xref: /linux/drivers/phy/tegra/xusb.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa) 
1 /*
2  * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/io.h>
16 #include <linux/mailbox_client.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/phy/phy.h>
21 #include <linux/phy/tegra/xusb.h>
22 #include <linux/platform_device.h>
23 #include <linux/regulator/consumer.h>
24 #include <linux/reset.h>
25 #include <linux/slab.h>
26 #include <linux/workqueue.h>
27 
28 #include <soc/tegra/fuse.h>
29 
30 #include "xusb.h"
31 
32 static struct phy *tegra_xusb_pad_of_xlate(struct device *dev,
33 					   struct of_phandle_args *args)
34 {
35 	struct tegra_xusb_pad *pad = dev_get_drvdata(dev);
36 	struct phy *phy = NULL;
37 	unsigned int i;
38 
39 	if (args->args_count != 0)
40 		return ERR_PTR(-EINVAL);
41 
42 	for (i = 0; i < pad->soc->num_lanes; i++) {
43 		if (!pad->lanes[i])
44 			continue;
45 
46 		if (pad->lanes[i]->dev.of_node == args->np) {
47 			phy = pad->lanes[i];
48 			break;
49 		}
50 	}
51 
52 	if (phy == NULL)
53 		phy = ERR_PTR(-ENODEV);
54 
55 	return phy;
56 }
57 
58 static const struct of_device_id tegra_xusb_padctl_of_match[] = {
59 #if defined(CONFIG_ARCH_TEGRA_124_SOC) || defined(CONFIG_ARCH_TEGRA_132_SOC)
60 	{
61 		.compatible = "nvidia,tegra124-xusb-padctl",
62 		.data = &tegra124_xusb_padctl_soc,
63 	},
64 #endif
65 #if defined(CONFIG_ARCH_TEGRA_210_SOC)
66 	{
67 		.compatible = "nvidia,tegra210-xusb-padctl",
68 		.data = &tegra210_xusb_padctl_soc,
69 	},
70 #endif
71 	{ }
72 };
73 MODULE_DEVICE_TABLE(of, tegra_xusb_padctl_of_match);
74 
75 static struct device_node *
76 tegra_xusb_find_pad_node(struct tegra_xusb_padctl *padctl, const char *name)
77 {
78 	/*
79 	 * of_find_node_by_name() drops a reference, so make sure to grab one.
80 	 */
81 	struct device_node *np = of_node_get(padctl->dev->of_node);
82 
83 	np = of_find_node_by_name(np, "pads");
84 	if (np)
85 		np = of_find_node_by_name(np, name);
86 
87 	return np;
88 }
89 
90 static struct device_node *
91 tegra_xusb_pad_find_phy_node(struct tegra_xusb_pad *pad, unsigned int index)
92 {
93 	/*
94 	 * of_find_node_by_name() drops a reference, so make sure to grab one.
95 	 */
96 	struct device_node *np = of_node_get(pad->dev.of_node);
97 
98 	np = of_find_node_by_name(np, "lanes");
99 	if (!np)
100 		return NULL;
101 
102 	return of_find_node_by_name(np, pad->soc->lanes[index].name);
103 }
104 
105 static int
106 tegra_xusb_lane_lookup_function(struct tegra_xusb_lane *lane,
107 				    const char *function)
108 {
109 	unsigned int i;
110 
111 	for (i = 0; i < lane->soc->num_funcs; i++)
112 		if (strcmp(function, lane->soc->funcs[i]) == 0)
113 			return i;
114 
115 	return -EINVAL;
116 }
117 
118 int tegra_xusb_lane_parse_dt(struct tegra_xusb_lane *lane,
119 			     struct device_node *np)
120 {
121 	struct device *dev = &lane->pad->dev;
122 	const char *function;
123 	int err;
124 
125 	err = of_property_read_string(np, "nvidia,function", &function);
126 	if (err < 0)
127 		return err;
128 
129 	err = tegra_xusb_lane_lookup_function(lane, function);
130 	if (err < 0) {
131 		dev_err(dev, "invalid function \"%s\" for lane \"%s\"\n",
132 			function, np->name);
133 		return err;
134 	}
135 
136 	lane->function = err;
137 
138 	return 0;
139 }
140 
141 static void tegra_xusb_lane_destroy(struct phy *phy)
142 {
143 	if (phy) {
144 		struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
145 
146 		lane->pad->ops->remove(lane);
147 		phy_destroy(phy);
148 	}
149 }
150 
151 static void tegra_xusb_pad_release(struct device *dev)
152 {
153 	struct tegra_xusb_pad *pad = to_tegra_xusb_pad(dev);
154 
155 	pad->soc->ops->remove(pad);
156 }
157 
158 static struct device_type tegra_xusb_pad_type = {
159 	.release = tegra_xusb_pad_release,
160 };
161 
162 int tegra_xusb_pad_init(struct tegra_xusb_pad *pad,
163 			struct tegra_xusb_padctl *padctl,
164 			struct device_node *np)
165 {
166 	int err;
167 
168 	device_initialize(&pad->dev);
169 	INIT_LIST_HEAD(&pad->list);
170 	pad->dev.parent = padctl->dev;
171 	pad->dev.type = &tegra_xusb_pad_type;
172 	pad->dev.of_node = np;
173 	pad->padctl = padctl;
174 
175 	err = dev_set_name(&pad->dev, "%s", pad->soc->name);
176 	if (err < 0)
177 		goto unregister;
178 
179 	err = device_add(&pad->dev);
180 	if (err < 0)
181 		goto unregister;
182 
183 	return 0;
184 
185 unregister:
186 	device_unregister(&pad->dev);
187 	return err;
188 }
189 
190 int tegra_xusb_pad_register(struct tegra_xusb_pad *pad,
191 			    const struct phy_ops *ops)
192 {
193 	struct device_node *children;
194 	struct phy *lane;
195 	unsigned int i;
196 	int err;
197 
198 	children = of_find_node_by_name(pad->dev.of_node, "lanes");
199 	if (!children)
200 		return -ENODEV;
201 
202 	pad->lanes = devm_kcalloc(&pad->dev, pad->soc->num_lanes, sizeof(lane),
203 				  GFP_KERNEL);
204 	if (!pad->lanes) {
205 		of_node_put(children);
206 		return -ENOMEM;
207 	}
208 
209 	for (i = 0; i < pad->soc->num_lanes; i++) {
210 		struct device_node *np = tegra_xusb_pad_find_phy_node(pad, i);
211 		struct tegra_xusb_lane *lane;
212 
213 		/* skip disabled lanes */
214 		if (!np || !of_device_is_available(np)) {
215 			of_node_put(np);
216 			continue;
217 		}
218 
219 		pad->lanes[i] = phy_create(&pad->dev, np, ops);
220 		if (IS_ERR(pad->lanes[i])) {
221 			err = PTR_ERR(pad->lanes[i]);
222 			of_node_put(np);
223 			goto remove;
224 		}
225 
226 		lane = pad->ops->probe(pad, np, i);
227 		if (IS_ERR(lane)) {
228 			phy_destroy(pad->lanes[i]);
229 			err = PTR_ERR(lane);
230 			goto remove;
231 		}
232 
233 		list_add_tail(&lane->list, &pad->padctl->lanes);
234 		phy_set_drvdata(pad->lanes[i], lane);
235 	}
236 
237 	pad->provider = of_phy_provider_register_full(&pad->dev, children,
238 						      tegra_xusb_pad_of_xlate);
239 	if (IS_ERR(pad->provider)) {
240 		err = PTR_ERR(pad->provider);
241 		goto remove;
242 	}
243 
244 	return 0;
245 
246 remove:
247 	while (i--)
248 		tegra_xusb_lane_destroy(pad->lanes[i]);
249 
250 	of_node_put(children);
251 
252 	return err;
253 }
254 
255 void tegra_xusb_pad_unregister(struct tegra_xusb_pad *pad)
256 {
257 	unsigned int i = pad->soc->num_lanes;
258 
259 	of_phy_provider_unregister(pad->provider);
260 
261 	while (i--)
262 		tegra_xusb_lane_destroy(pad->lanes[i]);
263 
264 	device_unregister(&pad->dev);
265 }
266 
267 static struct tegra_xusb_pad *
268 tegra_xusb_pad_create(struct tegra_xusb_padctl *padctl,
269 		      const struct tegra_xusb_pad_soc *soc)
270 {
271 	struct tegra_xusb_pad *pad;
272 	struct device_node *np;
273 	int err;
274 
275 	np = tegra_xusb_find_pad_node(padctl, soc->name);
276 	if (!np || !of_device_is_available(np))
277 		return NULL;
278 
279 	pad = soc->ops->probe(padctl, soc, np);
280 	if (IS_ERR(pad)) {
281 		err = PTR_ERR(pad);
282 		dev_err(padctl->dev, "failed to create pad %s: %d\n",
283 			soc->name, err);
284 		return ERR_PTR(err);
285 	}
286 
287 	/* XXX move this into ->probe() to avoid string comparison */
288 	if (strcmp(soc->name, "pcie") == 0)
289 		padctl->pcie = pad;
290 
291 	if (strcmp(soc->name, "sata") == 0)
292 		padctl->sata = pad;
293 
294 	if (strcmp(soc->name, "usb2") == 0)
295 		padctl->usb2 = pad;
296 
297 	if (strcmp(soc->name, "ulpi") == 0)
298 		padctl->ulpi = pad;
299 
300 	if (strcmp(soc->name, "hsic") == 0)
301 		padctl->hsic = pad;
302 
303 	return pad;
304 }
305 
306 static void __tegra_xusb_remove_pads(struct tegra_xusb_padctl *padctl)
307 {
308 	struct tegra_xusb_pad *pad, *tmp;
309 
310 	list_for_each_entry_safe_reverse(pad, tmp, &padctl->pads, list) {
311 		list_del(&pad->list);
312 		tegra_xusb_pad_unregister(pad);
313 	}
314 }
315 
316 static void tegra_xusb_remove_pads(struct tegra_xusb_padctl *padctl)
317 {
318 	mutex_lock(&padctl->lock);
319 	__tegra_xusb_remove_pads(padctl);
320 	mutex_unlock(&padctl->lock);
321 }
322 
323 static void tegra_xusb_lane_program(struct tegra_xusb_lane *lane)
324 {
325 	struct tegra_xusb_padctl *padctl = lane->pad->padctl;
326 	const struct tegra_xusb_lane_soc *soc = lane->soc;
327 	u32 value;
328 
329 	/* choose function */
330 	value = padctl_readl(padctl, soc->offset);
331 	value &= ~(soc->mask << soc->shift);
332 	value |= lane->function << soc->shift;
333 	padctl_writel(padctl, value, soc->offset);
334 }
335 
336 static void tegra_xusb_pad_program(struct tegra_xusb_pad *pad)
337 {
338 	unsigned int i;
339 
340 	for (i = 0; i < pad->soc->num_lanes; i++) {
341 		struct tegra_xusb_lane *lane;
342 
343 		if (pad->lanes[i]) {
344 			lane = phy_get_drvdata(pad->lanes[i]);
345 			tegra_xusb_lane_program(lane);
346 		}
347 	}
348 }
349 
350 static int tegra_xusb_setup_pads(struct tegra_xusb_padctl *padctl)
351 {
352 	struct tegra_xusb_pad *pad;
353 	unsigned int i;
354 
355 	mutex_lock(&padctl->lock);
356 
357 	for (i = 0; i < padctl->soc->num_pads; i++) {
358 		const struct tegra_xusb_pad_soc *soc = padctl->soc->pads[i];
359 		int err;
360 
361 		pad = tegra_xusb_pad_create(padctl, soc);
362 		if (IS_ERR(pad)) {
363 			err = PTR_ERR(pad);
364 			dev_err(padctl->dev, "failed to create pad %s: %d\n",
365 				soc->name, err);
366 			__tegra_xusb_remove_pads(padctl);
367 			mutex_unlock(&padctl->lock);
368 			return err;
369 		}
370 
371 		if (!pad)
372 			continue;
373 
374 		list_add_tail(&pad->list, &padctl->pads);
375 	}
376 
377 	list_for_each_entry(pad, &padctl->pads, list)
378 		tegra_xusb_pad_program(pad);
379 
380 	mutex_unlock(&padctl->lock);
381 	return 0;
382 }
383 
384 static bool tegra_xusb_lane_check(struct tegra_xusb_lane *lane,
385 				  const char *function)
386 {
387 	const char *func = lane->soc->funcs[lane->function];
388 
389 	return strcmp(function, func) == 0;
390 }
391 
392 struct tegra_xusb_lane *tegra_xusb_find_lane(struct tegra_xusb_padctl *padctl,
393 					     const char *type,
394 					     unsigned int index)
395 {
396 	struct tegra_xusb_lane *lane, *hit = ERR_PTR(-ENODEV);
397 	char *name;
398 
399 	name = kasprintf(GFP_KERNEL, "%s-%u", type, index);
400 	if (!name)
401 		return ERR_PTR(-ENOMEM);
402 
403 	list_for_each_entry(lane, &padctl->lanes, list) {
404 		if (strcmp(lane->soc->name, name) == 0) {
405 			hit = lane;
406 			break;
407 		}
408 	}
409 
410 	kfree(name);
411 	return hit;
412 }
413 
414 struct tegra_xusb_lane *
415 tegra_xusb_port_find_lane(struct tegra_xusb_port *port,
416 			  const struct tegra_xusb_lane_map *map,
417 			  const char *function)
418 {
419 	struct tegra_xusb_lane *lane, *match = ERR_PTR(-ENODEV);
420 
421 	for (map = map; map->type; map++) {
422 		if (port->index != map->port)
423 			continue;
424 
425 		lane = tegra_xusb_find_lane(port->padctl, map->type,
426 					    map->index);
427 		if (IS_ERR(lane))
428 			continue;
429 
430 		if (!tegra_xusb_lane_check(lane, function))
431 			continue;
432 
433 		if (!IS_ERR(match))
434 			dev_err(&port->dev, "conflicting match: %s-%u / %s\n",
435 				map->type, map->index, match->soc->name);
436 		else
437 			match = lane;
438 	}
439 
440 	return match;
441 }
442 
443 static struct device_node *
444 tegra_xusb_find_port_node(struct tegra_xusb_padctl *padctl, const char *type,
445 			  unsigned int index)
446 {
447 	/*
448 	 * of_find_node_by_name() drops a reference, so make sure to grab one.
449 	 */
450 	struct device_node *np = of_node_get(padctl->dev->of_node);
451 
452 	np = of_find_node_by_name(np, "ports");
453 	if (np) {
454 		char *name;
455 
456 		name = kasprintf(GFP_KERNEL, "%s-%u", type, index);
457 		np = of_find_node_by_name(np, name);
458 		kfree(name);
459 	}
460 
461 	return np;
462 }
463 
464 struct tegra_xusb_port *
465 tegra_xusb_find_port(struct tegra_xusb_padctl *padctl, const char *type,
466 		     unsigned int index)
467 {
468 	struct tegra_xusb_port *port;
469 	struct device_node *np;
470 
471 	np = tegra_xusb_find_port_node(padctl, type, index);
472 	if (!np)
473 		return NULL;
474 
475 	list_for_each_entry(port, &padctl->ports, list) {
476 		if (np == port->dev.of_node) {
477 			of_node_put(np);
478 			return port;
479 		}
480 	}
481 
482 	of_node_put(np);
483 
484 	return NULL;
485 }
486 
487 struct tegra_xusb_usb2_port *
488 tegra_xusb_find_usb2_port(struct tegra_xusb_padctl *padctl, unsigned int index)
489 {
490 	struct tegra_xusb_port *port;
491 
492 	port = tegra_xusb_find_port(padctl, "usb2", index);
493 	if (port)
494 		return to_usb2_port(port);
495 
496 	return NULL;
497 }
498 
499 struct tegra_xusb_usb3_port *
500 tegra_xusb_find_usb3_port(struct tegra_xusb_padctl *padctl, unsigned int index)
501 {
502 	struct tegra_xusb_port *port;
503 
504 	port = tegra_xusb_find_port(padctl, "usb3", index);
505 	if (port)
506 		return to_usb3_port(port);
507 
508 	return NULL;
509 }
510 
511 static void tegra_xusb_port_release(struct device *dev)
512 {
513 }
514 
515 static struct device_type tegra_xusb_port_type = {
516 	.release = tegra_xusb_port_release,
517 };
518 
519 static int tegra_xusb_port_init(struct tegra_xusb_port *port,
520 				struct tegra_xusb_padctl *padctl,
521 				struct device_node *np,
522 				const char *name,
523 				unsigned int index)
524 {
525 	int err;
526 
527 	INIT_LIST_HEAD(&port->list);
528 	port->padctl = padctl;
529 	port->index = index;
530 
531 	device_initialize(&port->dev);
532 	port->dev.type = &tegra_xusb_port_type;
533 	port->dev.of_node = of_node_get(np);
534 	port->dev.parent = padctl->dev;
535 
536 	err = dev_set_name(&port->dev, "%s-%u", name, index);
537 	if (err < 0)
538 		goto unregister;
539 
540 	err = device_add(&port->dev);
541 	if (err < 0)
542 		goto unregister;
543 
544 	return 0;
545 
546 unregister:
547 	device_unregister(&port->dev);
548 	return err;
549 }
550 
551 static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
552 {
553 	device_unregister(&port->dev);
554 }
555 
556 static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
557 {
558 	struct tegra_xusb_port *port = &usb2->base;
559 	struct device_node *np = port->dev.of_node;
560 
561 	usb2->internal = of_property_read_bool(np, "nvidia,internal");
562 
563 	usb2->supply = devm_regulator_get(&port->dev, "vbus");
564 	return PTR_ERR_OR_ZERO(usb2->supply);
565 }
566 
567 static int tegra_xusb_add_usb2_port(struct tegra_xusb_padctl *padctl,
568 				    unsigned int index)
569 {
570 	struct tegra_xusb_usb2_port *usb2;
571 	struct device_node *np;
572 	int err = 0;
573 
574 	/*
575 	 * USB2 ports don't require additional properties, but if the port is
576 	 * marked as disabled there is no reason to register it.
577 	 */
578 	np = tegra_xusb_find_port_node(padctl, "usb2", index);
579 	if (!np || !of_device_is_available(np))
580 		goto out;
581 
582 	usb2 = devm_kzalloc(padctl->dev, sizeof(*usb2), GFP_KERNEL);
583 	if (!usb2) {
584 		err = -ENOMEM;
585 		goto out;
586 	}
587 
588 	err = tegra_xusb_port_init(&usb2->base, padctl, np, "usb2", index);
589 	if (err < 0)
590 		goto out;
591 
592 	usb2->base.ops = padctl->soc->ports.usb2.ops;
593 
594 	usb2->base.lane = usb2->base.ops->map(&usb2->base);
595 	if (IS_ERR(usb2->base.lane)) {
596 		err = PTR_ERR(usb2->base.lane);
597 		goto out;
598 	}
599 
600 	err = tegra_xusb_usb2_port_parse_dt(usb2);
601 	if (err < 0) {
602 		tegra_xusb_port_unregister(&usb2->base);
603 		goto out;
604 	}
605 
606 	list_add_tail(&usb2->base.list, &padctl->ports);
607 
608 out:
609 	of_node_put(np);
610 	return err;
611 }
612 
613 static int tegra_xusb_ulpi_port_parse_dt(struct tegra_xusb_ulpi_port *ulpi)
614 {
615 	struct tegra_xusb_port *port = &ulpi->base;
616 	struct device_node *np = port->dev.of_node;
617 
618 	ulpi->internal = of_property_read_bool(np, "nvidia,internal");
619 
620 	return 0;
621 }
622 
623 static int tegra_xusb_add_ulpi_port(struct tegra_xusb_padctl *padctl,
624 				    unsigned int index)
625 {
626 	struct tegra_xusb_ulpi_port *ulpi;
627 	struct device_node *np;
628 	int err = 0;
629 
630 	np = tegra_xusb_find_port_node(padctl, "ulpi", index);
631 	if (!np || !of_device_is_available(np))
632 		goto out;
633 
634 	ulpi = devm_kzalloc(padctl->dev, sizeof(*ulpi), GFP_KERNEL);
635 	if (!ulpi) {
636 		err = -ENOMEM;
637 		goto out;
638 	}
639 
640 	err = tegra_xusb_port_init(&ulpi->base, padctl, np, "ulpi", index);
641 	if (err < 0)
642 		goto out;
643 
644 	ulpi->base.ops = padctl->soc->ports.ulpi.ops;
645 
646 	ulpi->base.lane = ulpi->base.ops->map(&ulpi->base);
647 	if (IS_ERR(ulpi->base.lane)) {
648 		err = PTR_ERR(ulpi->base.lane);
649 		goto out;
650 	}
651 
652 	err = tegra_xusb_ulpi_port_parse_dt(ulpi);
653 	if (err < 0) {
654 		tegra_xusb_port_unregister(&ulpi->base);
655 		goto out;
656 	}
657 
658 	list_add_tail(&ulpi->base.list, &padctl->ports);
659 
660 out:
661 	of_node_put(np);
662 	return err;
663 }
664 
665 static int tegra_xusb_hsic_port_parse_dt(struct tegra_xusb_hsic_port *hsic)
666 {
667 	/* XXX */
668 	return 0;
669 }
670 
671 static int tegra_xusb_add_hsic_port(struct tegra_xusb_padctl *padctl,
672 				    unsigned int index)
673 {
674 	struct tegra_xusb_hsic_port *hsic;
675 	struct device_node *np;
676 	int err = 0;
677 
678 	np = tegra_xusb_find_port_node(padctl, "hsic", index);
679 	if (!np || !of_device_is_available(np))
680 		goto out;
681 
682 	hsic = devm_kzalloc(padctl->dev, sizeof(*hsic), GFP_KERNEL);
683 	if (!hsic) {
684 		err = -ENOMEM;
685 		goto out;
686 	}
687 
688 	err = tegra_xusb_port_init(&hsic->base, padctl, np, "hsic", index);
689 	if (err < 0)
690 		goto out;
691 
692 	hsic->base.ops = padctl->soc->ports.hsic.ops;
693 
694 	hsic->base.lane = hsic->base.ops->map(&hsic->base);
695 	if (IS_ERR(hsic->base.lane)) {
696 		err = PTR_ERR(hsic->base.lane);
697 		goto out;
698 	}
699 
700 	err = tegra_xusb_hsic_port_parse_dt(hsic);
701 	if (err < 0) {
702 		tegra_xusb_port_unregister(&hsic->base);
703 		goto out;
704 	}
705 
706 	list_add_tail(&hsic->base.list, &padctl->ports);
707 
708 out:
709 	of_node_put(np);
710 	return err;
711 }
712 
713 static int tegra_xusb_usb3_port_parse_dt(struct tegra_xusb_usb3_port *usb3)
714 {
715 	struct tegra_xusb_port *port = &usb3->base;
716 	struct device_node *np = port->dev.of_node;
717 	u32 value;
718 	int err;
719 
720 	err = of_property_read_u32(np, "nvidia,usb2-companion", &value);
721 	if (err < 0) {
722 		dev_err(&port->dev, "failed to read port: %d\n", err);
723 		return err;
724 	}
725 
726 	usb3->port = value;
727 
728 	usb3->internal = of_property_read_bool(np, "nvidia,internal");
729 
730 	usb3->supply = devm_regulator_get(&port->dev, "vbus");
731 	return PTR_ERR_OR_ZERO(usb3->supply);
732 }
733 
734 static int tegra_xusb_add_usb3_port(struct tegra_xusb_padctl *padctl,
735 				    unsigned int index)
736 {
737 	struct tegra_xusb_usb3_port *usb3;
738 	struct device_node *np;
739 	int err = 0;
740 
741 	/*
742 	 * If there is no supplemental configuration in the device tree the
743 	 * port is unusable. But it is valid to configure only a single port,
744 	 * hence return 0 instead of an error to allow ports to be optional.
745 	 */
746 	np = tegra_xusb_find_port_node(padctl, "usb3", index);
747 	if (!np || !of_device_is_available(np))
748 		goto out;
749 
750 	usb3 = devm_kzalloc(padctl->dev, sizeof(*usb3), GFP_KERNEL);
751 	if (!usb3) {
752 		err = -ENOMEM;
753 		goto out;
754 	}
755 
756 	err = tegra_xusb_port_init(&usb3->base, padctl, np, "usb3", index);
757 	if (err < 0)
758 		goto out;
759 
760 	usb3->base.ops = padctl->soc->ports.usb3.ops;
761 
762 	usb3->base.lane = usb3->base.ops->map(&usb3->base);
763 	if (IS_ERR(usb3->base.lane)) {
764 		err = PTR_ERR(usb3->base.lane);
765 		goto out;
766 	}
767 
768 	err = tegra_xusb_usb3_port_parse_dt(usb3);
769 	if (err < 0) {
770 		tegra_xusb_port_unregister(&usb3->base);
771 		goto out;
772 	}
773 
774 	list_add_tail(&usb3->base.list, &padctl->ports);
775 
776 out:
777 	of_node_put(np);
778 	return err;
779 }
780 
781 static void __tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
782 {
783 	struct tegra_xusb_port *port, *tmp;
784 
785 	list_for_each_entry_safe_reverse(port, tmp, &padctl->ports, list) {
786 		list_del(&port->list);
787 		tegra_xusb_port_unregister(port);
788 	}
789 }
790 
791 static int tegra_xusb_setup_ports(struct tegra_xusb_padctl *padctl)
792 {
793 	struct tegra_xusb_port *port;
794 	unsigned int i;
795 	int err = 0;
796 
797 	mutex_lock(&padctl->lock);
798 
799 	for (i = 0; i < padctl->soc->ports.usb2.count; i++) {
800 		err = tegra_xusb_add_usb2_port(padctl, i);
801 		if (err < 0)
802 			goto remove_ports;
803 	}
804 
805 	for (i = 0; i < padctl->soc->ports.ulpi.count; i++) {
806 		err = tegra_xusb_add_ulpi_port(padctl, i);
807 		if (err < 0)
808 			goto remove_ports;
809 	}
810 
811 	for (i = 0; i < padctl->soc->ports.hsic.count; i++) {
812 		err = tegra_xusb_add_hsic_port(padctl, i);
813 		if (err < 0)
814 			goto remove_ports;
815 	}
816 
817 	for (i = 0; i < padctl->soc->ports.usb3.count; i++) {
818 		err = tegra_xusb_add_usb3_port(padctl, i);
819 		if (err < 0)
820 			goto remove_ports;
821 	}
822 
823 	list_for_each_entry(port, &padctl->ports, list) {
824 		err = port->ops->enable(port);
825 		if (err < 0)
826 			dev_err(padctl->dev, "failed to enable port %s: %d\n",
827 				dev_name(&port->dev), err);
828 	}
829 
830 	goto unlock;
831 
832 remove_ports:
833 	__tegra_xusb_remove_ports(padctl);
834 unlock:
835 	mutex_unlock(&padctl->lock);
836 	return err;
837 }
838 
839 static void tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
840 {
841 	mutex_lock(&padctl->lock);
842 	__tegra_xusb_remove_ports(padctl);
843 	mutex_unlock(&padctl->lock);
844 }
845 
846 static int tegra_xusb_padctl_probe(struct platform_device *pdev)
847 {
848 	struct device_node *np = of_node_get(pdev->dev.of_node);
849 	const struct tegra_xusb_padctl_soc *soc;
850 	struct tegra_xusb_padctl *padctl;
851 	const struct of_device_id *match;
852 	struct resource *res;
853 	int err;
854 
855 	/* for backwards compatibility with old device trees */
856 	np = of_find_node_by_name(np, "pads");
857 	if (!np) {
858 		dev_warn(&pdev->dev, "deprecated DT, using legacy driver\n");
859 		return tegra_xusb_padctl_legacy_probe(pdev);
860 	}
861 
862 	of_node_put(np);
863 
864 	match = of_match_node(tegra_xusb_padctl_of_match, pdev->dev.of_node);
865 	soc = match->data;
866 
867 	padctl = soc->ops->probe(&pdev->dev, soc);
868 	if (IS_ERR(padctl))
869 		return PTR_ERR(padctl);
870 
871 	platform_set_drvdata(pdev, padctl);
872 	INIT_LIST_HEAD(&padctl->ports);
873 	INIT_LIST_HEAD(&padctl->lanes);
874 	INIT_LIST_HEAD(&padctl->pads);
875 	mutex_init(&padctl->lock);
876 
877 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
878 	padctl->regs = devm_ioremap_resource(&pdev->dev, res);
879 	if (IS_ERR(padctl->regs)) {
880 		err = PTR_ERR(padctl->regs);
881 		goto remove;
882 	}
883 
884 	padctl->rst = devm_reset_control_get(&pdev->dev, NULL);
885 	if (IS_ERR(padctl->rst)) {
886 		err = PTR_ERR(padctl->rst);
887 		goto remove;
888 	}
889 
890 	err = reset_control_deassert(padctl->rst);
891 	if (err < 0)
892 		goto remove;
893 
894 	err = tegra_xusb_setup_pads(padctl);
895 	if (err < 0) {
896 		dev_err(&pdev->dev, "failed to setup pads: %d\n", err);
897 		goto reset;
898 	}
899 
900 	err = tegra_xusb_setup_ports(padctl);
901 	if (err) {
902 		dev_err(&pdev->dev, "failed to setup XUSB ports: %d\n", err);
903 		goto remove_pads;
904 	}
905 
906 	return 0;
907 
908 remove_pads:
909 	tegra_xusb_remove_pads(padctl);
910 reset:
911 	reset_control_assert(padctl->rst);
912 remove:
913 	soc->ops->remove(padctl);
914 	return err;
915 }
916 
917 static int tegra_xusb_padctl_remove(struct platform_device *pdev)
918 {
919 	struct tegra_xusb_padctl *padctl = platform_get_drvdata(pdev);
920 	int err;
921 
922 	tegra_xusb_remove_ports(padctl);
923 	tegra_xusb_remove_pads(padctl);
924 
925 	err = reset_control_assert(padctl->rst);
926 	if (err < 0)
927 		dev_err(&pdev->dev, "failed to assert reset: %d\n", err);
928 
929 	padctl->soc->ops->remove(padctl);
930 
931 	return err;
932 }
933 
934 static struct platform_driver tegra_xusb_padctl_driver = {
935 	.driver = {
936 		.name = "tegra-xusb-padctl",
937 		.of_match_table = tegra_xusb_padctl_of_match,
938 	},
939 	.probe = tegra_xusb_padctl_probe,
940 	.remove = tegra_xusb_padctl_remove,
941 };
942 module_platform_driver(tegra_xusb_padctl_driver);
943 
944 struct tegra_xusb_padctl *tegra_xusb_padctl_get(struct device *dev)
945 {
946 	struct tegra_xusb_padctl *padctl;
947 	struct platform_device *pdev;
948 	struct device_node *np;
949 
950 	np = of_parse_phandle(dev->of_node, "nvidia,xusb-padctl", 0);
951 	if (!np)
952 		return ERR_PTR(-EINVAL);
953 
954 	/*
955 	 * This is slightly ugly. A better implementation would be to keep a
956 	 * registry of pad controllers, but since there will almost certainly
957 	 * only ever be one per SoC that would be a little overkill.
958 	 */
959 	pdev = of_find_device_by_node(np);
960 	if (!pdev) {
961 		of_node_put(np);
962 		return ERR_PTR(-ENODEV);
963 	}
964 
965 	of_node_put(np);
966 
967 	padctl = platform_get_drvdata(pdev);
968 	if (!padctl) {
969 		put_device(&pdev->dev);
970 		return ERR_PTR(-EPROBE_DEFER);
971 	}
972 
973 	return padctl;
974 }
975 EXPORT_SYMBOL_GPL(tegra_xusb_padctl_get);
976 
977 void tegra_xusb_padctl_put(struct tegra_xusb_padctl *padctl)
978 {
979 	if (padctl)
980 		put_device(padctl->dev);
981 }
982 EXPORT_SYMBOL_GPL(tegra_xusb_padctl_put);
983 
984 int tegra_xusb_padctl_usb3_save_context(struct tegra_xusb_padctl *padctl,
985 					unsigned int port)
986 {
987 	if (padctl->soc->ops->usb3_save_context)
988 		return padctl->soc->ops->usb3_save_context(padctl, port);
989 
990 	return -ENOSYS;
991 }
992 EXPORT_SYMBOL_GPL(tegra_xusb_padctl_usb3_save_context);
993 
994 int tegra_xusb_padctl_hsic_set_idle(struct tegra_xusb_padctl *padctl,
995 				    unsigned int port, bool idle)
996 {
997 	if (padctl->soc->ops->hsic_set_idle)
998 		return padctl->soc->ops->hsic_set_idle(padctl, port, idle);
999 
1000 	return -ENOSYS;
1001 }
1002 EXPORT_SYMBOL_GPL(tegra_xusb_padctl_hsic_set_idle);
1003 
1004 int tegra_xusb_padctl_usb3_set_lfps_detect(struct tegra_xusb_padctl *padctl,
1005 					   unsigned int port, bool enable)
1006 {
1007 	if (padctl->soc->ops->usb3_set_lfps_detect)
1008 		return padctl->soc->ops->usb3_set_lfps_detect(padctl, port,
1009 							      enable);
1010 
1011 	return -ENOSYS;
1012 }
1013 EXPORT_SYMBOL_GPL(tegra_xusb_padctl_usb3_set_lfps_detect);
1014 
1015 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
1016 MODULE_DESCRIPTION("Tegra XUSB Pad Controller driver");
1017 MODULE_LICENSE("GPL v2");
1018