = {
761 	{ .compatible = "usb-hub" },
762 	{ }
763 };
764 
765 U_BOOT_DRIVER(usb_generic_hub) = {
766 	.name	= "usb_hub",
767 	.id	= UCLASS_USB_HUB,
768 	.of_match = usb_hub_ids,
769 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
770 };
771 
772 UCLASS_DRIVER(usb_hub) = {
773 	.id		= UCLASS_USB_HUB,
774 	.name		= "usb_hub",
775 	.post_bind	= dm_scan_fdt_dev,
776 	.post_probe	= usb_hub_post_probe,
777 	.child_pre_probe	= usb_child_pre_probe,
778 	.per_child_auto_alloc_size = sizeof(struct usb_device),
779 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
780 };
781 
782 static const struct usb_device_id hub_id_table[] = {
783 	{
784 		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
785 		.bDeviceClass = USB_CLASS_HUB
786 	},
787 	{ }	/* Terminating entry */
788 };
789 
790 U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);
791 
792 #endif
793