xref: /openbmc/linux/drivers/net/mdio.c (revision e8e0929d)
1 /*
2  * mdio.c: Generic support for MDIO-compatible transceivers
3  * Copyright 2006-2009 Solarflare Communications Inc.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published
7  * by the Free Software Foundation, incorporated herein by reference.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/capability.h>
12 #include <linux/errno.h>
13 #include <linux/ethtool.h>
14 #include <linux/mdio.h>
15 #include <linux/module.h>
16 
17 MODULE_DESCRIPTION("Generic support for MDIO-compatible transceivers");
18 MODULE_AUTHOR("Copyright 2006-2009 Solarflare Communications Inc.");
19 MODULE_LICENSE("GPL");
20 
21 /**
22  * mdio45_probe - probe for an MDIO (clause 45) device
23  * @mdio: MDIO interface
24  * @prtad: Expected PHY address
25  *
26  * This sets @prtad and @mmds in the MDIO interface if successful.
27  * Returns 0 on success, negative on error.
28  */
29 int mdio45_probe(struct mdio_if_info *mdio, int prtad)
30 {
31 	int mmd, stat2, devs1, devs2;
32 
33 	/* Assume PHY must have at least one of PMA/PMD, WIS, PCS, PHY
34 	 * XS or DTE XS; give up if none is present. */
35 	for (mmd = 1; mmd <= 5; mmd++) {
36 		/* Is this MMD present? */
37 		stat2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_STAT2);
38 		if (stat2 < 0 ||
39 		    (stat2 & MDIO_STAT2_DEVPRST) != MDIO_STAT2_DEVPRST_VAL)
40 			continue;
41 
42 		/* It should tell us about all the other MMDs */
43 		devs1 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS1);
44 		devs2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS2);
45 		if (devs1 < 0 || devs2 < 0)
46 			continue;
47 
48 		mdio->prtad = prtad;
49 		mdio->mmds = devs1 | (devs2 << 16);
50 		return 0;
51 	}
52 
53 	return -ENODEV;
54 }
55 EXPORT_SYMBOL(mdio45_probe);
56 
57 /**
58  * mdio_set_flag - set or clear flag in an MDIO register
59  * @mdio: MDIO interface
60  * @prtad: PHY address
61  * @devad: MMD address
62  * @addr: Register address
63  * @mask: Mask for flag (single bit set)
64  * @sense: New value of flag
65  *
66  * This debounces changes: it does not write the register if the flag
67  * already has the proper value.  Returns 0 on success, negative on error.
68  */
69 int mdio_set_flag(const struct mdio_if_info *mdio,
70 		  int prtad, int devad, u16 addr, int mask,
71 		  bool sense)
72 {
73 	int old_val = mdio->mdio_read(mdio->dev, prtad, devad, addr);
74 	int new_val;
75 
76 	if (old_val < 0)
77 		return old_val;
78 	if (sense)
79 		new_val = old_val | mask;
80 	else
81 		new_val = old_val & ~mask;
82 	if (old_val == new_val)
83 		return 0;
84 	return mdio->mdio_write(mdio->dev, prtad, devad, addr, new_val);
85 }
86 EXPORT_SYMBOL(mdio_set_flag);
87 
88 /**
89  * mdio_link_ok - is link status up/OK
90  * @mdio: MDIO interface
91  * @mmd_mask: Mask for MMDs to check
92  *
93  * Returns 1 if the PHY reports link status up/OK, 0 otherwise.
94  * @mmd_mask is normally @mdio->mmds, but if loopback is enabled
95  * the MMDs being bypassed should be excluded from the mask.
96  */
97 int mdio45_links_ok(const struct mdio_if_info *mdio, u32 mmd_mask)
98 {
99 	int devad, reg;
100 
101 	if (!mmd_mask) {
102 		/* Use absence of XGMII faults in lieu of link state */
103 		reg = mdio->mdio_read(mdio->dev, mdio->prtad,
104 				      MDIO_MMD_PHYXS, MDIO_STAT2);
105 		return reg >= 0 && !(reg & MDIO_STAT2_RXFAULT);
106 	}
107 
108 	for (devad = 0; mmd_mask; devad++) {
109 		if (mmd_mask & (1 << devad)) {
110 			mmd_mask &= ~(1 << devad);
111 
112 			/* Reset the latched status and fault flags */
113 			mdio->mdio_read(mdio->dev, mdio->prtad,
114 					devad, MDIO_STAT1);
115 			if (devad == MDIO_MMD_PMAPMD || devad == MDIO_MMD_PCS ||
116 			    devad == MDIO_MMD_PHYXS || devad == MDIO_MMD_DTEXS)
117 				mdio->mdio_read(mdio->dev, mdio->prtad,
118 						devad, MDIO_STAT2);
119 
120 			/* Check the current status and fault flags */
121 			reg = mdio->mdio_read(mdio->dev, mdio->prtad,
122 					      devad, MDIO_STAT1);
123 			if (reg < 0 ||
124 			    (reg & (MDIO_STAT1_FAULT | MDIO_STAT1_LSTATUS)) !=
125 			    MDIO_STAT1_LSTATUS)
126 				return false;
127 		}
128 	}
129 
130 	return true;
131 }
132 EXPORT_SYMBOL(mdio45_links_ok);
133 
134 /**
135  * mdio45_nway_restart - restart auto-negotiation for this interface
136  * @mdio: MDIO interface
137  *
138  * Returns 0 on success, negative on error.
139  */
140 int mdio45_nway_restart(const struct mdio_if_info *mdio)
141 {
142 	if (!(mdio->mmds & MDIO_DEVS_AN))
143 		return -EOPNOTSUPP;
144 
145 	mdio_set_flag(mdio, mdio->prtad, MDIO_MMD_AN, MDIO_CTRL1,
146 		      MDIO_AN_CTRL1_RESTART, true);
147 	return 0;
148 }
149 EXPORT_SYMBOL(mdio45_nway_restart);
150 
151 static u32 mdio45_get_an(const struct mdio_if_info *mdio, u16 addr)
152 {
153 	u32 result = 0;
154 	int reg;
155 
156 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN, addr);
157 	if (reg & ADVERTISE_10HALF)
158 		result |= ADVERTISED_10baseT_Half;
159 	if (reg & ADVERTISE_10FULL)
160 		result |= ADVERTISED_10baseT_Full;
161 	if (reg & ADVERTISE_100HALF)
162 		result |= ADVERTISED_100baseT_Half;
163 	if (reg & ADVERTISE_100FULL)
164 		result |= ADVERTISED_100baseT_Full;
165 	return result;
166 }
167 
168 /**
169  * mdio45_ethtool_gset_npage - get settings for ETHTOOL_GSET
170  * @mdio: MDIO interface
171  * @ecmd: Ethtool request structure
172  * @npage_adv: Modes currently advertised on next pages
173  * @npage_lpa: Modes advertised by link partner on next pages
174  *
175  * Since the CSRs for auto-negotiation using next pages are not fully
176  * standardised, this function does not attempt to decode them.  The
177  * caller must pass them in.
178  */
179 void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
180 			       struct ethtool_cmd *ecmd,
181 			       u32 npage_adv, u32 npage_lpa)
182 {
183 	int reg;
184 
185 	ecmd->transceiver = XCVR_INTERNAL;
186 	ecmd->phy_address = mdio->prtad;
187 	ecmd->mdio_support =
188 		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);
189 
190 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
191 			      MDIO_CTRL2);
192 	switch (reg & MDIO_PMA_CTRL2_TYPE) {
193 	case MDIO_PMA_CTRL2_10GBT:
194 	case MDIO_PMA_CTRL2_1000BT:
195 	case MDIO_PMA_CTRL2_100BTX:
196 	case MDIO_PMA_CTRL2_10BT:
197 		ecmd->port = PORT_TP;
198 		ecmd->supported = SUPPORTED_TP;
199 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
200 				      MDIO_SPEED);
201 		if (reg & MDIO_SPEED_10G)
202 			ecmd->supported |= SUPPORTED_10000baseT_Full;
203 		if (reg & MDIO_PMA_SPEED_1000)
204 			ecmd->supported |= (SUPPORTED_1000baseT_Full |
205 					    SUPPORTED_1000baseT_Half);
206 		if (reg & MDIO_PMA_SPEED_100)
207 			ecmd->supported |= (SUPPORTED_100baseT_Full |
208 					    SUPPORTED_100baseT_Half);
209 		if (reg & MDIO_PMA_SPEED_10)
210 			ecmd->supported |= (SUPPORTED_10baseT_Full |
211 					    SUPPORTED_10baseT_Half);
212 		ecmd->advertising = ADVERTISED_TP;
213 		break;
214 
215 	case MDIO_PMA_CTRL2_10GBCX4:
216 		ecmd->port = PORT_OTHER;
217 		ecmd->supported = 0;
218 		ecmd->advertising = 0;
219 		break;
220 
221 	case MDIO_PMA_CTRL2_10GBKX4:
222 	case MDIO_PMA_CTRL2_10GBKR:
223 	case MDIO_PMA_CTRL2_1000BKX:
224 		ecmd->port = PORT_OTHER;
225 		ecmd->supported = SUPPORTED_Backplane;
226 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
227 				      MDIO_PMA_EXTABLE);
228 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
229 			ecmd->supported |= SUPPORTED_10000baseKX4_Full;
230 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
231 			ecmd->supported |= SUPPORTED_10000baseKR_Full;
232 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
233 			ecmd->supported |= SUPPORTED_1000baseKX_Full;
234 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
235 				      MDIO_PMA_10GBR_FECABLE);
236 		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
237 			ecmd->supported |= SUPPORTED_10000baseR_FEC;
238 		ecmd->advertising = ADVERTISED_Backplane;
239 		break;
240 
241 	/* All the other defined modes are flavours of optical */
242 	default:
243 		ecmd->port = PORT_FIBRE;
244 		ecmd->supported = SUPPORTED_FIBRE;
245 		ecmd->advertising = ADVERTISED_FIBRE;
246 		break;
247 	}
248 
249 	if (mdio->mmds & MDIO_DEVS_AN) {
250 		ecmd->supported |= SUPPORTED_Autoneg;
251 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
252 				      MDIO_CTRL1);
253 		if (reg & MDIO_AN_CTRL1_ENABLE) {
254 			ecmd->autoneg = AUTONEG_ENABLE;
255 			ecmd->advertising |=
256 				ADVERTISED_Autoneg |
257 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
258 				npage_adv;
259 		} else {
260 			ecmd->autoneg = AUTONEG_DISABLE;
261 		}
262 	} else {
263 		ecmd->autoneg = AUTONEG_DISABLE;
264 	}
265 
266 	if (ecmd->autoneg) {
267 		u32 modes = 0;
268 		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
269 					      MDIO_MMD_AN, MDIO_STAT1);
270 
271 		/* If AN is complete and successful, report best common
272 		 * mode, otherwise report best advertised mode. */
273 		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
274 			ecmd->lp_advertising =
275 				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
276 			if (an_stat & MDIO_AN_STAT1_LPABLE)
277 				ecmd->lp_advertising |= ADVERTISED_Autoneg;
278 			modes = ecmd->advertising & ecmd->lp_advertising;
279 		}
280 		if ((modes & ~ADVERTISED_Autoneg) == 0)
281 			modes = ecmd->advertising;
282 
283 		if (modes & (ADVERTISED_10000baseT_Full |
284 			     ADVERTISED_10000baseKX4_Full |
285 			     ADVERTISED_10000baseKR_Full)) {
286 			ecmd->speed = SPEED_10000;
287 			ecmd->duplex = DUPLEX_FULL;
288 		} else if (modes & (ADVERTISED_1000baseT_Full |
289 				    ADVERTISED_1000baseT_Half |
290 				    ADVERTISED_1000baseKX_Full)) {
291 			ecmd->speed = SPEED_1000;
292 			ecmd->duplex = !(modes & ADVERTISED_1000baseT_Half);
293 		} else if (modes & (ADVERTISED_100baseT_Full |
294 				    ADVERTISED_100baseT_Half)) {
295 			ecmd->speed = SPEED_100;
296 			ecmd->duplex = !!(modes & ADVERTISED_100baseT_Full);
297 		} else {
298 			ecmd->speed = SPEED_10;
299 			ecmd->duplex = !!(modes & ADVERTISED_10baseT_Full);
300 		}
301 	} else {
302 		/* Report forced settings */
303 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
304 				      MDIO_CTRL1);
305 		ecmd->speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1) *
306 			       ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));
307 		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||
308 				ecmd->speed == SPEED_10000);
309 	}
310 
311 	/* 10GBASE-T MDI/MDI-X */
312 	if (ecmd->port == PORT_TP && ecmd->speed == SPEED_10000) {
313 		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
314 					MDIO_PMA_10GBT_SWAPPOL)) {
315 		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
316 			ecmd->eth_tp_mdix = ETH_TP_MDI;
317 			break;
318 		case 0:
319 			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
320 			break;
321 		default:
322 			/* It's complicated... */
323 			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
324 			break;
325 		}
326 	}
327 }
328 EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
329 
330 /**
331  * mdio45_ethtool_spauseparam_an - set auto-negotiated pause parameters
332  * @mdio: MDIO interface
333  * @ecmd: Ethtool request structure
334  *
335  * This function assumes that the PHY has an auto-negotiation MMD.  It
336  * will enable and disable advertising of flow control as appropriate.
337  */
338 void mdio45_ethtool_spauseparam_an(const struct mdio_if_info *mdio,
339 				   const struct ethtool_pauseparam *ecmd)
340 {
341 	int adv, old_adv;
342 
343 	WARN_ON(!(mdio->mmds & MDIO_DEVS_AN));
344 
345 	old_adv = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
346 				  MDIO_AN_ADVERTISE);
347 	adv = old_adv & ~(ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM);
348 	if (ecmd->autoneg)
349 		adv |= mii_advertise_flowctrl(
350 			(ecmd->rx_pause ? FLOW_CTRL_RX : 0) |
351 			(ecmd->tx_pause ? FLOW_CTRL_TX : 0));
352 	if (adv != old_adv) {
353 		mdio->mdio_write(mdio->dev, mdio->prtad, MDIO_MMD_AN,
354 				 MDIO_AN_ADVERTISE, adv);
355 		mdio45_nway_restart(mdio);
356 	}
357 }
358 EXPORT_SYMBOL(mdio45_ethtool_spauseparam_an);
359 
360 /**
361  * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
362  * @mdio: MDIO interface
363  * @mii_data: MII ioctl data structure
364  * @cmd: MII ioctl command
365  *
366  * Returns 0 on success, negative on error.
367  */
368 int mdio_mii_ioctl(const struct mdio_if_info *mdio,
369 		   struct mii_ioctl_data *mii_data, int cmd)
370 {
371 	int prtad, devad;
372 	u16 addr = mii_data->reg_num;
373 
374 	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
375 	switch (cmd) {
376 	case SIOCGMIIPHY:
377 		if (mdio->prtad == MDIO_PRTAD_NONE)
378 			return -EOPNOTSUPP;
379 		mii_data->phy_id = mdio->prtad;
380 		cmd = SIOCGMIIREG;
381 		break;
382 	case SIOCGMIIREG:
383 	case SIOCSMIIREG:
384 		break;
385 	default:
386 		return -EOPNOTSUPP;
387 	}
388 
389 	/* Validate/convert phy_id */
390 	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
391 	    mdio_phy_id_is_c45(mii_data->phy_id)) {
392 		prtad = mdio_phy_id_prtad(mii_data->phy_id);
393 		devad = mdio_phy_id_devad(mii_data->phy_id);
394 	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
395 		   mii_data->phy_id < 0x20) {
396 		prtad = mii_data->phy_id;
397 		devad = MDIO_DEVAD_NONE;
398 		addr &= 0x1f;
399 	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
400 		   mdio->prtad != MDIO_PRTAD_NONE &&
401 		   mii_data->phy_id == mdio->prtad) {
402 		/* Remap commonly-used MII registers. */
403 		prtad = mdio->prtad;
404 		switch (addr) {
405 		case MII_BMCR:
406 		case MII_BMSR:
407 		case MII_PHYSID1:
408 		case MII_PHYSID2:
409 			devad = __ffs(mdio->mmds);
410 			break;
411 		case MII_ADVERTISE:
412 		case MII_LPA:
413 			if (!(mdio->mmds & MDIO_DEVS_AN))
414 				return -EINVAL;
415 			devad = MDIO_MMD_AN;
416 			if (addr == MII_ADVERTISE)
417 				addr = MDIO_AN_ADVERTISE;
418 			else
419 				addr = MDIO_AN_LPA;
420 			break;
421 		default:
422 			return -EINVAL;
423 		}
424 	} else {
425 		return -EINVAL;
426 	}
427 
428 	if (cmd == SIOCGMIIREG) {
429 		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
430 		if (rc < 0)
431 			return rc;
432 		mii_data->val_out = rc;
433 		return 0;
434 	} else {
435 		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
436 					mii_data->val_in);
437 	}
438 }
439 EXPORT_SYMBOL(mdio_mii_ioctl);
440