xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision 4fc4dca8) 
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/rtnetlink.h>
8 #include <linux/slab.h>
9 
10 #include "sfp.h"
11 
12 /**
13  * struct sfp_bus - internal representation of a sfp bus
14  */
15 struct sfp_bus {
16 	/* private: */
17 	struct kref kref;
18 	struct list_head node;
19 	struct fwnode_handle *fwnode;
20 
21 	const struct sfp_socket_ops *socket_ops;
22 	struct device *sfp_dev;
23 	struct sfp *sfp;
24 
25 	const struct sfp_upstream_ops *upstream_ops;
26 	void *upstream;
27 	struct net_device *netdev;
28 	struct phy_device *phydev;
29 
30 	bool registered;
31 	bool started;
32 };
33 
34 /**
35  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
36  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
37  * @id: a pointer to the module's &struct sfp_eeprom_id
38  * @support: optional pointer to an array of unsigned long for the
39  *   ethtool support mask
40  *
41  * Parse the EEPROM identification given in @id, and return one of
42  * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
43  * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
44  * the connector type.
45  *
46  * If the port type is not known, returns %PORT_OTHER.
47  */
48 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
49 		   unsigned long *support)
50 {
51 	int port;
52 
53 	/* port is the physical connector, set this from the connector field. */
54 	switch (id->base.connector) {
55 	case SFP_CONNECTOR_SC:
56 	case SFP_CONNECTOR_FIBERJACK:
57 	case SFP_CONNECTOR_LC:
58 	case SFP_CONNECTOR_MT_RJ:
59 	case SFP_CONNECTOR_MU:
60 	case SFP_CONNECTOR_OPTICAL_PIGTAIL:
61 		port = PORT_FIBRE;
62 		break;
63 
64 	case SFP_CONNECTOR_RJ45:
65 		port = PORT_TP;
66 		break;
67 
68 	case SFP_CONNECTOR_COPPER_PIGTAIL:
69 		port = PORT_DA;
70 		break;
71 
72 	case SFP_CONNECTOR_UNSPEC:
73 		if (id->base.e1000_base_t) {
74 			port = PORT_TP;
75 			break;
76 		}
77 		/* fallthrough */
78 	case SFP_CONNECTOR_SG: /* guess */
79 	case SFP_CONNECTOR_MPO_1X12:
80 	case SFP_CONNECTOR_MPO_2X16:
81 	case SFP_CONNECTOR_HSSDC_II:
82 	case SFP_CONNECTOR_NOSEPARATE:
83 	case SFP_CONNECTOR_MXC_2X16:
84 		port = PORT_OTHER;
85 		break;
86 	default:
87 		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
88 			 id->base.connector);
89 		port = PORT_OTHER;
90 		break;
91 	}
92 
93 	if (support) {
94 		switch (port) {
95 		case PORT_FIBRE:
96 			phylink_set(support, FIBRE);
97 			break;
98 
99 		case PORT_TP:
100 			phylink_set(support, TP);
101 			break;
102 		}
103 	}
104 
105 	return port;
106 }
107 EXPORT_SYMBOL_GPL(sfp_parse_port);
108 
109 /**
110  * sfp_parse_support() - Parse the eeprom id for supported link modes
111  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
112  * @id: a pointer to the module's &struct sfp_eeprom_id
113  * @support: pointer to an array of unsigned long for the ethtool support mask
114  *
115  * Parse the EEPROM identification information and derive the supported
116  * ethtool link modes for the module.
117  */
118 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
119 		       unsigned long *support)
120 {
121 	unsigned int br_min, br_nom, br_max;
122 	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
123 
124 	/* Decode the bitrate information to MBd */
125 	br_min = br_nom = br_max = 0;
126 	if (id->base.br_nominal) {
127 		if (id->base.br_nominal != 255) {
128 			br_nom = id->base.br_nominal * 100;
129 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
130 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
131 		} else if (id->ext.br_max) {
132 			br_nom = 250 * id->ext.br_max;
133 			br_max = br_nom + br_nom * id->ext.br_min / 100;
134 			br_min = br_nom - br_nom * id->ext.br_min / 100;
135 		}
136 
137 		/* When using passive cables, in case neither BR,min nor BR,max
138 		 * are specified, set br_min to 0 as the nominal value is then
139 		 * used as the maximum.
140 		 */
141 		if (br_min == br_max && id->base.sfp_ct_passive)
142 			br_min = 0;
143 	}
144 
145 	/* Set ethtool support from the compliance fields. */
146 	if (id->base.e10g_base_sr)
147 		phylink_set(modes, 10000baseSR_Full);
148 	if (id->base.e10g_base_lr)
149 		phylink_set(modes, 10000baseLR_Full);
150 	if (id->base.e10g_base_lrm)
151 		phylink_set(modes, 10000baseLRM_Full);
152 	if (id->base.e10g_base_er)
153 		phylink_set(modes, 10000baseER_Full);
154 	if (id->base.e1000_base_sx ||
155 	    id->base.e1000_base_lx ||
156 	    id->base.e1000_base_cx)
157 		phylink_set(modes, 1000baseX_Full);
158 	if (id->base.e1000_base_t) {
159 		phylink_set(modes, 1000baseT_Half);
160 		phylink_set(modes, 1000baseT_Full);
161 	}
162 
163 	/* 1000Base-PX or 1000Base-BX10 */
164 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
165 	    br_min <= 1300 && br_max >= 1200)
166 		phylink_set(modes, 1000baseX_Full);
167 
168 	/* For active or passive cables, select the link modes
169 	 * based on the bit rates and the cable compliance bytes.
170 	 */
171 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
172 		/* This may look odd, but some manufacturers use 12000MBd */
173 		if (br_min <= 12000 && br_max >= 10300)
174 			phylink_set(modes, 10000baseCR_Full);
175 		if (br_min <= 3200 && br_max >= 3100)
176 			phylink_set(modes, 2500baseX_Full);
177 		if (br_min <= 1300 && br_max >= 1200)
178 			phylink_set(modes, 1000baseX_Full);
179 	}
180 	if (id->base.sfp_ct_passive) {
181 		if (id->base.passive.sff8431_app_e)
182 			phylink_set(modes, 10000baseCR_Full);
183 	}
184 	if (id->base.sfp_ct_active) {
185 		if (id->base.active.sff8431_app_e ||
186 		    id->base.active.sff8431_lim) {
187 			phylink_set(modes, 10000baseCR_Full);
188 		}
189 	}
190 
191 	switch (id->base.extended_cc) {
192 	case 0x00: /* Unspecified */
193 		break;
194 	case 0x02: /* 100Gbase-SR4 or 25Gbase-SR */
195 		phylink_set(modes, 100000baseSR4_Full);
196 		phylink_set(modes, 25000baseSR_Full);
197 		break;
198 	case 0x03: /* 100Gbase-LR4 or 25Gbase-LR */
199 	case 0x04: /* 100Gbase-ER4 or 25Gbase-ER */
200 		phylink_set(modes, 100000baseLR4_ER4_Full);
201 		break;
202 	case 0x0b: /* 100Gbase-CR4 or 25Gbase-CR CA-L */
203 	case 0x0c: /* 25Gbase-CR CA-S */
204 	case 0x0d: /* 25Gbase-CR CA-N */
205 		phylink_set(modes, 100000baseCR4_Full);
206 		phylink_set(modes, 25000baseCR_Full);
207 		break;
208 	default:
209 		dev_warn(bus->sfp_dev,
210 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
211 			 id->base.extended_cc);
212 		break;
213 	}
214 
215 	/* For fibre channel SFP, derive possible BaseX modes */
216 	if (id->base.fc_speed_100 ||
217 	    id->base.fc_speed_200 ||
218 	    id->base.fc_speed_400) {
219 		if (id->base.br_nominal >= 31)
220 			phylink_set(modes, 2500baseX_Full);
221 		if (id->base.br_nominal >= 12)
222 			phylink_set(modes, 1000baseX_Full);
223 	}
224 
225 	/* If we haven't discovered any modes that this module supports, try
226 	 * the encoding and bitrate to determine supported modes. Some BiDi
227 	 * modules (eg, 1310nm/1550nm) are not 1000BASE-BX compliant due to
228 	 * the differing wavelengths, so do not set any transceiver bits.
229 	 */
230 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS)) {
231 		/* If the encoding and bit rate allows 1000baseX */
232 		if (id->base.encoding == SFP_ENCODING_8B10B && br_nom &&
233 		    br_min <= 1300 && br_max >= 1200)
234 			phylink_set(modes, 1000baseX_Full);
235 	}
236 
237 	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
238 
239 	phylink_set(support, Autoneg);
240 	phylink_set(support, Pause);
241 	phylink_set(support, Asym_Pause);
242 }
243 EXPORT_SYMBOL_GPL(sfp_parse_support);
244 
245 /**
246  * sfp_select_interface() - Select appropriate phy_interface_t mode
247  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
248  * @id: a pointer to the module's &struct sfp_eeprom_id
249  * @link_modes: ethtool link modes mask
250  *
251  * Derive the phy_interface_t mode for the information found in the
252  * module's identifying EEPROM and the link modes mask. There is no
253  * standard or defined way to derive this information, so we decide
254  * based upon the link mode mask.
255  */
256 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
257 				     const struct sfp_eeprom_id *id,
258 				     unsigned long *link_modes)
259 {
260 	if (phylink_test(link_modes, 10000baseCR_Full) ||
261 	    phylink_test(link_modes, 10000baseSR_Full) ||
262 	    phylink_test(link_modes, 10000baseLR_Full) ||
263 	    phylink_test(link_modes, 10000baseLRM_Full) ||
264 	    phylink_test(link_modes, 10000baseER_Full))
265 		return PHY_INTERFACE_MODE_10GKR;
266 
267 	if (phylink_test(link_modes, 2500baseX_Full))
268 		return PHY_INTERFACE_MODE_2500BASEX;
269 
270 	if (id->base.e1000_base_t ||
271 	    id->base.e100_base_lx ||
272 	    id->base.e100_base_fx)
273 		return PHY_INTERFACE_MODE_SGMII;
274 
275 	if (phylink_test(link_modes, 1000baseX_Full))
276 		return PHY_INTERFACE_MODE_1000BASEX;
277 
278 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
279 
280 	return PHY_INTERFACE_MODE_NA;
281 }
282 EXPORT_SYMBOL_GPL(sfp_select_interface);
283 
284 static LIST_HEAD(sfp_buses);
285 static DEFINE_MUTEX(sfp_mutex);
286 
287 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
288 {
289 	return bus->registered ? bus->upstream_ops : NULL;
290 }
291 
292 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
293 {
294 	struct sfp_bus *sfp, *new, *found = NULL;
295 
296 	new = kzalloc(sizeof(*new), GFP_KERNEL);
297 
298 	mutex_lock(&sfp_mutex);
299 
300 	list_for_each_entry(sfp, &sfp_buses, node) {
301 		if (sfp->fwnode == fwnode) {
302 			kref_get(&sfp->kref);
303 			found = sfp;
304 			break;
305 		}
306 	}
307 
308 	if (!found && new) {
309 		kref_init(&new->kref);
310 		new->fwnode = fwnode;
311 		list_add(&new->node, &sfp_buses);
312 		found = new;
313 		new = NULL;
314 	}
315 
316 	mutex_unlock(&sfp_mutex);
317 
318 	kfree(new);
319 
320 	return found;
321 }
322 
323 static void sfp_bus_release(struct kref *kref)
324 {
325 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
326 
327 	list_del(&bus->node);
328 	mutex_unlock(&sfp_mutex);
329 	kfree(bus);
330 }
331 
332 static void sfp_bus_put(struct sfp_bus *bus)
333 {
334 	kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
335 }
336 
337 static int sfp_register_bus(struct sfp_bus *bus)
338 {
339 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
340 	int ret;
341 
342 	if (ops) {
343 		if (ops->link_down)
344 			ops->link_down(bus->upstream);
345 		if (ops->connect_phy && bus->phydev) {
346 			ret = ops->connect_phy(bus->upstream, bus->phydev);
347 			if (ret)
348 				return ret;
349 		}
350 	}
351 	bus->socket_ops->attach(bus->sfp);
352 	if (bus->started)
353 		bus->socket_ops->start(bus->sfp);
354 	bus->netdev->sfp_bus = bus;
355 	bus->registered = true;
356 	return 0;
357 }
358 
359 static void sfp_unregister_bus(struct sfp_bus *bus)
360 {
361 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
362 
363 	bus->netdev->sfp_bus = NULL;
364 	if (bus->registered) {
365 		if (bus->started)
366 			bus->socket_ops->stop(bus->sfp);
367 		bus->socket_ops->detach(bus->sfp);
368 		if (bus->phydev && ops && ops->disconnect_phy)
369 			ops->disconnect_phy(bus->upstream);
370 	}
371 	bus->registered = false;
372 }
373 
374 /**
375  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
376  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
377  * @modinfo: a &struct ethtool_modinfo
378  *
379  * Fill in the type and eeprom_len parameters in @modinfo for a module on
380  * the sfp bus specified by @bus.
381  *
382  * Returns 0 on success or a negative errno number.
383  */
384 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
385 {
386 	return bus->socket_ops->module_info(bus->sfp, modinfo);
387 }
388 EXPORT_SYMBOL_GPL(sfp_get_module_info);
389 
390 /**
391  * sfp_get_module_eeprom() - Read the SFP module EEPROM
392  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
393  * @ee: a &struct ethtool_eeprom
394  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
395  *
396  * Read the EEPROM as specified by the supplied @ee. See the documentation
397  * for &struct ethtool_eeprom for the region to be read.
398  *
399  * Returns 0 on success or a negative errno number.
400  */
401 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
402 			  u8 *data)
403 {
404 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
405 }
406 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
407 
408 /**
409  * sfp_upstream_start() - Inform the SFP that the network device is up
410  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
411  *
412  * Inform the SFP socket that the network device is now up, so that the
413  * module can be enabled by allowing TX_DISABLE to be deasserted. This
414  * should be called from the network device driver's &struct net_device_ops
415  * ndo_open() method.
416  */
417 void sfp_upstream_start(struct sfp_bus *bus)
418 {
419 	if (bus->registered)
420 		bus->socket_ops->start(bus->sfp);
421 	bus->started = true;
422 }
423 EXPORT_SYMBOL_GPL(sfp_upstream_start);
424 
425 /**
426  * sfp_upstream_stop() - Inform the SFP that the network device is down
427  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
428  *
429  * Inform the SFP socket that the network device is now up, so that the
430  * module can be disabled by asserting TX_DISABLE, disabling the laser
431  * in optical modules. This should be called from the network device
432  * driver's &struct net_device_ops ndo_stop() method.
433  */
434 void sfp_upstream_stop(struct sfp_bus *bus)
435 {
436 	if (bus->registered)
437 		bus->socket_ops->stop(bus->sfp);
438 	bus->started = false;
439 }
440 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
441 
442 static void sfp_upstream_clear(struct sfp_bus *bus)
443 {
444 	bus->upstream_ops = NULL;
445 	bus->upstream = NULL;
446 	bus->netdev = NULL;
447 }
448 
449 /**
450  * sfp_register_upstream() - Register the neighbouring device
451  * @fwnode: firmware node for the SFP bus
452  * @ndev: network device associated with the interface
453  * @upstream: the upstream private data
454  * @ops: the upstream's &struct sfp_upstream_ops
455  *
456  * Register the upstream device (eg, PHY) with the SFP bus. MAC drivers
457  * should use phylink, which will call this function for them. Returns
458  * a pointer to the allocated &struct sfp_bus.
459  *
460  * On error, returns %NULL.
461  */
462 struct sfp_bus *sfp_register_upstream(struct fwnode_handle *fwnode,
463 				      struct net_device *ndev, void *upstream,
464 				      const struct sfp_upstream_ops *ops)
465 {
466 	struct sfp_bus *bus = sfp_bus_get(fwnode);
467 	int ret = 0;
468 
469 	if (bus) {
470 		rtnl_lock();
471 		bus->upstream_ops = ops;
472 		bus->upstream = upstream;
473 		bus->netdev = ndev;
474 
475 		if (bus->sfp) {
476 			ret = sfp_register_bus(bus);
477 			if (ret)
478 				sfp_upstream_clear(bus);
479 		}
480 		rtnl_unlock();
481 	}
482 
483 	if (ret) {
484 		sfp_bus_put(bus);
485 		bus = NULL;
486 	}
487 
488 	return bus;
489 }
490 EXPORT_SYMBOL_GPL(sfp_register_upstream);
491 
492 /**
493  * sfp_unregister_upstream() - Unregister sfp bus
494  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
495  *
496  * Unregister a previously registered upstream connection for the SFP
497  * module. @bus is returned from sfp_register_upstream().
498  */
499 void sfp_unregister_upstream(struct sfp_bus *bus)
500 {
501 	rtnl_lock();
502 	if (bus->sfp)
503 		sfp_unregister_bus(bus);
504 	sfp_upstream_clear(bus);
505 	rtnl_unlock();
506 
507 	sfp_bus_put(bus);
508 }
509 EXPORT_SYMBOL_GPL(sfp_unregister_upstream);
510 
511 /* Socket driver entry points */
512 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
513 {
514 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
515 	int ret = 0;
516 
517 	if (ops && ops->connect_phy)
518 		ret = ops->connect_phy(bus->upstream, phydev);
519 
520 	if (ret == 0)
521 		bus->phydev = phydev;
522 
523 	return ret;
524 }
525 EXPORT_SYMBOL_GPL(sfp_add_phy);
526 
527 void sfp_remove_phy(struct sfp_bus *bus)
528 {
529 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
530 
531 	if (ops && ops->disconnect_phy)
532 		ops->disconnect_phy(bus->upstream);
533 	bus->phydev = NULL;
534 }
535 EXPORT_SYMBOL_GPL(sfp_remove_phy);
536 
537 void sfp_link_up(struct sfp_bus *bus)
538 {
539 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
540 
541 	if (ops && ops->link_up)
542 		ops->link_up(bus->upstream);
543 }
544 EXPORT_SYMBOL_GPL(sfp_link_up);
545 
546 void sfp_link_down(struct sfp_bus *bus)
547 {
548 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
549 
550 	if (ops && ops->link_down)
551 		ops->link_down(bus->upstream);
552 }
553 EXPORT_SYMBOL_GPL(sfp_link_down);
554 
555 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
556 {
557 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
558 	int ret = 0;
559 
560 	if (ops && ops->module_insert)
561 		ret = ops->module_insert(bus->upstream, id);
562 
563 	return ret;
564 }
565 EXPORT_SYMBOL_GPL(sfp_module_insert);
566 
567 void sfp_module_remove(struct sfp_bus *bus)
568 {
569 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
570 
571 	if (ops && ops->module_remove)
572 		ops->module_remove(bus->upstream);
573 }
574 EXPORT_SYMBOL_GPL(sfp_module_remove);
575 
576 static void sfp_socket_clear(struct sfp_bus *bus)
577 {
578 	bus->sfp_dev = NULL;
579 	bus->sfp = NULL;
580 	bus->socket_ops = NULL;
581 }
582 
583 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
584 				    const struct sfp_socket_ops *ops)
585 {
586 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
587 	int ret = 0;
588 
589 	if (bus) {
590 		rtnl_lock();
591 		bus->sfp_dev = dev;
592 		bus->sfp = sfp;
593 		bus->socket_ops = ops;
594 
595 		if (bus->netdev) {
596 			ret = sfp_register_bus(bus);
597 			if (ret)
598 				sfp_socket_clear(bus);
599 		}
600 		rtnl_unlock();
601 	}
602 
603 	if (ret) {
604 		sfp_bus_put(bus);
605 		bus = NULL;
606 	}
607 
608 	return bus;
609 }
610 EXPORT_SYMBOL_GPL(sfp_register_socket);
611 
612 void sfp_unregister_socket(struct sfp_bus *bus)
613 {
614 	rtnl_lock();
615 	if (bus->netdev)
616 		sfp_unregister_bus(bus);
617 	sfp_socket_clear(bus);
618 	rtnl_unlock();
619 
620 	sfp_bus_put(bus);
621 }
622 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
623