xref: /linux/drivers/net/mdio.c (revision e27ecdd94d81e5bc3d1f68591701db5adb342f0d)
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 /**
18  * mdio45_probe - probe for an MDIO (clause 45) device
19  * @mdio: MDIO interface
20  * @prtad: Expected PHY address
21  *
22  * This sets @prtad and @mmds in the MDIO interface if successful.
23  * Returns 0 on success, negative on error.
24  */
25 int mdio45_probe(struct mdio_if_info *mdio, int prtad)
26 {
27 	int mmd, stat2, devs1, devs2;
28 
29 	/* Assume PHY must have at least one of PMA/PMD, WIS, PCS, PHY
30 	 * XS or DTE XS; give up if none is present. */
31 	for (mmd = 1; mmd <= 5; mmd++) {
32 		/* Is this MMD present? */
33 		stat2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_STAT2);
34 		if (stat2 < 0 ||
35 		    (stat2 & MDIO_STAT2_DEVPRST) != MDIO_STAT2_DEVPRST_VAL)
36 			continue;
37 
38 		/* It should tell us about all the other MMDs */
39 		devs1 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS1);
40 		devs2 = mdio->mdio_read(mdio->dev, prtad, mmd, MDIO_DEVS2);
41 		if (devs1 < 0 || devs2 < 0)
42 			continue;
43 
44 		mdio->prtad = prtad;
45 		mdio->mmds = devs1 | (devs2 << 16);
46 		return 0;
47 	}
48 
49 	return -ENODEV;
50 }
51 EXPORT_SYMBOL(mdio45_probe);
52 
53 /**
54  * mdio_set_flag - set or clear flag in an MDIO register
55  * @mdio: MDIO interface
56  * @prtad: PHY address
57  * @devad: MMD address
58  * @addr: Register address
59  * @mask: Mask for flag (single bit set)
60  * @sense: New value of flag
61  *
62  * This debounces changes: it does not write the register if the flag
63  * already has the proper value.  Returns 0 on success, negative on error.
64  */
65 int mdio_set_flag(const struct mdio_if_info *mdio,
66 		  int prtad, int devad, u16 addr, int mask,
67 		  bool sense)
68 {
69 	int old_val = mdio->mdio_read(mdio->dev, prtad, devad, addr);
70 	int new_val;
71 
72 	if (old_val < 0)
73 		return old_val;
74 	if (sense)
75 		new_val = old_val | mask;
76 	else
77 		new_val = old_val & ~mask;
78 	if (old_val == new_val)
79 		return 0;
80 	return mdio->mdio_write(mdio->dev, prtad, devad, addr, new_val);
81 }
82 EXPORT_SYMBOL(mdio_set_flag);
83 
84 /**
85  * mdio_link_ok - is link status up/OK
86  * @mdio: MDIO interface
87  * @mmd_mask: Mask for MMDs to check
88  *
89  * Returns 1 if the PHY reports link status up/OK, 0 otherwise.
90  * @mmd_mask is normally @mdio->mmds, but if loopback is enabled
91  * the MMDs being bypassed should be excluded from the mask.
92  */
93 int mdio45_links_ok(const struct mdio_if_info *mdio, u32 mmd_mask)
94 {
95 	int devad, reg;
96 
97 	if (!mmd_mask) {
98 		/* Use absence of XGMII faults in lieu of link state */
99 		reg = mdio->mdio_read(mdio->dev, mdio->prtad,
100 				      MDIO_MMD_PHYXS, MDIO_STAT2);
101 		return reg >= 0 && !(reg & MDIO_STAT2_RXFAULT);
102 	}
103 
104 	for (devad = 0; mmd_mask; devad++) {
105 		if (mmd_mask & (1 << devad)) {
106 			mmd_mask &= ~(1 << devad);
107 
108 			/* Read twice because link state is latched and a
109 			 * read moves the current state into the register */
110 			mdio->mdio_read(mdio->dev, mdio->prtad,
111 					devad, MDIO_STAT1);
112 			reg = mdio->mdio_read(mdio->dev, mdio->prtad,
113 					      devad, MDIO_STAT1);
114 			if (reg < 0 || !(reg & MDIO_STAT1_LSTATUS))
115 				return false;
116 		}
117 	}
118 
119 	return true;
120 }
121 EXPORT_SYMBOL(mdio45_links_ok);
122 
123 /**
124  * mdio45_nway_restart - restart auto-negotiation for this interface
125  * @mdio: MDIO interface
126  *
127  * Returns 0 on success, negative on error.
128  */
129 int mdio45_nway_restart(const struct mdio_if_info *mdio)
130 {
131 	if (!(mdio->mmds & MDIO_DEVS_AN))
132 		return -EOPNOTSUPP;
133 
134 	mdio_set_flag(mdio, mdio->prtad, MDIO_MMD_AN, MDIO_CTRL1,
135 		      MDIO_AN_CTRL1_RESTART, true);
136 	return 0;
137 }
138 EXPORT_SYMBOL(mdio45_nway_restart);
139 
140 static u32 mdio45_get_an(const struct mdio_if_info *mdio, u16 addr)
141 {
142 	u32 result = 0;
143 	int reg;
144 
145 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN, addr);
146 	if (reg & ADVERTISE_10HALF)
147 		result |= ADVERTISED_10baseT_Half;
148 	if (reg & ADVERTISE_10FULL)
149 		result |= ADVERTISED_10baseT_Full;
150 	if (reg & ADVERTISE_100HALF)
151 		result |= ADVERTISED_100baseT_Half;
152 	if (reg & ADVERTISE_100FULL)
153 		result |= ADVERTISED_100baseT_Full;
154 	return result;
155 }
156 
157 /**
158  * mdio45_ethtool_gset_npage - get settings for ETHTOOL_GSET
159  * @mdio: MDIO interface
160  * @ecmd: Ethtool request structure
161  * @npage_adv: Modes currently advertised on next pages
162  * @npage_lpa: Modes advertised by link partner on next pages
163  *
164  * Since the CSRs for auto-negotiation using next pages are not fully
165  * standardised, this function does not attempt to decode them.  The
166  * caller must pass them in.
167  */
168 void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
169 			       struct ethtool_cmd *ecmd,
170 			       u32 npage_adv, u32 npage_lpa)
171 {
172 	int reg;
173 
174 	ecmd->transceiver = XCVR_INTERNAL;
175 	ecmd->phy_address = mdio->prtad;
176 	ecmd->mdio_support =
177 		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);
178 
179 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
180 			      MDIO_CTRL2);
181 	switch (reg & MDIO_PMA_CTRL2_TYPE) {
182 	case MDIO_PMA_CTRL2_10GBT:
183 	case MDIO_PMA_CTRL2_1000BT:
184 	case MDIO_PMA_CTRL2_100BTX:
185 	case MDIO_PMA_CTRL2_10BT:
186 		ecmd->port = PORT_TP;
187 		ecmd->supported = SUPPORTED_TP;
188 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
189 				      MDIO_SPEED);
190 		if (reg & MDIO_SPEED_10G)
191 			ecmd->supported |= SUPPORTED_10000baseT_Full;
192 		if (reg & MDIO_PMA_SPEED_1000)
193 			ecmd->supported |= (SUPPORTED_1000baseT_Full |
194 					    SUPPORTED_1000baseT_Half);
195 		if (reg & MDIO_PMA_SPEED_100)
196 			ecmd->supported |= (SUPPORTED_100baseT_Full |
197 					    SUPPORTED_100baseT_Half);
198 		if (reg & MDIO_PMA_SPEED_10)
199 			ecmd->supported |= (SUPPORTED_10baseT_Full |
200 					    SUPPORTED_10baseT_Half);
201 		ecmd->advertising = ADVERTISED_TP;
202 		break;
203 
204 	case MDIO_PMA_CTRL2_10GBCX4:
205 		ecmd->port = PORT_OTHER;
206 		ecmd->supported = 0;
207 		ecmd->advertising = 0;
208 		break;
209 
210 	case MDIO_PMA_CTRL2_10GBKX4:
211 	case MDIO_PMA_CTRL2_10GBKR:
212 	case MDIO_PMA_CTRL2_1000BKX:
213 		ecmd->port = PORT_OTHER;
214 		ecmd->supported = SUPPORTED_Backplane;
215 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
216 				      MDIO_PMA_EXTABLE);
217 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
218 			ecmd->supported |= SUPPORTED_10000baseKX4_Full;
219 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
220 			ecmd->supported |= SUPPORTED_10000baseKR_Full;
221 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
222 			ecmd->supported |= SUPPORTED_1000baseKX_Full;
223 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
224 				      MDIO_PMA_10GBR_FECABLE);
225 		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
226 			ecmd->supported |= SUPPORTED_10000baseR_FEC;
227 		ecmd->advertising = ADVERTISED_Backplane;
228 		break;
229 
230 	/* All the other defined modes are flavours of optical */
231 	default:
232 		ecmd->port = PORT_FIBRE;
233 		ecmd->supported = SUPPORTED_FIBRE;
234 		ecmd->advertising = ADVERTISED_FIBRE;
235 		break;
236 	}
237 
238 	if (mdio->mmds & MDIO_DEVS_AN) {
239 		ecmd->supported |= SUPPORTED_Autoneg;
240 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
241 				      MDIO_CTRL1);
242 		if (reg & MDIO_AN_CTRL1_ENABLE) {
243 			ecmd->autoneg = AUTONEG_ENABLE;
244 			ecmd->advertising |=
245 				ADVERTISED_Autoneg |
246 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
247 				npage_adv;
248 		} else {
249 			ecmd->autoneg = AUTONEG_DISABLE;
250 		}
251 	} else {
252 		ecmd->autoneg = AUTONEG_DISABLE;
253 	}
254 
255 	if (ecmd->autoneg) {
256 		u32 modes = 0;
257 		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
258 					      MDIO_MMD_AN, MDIO_STAT1);
259 
260 		/* If AN is complete and successful, report best common
261 		 * mode, otherwise report best advertised mode. */
262 		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
263 			ecmd->lp_advertising =
264 				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
265 			if (an_stat & MDIO_AN_STAT1_LPABLE)
266 				ecmd->lp_advertising |= ADVERTISED_Autoneg;
267 			modes = ecmd->advertising & ecmd->lp_advertising;
268 		}
269 		if ((modes & ~ADVERTISED_Autoneg) == 0)
270 			modes = ecmd->advertising;
271 
272 		if (modes & (ADVERTISED_10000baseT_Full |
273 			     ADVERTISED_10000baseKX4_Full |
274 			     ADVERTISED_10000baseKR_Full)) {
275 			ecmd->speed = SPEED_10000;
276 			ecmd->duplex = DUPLEX_FULL;
277 		} else if (modes & (ADVERTISED_1000baseT_Full |
278 				    ADVERTISED_1000baseT_Half |
279 				    ADVERTISED_1000baseKX_Full)) {
280 			ecmd->speed = SPEED_1000;
281 			ecmd->duplex = !(modes & ADVERTISED_1000baseT_Half);
282 		} else if (modes & (ADVERTISED_100baseT_Full |
283 				    ADVERTISED_100baseT_Half)) {
284 			ecmd->speed = SPEED_100;
285 			ecmd->duplex = !!(modes & ADVERTISED_100baseT_Full);
286 		} else {
287 			ecmd->speed = SPEED_10;
288 			ecmd->duplex = !!(modes & ADVERTISED_10baseT_Full);
289 		}
290 	} else {
291 		/* Report forced settings */
292 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
293 				      MDIO_CTRL1);
294 		ecmd->speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1) *
295 			       ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));
296 		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||
297 				ecmd->speed == SPEED_10000);
298 	}
299 
300 	/* 10GBASE-T MDI/MDI-X */
301 	if (ecmd->port == PORT_TP && ecmd->speed == SPEED_10000) {
302 		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
303 					MDIO_PMA_10GBT_SWAPPOL)) {
304 		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
305 			ecmd->eth_tp_mdix = ETH_TP_MDI;
306 			break;
307 		case 0:
308 			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
309 			break;
310 		default:
311 			/* It's complicated... */
312 			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
313 			break;
314 		}
315 	}
316 }
317 EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
318 
319 /**
320  * mdio45_ethtool_spauseparam_an - set auto-negotiated pause parameters
321  * @mdio: MDIO interface
322  * @ecmd: Ethtool request structure
323  *
324  * This function assumes that the PHY has an auto-negotiation MMD.  It
325  * will enable and disable advertising of flow control as appropriate.
326  */
327 void mdio45_ethtool_spauseparam_an(const struct mdio_if_info *mdio,
328 				   const struct ethtool_pauseparam *ecmd)
329 {
330 	int adv, old_adv;
331 
332 	WARN_ON(!(mdio->mmds & MDIO_DEVS_AN));
333 
334 	old_adv = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
335 				  MDIO_AN_ADVERTISE);
336 	adv = old_adv & ~(ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM);
337 	if (ecmd->autoneg)
338 		adv |= mii_advertise_flowctrl(
339 			(ecmd->rx_pause ? FLOW_CTRL_RX : 0) |
340 			(ecmd->tx_pause ? FLOW_CTRL_TX : 0));
341 	if (adv != old_adv) {
342 		mdio->mdio_write(mdio->dev, mdio->prtad, MDIO_MMD_AN,
343 				 MDIO_AN_ADVERTISE, adv);
344 		mdio45_nway_restart(mdio);
345 	}
346 }
347 EXPORT_SYMBOL(mdio45_ethtool_spauseparam_an);
348 
349 /**
350  * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
351  * @mdio: MDIO interface
352  * @mii_data: MII ioctl data structure
353  * @cmd: MII ioctl command
354  *
355  * Returns 0 on success, negative on error.
356  */
357 int mdio_mii_ioctl(const struct mdio_if_info *mdio,
358 		   struct mii_ioctl_data *mii_data, int cmd)
359 {
360 	int prtad, devad;
361 	u16 addr = mii_data->reg_num;
362 
363 	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
364 	switch (cmd) {
365 	case SIOCGMIIPHY:
366 		if (mdio->prtad == MDIO_PRTAD_NONE)
367 			return -EOPNOTSUPP;
368 		mii_data->phy_id = mdio->prtad;
369 		cmd = SIOCGMIIREG;
370 		break;
371 	case SIOCGMIIREG:
372 		break;
373 	case SIOCSMIIREG:
374 		if (!capable(CAP_NET_ADMIN))
375 			return -EPERM;
376 		break;
377 	default:
378 		return -EOPNOTSUPP;
379 	}
380 
381 	/* Validate/convert phy_id */
382 	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
383 	    mdio_phy_id_is_c45(mii_data->phy_id)) {
384 		prtad = mdio_phy_id_prtad(mii_data->phy_id);
385 		devad = mdio_phy_id_devad(mii_data->phy_id);
386 	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
387 		   mii_data->phy_id < 0x20) {
388 		prtad = mii_data->phy_id;
389 		devad = MDIO_DEVAD_NONE;
390 		addr &= 0x1f;
391 	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
392 		   mdio->prtad != MDIO_PRTAD_NONE &&
393 		   mii_data->phy_id == mdio->prtad) {
394 		/* Remap commonly-used MII registers. */
395 		prtad = mdio->prtad;
396 		switch (addr) {
397 		case MII_BMCR:
398 		case MII_BMSR:
399 		case MII_PHYSID1:
400 		case MII_PHYSID2:
401 			devad = __ffs(mdio->mmds);
402 			break;
403 		case MII_ADVERTISE:
404 		case MII_LPA:
405 			if (!(mdio->mmds & MDIO_DEVS_AN))
406 				return -EINVAL;
407 			devad = MDIO_MMD_AN;
408 			if (addr == MII_ADVERTISE)
409 				addr = MDIO_AN_ADVERTISE;
410 			else
411 				addr = MDIO_AN_LPA;
412 			break;
413 		default:
414 			return -EINVAL;
415 		}
416 	} else {
417 		return -EINVAL;
418 	}
419 
420 	if (cmd == SIOCGMIIREG) {
421 		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
422 		if (rc < 0)
423 			return rc;
424 		mii_data->val_out = rc;
425 		return 0;
426 	} else {
427 		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
428 					mii_data->val_in);
429 	}
430 }
431 EXPORT_SYMBOL(mdio_mii_ioctl);
432