xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision f9834f18)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/export.h>
3 #include <linux/kref.h>
4 #include <linux/list.h>
5 #include <linux/mutex.h>
6 #include <linux/phylink.h>
7 #include <linux/property.h>
8 #include <linux/rtnetlink.h>
9 #include <linux/slab.h>
10 
11 #include "sfp.h"
12 
13 struct sfp_quirk {
14 	const char *vendor;
15 	const char *part;
16 	void (*modes)(const struct sfp_eeprom_id *id, unsigned long *modes);
17 };
18 
19 /**
20  * struct sfp_bus - internal representation of a sfp bus
21  */
22 struct sfp_bus {
23 	/* private: */
24 	struct kref kref;
25 	struct list_head node;
26 	struct fwnode_handle *fwnode;
27 
28 	const struct sfp_socket_ops *socket_ops;
29 	struct device *sfp_dev;
30 	struct sfp *sfp;
31 	const struct sfp_quirk *sfp_quirk;
32 
33 	const struct sfp_upstream_ops *upstream_ops;
34 	void *upstream;
35 	struct phy_device *phydev;
36 
37 	bool registered;
38 	bool started;
39 };
40 
41 static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id,
42 				unsigned long *modes)
43 {
44 	phylink_set(modes, 2500baseX_Full);
45 }
46 
47 static const struct sfp_quirk sfp_quirks[] = {
48 	{
49 		// Alcatel Lucent G-010S-P can operate at 2500base-X, but
50 		// incorrectly report 2500MBd NRZ in their EEPROM
51 		.vendor = "ALCATELLUCENT",
52 		.part = "G010SP",
53 		.modes = sfp_quirk_2500basex,
54 	}, {
55 		// Alcatel Lucent G-010S-A can operate at 2500base-X, but
56 		// report 3.2GBd NRZ in their EEPROM
57 		.vendor = "ALCATELLUCENT",
58 		.part = "3FE46541AA",
59 		.modes = sfp_quirk_2500basex,
60 	}, {
61 		// Huawei MA5671A can operate at 2500base-X, but report 1.2GBd
62 		// NRZ in their EEPROM
63 		.vendor = "HUAWEI",
64 		.part = "MA5671A",
65 		.modes = sfp_quirk_2500basex,
66 	},
67 };
68 
69 static size_t sfp_strlen(const char *str, size_t maxlen)
70 {
71 	size_t size, i;
72 
73 	/* Trailing characters should be filled with space chars */
74 	for (i = 0, size = 0; i < maxlen; i++)
75 		if (str[i] != ' ')
76 			size = i + 1;
77 
78 	return size;
79 }
80 
81 static bool sfp_match(const char *qs, const char *str, size_t len)
82 {
83 	if (!qs)
84 		return true;
85 	if (strlen(qs) != len)
86 		return false;
87 	return !strncmp(qs, str, len);
88 }
89 
90 static const struct sfp_quirk *sfp_lookup_quirk(const struct sfp_eeprom_id *id)
91 {
92 	const struct sfp_quirk *q;
93 	unsigned int i;
94 	size_t vs, ps;
95 
96 	vs = sfp_strlen(id->base.vendor_name, ARRAY_SIZE(id->base.vendor_name));
97 	ps = sfp_strlen(id->base.vendor_pn, ARRAY_SIZE(id->base.vendor_pn));
98 
99 	for (i = 0, q = sfp_quirks; i < ARRAY_SIZE(sfp_quirks); i++, q++)
100 		if (sfp_match(q->vendor, id->base.vendor_name, vs) &&
101 		    sfp_match(q->part, id->base.vendor_pn, ps))
102 			return q;
103 
104 	return NULL;
105 }
106 
107 /**
108  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
109  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
110  * @id: a pointer to the module's &struct sfp_eeprom_id
111  * @support: optional pointer to an array of unsigned long for the
112  *   ethtool support mask
113  *
114  * Parse the EEPROM identification given in @id, and return one of
115  * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
116  * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
117  * the connector type.
118  *
119  * If the port type is not known, returns %PORT_OTHER.
120  */
121 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
122 		   unsigned long *support)
123 {
124 	int port;
125 
126 	/* port is the physical connector, set this from the connector field. */
127 	switch (id->base.connector) {
128 	case SFF8024_CONNECTOR_SC:
129 	case SFF8024_CONNECTOR_FIBERJACK:
130 	case SFF8024_CONNECTOR_LC:
131 	case SFF8024_CONNECTOR_MT_RJ:
132 	case SFF8024_CONNECTOR_MU:
133 	case SFF8024_CONNECTOR_OPTICAL_PIGTAIL:
134 	case SFF8024_CONNECTOR_MPO_1X12:
135 	case SFF8024_CONNECTOR_MPO_2X16:
136 		port = PORT_FIBRE;
137 		break;
138 
139 	case SFF8024_CONNECTOR_RJ45:
140 		port = PORT_TP;
141 		break;
142 
143 	case SFF8024_CONNECTOR_COPPER_PIGTAIL:
144 		port = PORT_DA;
145 		break;
146 
147 	case SFF8024_CONNECTOR_UNSPEC:
148 		if (id->base.e1000_base_t) {
149 			port = PORT_TP;
150 			break;
151 		}
152 		/* fallthrough */
153 	case SFF8024_CONNECTOR_SG: /* guess */
154 	case SFF8024_CONNECTOR_HSSDC_II:
155 	case SFF8024_CONNECTOR_NOSEPARATE:
156 	case SFF8024_CONNECTOR_MXC_2X16:
157 		port = PORT_OTHER;
158 		break;
159 	default:
160 		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
161 			 id->base.connector);
162 		port = PORT_OTHER;
163 		break;
164 	}
165 
166 	if (support) {
167 		switch (port) {
168 		case PORT_FIBRE:
169 			phylink_set(support, FIBRE);
170 			break;
171 
172 		case PORT_TP:
173 			phylink_set(support, TP);
174 			break;
175 		}
176 	}
177 
178 	return port;
179 }
180 EXPORT_SYMBOL_GPL(sfp_parse_port);
181 
182 /**
183  * sfp_may_have_phy() - indicate whether the module may have a PHY
184  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
185  * @id: a pointer to the module's &struct sfp_eeprom_id
186  *
187  * Parse the EEPROM identification given in @id, and return whether
188  * this module may have a PHY.
189  */
190 bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
191 {
192 	if (id->base.e1000_base_t)
193 		return true;
194 
195 	if (id->base.phys_id != SFF8024_ID_DWDM_SFP) {
196 		switch (id->base.extended_cc) {
197 		case SFF8024_ECC_10GBASE_T_SFI:
198 		case SFF8024_ECC_10GBASE_T_SR:
199 		case SFF8024_ECC_5GBASE_T:
200 		case SFF8024_ECC_2_5GBASE_T:
201 			return true;
202 		}
203 	}
204 
205 	return false;
206 }
207 EXPORT_SYMBOL_GPL(sfp_may_have_phy);
208 
209 /**
210  * sfp_parse_support() - Parse the eeprom id for supported link modes
211  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
212  * @id: a pointer to the module's &struct sfp_eeprom_id
213  * @support: pointer to an array of unsigned long for the ethtool support mask
214  *
215  * Parse the EEPROM identification information and derive the supported
216  * ethtool link modes for the module.
217  */
218 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
219 		       unsigned long *support)
220 {
221 	unsigned int br_min, br_nom, br_max;
222 	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
223 
224 	/* Decode the bitrate information to MBd */
225 	br_min = br_nom = br_max = 0;
226 	if (id->base.br_nominal) {
227 		if (id->base.br_nominal != 255) {
228 			br_nom = id->base.br_nominal * 100;
229 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
230 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
231 		} else if (id->ext.br_max) {
232 			br_nom = 250 * id->ext.br_max;
233 			br_max = br_nom + br_nom * id->ext.br_min / 100;
234 			br_min = br_nom - br_nom * id->ext.br_min / 100;
235 		}
236 
237 		/* When using passive cables, in case neither BR,min nor BR,max
238 		 * are specified, set br_min to 0 as the nominal value is then
239 		 * used as the maximum.
240 		 */
241 		if (br_min == br_max && id->base.sfp_ct_passive)
242 			br_min = 0;
243 	}
244 
245 	/* Set ethtool support from the compliance fields. */
246 	if (id->base.e10g_base_sr)
247 		phylink_set(modes, 10000baseSR_Full);
248 	if (id->base.e10g_base_lr)
249 		phylink_set(modes, 10000baseLR_Full);
250 	if (id->base.e10g_base_lrm)
251 		phylink_set(modes, 10000baseLRM_Full);
252 	if (id->base.e10g_base_er)
253 		phylink_set(modes, 10000baseER_Full);
254 	if (id->base.e1000_base_sx ||
255 	    id->base.e1000_base_lx ||
256 	    id->base.e1000_base_cx)
257 		phylink_set(modes, 1000baseX_Full);
258 	if (id->base.e1000_base_t) {
259 		phylink_set(modes, 1000baseT_Half);
260 		phylink_set(modes, 1000baseT_Full);
261 	}
262 
263 	/* 1000Base-PX or 1000Base-BX10 */
264 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
265 	    br_min <= 1300 && br_max >= 1200)
266 		phylink_set(modes, 1000baseX_Full);
267 
268 	/* For active or passive cables, select the link modes
269 	 * based on the bit rates and the cable compliance bytes.
270 	 */
271 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
272 		/* This may look odd, but some manufacturers use 12000MBd */
273 		if (br_min <= 12000 && br_max >= 10300)
274 			phylink_set(modes, 10000baseCR_Full);
275 		if (br_min <= 3200 && br_max >= 3100)
276 			phylink_set(modes, 2500baseX_Full);
277 		if (br_min <= 1300 && br_max >= 1200)
278 			phylink_set(modes, 1000baseX_Full);
279 	}
280 	if (id->base.sfp_ct_passive) {
281 		if (id->base.passive.sff8431_app_e)
282 			phylink_set(modes, 10000baseCR_Full);
283 	}
284 	if (id->base.sfp_ct_active) {
285 		if (id->base.active.sff8431_app_e ||
286 		    id->base.active.sff8431_lim) {
287 			phylink_set(modes, 10000baseCR_Full);
288 		}
289 	}
290 
291 	switch (id->base.extended_cc) {
292 	case SFF8024_ECC_UNSPEC:
293 		break;
294 	case SFF8024_ECC_100GBASE_SR4_25GBASE_SR:
295 		phylink_set(modes, 100000baseSR4_Full);
296 		phylink_set(modes, 25000baseSR_Full);
297 		break;
298 	case SFF8024_ECC_100GBASE_LR4_25GBASE_LR:
299 	case SFF8024_ECC_100GBASE_ER4_25GBASE_ER:
300 		phylink_set(modes, 100000baseLR4_ER4_Full);
301 		break;
302 	case SFF8024_ECC_100GBASE_CR4:
303 		phylink_set(modes, 100000baseCR4_Full);
304 		/* fallthrough */
305 	case SFF8024_ECC_25GBASE_CR_S:
306 	case SFF8024_ECC_25GBASE_CR_N:
307 		phylink_set(modes, 25000baseCR_Full);
308 		break;
309 	case SFF8024_ECC_10GBASE_T_SFI:
310 	case SFF8024_ECC_10GBASE_T_SR:
311 		phylink_set(modes, 10000baseT_Full);
312 		break;
313 	case SFF8024_ECC_5GBASE_T:
314 		phylink_set(modes, 5000baseT_Full);
315 		break;
316 	case SFF8024_ECC_2_5GBASE_T:
317 		phylink_set(modes, 2500baseT_Full);
318 		break;
319 	default:
320 		dev_warn(bus->sfp_dev,
321 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
322 			 id->base.extended_cc);
323 		break;
324 	}
325 
326 	/* For fibre channel SFP, derive possible BaseX modes */
327 	if (id->base.fc_speed_100 ||
328 	    id->base.fc_speed_200 ||
329 	    id->base.fc_speed_400) {
330 		if (id->base.br_nominal >= 31)
331 			phylink_set(modes, 2500baseX_Full);
332 		if (id->base.br_nominal >= 12)
333 			phylink_set(modes, 1000baseX_Full);
334 	}
335 
336 	/* If we haven't discovered any modes that this module supports, try
337 	 * the encoding and bitrate to determine supported modes. Some BiDi
338 	 * modules (eg, 1310nm/1550nm) are not 1000BASE-BX compliant due to
339 	 * the differing wavelengths, so do not set any transceiver bits.
340 	 */
341 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS)) {
342 		/* If the encoding and bit rate allows 1000baseX */
343 		if (id->base.encoding == SFF8024_ENCODING_8B10B && br_nom &&
344 		    br_min <= 1300 && br_max >= 1200)
345 			phylink_set(modes, 1000baseX_Full);
346 	}
347 
348 	if (bus->sfp_quirk)
349 		bus->sfp_quirk->modes(id, modes);
350 
351 	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
352 
353 	phylink_set(support, Autoneg);
354 	phylink_set(support, Pause);
355 	phylink_set(support, Asym_Pause);
356 }
357 EXPORT_SYMBOL_GPL(sfp_parse_support);
358 
359 /**
360  * sfp_select_interface() - Select appropriate phy_interface_t mode
361  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
362  * @link_modes: ethtool link modes mask
363  *
364  * Derive the phy_interface_t mode for the SFP module from the link
365  * modes mask.
366  */
367 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
368 				     unsigned long *link_modes)
369 {
370 	if (phylink_test(link_modes, 10000baseCR_Full) ||
371 	    phylink_test(link_modes, 10000baseSR_Full) ||
372 	    phylink_test(link_modes, 10000baseLR_Full) ||
373 	    phylink_test(link_modes, 10000baseLRM_Full) ||
374 	    phylink_test(link_modes, 10000baseER_Full) ||
375 	    phylink_test(link_modes, 10000baseT_Full))
376 		return PHY_INTERFACE_MODE_10GBASER;
377 
378 	if (phylink_test(link_modes, 2500baseX_Full))
379 		return PHY_INTERFACE_MODE_2500BASEX;
380 
381 	if (phylink_test(link_modes, 1000baseT_Half) ||
382 	    phylink_test(link_modes, 1000baseT_Full))
383 		return PHY_INTERFACE_MODE_SGMII;
384 
385 	if (phylink_test(link_modes, 1000baseX_Full))
386 		return PHY_INTERFACE_MODE_1000BASEX;
387 
388 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
389 
390 	return PHY_INTERFACE_MODE_NA;
391 }
392 EXPORT_SYMBOL_GPL(sfp_select_interface);
393 
394 static LIST_HEAD(sfp_buses);
395 static DEFINE_MUTEX(sfp_mutex);
396 
397 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
398 {
399 	return bus->registered ? bus->upstream_ops : NULL;
400 }
401 
402 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
403 {
404 	struct sfp_bus *sfp, *new, *found = NULL;
405 
406 	new = kzalloc(sizeof(*new), GFP_KERNEL);
407 
408 	mutex_lock(&sfp_mutex);
409 
410 	list_for_each_entry(sfp, &sfp_buses, node) {
411 		if (sfp->fwnode == fwnode) {
412 			kref_get(&sfp->kref);
413 			found = sfp;
414 			break;
415 		}
416 	}
417 
418 	if (!found && new) {
419 		kref_init(&new->kref);
420 		new->fwnode = fwnode;
421 		list_add(&new->node, &sfp_buses);
422 		found = new;
423 		new = NULL;
424 	}
425 
426 	mutex_unlock(&sfp_mutex);
427 
428 	kfree(new);
429 
430 	return found;
431 }
432 
433 static void sfp_bus_release(struct kref *kref)
434 {
435 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
436 
437 	list_del(&bus->node);
438 	mutex_unlock(&sfp_mutex);
439 	kfree(bus);
440 }
441 
442 /**
443  * sfp_bus_put() - put a reference on the &struct sfp_bus
444  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
445  *
446  * Put a reference on the &struct sfp_bus and free the underlying structure
447  * if this was the last reference.
448  */
449 void sfp_bus_put(struct sfp_bus *bus)
450 {
451 	if (bus)
452 		kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
453 }
454 EXPORT_SYMBOL_GPL(sfp_bus_put);
455 
456 static int sfp_register_bus(struct sfp_bus *bus)
457 {
458 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
459 	int ret;
460 
461 	if (ops) {
462 		if (ops->link_down)
463 			ops->link_down(bus->upstream);
464 		if (ops->connect_phy && bus->phydev) {
465 			ret = ops->connect_phy(bus->upstream, bus->phydev);
466 			if (ret)
467 				return ret;
468 		}
469 	}
470 	bus->registered = true;
471 	bus->socket_ops->attach(bus->sfp);
472 	if (bus->started)
473 		bus->socket_ops->start(bus->sfp);
474 	bus->upstream_ops->attach(bus->upstream, bus);
475 	return 0;
476 }
477 
478 static void sfp_unregister_bus(struct sfp_bus *bus)
479 {
480 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
481 
482 	if (bus->registered) {
483 		bus->upstream_ops->detach(bus->upstream, bus);
484 		if (bus->started)
485 			bus->socket_ops->stop(bus->sfp);
486 		bus->socket_ops->detach(bus->sfp);
487 		if (bus->phydev && ops && ops->disconnect_phy)
488 			ops->disconnect_phy(bus->upstream);
489 	}
490 	bus->registered = false;
491 }
492 
493 /**
494  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
495  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
496  * @modinfo: a &struct ethtool_modinfo
497  *
498  * Fill in the type and eeprom_len parameters in @modinfo for a module on
499  * the sfp bus specified by @bus.
500  *
501  * Returns 0 on success or a negative errno number.
502  */
503 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
504 {
505 	return bus->socket_ops->module_info(bus->sfp, modinfo);
506 }
507 EXPORT_SYMBOL_GPL(sfp_get_module_info);
508 
509 /**
510  * sfp_get_module_eeprom() - Read the SFP module EEPROM
511  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
512  * @ee: a &struct ethtool_eeprom
513  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
514  *
515  * Read the EEPROM as specified by the supplied @ee. See the documentation
516  * for &struct ethtool_eeprom for the region to be read.
517  *
518  * Returns 0 on success or a negative errno number.
519  */
520 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
521 			  u8 *data)
522 {
523 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
524 }
525 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
526 
527 /**
528  * sfp_upstream_start() - Inform the SFP that the network device is up
529  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
530  *
531  * Inform the SFP socket that the network device is now up, so that the
532  * module can be enabled by allowing TX_DISABLE to be deasserted. This
533  * should be called from the network device driver's &struct net_device_ops
534  * ndo_open() method.
535  */
536 void sfp_upstream_start(struct sfp_bus *bus)
537 {
538 	if (bus->registered)
539 		bus->socket_ops->start(bus->sfp);
540 	bus->started = true;
541 }
542 EXPORT_SYMBOL_GPL(sfp_upstream_start);
543 
544 /**
545  * sfp_upstream_stop() - Inform the SFP that the network device is down
546  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
547  *
548  * Inform the SFP socket that the network device is now up, so that the
549  * module can be disabled by asserting TX_DISABLE, disabling the laser
550  * in optical modules. This should be called from the network device
551  * driver's &struct net_device_ops ndo_stop() method.
552  */
553 void sfp_upstream_stop(struct sfp_bus *bus)
554 {
555 	if (bus->registered)
556 		bus->socket_ops->stop(bus->sfp);
557 	bus->started = false;
558 }
559 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
560 
561 static void sfp_upstream_clear(struct sfp_bus *bus)
562 {
563 	bus->upstream_ops = NULL;
564 	bus->upstream = NULL;
565 }
566 
567 /**
568  * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
569  * @fwnode: firmware node for the parent device (MAC or PHY)
570  *
571  * Parse the parent device's firmware node for a SFP bus, and locate
572  * the sfp_bus structure, incrementing its reference count.  This must
573  * be put via sfp_bus_put() when done.
574  *
575  * Returns: on success, a pointer to the sfp_bus structure,
576  *	    %NULL if no SFP is specified,
577  * 	    on failure, an error pointer value:
578  * 		corresponding to the errors detailed for
579  * 		fwnode_property_get_reference_args().
580  * 	        %-ENOMEM if we failed to allocate the bus.
581  *		an error from the upstream's connect_phy() method.
582  */
583 struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
584 {
585 	struct fwnode_reference_args ref;
586 	struct sfp_bus *bus;
587 	int ret;
588 
589 	ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
590 						 0, 0, &ref);
591 	if (ret == -ENOENT)
592 		return NULL;
593 	else if (ret < 0)
594 		return ERR_PTR(ret);
595 
596 	bus = sfp_bus_get(ref.fwnode);
597 	fwnode_handle_put(ref.fwnode);
598 	if (!bus)
599 		return ERR_PTR(-ENOMEM);
600 
601 	return bus;
602 }
603 EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
604 
605 /**
606  * sfp_bus_add_upstream() - parse and register the neighbouring device
607  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
608  * @upstream: the upstream private data
609  * @ops: the upstream's &struct sfp_upstream_ops
610  *
611  * Add upstream driver for the SFP bus, and if the bus is complete, register
612  * the SFP bus using sfp_register_upstream().  This takes a reference on the
613  * bus, so it is safe to put the bus after this call.
614  *
615  * Returns: on success, a pointer to the sfp_bus structure,
616  *	    %NULL if no SFP is specified,
617  * 	    on failure, an error pointer value:
618  * 		corresponding to the errors detailed for
619  * 		fwnode_property_get_reference_args().
620  * 	        %-ENOMEM if we failed to allocate the bus.
621  *		an error from the upstream's connect_phy() method.
622  */
623 int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
624 			 const struct sfp_upstream_ops *ops)
625 {
626 	int ret;
627 
628 	/* If no bus, return success */
629 	if (!bus)
630 		return 0;
631 
632 	rtnl_lock();
633 	kref_get(&bus->kref);
634 	bus->upstream_ops = ops;
635 	bus->upstream = upstream;
636 
637 	if (bus->sfp) {
638 		ret = sfp_register_bus(bus);
639 		if (ret)
640 			sfp_upstream_clear(bus);
641 	} else {
642 		ret = 0;
643 	}
644 	rtnl_unlock();
645 
646 	if (ret)
647 		sfp_bus_put(bus);
648 
649 	return ret;
650 }
651 EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
652 
653 /**
654  * sfp_bus_del_upstream() - Delete a sfp bus
655  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
656  *
657  * Delete a previously registered upstream connection for the SFP
658  * module. @bus should have been added by sfp_bus_add_upstream().
659  */
660 void sfp_bus_del_upstream(struct sfp_bus *bus)
661 {
662 	if (bus) {
663 		rtnl_lock();
664 		if (bus->sfp)
665 			sfp_unregister_bus(bus);
666 		sfp_upstream_clear(bus);
667 		rtnl_unlock();
668 
669 		sfp_bus_put(bus);
670 	}
671 }
672 EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
673 
674 /* Socket driver entry points */
675 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
676 {
677 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
678 	int ret = 0;
679 
680 	if (ops && ops->connect_phy)
681 		ret = ops->connect_phy(bus->upstream, phydev);
682 
683 	if (ret == 0)
684 		bus->phydev = phydev;
685 
686 	return ret;
687 }
688 EXPORT_SYMBOL_GPL(sfp_add_phy);
689 
690 void sfp_remove_phy(struct sfp_bus *bus)
691 {
692 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
693 
694 	if (ops && ops->disconnect_phy)
695 		ops->disconnect_phy(bus->upstream);
696 	bus->phydev = NULL;
697 }
698 EXPORT_SYMBOL_GPL(sfp_remove_phy);
699 
700 void sfp_link_up(struct sfp_bus *bus)
701 {
702 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
703 
704 	if (ops && ops->link_up)
705 		ops->link_up(bus->upstream);
706 }
707 EXPORT_SYMBOL_GPL(sfp_link_up);
708 
709 void sfp_link_down(struct sfp_bus *bus)
710 {
711 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
712 
713 	if (ops && ops->link_down)
714 		ops->link_down(bus->upstream);
715 }
716 EXPORT_SYMBOL_GPL(sfp_link_down);
717 
718 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
719 {
720 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
721 	int ret = 0;
722 
723 	bus->sfp_quirk = sfp_lookup_quirk(id);
724 
725 	if (ops && ops->module_insert)
726 		ret = ops->module_insert(bus->upstream, id);
727 
728 	return ret;
729 }
730 EXPORT_SYMBOL_GPL(sfp_module_insert);
731 
732 void sfp_module_remove(struct sfp_bus *bus)
733 {
734 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
735 
736 	if (ops && ops->module_remove)
737 		ops->module_remove(bus->upstream);
738 
739 	bus->sfp_quirk = NULL;
740 }
741 EXPORT_SYMBOL_GPL(sfp_module_remove);
742 
743 int sfp_module_start(struct sfp_bus *bus)
744 {
745 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
746 	int ret = 0;
747 
748 	if (ops && ops->module_start)
749 		ret = ops->module_start(bus->upstream);
750 
751 	return ret;
752 }
753 EXPORT_SYMBOL_GPL(sfp_module_start);
754 
755 void sfp_module_stop(struct sfp_bus *bus)
756 {
757 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
758 
759 	if (ops && ops->module_stop)
760 		ops->module_stop(bus->upstream);
761 }
762 EXPORT_SYMBOL_GPL(sfp_module_stop);
763 
764 static void sfp_socket_clear(struct sfp_bus *bus)
765 {
766 	bus->sfp_dev = NULL;
767 	bus->sfp = NULL;
768 	bus->socket_ops = NULL;
769 }
770 
771 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
772 				    const struct sfp_socket_ops *ops)
773 {
774 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
775 	int ret = 0;
776 
777 	if (bus) {
778 		rtnl_lock();
779 		bus->sfp_dev = dev;
780 		bus->sfp = sfp;
781 		bus->socket_ops = ops;
782 
783 		if (bus->upstream_ops) {
784 			ret = sfp_register_bus(bus);
785 			if (ret)
786 				sfp_socket_clear(bus);
787 		}
788 		rtnl_unlock();
789 	}
790 
791 	if (ret) {
792 		sfp_bus_put(bus);
793 		bus = NULL;
794 	}
795 
796 	return bus;
797 }
798 EXPORT_SYMBOL_GPL(sfp_register_socket);
799 
800 void sfp_unregister_socket(struct sfp_bus *bus)
801 {
802 	rtnl_lock();
803 	if (bus->upstream_ops)
804 		sfp_unregister_bus(bus);
805 	sfp_socket_clear(bus);
806 	rtnl_unlock();
807 
808 	sfp_bus_put(bus);
809 }
810 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
811