xref: /rk3399_rockchip-uboot/common/usb_hub.c (revision a199a7244899f6385035459cbc62409bd9bbcc23)
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 static int usb_get_hub_descriptor(struct usb_device *dev, void *data, int size)
71 {
72 	unsigned short dtype = USB_DT_HUB;
73 
74 	if (usb_hub_is_superspeed(dev))
75 		dtype = USB_DT_SS_HUB;
76 
77 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
78 		USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
79 		dtype << 8, 0, data, size, USB_CNTL_TIMEOUT);
80 }
81 
82 static int usb_clear_port_feature(struct usb_device *dev, int port, int feature)
83 {
84 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
85 				USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature,
86 				port, NULL, 0, USB_CNTL_TIMEOUT);
87 }
88 
89 static int usb_set_port_feature(struct usb_device *dev, int port, int feature)
90 {
91 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
92 				USB_REQ_SET_FEATURE, USB_RT_PORT, feature,
93 				port, NULL, 0, USB_CNTL_TIMEOUT);
94 }
95 
96 static int usb_get_hub_status(struct usb_device *dev, void *data)
97 {
98 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
99 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
100 			data, sizeof(struct usb_hub_status), USB_CNTL_TIMEOUT);
101 }
102 
103 int usb_get_port_status(struct usb_device *dev, int port, void *data)
104 {
105 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
106 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port,
107 			data, sizeof(struct usb_port_status), USB_CNTL_TIMEOUT);
108 }
109 
110 
111 static void usb_hub_power_on(struct usb_hub_device *hub)
112 {
113 	int i;
114 	struct usb_device *dev;
115 	unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
116 	const char *env;
117 
118 	dev = hub->pusb_dev;
119 
120 	debug("enabling power on all ports\n");
121 	for (i = 0; i < dev->maxchild; i++) {
122 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
123 		debug("port %d returns %lX\n", i + 1, dev->status);
124 	}
125 
126 #ifdef CONFIG_SANDBOX
127 	/*
128 	 * Don't set timeout / delay values here. This results
129 	 * in these values still being reset to 0.
130 	 */
131 	if (state_get_skip_delays())
132 		return;
133 #endif
134 
135 	/*
136 	 * Wait for power to become stable,
137 	 * plus spec-defined max time for device to connect
138 	 * but allow this time to be increased via env variable as some
139 	 * devices break the spec and require longer warm-up times
140 	 */
141 	env = getenv("usb_pgood_delay");
142 	if (env)
143 		pgood_delay = max(pgood_delay,
144 			          (unsigned)simple_strtol(env, NULL, 0));
145 	debug("pgood_delay=%dms\n", pgood_delay);
146 
147 	/*
148 	 * Do a minimum delay of the larger value of 100ms or pgood_delay
149 	 * so that the power can stablize before the devices are queried
150 	 */
151 	hub->query_delay = get_timer(0) + max(100, (int)pgood_delay);
152 
153 	/*
154 	 * Record the power-on timeout here. The max. delay (timeout)
155 	 * will be done based on this value in the USB port loop in
156 	 * usb_hub_configure() later.
157 	 */
158 	hub->connect_timeout = hub->query_delay + 1000;
159 	debug("devnum=%d poweron: query_delay=%d connect_timeout=%d\n",
160 	      dev->devnum, max(100, (int)pgood_delay),
161 	      max(100, (int)pgood_delay) + 1000);
162 }
163 
164 #ifndef CONFIG_DM_USB
165 static struct usb_hub_device hub_dev[USB_MAX_HUB];
166 static int usb_hub_index;
167 
168 void usb_hub_reset(void)
169 {
170 	usb_hub_index = 0;
171 
172 	/* Zero out global hub_dev in case its re-used again */
173 	memset(hub_dev, 0, sizeof(hub_dev));
174 }
175 
176 static struct usb_hub_device *usb_hub_allocate(void)
177 {
178 	if (usb_hub_index < USB_MAX_HUB)
179 		return &hub_dev[usb_hub_index++];
180 
181 	printf("ERROR: USB_MAX_HUB (%d) reached\n", USB_MAX_HUB);
182 	return NULL;
183 }
184 #endif
185 
186 #define MAX_TRIES 5
187 
188 static inline char *portspeed(int portstatus)
189 {
190 	char *speed_str;
191 
192 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
193 	case USB_PORT_STAT_SUPER_SPEED:
194 		speed_str = "5 Gb/s";
195 		break;
196 	case USB_PORT_STAT_HIGH_SPEED:
197 		speed_str = "480 Mb/s";
198 		break;
199 	case USB_PORT_STAT_LOW_SPEED:
200 		speed_str = "1.5 Mb/s";
201 		break;
202 	default:
203 		speed_str = "12 Mb/s";
204 		break;
205 	}
206 
207 	return speed_str;
208 }
209 
210 /**
211  * usb_hub_port_reset() - reset a port given its usb_device pointer
212  *
213  * Reset a hub port and see if a device is present on that port, providing
214  * sufficient time for it to show itself. The port status is returned.
215  *
216  * @dev:	USB device to reset
217  * @port:	Port number to reset (note ports are numbered from 0 here)
218  * @portstat:	Returns port status
219  */
220 static int usb_hub_port_reset(struct usb_device *dev, int port,
221 			      unsigned short *portstat)
222 {
223 	int err, tries;
224 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
225 	unsigned short portstatus, portchange;
226 	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
227 
228 #ifdef CONFIG_DM_USB
229 	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
230 	      port + 1);
231 #else
232 	debug("%s: resetting port %d...\n", __func__, port + 1);
233 #endif
234 	for (tries = 0; tries < MAX_TRIES; tries++) {
235 		err = usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
236 		if (err < 0)
237 			return err;
238 
239 		mdelay(delay);
240 
241 		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
242 			debug("get_port_status failed status %lX\n",
243 			      dev->status);
244 			return -1;
245 		}
246 		portstatus = le16_to_cpu(portsts->wPortStatus);
247 		portchange = le16_to_cpu(portsts->wPortChange);
248 
249 		debug("portstatus %x, change %x, %s\n", portstatus, portchange,
250 							portspeed(portstatus));
251 
252 		debug("STAT_C_CONNECTION = %d STAT_CONNECTION = %d" \
253 		      "  USB_PORT_STAT_ENABLE %d\n",
254 		      (portchange & USB_PORT_STAT_C_CONNECTION) ? 1 : 0,
255 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
256 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
257 
258 		/*
259 		 * Perhaps we should check for the following here:
260 		 * - C_CONNECTION hasn't been set.
261 		 * - CONNECTION is still set.
262 		 *
263 		 * Doing so would ensure that the device is still connected
264 		 * to the bus, and hasn't been unplugged or replaced while the
265 		 * USB bus reset was going on.
266 		 *
267 		 * However, if we do that, then (at least) a San Disk Ultra
268 		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
269 		 * Tegra Jetson TK1 board. For some reason, the device appears
270 		 * to briefly drop off the bus when this second bus reset is
271 		 * executed, yet if we retry this loop, it'll eventually come
272 		 * back after another reset or two.
273 		 */
274 
275 		if (portstatus & USB_PORT_STAT_ENABLE)
276 			break;
277 
278 		/* Switch to long reset delay for the next round */
279 		delay = HUB_LONG_RESET_TIME;
280 	}
281 
282 	if (tries == MAX_TRIES) {
283 		debug("Cannot enable port %i after %i retries, " \
284 		      "disabling port.\n", port + 1, MAX_TRIES);
285 		debug("Maybe the USB cable is bad?\n");
286 		return -1;
287 	}
288 
289 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_RESET);
290 	*portstat = portstatus;
291 	return 0;
292 }
293 
294 int usb_hub_port_connect_change(struct usb_device *dev, int port)
295 {
296 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
297 	unsigned short portstatus;
298 	int ret, speed;
299 
300 	/* Check status */
301 	ret = usb_get_port_status(dev, port + 1, portsts);
302 	if (ret < 0) {
303 		debug("get_port_status failed\n");
304 		return ret;
305 	}
306 
307 	portstatus = le16_to_cpu(portsts->wPortStatus);
308 	debug("portstatus %x, change %x, %s\n",
309 	      portstatus,
310 	      le16_to_cpu(portsts->wPortChange),
311 	      portspeed(portstatus));
312 
313 	/* Clear the connection change status */
314 	usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_C_CONNECTION);
315 
316 	/* Disconnect any existing devices under this port */
317 	if (((!(portstatus & USB_PORT_STAT_CONNECTION)) &&
318 	     (!(portstatus & USB_PORT_STAT_ENABLE))) ||
319 	    usb_device_has_child_on_port(dev, port)) {
320 		debug("usb_disconnect(&hub->children[port]);\n");
321 		/* Return now if nothing is connected */
322 		if (!(portstatus & USB_PORT_STAT_CONNECTION))
323 			return -ENOTCONN;
324 	}
325 
326 	/* Reset the port */
327 	ret = usb_hub_port_reset(dev, port, &portstatus);
328 	if (ret < 0) {
329 		if (ret != -ENXIO)
330 			printf("cannot reset port %i!?\n", port + 1);
331 		return ret;
332 	}
333 
334 	switch (portstatus & USB_PORT_STAT_SPEED_MASK) {
335 	case USB_PORT_STAT_SUPER_SPEED:
336 		speed = USB_SPEED_SUPER;
337 		break;
338 	case USB_PORT_STAT_HIGH_SPEED:
339 		speed = USB_SPEED_HIGH;
340 		break;
341 	case USB_PORT_STAT_LOW_SPEED:
342 		speed = USB_SPEED_LOW;
343 		break;
344 	default:
345 		speed = USB_SPEED_FULL;
346 		break;
347 	}
348 
349 #ifdef CONFIG_DM_USB
350 	struct udevice *child;
351 
352 	ret = usb_scan_device(dev->dev, port + 1, speed, &child);
353 #else
354 	struct usb_device *usb;
355 
356 	ret = usb_alloc_new_device(dev->controller, &usb);
357 	if (ret) {
358 		printf("cannot create new device: ret=%d", ret);
359 		return ret;
360 	}
361 
362 	dev->children[port] = usb;
363 	usb->speed = speed;
364 	usb->parent = dev;
365 	usb->portnr = port + 1;
366 	/* Run it through the hoops (find a driver, etc) */
367 	ret = usb_new_device(usb);
368 	if (ret < 0) {
369 		/* Woops, disable the port */
370 		usb_free_device(dev->controller);
371 		dev->children[port] = NULL;
372 	}
373 #endif
374 	if (ret < 0) {
375 		debug("hub: disabling port %d\n", port + 1);
376 		usb_clear_port_feature(dev, port + 1, USB_PORT_FEAT_ENABLE);
377 	}
378 
379 	return ret;
380 }
381 
382 static int usb_scan_port(struct usb_device_scan *usb_scan)
383 {
384 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
385 	unsigned short portstatus;
386 	unsigned short portchange;
387 	struct usb_device *dev;
388 	struct usb_hub_device *hub;
389 	int ret = 0;
390 	int i;
391 
392 	dev = usb_scan->dev;
393 	hub = usb_scan->hub;
394 	i = usb_scan->port;
395 
396 	/*
397 	 * Don't talk to the device before the query delay is expired.
398 	 * This is needed for voltages to stabalize.
399 	 */
400 	if (get_timer(0) < hub->query_delay)
401 		return 0;
402 
403 	ret = usb_get_port_status(dev, i + 1, portsts);
404 	if (ret < 0) {
405 		debug("get_port_status failed\n");
406 		if (get_timer(0) >= hub->connect_timeout) {
407 			debug("devnum=%d port=%d: timeout\n",
408 			      dev->devnum, i + 1);
409 			/* Remove this device from scanning list */
410 			list_del(&usb_scan->list);
411 			free(usb_scan);
412 			return 0;
413 		}
414 		return 0;
415 	}
416 
417 	portstatus = le16_to_cpu(portsts->wPortStatus);
418 	portchange = le16_to_cpu(portsts->wPortChange);
419 	debug("Port %d Status %X Change %X\n", i + 1, portstatus, portchange);
420 
421 	/*
422 	 * No connection change happened, wait a bit more.
423 	 *
424 	 * For some situation, the hub reports no connection change but a
425 	 * device is connected to the port (eg: CCS bit is set but CSC is not
426 	 * in the PORTSC register of a root hub), ignore such case.
427 	 */
428 	if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
429 	    !(portstatus & USB_PORT_STAT_CONNECTION)) {
430 		if (get_timer(0) >= hub->connect_timeout) {
431 			debug("devnum=%d port=%d: timeout\n",
432 			      dev->devnum, i + 1);
433 			/* Remove this device from scanning list */
434 			list_del(&usb_scan->list);
435 			free(usb_scan);
436 			return 0;
437 		}
438 		return 0;
439 	}
440 
441 	/* A new USB device is ready at this point */
442 	debug("devnum=%d port=%d: USB dev found\n", dev->devnum, i + 1);
443 
444 	usb_hub_port_connect_change(dev, i);
445 
446 	if (portchange & USB_PORT_STAT_C_ENABLE) {
447 		debug("port %d enable change, status %x\n", i + 1, portstatus);
448 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_ENABLE);
449 		/*
450 		 * The following hack causes a ghost device problem
451 		 * to Faraday EHCI
452 		 */
453 #ifndef CONFIG_USB_EHCI_FARADAY
454 		/*
455 		 * EM interference sometimes causes bad shielded USB
456 		 * devices to be shutdown by the hub, this hack enables
457 		 * them again. Works at least with mouse driver
458 		 */
459 		if (!(portstatus & USB_PORT_STAT_ENABLE) &&
460 		    (portstatus & USB_PORT_STAT_CONNECTION) &&
461 		    usb_device_has_child_on_port(dev, i)) {
462 			debug("already running port %i disabled by hub (EMI?), re-enabling...\n",
463 			      i + 1);
464 			usb_hub_port_connect_change(dev, i);
465 		}
466 #endif
467 	}
468 
469 	if (portstatus & USB_PORT_STAT_SUSPEND) {
470 		debug("port %d suspend change\n", i + 1);
471 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_SUSPEND);
472 	}
473 
474 	if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
475 		debug("port %d over-current change\n", i + 1);
476 		usb_clear_port_feature(dev, i + 1,
477 				       USB_PORT_FEAT_C_OVER_CURRENT);
478 		/* Only power-on this one port */
479 		usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
480 		hub->overcurrent_count[i]++;
481 
482 		/*
483 		 * If the max-scan-count is not reached, return without removing
484 		 * the device from scan-list. This will re-issue a new scan.
485 		 */
486 		if (hub->overcurrent_count[i] <=
487 		    PORT_OVERCURRENT_MAX_SCAN_COUNT)
488 			return 0;
489 
490 		/* Otherwise the device will get removed */
491 		printf("Port %d over-current occurred %d times\n", i + 1,
492 		       hub->overcurrent_count[i]);
493 	}
494 
495 	if (portchange & USB_PORT_STAT_C_RESET) {
496 		debug("port %d reset change\n", i + 1);
497 		usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_C_RESET);
498 	}
499 
500 	/*
501 	 * We're done with this device, so let's remove this device from
502 	 * scanning list
503 	 */
504 	list_del(&usb_scan->list);
505 	free(usb_scan);
506 
507 	return 0;
508 }
509 
510 static int usb_device_list_scan(void)
511 {
512 	struct usb_device_scan *usb_scan;
513 	struct usb_device_scan *tmp;
514 	static int running;
515 	int ret = 0;
516 
517 	/* Only run this loop once for each controller */
518 	if (running)
519 		return 0;
520 
521 	running = 1;
522 
523 	while (1) {
524 		/* We're done, once the list is empty again */
525 		if (list_empty(&usb_scan_list))
526 			goto out;
527 
528 		list_for_each_entry_safe(usb_scan, tmp, &usb_scan_list, list) {
529 			int ret;
530 
531 			/* Scan this port */
532 			ret = usb_scan_port(usb_scan);
533 			if (ret)
534 				goto out;
535 		}
536 	}
537 
538 out:
539 	/*
540 	 * This USB controller has finished scanning all its connected
541 	 * USB devices. Set "running" back to 0, so that other USB controllers
542 	 * will scan their devices too.
543 	 */
544 	running = 0;
545 
546 	return ret;
547 }
548 
549 static struct usb_hub_device *usb_get_hub_device(struct usb_device *dev)
550 {
551 	struct usb_hub_device *hub;
552 
553 #ifndef CONFIG_DM_USB
554 	/* "allocate" Hub device */
555 	hub = usb_hub_allocate();
556 #else
557 	hub = dev_get_uclass_priv(dev->dev);
558 #endif
559 
560 	return hub;
561 }
562 
563 static int usb_hub_configure(struct usb_device *dev)
564 {
565 	int i, length;
566 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
567 	unsigned char *bitmap;
568 	short hubCharacteristics;
569 	struct usb_hub_descriptor *descriptor;
570 	struct usb_hub_device *hub;
571 	__maybe_unused struct usb_hub_status *hubsts;
572 	int ret;
573 
574 	hub = usb_get_hub_device(dev);
575 	if (hub == NULL)
576 		return -ENOMEM;
577 	hub->pusb_dev = dev;
578 
579 	/* Get the the hub descriptor */
580 	ret = usb_get_hub_descriptor(dev, buffer, 4);
581 	if (ret < 0) {
582 		debug("usb_hub_configure: failed to get hub " \
583 		      "descriptor, giving up %lX\n", dev->status);
584 		return ret;
585 	}
586 	descriptor = (struct usb_hub_descriptor *)buffer;
587 
588 	length = min_t(int, descriptor->bLength,
589 		       sizeof(struct usb_hub_descriptor));
590 
591 	ret = usb_get_hub_descriptor(dev, buffer, length);
592 	if (ret < 0) {
593 		debug("usb_hub_configure: failed to get hub " \
594 		      "descriptor 2nd giving up %lX\n", dev->status);
595 		return ret;
596 	}
597 	memcpy((unsigned char *)&hub->desc, buffer, length);
598 	/* adjust 16bit values */
599 	put_unaligned(le16_to_cpu(get_unaligned(
600 			&descriptor->wHubCharacteristics)),
601 			&hub->desc.wHubCharacteristics);
602 	/* set the bitmap */
603 	bitmap = (unsigned char *)&hub->desc.u.hs.DeviceRemovable[0];
604 	/* devices not removable by default */
605 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8);
606 	bitmap = (unsigned char *)&hub->desc.u.hs.PortPowerCtrlMask[0];
607 	memset(bitmap, 0xff, (USB_MAXCHILDREN+1+7)/8); /* PowerMask = 1B */
608 
609 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
610 		hub->desc.u.hs.DeviceRemovable[i] =
611 			descriptor->u.hs.DeviceRemovable[i];
612 
613 	for (i = 0; i < ((hub->desc.bNbrPorts + 1 + 7)/8); i++)
614 		hub->desc.u.hs.PortPowerCtrlMask[i] =
615 			descriptor->u.hs.PortPowerCtrlMask[i];
616 
617 	dev->maxchild = descriptor->bNbrPorts;
618 	debug("%d ports detected\n", dev->maxchild);
619 
620 	hubCharacteristics = get_unaligned(&hub->desc.wHubCharacteristics);
621 	switch (hubCharacteristics & HUB_CHAR_LPSM) {
622 	case 0x00:
623 		debug("ganged power switching\n");
624 		break;
625 	case 0x01:
626 		debug("individual port power switching\n");
627 		break;
628 	case 0x02:
629 	case 0x03:
630 		debug("unknown reserved power switching mode\n");
631 		break;
632 	}
633 
634 	if (hubCharacteristics & HUB_CHAR_COMPOUND)
635 		debug("part of a compound device\n");
636 	else
637 		debug("standalone hub\n");
638 
639 	switch (hubCharacteristics & HUB_CHAR_OCPM) {
640 	case 0x00:
641 		debug("global over-current protection\n");
642 		break;
643 	case 0x08:
644 		debug("individual port over-current protection\n");
645 		break;
646 	case 0x10:
647 	case 0x18:
648 		debug("no over-current protection\n");
649 		break;
650 	}
651 
652 	debug("power on to power good time: %dms\n",
653 	      descriptor->bPwrOn2PwrGood * 2);
654 	debug("hub controller current requirement: %dmA\n",
655 	      descriptor->bHubContrCurrent);
656 
657 	for (i = 0; i < dev->maxchild; i++)
658 		debug("port %d is%s removable\n", i + 1,
659 		      hub->desc.u.hs.DeviceRemovable[(i + 1) / 8] & \
660 		      (1 << ((i + 1) % 8)) ? " not" : "");
661 
662 	if (sizeof(struct usb_hub_status) > USB_BUFSIZ) {
663 		debug("usb_hub_configure: failed to get Status - " \
664 		      "too long: %d\n", descriptor->bLength);
665 		return -EFBIG;
666 	}
667 
668 	ret = usb_get_hub_status(dev, buffer);
669 	if (ret < 0) {
670 		debug("usb_hub_configure: failed to get Status %lX\n",
671 		      dev->status);
672 		return ret;
673 	}
674 
675 #ifdef DEBUG
676 	hubsts = (struct usb_hub_status *)buffer;
677 #endif
678 
679 	debug("get_hub_status returned status %X, change %X\n",
680 	      le16_to_cpu(hubsts->wHubStatus),
681 	      le16_to_cpu(hubsts->wHubChange));
682 	debug("local power source is %s\n",
683 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_LOCAL_POWER) ? \
684 	      "lost (inactive)" : "good");
685 	debug("%sover-current condition exists\n",
686 	      (le16_to_cpu(hubsts->wHubStatus) & HUB_STATUS_OVERCURRENT) ? \
687 	      "" : "no ");
688 	usb_hub_power_on(hub);
689 
690 	/*
691 	 * Reset any devices that may be in a bad state when applying
692 	 * the power.  This is a __weak function.  Resetting of the devices
693 	 * should occur in the board file of the device.
694 	 */
695 	for (i = 0; i < dev->maxchild; i++)
696 		usb_hub_reset_devices(i + 1);
697 
698 	/*
699 	 * Only add the connected USB devices, including potential hubs,
700 	 * to a scanning list. This list will get scanned and devices that
701 	 * are detected (either via port connected or via port timeout)
702 	 * will get removed from this list. Scanning of the devices on this
703 	 * list will continue until all devices are removed.
704 	 */
705 	for (i = 0; i < dev->maxchild; i++) {
706 		struct usb_device_scan *usb_scan;
707 
708 		usb_scan = calloc(1, sizeof(*usb_scan));
709 		if (!usb_scan) {
710 			printf("Can't allocate memory for USB device!\n");
711 			return -ENOMEM;
712 		}
713 		usb_scan->dev = dev;
714 		usb_scan->hub = hub;
715 		usb_scan->port = i;
716 		list_add_tail(&usb_scan->list, &usb_scan_list);
717 	}
718 
719 	/*
720 	 * And now call the scanning code which loops over the generated list
721 	 */
722 	ret = usb_device_list_scan();
723 
724 	return ret;
725 }
726 
727 static int usb_hub_check(struct usb_device *dev, int ifnum)
728 {
729 	struct usb_interface *iface;
730 	struct usb_endpoint_descriptor *ep = NULL;
731 
732 	iface = &dev->config.if_desc[ifnum];
733 	/* Is it a hub? */
734 	if (iface->desc.bInterfaceClass != USB_CLASS_HUB)
735 		goto err;
736 	/* Some hubs have a subclass of 1, which AFAICT according to the */
737 	/*  specs is not defined, but it works */
738 	if ((iface->desc.bInterfaceSubClass != 0) &&
739 	    (iface->desc.bInterfaceSubClass != 1))
740 		goto err;
741 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
742 	if (iface->desc.bNumEndpoints != 1)
743 		goto err;
744 	ep = &iface->ep_desc[0];
745 	/* Output endpoint? Curiousier and curiousier.. */
746 	if (!(ep->bEndpointAddress & USB_DIR_IN))
747 		goto err;
748 	/* If it's not an interrupt endpoint, we'd better punt! */
749 	if ((ep->bmAttributes & 3) != 3)
750 		goto err;
751 	/* We found a hub */
752 	debug("USB hub found\n");
753 	return 0;
754 
755 err:
756 	debug("USB hub not found: bInterfaceClass=%d, bInterfaceSubClass=%d, bNumEndpoints=%d\n",
757 	      iface->desc.bInterfaceClass, iface->desc.bInterfaceSubClass,
758 	      iface->desc.bNumEndpoints);
759 	if (ep) {
760 		debug("   bEndpointAddress=%#x, bmAttributes=%d",
761 		      ep->bEndpointAddress, ep->bmAttributes);
762 	}
763 
764 	return -ENOENT;
765 }
766 
767 int usb_hub_probe(struct usb_device *dev, int ifnum)
768 {
769 	int ret;
770 
771 	ret = usb_hub_check(dev, ifnum);
772 	if (ret)
773 		return 0;
774 	ret = usb_hub_configure(dev);
775 	return ret;
776 }
777 
778 #ifdef CONFIG_DM_USB
779 int usb_hub_scan(struct udevice *hub)
780 {
781 	struct usb_device *udev = dev_get_parent_priv(hub);
782 
783 	return usb_hub_configure(udev);
784 }
785 
786 static int usb_hub_post_probe(struct udevice *dev)
787 {
788 	debug("%s\n", __func__);
789 	return usb_hub_scan(dev);
790 }
791 
792 static const struct udevice_id usb_hub_ids[] = {
793 	{ .compatible = "usb-hub" },
794 	{ }
795 };
796 
797 U_BOOT_DRIVER(usb_generic_hub) = {
798 	.name	= "usb_hub",
799 	.id	= UCLASS_USB_HUB,
800 	.of_match = usb_hub_ids,
801 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
802 };
803 
804 UCLASS_DRIVER(usb_hub) = {
805 	.id		= UCLASS_USB_HUB,
806 	.name		= "usb_hub",
807 	.post_bind	= dm_scan_fdt_dev,
808 	.post_probe	= usb_hub_post_probe,
809 	.child_pre_probe	= usb_child_pre_probe,
810 	.per_child_auto_alloc_size = sizeof(struct usb_device),
811 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
812 	.per_device_auto_alloc_size = sizeof(struct usb_hub_device),
813 };
814 
815 static const struct usb_device_id hub_id_table[] = {
816 	{
817 		.match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
818 		.bDeviceClass = USB_CLASS_HUB
819 	},
820 	{ }	/* Terminating entry */
821 };
822 
823 U_BOOT_USB_DEVICE(usb_generic_hub, hub_id_table);
824 
825 #endif
826