xref: /openbmc/linux/net/dsa/dsa.c (revision 32981ea5)
1 /*
2  * net/dsa/dsa.c - Hardware switch handling
3  * Copyright (c) 2008-2009 Marvell Semiconductor
4  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/ctype.h>
13 #include <linux/device.h>
14 #include <linux/hwmon.h>
15 #include <linux/list.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <net/dsa.h>
20 #include <linux/of.h>
21 #include <linux/of_mdio.h>
22 #include <linux/of_platform.h>
23 #include <linux/of_net.h>
24 #include <linux/of_gpio.h>
25 #include <linux/sysfs.h>
26 #include <linux/phy_fixed.h>
27 #include <linux/gpio/consumer.h>
28 #include "dsa_priv.h"
29 
30 char dsa_driver_version[] = "0.1";
31 
32 
33 /* switch driver registration ***********************************************/
34 static DEFINE_MUTEX(dsa_switch_drivers_mutex);
35 static LIST_HEAD(dsa_switch_drivers);
36 
37 void register_switch_driver(struct dsa_switch_driver *drv)
38 {
39 	mutex_lock(&dsa_switch_drivers_mutex);
40 	list_add_tail(&drv->list, &dsa_switch_drivers);
41 	mutex_unlock(&dsa_switch_drivers_mutex);
42 }
43 EXPORT_SYMBOL_GPL(register_switch_driver);
44 
45 void unregister_switch_driver(struct dsa_switch_driver *drv)
46 {
47 	mutex_lock(&dsa_switch_drivers_mutex);
48 	list_del_init(&drv->list);
49 	mutex_unlock(&dsa_switch_drivers_mutex);
50 }
51 EXPORT_SYMBOL_GPL(unregister_switch_driver);
52 
53 static struct dsa_switch_driver *
54 dsa_switch_probe(struct device *parent, struct device *host_dev, int sw_addr,
55 		 const char **_name, void **priv)
56 {
57 	struct dsa_switch_driver *ret;
58 	struct list_head *list;
59 	const char *name;
60 
61 	ret = NULL;
62 	name = NULL;
63 
64 	mutex_lock(&dsa_switch_drivers_mutex);
65 	list_for_each(list, &dsa_switch_drivers) {
66 		struct dsa_switch_driver *drv;
67 
68 		drv = list_entry(list, struct dsa_switch_driver, list);
69 
70 		name = drv->probe(parent, host_dev, sw_addr, priv);
71 		if (name != NULL) {
72 			ret = drv;
73 			break;
74 		}
75 	}
76 	mutex_unlock(&dsa_switch_drivers_mutex);
77 
78 	*_name = name;
79 
80 	return ret;
81 }
82 
83 /* hwmon support ************************************************************/
84 
85 #ifdef CONFIG_NET_DSA_HWMON
86 
87 static ssize_t temp1_input_show(struct device *dev,
88 				struct device_attribute *attr, char *buf)
89 {
90 	struct dsa_switch *ds = dev_get_drvdata(dev);
91 	int temp, ret;
92 
93 	ret = ds->drv->get_temp(ds, &temp);
94 	if (ret < 0)
95 		return ret;
96 
97 	return sprintf(buf, "%d\n", temp * 1000);
98 }
99 static DEVICE_ATTR_RO(temp1_input);
100 
101 static ssize_t temp1_max_show(struct device *dev,
102 			      struct device_attribute *attr, char *buf)
103 {
104 	struct dsa_switch *ds = dev_get_drvdata(dev);
105 	int temp, ret;
106 
107 	ret = ds->drv->get_temp_limit(ds, &temp);
108 	if (ret < 0)
109 		return ret;
110 
111 	return sprintf(buf, "%d\n", temp * 1000);
112 }
113 
114 static ssize_t temp1_max_store(struct device *dev,
115 			       struct device_attribute *attr, const char *buf,
116 			       size_t count)
117 {
118 	struct dsa_switch *ds = dev_get_drvdata(dev);
119 	int temp, ret;
120 
121 	ret = kstrtoint(buf, 0, &temp);
122 	if (ret < 0)
123 		return ret;
124 
125 	ret = ds->drv->set_temp_limit(ds, DIV_ROUND_CLOSEST(temp, 1000));
126 	if (ret < 0)
127 		return ret;
128 
129 	return count;
130 }
131 static DEVICE_ATTR_RW(temp1_max);
132 
133 static ssize_t temp1_max_alarm_show(struct device *dev,
134 				    struct device_attribute *attr, char *buf)
135 {
136 	struct dsa_switch *ds = dev_get_drvdata(dev);
137 	bool alarm;
138 	int ret;
139 
140 	ret = ds->drv->get_temp_alarm(ds, &alarm);
141 	if (ret < 0)
142 		return ret;
143 
144 	return sprintf(buf, "%d\n", alarm);
145 }
146 static DEVICE_ATTR_RO(temp1_max_alarm);
147 
148 static struct attribute *dsa_hwmon_attrs[] = {
149 	&dev_attr_temp1_input.attr,	/* 0 */
150 	&dev_attr_temp1_max.attr,	/* 1 */
151 	&dev_attr_temp1_max_alarm.attr,	/* 2 */
152 	NULL
153 };
154 
155 static umode_t dsa_hwmon_attrs_visible(struct kobject *kobj,
156 				       struct attribute *attr, int index)
157 {
158 	struct device *dev = container_of(kobj, struct device, kobj);
159 	struct dsa_switch *ds = dev_get_drvdata(dev);
160 	struct dsa_switch_driver *drv = ds->drv;
161 	umode_t mode = attr->mode;
162 
163 	if (index == 1) {
164 		if (!drv->get_temp_limit)
165 			mode = 0;
166 		else if (!drv->set_temp_limit)
167 			mode &= ~S_IWUSR;
168 	} else if (index == 2 && !drv->get_temp_alarm) {
169 		mode = 0;
170 	}
171 	return mode;
172 }
173 
174 static const struct attribute_group dsa_hwmon_group = {
175 	.attrs = dsa_hwmon_attrs,
176 	.is_visible = dsa_hwmon_attrs_visible,
177 };
178 __ATTRIBUTE_GROUPS(dsa_hwmon);
179 
180 #endif /* CONFIG_NET_DSA_HWMON */
181 
182 /* basic switch operations **************************************************/
183 static int dsa_cpu_dsa_setup(struct dsa_switch *ds, struct net_device *master)
184 {
185 	struct dsa_chip_data *cd = ds->cd;
186 	struct device_node *port_dn;
187 	struct phy_device *phydev;
188 	int ret, port, mode;
189 
190 	for (port = 0; port < DSA_MAX_PORTS; port++) {
191 		if (!(dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
192 			continue;
193 
194 		port_dn = cd->port_dn[port];
195 		if (of_phy_is_fixed_link(port_dn)) {
196 			ret = of_phy_register_fixed_link(port_dn);
197 			if (ret) {
198 				netdev_err(master,
199 					   "failed to register fixed PHY\n");
200 				return ret;
201 			}
202 			phydev = of_phy_find_device(port_dn);
203 
204 			mode = of_get_phy_mode(port_dn);
205 			if (mode < 0)
206 				mode = PHY_INTERFACE_MODE_NA;
207 			phydev->interface = mode;
208 
209 			genphy_config_init(phydev);
210 			genphy_read_status(phydev);
211 			if (ds->drv->adjust_link)
212 				ds->drv->adjust_link(ds, port, phydev);
213 		}
214 	}
215 	return 0;
216 }
217 
218 static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
219 {
220 	struct dsa_switch_driver *drv = ds->drv;
221 	struct dsa_switch_tree *dst = ds->dst;
222 	struct dsa_chip_data *cd = ds->cd;
223 	bool valid_name_found = false;
224 	int index = ds->index;
225 	int i, ret;
226 
227 	/*
228 	 * Validate supplied switch configuration.
229 	 */
230 	for (i = 0; i < DSA_MAX_PORTS; i++) {
231 		char *name;
232 
233 		name = cd->port_names[i];
234 		if (name == NULL)
235 			continue;
236 
237 		if (!strcmp(name, "cpu")) {
238 			if (dst->cpu_switch != -1) {
239 				netdev_err(dst->master_netdev,
240 					   "multiple cpu ports?!\n");
241 				ret = -EINVAL;
242 				goto out;
243 			}
244 			dst->cpu_switch = index;
245 			dst->cpu_port = i;
246 		} else if (!strcmp(name, "dsa")) {
247 			ds->dsa_port_mask |= 1 << i;
248 		} else {
249 			ds->enabled_port_mask |= 1 << i;
250 		}
251 		valid_name_found = true;
252 	}
253 
254 	if (!valid_name_found && i == DSA_MAX_PORTS) {
255 		ret = -EINVAL;
256 		goto out;
257 	}
258 
259 	/* Make the built-in MII bus mask match the number of ports,
260 	 * switch drivers can override this later
261 	 */
262 	ds->phys_mii_mask = ds->enabled_port_mask;
263 
264 	/*
265 	 * If the CPU connects to this switch, set the switch tree
266 	 * tagging protocol to the preferred tagging format of this
267 	 * switch.
268 	 */
269 	if (dst->cpu_switch == index) {
270 		switch (drv->tag_protocol) {
271 #ifdef CONFIG_NET_DSA_TAG_DSA
272 		case DSA_TAG_PROTO_DSA:
273 			dst->rcv = dsa_netdev_ops.rcv;
274 			break;
275 #endif
276 #ifdef CONFIG_NET_DSA_TAG_EDSA
277 		case DSA_TAG_PROTO_EDSA:
278 			dst->rcv = edsa_netdev_ops.rcv;
279 			break;
280 #endif
281 #ifdef CONFIG_NET_DSA_TAG_TRAILER
282 		case DSA_TAG_PROTO_TRAILER:
283 			dst->rcv = trailer_netdev_ops.rcv;
284 			break;
285 #endif
286 #ifdef CONFIG_NET_DSA_TAG_BRCM
287 		case DSA_TAG_PROTO_BRCM:
288 			dst->rcv = brcm_netdev_ops.rcv;
289 			break;
290 #endif
291 		case DSA_TAG_PROTO_NONE:
292 			break;
293 		default:
294 			ret = -ENOPROTOOPT;
295 			goto out;
296 		}
297 
298 		dst->tag_protocol = drv->tag_protocol;
299 	}
300 
301 	/*
302 	 * Do basic register setup.
303 	 */
304 	ret = drv->setup(ds);
305 	if (ret < 0)
306 		goto out;
307 
308 	ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
309 	if (ret < 0)
310 		goto out;
311 
312 	ds->slave_mii_bus = devm_mdiobus_alloc(parent);
313 	if (ds->slave_mii_bus == NULL) {
314 		ret = -ENOMEM;
315 		goto out;
316 	}
317 	dsa_slave_mii_bus_init(ds);
318 
319 	ret = mdiobus_register(ds->slave_mii_bus);
320 	if (ret < 0)
321 		goto out;
322 
323 
324 	/*
325 	 * Create network devices for physical switch ports.
326 	 */
327 	for (i = 0; i < DSA_MAX_PORTS; i++) {
328 		if (!(ds->enabled_port_mask & (1 << i)))
329 			continue;
330 
331 		ret = dsa_slave_create(ds, parent, i, cd->port_names[i]);
332 		if (ret < 0) {
333 			netdev_err(dst->master_netdev, "[%d]: can't create dsa slave device for port %d(%s): %d\n",
334 				   index, i, cd->port_names[i], ret);
335 			ret = 0;
336 		}
337 	}
338 
339 	/* Perform configuration of the CPU and DSA ports */
340 	ret = dsa_cpu_dsa_setup(ds, dst->master_netdev);
341 	if (ret < 0) {
342 		netdev_err(dst->master_netdev, "[%d] : can't configure CPU and DSA ports\n",
343 			   index);
344 		ret = 0;
345 	}
346 
347 #ifdef CONFIG_NET_DSA_HWMON
348 	/* If the switch provides a temperature sensor,
349 	 * register with hardware monitoring subsystem.
350 	 * Treat registration error as non-fatal and ignore it.
351 	 */
352 	if (drv->get_temp) {
353 		const char *netname = netdev_name(dst->master_netdev);
354 		char hname[IFNAMSIZ + 1];
355 		int i, j;
356 
357 		/* Create valid hwmon 'name' attribute */
358 		for (i = j = 0; i < IFNAMSIZ && netname[i]; i++) {
359 			if (isalnum(netname[i]))
360 				hname[j++] = netname[i];
361 		}
362 		hname[j] = '\0';
363 		scnprintf(ds->hwmon_name, sizeof(ds->hwmon_name), "%s_dsa%d",
364 			  hname, index);
365 		ds->hwmon_dev = hwmon_device_register_with_groups(NULL,
366 					ds->hwmon_name, ds, dsa_hwmon_groups);
367 		if (IS_ERR(ds->hwmon_dev))
368 			ds->hwmon_dev = NULL;
369 	}
370 #endif /* CONFIG_NET_DSA_HWMON */
371 
372 	return ret;
373 
374 out:
375 	return ret;
376 }
377 
378 static struct dsa_switch *
379 dsa_switch_setup(struct dsa_switch_tree *dst, int index,
380 		 struct device *parent, struct device *host_dev)
381 {
382 	struct dsa_chip_data *cd = dst->pd->chip + index;
383 	struct dsa_switch_driver *drv;
384 	struct dsa_switch *ds;
385 	int ret;
386 	const char *name;
387 	void *priv;
388 
389 	/*
390 	 * Probe for switch model.
391 	 */
392 	drv = dsa_switch_probe(parent, host_dev, cd->sw_addr, &name, &priv);
393 	if (drv == NULL) {
394 		netdev_err(dst->master_netdev, "[%d]: could not detect attached switch\n",
395 			   index);
396 		return ERR_PTR(-EINVAL);
397 	}
398 	netdev_info(dst->master_netdev, "[%d]: detected a %s switch\n",
399 		    index, name);
400 
401 
402 	/*
403 	 * Allocate and initialise switch state.
404 	 */
405 	ds = devm_kzalloc(parent, sizeof(*ds), GFP_KERNEL);
406 	if (ds == NULL)
407 		return ERR_PTR(-ENOMEM);
408 
409 	ds->dst = dst;
410 	ds->index = index;
411 	ds->cd = cd;
412 	ds->drv = drv;
413 	ds->priv = priv;
414 	ds->dev = parent;
415 
416 	ret = dsa_switch_setup_one(ds, parent);
417 	if (ret)
418 		return ERR_PTR(ret);
419 
420 	return ds;
421 }
422 
423 static void dsa_switch_destroy(struct dsa_switch *ds)
424 {
425 	struct device_node *port_dn;
426 	struct phy_device *phydev;
427 	struct dsa_chip_data *cd = ds->cd;
428 	int port;
429 
430 #ifdef CONFIG_NET_DSA_HWMON
431 	if (ds->hwmon_dev)
432 		hwmon_device_unregister(ds->hwmon_dev);
433 #endif
434 
435 	/* Destroy network devices for physical switch ports. */
436 	for (port = 0; port < DSA_MAX_PORTS; port++) {
437 		if (!(ds->enabled_port_mask & (1 << port)))
438 			continue;
439 
440 		if (!ds->ports[port])
441 			continue;
442 
443 		dsa_slave_destroy(ds->ports[port]);
444 	}
445 
446 	/* Remove any fixed link PHYs */
447 	for (port = 0; port < DSA_MAX_PORTS; port++) {
448 		port_dn = cd->port_dn[port];
449 		if (of_phy_is_fixed_link(port_dn)) {
450 			phydev = of_phy_find_device(port_dn);
451 			if (phydev) {
452 				phy_device_free(phydev);
453 				of_node_put(port_dn);
454 				fixed_phy_unregister(phydev);
455 			}
456 		}
457 	}
458 
459 	mdiobus_unregister(ds->slave_mii_bus);
460 }
461 
462 #ifdef CONFIG_PM_SLEEP
463 static int dsa_switch_suspend(struct dsa_switch *ds)
464 {
465 	int i, ret = 0;
466 
467 	/* Suspend slave network devices */
468 	for (i = 0; i < DSA_MAX_PORTS; i++) {
469 		if (!dsa_is_port_initialized(ds, i))
470 			continue;
471 
472 		ret = dsa_slave_suspend(ds->ports[i]);
473 		if (ret)
474 			return ret;
475 	}
476 
477 	if (ds->drv->suspend)
478 		ret = ds->drv->suspend(ds);
479 
480 	return ret;
481 }
482 
483 static int dsa_switch_resume(struct dsa_switch *ds)
484 {
485 	int i, ret = 0;
486 
487 	if (ds->drv->resume)
488 		ret = ds->drv->resume(ds);
489 
490 	if (ret)
491 		return ret;
492 
493 	/* Resume slave network devices */
494 	for (i = 0; i < DSA_MAX_PORTS; i++) {
495 		if (!dsa_is_port_initialized(ds, i))
496 			continue;
497 
498 		ret = dsa_slave_resume(ds->ports[i]);
499 		if (ret)
500 			return ret;
501 	}
502 
503 	return 0;
504 }
505 #endif
506 
507 /* platform driver init and cleanup *****************************************/
508 static int dev_is_class(struct device *dev, void *class)
509 {
510 	if (dev->class != NULL && !strcmp(dev->class->name, class))
511 		return 1;
512 
513 	return 0;
514 }
515 
516 static struct device *dev_find_class(struct device *parent, char *class)
517 {
518 	if (dev_is_class(parent, class)) {
519 		get_device(parent);
520 		return parent;
521 	}
522 
523 	return device_find_child(parent, class, dev_is_class);
524 }
525 
526 struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev)
527 {
528 	struct device *d;
529 
530 	d = dev_find_class(dev, "mdio_bus");
531 	if (d != NULL) {
532 		struct mii_bus *bus;
533 
534 		bus = to_mii_bus(d);
535 		put_device(d);
536 
537 		return bus;
538 	}
539 
540 	return NULL;
541 }
542 EXPORT_SYMBOL_GPL(dsa_host_dev_to_mii_bus);
543 
544 static struct net_device *dev_to_net_device(struct device *dev)
545 {
546 	struct device *d;
547 
548 	d = dev_find_class(dev, "net");
549 	if (d != NULL) {
550 		struct net_device *nd;
551 
552 		nd = to_net_dev(d);
553 		dev_hold(nd);
554 		put_device(d);
555 
556 		return nd;
557 	}
558 
559 	return NULL;
560 }
561 
562 #ifdef CONFIG_OF
563 static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
564 					struct dsa_chip_data *cd,
565 					int chip_index, int port_index,
566 					struct device_node *link)
567 {
568 	const __be32 *reg;
569 	int link_sw_addr;
570 	struct device_node *parent_sw;
571 	int len;
572 
573 	parent_sw = of_get_parent(link);
574 	if (!parent_sw)
575 		return -EINVAL;
576 
577 	reg = of_get_property(parent_sw, "reg", &len);
578 	if (!reg || (len != sizeof(*reg) * 2))
579 		return -EINVAL;
580 
581 	/*
582 	 * Get the destination switch number from the second field of its 'reg'
583 	 * property, i.e. for "reg = <0x19 1>" sw_addr is '1'.
584 	 */
585 	link_sw_addr = be32_to_cpup(reg + 1);
586 
587 	if (link_sw_addr >= pd->nr_chips)
588 		return -EINVAL;
589 
590 	/* First time routing table allocation */
591 	if (!cd->rtable) {
592 		cd->rtable = kmalloc_array(pd->nr_chips, sizeof(s8),
593 					   GFP_KERNEL);
594 		if (!cd->rtable)
595 			return -ENOMEM;
596 
597 		/* default to no valid uplink/downlink */
598 		memset(cd->rtable, -1, pd->nr_chips * sizeof(s8));
599 	}
600 
601 	cd->rtable[link_sw_addr] = port_index;
602 
603 	return 0;
604 }
605 
606 static int dsa_of_probe_links(struct dsa_platform_data *pd,
607 			      struct dsa_chip_data *cd,
608 			      int chip_index, int port_index,
609 			      struct device_node *port,
610 			      const char *port_name)
611 {
612 	struct device_node *link;
613 	int link_index;
614 	int ret;
615 
616 	for (link_index = 0;; link_index++) {
617 		link = of_parse_phandle(port, "link", link_index);
618 		if (!link)
619 			break;
620 
621 		if (!strcmp(port_name, "dsa") && pd->nr_chips > 1) {
622 			ret = dsa_of_setup_routing_table(pd, cd, chip_index,
623 							 port_index, link);
624 			if (ret)
625 				return ret;
626 		}
627 	}
628 	return 0;
629 }
630 
631 static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
632 {
633 	int i;
634 	int port_index;
635 
636 	for (i = 0; i < pd->nr_chips; i++) {
637 		port_index = 0;
638 		while (port_index < DSA_MAX_PORTS) {
639 			kfree(pd->chip[i].port_names[port_index]);
640 			port_index++;
641 		}
642 		kfree(pd->chip[i].rtable);
643 
644 		/* Drop our reference to the MDIO bus device */
645 		if (pd->chip[i].host_dev)
646 			put_device(pd->chip[i].host_dev);
647 	}
648 	kfree(pd->chip);
649 }
650 
651 static int dsa_of_probe(struct device *dev)
652 {
653 	struct device_node *np = dev->of_node;
654 	struct device_node *child, *mdio, *ethernet, *port;
655 	struct mii_bus *mdio_bus, *mdio_bus_switch;
656 	struct net_device *ethernet_dev;
657 	struct dsa_platform_data *pd;
658 	struct dsa_chip_data *cd;
659 	const char *port_name;
660 	int chip_index, port_index;
661 	const unsigned int *sw_addr, *port_reg;
662 	u32 eeprom_len;
663 	int ret;
664 
665 	mdio = of_parse_phandle(np, "dsa,mii-bus", 0);
666 	if (!mdio)
667 		return -EINVAL;
668 
669 	mdio_bus = of_mdio_find_bus(mdio);
670 	if (!mdio_bus)
671 		return -EPROBE_DEFER;
672 
673 	ethernet = of_parse_phandle(np, "dsa,ethernet", 0);
674 	if (!ethernet) {
675 		ret = -EINVAL;
676 		goto out_put_mdio;
677 	}
678 
679 	ethernet_dev = of_find_net_device_by_node(ethernet);
680 	if (!ethernet_dev) {
681 		ret = -EPROBE_DEFER;
682 		goto out_put_mdio;
683 	}
684 
685 	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
686 	if (!pd) {
687 		ret = -ENOMEM;
688 		goto out_put_ethernet;
689 	}
690 
691 	dev->platform_data = pd;
692 	pd->of_netdev = ethernet_dev;
693 	pd->nr_chips = of_get_available_child_count(np);
694 	if (pd->nr_chips > DSA_MAX_SWITCHES)
695 		pd->nr_chips = DSA_MAX_SWITCHES;
696 
697 	pd->chip = kcalloc(pd->nr_chips, sizeof(struct dsa_chip_data),
698 			   GFP_KERNEL);
699 	if (!pd->chip) {
700 		ret = -ENOMEM;
701 		goto out_free;
702 	}
703 
704 	chip_index = -1;
705 	for_each_available_child_of_node(np, child) {
706 		chip_index++;
707 		cd = &pd->chip[chip_index];
708 
709 		cd->of_node = child;
710 
711 		/* When assigning the host device, increment its refcount */
712 		cd->host_dev = get_device(&mdio_bus->dev);
713 
714 		sw_addr = of_get_property(child, "reg", NULL);
715 		if (!sw_addr)
716 			continue;
717 
718 		cd->sw_addr = be32_to_cpup(sw_addr);
719 		if (cd->sw_addr >= PHY_MAX_ADDR)
720 			continue;
721 
722 		if (!of_property_read_u32(child, "eeprom-length", &eeprom_len))
723 			cd->eeprom_len = eeprom_len;
724 
725 		mdio = of_parse_phandle(child, "mii-bus", 0);
726 		if (mdio) {
727 			mdio_bus_switch = of_mdio_find_bus(mdio);
728 			if (!mdio_bus_switch) {
729 				ret = -EPROBE_DEFER;
730 				goto out_free_chip;
731 			}
732 
733 			/* Drop the mdio_bus device ref, replacing the host
734 			 * device with the mdio_bus_switch device, keeping
735 			 * the refcount from of_mdio_find_bus() above.
736 			 */
737 			put_device(cd->host_dev);
738 			cd->host_dev = &mdio_bus_switch->dev;
739 		}
740 
741 		for_each_available_child_of_node(child, port) {
742 			port_reg = of_get_property(port, "reg", NULL);
743 			if (!port_reg)
744 				continue;
745 
746 			port_index = be32_to_cpup(port_reg);
747 			if (port_index >= DSA_MAX_PORTS)
748 				break;
749 
750 			port_name = of_get_property(port, "label", NULL);
751 			if (!port_name)
752 				continue;
753 
754 			cd->port_dn[port_index] = port;
755 
756 			cd->port_names[port_index] = kstrdup(port_name,
757 					GFP_KERNEL);
758 			if (!cd->port_names[port_index]) {
759 				ret = -ENOMEM;
760 				goto out_free_chip;
761 			}
762 
763 			ret = dsa_of_probe_links(pd, cd, chip_index,
764 						 port_index, port, port_name);
765 			if (ret)
766 				goto out_free_chip;
767 
768 		}
769 	}
770 
771 	/* The individual chips hold their own refcount on the mdio bus,
772 	 * so drop ours */
773 	put_device(&mdio_bus->dev);
774 
775 	return 0;
776 
777 out_free_chip:
778 	dsa_of_free_platform_data(pd);
779 out_free:
780 	kfree(pd);
781 	dev->platform_data = NULL;
782 out_put_ethernet:
783 	put_device(&ethernet_dev->dev);
784 out_put_mdio:
785 	put_device(&mdio_bus->dev);
786 	return ret;
787 }
788 
789 static void dsa_of_remove(struct device *dev)
790 {
791 	struct dsa_platform_data *pd = dev->platform_data;
792 
793 	if (!dev->of_node)
794 		return;
795 
796 	dsa_of_free_platform_data(pd);
797 	put_device(&pd->of_netdev->dev);
798 	kfree(pd);
799 }
800 #else
801 static inline int dsa_of_probe(struct device *dev)
802 {
803 	return 0;
804 }
805 
806 static inline void dsa_of_remove(struct device *dev)
807 {
808 }
809 #endif
810 
811 static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
812 			 struct device *parent, struct dsa_platform_data *pd)
813 {
814 	int i;
815 	unsigned configured = 0;
816 
817 	dst->pd = pd;
818 	dst->master_netdev = dev;
819 	dst->cpu_switch = -1;
820 	dst->cpu_port = -1;
821 
822 	for (i = 0; i < pd->nr_chips; i++) {
823 		struct dsa_switch *ds;
824 
825 		ds = dsa_switch_setup(dst, i, parent, pd->chip[i].host_dev);
826 		if (IS_ERR(ds)) {
827 			netdev_err(dev, "[%d]: couldn't create dsa switch instance (error %ld)\n",
828 				   i, PTR_ERR(ds));
829 			continue;
830 		}
831 
832 		dst->ds[i] = ds;
833 
834 		++configured;
835 	}
836 
837 	/*
838 	 * If no switch was found, exit cleanly
839 	 */
840 	if (!configured)
841 		return -EPROBE_DEFER;
842 
843 	/*
844 	 * If we use a tagging format that doesn't have an ethertype
845 	 * field, make sure that all packets from this point on get
846 	 * sent to the tag format's receive function.
847 	 */
848 	wmb();
849 	dev->dsa_ptr = (void *)dst;
850 
851 	return 0;
852 }
853 
854 static int dsa_probe(struct platform_device *pdev)
855 {
856 	struct dsa_platform_data *pd = pdev->dev.platform_data;
857 	struct net_device *dev;
858 	struct dsa_switch_tree *dst;
859 	int ret;
860 
861 	pr_notice_once("Distributed Switch Architecture driver version %s\n",
862 		       dsa_driver_version);
863 
864 	if (pdev->dev.of_node) {
865 		ret = dsa_of_probe(&pdev->dev);
866 		if (ret)
867 			return ret;
868 
869 		pd = pdev->dev.platform_data;
870 	}
871 
872 	if (pd == NULL || (pd->netdev == NULL && pd->of_netdev == NULL))
873 		return -EINVAL;
874 
875 	if (pd->of_netdev) {
876 		dev = pd->of_netdev;
877 		dev_hold(dev);
878 	} else {
879 		dev = dev_to_net_device(pd->netdev);
880 	}
881 	if (dev == NULL) {
882 		ret = -EPROBE_DEFER;
883 		goto out;
884 	}
885 
886 	if (dev->dsa_ptr != NULL) {
887 		dev_put(dev);
888 		ret = -EEXIST;
889 		goto out;
890 	}
891 
892 	dst = devm_kzalloc(&pdev->dev, sizeof(*dst), GFP_KERNEL);
893 	if (dst == NULL) {
894 		dev_put(dev);
895 		ret = -ENOMEM;
896 		goto out;
897 	}
898 
899 	platform_set_drvdata(pdev, dst);
900 
901 	ret = dsa_setup_dst(dst, dev, &pdev->dev, pd);
902 	if (ret) {
903 		dev_put(dev);
904 		goto out;
905 	}
906 
907 	return 0;
908 
909 out:
910 	dsa_of_remove(&pdev->dev);
911 
912 	return ret;
913 }
914 
915 static void dsa_remove_dst(struct dsa_switch_tree *dst)
916 {
917 	int i;
918 
919 	dst->master_netdev->dsa_ptr = NULL;
920 
921 	/* If we used a tagging format that doesn't have an ethertype
922 	 * field, make sure that all packets from this point get sent
923 	 * without the tag and go through the regular receive path.
924 	 */
925 	wmb();
926 
927 	for (i = 0; i < dst->pd->nr_chips; i++) {
928 		struct dsa_switch *ds = dst->ds[i];
929 
930 		if (ds)
931 			dsa_switch_destroy(ds);
932 	}
933 
934 	dev_put(dst->master_netdev);
935 }
936 
937 static int dsa_remove(struct platform_device *pdev)
938 {
939 	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
940 
941 	dsa_remove_dst(dst);
942 	dsa_of_remove(&pdev->dev);
943 
944 	return 0;
945 }
946 
947 static void dsa_shutdown(struct platform_device *pdev)
948 {
949 }
950 
951 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
952 			  struct packet_type *pt, struct net_device *orig_dev)
953 {
954 	struct dsa_switch_tree *dst = dev->dsa_ptr;
955 
956 	if (unlikely(dst == NULL)) {
957 		kfree_skb(skb);
958 		return 0;
959 	}
960 
961 	return dst->rcv(skb, dev, pt, orig_dev);
962 }
963 
964 static struct packet_type dsa_pack_type __read_mostly = {
965 	.type	= cpu_to_be16(ETH_P_XDSA),
966 	.func	= dsa_switch_rcv,
967 };
968 
969 static struct notifier_block dsa_netdevice_nb __read_mostly = {
970 	.notifier_call	= dsa_slave_netdevice_event,
971 };
972 
973 #ifdef CONFIG_PM_SLEEP
974 static int dsa_suspend(struct device *d)
975 {
976 	struct platform_device *pdev = to_platform_device(d);
977 	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
978 	int i, ret = 0;
979 
980 	for (i = 0; i < dst->pd->nr_chips; i++) {
981 		struct dsa_switch *ds = dst->ds[i];
982 
983 		if (ds != NULL)
984 			ret = dsa_switch_suspend(ds);
985 	}
986 
987 	return ret;
988 }
989 
990 static int dsa_resume(struct device *d)
991 {
992 	struct platform_device *pdev = to_platform_device(d);
993 	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
994 	int i, ret = 0;
995 
996 	for (i = 0; i < dst->pd->nr_chips; i++) {
997 		struct dsa_switch *ds = dst->ds[i];
998 
999 		if (ds != NULL)
1000 			ret = dsa_switch_resume(ds);
1001 	}
1002 
1003 	return ret;
1004 }
1005 #endif
1006 
1007 static SIMPLE_DEV_PM_OPS(dsa_pm_ops, dsa_suspend, dsa_resume);
1008 
1009 static const struct of_device_id dsa_of_match_table[] = {
1010 	{ .compatible = "brcm,bcm7445-switch-v4.0" },
1011 	{ .compatible = "marvell,dsa", },
1012 	{}
1013 };
1014 MODULE_DEVICE_TABLE(of, dsa_of_match_table);
1015 
1016 static struct platform_driver dsa_driver = {
1017 	.probe		= dsa_probe,
1018 	.remove		= dsa_remove,
1019 	.shutdown	= dsa_shutdown,
1020 	.driver = {
1021 		.name	= "dsa",
1022 		.of_match_table = dsa_of_match_table,
1023 		.pm	= &dsa_pm_ops,
1024 	},
1025 };
1026 
1027 static int __init dsa_init_module(void)
1028 {
1029 	int rc;
1030 
1031 	register_netdevice_notifier(&dsa_netdevice_nb);
1032 
1033 	rc = platform_driver_register(&dsa_driver);
1034 	if (rc)
1035 		return rc;
1036 
1037 	dev_add_pack(&dsa_pack_type);
1038 
1039 	return 0;
1040 }
1041 module_init(dsa_init_module);
1042 
1043 static void __exit dsa_cleanup_module(void)
1044 {
1045 	unregister_netdevice_notifier(&dsa_netdevice_nb);
1046 	dev_remove_pack(&dsa_pack_type);
1047 	platform_driver_unregister(&dsa_driver);
1048 }
1049 module_exit(dsa_cleanup_module);
1050 
1051 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
1052 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
1053 MODULE_LICENSE("GPL");
1054 MODULE_ALIAS("platform:dsa");
1055