xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision c4a05cf0)
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 	const 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 	phylink_set(modes, Autoneg);
155 	phylink_set(modes, Pause);
156 	phylink_set(modes, Asym_Pause);
157 
158 	/* Decode the bitrate information to MBd */
159 	br_min = br_nom = br_max = 0;
160 	if (id->base.br_nominal) {
161 		if (id->base.br_nominal != 255) {
162 			br_nom = id->base.br_nominal * 100;
163 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
164 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
165 		} else if (id->ext.br_max) {
166 			br_nom = 250 * id->ext.br_max;
167 			br_max = br_nom + br_nom * id->ext.br_min / 100;
168 			br_min = br_nom - br_nom * id->ext.br_min / 100;
169 		}
170 
171 		/* When using passive cables, in case neither BR,min nor BR,max
172 		 * are specified, set br_min to 0 as the nominal value is then
173 		 * used as the maximum.
174 		 */
175 		if (br_min == br_max && id->base.sfp_ct_passive)
176 			br_min = 0;
177 	}
178 
179 	/* Set ethtool support from the compliance fields. */
180 	if (id->base.e10g_base_sr) {
181 		phylink_set(modes, 10000baseSR_Full);
182 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
183 	}
184 	if (id->base.e10g_base_lr) {
185 		phylink_set(modes, 10000baseLR_Full);
186 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
187 	}
188 	if (id->base.e10g_base_lrm) {
189 		phylink_set(modes, 10000baseLRM_Full);
190 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
191 	}
192 	if (id->base.e10g_base_er) {
193 		phylink_set(modes, 10000baseER_Full);
194 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
195 	}
196 	if (id->base.e1000_base_sx ||
197 	    id->base.e1000_base_lx ||
198 	    id->base.e1000_base_cx) {
199 		phylink_set(modes, 1000baseX_Full);
200 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
201 	}
202 	if (id->base.e1000_base_t) {
203 		phylink_set(modes, 1000baseT_Half);
204 		phylink_set(modes, 1000baseT_Full);
205 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
206 		__set_bit(PHY_INTERFACE_MODE_SGMII, interfaces);
207 	}
208 
209 	/* 1000Base-PX or 1000Base-BX10 */
210 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
211 	    br_min <= 1300 && br_max >= 1200) {
212 		phylink_set(modes, 1000baseX_Full);
213 		__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
214 	}
215 
216 	/* 100Base-FX, 100Base-LX, 100Base-PX, 100Base-BX10 */
217 	if (id->base.e100_base_fx || id->base.e100_base_lx) {
218 		phylink_set(modes, 100baseFX_Full);
219 		__set_bit(PHY_INTERFACE_MODE_100BASEX, interfaces);
220 	}
221 	if ((id->base.e_base_px || id->base.e_base_bx10) && br_nom == 100) {
222 		phylink_set(modes, 100baseFX_Full);
223 		__set_bit(PHY_INTERFACE_MODE_100BASEX, interfaces);
224 	}
225 
226 	/* For active or passive cables, select the link modes
227 	 * based on the bit rates and the cable compliance bytes.
228 	 */
229 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
230 		/* This may look odd, but some manufacturers use 12000MBd */
231 		if (br_min <= 12000 && br_max >= 10300) {
232 			phylink_set(modes, 10000baseCR_Full);
233 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
234 		}
235 		if (br_min <= 3200 && br_max >= 3100) {
236 			phylink_set(modes, 2500baseX_Full);
237 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
238 		}
239 		if (br_min <= 1300 && br_max >= 1200) {
240 			phylink_set(modes, 1000baseX_Full);
241 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
242 		}
243 	}
244 	if (id->base.sfp_ct_passive) {
245 		if (id->base.passive.sff8431_app_e) {
246 			phylink_set(modes, 10000baseCR_Full);
247 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
248 		}
249 	}
250 	if (id->base.sfp_ct_active) {
251 		if (id->base.active.sff8431_app_e ||
252 		    id->base.active.sff8431_lim) {
253 			phylink_set(modes, 10000baseCR_Full);
254 			__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
255 		}
256 	}
257 
258 	switch (id->base.extended_cc) {
259 	case SFF8024_ECC_UNSPEC:
260 		break;
261 	case SFF8024_ECC_100G_25GAUI_C2M_AOC:
262 		if (br_min <= 28000 && br_max >= 25000) {
263 			/* 25GBASE-R, possibly with FEC */
264 			__set_bit(PHY_INTERFACE_MODE_25GBASER, interfaces);
265 			/* There is currently no link mode for 25000base
266 			 * with unspecified range, reuse SR.
267 			 */
268 			phylink_set(modes, 25000baseSR_Full);
269 		}
270 		break;
271 	case SFF8024_ECC_100GBASE_SR4_25GBASE_SR:
272 		phylink_set(modes, 100000baseSR4_Full);
273 		phylink_set(modes, 25000baseSR_Full);
274 		__set_bit(PHY_INTERFACE_MODE_25GBASER, interfaces);
275 		break;
276 	case SFF8024_ECC_100GBASE_LR4_25GBASE_LR:
277 	case SFF8024_ECC_100GBASE_ER4_25GBASE_ER:
278 		phylink_set(modes, 100000baseLR4_ER4_Full);
279 		break;
280 	case SFF8024_ECC_100GBASE_CR4:
281 		phylink_set(modes, 100000baseCR4_Full);
282 		fallthrough;
283 	case SFF8024_ECC_25GBASE_CR_S:
284 	case SFF8024_ECC_25GBASE_CR_N:
285 		phylink_set(modes, 25000baseCR_Full);
286 		__set_bit(PHY_INTERFACE_MODE_25GBASER, interfaces);
287 		break;
288 	case SFF8024_ECC_10GBASE_T_SFI:
289 	case SFF8024_ECC_10GBASE_T_SR:
290 		phylink_set(modes, 10000baseT_Full);
291 		__set_bit(PHY_INTERFACE_MODE_10GBASER, interfaces);
292 		break;
293 	case SFF8024_ECC_5GBASE_T:
294 		phylink_set(modes, 5000baseT_Full);
295 		__set_bit(PHY_INTERFACE_MODE_5GBASER, interfaces);
296 		break;
297 	case SFF8024_ECC_2_5GBASE_T:
298 		phylink_set(modes, 2500baseT_Full);
299 		__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
300 		break;
301 	default:
302 		dev_warn(bus->sfp_dev,
303 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
304 			 id->base.extended_cc);
305 		break;
306 	}
307 
308 	/* For fibre channel SFP, derive possible BaseX modes */
309 	if (id->base.fc_speed_100 ||
310 	    id->base.fc_speed_200 ||
311 	    id->base.fc_speed_400) {
312 		if (id->base.br_nominal >= 31) {
313 			phylink_set(modes, 2500baseX_Full);
314 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
315 		}
316 		if (id->base.br_nominal >= 12) {
317 			phylink_set(modes, 1000baseX_Full);
318 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
319 		}
320 	}
321 
322 	/* If we haven't discovered any modes that this module supports, try
323 	 * the bitrate to determine supported modes. Some BiDi modules (eg,
324 	 * 1310nm/1550nm) are not 1000BASE-BX compliant due to the differing
325 	 * wavelengths, so do not set any transceiver bits.
326 	 *
327 	 * Do the same for modules supporting 2500BASE-X. Note that some
328 	 * modules use 2500Mbaud rather than 3100 or 3200Mbaud for
329 	 * 2500BASE-X, so we allow some slack here.
330 	 */
331 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS) && br_nom) {
332 		if (br_min <= 1300 && br_max >= 1200) {
333 			phylink_set(modes, 1000baseX_Full);
334 			__set_bit(PHY_INTERFACE_MODE_1000BASEX, interfaces);
335 		}
336 		if (br_min <= 3200 && br_max >= 2500) {
337 			phylink_set(modes, 2500baseX_Full);
338 			__set_bit(PHY_INTERFACE_MODE_2500BASEX, interfaces);
339 		}
340 	}
341 
342 	if (bus->sfp_quirk && bus->sfp_quirk->modes)
343 		bus->sfp_quirk->modes(id, modes, interfaces);
344 
345 	linkmode_or(support, support, modes);
346 }
347 EXPORT_SYMBOL_GPL(sfp_parse_support);
348 
349 /**
350  * sfp_select_interface() - Select appropriate phy_interface_t mode
351  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
352  * @link_modes: ethtool link modes mask
353  *
354  * Derive the phy_interface_t mode for the SFP module from the link
355  * modes mask.
356  */
357 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
358 				     unsigned long *link_modes)
359 {
360 	if (phylink_test(link_modes, 25000baseCR_Full) ||
361 	    phylink_test(link_modes, 25000baseKR_Full) ||
362 	    phylink_test(link_modes, 25000baseSR_Full))
363 		return PHY_INTERFACE_MODE_25GBASER;
364 
365 	if (phylink_test(link_modes, 10000baseCR_Full) ||
366 	    phylink_test(link_modes, 10000baseSR_Full) ||
367 	    phylink_test(link_modes, 10000baseLR_Full) ||
368 	    phylink_test(link_modes, 10000baseLRM_Full) ||
369 	    phylink_test(link_modes, 10000baseER_Full) ||
370 	    phylink_test(link_modes, 10000baseT_Full))
371 		return PHY_INTERFACE_MODE_10GBASER;
372 
373 	if (phylink_test(link_modes, 5000baseT_Full))
374 		return PHY_INTERFACE_MODE_5GBASER;
375 
376 	if (phylink_test(link_modes, 2500baseX_Full))
377 		return PHY_INTERFACE_MODE_2500BASEX;
378 
379 	if (phylink_test(link_modes, 1000baseT_Half) ||
380 	    phylink_test(link_modes, 1000baseT_Full))
381 		return PHY_INTERFACE_MODE_SGMII;
382 
383 	if (phylink_test(link_modes, 1000baseX_Full))
384 		return PHY_INTERFACE_MODE_1000BASEX;
385 
386 	if (phylink_test(link_modes, 100baseFX_Full))
387 		return PHY_INTERFACE_MODE_100BASEX;
388 
389 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
390 
391 	return PHY_INTERFACE_MODE_NA;
392 }
393 EXPORT_SYMBOL_GPL(sfp_select_interface);
394 
395 static LIST_HEAD(sfp_buses);
396 static DEFINE_MUTEX(sfp_mutex);
397 
398 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
399 {
400 	return bus->registered ? bus->upstream_ops : NULL;
401 }
402 
403 static struct sfp_bus *sfp_bus_get(const struct fwnode_handle *fwnode)
404 {
405 	struct sfp_bus *sfp, *new, *found = NULL;
406 
407 	new = kzalloc(sizeof(*new), GFP_KERNEL);
408 
409 	mutex_lock(&sfp_mutex);
410 
411 	list_for_each_entry(sfp, &sfp_buses, node) {
412 		if (sfp->fwnode == fwnode) {
413 			kref_get(&sfp->kref);
414 			found = sfp;
415 			break;
416 		}
417 	}
418 
419 	if (!found && new) {
420 		kref_init(&new->kref);
421 		new->fwnode = fwnode;
422 		list_add(&new->node, &sfp_buses);
423 		found = new;
424 		new = NULL;
425 	}
426 
427 	mutex_unlock(&sfp_mutex);
428 
429 	kfree(new);
430 
431 	return found;
432 }
433 
434 static void sfp_bus_release(struct kref *kref)
435 {
436 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
437 
438 	list_del(&bus->node);
439 	mutex_unlock(&sfp_mutex);
440 	kfree(bus);
441 }
442 
443 /**
444  * sfp_bus_put() - put a reference on the &struct sfp_bus
445  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
446  *
447  * Put a reference on the &struct sfp_bus and free the underlying structure
448  * if this was the last reference.
449  */
450 void sfp_bus_put(struct sfp_bus *bus)
451 {
452 	if (bus)
453 		kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
454 }
455 EXPORT_SYMBOL_GPL(sfp_bus_put);
456 
457 static int sfp_register_bus(struct sfp_bus *bus)
458 {
459 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
460 	int ret;
461 
462 	if (ops) {
463 		if (ops->link_down)
464 			ops->link_down(bus->upstream);
465 		if (ops->connect_phy && bus->phydev) {
466 			ret = ops->connect_phy(bus->upstream, bus->phydev);
467 			if (ret)
468 				return ret;
469 		}
470 	}
471 	bus->registered = true;
472 	bus->socket_ops->attach(bus->sfp);
473 	if (bus->started)
474 		bus->socket_ops->start(bus->sfp);
475 	bus->upstream_ops->attach(bus->upstream, bus);
476 	return 0;
477 }
478 
479 static void sfp_unregister_bus(struct sfp_bus *bus)
480 {
481 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
482 
483 	if (bus->registered) {
484 		bus->upstream_ops->detach(bus->upstream, bus);
485 		if (bus->started)
486 			bus->socket_ops->stop(bus->sfp);
487 		bus->socket_ops->detach(bus->sfp);
488 		if (bus->phydev && ops && ops->disconnect_phy)
489 			ops->disconnect_phy(bus->upstream);
490 	}
491 	bus->registered = false;
492 }
493 
494 /**
495  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
496  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
497  * @modinfo: a &struct ethtool_modinfo
498  *
499  * Fill in the type and eeprom_len parameters in @modinfo for a module on
500  * the sfp bus specified by @bus.
501  *
502  * Returns 0 on success or a negative errno number.
503  */
504 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
505 {
506 	return bus->socket_ops->module_info(bus->sfp, modinfo);
507 }
508 EXPORT_SYMBOL_GPL(sfp_get_module_info);
509 
510 /**
511  * sfp_get_module_eeprom() - Read the SFP module EEPROM
512  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
513  * @ee: a &struct ethtool_eeprom
514  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
515  *
516  * Read the EEPROM as specified by the supplied @ee. See the documentation
517  * for &struct ethtool_eeprom for the region to be read.
518  *
519  * Returns 0 on success or a negative errno number.
520  */
521 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
522 			  u8 *data)
523 {
524 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
525 }
526 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
527 
528 /**
529  * sfp_get_module_eeprom_by_page() - Read a page from the SFP module EEPROM
530  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
531  * @page: a &struct ethtool_module_eeprom
532  * @extack: extack for reporting problems
533  *
534  * Read an EEPROM page as specified by the supplied @page. See the
535  * documentation for &struct ethtool_module_eeprom for the page to be read.
536  *
537  * Returns 0 on success or a negative errno number. More error
538  * information might be provided via extack
539  */
540 int sfp_get_module_eeprom_by_page(struct sfp_bus *bus,
541 				  const struct ethtool_module_eeprom *page,
542 				  struct netlink_ext_ack *extack)
543 {
544 	return bus->socket_ops->module_eeprom_by_page(bus->sfp, page, extack);
545 }
546 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom_by_page);
547 
548 /**
549  * sfp_upstream_start() - Inform the SFP that the network device is up
550  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
551  *
552  * Inform the SFP socket that the network device is now up, so that the
553  * module can be enabled by allowing TX_DISABLE to be deasserted. This
554  * should be called from the network device driver's &struct net_device_ops
555  * ndo_open() method.
556  */
557 void sfp_upstream_start(struct sfp_bus *bus)
558 {
559 	if (bus->registered)
560 		bus->socket_ops->start(bus->sfp);
561 	bus->started = true;
562 }
563 EXPORT_SYMBOL_GPL(sfp_upstream_start);
564 
565 /**
566  * sfp_upstream_stop() - Inform the SFP that the network device is down
567  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
568  *
569  * Inform the SFP socket that the network device is now up, so that the
570  * module can be disabled by asserting TX_DISABLE, disabling the laser
571  * in optical modules. This should be called from the network device
572  * driver's &struct net_device_ops ndo_stop() method.
573  */
574 void sfp_upstream_stop(struct sfp_bus *bus)
575 {
576 	if (bus->registered)
577 		bus->socket_ops->stop(bus->sfp);
578 	bus->started = false;
579 }
580 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
581 
582 static void sfp_upstream_clear(struct sfp_bus *bus)
583 {
584 	bus->upstream_ops = NULL;
585 	bus->upstream = NULL;
586 }
587 
588 /**
589  * sfp_upstream_set_signal_rate() - set data signalling rate
590  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
591  * @rate_kbd: signalling rate in units of 1000 baud
592  *
593  * Configure the rate select settings on the SFP module for the signalling
594  * rate (not the same as the data rate).
595  *
596  * Locks that may be held:
597  *  Phylink's state_mutex
598  *  rtnl lock
599  *  SFP's sm_mutex
600  */
601 void sfp_upstream_set_signal_rate(struct sfp_bus *bus, unsigned int rate_kbd)
602 {
603 	if (bus->registered)
604 		bus->socket_ops->set_signal_rate(bus->sfp, rate_kbd);
605 }
606 EXPORT_SYMBOL_GPL(sfp_upstream_set_signal_rate);
607 
608 /**
609  * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
610  * @fwnode: firmware node for the parent device (MAC or PHY)
611  *
612  * Parse the parent device's firmware node for a SFP bus, and locate
613  * the sfp_bus structure, incrementing its reference count.  This must
614  * be put via sfp_bus_put() when done.
615  *
616  * Returns:
617  *	- on success, a pointer to the sfp_bus structure,
618  *	- %NULL if no SFP is specified,
619  *	- on failure, an error pointer value:
620  *
621  *	- corresponding to the errors detailed for
622  *	  fwnode_property_get_reference_args().
623  *	- %-ENOMEM if we failed to allocate the bus.
624  *	- an error from the upstream's connect_phy() method.
625  */
626 struct sfp_bus *sfp_bus_find_fwnode(const struct fwnode_handle *fwnode)
627 {
628 	struct fwnode_reference_args ref;
629 	struct sfp_bus *bus;
630 	int ret;
631 
632 	ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
633 						 0, 0, &ref);
634 	if (ret == -ENOENT)
635 		return NULL;
636 	else if (ret < 0)
637 		return ERR_PTR(ret);
638 
639 	if (!fwnode_device_is_available(ref.fwnode)) {
640 		fwnode_handle_put(ref.fwnode);
641 		return NULL;
642 	}
643 
644 	bus = sfp_bus_get(ref.fwnode);
645 	fwnode_handle_put(ref.fwnode);
646 	if (!bus)
647 		return ERR_PTR(-ENOMEM);
648 
649 	return bus;
650 }
651 EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
652 
653 /**
654  * sfp_bus_add_upstream() - parse and register the neighbouring device
655  * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
656  * @upstream: the upstream private data
657  * @ops: the upstream's &struct sfp_upstream_ops
658  *
659  * Add upstream driver for the SFP bus, and if the bus is complete, register
660  * the SFP bus using sfp_register_upstream().  This takes a reference on the
661  * bus, so it is safe to put the bus after this call.
662  *
663  * Returns:
664  *	- on success, a pointer to the sfp_bus structure,
665  *	- %NULL if no SFP is specified,
666  *	- on failure, an error pointer value:
667  *
668  *	- corresponding to the errors detailed for
669  *	  fwnode_property_get_reference_args().
670  *	- %-ENOMEM if we failed to allocate the bus.
671  *	- an error from the upstream's connect_phy() method.
672  */
673 int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
674 			 const struct sfp_upstream_ops *ops)
675 {
676 	int ret;
677 
678 	/* If no bus, return success */
679 	if (!bus)
680 		return 0;
681 
682 	rtnl_lock();
683 	kref_get(&bus->kref);
684 	bus->upstream_ops = ops;
685 	bus->upstream = upstream;
686 
687 	if (bus->sfp) {
688 		ret = sfp_register_bus(bus);
689 		if (ret)
690 			sfp_upstream_clear(bus);
691 	} else {
692 		ret = 0;
693 	}
694 	rtnl_unlock();
695 
696 	if (ret)
697 		sfp_bus_put(bus);
698 
699 	return ret;
700 }
701 EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
702 
703 /**
704  * sfp_bus_del_upstream() - Delete a sfp bus
705  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
706  *
707  * Delete a previously registered upstream connection for the SFP
708  * module. @bus should have been added by sfp_bus_add_upstream().
709  */
710 void sfp_bus_del_upstream(struct sfp_bus *bus)
711 {
712 	if (bus) {
713 		rtnl_lock();
714 		if (bus->sfp)
715 			sfp_unregister_bus(bus);
716 		sfp_upstream_clear(bus);
717 		rtnl_unlock();
718 
719 		sfp_bus_put(bus);
720 	}
721 }
722 EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
723 
724 /* Socket driver entry points */
725 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
726 {
727 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
728 	int ret = 0;
729 
730 	if (ops && ops->connect_phy)
731 		ret = ops->connect_phy(bus->upstream, phydev);
732 
733 	if (ret == 0)
734 		bus->phydev = phydev;
735 
736 	return ret;
737 }
738 EXPORT_SYMBOL_GPL(sfp_add_phy);
739 
740 void sfp_remove_phy(struct sfp_bus *bus)
741 {
742 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
743 
744 	if (ops && ops->disconnect_phy)
745 		ops->disconnect_phy(bus->upstream);
746 	bus->phydev = NULL;
747 }
748 EXPORT_SYMBOL_GPL(sfp_remove_phy);
749 
750 void sfp_link_up(struct sfp_bus *bus)
751 {
752 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
753 
754 	if (ops && ops->link_up)
755 		ops->link_up(bus->upstream);
756 }
757 EXPORT_SYMBOL_GPL(sfp_link_up);
758 
759 void sfp_link_down(struct sfp_bus *bus)
760 {
761 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
762 
763 	if (ops && ops->link_down)
764 		ops->link_down(bus->upstream);
765 }
766 EXPORT_SYMBOL_GPL(sfp_link_down);
767 
768 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
769 		      const struct sfp_quirk *quirk)
770 {
771 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
772 	int ret = 0;
773 
774 	bus->sfp_quirk = quirk;
775 
776 	if (ops && ops->module_insert)
777 		ret = ops->module_insert(bus->upstream, id);
778 
779 	return ret;
780 }
781 EXPORT_SYMBOL_GPL(sfp_module_insert);
782 
783 void sfp_module_remove(struct sfp_bus *bus)
784 {
785 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
786 
787 	if (ops && ops->module_remove)
788 		ops->module_remove(bus->upstream);
789 
790 	bus->sfp_quirk = NULL;
791 }
792 EXPORT_SYMBOL_GPL(sfp_module_remove);
793 
794 int sfp_module_start(struct sfp_bus *bus)
795 {
796 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
797 	int ret = 0;
798 
799 	if (ops && ops->module_start)
800 		ret = ops->module_start(bus->upstream);
801 
802 	return ret;
803 }
804 EXPORT_SYMBOL_GPL(sfp_module_start);
805 
806 void sfp_module_stop(struct sfp_bus *bus)
807 {
808 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
809 
810 	if (ops && ops->module_stop)
811 		ops->module_stop(bus->upstream);
812 }
813 EXPORT_SYMBOL_GPL(sfp_module_stop);
814 
815 static void sfp_socket_clear(struct sfp_bus *bus)
816 {
817 	bus->sfp_dev = NULL;
818 	bus->sfp = NULL;
819 	bus->socket_ops = NULL;
820 }
821 
822 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
823 				    const struct sfp_socket_ops *ops)
824 {
825 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
826 	int ret = 0;
827 
828 	if (bus) {
829 		rtnl_lock();
830 		bus->sfp_dev = dev;
831 		bus->sfp = sfp;
832 		bus->socket_ops = ops;
833 
834 		if (bus->upstream_ops) {
835 			ret = sfp_register_bus(bus);
836 			if (ret)
837 				sfp_socket_clear(bus);
838 		}
839 		rtnl_unlock();
840 	}
841 
842 	if (ret) {
843 		sfp_bus_put(bus);
844 		bus = NULL;
845 	}
846 
847 	return bus;
848 }
849 EXPORT_SYMBOL_GPL(sfp_register_socket);
850 
851 void sfp_unregister_socket(struct sfp_bus *bus)
852 {
853 	rtnl_lock();
854 	if (bus->upstream_ops)
855 		sfp_unregister_bus(bus);
856 	sfp_socket_clear(bus);
857 	rtnl_unlock();
858 
859 	sfp_bus_put(bus);
860 }
861 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
862