xref: /openbmc/u-boot/common/usb_hub.c (revision 33b78476)
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 #ifdef CONFIG_4xx
44 #include <asm/4xx_pci.h>
45 #endif
46 
47 #define USB_BUFSIZ	512
48 
49 #define HUB_SHORT_RESET_TIME	20
50 #define HUB_LONG_RESET_TIME	200
51 
52 #define PORT_OVERCURRENT_MAX_SCAN_COUNT		3
53 
54 struct usb_device_scan {
55 	struct usb_device *dev;		/* USB hub device to scan */
56 	struct usb_hub_device *hub;	/* USB hub struct */
57 	int port;			/* USB port to scan */
58 	struct list_head list;
59 };
60 
61 /* TODO(sjg@chromium.org): Remove this when CONFIG_DM_USB is defined */
62 static struct usb_hub_device hub_dev[USB_MAX_HUB];
63 static int usb_hub_index;
64 static LIST_HEAD(usb_scan_list);
65 
66 __weak void usb_hub_reset_devices(int port)
67 {
68 	return;
69 }
70 
71 static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
72 {
73 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
74 		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
75 		USB_DT_HUB << 8, 0, data, size, USB_CNTL_TIMEOUT);
76 }
77 
78 static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
79 {
80 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
81 				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
82 				port, NULL, 0, USB_CNTL_TIMEOUT);
83 }
84 
85 static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
86 {
87 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
88 				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
89 				port, NULL, 0, USB_CNTL_TIMEOUT);
90 }
91 
92 static int usb_get_hub_status(struct usb_device *dev, void *data)
93 {
94 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
95 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
96 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
97 }
98 
99 int usb_get_port_status(struct usb_device *dev, int port, void *data)
100 {
101 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
102 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
103 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
104 }
105 
106 
107 static void usb_hub_power_on(struct usb_hub_device *hub)
108 {
109 	int i;
110 	struct usb_device *dev;
111 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
112 	const char *env;
113 
114 	dev = hub->pusb_dev;
115 
116 	debug("enabling power on all ports\n");
117 	for (i = 0; i < dev->maxchild; i++) {
118 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
119 		debug("port %d returns %lX\n", i + 1, dev->status);
120 	}
121 
122 #ifdef CONFIG_SANDBOX
123 	/*
124 	 * Don't set timeout / delay values here. This results
125 	 * in these values still being reset to 0.
126 	 */
127 	if (state_get_skip_delays())
128 		return;
129 #endif
130 
131 	/*
132 	 * Wait for power to become stable,
133 	 * plus spec-defined max time for device to connect
134 	 * but allow this time to be increased via env variable as some
135 	 * devices break the spec and require longer warm-up times
136 	 */
137 	env = getenv("usb_pgood_delay");
138 	if (env)
139 		pgood_delay = max(pgood_delay,
140 			          (unsigned)simple_strtol(env, NULL, 0));
141 	debug("pgood_delay=%dms\n", pgood_delay);
142 
143 	/*
144 	 * Do a minimum delay of the larger value of 100ms or pgood_delay
145 	 * so that the power can stablize before the devices are queried
146 	 */
147 	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);
148 
149 	/*
150 	 * Record the power-on timeout here. The max. delay (timeout)
151 	 * will be done based on this value in the USB port loop in
152 	 * usb_hub_configure() later.
153 	 */
154 	hub->connect_timeout = hub->query_delay + 1000;
155 	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
156 	      dev->devnum, max(100, (int)pgood_delay),
157 	      max(100, (int)pgood_delay) + 1000);
158 }
159 
160 void usb_hub_reset(void)
161 {
162 	usb_hub_index = 0;
163 
164 	/* Zero out global hub_dev in case its re-used again */
165 	memset(hub_dev, 0, sizeof(hub_dev));
166 }
167 
168 static struct usb_hub_device *usb_hub_allocate(void)
169 {
170 	if (usb_hub_index < USB_MAX_HUB)
171 		return &hub_dev[usb_hub_index++];
172 
173 	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
174 	return NULL;
175 }
176 
177 #define MAX_TRIES 5
178 
179 static inline char *portspeed(int portstatus)
180 {
181 	char *speed_str;
182 
183 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
184 	case USB_PORT_STAT_SUPER_SPEED:
185 		speed_str = "5 Gb/s";
186 		break;
187 	case USB_PORT_STAT_HIGH_SPEED:
188 		speed_str = "480 Mb/s";
189 		break;
190 	case USB_PORT_STAT_LOW_SPEED:
191 		speed_str = "1.5 Mb/s";
192 		break;
193 	default:
194 		speed_str = "12 Mb/s";
195 		break;
196 	}
197 
198 	return speed_str;
199 }
200 
201 int legacy_hub_port_reset(struct usb_device *dev, int port,
202 			unsigned short *portstat)
203 {
204 	int err, tries;
205 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
206 	unsigned short portstatus, portchange;
207 	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
208 
209 #ifdef CONFIG_DM_USB
210 	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
211 	      port + 1);
212 #else
213 	debug("%s: resetting port %d...\n", __func__, port + 1);
214 #endif
215 	for (tries = 0; tries < MAX_TRIES; tries++) {
216 		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
217 		if (err < 0)
218 			return err;
219 
220 		mdelay(delay);
221 
222 		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
223 			debug("get_port_status failed status %lX\n",
224 			      dev->status);
225 			return -1;
226 		}
227 		portstatus = le16_to_cpu(portsts->wPortStatus);
228 		portchange = le16_to_cpu(portsts->wPortChange);
229 
230 		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
231 							portspeed(portstatus));
232 
233 		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
234 		      "  USB_PORT_STAT_ENABLE %d\n",
235 		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
236 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
237 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
238 
239 		/*
240 		 * Perhaps we should check for the following here:
241 		 * - C_CONNECTION hasn't been set.
242 		 * - CONNECTION is still set.
243 		 *
244 		 * Doing so would ensure that the device is still connected
245 		 * to the bus, and hasn't been unplugged or replaced while the
246 		 * USB bus reset was going on.
247 		 *
248 		 * However, if we do that, then (at least) a San Disk Ultra
249 		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
250 		 * Tegra Jetson TK1 board. For some reason, the device appears
251 		 * to briefly drop off the bus when this second bus reset is
252 		 * executed, yet if we retry this loop, it'll eventually come
253 		 * back after another reset or two.
254 		 */
255 
256 		if (portstatus & USB_PORT_STAT_ENABLE)
257 			break;
258 
259 		/* Switch to long reset delay for the next round */
260 		delay = HUB_LONG_RESET_TIME;
261 	}
262 
263 	if (tries == MAX_TRIES) {
264 		debug("Cannot enable port %i after %i retries, " \
265 		      "disabling port.\n", port + 1, MAX_TRIES);
266 		debug("Maybe the USB cable is bad?\n");
267 		return -1;
268 	}
269 
270 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
271 	*portstat = portstatus;
272 	return 0;
273 }
274 
275 #ifdef CONFIG_DM_USB
276 int hub_port_reset(struct udevice *dev, int port, unsigned short *portstat)
277 {
278 	struct usb_device *udev = dev_get_parent_priv(dev);
279 
280 	return legacy_hub_port_reset(udev, port, portstat);
281 }
282 #endif
283 
284 int usb_hub_port_connect_change(struct usb_device *dev, int port)
285 {
286 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
287 	unsigned short portstatus;
288 	int ret, speed;
289 
290 	/* Check status */
291 	ret = usb_get_port_status(dev, port + 1, portsts);
292 	if (ret < 0) {
293 		debug("get_port_status failed\n");
294 		return ret;
295 	}
296 
297 	portstatus = le16_to_cpu(portsts->wPortStatus);
298 	debug("portstatus %x, change %x, %s\n",
299 	      portstatus,
300 	      le16_to_cpu(portsts->wPortChange),
301 	      portspeed(portstatus));
302 
303 	/* Clear the connection change status */
304 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);
305 
306 	/* Disconnect any existing devices under this port */
307 	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
308 	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
309 	    usb_device_has_child_on_port(dev, port)) {
310 		debug("usb_disconnect(&hub->children[port]);\n");
311 		/* Return now if nothing is connected */
312 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
313 			return -ENOTCONN;
314 	}
315 
316 	/* Reset the port */
317 	ret = legacy_hub_port_reset(dev, port, &portstatus);
318 	if (ret < 0) {
319 		if (ret != -ENXIO)
320 			printf("cannot reset port %i!?\n", port + 1);
321 		return ret;
322 	}
323 
324 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
325 	case USB_PORT_STAT_SUPER_SPEED:
326 		speed = USB_SPEED_SUPER;
327 		break;
328 	case USB_PORT_STAT_HIGH_SPEED:
329 		speed = USB_SPEED_HIGH;
330 		break;
331 	case USB_PORT_STAT_LOW_SPEED:
332 		speed = USB_SPEED_LOW;
333 		break;
334 	default:
335 		speed = USB_SPEED_FULL;
336 		break;
337 	}
338 
339 #ifdef CONFIG_DM_USB
340 	struct udevice *child;
341 
342 	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
343 #else
344 	struct usb_device *usb;
345 
346 	ret = usb_alloc_new_device(dev->controller, &usb);
347 	if (ret) {
348 		printf("cannot create new device: ret=%d", ret);
349 		return ret;
350 	}
351 
352 	dev->children[port] = usb;
353 	usb->speed = speed;
354 	usb->parent = dev;
355 	usb->portnr = port + 1;
356 	/* Run it through the hoops (find a driver, etc) */
357 	ret = usb_new_device(usb);
358 	if (ret < 0) {
359 		/* Woops, disable the port */
360 		usb_free_device(dev->controller);
361 		dev->children[port] = NULL;
362 	}
363 #endif
364 	if (ret < 0) {
365 		debug("hub: disabling port %d\n", port + 1);
366 		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
367 	}
368 
369 	return ret;
370 }
371 
372 static int usb_scan_port(struct usb_device_scan *usb_scan)
373 {
374 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
375 	unsigned short portstatus;
376 	unsigned short portchange;
377 	struct usb_device *dev;
378 	struct usb_hub_device *hub;
379 	int ret = 0;
380 	int i;
381 
382 	dev = usb_scan->dev;
383 	hub = usb_scan->hub;
384 	i = usb_scan->port;
385 
386 	/*
387 	 * Don't talk to the device before the query delay is expired.
388 	 * This is needed for voltages to stabalize.
389 	 */
390 	if (get_timer(0) < hub->query_delay)
391 		return 0;
392 
393 	ret = usb_get_port_status(dev, i + 1, portsts);
394 	if (ret < 0) {
395 		debug("get_port_status failed\n");
396 		if (get_timer(0) >= hub->connect_timeout) {
397 			debug("devnum=%d port=%d: timeout\n",
398 			      dev->devnum, i + 1);
399 			/* Remove this device from scanning list */
400 			list_del(&usb_scan->list);
401 			free(usb_scan);
402 			return 0;
403 		}
404 		return 0;
405 	}
406 
407 	portstatus = le16_to_cpu(portsts->wPortStatus);
408 	portchange = le16_to_cpu(portsts->wPortChange);
409 	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
410 
411 	/* No connection change happened, wait a bit more. */
412 	if (!(portchange & USB_PORT_STAT_C_CONNECTION)) {
413 		if (get_timer(0) >= hub->connect_timeout) {
414 			debug("devnum=%d port=%d: timeout\n",
415 			      dev->devnum, i + 1);
416 			/* Remove this device from scanning list */
417 			list_del(&usb_scan->list);
418 			free(usb_scan);
419 			return 0;
420 		}
421 		return 0;
422 	}
423 
424 	/* Test if the connection came up, and if not exit */
425 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
426 		return 0;
427 
428 	/* A new USB device is ready at this point */
429 	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);
430 
431 	usb_hub_port_connect_change(dev, i);
432 
433 	if (portchange & USB_PORT_STAT_C_ENABLE) {
434 		debug("port %d enable change, status %x\n", i + 1, portstatus);
435 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
436 		/*
437 		 * The following hack causes a ghost device problem
438 		 * to Faraday EHCI
439 		 */
440 #ifndef CONFIG_USB_EHCI_FARADAY
441 		/*
442 		 * EM interference sometimes causes bad shielded USB
443 		 * devices to be shutdown by the hub, this hack enables
444 		 * them again. Works at least with mouse driver
445 		 */
446 		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
447 		    (portstatus & USB_PORT_STAT_CONNECTION) &&
448 		    usb_device_has_child_on_port(dev, i)) {
449 			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
450 			      i + 1);
451 			usb_hub_port_connect_change(dev, i);
452 		}
453 #endif
454 	}
455 
456 	if (portstatus & USB_PORT_STAT_SUSPEND) {
457 		debug("port %d suspend change\n", i + 1);
458 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
459 	}
460 
461 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
462 		debug("port %d over-current change\n", i + 1);
463 		usb_clear_port_feature(dev, i + 1,
464 				       USB_PORT_FEAT_C_OVER_CURRENT);
465 		/* Only power-on this one port */
466 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
467 		hub->overcurrent_count[i]++;
468 
469 		/*
470 		 * If the max-scan-count is not reached, return without removing
471 		 * the device from scan-list. This will re-issue a new scan.
472 		 */
473 		if (hub->overcurrent_count[i] <=
474 		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
475 			return 0;
476 
477 		/* Otherwise the device will get removed */
478 		printf("Port %d over-current occurred %d times\n", i + 1,
479 		       hub->overcurrent_count[i]);
480 	}
481 
482 	if (portchange & USB_PORT_STAT_C_RESET) {
483 		debug("port %d reset change\n", i + 1);
484 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
485 	}
486 
487 	/*
488 	 * We're done with this device, so let's remove this device from
489 	 * scanning list
490 	 */
491 	list_del(&usb_scan->list);
492 	free(usb_scan);
493 
494 	return 0;
495 }
496 
497 static int usb_device_list_scan(void)
498 {
499 	struct usb_device_scan *usb_scan;
500 	struct usb_device_scan *tmp;
501 	static int running;
502 	int ret = 0;
503 
504 	/* Only run this loop once for each controller */
505 	if (running)
506 		return 0;
507 
508 	running = 1;
509 
510 	while (1) {
511 		/* We're done, once the list is empty again */
512 		if (list_empty(&usb_scan_list))
513 			goto out;
514 
515 		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
516 			int ret;
517 
518 			/* Scan this port */
519 			ret = usb_scan_port(usb_scan);
520 			if (ret)
521 				goto out;
522 		}
523 	}
524 
525 out:
526 	/*
527 	 * This USB controller has finished scanning all its connected
528 	 * USB devices. Set "running" back to 0, so that other USB controllers
529 	 * will scan their devices too.
530 	 */
531 	running = 0;
532 
533 	return ret;
534 }
535 
536 static int usb_hub_configure(struct usb_device *dev)
537 {
538 	int i, length;
539 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
540 	unsigned char *bitmap;
541 	short hubCharacteristics;
542 	struct usb_hub_descriptor *descriptor;
543 	struct usb_hub_device *hub;
544 	__maybe_unused struct usb_hub_status *hubsts;
545 	int ret;
546 
547 	/* "allocate" Hub device */
548 	hub = usb_hub_allocate();
549 	if (hub == NULL)
550 		return -ENOMEM;
551 	hub->pusb_dev = dev;
552 	/* Get the the hub descriptor */
553 	ret = usb_get_hub_descriptor(dev, buffer, 4);
554 	if (ret < 0) {
555 		debug("usb_hub_configure: failed to get hub " \
556 		      "descriptor, giving up %lX\n", dev->status);
557 		return ret;
558 	}
559 	descriptor = (struct usb_hub_descriptor *)buffer;
560 
561 	length = min_t(int, descriptor->bLength,
562 		       sizeof(struct usb_hub_descriptor));
563 
564 	ret = usb_get_hub_descriptor(dev, buffer, length);
565 	if (ret < 0) {
566 		debug("usb_hub_configure: failed to get hub " \
567 		      "descriptor 2nd giving up %lX\n", dev->status);
568 		return ret;
569 	}
570 	memcpy((unsigned char *)&hub->desc, buffer, length);
571 	/* adjust 16bit values */
572 	put_unaligned(le16_to_cpu(get_unaligned(
573 			&descriptor->wHubCharacteristics)),
574 			&hub->desc.wHubCharacteristics);
575 	/* set the bitmap */
576 	bitmap = (unsigned char *)&hub->desc.DeviceRemovable[0];
577 	/* devices not removable by default */
578 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
579 	bitmap = (unsigned char *)&hub->desc.PortPowerCtrlMask[0];
580 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */
581 
582 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
583 		hub->desc.DeviceRemovable[i] = descriptor->DeviceRemovable[i];
584 
585 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
586 		hub->desc.PortPowerCtrlMask[i] = descriptor->PortPowerCtrlMask[i];
587 
588 	dev->maxchild = descriptor->bNbrPorts;
589 	debug("%d ports detected\n", dev->maxchild);
590 
591 	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
592 	switch (hubCharacteristics & HUB_CHAR_LPSM) {
593 	case 0x00:
594 		debug("ganged power switching\n");
595 		break;
596 	case 0x01:
597 		debug("individual port power switching\n");
598 		break;
599 	case 0x02:
600 	case 0x03:
601 		debug("unknown reserved power switching mode\n");
602 		break;
603 	}
604 
605 	if (hubCharacteristics & HUB_CHAR_COMPOUND)
606 		debug("part of a compound device\n");
607 	else
608 		debug("standalone hub\n");
609 
610 	switch (hubCharacteristics & HUB_CHAR_OCPM) {
611 	case 0x00:
612 		debug("global over-current protection\n");
613 		break;
614 	case 0x08:
615 		debug("individual port over-current protection\n");
616 		break;
617 	case 0x10:
618 	case 0x18:
619 		debug("no over-current protection\n");
620 		break;
621 	}
622 
623 	debug("power on to power good time: %dms\n",
624 	      descriptor->bPwrOn2PwrGood * 2);
625 	debug("hub controller current requirement: %dmA\n",
626 	      descriptor->bHubContrCurrent);
627 
628 	for (i = 0; i < dev->maxchild; i++)
629 		debug("port %d is%s removable\n", i + 1,
630 		      hub->desc.DeviceRemovable[(i + 1) / 8] & \
631 		      (1 << ((i + 1) % 8)) ? " not" : "");
632 
633 	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
634 		debug("usb_hub_configure: failed to get Status - " \
635 		      "too long: %d\n", descriptor->bLength);
636 		return -EFBIG;
637 	}
638 
639 	ret = usb_get_hub_status(dev, buffer);
640 	if (ret < 0) {
641 		debug("usb_hub_configure: failed to get Status %lX\n",
642 		      dev->status);
643 		return ret;
644 	}
645 
646 #ifdef DEBUG
647 	hubsts = (struct usb_hub_status *)buffer;
648 #endif
649 
650 	debug("get_hub_status returned status %X, change %X\n",
651 	      le16_to_cpu(hubsts->wHubStatus),
652 	      le16_to_cpu(hubsts->wHubChange));
653 	debug("local power source is %s\n",
654 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
655 	      "lost (inactive)" : "good");
656 	debug("%sover-current condition exists\n",
657 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
658 	      "" : "no ");
659 	usb_hub_power_on(hub);
660 
661 	/*
662 	 * Reset any devices that may be in a bad state when applying
663 	 * the power.  This is a __weak function.  Resetting of the devices
664 	 * should occur in the board file of the device.
665 	 */
666 	for (i = 0; i < dev->maxchild; i++)
667 		usb_hub_reset_devices(i + 1);
668 
669 	/*
670 	 * Only add the connected USB devices, including potential hubs,
671 	 * to a scanning list. This list will get scanned and devices that
672 	 * are detected (either via port connected or via port timeout)
673 	 * will get removed from this list. Scanning of the devices on this
674 	 * list will continue until all devices are removed.
675 	 */
676 	for (i = 0; i < dev->maxchild; i++) {
677 		struct usb_device_scan *usb_scan;
678 
679 		usb_scan = calloc(1, sizeof(*usb_scan));
680 		if (!usb_scan) {
681 			printf("Can't allocate memory for USB device!\n");
682 			return -ENOMEM;
683 		}
684 		usb_scan->dev = dev;
685 		usb_scan->hub = hub;
686 		usb_scan->port = i;
687 		list_add_tail(&usb_scan->list, &usb_scan_list);
688 	}
689 
690 	/*
691 	 * And now call the scanning code which loops over the generated list
692 	 */
693 	ret = usb_device_list_scan();
694 
695 	return ret;
696 }
697 
698 static int usb_hub_check(struct usb_device *dev, int ifnum)
699 {
700 	struct usb_interface *iface;
701 	struct usb_endpoint_descriptor *ep = NULL;
702 
703 	iface = &dev->config.if_desc[ifnum];
704 	/* Is it a hub? */
705 	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
706 		goto err;
707 	/* Some hubs have a subclass of 1, which AFAICT according to the */
708 	/*  specs is not defined, but it works */
709 	if ((iface->desc.bInterfaceSubClass != 0) &&
710 	    (iface->desc.bInterfaceSubClass != 1))
711 		goto err;
712 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
713 	if (iface->desc.bNumEndpoints != 1)
714 		goto err;
715 	ep = &iface->ep_desc[0];
716 	/* Output endpoint? Curiousier and curiousier.. */
717 	if (!(ep->bEndpointAddress & USB_DIR_IN))
718 		goto err;
719 	/* If it's not an interrupt endpoint, we'd better punt! */
720 	if ((ep->bmAttributes & 3) != 3)
721 		goto err;
722 	/* We found a hub */
723 	debug("USB hub found\n");
724 	return 0;
725 
726 err:
727 	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
728 	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
729 	      iface->desc.bNumEndpoints);
730 	if (ep) {
731 		debug("   bEndpointAddress=%#x, bmAttributes=%d",
732 		      ep->bEndpointAddress, ep->bmAttributes);
733 	}
734 
735 	return -ENOENT;
736 }
737 
738 int usb_hub_probe(struct usb_device *dev, int ifnum)
739 {
740 	int ret;
741 
742 	ret = usb_hub_check(dev, ifnum);
743 	if (ret)
744 		return 0;
745 	ret = usb_hub_configure(dev);
746 	return ret;
747 }
748 
749 #ifdef CONFIG_DM_USB
750 int usb_hub_scan(struct udevice *hub)
751 {
752 	struct usb_device *udev = dev_get_parent_priv(hub);
753 
754 	return usb_hub_configure(udev);
755 }
756 
757 static int usb_hub_post_probe(struct udevice *dev)
758 {
759 	debug("%s\n", __func__);
760 	return usb_hub_scan(dev);
761 }
762 
763 static const struct udevice_id usb_hub_ids[] = {
764 	{ .compatible = "usb-hub" },
765 	{ }
766 };
767 
768 U_BOOT_DRIVER(usb_generic_hub) = {
769 	.name	= "usb_hub",
770 	.id	= UCLASS_USB_HUB,
771 	.of_match = usb_hub_ids,
772 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
773 };
774 
775 UCLASS_DRIVER(usb_hub) = {
776 	.id		= UCLASS_USB_HUB,
777 	.name		= "usb_hub",
778 	.post_bind	= dm_scan_fdt_dev,
779 	.post_probe	= usb_hub_post_probe,
780 	.child_pre_probe	= usb_child_pre_probe,
781 	.per_child_auto_alloc_size = sizeof(struct usb_device),
782 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
783 };
784 
785 static const struct usb_device_id hub_id_table[] = {
786 	{
787 		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
788 		.bDeviceClass = USB_CLASS_HUB
789 	},
790 	{ }	/* Terminating entry */
791 };
792 
793 U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);
794 
795 #endif
796