xref: /openbmc/linux/drivers/net/mdio.c (revision 483eb062)
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 	BUILD_BUG_ON(MDIO_SUPPORTS_C22 != ETH_MDIO_SUPPORTS_C22);
194 	BUILD_BUG_ON(MDIO_SUPPORTS_C45 != ETH_MDIO_SUPPORTS_C45);
195 
196 	ecmd->transceiver = XCVR_INTERNAL;
197 	ecmd->phy_address = mdio->prtad;
198 	ecmd->mdio_support =
199 		mdio->mode_support & (MDIO_SUPPORTS_C45 | MDIO_SUPPORTS_C22);
200 
201 	reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
202 			      MDIO_CTRL2);
203 	switch (reg & MDIO_PMA_CTRL2_TYPE) {
204 	case MDIO_PMA_CTRL2_10GBT:
205 	case MDIO_PMA_CTRL2_1000BT:
206 	case MDIO_PMA_CTRL2_100BTX:
207 	case MDIO_PMA_CTRL2_10BT:
208 		ecmd->port = PORT_TP;
209 		ecmd->supported = SUPPORTED_TP;
210 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
211 				      MDIO_SPEED);
212 		if (reg & MDIO_SPEED_10G)
213 			ecmd->supported |= SUPPORTED_10000baseT_Full;
214 		if (reg & MDIO_PMA_SPEED_1000)
215 			ecmd->supported |= (SUPPORTED_1000baseT_Full |
216 					    SUPPORTED_1000baseT_Half);
217 		if (reg & MDIO_PMA_SPEED_100)
218 			ecmd->supported |= (SUPPORTED_100baseT_Full |
219 					    SUPPORTED_100baseT_Half);
220 		if (reg & MDIO_PMA_SPEED_10)
221 			ecmd->supported |= (SUPPORTED_10baseT_Full |
222 					    SUPPORTED_10baseT_Half);
223 		ecmd->advertising = ADVERTISED_TP;
224 		break;
225 
226 	case MDIO_PMA_CTRL2_10GBCX4:
227 		ecmd->port = PORT_OTHER;
228 		ecmd->supported = 0;
229 		ecmd->advertising = 0;
230 		break;
231 
232 	case MDIO_PMA_CTRL2_10GBKX4:
233 	case MDIO_PMA_CTRL2_10GBKR:
234 	case MDIO_PMA_CTRL2_1000BKX:
235 		ecmd->port = PORT_OTHER;
236 		ecmd->supported = SUPPORTED_Backplane;
237 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
238 				      MDIO_PMA_EXTABLE);
239 		if (reg & MDIO_PMA_EXTABLE_10GBKX4)
240 			ecmd->supported |= SUPPORTED_10000baseKX4_Full;
241 		if (reg & MDIO_PMA_EXTABLE_10GBKR)
242 			ecmd->supported |= SUPPORTED_10000baseKR_Full;
243 		if (reg & MDIO_PMA_EXTABLE_1000BKX)
244 			ecmd->supported |= SUPPORTED_1000baseKX_Full;
245 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
246 				      MDIO_PMA_10GBR_FECABLE);
247 		if (reg & MDIO_PMA_10GBR_FECABLE_ABLE)
248 			ecmd->supported |= SUPPORTED_10000baseR_FEC;
249 		ecmd->advertising = ADVERTISED_Backplane;
250 		break;
251 
252 	/* All the other defined modes are flavours of optical */
253 	default:
254 		ecmd->port = PORT_FIBRE;
255 		ecmd->supported = SUPPORTED_FIBRE;
256 		ecmd->advertising = ADVERTISED_FIBRE;
257 		break;
258 	}
259 
260 	if (mdio->mmds & MDIO_DEVS_AN) {
261 		ecmd->supported |= SUPPORTED_Autoneg;
262 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_AN,
263 				      MDIO_CTRL1);
264 		if (reg & MDIO_AN_CTRL1_ENABLE) {
265 			ecmd->autoneg = AUTONEG_ENABLE;
266 			ecmd->advertising |=
267 				ADVERTISED_Autoneg |
268 				mdio45_get_an(mdio, MDIO_AN_ADVERTISE) |
269 				npage_adv;
270 		} else {
271 			ecmd->autoneg = AUTONEG_DISABLE;
272 		}
273 	} else {
274 		ecmd->autoneg = AUTONEG_DISABLE;
275 	}
276 
277 	if (ecmd->autoneg) {
278 		u32 modes = 0;
279 		int an_stat = mdio->mdio_read(mdio->dev, mdio->prtad,
280 					      MDIO_MMD_AN, MDIO_STAT1);
281 
282 		/* If AN is complete and successful, report best common
283 		 * mode, otherwise report best advertised mode. */
284 		if (an_stat & MDIO_AN_STAT1_COMPLETE) {
285 			ecmd->lp_advertising =
286 				mdio45_get_an(mdio, MDIO_AN_LPA) | npage_lpa;
287 			if (an_stat & MDIO_AN_STAT1_LPABLE)
288 				ecmd->lp_advertising |= ADVERTISED_Autoneg;
289 			modes = ecmd->advertising & ecmd->lp_advertising;
290 		}
291 		if ((modes & ~ADVERTISED_Autoneg) == 0)
292 			modes = ecmd->advertising;
293 
294 		if (modes & (ADVERTISED_10000baseT_Full |
295 			     ADVERTISED_10000baseKX4_Full |
296 			     ADVERTISED_10000baseKR_Full)) {
297 			speed = SPEED_10000;
298 			ecmd->duplex = DUPLEX_FULL;
299 		} else if (modes & (ADVERTISED_1000baseT_Full |
300 				    ADVERTISED_1000baseT_Half |
301 				    ADVERTISED_1000baseKX_Full)) {
302 			speed = SPEED_1000;
303 			ecmd->duplex = !(modes & ADVERTISED_1000baseT_Half);
304 		} else if (modes & (ADVERTISED_100baseT_Full |
305 				    ADVERTISED_100baseT_Half)) {
306 			speed = SPEED_100;
307 			ecmd->duplex = !!(modes & ADVERTISED_100baseT_Full);
308 		} else {
309 			speed = SPEED_10;
310 			ecmd->duplex = !!(modes & ADVERTISED_10baseT_Full);
311 		}
312 	} else {
313 		/* Report forced settings */
314 		reg = mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
315 				      MDIO_CTRL1);
316 		speed = (((reg & MDIO_PMA_CTRL1_SPEED1000) ? 100 : 1)
317 			 * ((reg & MDIO_PMA_CTRL1_SPEED100) ? 100 : 10));
318 		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||
319 				speed == SPEED_10000);
320 	}
321 
322 	ethtool_cmd_speed_set(ecmd, speed);
323 
324 	/* 10GBASE-T MDI/MDI-X */
325 	if (ecmd->port == PORT_TP
326 	    && (ethtool_cmd_speed(ecmd) == SPEED_10000)) {
327 		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
328 					MDIO_PMA_10GBT_SWAPPOL)) {
329 		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
330 			ecmd->eth_tp_mdix = ETH_TP_MDI;
331 			break;
332 		case 0:
333 			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
334 			break;
335 		default:
336 			/* It's complicated... */
337 			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
338 			break;
339 		}
340 	}
341 }
342 EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
343 
344 /**
345  * mdio_mii_ioctl - MII ioctl interface for MDIO (clause 22 or 45) PHYs
346  * @mdio: MDIO interface
347  * @mii_data: MII ioctl data structure
348  * @cmd: MII ioctl command
349  *
350  * Returns 0 on success, negative on error.
351  */
352 int mdio_mii_ioctl(const struct mdio_if_info *mdio,
353 		   struct mii_ioctl_data *mii_data, int cmd)
354 {
355 	int prtad, devad;
356 	u16 addr = mii_data->reg_num;
357 
358 	/* Validate/convert cmd to one of SIOC{G,S}MIIREG */
359 	switch (cmd) {
360 	case SIOCGMIIPHY:
361 		if (mdio->prtad == MDIO_PRTAD_NONE)
362 			return -EOPNOTSUPP;
363 		mii_data->phy_id = mdio->prtad;
364 		cmd = SIOCGMIIREG;
365 		break;
366 	case SIOCGMIIREG:
367 	case SIOCSMIIREG:
368 		break;
369 	default:
370 		return -EOPNOTSUPP;
371 	}
372 
373 	/* Validate/convert phy_id */
374 	if ((mdio->mode_support & MDIO_SUPPORTS_C45) &&
375 	    mdio_phy_id_is_c45(mii_data->phy_id)) {
376 		prtad = mdio_phy_id_prtad(mii_data->phy_id);
377 		devad = mdio_phy_id_devad(mii_data->phy_id);
378 	} else if ((mdio->mode_support & MDIO_SUPPORTS_C22) &&
379 		   mii_data->phy_id < 0x20) {
380 		prtad = mii_data->phy_id;
381 		devad = MDIO_DEVAD_NONE;
382 		addr &= 0x1f;
383 	} else if ((mdio->mode_support & MDIO_EMULATE_C22) &&
384 		   mdio->prtad != MDIO_PRTAD_NONE &&
385 		   mii_data->phy_id == mdio->prtad) {
386 		/* Remap commonly-used MII registers. */
387 		prtad = mdio->prtad;
388 		switch (addr) {
389 		case MII_BMCR:
390 		case MII_BMSR:
391 		case MII_PHYSID1:
392 		case MII_PHYSID2:
393 			devad = __ffs(mdio->mmds);
394 			break;
395 		case MII_ADVERTISE:
396 		case MII_LPA:
397 			if (!(mdio->mmds & MDIO_DEVS_AN))
398 				return -EINVAL;
399 			devad = MDIO_MMD_AN;
400 			if (addr == MII_ADVERTISE)
401 				addr = MDIO_AN_ADVERTISE;
402 			else
403 				addr = MDIO_AN_LPA;
404 			break;
405 		default:
406 			return -EINVAL;
407 		}
408 	} else {
409 		return -EINVAL;
410 	}
411 
412 	if (cmd == SIOCGMIIREG) {
413 		int rc = mdio->mdio_read(mdio->dev, prtad, devad, addr);
414 		if (rc < 0)
415 			return rc;
416 		mii_data->val_out = rc;
417 		return 0;
418 	} else {
419 		return mdio->mdio_write(mdio->dev, prtad, devad, addr,
420 					mii_data->val_in);
421 	}
422 }
423 EXPORT_SYMBOL(mdio_mii_ioctl);
424