Merge remote-tracking branch 'regulator/for-5.13' into regulator-linus
[platform/kernel/linux-rpi.git] / drivers / net / mdio.c
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);