xref: /openbmc/linux/drivers/net/mdio.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * mdio.c: Generic support for MDIO-compatible transceivers
4  * Copyright 2006-2009 Solarflare Communications Inc.
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/capability.h>
9 #include <linux/errno.h>
10 #include <linux/ethtool.h>
11 #include <linux/mdio.h>
12 #include <linux/module.h>
13 
14 MODULE_DESCRIPTION("Generic support for MDIO-compatible transceivers");
15 MODULE_AUTHOR("Copyright 2006-2009 Solarflare Communications Inc.");
16 MODULE_LICENSE("GPL");
17 
18 /**
19  * mdio45_probe - probe for an MDIO (clause 45) device
20  * @mdio: MDIO interface
21  * @prtad: Expected PHY address
22  *
23  * This sets @prtad and @mmds in the MDIO interface if successful.
24  * Returns 0 on success, negative on error.
25  */
26 int mdio45_probe(struct mdio_if_info *mdio, int prtad)
27 {
28 	int mmd, stat2, devs1, devs2;
29 
30 	/* Assume PHY must have at least one of PMA/PMD, WIS, PCS, PHY
31 	 * XS or DTE XS; give up if none is present. */
32 	for (mmd = 1; mmd <= 5; mmd++) {
33 		/* Is this MMD present? */
34 		stat2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_STAT2);
35 		if (stat2 < 0 ||
36 		    (stat2 & MDIO_STAT2_DEVPRST) != MDIO_STAT2_DEVPRST_VAL)
37 			continue;
38 
39 		/* It should tell us about all the other MMDs */
40 		devs1 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS1);
41 		devs2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS2);
42 		if (devs1 < 0 || devs2 < 0)
43 			continue;
44 
45 		mdio->prtad = prtad;
46 		mdio->mmds = devs1 | (devs2 << 16);
47 		return 0;
48 	}
49 
50 	return -ENODEV;
51 }
52 EXPORT_SYMBOL(mdio45_probe);
53 
54 /**
55  * mdio_set_flag - set or clear flag in an MDIO register
56  * @mdio: MDIO interface
57  * @prtad: PHY address
58  * @devad: MMD address
59  * @addr: Register address
60  * @mask: Mask for flag (single bit set)
61  * @sense: New value of flag
62  *
63  * This debounces changes: it does not write the register if the flag
64  * already has the proper value.  Returns 0 on success, negative on error.
65  */
66 int mdio_set_flag(const struct mdio_if_info *mdio,
67 		  int prtad, int devad, u16 addr, int mask,
68 		  bool sense)
69 {
70 	int old_val = mdio->mdio_read(mdio->dev, prtad, devad, addr);
71 	int new_val;
72 
73 	if (old_val < 0)
74 		return old_val;
75 	if (sense)
76 		new_val = old_val | mask;
77 	else
78 		new_val = old_val & ~mask;
79 	if (old_val == new_val)
80 		return 0;
81 	return mdio->mdio_write(mdio->dev, prtad, devad, addr, new_val);
82 }
83 EXPORT_SYMBOL(mdio_set_flag);
84 
85 /**
86  * mdio45_links_ok - is link status up/OK
87  * @mdio: MDIO interface
88  * @mmd_mask: Mask for MMDs to check
89  *
90  * Returns 1 if the PHY reports link status up/OK, 0 otherwise.
91  * @mmd_mask is normally @mdio->mmds, but if loopback is enabled
92  * the MMDs being bypassed should be excluded from the mask.
93  */
94 int mdio45_links_ok(const struct mdio_if_info *mdio, u32 mmd_mask)
95 {
96 	int devad, reg;
97 
98 	if (!mmd_mask) {
99 		/* Use absence of XGMII faults in lieu of link state */
100 		reg = mdio->mdio_read(mdio->dev, mdio->prtad,
101 				      MDIO_MMD_PHYXS, MDIO_STAT2);
102 		return reg >= 0 && !(reg & MDIO_STAT2_RXFAULT);
103 	}
104 
105 	for (devad = 0; mmd_mask; devad++) {
106 		if (mmd_mask & (1 << devad)) {
107 			mmd_mask &= ~(1 << devad);
108 
109 			/* Reset the latched status and fault flags */
110 			mdio->mdio_read(mdio->dev, mdio->prtad,
111 					devad, MDIO_STAT1);
112 			if (devad == MDIO_MMD_PMAPMD || devad == MDIO_MMD_PCS ||
113 			    devad == MDIO_MMD_PHYXS || devad == MDIO_MMD_DTEXS)
114 				mdio->mdio_read(mdio->dev, mdio->prtad,
115 						devad, MDIO_STAT2);
116 
117 			/* Check the current status and fault flags */
118 			reg = mdio->mdio_read(mdio->dev, mdio->prtad,
119 					      devad, MDIO_STAT1);
120 			if (reg < 0 ||
121 			    (reg & (MDIO_STAT1_FAULT | MDIO_STAT1_LSTATUS)) !=
122 			    MDIO_STAT1_LSTATUS)
123 				return false;
124 		}
125 	}
126 
127 	return true;
128 }
129 EXPORT_SYMBOL(mdio45_links_ok);
130 
131 /**
132  * mdio45_nway_restart - restart auto-negotiation for this interface
133  * @mdio: MDIO interface
134  *
135  * Returns 0 on success, negative on error.
136  */
137 int mdio45_nway_restart(const struct mdio_if_info *mdio)
138 {
139 	if (!(mdio->mmds & MDIO_DEVS_AN))
140 		return -EOPNOTSUPP;
141 
142 	mdio_set_flag(mdio, mdio->prtad, MDIO_MMD_AN, MDIO_CTRL1,
143 		      MDIO_AN_CTRL1_RESTART, true);
144 	return 0;
145 }
146 EXPORT_SYMBOL(mdio45_nway_restart);
147 
148 static u32 mdio45_get_an(const struct mdio_if_info *mdio, u16 addr)
149 {
150 	u32 result = 0;
151 	int reg;
152 
153 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN, addr);
154 	if (reg & ADVERTISE_10HALF)
155 		result |= ADVERTISED_10baseT_Half;
156 	if (reg & ADVERTISE_10FULL)
157 		result |= ADVERTISED_10baseT_Full;
158 	if (reg & ADVERTISE_100HALF)
159 		result |= ADVERTISED_100baseT_Half;
160 	if (reg & ADVERTISE_100FULL)
161 		result |= ADVERTISED_100baseT_Full;
162 	if (reg & ADVERTISE_PAUSE_CAP)
163 		result |= ADVERTISED_Pause;
164 	if (reg & ADVERTISE_PAUSE_ASYM)
165 		result |= ADVERTISED_Asym_Pause;
166 	return result;
167 }
168 
169 /**
170  * mdio45_ethtool_gset_npage - get settings for ETHTOOL_GSET
171  * @mdio: MDIO interface
172  * @ecmd: Ethtool request structure
173  * @npage_adv: Modes currently advertised on next pages
174  * @npage_lpa: Modes advertised by link partner on next pages
175  *
176  * The @ecmd parameter is expected to have been cleared before calling
177  * mdio45_ethtool_gset_npage().
178  *
179  * Since the CSRs for auto-negotiation using next pages are not fully
180  * standardised, this function does not attempt to decode them.  The
181  * caller must pass them in.
182  */
183 void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
184 			       struct ethtool_cmd *ecmd,
185 			       u32 npage_adv, u32 npage_lpa)
186 {
187 	int reg;
188 	u32 speed;
189 
190 	BUILD_BUG_ON(MDIO_SUPPORTS_C22 != ETH_MDIO_SUPPORTS_C22);
191 	BUILD_BUG_ON(MDIO_SUPPORTS_C45 != ETH_MDIO_SUPPORTS_C45);
192 
193 	ecmd->transceiver = XCVR_INTERNAL;
194 	ecmd->phy_address = mdio->prtad;
195 	ecmd->mdio_support =
196 		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);
197 
198 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
199 			      MDIO_CTRL2);
200 	switch (reg & MDIO_PMA_CTRL2_TYPE) {
201 	case MDIO_PMA_CTRL2_10GBT:
202 	case MDIO_PMA_CTRL2_1000BT:
203 	case MDIO_PMA_CTRL2_100BTX:
204 	case MDIO_PMA_CTRL2_10BT:
205 		ecmd->port = PORT_TP;
206 		ecmd->supported = SUPPORTED_TP;
207 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
208 				      MDIO_SPEED);
209 		if (reg & MDIO_SPEED_10G)
210 			ecmd->supported |= SUPPORTED_10000baseT_Full;
211 		if (reg & MDIO_PMA_SPEED_1000)
212 			ecmd->supported |= (SUPPORTED_1000baseT_Full |
213 					    SUPPORTED_1000baseT_Half);
214 		if (reg & MDIO_PMA_SPEED_100)
215 			ecmd->supported |= (SUPPORTED_100baseT_Full |
216 					    SUPPORTED_100baseT_Half);
217 		if (reg & MDIO_PMA_SPEED_10)
218 			ecmd->supported |= (SUPPORTED_10baseT_Full |
219 					    SUPPORTED_10baseT_Half);
220 		ecmd->advertising = ADVERTISED_TP;
221 		break;
222 
223 	case MDIO_PMA_CTRL2_10GBCX4:
224 		ecmd->port = PORT_OTHER;
225 		ecmd->supported = 0;
226 		ecmd->advertising = 0;
227 		break;
228 
229 	case MDIO_PMA_CTRL2_10GBKX4:
230 	case MDIO_PMA_CTRL2_10GBKR:
231 	case MDIO_PMA_CTRL2_1000BKX:
232 		ecmd->port = PORT_OTHER;
233 		ecmd->supported = SUPPORTED_Backplane;
234 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
235 				      MDIO_PMA_EXTABLE);
236 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
237 			ecmd->supported |= SUPPORTED_10000baseKX4_Full;
238 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
239 			ecmd->supported |= SUPPORTED_10000baseKR_Full;
240 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
241 			ecmd->supported |= SUPPORTED_1000baseKX_Full;
242 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
243 				      MDIO_PMA_10GBR_FECABLE);
244 		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
245 			ecmd->supported |= SUPPORTED_10000baseR_FEC;
246 		ecmd->advertising = ADVERTISED_Backplane;
247 		break;
248 
249 	/* All the other defined modes are flavours of optical */
250 	default:
251 		ecmd->port = PORT_FIBRE;
252 		ecmd->supported = SUPPORTED_FIBRE;
253 		ecmd->advertising = ADVERTISED_FIBRE;
254 		break;
255 	}
256 
257 	if (mdio->mmds & MDIO_DEVS_AN) {
258 		ecmd->supported |= SUPPORTED_Autoneg;
259 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
260 				      MDIO_CTRL1);
261 		if (reg & MDIO_AN_CTRL1_ENABLE) {
262 			ecmd->autoneg = AUTONEG_ENABLE;
263 			ecmd->advertising |=
264 				ADVERTISED_Autoneg |
265 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
266 				npage_adv;
267 		} else {
268 			ecmd->autoneg = AUTONEG_DISABLE;
269 		}
270 	} else {
271 		ecmd->autoneg = AUTONEG_DISABLE;
272 	}
273 
274 	if (ecmd->autoneg) {
275 		u32 modes = 0;
276 		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
277 					      MDIO_MMD_AN, MDIO_STAT1);
278 
279 		/* If AN is complete and successful, report best common
280 		 * mode, otherwise report best advertised mode. */
281 		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
282 			ecmd->lp_advertising =
283 				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
284 			if (an_stat & MDIO_AN_STAT1_LPABLE)
285 				ecmd->lp_advertising |= ADVERTISED_Autoneg;
286 			modes = ecmd->advertising & ecmd->lp_advertising;
287 		}
288 		if ((modes & ~ADVERTISED_Autoneg) == 0)
289 			modes = ecmd->advertising;
290 
291 		if (modes & (ADVERTISED_10000baseT_Full |
292 			     ADVERTISED_10000baseKX4_Full |
293 			     ADVERTISED_10000baseKR_Full)) {
294 			speed = SPEED_10000;
295 			ecmd->duplex = DUPLEX_FULL;
296 		} else if (modes & (ADVERTISED_1000baseT_Full |
297 				    ADVERTISED_1000baseT_Half |
298 				    ADVERTISED_1000baseKX_Full)) {
299 			speed = SPEED_1000;
300 			ecmd->duplex = !(modes & ADVERTISED_1000baseT_Half);
301 		} else if (modes & (ADVERTISED_100baseT_Full |
302 				    ADVERTISED_100baseT_Half)) {
303 			speed = SPEED_100;
304 			ecmd->duplex = !!(modes & ADVERTISED_100baseT_Full);
305 		} else {
306 			speed = SPEED_10;
307 			ecmd->duplex = !!(modes & ADVERTISED_10baseT_Full);
308 		}
309 	} else {
310 		/* Report forced settings */
311 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
312 				      MDIO_CTRL1);
313 		speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1)
314 			 * ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));
315 		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||
316 				speed == SPEED_10000);
317 	}
318 
319 	ethtool_cmd_speed_set(ecmd, speed);
320 
321 	/* 10GBASE-T MDI/MDI-X */
322 	if (ecmd->port == PORT_TP
323 	    && (ethtool_cmd_speed(ecmd) == SPEED_10000)) {
324 		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
325 					MDIO_PMA_10GBT_SWAPPOL)) {
326 		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
327 			ecmd->eth_tp_mdix = ETH_TP_MDI;
328 			break;
329 		case 0:
330 			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
331 			break;
332 		default:
333 			/* It's complicated... */
334 			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
335 			break;
336 		}
337 	}
338 }
339 EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
340 
341 /**
342  * mdio45_ethtool_ksettings_get_npage - get settings for ETHTOOL_GLINKSETTINGS
343  * @mdio: MDIO interface
344  * @cmd: Ethtool request structure
345  * @npage_adv: Modes currently advertised on next pages
346  * @npage_lpa: Modes advertised by link partner on next pages
347  *
348  * The @cmd parameter is expected to have been cleared before calling
349  * mdio45_ethtool_ksettings_get_npage().
350  *
351  * Since the CSRs for auto-negotiation using next pages are not fully
352  * standardised, this function does not attempt to decode them.  The
353  * caller must pass them in.
354  */
355 void mdio45_ethtool_ksettings_get_npage(const struct mdio_if_info *mdio,
356 					struct ethtool_link_ksettings *cmd,
357 					u32 npage_adv, u32 npage_lpa)
358 {
359 	int reg;
360 	u32 speed, supported = 0, advertising = 0, lp_advertising = 0;
361 
362 	BUILD_BUG_ON(MDIO_SUPPORTS_C22 != ETH_MDIO_SUPPORTS_C22);
363 	BUILD_BUG_ON(MDIO_SUPPORTS_C45 != ETH_MDIO_SUPPORTS_C45);
364 
365 	cmd->base.phy_address = mdio->prtad;
366 	cmd->base.mdio_support =
367 		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);
368 
369 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
370 			      MDIO_CTRL2);
371 	switch (reg & MDIO_PMA_CTRL2_TYPE) {
372 	case MDIO_PMA_CTRL2_10GBT:
373 	case MDIO_PMA_CTRL2_1000BT:
374 	case MDIO_PMA_CTRL2_100BTX:
375 	case MDIO_PMA_CTRL2_10BT:
376 		cmd->base.port = PORT_TP;
377 		supported = SUPPORTED_TP;
378 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
379 				      MDIO_SPEED);
380 		if (reg & MDIO_SPEED_10G)
381 			supported |= SUPPORTED_10000baseT_Full;
382 		if (reg & MDIO_PMA_SPEED_1000)
383 			supported |= (SUPPORTED_1000baseT_Full |
384 					    SUPPORTED_1000baseT_Half);
385 		if (reg & MDIO_PMA_SPEED_100)
386 			supported |= (SUPPORTED_100baseT_Full |
387 					    SUPPORTED_100baseT_Half);
388 		if (reg & MDIO_PMA_SPEED_10)
389 			supported |= (SUPPORTED_10baseT_Full |
390 					    SUPPORTED_10baseT_Half);
391 		advertising = ADVERTISED_TP;
392 		break;
393 
394 	case MDIO_PMA_CTRL2_10GBCX4:
395 		cmd->base.port = PORT_OTHER;
396 		supported = 0;
397 		advertising = 0;
398 		break;
399 
400 	case MDIO_PMA_CTRL2_10GBKX4:
401 	case MDIO_PMA_CTRL2_10GBKR:
402 	case MDIO_PMA_CTRL2_1000BKX:
403 		cmd->base.port = PORT_OTHER;
404 		supported = SUPPORTED_Backplane;
405 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
406 				      MDIO_PMA_EXTABLE);
407 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
408 			supported |= SUPPORTED_10000baseKX4_Full;
409 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
410 			supported |= SUPPORTED_10000baseKR_Full;
411 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
412 			supported |= SUPPORTED_1000baseKX_Full;
413 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
414 				      MDIO_PMA_10GBR_FECABLE);
415 		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
416 			supported |= SUPPORTED_10000baseR_FEC;
417 		advertising = ADVERTISED_Backplane;
418 		break;
419 
420 	/* All the other defined modes are flavours of optical */
421 	default:
422 		cmd->base.port = PORT_FIBRE;
423 		supported = SUPPORTED_FIBRE;
424 		advertising = ADVERTISED_FIBRE;
425 		break;
426 	}
427 
428 	if (mdio->mmds & MDIO_DEVS_AN) {
429 		supported |= SUPPORTED_Autoneg;
430 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
431 				      MDIO_CTRL1);
432 		if (reg & MDIO_AN_CTRL1_ENABLE) {
433 			cmd->base.autoneg = AUTONEG_ENABLE;
434 			advertising |=
435 				ADVERTISED_Autoneg |
436 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
437 				npage_adv;
438 		} else {
439 			cmd->base.autoneg = AUTONEG_DISABLE;
440 		}
441 	} else {
442 		cmd->base.autoneg = AUTONEG_DISABLE;
443 	}
444 
445 	if (cmd->base.autoneg) {
446 		u32 modes = 0;
447 		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
448 					      MDIO_MMD_AN, MDIO_STAT1);
449 
450 		/* If AN is complete and successful, report best common
451 		 * mode, otherwise report best advertised mode.
452 		 */
453 		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
454 			lp_advertising =
455 				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
456 			if (an_stat & MDIO_AN_STAT1_LPABLE)
457 				lp_advertising |= ADVERTISED_Autoneg;
458 			modes = advertising & lp_advertising;
459 		}
460 		if ((modes & ~ADVERTISED_Autoneg) == 0)
461 			modes = advertising;
462 
463 		if (modes & (ADVERTISED_10000baseT_Full |
464 			     ADVERTISED_10000baseKX4_Full |
465 			     ADVERTISED_10000baseKR_Full)) {
466 			speed = SPEED_10000;
467 			cmd->base.duplex = DUPLEX_FULL;
468 		} else if (modes & (ADVERTISED_1000baseT_Full |
469 				    ADVERTISED_1000baseT_Half |
470 				    ADVERTISED_1000baseKX_Full)) {
471 			speed = SPEED_1000;
472 			cmd->base.duplex = !(modes & ADVERTISED_1000baseT_Half);
473 		} else if (modes & (ADVERTISED_100baseT_Full |
474 				    ADVERTISED_100baseT_Half)) {
475 			speed = SPEED_100;
476 			cmd->base.duplex = !!(modes & ADVERTISED_100baseT_Full);
477 		} else {
478 			speed = SPEED_10;
479 			cmd->base.duplex = !!(modes & ADVERTISED_10baseT_Full);
480 		}
481 	} else {
482 		/* Report forced settings */
483 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
484 				      MDIO_CTRL1);
485 		speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1)
486 			 * ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));
487 		cmd->base.duplex = (reg & MDIO_CTRL1_FULLDPLX ||
488 				    speed == SPEED_10000);
489 	}
490 
491 	cmd->base.speed = speed;
492 
493 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
494 						supported);
495 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
496 						advertising);
497 	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.lp_advertising,
498 						lp_advertising);
499 
500 	/* 10GBASE-T MDI/MDI-X */
501 	if (cmd->base.port == PORT_TP && (cmd->base.speed == SPEED_10000)) {
502 		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
503 					MDIO_PMA_10GBT_SWAPPOL)) {
504 		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
505 			cmd->base.eth_tp_mdix = ETH_TP_MDI;
506 			break;
507 		case 0:
508 			cmd->base.eth_tp_mdix = ETH_TP_MDI_X;
509 			break;
510 		default:
511 			/* It's complicated... */
512 			cmd->base.eth_tp_mdix = ETH_TP_MDI_INVALID;
513 			break;
514 		}
515 	}
516 }
517 EXPORT_SYMBOL(mdio45_ethtool_ksettings_get_npage);
518 
519 /**
520  * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
521  * @mdio: MDIO interface
522  * @mii_data: MII ioctl data structure
523  * @cmd: MII ioctl command
524  *
525  * Returns 0 on success, negative on error.
526  */
527 int mdio_mii_ioctl(const struct mdio_if_info *mdio,
528 		   struct mii_ioctl_data *mii_data, int cmd)
529 {
530 	int prtad, devad;
531 	u16 addr = mii_data->reg_num;
532 
533 	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
534 	switch (cmd) {
535 	case SIOCGMIIPHY:
536 		if (mdio->prtad == MDIO_PRTAD_NONE)
537 			return -EOPNOTSUPP;
538 		mii_data->phy_id = mdio->prtad;
539 		cmd = SIOCGMIIREG;
540 		break;
541 	case SIOCGMIIREG:
542 	case SIOCSMIIREG:
543 		break;
544 	default:
545 		return -EOPNOTSUPP;
546 	}
547 
548 	/* Validate/convert phy_id */
549 	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
550 	    mdio_phy_id_is_c45(mii_data->phy_id)) {
551 		prtad = mdio_phy_id_prtad(mii_data->phy_id);
552 		devad = mdio_phy_id_devad(mii_data->phy_id);
553 	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
554 		   mii_data->phy_id < 0x20) {
555 		prtad = mii_data->phy_id;
556 		devad = MDIO_DEVAD_NONE;
557 		addr &= 0x1f;
558 	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
559 		   mdio->prtad != MDIO_PRTAD_NONE &&
560 		   mii_data->phy_id == mdio->prtad) {
561 		/* Remap commonly-used MII registers. */
562 		prtad = mdio->prtad;
563 		switch (addr) {
564 		case MII_BMCR:
565 		case MII_BMSR:
566 		case MII_PHYSID1:
567 		case MII_PHYSID2:
568 			devad = __ffs(mdio->mmds);
569 			break;
570 		case MII_ADVERTISE:
571 		case MII_LPA:
572 			if (!(mdio->mmds & MDIO_DEVS_AN))
573 				return -EINVAL;
574 			devad = MDIO_MMD_AN;
575 			if (addr == MII_ADVERTISE)
576 				addr = MDIO_AN_ADVERTISE;
577 			else
578 				addr = MDIO_AN_LPA;
579 			break;
580 		default:
581 			return -EINVAL;
582 		}
583 	} else {
584 		return -EINVAL;
585 	}
586 
587 	if (cmd == SIOCGMIIREG) {
588 		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
589 		if (rc < 0)
590 			return rc;
591 		mii_data->val_out = rc;
592 		return 0;
593 	} else {
594 		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
595 					mii_data->val_in);
596 	}
597 }
598 EXPORT_SYMBOL(mdio_mii_ioctl);
599