xref: /openbmc/linux/drivers/net/mdio.c (revision 81d67439)
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 	if (reg & ADVERTISE_PAUSE_CAP)
166 		result |= ADVERTISED_Pause;
167 	if (reg & ADVERTISE_PAUSE_ASYM)
168 		result |= ADVERTISED_Asym_Pause;
169 	return result;
170 }
171 
172 /**
173  * mdio45_ethtool_gset_npage - get settings for ETHTOOL_GSET
174  * @mdio: MDIO interface
175  * @ecmd: Ethtool request structure
176  * @npage_adv: Modes currently advertised on next pages
177  * @npage_lpa: Modes advertised by link partner on next pages
178  *
179  * The @ecmd parameter is expected to have been cleared before calling
180  * mdio45_ethtool_gset_npage().
181  *
182  * Since the CSRs for auto-negotiation using next pages are not fully
183  * standardised, this function does not attempt to decode them.  The
184  * caller must pass them in.
185  */
186 void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
187 			       struct ethtool_cmd *ecmd,
188 			       u32 npage_adv, u32 npage_lpa)
189 {
190 	int reg;
191 	u32 speed;
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_spauseparam_an - set auto-negotiated pause parameters
343  * @mdio: MDIO interface
344  * @ecmd: Ethtool request structure
345  *
346  * This function assumes that the PHY has an auto-negotiation MMD.  It
347  * will enable and disable advertising of flow control as appropriate.
348  */
349 void mdio45_ethtool_spauseparam_an(const struct mdio_if_info *mdio,
350 				   const struct ethtool_pauseparam *ecmd)
351 {
352 	int adv, old_adv;
353 
354 	WARN_ON(!(mdio->mmds & MDIO_DEVS_AN));
355 
356 	old_adv = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
357 				  MDIO_AN_ADVERTISE);
358 	adv = ((old_adv & ~(ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM)) |
359 	       mii_advertise_flowctrl((ecmd->rx_pause ? FLOW_CTRL_RX : 0) |
360 				      (ecmd->tx_pause ? FLOW_CTRL_TX : 0)));
361 	if (adv != old_adv) {
362 		mdio->mdio_write(mdio->dev, mdio->prtad, MDIO_MMD_AN,
363 				 MDIO_AN_ADVERTISE, adv);
364 		mdio45_nway_restart(mdio);
365 	}
366 }
367 EXPORT_SYMBOL(mdio45_ethtool_spauseparam_an);
368 
369 /**
370  * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
371  * @mdio: MDIO interface
372  * @mii_data: MII ioctl data structure
373  * @cmd: MII ioctl command
374  *
375  * Returns 0 on success, negative on error.
376  */
377 int mdio_mii_ioctl(const struct mdio_if_info *mdio,
378 		   struct mii_ioctl_data *mii_data, int cmd)
379 {
380 	int prtad, devad;
381 	u16 addr = mii_data->reg_num;
382 
383 	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
384 	switch (cmd) {
385 	case SIOCGMIIPHY:
386 		if (mdio->prtad == MDIO_PRTAD_NONE)
387 			return -EOPNOTSUPP;
388 		mii_data->phy_id = mdio->prtad;
389 		cmd = SIOCGMIIREG;
390 		break;
391 	case SIOCGMIIREG:
392 	case SIOCSMIIREG:
393 		break;
394 	default:
395 		return -EOPNOTSUPP;
396 	}
397 
398 	/* Validate/convert phy_id */
399 	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
400 	    mdio_phy_id_is_c45(mii_data->phy_id)) {
401 		prtad = mdio_phy_id_prtad(mii_data->phy_id);
402 		devad = mdio_phy_id_devad(mii_data->phy_id);
403 	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
404 		   mii_data->phy_id < 0x20) {
405 		prtad = mii_data->phy_id;
406 		devad = MDIO_DEVAD_NONE;
407 		addr &= 0x1f;
408 	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
409 		   mdio->prtad != MDIO_PRTAD_NONE &&
410 		   mii_data->phy_id == mdio->prtad) {
411 		/* Remap commonly-used MII registers. */
412 		prtad = mdio->prtad;
413 		switch (addr) {
414 		case MII_BMCR:
415 		case MII_BMSR:
416 		case MII_PHYSID1:
417 		case MII_PHYSID2:
418 			devad = __ffs(mdio->mmds);
419 			break;
420 		case MII_ADVERTISE:
421 		case MII_LPA:
422 			if (!(mdio->mmds & MDIO_DEVS_AN))
423 				return -EINVAL;
424 			devad = MDIO_MMD_AN;
425 			if (addr == MII_ADVERTISE)
426 				addr = MDIO_AN_ADVERTISE;
427 			else
428 				addr = MDIO_AN_LPA;
429 			break;
430 		default:
431 			return -EINVAL;
432 		}
433 	} else {
434 		return -EINVAL;
435 	}
436 
437 	if (cmd == SIOCGMIIREG) {
438 		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
439 		if (rc < 0)
440 			return rc;
441 		mii_data->val_out = rc;
442 		return 0;
443 	} else {
444 		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
445 					mii_data->val_in);
446 	}
447 }
448 EXPORT_SYMBOL(mdio_mii_ioctl);
449