xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision 26ba4e57) 
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 phy_device *phydev;
28 
29 	bool registered;
30 	bool started;
31 };
32 
33 /**
34  * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
35  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
36  * @id: a pointer to the module's &struct sfp_eeprom_id
37  * @support: optional pointer to an array of unsigned long for the
38  *   ethtool support mask
39  *
40  * Parse the EEPROM identification given in @id, and return one of
41  * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
42  * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
43  * the connector type.
44  *
45  * If the port type is not known, returns %PORT_OTHER.
46  */
47 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
48 		   unsigned long *support)
49 {
50 	int port;
51 
52 	/* port is the physical connector, set this from the connector field. */
53 	switch (id->base.connector) {
54 	case SFP_CONNECTOR_SC:
55 	case SFP_CONNECTOR_FIBERJACK:
56 	case SFP_CONNECTOR_LC:
57 	case SFP_CONNECTOR_MT_RJ:
58 	case SFP_CONNECTOR_MU:
59 	case SFP_CONNECTOR_OPTICAL_PIGTAIL:
60 		port = PORT_FIBRE;
61 		break;
62 
63 	case SFP_CONNECTOR_RJ45:
64 		port = PORT_TP;
65 		break;
66 
67 	case SFP_CONNECTOR_COPPER_PIGTAIL:
68 		port = PORT_DA;
69 		break;
70 
71 	case SFP_CONNECTOR_UNSPEC:
72 		if (id->base.e1000_base_t) {
73 			port = PORT_TP;
74 			break;
75 		}
76 		/* fallthrough */
77 	case SFP_CONNECTOR_SG: /* guess */
78 	case SFP_CONNECTOR_MPO_1X12:
79 	case SFP_CONNECTOR_MPO_2X16:
80 	case SFP_CONNECTOR_HSSDC_II:
81 	case SFP_CONNECTOR_NOSEPARATE:
82 	case SFP_CONNECTOR_MXC_2X16:
83 		port = PORT_OTHER;
84 		break;
85 	default:
86 		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
87 			 id->base.connector);
88 		port = PORT_OTHER;
89 		break;
90 	}
91 
92 	if (support) {
93 		switch (port) {
94 		case PORT_FIBRE:
95 			phylink_set(support, FIBRE);
96 			break;
97 
98 		case PORT_TP:
99 			phylink_set(support, TP);
100 			break;
101 		}
102 	}
103 
104 	return port;
105 }
106 EXPORT_SYMBOL_GPL(sfp_parse_port);
107 
108 /**
109  * sfp_parse_support() - Parse the eeprom id for supported link modes
110  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
111  * @id: a pointer to the module's &struct sfp_eeprom_id
112  * @support: pointer to an array of unsigned long for the ethtool support mask
113  *
114  * Parse the EEPROM identification information and derive the supported
115  * ethtool link modes for the module.
116  */
117 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
118 		       unsigned long *support)
119 {
120 	unsigned int br_min, br_nom, br_max;
121 	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
122 
123 	/* Decode the bitrate information to MBd */
124 	br_min = br_nom = br_max = 0;
125 	if (id->base.br_nominal) {
126 		if (id->base.br_nominal != 255) {
127 			br_nom = id->base.br_nominal * 100;
128 			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
129 			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
130 		} else if (id->ext.br_max) {
131 			br_nom = 250 * id->ext.br_max;
132 			br_max = br_nom + br_nom * id->ext.br_min / 100;
133 			br_min = br_nom - br_nom * id->ext.br_min / 100;
134 		}
135 
136 		/* When using passive cables, in case neither BR,min nor BR,max
137 		 * are specified, set br_min to 0 as the nominal value is then
138 		 * used as the maximum.
139 		 */
140 		if (br_min == br_max && id->base.sfp_ct_passive)
141 			br_min = 0;
142 	}
143 
144 	/* Set ethtool support from the compliance fields. */
145 	if (id->base.e10g_base_sr)
146 		phylink_set(modes, 10000baseSR_Full);
147 	if (id->base.e10g_base_lr)
148 		phylink_set(modes, 10000baseLR_Full);
149 	if (id->base.e10g_base_lrm)
150 		phylink_set(modes, 10000baseLRM_Full);
151 	if (id->base.e10g_base_er)
152 		phylink_set(modes, 10000baseER_Full);
153 	if (id->base.e1000_base_sx ||
154 	    id->base.e1000_base_lx ||
155 	    id->base.e1000_base_cx)
156 		phylink_set(modes, 1000baseX_Full);
157 	if (id->base.e1000_base_t) {
158 		phylink_set(modes, 1000baseT_Half);
159 		phylink_set(modes, 1000baseT_Full);
160 	}
161 
162 	/* 1000Base-PX or 1000Base-BX10 */
163 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
164 	    br_min <= 1300 && br_max >= 1200)
165 		phylink_set(modes, 1000baseX_Full);
166 
167 	/* For active or passive cables, select the link modes
168 	 * based on the bit rates and the cable compliance bytes.
169 	 */
170 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
171 		/* This may look odd, but some manufacturers use 12000MBd */
172 		if (br_min <= 12000 && br_max >= 10300)
173 			phylink_set(modes, 10000baseCR_Full);
174 		if (br_min <= 3200 && br_max >= 3100)
175 			phylink_set(modes, 2500baseX_Full);
176 		if (br_min <= 1300 && br_max >= 1200)
177 			phylink_set(modes, 1000baseX_Full);
178 	}
179 	if (id->base.sfp_ct_passive) {
180 		if (id->base.passive.sff8431_app_e)
181 			phylink_set(modes, 10000baseCR_Full);
182 	}
183 	if (id->base.sfp_ct_active) {
184 		if (id->base.active.sff8431_app_e ||
185 		    id->base.active.sff8431_lim) {
186 			phylink_set(modes, 10000baseCR_Full);
187 		}
188 	}
189 
190 	switch (id->base.extended_cc) {
191 	case 0x00: /* Unspecified */
192 		break;
193 	case 0x02: /* 100Gbase-SR4 or 25Gbase-SR */
194 		phylink_set(modes, 100000baseSR4_Full);
195 		phylink_set(modes, 25000baseSR_Full);
196 		break;
197 	case 0x03: /* 100Gbase-LR4 or 25Gbase-LR */
198 	case 0x04: /* 100Gbase-ER4 or 25Gbase-ER */
199 		phylink_set(modes, 100000baseLR4_ER4_Full);
200 		break;
201 	case 0x0b: /* 100Gbase-CR4 or 25Gbase-CR CA-L */
202 	case 0x0c: /* 25Gbase-CR CA-S */
203 	case 0x0d: /* 25Gbase-CR CA-N */
204 		phylink_set(modes, 100000baseCR4_Full);
205 		phylink_set(modes, 25000baseCR_Full);
206 		break;
207 	default:
208 		dev_warn(bus->sfp_dev,
209 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
210 			 id->base.extended_cc);
211 		break;
212 	}
213 
214 	/* For fibre channel SFP, derive possible BaseX modes */
215 	if (id->base.fc_speed_100 ||
216 	    id->base.fc_speed_200 ||
217 	    id->base.fc_speed_400) {
218 		if (id->base.br_nominal >= 31)
219 			phylink_set(modes, 2500baseX_Full);
220 		if (id->base.br_nominal >= 12)
221 			phylink_set(modes, 1000baseX_Full);
222 	}
223 
224 	/* If we haven't discovered any modes that this module supports, try
225 	 * the encoding and bitrate to determine supported modes. Some BiDi
226 	 * modules (eg, 1310nm/1550nm) are not 1000BASE-BX compliant due to
227 	 * the differing wavelengths, so do not set any transceiver bits.
228 	 */
229 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS)) {
230 		/* If the encoding and bit rate allows 1000baseX */
231 		if (id->base.encoding == SFP_ENCODING_8B10B && br_nom &&
232 		    br_min <= 1300 && br_max >= 1200)
233 			phylink_set(modes, 1000baseX_Full);
234 	}
235 
236 	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
237 
238 	phylink_set(support, Autoneg);
239 	phylink_set(support, Pause);
240 	phylink_set(support, Asym_Pause);
241 }
242 EXPORT_SYMBOL_GPL(sfp_parse_support);
243 
244 /**
245  * sfp_select_interface() - Select appropriate phy_interface_t mode
246  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
247  * @id: a pointer to the module's &struct sfp_eeprom_id
248  * @link_modes: ethtool link modes mask
249  *
250  * Derive the phy_interface_t mode for the information found in the
251  * module's identifying EEPROM and the link modes mask. There is no
252  * standard or defined way to derive this information, so we decide
253  * based upon the link mode mask.
254  */
255 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
256 				     const struct sfp_eeprom_id *id,
257 				     unsigned long *link_modes)
258 {
259 	if (phylink_test(link_modes, 10000baseCR_Full) ||
260 	    phylink_test(link_modes, 10000baseSR_Full) ||
261 	    phylink_test(link_modes, 10000baseLR_Full) ||
262 	    phylink_test(link_modes, 10000baseLRM_Full) ||
263 	    phylink_test(link_modes, 10000baseER_Full))
264 		return PHY_INTERFACE_MODE_10GKR;
265 
266 	if (phylink_test(link_modes, 2500baseX_Full))
267 		return PHY_INTERFACE_MODE_2500BASEX;
268 
269 	if (id->base.e1000_base_t ||
270 	    id->base.e100_base_lx ||
271 	    id->base.e100_base_fx)
272 		return PHY_INTERFACE_MODE_SGMII;
273 
274 	if (phylink_test(link_modes, 1000baseX_Full))
275 		return PHY_INTERFACE_MODE_1000BASEX;
276 
277 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
278 
279 	return PHY_INTERFACE_MODE_NA;
280 }
281 EXPORT_SYMBOL_GPL(sfp_select_interface);
282 
283 static LIST_HEAD(sfp_buses);
284 static DEFINE_MUTEX(sfp_mutex);
285 
286 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
287 {
288 	return bus->registered ? bus->upstream_ops : NULL;
289 }
290 
291 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
292 {
293 	struct sfp_bus *sfp, *new, *found = NULL;
294 
295 	new = kzalloc(sizeof(*new), GFP_KERNEL);
296 
297 	mutex_lock(&sfp_mutex);
298 
299 	list_for_each_entry(sfp, &sfp_buses, node) {
300 		if (sfp->fwnode == fwnode) {
301 			kref_get(&sfp->kref);
302 			found = sfp;
303 			break;
304 		}
305 	}
306 
307 	if (!found && new) {
308 		kref_init(&new->kref);
309 		new->fwnode = fwnode;
310 		list_add(&new->node, &sfp_buses);
311 		found = new;
312 		new = NULL;
313 	}
314 
315 	mutex_unlock(&sfp_mutex);
316 
317 	kfree(new);
318 
319 	return found;
320 }
321 
322 static void sfp_bus_release(struct kref *kref)
323 {
324 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
325 
326 	list_del(&bus->node);
327 	mutex_unlock(&sfp_mutex);
328 	kfree(bus);
329 }
330 
331 static void sfp_bus_put(struct sfp_bus *bus)
332 {
333 	kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
334 }
335 
336 static int sfp_register_bus(struct sfp_bus *bus)
337 {
338 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
339 	int ret;
340 
341 	if (ops) {
342 		if (ops->link_down)
343 			ops->link_down(bus->upstream);
344 		if (ops->connect_phy && bus->phydev) {
345 			ret = ops->connect_phy(bus->upstream, bus->phydev);
346 			if (ret)
347 				return ret;
348 		}
349 	}
350 	bus->socket_ops->attach(bus->sfp);
351 	if (bus->started)
352 		bus->socket_ops->start(bus->sfp);
353 	bus->upstream_ops->attach(bus->upstream, bus);
354 	bus->registered = true;
355 	return 0;
356 }
357 
358 static void sfp_unregister_bus(struct sfp_bus *bus)
359 {
360 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
361 
362 	if (bus->registered) {
363 		bus->upstream_ops->detach(bus->upstream, bus);
364 		if (bus->started)
365 			bus->socket_ops->stop(bus->sfp);
366 		bus->socket_ops->detach(bus->sfp);
367 		if (bus->phydev && ops && ops->disconnect_phy)
368 			ops->disconnect_phy(bus->upstream);
369 	}
370 	bus->registered = false;
371 }
372 
373 /**
374  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
375  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
376  * @modinfo: a &struct ethtool_modinfo
377  *
378  * Fill in the type and eeprom_len parameters in @modinfo for a module on
379  * the sfp bus specified by @bus.
380  *
381  * Returns 0 on success or a negative errno number.
382  */
383 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
384 {
385 	return bus->socket_ops->module_info(bus->sfp, modinfo);
386 }
387 EXPORT_SYMBOL_GPL(sfp_get_module_info);
388 
389 /**
390  * sfp_get_module_eeprom() - Read the SFP module EEPROM
391  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
392  * @ee: a &struct ethtool_eeprom
393  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
394  *
395  * Read the EEPROM as specified by the supplied @ee. See the documentation
396  * for &struct ethtool_eeprom for the region to be read.
397  *
398  * Returns 0 on success or a negative errno number.
399  */
400 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
401 			  u8 *data)
402 {
403 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
404 }
405 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
406 
407 /**
408  * sfp_upstream_start() - Inform the SFP that the network device is up
409  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
410  *
411  * Inform the SFP socket that the network device is now up, so that the
412  * module can be enabled by allowing TX_DISABLE to be deasserted. This
413  * should be called from the network device driver's &struct net_device_ops
414  * ndo_open() method.
415  */
416 void sfp_upstream_start(struct sfp_bus *bus)
417 {
418 	if (bus->registered)
419 		bus->socket_ops->start(bus->sfp);
420 	bus->started = true;
421 }
422 EXPORT_SYMBOL_GPL(sfp_upstream_start);
423 
424 /**
425  * sfp_upstream_stop() - Inform the SFP that the network device is down
426  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
427  *
428  * Inform the SFP socket that the network device is now up, so that the
429  * module can be disabled by asserting TX_DISABLE, disabling the laser
430  * in optical modules. This should be called from the network device
431  * driver's &struct net_device_ops ndo_stop() method.
432  */
433 void sfp_upstream_stop(struct sfp_bus *bus)
434 {
435 	if (bus->registered)
436 		bus->socket_ops->stop(bus->sfp);
437 	bus->started = false;
438 }
439 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
440 
441 static void sfp_upstream_clear(struct sfp_bus *bus)
442 {
443 	bus->upstream_ops = NULL;
444 	bus->upstream = NULL;
445 }
446 
447 /**
448  * sfp_register_upstream() - Register the neighbouring device
449  * @fwnode: firmware node for the SFP bus
450  * @upstream: the upstream private data
451  * @ops: the upstream's &struct sfp_upstream_ops
452  *
453  * Register the upstream device (eg, PHY) with the SFP bus. MAC drivers
454  * should use phylink, which will call this function for them. Returns
455  * a pointer to the allocated &struct sfp_bus.
456  *
457  * On error, returns %NULL.
458  */
459 struct sfp_bus *sfp_register_upstream(struct fwnode_handle *fwnode,
460 				      void *upstream,
461 				      const struct sfp_upstream_ops *ops)
462 {
463 	struct sfp_bus *bus = sfp_bus_get(fwnode);
464 	int ret = 0;
465 
466 	if (bus) {
467 		rtnl_lock();
468 		bus->upstream_ops = ops;
469 		bus->upstream = upstream;
470 
471 		if (bus->sfp) {
472 			ret = sfp_register_bus(bus);
473 			if (ret)
474 				sfp_upstream_clear(bus);
475 		}
476 		rtnl_unlock();
477 	}
478 
479 	if (ret) {
480 		sfp_bus_put(bus);
481 		bus = NULL;
482 	}
483 
484 	return bus;
485 }
486 EXPORT_SYMBOL_GPL(sfp_register_upstream);
487 
488 /**
489  * sfp_unregister_upstream() - Unregister sfp bus
490  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
491  *
492  * Unregister a previously registered upstream connection for the SFP
493  * module. @bus is returned from sfp_register_upstream().
494  */
495 void sfp_unregister_upstream(struct sfp_bus *bus)
496 {
497 	rtnl_lock();
498 	if (bus->sfp)
499 		sfp_unregister_bus(bus);
500 	sfp_upstream_clear(bus);
501 	rtnl_unlock();
502 
503 	sfp_bus_put(bus);
504 }
505 EXPORT_SYMBOL_GPL(sfp_unregister_upstream);
506 
507 /* Socket driver entry points */
508 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
509 {
510 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
511 	int ret = 0;
512 
513 	if (ops && ops->connect_phy)
514 		ret = ops->connect_phy(bus->upstream, phydev);
515 
516 	if (ret == 0)
517 		bus->phydev = phydev;
518 
519 	return ret;
520 }
521 EXPORT_SYMBOL_GPL(sfp_add_phy);
522 
523 void sfp_remove_phy(struct sfp_bus *bus)
524 {
525 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
526 
527 	if (ops && ops->disconnect_phy)
528 		ops->disconnect_phy(bus->upstream);
529 	bus->phydev = NULL;
530 }
531 EXPORT_SYMBOL_GPL(sfp_remove_phy);
532 
533 void sfp_link_up(struct sfp_bus *bus)
534 {
535 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
536 
537 	if (ops && ops->link_up)
538 		ops->link_up(bus->upstream);
539 }
540 EXPORT_SYMBOL_GPL(sfp_link_up);
541 
542 void sfp_link_down(struct sfp_bus *bus)
543 {
544 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
545 
546 	if (ops && ops->link_down)
547 		ops->link_down(bus->upstream);
548 }
549 EXPORT_SYMBOL_GPL(sfp_link_down);
550 
551 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
552 {
553 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
554 	int ret = 0;
555 
556 	if (ops && ops->module_insert)
557 		ret = ops->module_insert(bus->upstream, id);
558 
559 	return ret;
560 }
561 EXPORT_SYMBOL_GPL(sfp_module_insert);
562 
563 void sfp_module_remove(struct sfp_bus *bus)
564 {
565 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
566 
567 	if (ops && ops->module_remove)
568 		ops->module_remove(bus->upstream);
569 }
570 EXPORT_SYMBOL_GPL(sfp_module_remove);
571 
572 static void sfp_socket_clear(struct sfp_bus *bus)
573 {
574 	bus->sfp_dev = NULL;
575 	bus->sfp = NULL;
576 	bus->socket_ops = NULL;
577 }
578 
579 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
580 				    const struct sfp_socket_ops *ops)
581 {
582 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
583 	int ret = 0;
584 
585 	if (bus) {
586 		rtnl_lock();
587 		bus->sfp_dev = dev;
588 		bus->sfp = sfp;
589 		bus->socket_ops = ops;
590 
591 		if (bus->upstream_ops) {
592 			ret = sfp_register_bus(bus);
593 			if (ret)
594 				sfp_socket_clear(bus);
595 		}
596 		rtnl_unlock();
597 	}
598 
599 	if (ret) {
600 		sfp_bus_put(bus);
601 		bus = NULL;
602 	}
603 
604 	return bus;
605 }
606 EXPORT_SYMBOL_GPL(sfp_register_socket);
607 
608 void sfp_unregister_socket(struct sfp_bus *bus)
609 {
610 	rtnl_lock();
611 	if (bus->upstream_ops)
612 		sfp_unregister_bus(bus);
613 	sfp_socket_clear(bus);
614 	rtnl_unlock();
615 
616 	sfp_bus_put(bus);
617 }
618 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
619