xref: /linux/drivers/net/phy/sfp-bus.c (revision 83439a0f1ce6a592f95e41338320b5f01b98a356)
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 /**
14  * struct sfp_bus - internal representation of a sfp bus
15  */
16 struct sfp_bus {
17 	/* private: */
18 	struct kref kref;
19 	struct list_head node;
20 	struct fwnode_handle *fwnode;
21 
22 	const struct sfp_socket_ops *socket_ops;
23 	struct device *sfp_dev;
24 	struct sfp *sfp;
25 	const struct sfp_quirk *sfp_quirk;
26 
27 	const struct sfp_upstream_ops *upstream_ops;
28 	void *upstream;
29 	struct phy_device *phydev;
30 
31 	bool registered;
32 	bool started;
33 };
34 
35 /**
36  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
37  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
38  * @id: a pointer to the module's &struct sfp_eeprom_id
39  * @support: optional pointer to an array of unsigned long for the
40  *   ethtool support mask
41  *
42  * Parse the EEPROM identification given in @id, and return one of
43  * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
44  * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
45  * the connector type.
46  *
47  * If the port type is not known, returns %PORT_OTHER.
48  */
49 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
50 		   unsigned long *support)
51 {
52 	int port;
53 
54 	/* port is the physical connector, set this from the connector field. */
55 	switch (id->base.connector) {
56 	case SFF8024_CONNECTOR_SC:
57 	case SFF8024_CONNECTOR_FIBERJACK:
58 	case SFF8024_CONNECTOR_LC:
59 	case SFF8024_CONNECTOR_MT_RJ:
60 	case SFF8024_CONNECTOR_MU:
61 	case SFF8024_CONNECTOR_OPTICAL_PIGTAIL:
62 	case SFF8024_CONNECTOR_MPO_1X12:
63 	case SFF8024_CONNECTOR_MPO_2X16:
64 		port = PORT_FIBRE;
65 		break;
66 
67 	case SFF8024_CONNECTOR_RJ45:
68 		port = PORT_TP;
69 		break;
70 
71 	case SFF8024_CONNECTOR_COPPER_PIGTAIL:
72 		port = PORT_DA;
73 		break;
74 
75 	case SFF8024_CONNECTOR_UNSPEC:
76 		if (id->base.e1000_base_t) {
77 			port = PORT_TP;
78 			break;
79 		}
80 		fallthrough;
81 	case SFF8024_CONNECTOR_SG: /* guess */
82 	case SFF8024_CONNECTOR_HSSDC_II:
83 	case SFF8024_CONNECTOR_NOSEPARATE:
84 	case SFF8024_CONNECTOR_MXC_2X16:
85 		port = PORT_OTHER;
86 		break;
87 	default:
88 		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
89 			 id->base.connector);
90 		port = PORT_OTHER;
91 		break;
92 	}
93 
94 	if (support) {
95 		switch (port) {
96 		case PORT_FIBRE:
97 			phylink_set(support, FIBRE);
98 			break;
99 
100 		case PORT_TP:
101 			phylink_set(support, TP);
102 			break;
103 		}
104 	}
105 
106 	return port;
107 }
108 EXPORT_SYMBOL_GPL(sfp_parse_port);
109 
110 /**
111  * sfp_may_have_phy() - indicate whether the module may have a PHY
112  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
113  * @id: a pointer to the module's &struct sfp_eeprom_id
114  *
115  * Parse the EEPROM identification given in @id, and return whether
116  * this module may have a PHY.
117  */
118 bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
119 {
120 	if (id->base.e1000_base_t)
121 		return true;
122 
123 	if (id->base.phys_id != SFF8024_ID_DWDM_SFP) {
124 		switch (id->base.extended_cc) {
125 		case SFF8024_ECC_10GBASE_T_SFI:
126 		case SFF8024_ECC_10GBASE_T_SR:
127 		case SFF8024_ECC_5GBASE_T:
128 		case SFF8024_ECC_2_5GBASE_T:
129 			return true;
130 		}
131 	}
132 
133 	return false;
134 }
135 EXPORT_SYMBOL_GPL(sfp_may_have_phy);
136 
137 /**
138  * sfp_parse_support() - Parse the eeprom id for supported link modes
139  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
140  * @id: a pointer to the module's &struct sfp_eeprom_id
141  * @support: pointer to an array of unsigned long for the ethtool support mask
142  * @interfaces: pointer to an array of unsigned long for phy interface modes
143  *		mask
144  *
145  * Parse the EEPROM identification information and derive the supported
146  * ethtool link modes for the module.
147  */
148 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
149 		       unsigned long *support, unsigned long *interfaces)
150 {
151 	unsigned int br_min, br_nom, br_max;
152 	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
153 
154 	/* Decode the bitrate information to MBd */
155 	br_min = br_nom = br_max = 0;
156 	if (id->base.br_nominal) {
157 		if (id->base.br_nominal != 255) {
158 			br_nom = id->base.br_nominal * 100;
159 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
160 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
161 		} else if (id->ext.br_max) {
162 			br_nom = 250 * id->ext.br_max;
163 			br_max = br_nom + br_nom * id->ext.br_min / 100;
164 			br_min = br_nom - br_nom * id->ext.br_min / 100;
165 		}
166 
167 		/* When using passive cables, in case neither BR,min nor BR,max
168 		 * are specified, set br_min to 0 as the nominal value is then
169 		 * used as the maximum.
170 		 */
171 		if (br_min == br_max && id->base.sfp_ct_passive)
172 			br_min = 0;
173 	}
174 
175 	/* Set ethtool support from the compliance fields. */
176 	if (id->base.e10g_base_sr) {
177 		phylink_set(modes, 10000baseSR_Full);
178 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
179 	}
180 	if (id->base.e10g_base_lr) {
181 		phylink_set(modes, 10000baseLR_Full);
182 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
183 	}
184 	if (id->base.e10g_base_lrm) {
185 		phylink_set(modes, 10000baseLRM_Full);
186 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
187 	}
188 	if (id->base.e10g_base_er) {
189 		phylink_set(modes, 10000baseER_Full);
190 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
191 	}
192 	if (id->base.e1000_base_sx ||
193 	    id->base.e1000_base_lx ||
194 	    id->base.e1000_base_cx) {
195 		phylink_set(modes, 1000baseX_Full);
196 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
197 	}
198 	if (id->base.e1000_base_t) {
199 		phylink_set(modes, 1000baseT_Half);
200 		phylink_set(modes, 1000baseT_Full);
201 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
202 		__set_bit(PHY_INTERFACE_MODE_SGMII, interfaces);
203 	}
204 
205 	/* 1000Base-PX or 1000Base-BX10 */
206 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
207 	    br_min <= 1300 && br_max >= 1200) {
208 		phylink_set(modes, 1000baseX_Full);
209 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
210 	}
211 
212 	/* 100Base-FX, 100Base-LX, 100Base-PX, 100Base-BX10 */
213 	if (id->base.e100_base_fx || id->base.e100_base_lx) {
214 		phylink_set(modes, 100baseFX_Full);
215 		__set_bit(PHY_INTERFACE_MODE_100BASEX, interfaces);
216 	}
217 	if ((id->base.e_base_px || id->base.e_base_bx10) && br_nom == 100) {
218 		phylink_set(modes, 100baseFX_Full);
219 		__set_bit(PHY_INTERFACE_MODE_100BASEX, interfaces);
220 	}
221 
222 	/* For active or passive cables, select the link modes
223 	 * based on the bit rates and the cable compliance bytes.
224 	 */
225 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
226 		/* This may look odd, but some manufacturers use 12000MBd */
227 		if (br_min <= 12000 && br_max >= 10300) {
228 			phylink_set(modes, 10000baseCR_Full);
229 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
230 		}
231 		if (br_min <= 3200 && br_max >= 3100) {
232 			phylink_set(modes, 2500baseX_Full);
233 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
234 		}
235 		if (br_min <= 1300 && br_max >= 1200) {
236 			phylink_set(modes, 1000baseX_Full);
237 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
238 		}
239 	}
240 	if (id->base.sfp_ct_passive) {
241 		if (id->base.passive.sff8431_app_e) {
242 			phylink_set(modes, 10000baseCR_Full);
243 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
244 		}
245 	}
246 	if (id->base.sfp_ct_active) {
247 		if (id->base.active.sff8431_app_e ||
248 		    id->base.active.sff8431_lim) {
249 			phylink_set(modes, 10000baseCR_Full);
250 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
251 		}
252 	}
253 
254 	switch (id->base.extended_cc) {
255 	case SFF8024_ECC_UNSPEC:
256 		break;
257 	case SFF8024_ECC_100GBASE_SR4_25GBASE_SR:
258 		phylink_set(modes, 100000baseSR4_Full);
259 		phylink_set(modes, 25000baseSR_Full);
260 		break;
261 	case SFF8024_ECC_100GBASE_LR4_25GBASE_LR:
262 	case SFF8024_ECC_100GBASE_ER4_25GBASE_ER:
263 		phylink_set(modes, 100000baseLR4_ER4_Full);
264 		break;
265 	case SFF8024_ECC_100GBASE_CR4:
266 		phylink_set(modes, 100000baseCR4_Full);
267 		fallthrough;
268 	case SFF8024_ECC_25GBASE_CR_S:
269 	case SFF8024_ECC_25GBASE_CR_N:
270 		phylink_set(modes, 25000baseCR_Full);
271 		break;
272 	case SFF8024_ECC_10GBASE_T_SFI:
273 	case SFF8024_ECC_10GBASE_T_SR:
274 		phylink_set(modes, 10000baseT_Full);
275 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
276 		break;
277 	case SFF8024_ECC_5GBASE_T:
278 		phylink_set(modes, 5000baseT_Full);
279 		break;
280 	case SFF8024_ECC_2_5GBASE_T:
281 		phylink_set(modes, 2500baseT_Full);
282 		__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
283 		break;
284 	default:
285 		dev_warn(bus->sfp_dev,
286 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
287 			 id->base.extended_cc);
288 		break;
289 	}
290 
291 	/* For fibre channel SFP, derive possible BaseX modes */
292 	if (id->base.fc_speed_100 ||
293 	    id->base.fc_speed_200 ||
294 	    id->base.fc_speed_400) {
295 		if (id->base.br_nominal >= 31) {
296 			phylink_set(modes, 2500baseX_Full);
297 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
298 		}
299 		if (id->base.br_nominal >= 12) {
300 			phylink_set(modes, 1000baseX_Full);
301 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
302 		}
303 	}
304 
305 	/* If we haven't discovered any modes that this module supports, try
306 	 * the bitrate to determine supported modes. Some BiDi modules (eg,
307 	 * 1310nm/1550nm) are not 1000BASE-BX compliant due to the differing
308 	 * wavelengths, so do not set any transceiver bits.
309 	 *
310 	 * Do the same for modules supporting 2500BASE-X. Note that some
311 	 * modules use 2500Mbaud rather than 3100 or 3200Mbaud for
312 	 * 2500BASE-X, so we allow some slack here.
313 	 */
314 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS) && br_nom) {
315 		if (br_min <= 1300 && br_max >= 1200) {
316 			phylink_set(modes, 1000baseX_Full);
317 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
318 		}
319 		if (br_min <= 3200 && br_max >= 2500) {
320 			phylink_set(modes, 2500baseX_Full);
321 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
322 		}
323 	}
324 
325 	if (bus->sfp_quirk && bus->sfp_quirk->modes)
326 		bus->sfp_quirk->modes(id, modes, interfaces);
327 
328 	linkmode_or(support, support, modes);
329 
330 	phylink_set(support, Autoneg);
331 	phylink_set(support, Pause);
332 	phylink_set(support, Asym_Pause);
333 }
334 EXPORT_SYMBOL_GPL(sfp_parse_support);
335 
336 /**
337  * sfp_select_interface() - Select appropriate phy_interface_t mode
338  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
339  * @link_modes: ethtool link modes mask
340  *
341  * Derive the phy_interface_t mode for the SFP module from the link
342  * modes mask.
343  */
344 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
345 				     unsigned long *link_modes)
346 {
347 	if (phylink_test(link_modes, 25000baseCR_Full) ||
348 	    phylink_test(link_modes, 25000baseKR_Full) ||
349 	    phylink_test(link_modes, 25000baseSR_Full))
350 		return PHY_INTERFACE_MODE_25GBASER;
351 
352 	if (phylink_test(link_modes, 10000baseCR_Full) ||
353 	    phylink_test(link_modes, 10000baseSR_Full) ||
354 	    phylink_test(link_modes, 10000baseLR_Full) ||
355 	    phylink_test(link_modes, 10000baseLRM_Full) ||
356 	    phylink_test(link_modes, 10000baseER_Full) ||
357 	    phylink_test(link_modes, 10000baseT_Full))
358 		return PHY_INTERFACE_MODE_10GBASER;
359 
360 	if (phylink_test(link_modes, 5000baseT_Full))
361 		return PHY_INTERFACE_MODE_5GBASER;
362 
363 	if (phylink_test(link_modes, 2500baseX_Full))
364 		return PHY_INTERFACE_MODE_2500BASEX;
365 
366 	if (phylink_test(link_modes, 1000baseT_Half) ||
367 	    phylink_test(link_modes, 1000baseT_Full))
368 		return PHY_INTERFACE_MODE_SGMII;
369 
370 	if (phylink_test(link_modes, 1000baseX_Full))
371 		return PHY_INTERFACE_MODE_1000BASEX;
372 
373 	if (phylink_test(link_modes, 100baseFX_Full))
374 		return PHY_INTERFACE_MODE_100BASEX;
375 
376 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
377 
378 	return PHY_INTERFACE_MODE_NA;
379 }
380 EXPORT_SYMBOL_GPL(sfp_select_interface);
381 
382 static LIST_HEAD(sfp_buses);
383 static DEFINE_MUTEX(sfp_mutex);
384 
385 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
386 {
387 	return bus->registered ? bus->upstream_ops : NULL;
388 }
389 
390 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
391 {
392 	struct sfp_bus *sfp, *new, *found = NULL;
393 
394 	new = kzalloc(sizeof(*new), GFP_KERNEL);
395 
396 	mutex_lock(&sfp_mutex);
397 
398 	list_for_each_entry(sfp, &sfp_buses, node) {
399 		if (sfp->fwnode == fwnode) {
400 			kref_get(&sfp->kref);
401 			found = sfp;
402 			break;
403 		}
404 	}
405 
406 	if (!found && new) {
407 		kref_init(&new->kref);
408 		new->fwnode = fwnode;
409 		list_add(&new->node, &sfp_buses);
410 		found = new;
411 		new = NULL;
412 	}
413 
414 	mutex_unlock(&sfp_mutex);
415 
416 	kfree(new);
417 
418 	return found;
419 }
420 
421 static void sfp_bus_release(struct kref *kref)
422 {
423 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
424 
425 	list_del(&bus->node);
426 	mutex_unlock(&sfp_mutex);
427 	kfree(bus);
428 }
429 
430 /**
431  * sfp_bus_put() - put a reference on the &struct sfp_bus
432  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
433  *
434  * Put a reference on the &struct sfp_bus and free the underlying structure
435  * if this was the last reference.
436  */
437 void sfp_bus_put(struct sfp_bus *bus)
438 {
439 	if (bus)
440 		kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
441 }
442 EXPORT_SYMBOL_GPL(sfp_bus_put);
443 
444 static int sfp_register_bus(struct sfp_bus *bus)
445 {
446 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
447 	int ret;
448 
449 	if (ops) {
450 		if (ops->link_down)
451 			ops->link_down(bus->upstream);
452 		if (ops->connect_phy && bus->phydev) {
453 			ret = ops->connect_phy(bus->upstream, bus->phydev);
454 			if (ret)
455 				return ret;
456 		}
457 	}
458 	bus->registered = true;
459 	bus->socket_ops->attach(bus->sfp);
460 	if (bus->started)
461 		bus->socket_ops->start(bus->sfp);
462 	bus->upstream_ops->attach(bus->upstream, bus);
463 	return 0;
464 }
465 
466 static void sfp_unregister_bus(struct sfp_bus *bus)
467 {
468 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
469 
470 	if (bus->registered) {
471 		bus->upstream_ops->detach(bus->upstream, bus);
472 		if (bus->started)
473 			bus->socket_ops->stop(bus->sfp);
474 		bus->socket_ops->detach(bus->sfp);
475 		if (bus->phydev && ops && ops->disconnect_phy)
476 			ops->disconnect_phy(bus->upstream);
477 	}
478 	bus->registered = false;
479 }
480 
481 /**
482  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
483  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
484  * @modinfo: a &struct ethtool_modinfo
485  *
486  * Fill in the type and eeprom_len parameters in @modinfo for a module on
487  * the sfp bus specified by @bus.
488  *
489  * Returns 0 on success or a negative errno number.
490  */
491 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
492 {
493 	return bus->socket_ops->module_info(bus->sfp, modinfo);
494 }
495 EXPORT_SYMBOL_GPL(sfp_get_module_info);
496 
497 /**
498  * sfp_get_module_eeprom() - Read the SFP module EEPROM
499  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
500  * @ee: a &struct ethtool_eeprom
501  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
502  *
503  * Read the EEPROM as specified by the supplied @ee. See the documentation
504  * for &struct ethtool_eeprom for the region to be read.
505  *
506  * Returns 0 on success or a negative errno number.
507  */
508 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
509 			  u8 *data)
510 {
511 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
512 }
513 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
514 
515 /**
516  * sfp_get_module_eeprom_by_page() - Read a page from the SFP module EEPROM
517  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
518  * @page: a &struct ethtool_module_eeprom
519  * @extack: extack for reporting problems
520  *
521  * Read an EEPROM page as specified by the supplied @page. See the
522  * documentation for &struct ethtool_module_eeprom for the page to be read.
523  *
524  * Returns 0 on success or a negative errno number. More error
525  * information might be provided via extack
526  */
527 int sfp_get_module_eeprom_by_page(struct sfp_bus *bus,
528 				  const struct ethtool_module_eeprom *page,
529 				  struct netlink_ext_ack *extack)
530 {
531 	return bus->socket_ops->module_eeprom_by_page(bus->sfp, page, extack);
532 }
533 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom_by_page);
534 
535 /**
536  * sfp_upstream_start() - Inform the SFP that the network device is up
537  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
538  *
539  * Inform the SFP socket that the network device is now up, so that the
540  * module can be enabled by allowing TX_DISABLE to be deasserted. This
541  * should be called from the network device driver's &struct net_device_ops
542  * ndo_open() method.
543  */
544 void sfp_upstream_start(struct sfp_bus *bus)
545 {
546 	if (bus->registered)
547 		bus->socket_ops->start(bus->sfp);
548 	bus->started = true;
549 }
550 EXPORT_SYMBOL_GPL(sfp_upstream_start);
551 
552 /**
553  * sfp_upstream_stop() - Inform the SFP that the network device is down
554  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
555  *
556  * Inform the SFP socket that the network device is now up, so that the
557  * module can be disabled by asserting TX_DISABLE, disabling the laser
558  * in optical modules. This should be called from the network device
559  * driver's &struct net_device_ops ndo_stop() method.
560  */
561 void sfp_upstream_stop(struct sfp_bus *bus)
562 {
563 	if (bus->registered)
564 		bus->socket_ops->stop(bus->sfp);
565 	bus->started = false;
566 }
567 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
568 
569 static void sfp_upstream_clear(struct sfp_bus *bus)
570 {
571 	bus->upstream_ops = NULL;
572 	bus->upstream = NULL;
573 }
574 
575 /**
576  * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
577  * @fwnode: firmware node for the parent device (MAC or PHY)
578  *
579  * Parse the parent device's firmware node for a SFP bus, and locate
580  * the sfp_bus structure, incrementing its reference count.  This must
581  * be put via sfp_bus_put() when done.
582  *
583  * Returns:
584  *	- on success, a pointer to the sfp_bus structure,
585  *	- %NULL if no SFP is specified,
586  *	- on failure, an error pointer value:
587  *
588  *	- corresponding to the errors detailed for
589  *	  fwnode_property_get_reference_args().
590  *	- %-ENOMEM if we failed to allocate the bus.
591  *	- an error from the upstream's connect_phy() method.
592  */
593 struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
594 {
595 	struct fwnode_reference_args ref;
596 	struct sfp_bus *bus;
597 	int ret;
598 
599 	ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
600 						 0, 0, &ref);
601 	if (ret == -ENOENT)
602 		return NULL;
603 	else if (ret < 0)
604 		return ERR_PTR(ret);
605 
606 	if (!fwnode_device_is_available(ref.fwnode)) {
607 		fwnode_handle_put(ref.fwnode);
608 		return NULL;
609 	}
610 
611 	bus = sfp_bus_get(ref.fwnode);
612 	fwnode_handle_put(ref.fwnode);
613 	if (!bus)
614 		return ERR_PTR(-ENOMEM);
615 
616 	return bus;
617 }
618 EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
619 
620 /**
621  * sfp_bus_add_upstream() - parse and register the neighbouring device
622  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
623  * @upstream: the upstream private data
624  * @ops: the upstream's &struct sfp_upstream_ops
625  *
626  * Add upstream driver for the SFP bus, and if the bus is complete, register
627  * the SFP bus using sfp_register_upstream().  This takes a reference on the
628  * bus, so it is safe to put the bus after this call.
629  *
630  * Returns:
631  *	- on success, a pointer to the sfp_bus structure,
632  *	- %NULL if no SFP is specified,
633  *	- on failure, an error pointer value:
634  *
635  *	- corresponding to the errors detailed for
636  *	  fwnode_property_get_reference_args().
637  *	- %-ENOMEM if we failed to allocate the bus.
638  *	- an error from the upstream's connect_phy() method.
639  */
640 int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
641 			 const struct sfp_upstream_ops *ops)
642 {
643 	int ret;
644 
645 	/* If no bus, return success */
646 	if (!bus)
647 		return 0;
648 
649 	rtnl_lock();
650 	kref_get(&bus->kref);
651 	bus->upstream_ops = ops;
652 	bus->upstream = upstream;
653 
654 	if (bus->sfp) {
655 		ret = sfp_register_bus(bus);
656 		if (ret)
657 			sfp_upstream_clear(bus);
658 	} else {
659 		ret = 0;
660 	}
661 	rtnl_unlock();
662 
663 	if (ret)
664 		sfp_bus_put(bus);
665 
666 	return ret;
667 }
668 EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
669 
670 /**
671  * sfp_bus_del_upstream() - Delete a sfp bus
672  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
673  *
674  * Delete a previously registered upstream connection for the SFP
675  * module. @bus should have been added by sfp_bus_add_upstream().
676  */
677 void sfp_bus_del_upstream(struct sfp_bus *bus)
678 {
679 	if (bus) {
680 		rtnl_lock();
681 		if (bus->sfp)
682 			sfp_unregister_bus(bus);
683 		sfp_upstream_clear(bus);
684 		rtnl_unlock();
685 
686 		sfp_bus_put(bus);
687 	}
688 }
689 EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
690 
691 /* Socket driver entry points */
692 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
693 {
694 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
695 	int ret = 0;
696 
697 	if (ops && ops->connect_phy)
698 		ret = ops->connect_phy(bus->upstream, phydev);
699 
700 	if (ret == 0)
701 		bus->phydev = phydev;
702 
703 	return ret;
704 }
705 EXPORT_SYMBOL_GPL(sfp_add_phy);
706 
707 void sfp_remove_phy(struct sfp_bus *bus)
708 {
709 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
710 
711 	if (ops && ops->disconnect_phy)
712 		ops->disconnect_phy(bus->upstream);
713 	bus->phydev = NULL;
714 }
715 EXPORT_SYMBOL_GPL(sfp_remove_phy);
716 
717 void sfp_link_up(struct sfp_bus *bus)
718 {
719 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
720 
721 	if (ops && ops->link_up)
722 		ops->link_up(bus->upstream);
723 }
724 EXPORT_SYMBOL_GPL(sfp_link_up);
725 
726 void sfp_link_down(struct sfp_bus *bus)
727 {
728 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
729 
730 	if (ops && ops->link_down)
731 		ops->link_down(bus->upstream);
732 }
733 EXPORT_SYMBOL_GPL(sfp_link_down);
734 
735 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
736 		      const struct sfp_quirk *quirk)
737 {
738 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
739 	int ret = 0;
740 
741 	bus->sfp_quirk = quirk;
742 
743 	if (ops && ops->module_insert)
744 		ret = ops->module_insert(bus->upstream, id);
745 
746 	return ret;
747 }
748 EXPORT_SYMBOL_GPL(sfp_module_insert);
749 
750 void sfp_module_remove(struct sfp_bus *bus)
751 {
752 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
753 
754 	if (ops && ops->module_remove)
755 		ops->module_remove(bus->upstream);
756 
757 	bus->sfp_quirk = NULL;
758 }
759 EXPORT_SYMBOL_GPL(sfp_module_remove);
760 
761 int sfp_module_start(struct sfp_bus *bus)
762 {
763 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
764 	int ret = 0;
765 
766 	if (ops && ops->module_start)
767 		ret = ops->module_start(bus->upstream);
768 
769 	return ret;
770 }
771 EXPORT_SYMBOL_GPL(sfp_module_start);
772 
773 void sfp_module_stop(struct sfp_bus *bus)
774 {
775 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
776 
777 	if (ops && ops->module_stop)
778 		ops->module_stop(bus->upstream);
779 }
780 EXPORT_SYMBOL_GPL(sfp_module_stop);
781 
782 static void sfp_socket_clear(struct sfp_bus *bus)
783 {
784 	bus->sfp_dev = NULL;
785 	bus->sfp = NULL;
786 	bus->socket_ops = NULL;
787 }
788 
789 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
790 				    const struct sfp_socket_ops *ops)
791 {
792 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
793 	int ret = 0;
794 
795 	if (bus) {
796 		rtnl_lock();
797 		bus->sfp_dev = dev;
798 		bus->sfp = sfp;
799 		bus->socket_ops = ops;
800 
801 		if (bus->upstream_ops) {
802 			ret = sfp_register_bus(bus);
803 			if (ret)
804 				sfp_socket_clear(bus);
805 		}
806 		rtnl_unlock();
807 	}
808 
809 	if (ret) {
810 		sfp_bus_put(bus);
811 		bus = NULL;
812 	}
813 
814 	return bus;
815 }
816 EXPORT_SYMBOL_GPL(sfp_register_socket);
817 
818 void sfp_unregister_socket(struct sfp_bus *bus)
819 {
820 	rtnl_lock();
821 	if (bus->upstream_ops)
822 		sfp_unregister_bus(bus);
823 	sfp_socket_clear(bus);
824 	rtnl_unlock();
825 
826 	sfp_bus_put(bus);
827 }
828 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
829