xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision e20d5a22)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Core PHY library, taken from phy.c
4  */
5 #include <linux/export.h>
6 #include <linux/phy.h>
7 #include <linux/of.h>
8 
9 /**
10  * phy_speed_to_str - Return a string representing the PHY link speed
11  *
12  * @speed: Speed of the link
13  */
14 const char *phy_speed_to_str(int speed)
15 {
16 	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 99,
17 		"Enum ethtool_link_mode_bit_indices and phylib are out of sync. "
18 		"If a speed or mode has been added please update phy_speed_to_str "
19 		"and the PHY settings array.\n");
20 
21 	switch (speed) {
22 	case SPEED_10:
23 		return "10Mbps";
24 	case SPEED_100:
25 		return "100Mbps";
26 	case SPEED_1000:
27 		return "1Gbps";
28 	case SPEED_2500:
29 		return "2.5Gbps";
30 	case SPEED_5000:
31 		return "5Gbps";
32 	case SPEED_10000:
33 		return "10Gbps";
34 	case SPEED_14000:
35 		return "14Gbps";
36 	case SPEED_20000:
37 		return "20Gbps";
38 	case SPEED_25000:
39 		return "25Gbps";
40 	case SPEED_40000:
41 		return "40Gbps";
42 	case SPEED_50000:
43 		return "50Gbps";
44 	case SPEED_56000:
45 		return "56Gbps";
46 	case SPEED_100000:
47 		return "100Gbps";
48 	case SPEED_200000:
49 		return "200Gbps";
50 	case SPEED_400000:
51 		return "400Gbps";
52 	case SPEED_800000:
53 		return "800Gbps";
54 	case SPEED_UNKNOWN:
55 		return "Unknown";
56 	default:
57 		return "Unsupported (update phy-core.c)";
58 	}
59 }
60 EXPORT_SYMBOL_GPL(phy_speed_to_str);
61 
62 /**
63  * phy_duplex_to_str - Return string describing the duplex
64  *
65  * @duplex: Duplex setting to describe
66  */
67 const char *phy_duplex_to_str(unsigned int duplex)
68 {
69 	if (duplex == DUPLEX_HALF)
70 		return "Half";
71 	if (duplex == DUPLEX_FULL)
72 		return "Full";
73 	if (duplex == DUPLEX_UNKNOWN)
74 		return "Unknown";
75 	return "Unsupported (update phy-core.c)";
76 }
77 EXPORT_SYMBOL_GPL(phy_duplex_to_str);
78 
79 /**
80  * phy_rate_matching_to_str - Return a string describing the rate matching
81  *
82  * @rate_matching: Type of rate matching to describe
83  */
84 const char *phy_rate_matching_to_str(int rate_matching)
85 {
86 	switch (rate_matching) {
87 	case RATE_MATCH_NONE:
88 		return "none";
89 	case RATE_MATCH_PAUSE:
90 		return "pause";
91 	case RATE_MATCH_CRS:
92 		return "crs";
93 	case RATE_MATCH_OPEN_LOOP:
94 		return "open-loop";
95 	}
96 	return "Unsupported (update phy-core.c)";
97 }
98 EXPORT_SYMBOL_GPL(phy_rate_matching_to_str);
99 
100 /**
101  * phy_interface_num_ports - Return the number of links that can be carried by
102  *			     a given MAC-PHY physical link. Returns 0 if this is
103  *			     unknown, the number of links else.
104  *
105  * @interface: The interface mode we want to get the number of ports
106  */
107 int phy_interface_num_ports(phy_interface_t interface)
108 {
109 	switch (interface) {
110 	case PHY_INTERFACE_MODE_NA:
111 		return 0;
112 	case PHY_INTERFACE_MODE_INTERNAL:
113 	case PHY_INTERFACE_MODE_MII:
114 	case PHY_INTERFACE_MODE_GMII:
115 	case PHY_INTERFACE_MODE_TBI:
116 	case PHY_INTERFACE_MODE_REVMII:
117 	case PHY_INTERFACE_MODE_RMII:
118 	case PHY_INTERFACE_MODE_REVRMII:
119 	case PHY_INTERFACE_MODE_RGMII:
120 	case PHY_INTERFACE_MODE_RGMII_ID:
121 	case PHY_INTERFACE_MODE_RGMII_RXID:
122 	case PHY_INTERFACE_MODE_RGMII_TXID:
123 	case PHY_INTERFACE_MODE_RTBI:
124 	case PHY_INTERFACE_MODE_XGMII:
125 	case PHY_INTERFACE_MODE_XLGMII:
126 	case PHY_INTERFACE_MODE_MOCA:
127 	case PHY_INTERFACE_MODE_TRGMII:
128 	case PHY_INTERFACE_MODE_USXGMII:
129 	case PHY_INTERFACE_MODE_SGMII:
130 	case PHY_INTERFACE_MODE_SMII:
131 	case PHY_INTERFACE_MODE_1000BASEX:
132 	case PHY_INTERFACE_MODE_2500BASEX:
133 	case PHY_INTERFACE_MODE_5GBASER:
134 	case PHY_INTERFACE_MODE_10GBASER:
135 	case PHY_INTERFACE_MODE_25GBASER:
136 	case PHY_INTERFACE_MODE_10GKR:
137 	case PHY_INTERFACE_MODE_100BASEX:
138 	case PHY_INTERFACE_MODE_RXAUI:
139 	case PHY_INTERFACE_MODE_XAUI:
140 	case PHY_INTERFACE_MODE_1000BASEKX:
141 		return 1;
142 	case PHY_INTERFACE_MODE_QSGMII:
143 	case PHY_INTERFACE_MODE_QUSGMII:
144 		return 4;
145 	case PHY_INTERFACE_MODE_MAX:
146 		WARN_ONCE(1, "PHY_INTERFACE_MODE_MAX isn't a valid interface mode");
147 		return 0;
148 	}
149 	return 0;
150 }
151 EXPORT_SYMBOL_GPL(phy_interface_num_ports);
152 
153 /* A mapping of all SUPPORTED settings to speed/duplex.  This table
154  * must be grouped by speed and sorted in descending match priority
155  * - iow, descending speed.
156  */
157 
158 #define PHY_SETTING(s, d, b) { .speed = SPEED_ ## s, .duplex = DUPLEX_ ## d, \
159 			       .bit = ETHTOOL_LINK_MODE_ ## b ## _BIT}
160 
161 static const struct phy_setting settings[] = {
162 	/* 800G */
163 	PHY_SETTING( 800000, FULL, 800000baseCR8_Full		),
164 	PHY_SETTING( 800000, FULL, 800000baseKR8_Full		),
165 	PHY_SETTING( 800000, FULL, 800000baseDR8_Full		),
166 	PHY_SETTING( 800000, FULL, 800000baseDR8_2_Full		),
167 	PHY_SETTING( 800000, FULL, 800000baseSR8_Full		),
168 	PHY_SETTING( 800000, FULL, 800000baseVR8_Full		),
169 	/* 400G */
170 	PHY_SETTING( 400000, FULL, 400000baseCR8_Full		),
171 	PHY_SETTING( 400000, FULL, 400000baseKR8_Full		),
172 	PHY_SETTING( 400000, FULL, 400000baseLR8_ER8_FR8_Full	),
173 	PHY_SETTING( 400000, FULL, 400000baseDR8_Full		),
174 	PHY_SETTING( 400000, FULL, 400000baseSR8_Full		),
175 	PHY_SETTING( 400000, FULL, 400000baseCR4_Full		),
176 	PHY_SETTING( 400000, FULL, 400000baseKR4_Full		),
177 	PHY_SETTING( 400000, FULL, 400000baseLR4_ER4_FR4_Full	),
178 	PHY_SETTING( 400000, FULL, 400000baseDR4_Full		),
179 	PHY_SETTING( 400000, FULL, 400000baseSR4_Full		),
180 	/* 200G */
181 	PHY_SETTING( 200000, FULL, 200000baseCR4_Full		),
182 	PHY_SETTING( 200000, FULL, 200000baseKR4_Full		),
183 	PHY_SETTING( 200000, FULL, 200000baseLR4_ER4_FR4_Full	),
184 	PHY_SETTING( 200000, FULL, 200000baseDR4_Full		),
185 	PHY_SETTING( 200000, FULL, 200000baseSR4_Full		),
186 	PHY_SETTING( 200000, FULL, 200000baseCR2_Full		),
187 	PHY_SETTING( 200000, FULL, 200000baseKR2_Full		),
188 	PHY_SETTING( 200000, FULL, 200000baseLR2_ER2_FR2_Full	),
189 	PHY_SETTING( 200000, FULL, 200000baseDR2_Full		),
190 	PHY_SETTING( 200000, FULL, 200000baseSR2_Full		),
191 	/* 100G */
192 	PHY_SETTING( 100000, FULL, 100000baseCR4_Full		),
193 	PHY_SETTING( 100000, FULL, 100000baseKR4_Full		),
194 	PHY_SETTING( 100000, FULL, 100000baseLR4_ER4_Full	),
195 	PHY_SETTING( 100000, FULL, 100000baseSR4_Full		),
196 	PHY_SETTING( 100000, FULL, 100000baseCR2_Full		),
197 	PHY_SETTING( 100000, FULL, 100000baseKR2_Full		),
198 	PHY_SETTING( 100000, FULL, 100000baseLR2_ER2_FR2_Full	),
199 	PHY_SETTING( 100000, FULL, 100000baseDR2_Full		),
200 	PHY_SETTING( 100000, FULL, 100000baseSR2_Full		),
201 	PHY_SETTING( 100000, FULL, 100000baseCR_Full		),
202 	PHY_SETTING( 100000, FULL, 100000baseKR_Full		),
203 	PHY_SETTING( 100000, FULL, 100000baseLR_ER_FR_Full	),
204 	PHY_SETTING( 100000, FULL, 100000baseDR_Full		),
205 	PHY_SETTING( 100000, FULL, 100000baseSR_Full		),
206 	/* 56G */
207 	PHY_SETTING(  56000, FULL,  56000baseCR4_Full	  	),
208 	PHY_SETTING(  56000, FULL,  56000baseKR4_Full	  	),
209 	PHY_SETTING(  56000, FULL,  56000baseLR4_Full	  	),
210 	PHY_SETTING(  56000, FULL,  56000baseSR4_Full	  	),
211 	/* 50G */
212 	PHY_SETTING(  50000, FULL,  50000baseCR2_Full		),
213 	PHY_SETTING(  50000, FULL,  50000baseKR2_Full		),
214 	PHY_SETTING(  50000, FULL,  50000baseSR2_Full		),
215 	PHY_SETTING(  50000, FULL,  50000baseCR_Full		),
216 	PHY_SETTING(  50000, FULL,  50000baseKR_Full		),
217 	PHY_SETTING(  50000, FULL,  50000baseLR_ER_FR_Full	),
218 	PHY_SETTING(  50000, FULL,  50000baseDR_Full		),
219 	PHY_SETTING(  50000, FULL,  50000baseSR_Full		),
220 	/* 40G */
221 	PHY_SETTING(  40000, FULL,  40000baseCR4_Full		),
222 	PHY_SETTING(  40000, FULL,  40000baseKR4_Full		),
223 	PHY_SETTING(  40000, FULL,  40000baseLR4_Full		),
224 	PHY_SETTING(  40000, FULL,  40000baseSR4_Full		),
225 	/* 25G */
226 	PHY_SETTING(  25000, FULL,  25000baseCR_Full		),
227 	PHY_SETTING(  25000, FULL,  25000baseKR_Full		),
228 	PHY_SETTING(  25000, FULL,  25000baseSR_Full		),
229 	/* 20G */
230 	PHY_SETTING(  20000, FULL,  20000baseKR2_Full		),
231 	PHY_SETTING(  20000, FULL,  20000baseMLD2_Full		),
232 	/* 10G */
233 	PHY_SETTING(  10000, FULL,  10000baseCR_Full		),
234 	PHY_SETTING(  10000, FULL,  10000baseER_Full		),
235 	PHY_SETTING(  10000, FULL,  10000baseKR_Full		),
236 	PHY_SETTING(  10000, FULL,  10000baseKX4_Full		),
237 	PHY_SETTING(  10000, FULL,  10000baseLR_Full		),
238 	PHY_SETTING(  10000, FULL,  10000baseLRM_Full		),
239 	PHY_SETTING(  10000, FULL,  10000baseR_FEC		),
240 	PHY_SETTING(  10000, FULL,  10000baseSR_Full		),
241 	PHY_SETTING(  10000, FULL,  10000baseT_Full		),
242 	/* 5G */
243 	PHY_SETTING(   5000, FULL,   5000baseT_Full		),
244 	/* 2.5G */
245 	PHY_SETTING(   2500, FULL,   2500baseT_Full		),
246 	PHY_SETTING(   2500, FULL,   2500baseX_Full		),
247 	/* 1G */
248 	PHY_SETTING(   1000, FULL,   1000baseT_Full		),
249 	PHY_SETTING(   1000, HALF,   1000baseT_Half		),
250 	PHY_SETTING(   1000, FULL,   1000baseT1_Full		),
251 	PHY_SETTING(   1000, FULL,   1000baseX_Full		),
252 	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
253 	/* 100M */
254 	PHY_SETTING(    100, FULL,    100baseT_Full		),
255 	PHY_SETTING(    100, FULL,    100baseT1_Full		),
256 	PHY_SETTING(    100, HALF,    100baseT_Half		),
257 	PHY_SETTING(    100, HALF,    100baseFX_Half		),
258 	PHY_SETTING(    100, FULL,    100baseFX_Full		),
259 	/* 10M */
260 	PHY_SETTING(     10, FULL,     10baseT_Full		),
261 	PHY_SETTING(     10, HALF,     10baseT_Half		),
262 	PHY_SETTING(     10, FULL,     10baseT1L_Full		),
263 };
264 #undef PHY_SETTING
265 
266 /**
267  * phy_lookup_setting - lookup a PHY setting
268  * @speed: speed to match
269  * @duplex: duplex to match
270  * @mask: allowed link modes
271  * @exact: an exact match is required
272  *
273  * Search the settings array for a setting that matches the speed and
274  * duplex, and which is supported.
275  *
276  * If @exact is unset, either an exact match or %NULL for no match will
277  * be returned.
278  *
279  * If @exact is set, an exact match, the fastest supported setting at
280  * or below the specified speed, the slowest supported setting, or if
281  * they all fail, %NULL will be returned.
282  */
283 const struct phy_setting *
284 phy_lookup_setting(int speed, int duplex, const unsigned long *mask, bool exact)
285 {
286 	const struct phy_setting *p, *match = NULL, *last = NULL;
287 	int i;
288 
289 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
290 		if (p->bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
291 		    test_bit(p->bit, mask)) {
292 			last = p;
293 			if (p->speed == speed && p->duplex == duplex) {
294 				/* Exact match for speed and duplex */
295 				match = p;
296 				break;
297 			} else if (!exact) {
298 				if (!match && p->speed <= speed)
299 					/* Candidate */
300 					match = p;
301 
302 				if (p->speed < speed)
303 					break;
304 			}
305 		}
306 	}
307 
308 	if (!match && !exact)
309 		match = last;
310 
311 	return match;
312 }
313 EXPORT_SYMBOL_GPL(phy_lookup_setting);
314 
315 size_t phy_speeds(unsigned int *speeds, size_t size,
316 		  unsigned long *mask)
317 {
318 	size_t count;
319 	int i;
320 
321 	for (i = 0, count = 0; i < ARRAY_SIZE(settings) && count < size; i++)
322 		if (settings[i].bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
323 		    test_bit(settings[i].bit, mask) &&
324 		    (count == 0 || speeds[count - 1] != settings[i].speed))
325 			speeds[count++] = settings[i].speed;
326 
327 	return count;
328 }
329 
330 static void __set_linkmode_max_speed(u32 max_speed, unsigned long *addr)
331 {
332 	const struct phy_setting *p;
333 	int i;
334 
335 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
336 		if (p->speed > max_speed)
337 			linkmode_clear_bit(p->bit, addr);
338 		else
339 			break;
340 	}
341 }
342 
343 static void __set_phy_supported(struct phy_device *phydev, u32 max_speed)
344 {
345 	__set_linkmode_max_speed(max_speed, phydev->supported);
346 }
347 
348 /**
349  * phy_set_max_speed - Set the maximum speed the PHY should support
350  *
351  * @phydev: The phy_device struct
352  * @max_speed: Maximum speed
353  *
354  * The PHY might be more capable than the MAC. For example a Fast Ethernet
355  * is connected to a 1G PHY. This function allows the MAC to indicate its
356  * maximum speed, and so limit what the PHY will advertise.
357  */
358 void phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
359 {
360 	__set_phy_supported(phydev, max_speed);
361 
362 	phy_advertise_supported(phydev);
363 }
364 EXPORT_SYMBOL(phy_set_max_speed);
365 
366 void of_set_phy_supported(struct phy_device *phydev)
367 {
368 	struct device_node *node = phydev->mdio.dev.of_node;
369 	u32 max_speed;
370 
371 	if (!IS_ENABLED(CONFIG_OF_MDIO))
372 		return;
373 
374 	if (!node)
375 		return;
376 
377 	if (!of_property_read_u32(node, "max-speed", &max_speed))
378 		__set_phy_supported(phydev, max_speed);
379 }
380 
381 void of_set_phy_eee_broken(struct phy_device *phydev)
382 {
383 	struct device_node *node = phydev->mdio.dev.of_node;
384 	u32 broken = 0;
385 
386 	if (!IS_ENABLED(CONFIG_OF_MDIO))
387 		return;
388 
389 	if (!node)
390 		return;
391 
392 	if (of_property_read_bool(node, "eee-broken-100tx"))
393 		broken |= MDIO_EEE_100TX;
394 	if (of_property_read_bool(node, "eee-broken-1000t"))
395 		broken |= MDIO_EEE_1000T;
396 	if (of_property_read_bool(node, "eee-broken-10gt"))
397 		broken |= MDIO_EEE_10GT;
398 	if (of_property_read_bool(node, "eee-broken-1000kx"))
399 		broken |= MDIO_EEE_1000KX;
400 	if (of_property_read_bool(node, "eee-broken-10gkx4"))
401 		broken |= MDIO_EEE_10GKX4;
402 	if (of_property_read_bool(node, "eee-broken-10gkr"))
403 		broken |= MDIO_EEE_10GKR;
404 
405 	phydev->eee_broken_modes = broken;
406 }
407 
408 /**
409  * phy_resolve_aneg_pause - Determine pause autoneg results
410  *
411  * @phydev: The phy_device struct
412  *
413  * Once autoneg has completed the local pause settings can be
414  * resolved.  Determine if pause and asymmetric pause should be used
415  * by the MAC.
416  */
417 
418 void phy_resolve_aneg_pause(struct phy_device *phydev)
419 {
420 	if (phydev->duplex == DUPLEX_FULL) {
421 		phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
422 						  phydev->lp_advertising);
423 		phydev->asym_pause = linkmode_test_bit(
424 			ETHTOOL_LINK_MODE_Asym_Pause_BIT,
425 			phydev->lp_advertising);
426 	}
427 }
428 EXPORT_SYMBOL_GPL(phy_resolve_aneg_pause);
429 
430 /**
431  * phy_resolve_aneg_linkmode - resolve the advertisements into PHY settings
432  * @phydev: The phy_device struct
433  *
434  * Resolve our and the link partner advertisements into their corresponding
435  * speed and duplex. If full duplex was negotiated, extract the pause mode
436  * from the link partner mask.
437  */
438 void phy_resolve_aneg_linkmode(struct phy_device *phydev)
439 {
440 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
441 	int i;
442 
443 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
444 
445 	for (i = 0; i < ARRAY_SIZE(settings); i++)
446 		if (test_bit(settings[i].bit, common)) {
447 			phydev->speed = settings[i].speed;
448 			phydev->duplex = settings[i].duplex;
449 			break;
450 		}
451 
452 	phy_resolve_aneg_pause(phydev);
453 }
454 EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
455 
456 /**
457  * phy_check_downshift - check whether downshift occurred
458  * @phydev: The phy_device struct
459  *
460  * Check whether a downshift to a lower speed occurred. If this should be the
461  * case warn the user.
462  * Prerequisite for detecting downshift is that PHY driver implements the
463  * read_status callback and sets phydev->speed to the actual link speed.
464  */
465 void phy_check_downshift(struct phy_device *phydev)
466 {
467 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
468 	int i, speed = SPEED_UNKNOWN;
469 
470 	phydev->downshifted_rate = 0;
471 
472 	if (phydev->autoneg == AUTONEG_DISABLE ||
473 	    phydev->speed == SPEED_UNKNOWN)
474 		return;
475 
476 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
477 
478 	for (i = 0; i < ARRAY_SIZE(settings); i++)
479 		if (test_bit(settings[i].bit, common)) {
480 			speed = settings[i].speed;
481 			break;
482 		}
483 
484 	if (speed == SPEED_UNKNOWN || phydev->speed >= speed)
485 		return;
486 
487 	phydev_warn(phydev, "Downshift occurred from negotiated speed %s to actual speed %s, check cabling!\n",
488 		    phy_speed_to_str(speed), phy_speed_to_str(phydev->speed));
489 
490 	phydev->downshifted_rate = 1;
491 }
492 EXPORT_SYMBOL_GPL(phy_check_downshift);
493 
494 static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
495 {
496 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
497 	int i = ARRAY_SIZE(settings);
498 
499 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
500 
501 	while (--i >= 0) {
502 		if (test_bit(settings[i].bit, common)) {
503 			if (fdx_only && settings[i].duplex != DUPLEX_FULL)
504 				continue;
505 			return settings[i].speed;
506 		}
507 	}
508 
509 	return SPEED_UNKNOWN;
510 }
511 
512 int phy_speed_down_core(struct phy_device *phydev)
513 {
514 	int min_common_speed = phy_resolve_min_speed(phydev, true);
515 
516 	if (min_common_speed == SPEED_UNKNOWN)
517 		return -EINVAL;
518 
519 	__set_linkmode_max_speed(min_common_speed, phydev->advertising);
520 
521 	return 0;
522 }
523 
524 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
525 			     u16 regnum)
526 {
527 	/* Write the desired MMD Devad */
528 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
529 
530 	/* Write the desired MMD register address */
531 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
532 
533 	/* Select the Function : DATA with no post increment */
534 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
535 			devad | MII_MMD_CTRL_NOINCR);
536 }
537 
538 /**
539  * __phy_read_mmd - Convenience function for reading a register
540  * from an MMD on a given PHY.
541  * @phydev: The phy_device struct
542  * @devad: The MMD to read from (0..31)
543  * @regnum: The register on the MMD to read (0..65535)
544  *
545  * Same rules as for __phy_read();
546  */
547 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
548 {
549 	int val;
550 
551 	if (regnum > (u16)~0 || devad > 32)
552 		return -EINVAL;
553 
554 	if (phydev->drv && phydev->drv->read_mmd) {
555 		val = phydev->drv->read_mmd(phydev, devad, regnum);
556 	} else if (phydev->is_c45) {
557 		val = __mdiobus_c45_read(phydev->mdio.bus, phydev->mdio.addr,
558 					 devad, regnum);
559 	} else {
560 		struct mii_bus *bus = phydev->mdio.bus;
561 		int phy_addr = phydev->mdio.addr;
562 
563 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
564 
565 		/* Read the content of the MMD's selected register */
566 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
567 	}
568 	return val;
569 }
570 EXPORT_SYMBOL(__phy_read_mmd);
571 
572 /**
573  * phy_read_mmd - Convenience function for reading a register
574  * from an MMD on a given PHY.
575  * @phydev: The phy_device struct
576  * @devad: The MMD to read from
577  * @regnum: The register on the MMD to read
578  *
579  * Same rules as for phy_read();
580  */
581 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
582 {
583 	int ret;
584 
585 	phy_lock_mdio_bus(phydev);
586 	ret = __phy_read_mmd(phydev, devad, regnum);
587 	phy_unlock_mdio_bus(phydev);
588 
589 	return ret;
590 }
591 EXPORT_SYMBOL(phy_read_mmd);
592 
593 /**
594  * __phy_write_mmd - Convenience function for writing a register
595  * on an MMD on a given PHY.
596  * @phydev: The phy_device struct
597  * @devad: The MMD to read from
598  * @regnum: The register on the MMD to read
599  * @val: value to write to @regnum
600  *
601  * Same rules as for __phy_write();
602  */
603 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
604 {
605 	int ret;
606 
607 	if (regnum > (u16)~0 || devad > 32)
608 		return -EINVAL;
609 
610 	if (phydev->drv && phydev->drv->write_mmd) {
611 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
612 	} else if (phydev->is_c45) {
613 		ret = __mdiobus_c45_write(phydev->mdio.bus, phydev->mdio.addr,
614 					  devad, regnum, val);
615 	} else {
616 		struct mii_bus *bus = phydev->mdio.bus;
617 		int phy_addr = phydev->mdio.addr;
618 
619 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
620 
621 		/* Write the data into MMD's selected register */
622 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
623 
624 		ret = 0;
625 	}
626 	return ret;
627 }
628 EXPORT_SYMBOL(__phy_write_mmd);
629 
630 /**
631  * phy_write_mmd - Convenience function for writing a register
632  * on an MMD on a given PHY.
633  * @phydev: The phy_device struct
634  * @devad: The MMD to read from
635  * @regnum: The register on the MMD to read
636  * @val: value to write to @regnum
637  *
638  * Same rules as for phy_write();
639  */
640 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
641 {
642 	int ret;
643 
644 	phy_lock_mdio_bus(phydev);
645 	ret = __phy_write_mmd(phydev, devad, regnum, val);
646 	phy_unlock_mdio_bus(phydev);
647 
648 	return ret;
649 }
650 EXPORT_SYMBOL(phy_write_mmd);
651 
652 /**
653  * phy_modify_changed - Function for modifying a PHY register
654  * @phydev: the phy_device struct
655  * @regnum: register number to modify
656  * @mask: bit mask of bits to clear
657  * @set: new value of bits set in mask to write to @regnum
658  *
659  * NOTE: MUST NOT be called from interrupt context,
660  * because the bus read/write functions may wait for an interrupt
661  * to conclude the operation.
662  *
663  * Returns negative errno, 0 if there was no change, and 1 in case of change
664  */
665 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
666 {
667 	int ret;
668 
669 	phy_lock_mdio_bus(phydev);
670 	ret = __phy_modify_changed(phydev, regnum, mask, set);
671 	phy_unlock_mdio_bus(phydev);
672 
673 	return ret;
674 }
675 EXPORT_SYMBOL_GPL(phy_modify_changed);
676 
677 /**
678  * __phy_modify - Convenience function for modifying a PHY register
679  * @phydev: the phy_device struct
680  * @regnum: register number to modify
681  * @mask: bit mask of bits to clear
682  * @set: new value of bits set in mask to write to @regnum
683  *
684  * NOTE: MUST NOT be called from interrupt context,
685  * because the bus read/write functions may wait for an interrupt
686  * to conclude the operation.
687  */
688 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
689 {
690 	int ret;
691 
692 	ret = __phy_modify_changed(phydev, regnum, mask, set);
693 
694 	return ret < 0 ? ret : 0;
695 }
696 EXPORT_SYMBOL_GPL(__phy_modify);
697 
698 /**
699  * phy_modify - Convenience function for modifying a given PHY register
700  * @phydev: the phy_device struct
701  * @regnum: register number to write
702  * @mask: bit mask of bits to clear
703  * @set: new value of bits set in mask to write to @regnum
704  *
705  * NOTE: MUST NOT be called from interrupt context,
706  * because the bus read/write functions may wait for an interrupt
707  * to conclude the operation.
708  */
709 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
710 {
711 	int ret;
712 
713 	phy_lock_mdio_bus(phydev);
714 	ret = __phy_modify(phydev, regnum, mask, set);
715 	phy_unlock_mdio_bus(phydev);
716 
717 	return ret;
718 }
719 EXPORT_SYMBOL_GPL(phy_modify);
720 
721 /**
722  * __phy_modify_mmd_changed - Function for modifying a register on MMD
723  * @phydev: the phy_device struct
724  * @devad: the MMD containing register to modify
725  * @regnum: register number to modify
726  * @mask: bit mask of bits to clear
727  * @set: new value of bits set in mask to write to @regnum
728  *
729  * Unlocked helper function which allows a MMD register to be modified as
730  * new register value = (old register value & ~mask) | set
731  *
732  * Returns negative errno, 0 if there was no change, and 1 in case of change
733  */
734 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
735 			     u16 mask, u16 set)
736 {
737 	int new, ret;
738 
739 	ret = __phy_read_mmd(phydev, devad, regnum);
740 	if (ret < 0)
741 		return ret;
742 
743 	new = (ret & ~mask) | set;
744 	if (new == ret)
745 		return 0;
746 
747 	ret = __phy_write_mmd(phydev, devad, regnum, new);
748 
749 	return ret < 0 ? ret : 1;
750 }
751 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
752 
753 /**
754  * phy_modify_mmd_changed - Function for modifying a register on MMD
755  * @phydev: the phy_device struct
756  * @devad: the MMD containing register to modify
757  * @regnum: register number to modify
758  * @mask: bit mask of bits to clear
759  * @set: new value of bits set in mask to write to @regnum
760  *
761  * NOTE: MUST NOT be called from interrupt context,
762  * because the bus read/write functions may wait for an interrupt
763  * to conclude the operation.
764  *
765  * Returns negative errno, 0 if there was no change, and 1 in case of change
766  */
767 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
768 			   u16 mask, u16 set)
769 {
770 	int ret;
771 
772 	phy_lock_mdio_bus(phydev);
773 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
774 	phy_unlock_mdio_bus(phydev);
775 
776 	return ret;
777 }
778 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
779 
780 /**
781  * __phy_modify_mmd - Convenience function for modifying a register on MMD
782  * @phydev: the phy_device struct
783  * @devad: the MMD containing register to modify
784  * @regnum: register number to modify
785  * @mask: bit mask of bits to clear
786  * @set: new value of bits set in mask to write to @regnum
787  *
788  * NOTE: MUST NOT be called from interrupt context,
789  * because the bus read/write functions may wait for an interrupt
790  * to conclude the operation.
791  */
792 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
793 		     u16 mask, u16 set)
794 {
795 	int ret;
796 
797 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
798 
799 	return ret < 0 ? ret : 0;
800 }
801 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
802 
803 /**
804  * phy_modify_mmd - Convenience function for modifying a register on MMD
805  * @phydev: the phy_device struct
806  * @devad: the MMD containing register to modify
807  * @regnum: register number to modify
808  * @mask: bit mask of bits to clear
809  * @set: new value of bits set in mask to write to @regnum
810  *
811  * NOTE: MUST NOT be called from interrupt context,
812  * because the bus read/write functions may wait for an interrupt
813  * to conclude the operation.
814  */
815 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
816 		   u16 mask, u16 set)
817 {
818 	int ret;
819 
820 	phy_lock_mdio_bus(phydev);
821 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
822 	phy_unlock_mdio_bus(phydev);
823 
824 	return ret;
825 }
826 EXPORT_SYMBOL_GPL(phy_modify_mmd);
827 
828 static int __phy_read_page(struct phy_device *phydev)
829 {
830 	if (WARN_ONCE(!phydev->drv->read_page, "read_page callback not available, PHY driver not loaded?\n"))
831 		return -EOPNOTSUPP;
832 
833 	return phydev->drv->read_page(phydev);
834 }
835 
836 static int __phy_write_page(struct phy_device *phydev, int page)
837 {
838 	if (WARN_ONCE(!phydev->drv->write_page, "write_page callback not available, PHY driver not loaded?\n"))
839 		return -EOPNOTSUPP;
840 
841 	return phydev->drv->write_page(phydev, page);
842 }
843 
844 /**
845  * phy_save_page() - take the bus lock and save the current page
846  * @phydev: a pointer to a &struct phy_device
847  *
848  * Take the MDIO bus lock, and return the current page number. On error,
849  * returns a negative errno. phy_restore_page() must always be called
850  * after this, irrespective of success or failure of this call.
851  */
852 int phy_save_page(struct phy_device *phydev)
853 {
854 	phy_lock_mdio_bus(phydev);
855 	return __phy_read_page(phydev);
856 }
857 EXPORT_SYMBOL_GPL(phy_save_page);
858 
859 /**
860  * phy_select_page() - take the bus lock, save the current page, and set a page
861  * @phydev: a pointer to a &struct phy_device
862  * @page: desired page
863  *
864  * Take the MDIO bus lock to protect against concurrent access, save the
865  * current PHY page, and set the current page.  On error, returns a
866  * negative errno, otherwise returns the previous page number.
867  * phy_restore_page() must always be called after this, irrespective
868  * of success or failure of this call.
869  */
870 int phy_select_page(struct phy_device *phydev, int page)
871 {
872 	int ret, oldpage;
873 
874 	oldpage = ret = phy_save_page(phydev);
875 	if (ret < 0)
876 		return ret;
877 
878 	if (oldpage != page) {
879 		ret = __phy_write_page(phydev, page);
880 		if (ret < 0)
881 			return ret;
882 	}
883 
884 	return oldpage;
885 }
886 EXPORT_SYMBOL_GPL(phy_select_page);
887 
888 /**
889  * phy_restore_page() - restore the page register and release the bus lock
890  * @phydev: a pointer to a &struct phy_device
891  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
892  * @ret: operation's return code
893  *
894  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
895  * This function propagates the earliest error code from the group of
896  * operations.
897  *
898  * Returns:
899  *   @oldpage if it was a negative value, otherwise
900  *   @ret if it was a negative errno value, otherwise
901  *   phy_write_page()'s negative value if it were in error, otherwise
902  *   @ret.
903  */
904 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
905 {
906 	int r;
907 
908 	if (oldpage >= 0) {
909 		r = __phy_write_page(phydev, oldpage);
910 
911 		/* Propagate the operation return code if the page write
912 		 * was successful.
913 		 */
914 		if (ret >= 0 && r < 0)
915 			ret = r;
916 	} else {
917 		/* Propagate the phy page selection error code */
918 		ret = oldpage;
919 	}
920 
921 	phy_unlock_mdio_bus(phydev);
922 
923 	return ret;
924 }
925 EXPORT_SYMBOL_GPL(phy_restore_page);
926 
927 /**
928  * phy_read_paged() - Convenience function for reading a paged register
929  * @phydev: a pointer to a &struct phy_device
930  * @page: the page for the phy
931  * @regnum: register number
932  *
933  * Same rules as for phy_read().
934  */
935 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
936 {
937 	int ret = 0, oldpage;
938 
939 	oldpage = phy_select_page(phydev, page);
940 	if (oldpage >= 0)
941 		ret = __phy_read(phydev, regnum);
942 
943 	return phy_restore_page(phydev, oldpage, ret);
944 }
945 EXPORT_SYMBOL(phy_read_paged);
946 
947 /**
948  * phy_write_paged() - Convenience function for writing a paged register
949  * @phydev: a pointer to a &struct phy_device
950  * @page: the page for the phy
951  * @regnum: register number
952  * @val: value to write
953  *
954  * Same rules as for phy_write().
955  */
956 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
957 {
958 	int ret = 0, oldpage;
959 
960 	oldpage = phy_select_page(phydev, page);
961 	if (oldpage >= 0)
962 		ret = __phy_write(phydev, regnum, val);
963 
964 	return phy_restore_page(phydev, oldpage, ret);
965 }
966 EXPORT_SYMBOL(phy_write_paged);
967 
968 /**
969  * phy_modify_paged_changed() - Function for modifying a paged register
970  * @phydev: a pointer to a &struct phy_device
971  * @page: the page for the phy
972  * @regnum: register number
973  * @mask: bit mask of bits to clear
974  * @set: bit mask of bits to set
975  *
976  * Returns negative errno, 0 if there was no change, and 1 in case of change
977  */
978 int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
979 			     u16 mask, u16 set)
980 {
981 	int ret = 0, oldpage;
982 
983 	oldpage = phy_select_page(phydev, page);
984 	if (oldpage >= 0)
985 		ret = __phy_modify_changed(phydev, regnum, mask, set);
986 
987 	return phy_restore_page(phydev, oldpage, ret);
988 }
989 EXPORT_SYMBOL(phy_modify_paged_changed);
990 
991 /**
992  * phy_modify_paged() - Convenience function for modifying a paged register
993  * @phydev: a pointer to a &struct phy_device
994  * @page: the page for the phy
995  * @regnum: register number
996  * @mask: bit mask of bits to clear
997  * @set: bit mask of bits to set
998  *
999  * Same rules as for phy_read() and phy_write().
1000  */
1001 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
1002 		     u16 mask, u16 set)
1003 {
1004 	int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);
1005 
1006 	return ret < 0 ? ret : 0;
1007 }
1008 EXPORT_SYMBOL(phy_modify_paged);
1009