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
13struct sfp_quirk {
14	const char *vendor;
15	const char *part;
16	void (*modes)(const struct sfp_eeprom_id *id, unsigned long *modes);
17};
18
19/**
20 * struct sfp_bus - internal representation of a sfp bus
21 */
22struct sfp_bus {
23	/* private: */
24	struct kref kref;
25	struct list_head node;
26	struct fwnode_handle *fwnode;
27
28	const struct sfp_socket_ops *socket_ops;
29	struct device *sfp_dev;
30	struct sfp *sfp;
31	const struct sfp_quirk *sfp_quirk;
32
33	const struct sfp_upstream_ops *upstream_ops;
34	void *upstream;
35	struct phy_device *phydev;
36
37	bool registered;
38	bool started;
39};
40
41static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id,
42				unsigned long *modes)
43{
44	phylink_set(modes, 2500baseX_Full);
45}
46
47static void sfp_quirk_ubnt_uf_instant(const struct sfp_eeprom_id *id,
48				      unsigned long *modes)
49{
50	/* Ubiquiti U-Fiber Instant module claims that support all transceiver
51	 * types including 10G Ethernet which is not truth. So clear all claimed
52	 * modes and set only one mode which module supports: 1000baseX_Full.
53	 */
54	phylink_zero(modes);
55	phylink_set(modes, 1000baseX_Full);
56}
57
58static const struct sfp_quirk sfp_quirks[] = {
59	{
60		// Alcatel Lucent G-010S-P can operate at 2500base-X, but
61		// incorrectly report 2500MBd NRZ in their EEPROM
62		.vendor = "ALCATELLUCENT",
63		.part = "G010SP",
64		.modes = sfp_quirk_2500basex,
65	}, {
66		// Alcatel Lucent G-010S-A can operate at 2500base-X, but
67		// report 3.2GBd NRZ in their EEPROM
68		.vendor = "ALCATELLUCENT",
69		.part = "3FE46541AA",
70		.modes = sfp_quirk_2500basex,
71	}, {
72		// Huawei MA5671A can operate at 2500base-X, but report 1.2GBd
73		// NRZ in their EEPROM
74		.vendor = "HUAWEI",
75		.part = "MA5671A",
76		.modes = sfp_quirk_2500basex,
77	}, {
78		// Lantech 8330-262D-E can operate at 2500base-X, but
79		// incorrectly report 2500MBd NRZ in their EEPROM
80		.vendor = "Lantech",
81		.part = "8330-262D-E",
82		.modes = sfp_quirk_2500basex,
83	}, {
84		.vendor = "UBNT",
85		.part = "UF-INSTANT",
86		.modes = sfp_quirk_ubnt_uf_instant,
87	},
88};
89
90static size_t sfp_strlen(const char *str, size_t maxlen)
91{
92	size_t size, i;
93
94	/* Trailing characters should be filled with space chars */
95	for (i = 0, size = 0; i < maxlen; i++)
96		if (str[i] != ' ')
97			size = i + 1;
98
99	return size;
100}
101
102static bool sfp_match(const char *qs, const char *str, size_t len)
103{
104	if (!qs)
105		return true;
106	if (strlen(qs) != len)
107		return false;
108	return !strncmp(qs, str, len);
109}
110
111static const struct sfp_quirk *sfp_lookup_quirk(const struct sfp_eeprom_id *id)
112{
113	const struct sfp_quirk *q;
114	unsigned int i;
115	size_t vs, ps;
116
117	vs = sfp_strlen(id->base.vendor_name, ARRAY_SIZE(id->base.vendor_name));
118	ps = sfp_strlen(id->base.vendor_pn, ARRAY_SIZE(id->base.vendor_pn));
119
120	for (i = 0, q = sfp_quirks; i < ARRAY_SIZE(sfp_quirks); i++, q++)
121		if (sfp_match(q->vendor, id->base.vendor_name, vs) &&
122		    sfp_match(q->part, id->base.vendor_pn, ps))
123			return q;
124
125	return NULL;
126}
127
128/**
129 * sfp_parse_port() - Parse the EEPROM base ID, setting the port type
130 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
131 * @id: a pointer to the module's &struct sfp_eeprom_id
132 * @support: optional pointer to an array of unsigned long for the
133 *   ethtool support mask
134 *
135 * Parse the EEPROM identification given in @id, and return one of
136 * %PORT_TP, %PORT_FIBRE or %PORT_OTHER. If @support is non-%NULL,
137 * also set the ethtool %ETHTOOL_LINK_MODE_xxx_BIT corresponding with
138 * the connector type.
139 *
140 * If the port type is not known, returns %PORT_OTHER.
141 */
142int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
143		   unsigned long *support)
144{
145	int port;
146
147	/* port is the physical connector, set this from the connector field. */
148	switch (id->base.connector) {
149	case SFF8024_CONNECTOR_SC:
150	case SFF8024_CONNECTOR_FIBERJACK:
151	case SFF8024_CONNECTOR_LC:
152	case SFF8024_CONNECTOR_MT_RJ:
153	case SFF8024_CONNECTOR_MU:
154	case SFF8024_CONNECTOR_OPTICAL_PIGTAIL:
155	case SFF8024_CONNECTOR_MPO_1X12:
156	case SFF8024_CONNECTOR_MPO_2X16:
157		port = PORT_FIBRE;
158		break;
159
160	case SFF8024_CONNECTOR_RJ45:
161		port = PORT_TP;
162		break;
163
164	case SFF8024_CONNECTOR_COPPER_PIGTAIL:
165		port = PORT_DA;
166		break;
167
168	case SFF8024_CONNECTOR_UNSPEC:
169		if (id->base.e1000_base_t) {
170			port = PORT_TP;
171			break;
172		}
173		fallthrough;
174	case SFF8024_CONNECTOR_SG: /* guess */
175	case SFF8024_CONNECTOR_HSSDC_II:
176	case SFF8024_CONNECTOR_NOSEPARATE:
177	case SFF8024_CONNECTOR_MXC_2X16:
178		port = PORT_OTHER;
179		break;
180	default:
181		dev_warn(bus->sfp_dev, "SFP: unknown connector id 0x%02x\n",
182			 id->base.connector);
183		port = PORT_OTHER;
184		break;
185	}
186
187	if (support) {
188		switch (port) {
189		case PORT_FIBRE:
190			phylink_set(support, FIBRE);
191			break;
192
193		case PORT_TP:
194			phylink_set(support, TP);
195			break;
196		}
197	}
198
199	return port;
200}
201EXPORT_SYMBOL_GPL(sfp_parse_port);
202
203/**
204 * sfp_may_have_phy() - indicate whether the module may have a PHY
205 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
206 * @id: a pointer to the module's &struct sfp_eeprom_id
207 *
208 * Parse the EEPROM identification given in @id, and return whether
209 * this module may have a PHY.
210 */
211bool sfp_may_have_phy(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
212{
213	if (id->base.e1000_base_t)
214		return true;
215
216	if (id->base.phys_id != SFF8024_ID_DWDM_SFP) {
217		switch (id->base.extended_cc) {
218		case SFF8024_ECC_10GBASE_T_SFI:
219		case SFF8024_ECC_10GBASE_T_SR:
220		case SFF8024_ECC_5GBASE_T:
221		case SFF8024_ECC_2_5GBASE_T:
222			return true;
223		}
224	}
225
226	return false;
227}
228EXPORT_SYMBOL_GPL(sfp_may_have_phy);
229
230/**
231 * sfp_parse_support() - Parse the eeprom id for supported link modes
232 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
233 * @id: a pointer to the module's &struct sfp_eeprom_id
234 * @support: pointer to an array of unsigned long for the ethtool support mask
235 *
236 * Parse the EEPROM identification information and derive the supported
237 * ethtool link modes for the module.
238 */
239void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
240		       unsigned long *support)
241{
242	unsigned int br_min, br_nom, br_max;
243	__ETHTOOL_DECLARE_LINK_MODE_MASK(modes) = { 0, };
244
245	/* Decode the bitrate information to MBd */
246	br_min = br_nom = br_max = 0;
247	if (id->base.br_nominal) {
248		if (id->base.br_nominal != 255) {
249			br_nom = id->base.br_nominal * 100;
250			br_min = br_nom - id->base.br_nominal * id->ext.br_min;
251			br_max = br_nom + id->base.br_nominal * id->ext.br_max;
252		} else if (id->ext.br_max) {
253			br_nom = 250 * id->ext.br_max;
254			br_max = br_nom + br_nom * id->ext.br_min / 100;
255			br_min = br_nom - br_nom * id->ext.br_min / 100;
256		}
257
258		/* When using passive cables, in case neither BR,min nor BR,max
259		 * are specified, set br_min to 0 as the nominal value is then
260		 * used as the maximum.
261		 */
262		if (br_min == br_max && id->base.sfp_ct_passive)
263			br_min = 0;
264	}
265
266	/* Set ethtool support from the compliance fields. */
267	if (id->base.e10g_base_sr)
268		phylink_set(modes, 10000baseSR_Full);
269	if (id->base.e10g_base_lr)
270		phylink_set(modes, 10000baseLR_Full);
271	if (id->base.e10g_base_lrm)
272		phylink_set(modes, 10000baseLRM_Full);
273	if (id->base.e10g_base_er)
274		phylink_set(modes, 10000baseER_Full);
275	if (id->base.e1000_base_sx ||
276	    id->base.e1000_base_lx ||
277	    id->base.e1000_base_cx)
278		phylink_set(modes, 1000baseX_Full);
279	if (id->base.e1000_base_t) {
280		phylink_set(modes, 1000baseT_Half);
281		phylink_set(modes, 1000baseT_Full);
282	}
283
284	/* 1000Base-PX or 1000Base-BX10 */
285	if ((id->base.e_base_px || id->base.e_base_bx10) &&
286	    br_min <= 1300 && br_max >= 1200)
287		phylink_set(modes, 1000baseX_Full);
288
289	/* For active or passive cables, select the link modes
290	 * based on the bit rates and the cable compliance bytes.
291	 */
292	if ((id->base.sfp_ct_passive || id->base.sfp_ct_active) && br_nom) {
293		/* This may look odd, but some manufacturers use 12000MBd */
294		if (br_min <= 12000 && br_max >= 10300)
295			phylink_set(modes, 10000baseCR_Full);
296		if (br_min <= 3200 && br_max >= 3100)
297			phylink_set(modes, 2500baseX_Full);
298		if (br_min <= 1300 && br_max >= 1200)
299			phylink_set(modes, 1000baseX_Full);
300	}
301	if (id->base.sfp_ct_passive) {
302		if (id->base.passive.sff8431_app_e)
303			phylink_set(modes, 10000baseCR_Full);
304	}
305	if (id->base.sfp_ct_active) {
306		if (id->base.active.sff8431_app_e ||
307		    id->base.active.sff8431_lim) {
308			phylink_set(modes, 10000baseCR_Full);
309		}
310	}
311
312	switch (id->base.extended_cc) {
313	case SFF8024_ECC_UNSPEC:
314		break;
315	case SFF8024_ECC_100GBASE_SR4_25GBASE_SR:
316		phylink_set(modes, 100000baseSR4_Full);
317		phylink_set(modes, 25000baseSR_Full);
318		break;
319	case SFF8024_ECC_100GBASE_LR4_25GBASE_LR:
320	case SFF8024_ECC_100GBASE_ER4_25GBASE_ER:
321		phylink_set(modes, 100000baseLR4_ER4_Full);
322		break;
323	case SFF8024_ECC_100GBASE_CR4:
324		phylink_set(modes, 100000baseCR4_Full);
325		fallthrough;
326	case SFF8024_ECC_25GBASE_CR_S:
327	case SFF8024_ECC_25GBASE_CR_N:
328		phylink_set(modes, 25000baseCR_Full);
329		break;
330	case SFF8024_ECC_10GBASE_T_SFI:
331	case SFF8024_ECC_10GBASE_T_SR:
332		phylink_set(modes, 10000baseT_Full);
333		break;
334	case SFF8024_ECC_5GBASE_T:
335		phylink_set(modes, 5000baseT_Full);
336		break;
337	case SFF8024_ECC_2_5GBASE_T:
338		phylink_set(modes, 2500baseT_Full);
339		break;
340	default:
341		dev_warn(bus->sfp_dev,
342			 "Unknown/unsupported extended compliance code: 0x%02x\n",
343			 id->base.extended_cc);
344		break;
345	}
346
347	/* For fibre channel SFP, derive possible BaseX modes */
348	if (id->base.fc_speed_100 ||
349	    id->base.fc_speed_200 ||
350	    id->base.fc_speed_400) {
351		if (id->base.br_nominal >= 31)
352			phylink_set(modes, 2500baseX_Full);
353		if (id->base.br_nominal >= 12)
354			phylink_set(modes, 1000baseX_Full);
355	}
356
357	/* If we haven't discovered any modes that this module supports, try
358	 * the bitrate to determine supported modes. Some BiDi modules (eg,
359	 * 1310nm/1550nm) are not 1000BASE-BX compliant due to the differing
360	 * wavelengths, so do not set any transceiver bits.
361	 */
362	if (bitmap_empty(modes, __ETHTOOL_LINK_MODE_MASK_NBITS)) {
363		/* If the bit rate allows 1000baseX */
364		if (br_nom && br_min <= 1300 && br_max >= 1200)
365			phylink_set(modes, 1000baseX_Full);
366	}
367
368	if (bus->sfp_quirk)
369		bus->sfp_quirk->modes(id, modes);
370
371	bitmap_or(support, support, modes, __ETHTOOL_LINK_MODE_MASK_NBITS);
372
373	phylink_set(support, Autoneg);
374	phylink_set(support, Pause);
375	phylink_set(support, Asym_Pause);
376}
377EXPORT_SYMBOL_GPL(sfp_parse_support);
378
379/**
380 * sfp_select_interface() - Select appropriate phy_interface_t mode
381 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
382 * @link_modes: ethtool link modes mask
383 *
384 * Derive the phy_interface_t mode for the SFP module from the link
385 * modes mask.
386 */
387phy_interface_t sfp_select_interface(struct sfp_bus *bus,
388				     unsigned long *link_modes)
389{
390	if (phylink_test(link_modes, 10000baseCR_Full) ||
391	    phylink_test(link_modes, 10000baseSR_Full) ||
392	    phylink_test(link_modes, 10000baseLR_Full) ||
393	    phylink_test(link_modes, 10000baseLRM_Full) ||
394	    phylink_test(link_modes, 10000baseER_Full) ||
395	    phylink_test(link_modes, 10000baseT_Full))
396		return PHY_INTERFACE_MODE_10GBASER;
397
398	if (phylink_test(link_modes, 2500baseX_Full))
399		return PHY_INTERFACE_MODE_2500BASEX;
400
401	if (phylink_test(link_modes, 1000baseT_Half) ||
402	    phylink_test(link_modes, 1000baseT_Full))
403		return PHY_INTERFACE_MODE_SGMII;
404
405	if (phylink_test(link_modes, 1000baseX_Full))
406		return PHY_INTERFACE_MODE_1000BASEX;
407
408	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
409
410	return PHY_INTERFACE_MODE_NA;
411}
412EXPORT_SYMBOL_GPL(sfp_select_interface);
413
414static LIST_HEAD(sfp_buses);
415static DEFINE_MUTEX(sfp_mutex);
416
417static const struct sfp_upstream_ops *sfp_get_upstream_ops(struct sfp_bus *bus)
418{
419	return bus->registered ? bus->upstream_ops : NULL;
420}
421
422static struct sfp_bus *sfp_bus_get(struct fwnode_handle *fwnode)
423{
424	struct sfp_bus *sfp, *new, *found = NULL;
425
426	new = kzalloc(sizeof(*new), GFP_KERNEL);
427
428	mutex_lock(&sfp_mutex);
429
430	list_for_each_entry(sfp, &sfp_buses, node) {
431		if (sfp->fwnode == fwnode) {
432			kref_get(&sfp->kref);
433			found = sfp;
434			break;
435		}
436	}
437
438	if (!found && new) {
439		kref_init(&new->kref);
440		new->fwnode = fwnode;
441		list_add(&new->node, &sfp_buses);
442		found = new;
443		new = NULL;
444	}
445
446	mutex_unlock(&sfp_mutex);
447
448	kfree(new);
449
450	return found;
451}
452
453static void sfp_bus_release(struct kref *kref)
454{
455	struct sfp_bus *bus = container_of(kref, struct sfp_bus, kref);
456
457	list_del(&bus->node);
458	mutex_unlock(&sfp_mutex);
459	kfree(bus);
460}
461
462/**
463 * sfp_bus_put() - put a reference on the &struct sfp_bus
464 * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
465 *
466 * Put a reference on the &struct sfp_bus and free the underlying structure
467 * if this was the last reference.
468 */
469void sfp_bus_put(struct sfp_bus *bus)
470{
471	if (bus)
472		kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
473}
474EXPORT_SYMBOL_GPL(sfp_bus_put);
475
476static int sfp_register_bus(struct sfp_bus *bus)
477{
478	const struct sfp_upstream_ops *ops = bus->upstream_ops;
479	int ret;
480
481	if (ops) {
482		if (ops->link_down)
483			ops->link_down(bus->upstream);
484		if (ops->connect_phy && bus->phydev) {
485			ret = ops->connect_phy(bus->upstream, bus->phydev);
486			if (ret)
487				return ret;
488		}
489	}
490	bus->registered = true;
491	bus->socket_ops->attach(bus->sfp);
492	if (bus->started)
493		bus->socket_ops->start(bus->sfp);
494	bus->upstream_ops->attach(bus->upstream, bus);
495	return 0;
496}
497
498static void sfp_unregister_bus(struct sfp_bus *bus)
499{
500	const struct sfp_upstream_ops *ops = bus->upstream_ops;
501
502	if (bus->registered) {
503		bus->upstream_ops->detach(bus->upstream, bus);
504		if (bus->started)
505			bus->socket_ops->stop(bus->sfp);
506		bus->socket_ops->detach(bus->sfp);
507		if (bus->phydev && ops && ops->disconnect_phy)
508			ops->disconnect_phy(bus->upstream);
509	}
510	bus->registered = false;
511}
512
513/**
514 * sfp_get_module_info() - Get the ethtool_modinfo for a SFP module
515 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
516 * @modinfo: a &struct ethtool_modinfo
517 *
518 * Fill in the type and eeprom_len parameters in @modinfo for a module on
519 * the sfp bus specified by @bus.
520 *
521 * Returns 0 on success or a negative errno number.
522 */
523int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo)
524{
525	return bus->socket_ops->module_info(bus->sfp, modinfo);
526}
527EXPORT_SYMBOL_GPL(sfp_get_module_info);
528
529/**
530 * sfp_get_module_eeprom() - Read the SFP module EEPROM
531 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
532 * @ee: a &struct ethtool_eeprom
533 * @data: buffer to contain the EEPROM data (must be at least @ee->len bytes)
534 *
535 * Read the EEPROM as specified by the supplied @ee. See the documentation
536 * for &struct ethtool_eeprom for the region to be read.
537 *
538 * Returns 0 on success or a negative errno number.
539 */
540int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
541			  u8 *data)
542{
543	return bus->socket_ops->module_eeprom(bus->sfp, ee, data);
544}
545EXPORT_SYMBOL_GPL(sfp_get_module_eeprom);
546
547/**
548 * sfp_upstream_start() - Inform the SFP that the network device is up
549 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
550 *
551 * Inform the SFP socket that the network device is now up, so that the
552 * module can be enabled by allowing TX_DISABLE to be deasserted. This
553 * should be called from the network device driver's &struct net_device_ops
554 * ndo_open() method.
555 */
556void sfp_upstream_start(struct sfp_bus *bus)
557{
558	if (bus->registered)
559		bus->socket_ops->start(bus->sfp);
560	bus->started = true;
561}
562EXPORT_SYMBOL_GPL(sfp_upstream_start);
563
564/**
565 * sfp_upstream_stop() - Inform the SFP that the network device is down
566 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
567 *
568 * Inform the SFP socket that the network device is now up, so that the
569 * module can be disabled by asserting TX_DISABLE, disabling the laser
570 * in optical modules. This should be called from the network device
571 * driver's &struct net_device_ops ndo_stop() method.
572 */
573void sfp_upstream_stop(struct sfp_bus *bus)
574{
575	if (bus->registered)
576		bus->socket_ops->stop(bus->sfp);
577	bus->started = false;
578}
579EXPORT_SYMBOL_GPL(sfp_upstream_stop);
580
581static void sfp_upstream_clear(struct sfp_bus *bus)
582{
583	bus->upstream_ops = NULL;
584	bus->upstream = NULL;
585}
586
587/**
588 * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
589 * @fwnode: firmware node for the parent device (MAC or PHY)
590 *
591 * Parse the parent device's firmware node for a SFP bus, and locate
592 * the sfp_bus structure, incrementing its reference count.  This must
593 * be put via sfp_bus_put() when done.
594 *
595 * Returns:
596 * 	    - on success, a pointer to the sfp_bus structure,
597 *	    - %NULL if no SFP is specified,
598 * 	    - on failure, an error pointer value:
599 *
600 * 	      - corresponding to the errors detailed for
601 * 	        fwnode_property_get_reference_args().
602 * 	      - %-ENOMEM if we failed to allocate the bus.
603 *	      - an error from the upstream's connect_phy() method.
604 */
605struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
606{
607	struct fwnode_reference_args ref;
608	struct sfp_bus *bus;
609	int ret;
610
611	ret = fwnode_property_get_reference_args(fwnode, "sfp", NULL,
612						 0, 0, &ref);
613	if (ret == -ENOENT)
614		return NULL;
615	else if (ret < 0)
616		return ERR_PTR(ret);
617
618	if (!fwnode_device_is_available(ref.fwnode)) {
619		fwnode_handle_put(ref.fwnode);
620		return NULL;
621	}
622
623	bus = sfp_bus_get(ref.fwnode);
624	fwnode_handle_put(ref.fwnode);
625	if (!bus)
626		return ERR_PTR(-ENOMEM);
627
628	return bus;
629}
630EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
631
632/**
633 * sfp_bus_add_upstream() - parse and register the neighbouring device
634 * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
635 * @upstream: the upstream private data
636 * @ops: the upstream's &struct sfp_upstream_ops
637 *
638 * Add upstream driver for the SFP bus, and if the bus is complete, register
639 * the SFP bus using sfp_register_upstream().  This takes a reference on the
640 * bus, so it is safe to put the bus after this call.
641 *
642 * Returns:
643 * 	    - on success, a pointer to the sfp_bus structure,
644 *	    - %NULL if no SFP is specified,
645 * 	    - on failure, an error pointer value:
646 *
647 * 	      - corresponding to the errors detailed for
648 * 	        fwnode_property_get_reference_args().
649 * 	      - %-ENOMEM if we failed to allocate the bus.
650 *	      - an error from the upstream's connect_phy() method.
651 */
652int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
653			 const struct sfp_upstream_ops *ops)
654{
655	int ret;
656
657	/* If no bus, return success */
658	if (!bus)
659		return 0;
660
661	rtnl_lock();
662	kref_get(&bus->kref);
663	bus->upstream_ops = ops;
664	bus->upstream = upstream;
665
666	if (bus->sfp) {
667		ret = sfp_register_bus(bus);
668		if (ret)
669			sfp_upstream_clear(bus);
670	} else {
671		ret = 0;
672	}
673	rtnl_unlock();
674
675	if (ret)
676		sfp_bus_put(bus);
677
678	return ret;
679}
680EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
681
682/**
683 * sfp_bus_del_upstream() - Delete a sfp bus
684 * @bus: a pointer to the &struct sfp_bus structure for the sfp module
685 *
686 * Delete a previously registered upstream connection for the SFP
687 * module. @bus should have been added by sfp_bus_add_upstream().
688 */
689void sfp_bus_del_upstream(struct sfp_bus *bus)
690{
691	if (bus) {
692		rtnl_lock();
693		if (bus->sfp)
694			sfp_unregister_bus(bus);
695		sfp_upstream_clear(bus);
696		rtnl_unlock();
697
698		sfp_bus_put(bus);
699	}
700}
701EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
702
703/* Socket driver entry points */
704int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
705{
706	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
707	int ret = 0;
708
709	if (ops && ops->connect_phy)
710		ret = ops->connect_phy(bus->upstream, phydev);
711
712	if (ret == 0)
713		bus->phydev = phydev;
714
715	return ret;
716}
717EXPORT_SYMBOL_GPL(sfp_add_phy);
718
719void sfp_remove_phy(struct sfp_bus *bus)
720{
721	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
722
723	if (ops && ops->disconnect_phy)
724		ops->disconnect_phy(bus->upstream);
725	bus->phydev = NULL;
726}
727EXPORT_SYMBOL_GPL(sfp_remove_phy);
728
729void sfp_link_up(struct sfp_bus *bus)
730{
731	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
732
733	if (ops && ops->link_up)
734		ops->link_up(bus->upstream);
735}
736EXPORT_SYMBOL_GPL(sfp_link_up);
737
738void sfp_link_down(struct sfp_bus *bus)
739{
740	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
741
742	if (ops && ops->link_down)
743		ops->link_down(bus->upstream);
744}
745EXPORT_SYMBOL_GPL(sfp_link_down);
746
747int sfp_module_insert(struct sfp_bus *bus, const struct sfp_eeprom_id *id)
748{
749	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
750	int ret = 0;
751
752	bus->sfp_quirk = sfp_lookup_quirk(id);
753
754	if (ops && ops->module_insert)
755		ret = ops->module_insert(bus->upstream, id);
756
757	return ret;
758}
759EXPORT_SYMBOL_GPL(sfp_module_insert);
760
761void sfp_module_remove(struct sfp_bus *bus)
762{
763	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
764
765	if (ops && ops->module_remove)
766		ops->module_remove(bus->upstream);
767
768	bus->sfp_quirk = NULL;
769}
770EXPORT_SYMBOL_GPL(sfp_module_remove);
771
772int sfp_module_start(struct sfp_bus *bus)
773{
774	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
775	int ret = 0;
776
777	if (ops && ops->module_start)
778		ret = ops->module_start(bus->upstream);
779
780	return ret;
781}
782EXPORT_SYMBOL_GPL(sfp_module_start);
783
784void sfp_module_stop(struct sfp_bus *bus)
785{
786	const struct sfp_upstream_ops *ops = sfp_get_upstream_ops(bus);
787
788	if (ops && ops->module_stop)
789		ops->module_stop(bus->upstream);
790}
791EXPORT_SYMBOL_GPL(sfp_module_stop);
792
793static void sfp_socket_clear(struct sfp_bus *bus)
794{
795	bus->sfp_dev = NULL;
796	bus->sfp = NULL;
797	bus->socket_ops = NULL;
798}
799
800struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
801				    const struct sfp_socket_ops *ops)
802{
803	struct sfp_bus *bus = sfp_bus_get(dev->fwnode);
804	int ret = 0;
805
806	if (bus) {
807		rtnl_lock();
808		bus->sfp_dev = dev;
809		bus->sfp = sfp;
810		bus->socket_ops = ops;
811
812		if (bus->upstream_ops) {
813			ret = sfp_register_bus(bus);
814			if (ret)
815				sfp_socket_clear(bus);
816		}
817		rtnl_unlock();
818	}
819
820	if (ret) {
821		sfp_bus_put(bus);
822		bus = NULL;
823	}
824
825	return bus;
826}
827EXPORT_SYMBOL_GPL(sfp_register_socket);
828
829void sfp_unregister_socket(struct sfp_bus *bus)
830{
831	rtnl_lock();
832	if (bus->upstream_ops)
833		sfp_unregister_bus(bus);
834	sfp_socket_clear(bus);
835	rtnl_unlock();
836
837	sfp_bus_put(bus);
838}
839EXPORT_SYMBOL_GPL(sfp_unregister_socket);
840