xref: /openbmc/u-boot/common/usb_hub.c (revision c72c161b)
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 static LIST_HEAD(usb_scan_list);
59 
60 __weak void usb_hub_reset_devices(int port)
61 {
62 	return;
63 }
64 
65 static inline bool usb_hub_is_superspeed(struct usb_device *hdev)
66 {
67 	return hdev->descriptor.bDeviceProtocol == 3;
68 }
69 
70 #ifdef CONFIG_DM_USB
71 bool usb_hub_is_root_hub(struct udevice *hub)
72 {
73 	if (device_get_uclass_id(hub->parent) != UCLASS_USB_HUB)
74 		return true;
75 
76 	return false;
77 }
78 
79 static int usb_set_hub_depth(struct usb_device *dev, int depth)
80 {
81 	if (depth < 0 || depth > 4)
82 		return -EINVAL;
83 
84 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
85 		USB_REQ_SET_HUB_DEPTH, USB_DIR_OUT | USB_RT_HUB,
86 		depth, 0, NULL, 0, USB_CNTL_TIMEOUT);
87 }
88 #endif
89 
90 static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
91 {
92 	unsigned short dtype = USB_DT_HUB;
93 
94 	if (usb_hub_is_superspeed(dev))
95 		dtype = USB_DT_SS_HUB;
96 
97 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
98 		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
99 		dtype << 8, 0, data, size, USB_CNTL_TIMEOUT);
100 }
101 
102 static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
103 {
104 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
105 				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
106 				port, NULL, 0, USB_CNTL_TIMEOUT);
107 }
108 
109 static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
110 {
111 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
112 				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
113 				port, NULL, 0, USB_CNTL_TIMEOUT);
114 }
115 
116 static int usb_get_hub_status(struct usb_device *dev, void *data)
117 {
118 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
119 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
120 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
121 }
122 
123 int usb_get_port_status(struct usb_device *dev, int port, void *data)
124 {
125 	int ret;
126 
127 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
128 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
129 			data, sizeof(struct usb_port_status), USB_CNTL_TIMEOUT);
130 
131 #ifdef CONFIG_DM_USB
132 	if (ret < 0)
133 		return ret;
134 
135 	/*
136 	 * Translate the USB 3.0 hub port status field into the old version
137 	 * that U-Boot understands. Do this only when the hub is not root hub.
138 	 * For root hub, the port status field has already been translated
139 	 * in the host controller driver (see xhci_submit_root() in xhci.c).
140 	 *
141 	 * Note: this only supports driver model.
142 	 */
143 
144 	if (!usb_hub_is_root_hub(dev->dev) && usb_hub_is_superspeed(dev)) {
145 		struct usb_port_status *status = (struct usb_port_status *)data;
146 		u16 tmp = (status->wPortStatus) & USB_SS_PORT_STAT_MASK;
147 
148 		if (status->wPortStatus & USB_SS_PORT_STAT_POWER)
149 			tmp |= USB_PORT_STAT_POWER;
150 		if ((status->wPortStatus & USB_SS_PORT_STAT_SPEED) ==
151 		    USB_SS_PORT_STAT_SPEED_5GBPS)
152 			tmp |= USB_PORT_STAT_SUPER_SPEED;
153 
154 		status->wPortStatus = tmp;
155 	}
156 #endif
157 
158 	return ret;
159 }
160 
161 
162 static void usb_hub_power_on(struct usb_hub_device *hub)
163 {
164 	int i;
165 	struct usb_device *dev;
166 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
167 	const char *env;
168 
169 	dev = hub->pusb_dev;
170 
171 	debug("enabling power on all ports\n");
172 	for (i = 0; i < dev->maxchild; i++) {
173 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
174 		debug("port %d returns %lX\n", i + 1, dev->status);
175 	}
176 
177 #ifdef CONFIG_SANDBOX
178 	/*
179 	 * Don't set timeout / delay values here. This results
180 	 * in these values still being reset to 0.
181 	 */
182 	if (state_get_skip_delays())
183 		return;
184 #endif
185 
186 	/*
187 	 * Wait for power to become stable,
188 	 * plus spec-defined max time for device to connect
189 	 * but allow this time to be increased via env variable as some
190 	 * devices break the spec and require longer warm-up times
191 	 */
192 	env = getenv("usb_pgood_delay");
193 	if (env)
194 		pgood_delay = max(pgood_delay,
195 			          (unsigned)simple_strtol(env, NULL, 0));
196 	debug("pgood_delay=%dms\n", pgood_delay);
197 
198 	/*
199 	 * Do a minimum delay of the larger value of 100ms or pgood_delay
200 	 * so that the power can stablize before the devices are queried
201 	 */
202 	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);
203 
204 	/*
205 	 * Record the power-on timeout here. The max. delay (timeout)
206 	 * will be done based on this value in the USB port loop in
207 	 * usb_hub_configure() later.
208 	 */
209 	hub->connect_timeout = hub->query_delay + 1000;
210 	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
211 	      dev->devnum, max(100, (int)pgood_delay),
212 	      max(100, (int)pgood_delay) + 1000);
213 }
214 
215 #ifndef CONFIG_DM_USB
216 static struct usb_hub_device hub_dev[USB_MAX_HUB];
217 static int usb_hub_index;
218 
219 void usb_hub_reset(void)
220 {
221 	usb_hub_index = 0;
222 
223 	/* Zero out global hub_dev in case its re-used again */
224 	memset(hub_dev, 0, sizeof(hub_dev));
225 }
226 
227 static struct usb_hub_device *usb_hub_allocate(void)
228 {
229 	if (usb_hub_index < USB_MAX_HUB)
230 		return &hub_dev[usb_hub_index++];
231 
232 	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
233 	return NULL;
234 }
235 #endif
236 
237 #define MAX_TRIES 5
238 
239 static inline char *portspeed(int portstatus)
240 {
241 	char *speed_str;
242 
243 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
244 	case USB_PORT_STAT_SUPER_SPEED:
245 		speed_str = "5 Gb/s";
246 		break;
247 	case USB_PORT_STAT_HIGH_SPEED:
248 		speed_str = "480 Mb/s";
249 		break;
250 	case USB_PORT_STAT_LOW_SPEED:
251 		speed_str = "1.5 Mb/s";
252 		break;
253 	default:
254 		speed_str = "12 Mb/s";
255 		break;
256 	}
257 
258 	return speed_str;
259 }
260 
261 /**
262  * usb_hub_port_reset() - reset a port given its usb_device pointer
263  *
264  * Reset a hub port and see if a device is present on that port, providing
265  * sufficient time for it to show itself. The port status is returned.
266  *
267  * @dev:	USB device to reset
268  * @port:	Port number to reset (note ports are numbered from 0 here)
269  * @portstat:	Returns port status
270  */
271 static int usb_hub_port_reset(struct usb_device *dev, int port,
272 			      unsigned short *portstat)
273 {
274 	int err, tries;
275 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
276 	unsigned short portstatus, portchange;
277 	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
278 
279 #ifdef CONFIG_DM_USB
280 	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
281 	      port + 1);
282 #else
283 	debug("%s: resetting port %d...\n", __func__, port + 1);
284 #endif
285 	for (tries = 0; tries < MAX_TRIES; tries++) {
286 		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
287 		if (err < 0)
288 			return err;
289 
290 		mdelay(delay);
291 
292 		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
293 			debug("get_port_status failed status %lX\n",
294 			      dev->status);
295 			return -1;
296 		}
297 		portstatus = le16_to_cpu(portsts->wPortStatus);
298 		portchange = le16_to_cpu(portsts->wPortChange);
299 
300 		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
301 							portspeed(portstatus));
302 
303 		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
304 		      "  USB_PORT_STAT_ENABLE %d\n",
305 		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
306 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
307 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
308 
309 		/*
310 		 * Perhaps we should check for the following here:
311 		 * - C_CONNECTION hasn't been set.
312 		 * - CONNECTION is still set.
313 		 *
314 		 * Doing so would ensure that the device is still connected
315 		 * to the bus, and hasn't been unplugged or replaced while the
316 		 * USB bus reset was going on.
317 		 *
318 		 * However, if we do that, then (at least) a San Disk Ultra
319 		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
320 		 * Tegra Jetson TK1 board. For some reason, the device appears
321 		 * to briefly drop off the bus when this second bus reset is
322 		 * executed, yet if we retry this loop, it'll eventually come
323 		 * back after another reset or two.
324 		 */
325 
326 		if (portstatus & USB_PORT_STAT_ENABLE)
327 			break;
328 
329 		/* Switch to long reset delay for the next round */
330 		delay = HUB_LONG_RESET_TIME;
331 	}
332 
333 	if (tries == MAX_TRIES) {
334 		debug("Cannot enable port %i after %i retries, " \
335 		      "disabling port.\n", port + 1, MAX_TRIES);
336 		debug("Maybe the USB cable is bad?\n");
337 		return -1;
338 	}
339 
340 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
341 	*portstat = portstatus;
342 	return 0;
343 }
344 
345 int usb_hub_port_connect_change(struct usb_device *dev, int port)
346 {
347 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
348 	unsigned short portstatus;
349 	int ret, speed;
350 
351 	/* Check status */
352 	ret = usb_get_port_status(dev, port + 1, portsts);
353 	if (ret < 0) {
354 		debug("get_port_status failed\n");
355 		return ret;
356 	}
357 
358 	portstatus = le16_to_cpu(portsts->wPortStatus);
359 	debug("portstatus %x, change %x, %s\n",
360 	      portstatus,
361 	      le16_to_cpu(portsts->wPortChange),
362 	      portspeed(portstatus));
363 
364 	/* Clear the connection change status */
365 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);
366 
367 	/* Disconnect any existing devices under this port */
368 	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
369 	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
370 	    usb_device_has_child_on_port(dev, port)) {
371 		debug("usb_disconnect(&hub->children[port]);\n");
372 		/* Return now if nothing is connected */
373 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
374 			return -ENOTCONN;
375 	}
376 
377 	/* Reset the port */
378 	ret = usb_hub_port_reset(dev, port, &portstatus);
379 	if (ret < 0) {
380 		if (ret != -ENXIO)
381 			printf("cannot reset port %i!?\n", port + 1);
382 		return ret;
383 	}
384 
385 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
386 	case USB_PORT_STAT_SUPER_SPEED:
387 		speed = USB_SPEED_SUPER;
388 		break;
389 	case USB_PORT_STAT_HIGH_SPEED:
390 		speed = USB_SPEED_HIGH;
391 		break;
392 	case USB_PORT_STAT_LOW_SPEED:
393 		speed = USB_SPEED_LOW;
394 		break;
395 	default:
396 		speed = USB_SPEED_FULL;
397 		break;
398 	}
399 
400 #ifdef CONFIG_DM_USB
401 	struct udevice *child;
402 
403 	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
404 #else
405 	struct usb_device *usb;
406 
407 	ret = usb_alloc_new_device(dev->controller, &usb);
408 	if (ret) {
409 		printf("cannot create new device: ret=%d", ret);
410 		return ret;
411 	}
412 
413 	dev->children[port] = usb;
414 	usb->speed = speed;
415 	usb->parent = dev;
416 	usb->portnr = port + 1;
417 	/* Run it through the hoops (find a driver, etc) */
418 	ret = usb_new_device(usb);
419 	if (ret < 0) {
420 		/* Woops, disable the port */
421 		usb_free_device(dev->controller);
422 		dev->children[port] = NULL;
423 	}
424 #endif
425 	if (ret < 0) {
426 		debug("hub: disabling port %d\n", port + 1);
427 		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
428 	}
429 
430 	return ret;
431 }
432 
433 static int usb_scan_port(struct usb_device_scan *usb_scan)
434 {
435 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
436 	unsigned short portstatus;
437 	unsigned short portchange;
438 	struct usb_device *dev;
439 	struct usb_hub_device *hub;
440 	int ret = 0;
441 	int i;
442 
443 	dev = usb_scan->dev;
444 	hub = usb_scan->hub;
445 	i = usb_scan->port;
446 
447 	/*
448 	 * Don't talk to the device before the query delay is expired.
449 	 * This is needed for voltages to stabalize.
450 	 */
451 	if (get_timer(0) < hub->query_delay)
452 		return 0;
453 
454 	ret = usb_get_port_status(dev, i + 1, portsts);
455 	if (ret < 0) {
456 		debug("get_port_status failed\n");
457 		if (get_timer(0) >= hub->connect_timeout) {
458 			debug("devnum=%d port=%d: timeout\n",
459 			      dev->devnum, i + 1);
460 			/* Remove this device from scanning list */
461 			list_del(&usb_scan->list);
462 			free(usb_scan);
463 			return 0;
464 		}
465 		return 0;
466 	}
467 
468 	portstatus = le16_to_cpu(portsts->wPortStatus);
469 	portchange = le16_to_cpu(portsts->wPortChange);
470 	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
471 
472 	/*
473 	 * No connection change happened, wait a bit more.
474 	 *
475 	 * For some situation, the hub reports no connection change but a
476 	 * device is connected to the port (eg: CCS bit is set but CSC is not
477 	 * in the PORTSC register of a root hub), ignore such case.
478 	 */
479 	if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
480 	    !(portstatus & USB_PORT_STAT_CONNECTION)) {
481 		if (get_timer(0) >= hub->connect_timeout) {
482 			debug("devnum=%d port=%d: timeout\n",
483 			      dev->devnum, i + 1);
484 			/* Remove this device from scanning list */
485 			list_del(&usb_scan->list);
486 			free(usb_scan);
487 			return 0;
488 		}
489 		return 0;
490 	}
491 
492 	/* A new USB device is ready at this point */
493 	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);
494 
495 	usb_hub_port_connect_change(dev, i);
496 
497 	if (portchange & USB_PORT_STAT_C_ENABLE) {
498 		debug("port %d enable change, status %x\n", i + 1, portstatus);
499 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
500 		/*
501 		 * The following hack causes a ghost device problem
502 		 * to Faraday EHCI
503 		 */
504 #ifndef CONFIG_USB_EHCI_FARADAY
505 		/*
506 		 * EM interference sometimes causes bad shielded USB
507 		 * devices to be shutdown by the hub, this hack enables
508 		 * them again. Works at least with mouse driver
509 		 */
510 		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
511 		    (portstatus & USB_PORT_STAT_CONNECTION) &&
512 		    usb_device_has_child_on_port(dev, i)) {
513 			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
514 			      i + 1);
515 			usb_hub_port_connect_change(dev, i);
516 		}
517 #endif
518 	}
519 
520 	if (portstatus & USB_PORT_STAT_SUSPEND) {
521 		debug("port %d suspend change\n", i + 1);
522 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
523 	}
524 
525 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
526 		debug("port %d over-current change\n", i + 1);
527 		usb_clear_port_feature(dev, i + 1,
528 				       USB_PORT_FEAT_C_OVER_CURRENT);
529 		/* Only power-on this one port */
530 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
531 		hub->overcurrent_count[i]++;
532 
533 		/*
534 		 * If the max-scan-count is not reached, return without removing
535 		 * the device from scan-list. This will re-issue a new scan.
536 		 */
537 		if (hub->overcurrent_count[i] <=
538 		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
539 			return 0;
540 
541 		/* Otherwise the device will get removed */
542 		printf("Port %d over-current occurred %d times\n", i + 1,
543 		       hub->overcurrent_count[i]);
544 	}
545 
546 	if (portchange & USB_PORT_STAT_C_RESET) {
547 		debug("port %d reset change\n", i + 1);
548 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
549 	}
550 
551 	/*
552 	 * We're done with this device, so let's remove this device from
553 	 * scanning list
554 	 */
555 	list_del(&usb_scan->list);
556 	free(usb_scan);
557 
558 	return 0;
559 }
560 
561 static int usb_device_list_scan(void)
562 {
563 	struct usb_device_scan *usb_scan;
564 	struct usb_device_scan *tmp;
565 	static int running;
566 	int ret = 0;
567 
568 	/* Only run this loop once for each controller */
569 	if (running)
570 		return 0;
571 
572 	running = 1;
573 
574 	while (1) {
575 		/* We're done, once the list is empty again */
576 		if (list_empty(&usb_scan_list))
577 			goto out;
578 
579 		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
580 			int ret;
581 
582 			/* Scan this port */
583 			ret = usb_scan_port(usb_scan);
584 			if (ret)
585 				goto out;
586 		}
587 	}
588 
589 out:
590 	/*
591 	 * This USB controller has finished scanning all its connected
592 	 * USB devices. Set "running" back to 0, so that other USB controllers
593 	 * will scan their devices too.
594 	 */
595 	running = 0;
596 
597 	return ret;
598 }
599 
600 static struct usb_hub_device *usb_get_hub_device(struct usb_device *dev)
601 {
602 	struct usb_hub_device *hub;
603 
604 #ifndef CONFIG_DM_USB
605 	/* "allocate" Hub device */
606 	hub = usb_hub_allocate();
607 #else
608 	hub = dev_get_uclass_priv(dev->dev);
609 #endif
610 
611 	return hub;
612 }
613 
614 static int usb_hub_configure(struct usb_device *dev)
615 {
616 	int i, length;
617 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
618 	unsigned char *bitmap;
619 	short hubCharacteristics;
620 	struct usb_hub_descriptor *descriptor;
621 	struct usb_hub_device *hub;
622 	__maybe_unused struct usb_hub_status *hubsts;
623 	int ret;
624 
625 	hub = usb_get_hub_device(dev);
626 	if (hub == NULL)
627 		return -ENOMEM;
628 	hub->pusb_dev = dev;
629 
630 	/* Get the the hub descriptor */
631 	ret = usb_get_hub_descriptor(dev, buffer, 4);
632 	if (ret < 0) {
633 		debug("usb_hub_configure: failed to get hub " \
634 		      "descriptor, giving up %lX\n", dev->status);
635 		return ret;
636 	}
637 	descriptor = (struct usb_hub_descriptor *)buffer;
638 
639 	length = min_t(int, descriptor->bLength,
640 		       sizeof(struct usb_hub_descriptor));
641 
642 	ret = usb_get_hub_descriptor(dev, buffer, length);
643 	if (ret < 0) {
644 		debug("usb_hub_configure: failed to get hub " \
645 		      "descriptor 2nd giving up %lX\n", dev->status);
646 		return ret;
647 	}
648 	memcpy((unsigned char *)&hub->desc, buffer, length);
649 	/* adjust 16bit values */
650 	put_unaligned(le16_to_cpu(get_unaligned(
651 			&descriptor->wHubCharacteristics)),
652 			&hub->desc.wHubCharacteristics);
653 	/* set the bitmap */
654 	bitmap = (unsigned char *)&hub->desc.u.hs.DeviceRemovable[0];
655 	/* devices not removable by default */
656 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
657 	bitmap = (unsigned char *)&hub->desc.u.hs.PortPowerCtrlMask[0];
658 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */
659 
660 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
661 		hub->desc.u.hs.DeviceRemovable[i] =
662 			descriptor->u.hs.DeviceRemovable[i];
663 
664 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
665 		hub->desc.u.hs.PortPowerCtrlMask[i] =
666 			descriptor->u.hs.PortPowerCtrlMask[i];
667 
668 	dev->maxchild = descriptor->bNbrPorts;
669 	debug("%d ports detected\n", dev->maxchild);
670 
671 	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
672 	switch (hubCharacteristics & HUB_CHAR_LPSM) {
673 	case 0x00:
674 		debug("ganged power switching\n");
675 		break;
676 	case 0x01:
677 		debug("individual port power switching\n");
678 		break;
679 	case 0x02:
680 	case 0x03:
681 		debug("unknown reserved power switching mode\n");
682 		break;
683 	}
684 
685 	if (hubCharacteristics & HUB_CHAR_COMPOUND)
686 		debug("part of a compound device\n");
687 	else
688 		debug("standalone hub\n");
689 
690 	switch (hubCharacteristics & HUB_CHAR_OCPM) {
691 	case 0x00:
692 		debug("global over-current protection\n");
693 		break;
694 	case 0x08:
695 		debug("individual port over-current protection\n");
696 		break;
697 	case 0x10:
698 	case 0x18:
699 		debug("no over-current protection\n");
700 		break;
701 	}
702 
703 	switch (dev->descriptor.bDeviceProtocol) {
704 	case USB_HUB_PR_FS:
705 		break;
706 	case USB_HUB_PR_HS_SINGLE_TT:
707 		debug("Single TT\n");
708 		break;
709 	case USB_HUB_PR_HS_MULTI_TT:
710 		ret = usb_set_interface(dev, 0, 1);
711 		if (ret == 0) {
712 			debug("TT per port\n");
713 			hub->tt.multi = true;
714 		} else {
715 			debug("Using single TT (err %d)\n", ret);
716 		}
717 		break;
718 	case USB_HUB_PR_SS:
719 		/* USB 3.0 hubs don't have a TT */
720 		break;
721 	default:
722 		debug("Unrecognized hub protocol %d\n",
723 		      dev->descriptor.bDeviceProtocol);
724 		break;
725 	}
726 
727 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
728 	switch (hubCharacteristics & HUB_CHAR_TTTT) {
729 	case HUB_TTTT_8_BITS:
730 		if (dev->descriptor.bDeviceProtocol != 0) {
731 			hub->tt.think_time = 666;
732 			debug("TT requires at most %d FS bit times (%d ns)\n",
733 			      8, hub->tt.think_time);
734 		}
735 		break;
736 	case HUB_TTTT_16_BITS:
737 		hub->tt.think_time = 666 * 2;
738 		debug("TT requires at most %d FS bit times (%d ns)\n",
739 		      16, hub->tt.think_time);
740 		break;
741 	case HUB_TTTT_24_BITS:
742 		hub->tt.think_time = 666 * 3;
743 		debug("TT requires at most %d FS bit times (%d ns)\n",
744 		      24, hub->tt.think_time);
745 		break;
746 	case HUB_TTTT_32_BITS:
747 		hub->tt.think_time = 666 * 4;
748 		debug("TT requires at most %d FS bit times (%d ns)\n",
749 		      32, hub->tt.think_time);
750 		break;
751 	}
752 
753 	debug("power on to power good time: %dms\n",
754 	      descriptor->bPwrOn2PwrGood * 2);
755 	debug("hub controller current requirement: %dmA\n",
756 	      descriptor->bHubContrCurrent);
757 
758 	for (i = 0; i < dev->maxchild; i++)
759 		debug("port %d is%s removable\n", i + 1,
760 		      hub->desc.u.hs.DeviceRemovable[(i + 1) / 8] & \
761 		      (1 << ((i + 1) % 8)) ? " not" : "");
762 
763 	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
764 		debug("usb_hub_configure: failed to get Status - " \
765 		      "too long: %d\n", descriptor->bLength);
766 		return -EFBIG;
767 	}
768 
769 	ret = usb_get_hub_status(dev, buffer);
770 	if (ret < 0) {
771 		debug("usb_hub_configure: failed to get Status %lX\n",
772 		      dev->status);
773 		return ret;
774 	}
775 
776 #ifdef DEBUG
777 	hubsts = (struct usb_hub_status *)buffer;
778 #endif
779 
780 	debug("get_hub_status returned status %X, change %X\n",
781 	      le16_to_cpu(hubsts->wHubStatus),
782 	      le16_to_cpu(hubsts->wHubChange));
783 	debug("local power source is %s\n",
784 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
785 	      "lost (inactive)" : "good");
786 	debug("%sover-current condition exists\n",
787 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
788 	      "" : "no ");
789 
790 #ifdef CONFIG_DM_USB
791 	/*
792 	 * Update USB host controller's internal representation of this hub
793 	 * after the hub descriptor is fetched.
794 	 */
795 	ret = usb_update_hub_device(dev);
796 	if (ret < 0 && ret != -ENOSYS) {
797 		debug("%s: failed to update hub device for HCD (%x)\n",
798 		      __func__, ret);
799 		return ret;
800 	}
801 
802 	/*
803 	 * A maximum of seven tiers are allowed in a USB topology, and the
804 	 * root hub occupies the first tier. The last tier ends with a normal
805 	 * USB device. USB 3.0 hubs use a 20-bit field called 'route string'
806 	 * to route packets to the designated downstream port. The hub uses a
807 	 * hub depth value multiplied by four as an offset into the 'route
808 	 * string' to locate the bits it uses to determine the downstream
809 	 * port number.
810 	 */
811 	if (usb_hub_is_root_hub(dev->dev)) {
812 		hub->hub_depth = -1;
813 	} else {
814 		struct udevice *hdev;
815 		int depth = 0;
816 
817 		hdev = dev->dev->parent;
818 		while (!usb_hub_is_root_hub(hdev)) {
819 			depth++;
820 			hdev = hdev->parent;
821 		}
822 
823 		hub->hub_depth = depth;
824 
825 		if (usb_hub_is_superspeed(dev)) {
826 			debug("set hub (%p) depth to %d\n", dev, depth);
827 			/*
828 			 * This request sets the value that the hub uses to
829 			 * determine the index into the 'route string index'
830 			 * for this hub.
831 			 */
832 			ret = usb_set_hub_depth(dev, depth);
833 			if (ret < 0) {
834 				debug("%s: failed to set hub depth (%lX)\n",
835 				      __func__, dev->status);
836 				return ret;
837 			}
838 		}
839 	}
840 #endif
841 
842 	usb_hub_power_on(hub);
843 
844 	/*
845 	 * Reset any devices that may be in a bad state when applying
846 	 * the power.  This is a __weak function.  Resetting of the devices
847 	 * should occur in the board file of the device.
848 	 */
849 	for (i = 0; i < dev->maxchild; i++)
850 		usb_hub_reset_devices(i + 1);
851 
852 	/*
853 	 * Only add the connected USB devices, including potential hubs,
854 	 * to a scanning list. This list will get scanned and devices that
855 	 * are detected (either via port connected or via port timeout)
856 	 * will get removed from this list. Scanning of the devices on this
857 	 * list will continue until all devices are removed.
858 	 */
859 	for (i = 0; i < dev->maxchild; i++) {
860 		struct usb_device_scan *usb_scan;
861 
862 		usb_scan = calloc(1, sizeof(*usb_scan));
863 		if (!usb_scan) {
864 			printf("Can't allocate memory for USB device!\n");
865 			return -ENOMEM;
866 		}
867 		usb_scan->dev = dev;
868 		usb_scan->hub = hub;
869 		usb_scan->port = i;
870 		list_add_tail(&usb_scan->list, &usb_scan_list);
871 	}
872 
873 	/*
874 	 * And now call the scanning code which loops over the generated list
875 	 */
876 	ret = usb_device_list_scan();
877 
878 	return ret;
879 }
880 
881 static int usb_hub_check(struct usb_device *dev, int ifnum)
882 {
883 	struct usb_interface *iface;
884 	struct usb_endpoint_descriptor *ep = NULL;
885 
886 	iface = &dev->config.if_desc[ifnum];
887 	/* Is it a hub? */
888 	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
889 		goto err;
890 	/* Some hubs have a subclass of 1, which AFAICT according to the */
891 	/*  specs is not defined, but it works */
892 	if ((iface->desc.bInterfaceSubClass != 0) &&
893 	    (iface->desc.bInterfaceSubClass != 1))
894 		goto err;
895 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
896 	if (iface->desc.bNumEndpoints != 1)
897 		goto err;
898 	ep = &iface->ep_desc[0];
899 	/* Output endpoint? Curiousier and curiousier.. */
900 	if (!(ep->bEndpointAddress & USB_DIR_IN))
901 		goto err;
902 	/* If it's not an interrupt endpoint, we'd better punt! */
903 	if ((ep->bmAttributes & 3) != 3)
904 		goto err;
905 	/* We found a hub */
906 	debug("USB hub found\n");
907 	return 0;
908 
909 err:
910 	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
911 	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
912 	      iface->desc.bNumEndpoints);
913 	if (ep) {
914 		debug("   bEndpointAddress=%#x, bmAttributes=%d",
915 		      ep->bEndpointAddress, ep->bmAttributes);
916 	}
917 
918 	return -ENOENT;
919 }
920 
921 int usb_hub_probe(struct usb_device *dev, int ifnum)
922 {
923 	int ret;
924 
925 	ret = usb_hub_check(dev, ifnum);
926 	if (ret)
927 		return 0;
928 	ret = usb_hub_configure(dev);
929 	return ret;
930 }
931 
932 #ifdef CONFIG_DM_USB
933 int usb_hub_scan(struct udevice *hub)
934 {
935 	struct usb_device *udev = dev_get_parent_priv(hub);
936 
937 	return usb_hub_configure(udev);
938 }
939 
940 static int usb_hub_post_probe(struct udevice *dev)
941 {
942 	debug("%s\n", __func__);
943 	return usb_hub_scan(dev);
944 }
945 
946 static const struct udevice_id usb_hub_ids[] = {
947 	{ .compatible = "usb-hub" },
948 	{ }
949 };
950 
951 U_BOOT_DRIVER(usb_generic_hub) = {
952 	.name	= "usb_hub",
953 	.id	= UCLASS_USB_HUB,
954 	.of_match = usb_hub_ids,
955 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
956 };
957 
958 UCLASS_DRIVER(usb_hub) = {
959 	.id		= UCLASS_USB_HUB,
960 	.name		= "usb_hub",
961 	.post_bind	= dm_scan_fdt_dev,
962 	.post_probe	= usb_hub_post_probe,
963 	.child_pre_probe	= usb_child_pre_probe,
964 	.per_child_auto_alloc_size = sizeof(struct usb_device),
965 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
966 	.per_device_auto_alloc_size = sizeof(struct usb_hub_device),
967 };
968 
969 static const struct usb_device_id hub_id_table[] = {
970 	{
971 		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
972 		.bDeviceClass = USB_CLASS_HUB
973 	},
974 	{ }	/* Terminating entry */
975 };
976 
977 U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);
978 
979 #endif
980