xref: /openbmc/linux/drivers/net/phy/sfp-bus.c (revision addee42a)
1 #include <linux/export.h>
2 #include <linux/kref.h>
3 #include <linux/list.h>
4 #include <linux/mutex.h>
5 #include <linux/phylink.h>
6 #include <linux/rtnetlink.h>
7 #include <linux/slab.h>
8 
9 #include "sfp.h"
10 
11 /**
12  * struct sfp_bus - internal representation of a sfp bus
13  */
14 struct sfp_bus {
15 	/* private: */
16 	struct kref kref;
17 	struct list_head node;
18 	struct fwnode_handle *fwnode;
19 
20 	const struct sfp_socket_ops *socket_ops;
21 	struct device *sfp_dev;
22 	struct sfp *sfp;
23 
24 	const struct sfp_upstream_ops *upstream_ops;
25 	void *upstream;
26 	struct net_device *netdev;
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 
137 	/* Set ethtool support from the compliance fields. */
138 	if (id->base.e10g_base_sr)
139 		phylink_set(modes, 10000baseSR_Full);
140 	if (id->base.e10g_base_lr)
141 		phylink_set(modes, 10000baseLR_Full);
142 	if (id->base.e10g_base_lrm)
143 		phylink_set(modes, 10000baseLRM_Full);
144 	if (id->base.e10g_base_er)
145 		phylink_set(modes, 10000baseER_Full);
146 	if (id->base.e1000_base_sx ||
147 	    id->base.e1000_base_lx ||
148 	    id->base.e1000_base_cx)
149 		phylink_set(modes, 1000baseX_Full);
150 	if (id->base.e1000_base_t) {
151 		phylink_set(modes, 1000baseT_Half);
152 		phylink_set(modes, 1000baseT_Full);
153 	}
154 
155 	/* 1000Base-PX or 1000Base-BX10 */
156 	if ((id->base.e_base_px || id->base.e_base_bx10) &&
157 	    br_min <= 1300 && br_max >= 1200)
158 		phylink_set(support, 1000baseX_Full);
159 
160 	/* For active or passive cables, select the link modes
161 	 * based on the bit rates and the cable compliance bytes.
162 	 */
163 	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
164 		/* This may look odd, but some manufacturers use 12000MBd */
165 		if (br_min <= 12000 && br_max >= 10300)
166 			phylink_set(modes, 10000baseCR_Full);
167 		if (br_min <= 3200 && br_max >= 3100)
168 			phylink_set(modes, 2500baseX_Full);
169 		if (br_min <= 1300 && br_max >= 1200)
170 			phylink_set(modes, 1000baseX_Full);
171 	}
172 	if (id->base.sfp_ct_passive) {
173 		if (id->base.passive.sff8431_app_e)
174 			phylink_set(modes, 10000baseCR_Full);
175 	}
176 	if (id->base.sfp_ct_active) {
177 		if (id->base.active.sff8431_app_e ||
178 		    id->base.active.sff8431_lim) {
179 			phylink_set(modes, 10000baseCR_Full);
180 		}
181 	}
182 
183 	switch (id->base.extended_cc) {
184 	case 0x00: /* Unspecified */
185 		break;
186 	case 0x02: /* 100Gbase-SR4 or 25Gbase-SR */
187 		phylink_set(modes, 100000baseSR4_Full);
188 		phylink_set(modes, 25000baseSR_Full);
189 		break;
190 	case 0x03: /* 100Gbase-LR4 or 25Gbase-LR */
191 	case 0x04: /* 100Gbase-ER4 or 25Gbase-ER */
192 		phylink_set(modes, 100000baseLR4_ER4_Full);
193 		break;
194 	case 0x0b: /* 100Gbase-CR4 or 25Gbase-CR CA-L */
195 	case 0x0c: /* 25Gbase-CR CA-S */
196 	case 0x0d: /* 25Gbase-CR CA-N */
197 		phylink_set(modes, 100000baseCR4_Full);
198 		phylink_set(modes, 25000baseCR_Full);
199 		break;
200 	default:
201 		dev_warn(bus->sfp_dev,
202 			 "Unknown/unsupported extended compliance code: 0x%02x\n",
203 			 id->base.extended_cc);
204 		break;
205 	}
206 
207 	/* For fibre channel SFP, derive possible BaseX modes */
208 	if (id->base.fc_speed_100 ||
209 	    id->base.fc_speed_200 ||
210 	    id->base.fc_speed_400) {
211 		if (id->base.br_nominal >= 31)
212 			phylink_set(modes, 2500baseX_Full);
213 		if (id->base.br_nominal >= 12)
214 			phylink_set(modes, 1000baseX_Full);
215 	}
216 
217 	/* If we haven't discovered any modes that this module supports, try
218 	 * the encoding and bitrate to determine supported modes. Some BiDi
219 	 * modules (eg, 1310nm/1550nm) are not 1000BASE-BX compliant due to
220 	 * the differing wavelengths, so do not set any transceiver bits.
221 	 */
222 	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS)) {
223 		/* If the encoding and bit rate allows 1000baseX */
224 		if (id->base.encoding == SFP_ENCODING_8B10B && br_nom &&
225 		    br_min <= 1300 && br_max >= 1200)
226 			phylink_set(modes, 1000baseX_Full);
227 	}
228 
229 	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
230 
231 	phylink_set(support, Autoneg);
232 	phylink_set(support, Pause);
233 	phylink_set(support, Asym_Pause);
234 }
235 EXPORT_SYMBOL_GPL(sfp_parse_support);
236 
237 /**
238  * sfp_select_interface() - Select appropriate phy_interface_t mode
239  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
240  * @id: a pointer to the module's &struct sfp_eeprom_id
241  * @link_modes: ethtool link modes mask
242  *
243  * Derive the phy_interface_t mode for the information found in the
244  * module's identifying EEPROM and the link modes mask. There is no
245  * standard or defined way to derive this information, so we decide
246  * based upon the link mode mask.
247  */
248 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
249 				     const struct sfp_eeprom_id *id,
250 				     unsigned long *link_modes)
251 {
252 	if (phylink_test(link_modes, 10000baseCR_Full) ||
253 	    phylink_test(link_modes, 10000baseSR_Full) ||
254 	    phylink_test(link_modes, 10000baseLR_Full) ||
255 	    phylink_test(link_modes, 10000baseLRM_Full) ||
256 	    phylink_test(link_modes, 10000baseER_Full))
257 		return PHY_INTERFACE_MODE_10GKR;
258 
259 	if (phylink_test(link_modes, 2500baseX_Full))
260 		return PHY_INTERFACE_MODE_2500BASEX;
261 
262 	if (id->base.e1000_base_t ||
263 	    id->base.e100_base_lx ||
264 	    id->base.e100_base_fx)
265 		return PHY_INTERFACE_MODE_SGMII;
266 
267 	if (phylink_test(link_modes, 1000baseX_Full))
268 		return PHY_INTERFACE_MODE_1000BASEX;
269 
270 	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
271 
272 	return PHY_INTERFACE_MODE_NA;
273 }
274 EXPORT_SYMBOL_GPL(sfp_select_interface);
275 
276 static LIST_HEAD(sfp_buses);
277 static DEFINE_MUTEX(sfp_mutex);
278 
279 static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
280 {
281 	return bus->registered ? bus->upstream_ops : NULL;
282 }
283 
284 static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
285 {
286 	struct sfp_bus *sfp, *new, *found = NULL;
287 
288 	new = kzalloc(sizeof(*new), GFP_KERNEL);
289 
290 	mutex_lock(&sfp_mutex);
291 
292 	list_for_each_entry(sfp, &sfp_buses, node) {
293 		if (sfp->fwnode == fwnode) {
294 			kref_get(&sfp->kref);
295 			found = sfp;
296 			break;
297 		}
298 	}
299 
300 	if (!found && new) {
301 		kref_init(&new->kref);
302 		new->fwnode = fwnode;
303 		list_add(&new->node, &sfp_buses);
304 		found = new;
305 		new = NULL;
306 	}
307 
308 	mutex_unlock(&sfp_mutex);
309 
310 	kfree(new);
311 
312 	return found;
313 }
314 
315 static void sfp_bus_release(struct kref *kref)
316 {
317 	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
318 
319 	list_del(&bus->node);
320 	mutex_unlock(&sfp_mutex);
321 	kfree(bus);
322 }
323 
324 static void sfp_bus_put(struct sfp_bus *bus)
325 {
326 	kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
327 }
328 
329 static int sfp_register_bus(struct sfp_bus *bus)
330 {
331 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
332 	int ret;
333 
334 	if (ops) {
335 		if (ops->link_down)
336 			ops->link_down(bus->upstream);
337 		if (ops->connect_phy && bus->phydev) {
338 			ret = ops->connect_phy(bus->upstream, bus->phydev);
339 			if (ret)
340 				return ret;
341 		}
342 	}
343 	if (bus->started)
344 		bus->socket_ops->start(bus->sfp);
345 	bus->netdev->sfp_bus = bus;
346 	bus->registered = true;
347 	return 0;
348 }
349 
350 static void sfp_unregister_bus(struct sfp_bus *bus)
351 {
352 	const struct sfp_upstream_ops *ops = bus->upstream_ops;
353 
354 	if (bus->registered) {
355 		if (bus->started)
356 			bus->socket_ops->stop(bus->sfp);
357 		if (bus->phydev && ops && ops->disconnect_phy)
358 			ops->disconnect_phy(bus->upstream);
359 	}
360 	bus->netdev->sfp_bus = NULL;
361 	bus->registered = false;
362 }
363 
364 /**
365  * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
366  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
367  * @modinfo: a &struct ethtool_modinfo
368  *
369  * Fill in the type and eeprom_len parameters in @modinfo for a module on
370  * the sfp bus specified by @bus.
371  *
372  * Returns 0 on success or a negative errno number.
373  */
374 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
375 {
376 	return bus->socket_ops->module_info(bus->sfp, modinfo);
377 }
378 EXPORT_SYMBOL_GPL(sfp_get_module_info);
379 
380 /**
381  * sfp_get_module_eeprom() - Read the SFP module EEPROM
382  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
383  * @ee: a &struct ethtool_eeprom
384  * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
385  *
386  * Read the EEPROM as specified by the supplied @ee. See the documentation
387  * for &struct ethtool_eeprom for the region to be read.
388  *
389  * Returns 0 on success or a negative errno number.
390  */
391 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
392 			  u8 *data)
393 {
394 	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
395 }
396 EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
397 
398 /**
399  * sfp_upstream_start() - Inform the SFP that the network device is up
400  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
401  *
402  * Inform the SFP socket that the network device is now up, so that the
403  * module can be enabled by allowing TX_DISABLE to be deasserted. This
404  * should be called from the network device driver's &struct net_device_ops
405  * ndo_open() method.
406  */
407 void sfp_upstream_start(struct sfp_bus *bus)
408 {
409 	if (bus->registered)
410 		bus->socket_ops->start(bus->sfp);
411 	bus->started = true;
412 }
413 EXPORT_SYMBOL_GPL(sfp_upstream_start);
414 
415 /**
416  * sfp_upstream_stop() - Inform the SFP that the network device is down
417  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
418  *
419  * Inform the SFP socket that the network device is now up, so that the
420  * module can be disabled by asserting TX_DISABLE, disabling the laser
421  * in optical modules. This should be called from the network device
422  * driver's &struct net_device_ops ndo_stop() method.
423  */
424 void sfp_upstream_stop(struct sfp_bus *bus)
425 {
426 	if (bus->registered)
427 		bus->socket_ops->stop(bus->sfp);
428 	bus->started = false;
429 }
430 EXPORT_SYMBOL_GPL(sfp_upstream_stop);
431 
432 /**
433  * sfp_register_upstream() - Register the neighbouring device
434  * @fwnode: firmware node for the SFP bus
435  * @ndev: network device associated with the interface
436  * @upstream: the upstream private data
437  * @ops: the upstream's &struct sfp_upstream_ops
438  *
439  * Register the upstream device (eg, PHY) with the SFP bus. MAC drivers
440  * should use phylink, which will call this function for them. Returns
441  * a pointer to the allocated &struct sfp_bus.
442  *
443  * On error, returns %NULL.
444  */
445 struct sfp_bus *sfp_register_upstream(struct fwnode_handle *fwnode,
446 				      struct net_device *ndev, void *upstream,
447 				      const struct sfp_upstream_ops *ops)
448 {
449 	struct sfp_bus *bus = sfp_bus_get(fwnode);
450 	int ret = 0;
451 
452 	if (bus) {
453 		rtnl_lock();
454 		bus->upstream_ops = ops;
455 		bus->upstream = upstream;
456 		bus->netdev = ndev;
457 
458 		if (bus->sfp)
459 			ret = sfp_register_bus(bus);
460 		rtnl_unlock();
461 	}
462 
463 	if (ret) {
464 		sfp_bus_put(bus);
465 		bus = NULL;
466 	}
467 
468 	return bus;
469 }
470 EXPORT_SYMBOL_GPL(sfp_register_upstream);
471 
472 /**
473  * sfp_unregister_upstream() - Unregister sfp bus
474  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
475  *
476  * Unregister a previously registered upstream connection for the SFP
477  * module. @bus is returned from sfp_register_upstream().
478  */
479 void sfp_unregister_upstream(struct sfp_bus *bus)
480 {
481 	rtnl_lock();
482 	if (bus->sfp)
483 		sfp_unregister_bus(bus);
484 	bus->upstream = NULL;
485 	bus->netdev = NULL;
486 	rtnl_unlock();
487 
488 	sfp_bus_put(bus);
489 }
490 EXPORT_SYMBOL_GPL(sfp_unregister_upstream);
491 
492 /* Socket driver entry points */
493 int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
494 {
495 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
496 	int ret = 0;
497 
498 	if (ops && ops->connect_phy)
499 		ret = ops->connect_phy(bus->upstream, phydev);
500 
501 	if (ret == 0)
502 		bus->phydev = phydev;
503 
504 	return ret;
505 }
506 EXPORT_SYMBOL_GPL(sfp_add_phy);
507 
508 void sfp_remove_phy(struct sfp_bus *bus)
509 {
510 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
511 
512 	if (ops && ops->disconnect_phy)
513 		ops->disconnect_phy(bus->upstream);
514 	bus->phydev = NULL;
515 }
516 EXPORT_SYMBOL_GPL(sfp_remove_phy);
517 
518 void sfp_link_up(struct sfp_bus *bus)
519 {
520 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
521 
522 	if (ops && ops->link_up)
523 		ops->link_up(bus->upstream);
524 }
525 EXPORT_SYMBOL_GPL(sfp_link_up);
526 
527 void sfp_link_down(struct sfp_bus *bus)
528 {
529 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
530 
531 	if (ops && ops->link_down)
532 		ops->link_down(bus->upstream);
533 }
534 EXPORT_SYMBOL_GPL(sfp_link_down);
535 
536 int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
537 {
538 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
539 	int ret = 0;
540 
541 	if (ops && ops->module_insert)
542 		ret = ops->module_insert(bus->upstream, id);
543 
544 	return ret;
545 }
546 EXPORT_SYMBOL_GPL(sfp_module_insert);
547 
548 void sfp_module_remove(struct sfp_bus *bus)
549 {
550 	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
551 
552 	if (ops && ops->module_remove)
553 		ops->module_remove(bus->upstream);
554 }
555 EXPORT_SYMBOL_GPL(sfp_module_remove);
556 
557 struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
558 				    const struct sfp_socket_ops *ops)
559 {
560 	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
561 	int ret = 0;
562 
563 	if (bus) {
564 		rtnl_lock();
565 		bus->sfp_dev = dev;
566 		bus->sfp = sfp;
567 		bus->socket_ops = ops;
568 
569 		if (bus->netdev)
570 			ret = sfp_register_bus(bus);
571 		rtnl_unlock();
572 	}
573 
574 	if (ret) {
575 		sfp_bus_put(bus);
576 		bus = NULL;
577 	}
578 
579 	return bus;
580 }
581 EXPORT_SYMBOL_GPL(sfp_register_socket);
582 
583 void sfp_unregister_socket(struct sfp_bus *bus)
584 {
585 	rtnl_lock();
586 	if (bus->netdev)
587 		sfp_unregister_bus(bus);
588 	bus->sfp_dev = NULL;
589 	bus->sfp = NULL;
590 	bus->socket_ops = NULL;
591 	rtnl_unlock();
592 
593 	sfp_bus_put(bus);
594 }
595 EXPORT_SYMBOL_GPL(sfp_unregister_socket);
596