xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision 2326f3cd)
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 void sfp_quirk_ubnt_uf_instant(const struct sfp_eeprom_id *id,
48 				      unsigned long *modes)
49 {
50 	/* Ubiquiti U-Fiber Instant module claims that support all transceiver
51 	 * types including 10G Ethernet which is not truth. So clear all claimed
52 	 * modes and set only one mode which module supports: 1000baseX_Full.
53 	 */
54 	phylink_zero(modes);
55 	phylink_set(modes, 1000baseX_Full);
56 }
57 
58 static const struct sfp_quirk sfp_quirks[] = {
59 	{
60 		// Alcatel Lucent G-010S-P can operate at 2500base-X, but
61 		// incorrectly report 2500MBd NRZ in their EEPROM
62 		.vendor = "ALCATELLUCENT",
63 		.part = "G010SP",
64 		.modes = sfp_quirk_2500basex,
65 	}, {
66 		// Alcatel Lucent G-010S-A can operate at 2500base-X, but
67 		// report 3.2GBd NRZ in their EEPROM
68 		.vendor = "ALCATELLUCENT",
69 		.part = "3FE46541AA",
70 		.modes = sfp_quirk_2500basex,
71 	}, {
72 		// Huawei MA5671A can operate at 2500base-X, but report 1.2GBd
73 		// NRZ in their EEPROM
74 		.vendor = "HUAWEI",
75 		.part = "MA5671A",
76 		.modes = sfp_quirk_2500basex,
77 	}, {
78 		.vendor = "UBNT",
79 		.part = "UF-INSTANT",
80 		.modes = sfp_quirk_ubnt_uf_instant,
81 	},
82 };
83 
84 static size_t sfp_strlen(const char *str, size_t maxlen)
85 {
86 	size_t size, i;
87 
88 	/* Trailing characters should be filled with space chars */
89 	for (i = 0, size = 0; i < maxlen; i++)
90 		if (str[i] != ' ')
91 			size = i + 1;
92 
93 	return size;
94 }
95 
96 static bool sfp_match(const char *qs, const char *str, size_t len)
97 {
98 	if (!qs)
99 		return true;
100 	if (strlen(qs) != len)
101 		return false;
102 	return !strncmp(qs, str, len);
103 }
104 
105 static const struct sfp_quirk *sfp_lookup_quirk(const struct sfp_eeprom_id *id)
106 {
107 	const struct sfp_quirk *q;
108 	unsigned int i;
109 	size_t vs, ps;
110 
111 	vs = sfp_strlen(id->base.vendor_name, ARRAY_SIZE(id->base.vendor_name));
112 	ps = sfp_strlen(id->base.vendor_pn, ARRAY_SIZE(id->base.vendor_pn));
113 
114 	for (i = 0, q = sfp_quirks; i < ARRAY_SIZE(sfp_quirks); i++, q++)
115 		if (sfp_match(q->vendor, id->base.vendor_name, vs) &&
116 		    sfp_match(q->part, id->base.vendor_pn, ps))
117 			return q;
118 
119 	return NULL;
120 }
121 
122 /**
123  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
124  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
125  * @id: a pointer to the module's &struct sfp_eeprom_id
126  * @support: optional pointer to an array of unsigned long for the
127  *   ethtool support mask
128  *
129  * Parse the EEPROM identification given in @id, and return one of
130  * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
131  * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
132  * the connector type.
133  *
134  * If the port type is not known, returns %PORT_OTHER.
135  */
136 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
137 		   unsigned long *support)
138 {
139 	int port;
140 
141 	/* port is the physical connector, set this from the connector field. */
142 	switch (id->base.connector) {
143 	case SFF8024_CONNECTOR_SC:
144 	case SFF8024_CONNECTOR_FIBERJACK:
145 	case SFF8024_CONNECTOR_LC:
146 	case SFF8024_CONNECTOR_MT_RJ:
147 	case SFF8024_CONNECTOR_MU:
148 	case SFF8024_CONNECTOR_OPTICAL_PIGTAIL:
149 	case SFF8024_CONNECTOR_MPO_1X12:
150 	case SFF8024_CONNECTOR_MPO_2X16:
151 		port = PORT_FIBRE;
152 		break;
153 
154 	case SFF8024_CONNECTOR_RJ45:
155 		port = PORT_TP;
156 		break;
157 
158 	case SFF8024_CONNECTOR_COPPER_PIGTAIL:
159 		port = PORT_DA;
160 		break;
161 
162 	case SFF8024_CONNECTOR_UNSPEC:
163 		if (id->base.e1000_base_t) {
164 			port = PORT_TP;
165 			break;
166 		}
167 		fallthrough;
168 	case SFF8024_CONNECTOR_SG: /* guess */
169 	case SFF8024_CONNECTOR_HSSDC_II:
170 	case SFF8024_CONNECTOR_NOSEPARATE:
171 	case SFF8024_CONNECTOR_MXC_2X16:
172 		port = PORT_OTHER;
173 		break;
174 	default:
175 		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
176 			 id->base.connector);
177 		port = PORT_OTHER;
178 		break;
179 	}
180 
181 	if (support) {
182 		switch (port) {
183 		case PORT_FIBRE:
184 			phylink_set(support, FIBRE);
185 			break;
186 
187 		case PORT_TP:
188 			phylink_set(support, TP);
189 			break;
190 		}
191 	}
192 
193 	return port;
194 }
195 EXPORT_SYMBOL_GPL(sfp_parse_port);
196 
197 /**
198  * sfp_may_have_phy() - indicate whether the module may have a PHY
199  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
200  * @id: a pointer to the module's &struct sfp_eeprom_id
201  *
202  * Parse the EEPROM identification given in @id, and return whether
203  * this module may have a PHY.
204  */
205 bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
206 {
207 	if (id->base.e1000_base_t)
208 		return true;
209 
210 	if (id->base.phys_id != SFF8024_ID_DWDM_SFP) {
211 		switch (id->base.extended_cc) {
212 		case SFF8024_ECC_10GBASE_T_SFI:
213 		case SFF8024_ECC_10GBASE_T_SR:
214 		case SFF8024_ECC_5GBASE_T:
215 		case SFF8024_ECC_2_5GBASE_T:
216 			return true;
217 		}
218 	}
219 
220 	return false;
221 }
222 EXPORT_SYMBOL_GPL(sfp_may_have_phy);
223 
224 /**
225  * sfp_parse_support() - Parse the eeprom id for supported link modes
226  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
227  * @id: a pointer to the module's &struct sfp_eeprom_id
228  * @support: pointer to an array of unsigned long for the ethtool support mask
229  *
230  * Parse the EEPROM identification information and derive the supported
231  * ethtool link modes for the module.
232  */
233 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
234 		       unsigned long *support)
235 {
236 	unsigned int br_min, br_nom, br_max;
237 	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
238 
239 	/* Decode the bitrate information to MBd */
240 	br_min = br_nom = br_max = 0;
241 	if (id->base.br_nominal) {
242 		if (id->base.br_nominal != 255) {
243 			br_nom = id->base.br_nominal * 100;
244 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
245 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
246 		} else if (id->ext.br_max) {
247 			br_nom = 250 * id->ext.br_max;
248 			br_max = br_nom + br_nom * id->ext.br_min / 100;
249 			br_min = br_nom - br_nom * id->ext.br_min / 100;
250 		}
251 
252 		/* When using passive cables, in case neither BR,min nor BR,max
253 		 * are specified, set br_min to 0 as the nominal value is then
254 		 * used as the maximum.
255 		 */
256 		if (br_min == br_max && id->base.sfp_ct_passive)
257 			br_min = 0;
258 	}
259 
260 	/* Set ethtool support from the compliance fields. */
261 	if (id->base.e10g_base_sr)
262 		phylink_set(modes, 10000baseSR_Full);
263 	if (id->base.e10g_base_lr)
264 		phylink_set(modes, 10000baseLR_Full);
265 	if (id->base.e10g_base_lrm)
266 		phylink_set(modes, 10000baseLRM_Full);
267 	if (id->base.e10g_base_er)
268 		phylink_set(modes, 10000baseER_Full);
269 	if (id->base.e1000_base_sx ||
270 	    id->base.e1000_base_lx ||
271 	    id->base.e1000_base_cx)
272 		phylink_set(modes, 1000baseX_Full);
273 	if (id->base.e1000_base_t) {
274 		phylink_set(modes, 1000baseT_Half);
275 		phylink_set(modes, 1000baseT_Full);
276 	}
277 
278 	/* 1000Base-PX or 1000Base-BX10 */
279 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
280 	    br_min <= 1300 && br_max >= 1200)
281 		phylink_set(modes, 1000baseX_Full);
282 
283 	/* 100Base-FX, 100Base-LX, 100Base-PX, 100Base-BX10 */
284 	if (id->base.e100_base_fx || id->base.e100_base_lx)
285 		phylink_set(modes, 100baseFX_Full);
286 	if ((id->base.e_base_px || id->base.e_base_bx10) && br_nom == 100)
287 		phylink_set(modes, 100baseFX_Full);
288 
289 	/* For active or passive cables, select the link modes
290 	 * based on the bit rates and the cable compliance bytes.
291 	 */
292 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
293 		/* This may look odd, but some manufacturers use 12000MBd */
294 		if (br_min <= 12000 && br_max >= 10300)
295 			phylink_set(modes, 10000baseCR_Full);
296 		if (br_min <= 3200 && br_max >= 3100)
297 			phylink_set(modes, 2500baseX_Full);
298 		if (br_min <= 1300 && br_max >= 1200)
299 			phylink_set(modes, 1000baseX_Full);
300 	}
301 	if (id->base.sfp_ct_passive) {
302 		if (id->base.passive.sff8431_app_e)
303 			phylink_set(modes, 10000baseCR_Full);
304 	}
305 	if (id->base.sfp_ct_active) {
306 		if (id->base.active.sff8431_app_e ||
307 		    id->base.active.sff8431_lim) {
308 			phylink_set(modes, 10000baseCR_Full);
309 		}
310 	}
311 
312 	switch (id->base.extended_cc) {
313 	case SFF8024_ECC_UNSPEC:
314 		break;
315 	case SFF8024_ECC_100GBASE_SR4_25GBASE_SR:
316 		phylink_set(modes, 100000baseSR4_Full);
317 		phylink_set(modes, 25000baseSR_Full);
318 		break;
319 	case SFF8024_ECC_100GBASE_LR4_25GBASE_LR:
320 	case SFF8024_ECC_100GBASE_ER4_25GBASE_ER:
321 		phylink_set(modes, 100000baseLR4_ER4_Full);
322 		break;
323 	case SFF8024_ECC_100GBASE_CR4:
324 		phylink_set(modes, 100000baseCR4_Full);
325 		fallthrough;
326 	case SFF8024_ECC_25GBASE_CR_S:
327 	case SFF8024_ECC_25GBASE_CR_N:
328 		phylink_set(modes, 25000baseCR_Full);
329 		break;
330 	case SFF8024_ECC_10GBASE_T_SFI:
331 	case SFF8024_ECC_10GBASE_T_SR:
332 		phylink_set(modes, 10000baseT_Full);
333 		break;
334 	case SFF8024_ECC_5GBASE_T:
335 		phylink_set(modes, 5000baseT_Full);
336 		break;
337 	case SFF8024_ECC_2_5GBASE_T:
338 		phylink_set(modes, 2500baseT_Full);
339 		break;
340 	default:
341 		dev_warn(bus->sfp_dev,
342 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
343 			 id->base.extended_cc);
344 		break;
345 	}
346 
347 	/* For fibre channel SFP, derive possible BaseX modes */
348 	if (id->base.fc_speed_100 ||
349 	    id->base.fc_speed_200 ||
350 	    id->base.fc_speed_400) {
351 		if (id->base.br_nominal >= 31)
352 			phylink_set(modes, 2500baseX_Full);
353 		if (id->base.br_nominal >= 12)
354 			phylink_set(modes, 1000baseX_Full);
355 	}
356 
357 	/* If we haven't discovered any modes that this module supports, try
358 	 * the bitrate to determine supported modes. Some BiDi modules (eg,
359 	 * 1310nm/1550nm) are not 1000BASE-BX compliant due to the differing
360 	 * wavelengths, so do not set any transceiver bits.
361 	 *
362 	 * Do the same for modules supporting 2500BASE-X. Note that some
363 	 * modules use 2500Mbaud rather than 3100 or 3200Mbaud for
364 	 * 2500BASE-X, so we allow some slack here.
365 	 */
366 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS) && br_nom) {
367 		if (br_min <= 1300 && br_max >= 1200)
368 			phylink_set(modes, 1000baseX_Full);
369 		if (br_min <= 3200 && br_max >= 2500)
370 			phylink_set(modes, 2500baseX_Full);
371 	}
372 
373 	if (bus->sfp_quirk)
374 		bus->sfp_quirk->modes(id, modes);
375 
376 	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
377 
378 	phylink_set(support, Autoneg);
379 	phylink_set(support, Pause);
380 	phylink_set(support, Asym_Pause);
381 }
382 EXPORT_SYMBOL_GPL(sfp_parse_support);
383 
384 /**
385  * sfp_select_interface() - Select appropriate phy_interface_t mode
386  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
387  * @link_modes: ethtool link modes mask
388  *
389  * Derive the phy_interface_t mode for the SFP module from the link
390  * modes mask.
391  */
392 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
393 				     unsigned long *link_modes)
394 {
395 	if (phylink_test(link_modes, 25000baseCR_Full) ||
396 	    phylink_test(link_modes, 25000baseKR_Full) ||
397 	    phylink_test(link_modes, 25000baseSR_Full))
398 		return PHY_INTERFACE_MODE_25GBASER;
399 
400 	if (phylink_test(link_modes, 10000baseCR_Full) ||
401 	    phylink_test(link_modes, 10000baseSR_Full) ||
402 	    phylink_test(link_modes, 10000baseLR_Full) ||
403 	    phylink_test(link_modes, 10000baseLRM_Full) ||
404 	    phylink_test(link_modes, 10000baseER_Full) ||
405 	    phylink_test(link_modes, 10000baseT_Full))
406 		return PHY_INTERFACE_MODE_10GBASER;
407 
408 	if (phylink_test(link_modes, 5000baseT_Full))
409 		return PHY_INTERFACE_MODE_5GBASER;
410 
411 	if (phylink_test(link_modes, 2500baseX_Full))
412 		return PHY_INTERFACE_MODE_2500BASEX;
413 
414 	if (phylink_test(link_modes, 1000baseT_Half) ||
415 	    phylink_test(link_modes, 1000baseT_Full))
416 		return PHY_INTERFACE_MODE_SGMII;
417 
418 	if (phylink_test(link_modes, 1000baseX_Full))
419 		return PHY_INTERFACE_MODE_1000BASEX;
420 
421 	if (phylink_test(link_modes, 100baseFX_Full))
422 		return PHY_INTERFACE_MODE_100BASEX;
423 
424 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
425 
426 	return PHY_INTERFACE_MODE_NA;
427 }
428 EXPORT_SYMBOL_GPL(sfp_select_interface);
429 
430 static LIST_HEAD(sfp_buses);
431 static DEFINE_MUTEX(sfp_mutex);
432 
433 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
434 {
435 	return bus->registered ? bus->upstream_ops : NULL;
436 }
437 
438 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
439 {
440 	struct sfp_bus *sfp, *new, *found = NULL;
441 
442 	new = kzalloc(sizeof(*new), GFP_KERNEL);
443 
444 	mutex_lock(&sfp_mutex);
445 
446 	list_for_each_entry(sfp, &sfp_buses, node) {
447 		if (sfp->fwnode == fwnode) {
448 			kref_get(&sfp->kref);
449 			found = sfp;
450 			break;
451 		}
452 	}
453 
454 	if (!found && new) {
455 		kref_init(&new->kref);
456 		new->fwnode = fwnode;
457 		list_add(&new->node, &sfp_buses);
458 		found = new;
459 		new = NULL;
460 	}
461 
462 	mutex_unlock(&sfp_mutex);
463 
464 	kfree(new);
465 
466 	return found;
467 }
468 
469 static void sfp_bus_release(struct kref *kref)
470 {
471 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
472 
473 	list_del(&bus->node);
474 	mutex_unlock(&sfp_mutex);
475 	kfree(bus);
476 }
477 
478 /**
479  * sfp_bus_put() - put a reference on the &struct sfp_bus
480  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
481  *
482  * Put a reference on the &struct sfp_bus and free the underlying structure
483  * if this was the last reference.
484  */
485 void sfp_bus_put(struct sfp_bus *bus)
486 {
487 	if (bus)
488 		kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
489 }
490 EXPORT_SYMBOL_GPL(sfp_bus_put);
491 
492 static int sfp_register_bus(struct sfp_bus *bus)
493 {
494 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
495 	int ret;
496 
497 	if (ops) {
498 		if (ops->link_down)
499 			ops->link_down(bus->upstream);
500 		if (ops->connect_phy && bus->phydev) {
501 			ret = ops->connect_phy(bus->upstream, bus->phydev);
502 			if (ret)
503 				return ret;
504 		}
505 	}
506 	bus->registered = true;
507 	bus->socket_ops->attach(bus->sfp);
508 	if (bus->started)
509 		bus->socket_ops->start(bus->sfp);
510 	bus->upstream_ops->attach(bus->upstream, bus);
511 	return 0;
512 }
513 
514 static void sfp_unregister_bus(struct sfp_bus *bus)
515 {
516 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
517 
518 	if (bus->registered) {
519 		bus->upstream_ops->detach(bus->upstream, bus);
520 		if (bus->started)
521 			bus->socket_ops->stop(bus->sfp);
522 		bus->socket_ops->detach(bus->sfp);
523 		if (bus->phydev && ops && ops->disconnect_phy)
524 			ops->disconnect_phy(bus->upstream);
525 	}
526 	bus->registered = false;
527 }
528 
529 /**
530  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
531  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
532  * @modinfo: a &struct ethtool_modinfo
533  *
534  * Fill in the type and eeprom_len parameters in @modinfo for a module on
535  * the sfp bus specified by @bus.
536  *
537  * Returns 0 on success or a negative errno number.
538  */
539 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
540 {
541 	return bus->socket_ops->module_info(bus->sfp, modinfo);
542 }
543 EXPORT_SYMBOL_GPL(sfp_get_module_info);
544 
545 /**
546  * sfp_get_module_eeprom() - Read the SFP module EEPROM
547  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
548  * @ee: a &struct ethtool_eeprom
549  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
550  *
551  * Read the EEPROM as specified by the supplied @ee. See the documentation
552  * for &struct ethtool_eeprom for the region to be read.
553  *
554  * Returns 0 on success or a negative errno number.
555  */
556 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
557 			  u8 *data)
558 {
559 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
560 }
561 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
562 
563 /**
564  * sfp_get_module_eeprom_by_page() - Read a page from the SFP module EEPROM
565  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
566  * @page: a &struct ethtool_module_eeprom
567  * @extack: extack for reporting problems
568  *
569  * Read an EEPROM page as specified by the supplied @page. See the
570  * documentation for &struct ethtool_module_eeprom for the page to be read.
571  *
572  * Returns 0 on success or a negative errno number. More error
573  * information might be provided via extack
574  */
575 int sfp_get_module_eeprom_by_page(struct sfp_bus *bus,
576 				  const struct ethtool_module_eeprom *page,
577 				  struct netlink_ext_ack *extack)
578 {
579 	return bus->socket_ops->module_eeprom_by_page(bus->sfp, page, extack);
580 }
581 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom_by_page);
582 
583 /**
584  * sfp_upstream_start() - Inform the SFP that the network device is up
585  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
586  *
587  * Inform the SFP socket that the network device is now up, so that the
588  * module can be enabled by allowing TX_DISABLE to be deasserted. This
589  * should be called from the network device driver's &struct net_device_ops
590  * ndo_open() method.
591  */
592 void sfp_upstream_start(struct sfp_bus *bus)
593 {
594 	if (bus->registered)
595 		bus->socket_ops->start(bus->sfp);
596 	bus->started = true;
597 }
598 EXPORT_SYMBOL_GPL(sfp_upstream_start);
599 
600 /**
601  * sfp_upstream_stop() - Inform the SFP that the network device is down
602  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
603  *
604  * Inform the SFP socket that the network device is now up, so that the
605  * module can be disabled by asserting TX_DISABLE, disabling the laser
606  * in optical modules. This should be called from the network device
607  * driver's &struct net_device_ops ndo_stop() method.
608  */
609 void sfp_upstream_stop(struct sfp_bus *bus)
610 {
611 	if (bus->registered)
612 		bus->socket_ops->stop(bus->sfp);
613 	bus->started = false;
614 }
615 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
616 
617 static void sfp_upstream_clear(struct sfp_bus *bus)
618 {
619 	bus->upstream_ops = NULL;
620 	bus->upstream = NULL;
621 }
622 
623 /**
624  * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
625  * @fwnode: firmware node for the parent device (MAC or PHY)
626  *
627  * Parse the parent device's firmware node for a SFP bus, and locate
628  * the sfp_bus structure, incrementing its reference count.  This must
629  * be put via sfp_bus_put() when done.
630  *
631  * Returns:
632  *	- on success, a pointer to the sfp_bus structure,
633  *	- %NULL if no SFP is specified,
634  *	- on failure, an error pointer value:
635  *
636  *	- corresponding to the errors detailed for
637  *	  fwnode_property_get_reference_args().
638  *	- %-ENOMEM if we failed to allocate the bus.
639  *	- an error from the upstream's connect_phy() method.
640  */
641 struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
642 {
643 	struct fwnode_reference_args ref;
644 	struct sfp_bus *bus;
645 	int ret;
646 
647 	ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
648 						 0, 0, &ref);
649 	if (ret == -ENOENT)
650 		return NULL;
651 	else if (ret < 0)
652 		return ERR_PTR(ret);
653 
654 	bus = sfp_bus_get(ref.fwnode);
655 	fwnode_handle_put(ref.fwnode);
656 	if (!bus)
657 		return ERR_PTR(-ENOMEM);
658 
659 	return bus;
660 }
661 EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
662 
663 /**
664  * sfp_bus_add_upstream() - parse and register the neighbouring device
665  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
666  * @upstream: the upstream private data
667  * @ops: the upstream's &struct sfp_upstream_ops
668  *
669  * Add upstream driver for the SFP bus, and if the bus is complete, register
670  * the SFP bus using sfp_register_upstream().  This takes a reference on the
671  * bus, so it is safe to put the bus after this call.
672  *
673  * Returns:
674  *	- on success, a pointer to the sfp_bus structure,
675  *	- %NULL if no SFP is specified,
676  *	- on failure, an error pointer value:
677  *
678  *	- corresponding to the errors detailed for
679  *	  fwnode_property_get_reference_args().
680  *	- %-ENOMEM if we failed to allocate the bus.
681  *	- an error from the upstream's connect_phy() method.
682  */
683 int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
684 			 const struct sfp_upstream_ops *ops)
685 {
686 	int ret;
687 
688 	/* If no bus, return success */
689 	if (!bus)
690 		return 0;
691 
692 	rtnl_lock();
693 	kref_get(&bus->kref);
694 	bus->upstream_ops = ops;
695 	bus->upstream = upstream;
696 
697 	if (bus->sfp) {
698 		ret = sfp_register_bus(bus);
699 		if (ret)
700 			sfp_upstream_clear(bus);
701 	} else {
702 		ret = 0;
703 	}
704 	rtnl_unlock();
705 
706 	if (ret)
707 		sfp_bus_put(bus);
708 
709 	return ret;
710 }
711 EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
712 
713 /**
714  * sfp_bus_del_upstream() - Delete a sfp bus
715  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
716  *
717  * Delete a previously registered upstream connection for the SFP
718  * module. @bus should have been added by sfp_bus_add_upstream().
719  */
720 void sfp_bus_del_upstream(struct sfp_bus *bus)
721 {
722 	if (bus) {
723 		rtnl_lock();
724 		if (bus->sfp)
725 			sfp_unregister_bus(bus);
726 		sfp_upstream_clear(bus);
727 		rtnl_unlock();
728 
729 		sfp_bus_put(bus);
730 	}
731 }
732 EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
733 
734 /* Socket driver entry points */
735 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
736 {
737 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
738 	int ret = 0;
739 
740 	if (ops && ops->connect_phy)
741 		ret = ops->connect_phy(bus->upstream, phydev);
742 
743 	if (ret == 0)
744 		bus->phydev = phydev;
745 
746 	return ret;
747 }
748 EXPORT_SYMBOL_GPL(sfp_add_phy);
749 
750 void sfp_remove_phy(struct sfp_bus *bus)
751 {
752 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
753 
754 	if (ops && ops->disconnect_phy)
755 		ops->disconnect_phy(bus->upstream);
756 	bus->phydev = NULL;
757 }
758 EXPORT_SYMBOL_GPL(sfp_remove_phy);
759 
760 void sfp_link_up(struct sfp_bus *bus)
761 {
762 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
763 
764 	if (ops && ops->link_up)
765 		ops->link_up(bus->upstream);
766 }
767 EXPORT_SYMBOL_GPL(sfp_link_up);
768 
769 void sfp_link_down(struct sfp_bus *bus)
770 {
771 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
772 
773 	if (ops && ops->link_down)
774 		ops->link_down(bus->upstream);
775 }
776 EXPORT_SYMBOL_GPL(sfp_link_down);
777 
778 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
779 {
780 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
781 	int ret = 0;
782 
783 	bus->sfp_quirk = sfp_lookup_quirk(id);
784 
785 	if (ops && ops->module_insert)
786 		ret = ops->module_insert(bus->upstream, id);
787 
788 	return ret;
789 }
790 EXPORT_SYMBOL_GPL(sfp_module_insert);
791 
792 void sfp_module_remove(struct sfp_bus *bus)
793 {
794 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
795 
796 	if (ops && ops->module_remove)
797 		ops->module_remove(bus->upstream);
798 
799 	bus->sfp_quirk = NULL;
800 }
801 EXPORT_SYMBOL_GPL(sfp_module_remove);
802 
803 int sfp_module_start(struct sfp_bus *bus)
804 {
805 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
806 	int ret = 0;
807 
808 	if (ops && ops->module_start)
809 		ret = ops->module_start(bus->upstream);
810 
811 	return ret;
812 }
813 EXPORT_SYMBOL_GPL(sfp_module_start);
814 
815 void sfp_module_stop(struct sfp_bus *bus)
816 {
817 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
818 
819 	if (ops && ops->module_stop)
820 		ops->module_stop(bus->upstream);
821 }
822 EXPORT_SYMBOL_GPL(sfp_module_stop);
823 
824 static void sfp_socket_clear(struct sfp_bus *bus)
825 {
826 	bus->sfp_dev = NULL;
827 	bus->sfp = NULL;
828 	bus->socket_ops = NULL;
829 }
830 
831 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
832 				    const struct sfp_socket_ops *ops)
833 {
834 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
835 	int ret = 0;
836 
837 	if (bus) {
838 		rtnl_lock();
839 		bus->sfp_dev = dev;
840 		bus->sfp = sfp;
841 		bus->socket_ops = ops;
842 
843 		if (bus->upstream_ops) {
844 			ret = sfp_register_bus(bus);
845 			if (ret)
846 				sfp_socket_clear(bus);
847 		}
848 		rtnl_unlock();
849 	}
850 
851 	if (ret) {
852 		sfp_bus_put(bus);
853 		bus = NULL;
854 	}
855 
856 	return bus;
857 }
858 EXPORT_SYMBOL_GPL(sfp_register_socket);
859 
860 void sfp_unregister_socket(struct sfp_bus *bus)
861 {
862 	rtnl_lock();
863 	if (bus->upstream_ops)
864 		sfp_unregister_bus(bus);
865 	sfp_socket_clear(bus);
866 	rtnl_unlock();
867 
868 	sfp_bus_put(bus);
869 }
870 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
871