xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision a20eefae)
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 const char *phy_speed_to_str(int speed)
10 {
11 	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 69,
12 		"Enum ethtool_link_mode_bit_indices and phylib are out of sync. "
13 		"If a speed or mode has been added please update phy_speed_to_str "
14 		"and the PHY settings array.\n");
15 
16 	switch (speed) {
17 	case SPEED_10:
18 		return "10Mbps";
19 	case SPEED_100:
20 		return "100Mbps";
21 	case SPEED_1000:
22 		return "1Gbps";
23 	case SPEED_2500:
24 		return "2.5Gbps";
25 	case SPEED_5000:
26 		return "5Gbps";
27 	case SPEED_10000:
28 		return "10Gbps";
29 	case SPEED_14000:
30 		return "14Gbps";
31 	case SPEED_20000:
32 		return "20Gbps";
33 	case SPEED_25000:
34 		return "25Gbps";
35 	case SPEED_40000:
36 		return "40Gbps";
37 	case SPEED_50000:
38 		return "50Gbps";
39 	case SPEED_56000:
40 		return "56Gbps";
41 	case SPEED_100000:
42 		return "100Gbps";
43 	case SPEED_200000:
44 		return "200Gbps";
45 	case SPEED_UNKNOWN:
46 		return "Unknown";
47 	default:
48 		return "Unsupported (update phy-core.c)";
49 	}
50 }
51 EXPORT_SYMBOL_GPL(phy_speed_to_str);
52 
53 const char *phy_duplex_to_str(unsigned int duplex)
54 {
55 	if (duplex == DUPLEX_HALF)
56 		return "Half";
57 	if (duplex == DUPLEX_FULL)
58 		return "Full";
59 	if (duplex == DUPLEX_UNKNOWN)
60 		return "Unknown";
61 	return "Unsupported (update phy-core.c)";
62 }
63 EXPORT_SYMBOL_GPL(phy_duplex_to_str);
64 
65 /* A mapping of all SUPPORTED settings to speed/duplex.  This table
66  * must be grouped by speed and sorted in descending match priority
67  * - iow, descending speed. */
68 
69 #define PHY_SETTING(s, d, b) { .speed = SPEED_ ## s, .duplex = DUPLEX_ ## d, \
70 			       .bit = ETHTOOL_LINK_MODE_ ## b ## _BIT}
71 
72 static const struct phy_setting settings[] = {
73 	/* 200G */
74 	PHY_SETTING( 200000, FULL, 200000baseCR4_Full		),
75 	PHY_SETTING( 200000, FULL, 200000baseKR4_Full		),
76 	PHY_SETTING( 200000, FULL, 200000baseLR4_ER4_FR4_Full	),
77 	PHY_SETTING( 200000, FULL, 200000baseDR4_Full		),
78 	PHY_SETTING( 200000, FULL, 200000baseSR4_Full		),
79 	/* 100G */
80 	PHY_SETTING( 100000, FULL, 100000baseCR4_Full		),
81 	PHY_SETTING( 100000, FULL, 100000baseKR4_Full		),
82 	PHY_SETTING( 100000, FULL, 100000baseLR4_ER4_Full	),
83 	PHY_SETTING( 100000, FULL, 100000baseSR4_Full		),
84 	PHY_SETTING( 100000, FULL, 100000baseCR2_Full		),
85 	PHY_SETTING( 100000, FULL, 100000baseKR2_Full		),
86 	PHY_SETTING( 100000, FULL, 100000baseLR2_ER2_FR2_Full	),
87 	PHY_SETTING( 100000, FULL, 100000baseDR2_Full		),
88 	PHY_SETTING( 100000, FULL, 100000baseSR2_Full		),
89 	/* 56G */
90 	PHY_SETTING(  56000, FULL,  56000baseCR4_Full	  	),
91 	PHY_SETTING(  56000, FULL,  56000baseKR4_Full	  	),
92 	PHY_SETTING(  56000, FULL,  56000baseLR4_Full	  	),
93 	PHY_SETTING(  56000, FULL,  56000baseSR4_Full	  	),
94 	/* 50G */
95 	PHY_SETTING(  50000, FULL,  50000baseCR2_Full		),
96 	PHY_SETTING(  50000, FULL,  50000baseKR2_Full		),
97 	PHY_SETTING(  50000, FULL,  50000baseSR2_Full		),
98 	PHY_SETTING(  50000, FULL,  50000baseCR_Full		),
99 	PHY_SETTING(  50000, FULL,  50000baseKR_Full		),
100 	PHY_SETTING(  50000, FULL,  50000baseLR_ER_FR_Full	),
101 	PHY_SETTING(  50000, FULL,  50000baseDR_Full		),
102 	PHY_SETTING(  50000, FULL,  50000baseSR_Full		),
103 	/* 40G */
104 	PHY_SETTING(  40000, FULL,  40000baseCR4_Full		),
105 	PHY_SETTING(  40000, FULL,  40000baseKR4_Full		),
106 	PHY_SETTING(  40000, FULL,  40000baseLR4_Full		),
107 	PHY_SETTING(  40000, FULL,  40000baseSR4_Full		),
108 	/* 25G */
109 	PHY_SETTING(  25000, FULL,  25000baseCR_Full		),
110 	PHY_SETTING(  25000, FULL,  25000baseKR_Full		),
111 	PHY_SETTING(  25000, FULL,  25000baseSR_Full		),
112 	/* 20G */
113 	PHY_SETTING(  20000, FULL,  20000baseKR2_Full		),
114 	PHY_SETTING(  20000, FULL,  20000baseMLD2_Full		),
115 	/* 10G */
116 	PHY_SETTING(  10000, FULL,  10000baseCR_Full		),
117 	PHY_SETTING(  10000, FULL,  10000baseER_Full		),
118 	PHY_SETTING(  10000, FULL,  10000baseKR_Full		),
119 	PHY_SETTING(  10000, FULL,  10000baseKX4_Full		),
120 	PHY_SETTING(  10000, FULL,  10000baseLR_Full		),
121 	PHY_SETTING(  10000, FULL,  10000baseLRM_Full		),
122 	PHY_SETTING(  10000, FULL,  10000baseR_FEC		),
123 	PHY_SETTING(  10000, FULL,  10000baseSR_Full		),
124 	PHY_SETTING(  10000, FULL,  10000baseT_Full		),
125 	/* 5G */
126 	PHY_SETTING(   5000, FULL,   5000baseT_Full		),
127 	/* 2.5G */
128 	PHY_SETTING(   2500, FULL,   2500baseT_Full		),
129 	PHY_SETTING(   2500, FULL,   2500baseX_Full		),
130 	/* 1G */
131 	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
132 	PHY_SETTING(   1000, FULL,   1000baseT_Full		),
133 	PHY_SETTING(   1000, HALF,   1000baseT_Half		),
134 	PHY_SETTING(   1000, FULL,   1000baseT1_Full		),
135 	PHY_SETTING(   1000, FULL,   1000baseX_Full		),
136 	/* 100M */
137 	PHY_SETTING(    100, FULL,    100baseT_Full		),
138 	PHY_SETTING(    100, FULL,    100baseT1_Full		),
139 	PHY_SETTING(    100, HALF,    100baseT_Half		),
140 	/* 10M */
141 	PHY_SETTING(     10, FULL,     10baseT_Full		),
142 	PHY_SETTING(     10, HALF,     10baseT_Half		),
143 };
144 #undef PHY_SETTING
145 
146 /**
147  * phy_lookup_setting - lookup a PHY setting
148  * @speed: speed to match
149  * @duplex: duplex to match
150  * @mask: allowed link modes
151  * @exact: an exact match is required
152  *
153  * Search the settings array for a setting that matches the speed and
154  * duplex, and which is supported.
155  *
156  * If @exact is unset, either an exact match or %NULL for no match will
157  * be returned.
158  *
159  * If @exact is set, an exact match, the fastest supported setting at
160  * or below the specified speed, the slowest supported setting, or if
161  * they all fail, %NULL will be returned.
162  */
163 const struct phy_setting *
164 phy_lookup_setting(int speed, int duplex, const unsigned long *mask, bool exact)
165 {
166 	const struct phy_setting *p, *match = NULL, *last = NULL;
167 	int i;
168 
169 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
170 		if (p->bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
171 		    test_bit(p->bit, mask)) {
172 			last = p;
173 			if (p->speed == speed && p->duplex == duplex) {
174 				/* Exact match for speed and duplex */
175 				match = p;
176 				break;
177 			} else if (!exact) {
178 				if (!match && p->speed <= speed)
179 					/* Candidate */
180 					match = p;
181 
182 				if (p->speed < speed)
183 					break;
184 			}
185 		}
186 	}
187 
188 	if (!match && !exact)
189 		match = last;
190 
191 	return match;
192 }
193 EXPORT_SYMBOL_GPL(phy_lookup_setting);
194 
195 size_t phy_speeds(unsigned int *speeds, size_t size,
196 		  unsigned long *mask)
197 {
198 	size_t count;
199 	int i;
200 
201 	for (i = 0, count = 0; i < ARRAY_SIZE(settings) && count < size; i++)
202 		if (settings[i].bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
203 		    test_bit(settings[i].bit, mask) &&
204 		    (count == 0 || speeds[count - 1] != settings[i].speed))
205 			speeds[count++] = settings[i].speed;
206 
207 	return count;
208 }
209 
210 static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
211 {
212 	const struct phy_setting *p;
213 	int i;
214 
215 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
216 		if (p->speed > max_speed)
217 			linkmode_clear_bit(p->bit, phydev->supported);
218 		else
219 			break;
220 	}
221 
222 	return 0;
223 }
224 
225 int phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
226 {
227 	int err;
228 
229 	err = __set_phy_supported(phydev, max_speed);
230 	if (err)
231 		return err;
232 
233 	phy_advertise_supported(phydev);
234 
235 	return 0;
236 }
237 EXPORT_SYMBOL(phy_set_max_speed);
238 
239 void of_set_phy_supported(struct phy_device *phydev)
240 {
241 	struct device_node *node = phydev->mdio.dev.of_node;
242 	u32 max_speed;
243 
244 	if (!IS_ENABLED(CONFIG_OF_MDIO))
245 		return;
246 
247 	if (!node)
248 		return;
249 
250 	if (!of_property_read_u32(node, "max-speed", &max_speed))
251 		__set_phy_supported(phydev, max_speed);
252 }
253 
254 void of_set_phy_eee_broken(struct phy_device *phydev)
255 {
256 	struct device_node *node = phydev->mdio.dev.of_node;
257 	u32 broken = 0;
258 
259 	if (!IS_ENABLED(CONFIG_OF_MDIO))
260 		return;
261 
262 	if (!node)
263 		return;
264 
265 	if (of_property_read_bool(node, "eee-broken-100tx"))
266 		broken |= MDIO_EEE_100TX;
267 	if (of_property_read_bool(node, "eee-broken-1000t"))
268 		broken |= MDIO_EEE_1000T;
269 	if (of_property_read_bool(node, "eee-broken-10gt"))
270 		broken |= MDIO_EEE_10GT;
271 	if (of_property_read_bool(node, "eee-broken-1000kx"))
272 		broken |= MDIO_EEE_1000KX;
273 	if (of_property_read_bool(node, "eee-broken-10gkx4"))
274 		broken |= MDIO_EEE_10GKX4;
275 	if (of_property_read_bool(node, "eee-broken-10gkr"))
276 		broken |= MDIO_EEE_10GKR;
277 
278 	phydev->eee_broken_modes = broken;
279 }
280 
281 /**
282  * phy_resolve_aneg_linkmode - resolve the advertisements into phy settings
283  * @phydev: The phy_device struct
284  *
285  * Resolve our and the link partner advertisements into their corresponding
286  * speed and duplex. If full duplex was negotiated, extract the pause mode
287  * from the link partner mask.
288  */
289 void phy_resolve_aneg_linkmode(struct phy_device *phydev)
290 {
291 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
292 	int i;
293 
294 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
295 
296 	for (i = 0; i < ARRAY_SIZE(settings); i++)
297 		if (test_bit(settings[i].bit, common)) {
298 			phydev->speed = settings[i].speed;
299 			phydev->duplex = settings[i].duplex;
300 			break;
301 		}
302 
303 	if (phydev->duplex == DUPLEX_FULL) {
304 		phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
305 						  phydev->lp_advertising);
306 		phydev->asym_pause = linkmode_test_bit(
307 			ETHTOOL_LINK_MODE_Asym_Pause_BIT,
308 			phydev->lp_advertising);
309 	}
310 }
311 EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
312 
313 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
314 			     u16 regnum)
315 {
316 	/* Write the desired MMD Devad */
317 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
318 
319 	/* Write the desired MMD register address */
320 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
321 
322 	/* Select the Function : DATA with no post increment */
323 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
324 			devad | MII_MMD_CTRL_NOINCR);
325 }
326 
327 /**
328  * __phy_read_mmd - Convenience function for reading a register
329  * from an MMD on a given PHY.
330  * @phydev: The phy_device struct
331  * @devad: The MMD to read from (0..31)
332  * @regnum: The register on the MMD to read (0..65535)
333  *
334  * Same rules as for __phy_read();
335  */
336 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
337 {
338 	int val;
339 
340 	if (regnum > (u16)~0 || devad > 32)
341 		return -EINVAL;
342 
343 	if (phydev->drv->read_mmd) {
344 		val = phydev->drv->read_mmd(phydev, devad, regnum);
345 	} else if (phydev->is_c45) {
346 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
347 
348 		val = __mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, addr);
349 	} else {
350 		struct mii_bus *bus = phydev->mdio.bus;
351 		int phy_addr = phydev->mdio.addr;
352 
353 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
354 
355 		/* Read the content of the MMD's selected register */
356 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
357 	}
358 	return val;
359 }
360 EXPORT_SYMBOL(__phy_read_mmd);
361 
362 /**
363  * phy_read_mmd - Convenience function for reading a register
364  * from an MMD on a given PHY.
365  * @phydev: The phy_device struct
366  * @devad: The MMD to read from
367  * @regnum: The register on the MMD to read
368  *
369  * Same rules as for phy_read();
370  */
371 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
372 {
373 	int ret;
374 
375 	mutex_lock(&phydev->mdio.bus->mdio_lock);
376 	ret = __phy_read_mmd(phydev, devad, regnum);
377 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
378 
379 	return ret;
380 }
381 EXPORT_SYMBOL(phy_read_mmd);
382 
383 /**
384  * __phy_write_mmd - Convenience function for writing a register
385  * on an MMD on a given PHY.
386  * @phydev: The phy_device struct
387  * @devad: The MMD to read from
388  * @regnum: The register on the MMD to read
389  * @val: value to write to @regnum
390  *
391  * Same rules as for __phy_write();
392  */
393 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
394 {
395 	int ret;
396 
397 	if (regnum > (u16)~0 || devad > 32)
398 		return -EINVAL;
399 
400 	if (phydev->drv->write_mmd) {
401 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
402 	} else if (phydev->is_c45) {
403 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
404 
405 		ret = __mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
406 				      addr, val);
407 	} else {
408 		struct mii_bus *bus = phydev->mdio.bus;
409 		int phy_addr = phydev->mdio.addr;
410 
411 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
412 
413 		/* Write the data into MMD's selected register */
414 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
415 
416 		ret = 0;
417 	}
418 	return ret;
419 }
420 EXPORT_SYMBOL(__phy_write_mmd);
421 
422 /**
423  * phy_write_mmd - Convenience function for writing a register
424  * on an MMD on a given PHY.
425  * @phydev: The phy_device struct
426  * @devad: The MMD to read from
427  * @regnum: The register on the MMD to read
428  * @val: value to write to @regnum
429  *
430  * Same rules as for phy_write();
431  */
432 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
433 {
434 	int ret;
435 
436 	mutex_lock(&phydev->mdio.bus->mdio_lock);
437 	ret = __phy_write_mmd(phydev, devad, regnum, val);
438 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
439 
440 	return ret;
441 }
442 EXPORT_SYMBOL(phy_write_mmd);
443 
444 /**
445  * __phy_modify_changed() - Convenience function for modifying a PHY register
446  * @phydev: a pointer to a &struct phy_device
447  * @regnum: register number
448  * @mask: bit mask of bits to clear
449  * @set: bit mask of bits to set
450  *
451  * Unlocked helper function which allows a PHY register to be modified as
452  * new register value = (old register value & ~mask) | set
453  *
454  * Returns negative errno, 0 if there was no change, and 1 in case of change
455  */
456 int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
457 			 u16 set)
458 {
459 	int new, ret;
460 
461 	ret = __phy_read(phydev, regnum);
462 	if (ret < 0)
463 		return ret;
464 
465 	new = (ret & ~mask) | set;
466 	if (new == ret)
467 		return 0;
468 
469 	ret = __phy_write(phydev, regnum, new);
470 
471 	return ret < 0 ? ret : 1;
472 }
473 EXPORT_SYMBOL_GPL(__phy_modify_changed);
474 
475 /**
476  * phy_modify_changed - Function for modifying a PHY register
477  * @phydev: the phy_device struct
478  * @regnum: register number to modify
479  * @mask: bit mask of bits to clear
480  * @set: new value of bits set in mask to write to @regnum
481  *
482  * NOTE: MUST NOT be called from interrupt context,
483  * because the bus read/write functions may wait for an interrupt
484  * to conclude the operation.
485  *
486  * Returns negative errno, 0 if there was no change, and 1 in case of change
487  */
488 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
489 {
490 	int ret;
491 
492 	mutex_lock(&phydev->mdio.bus->mdio_lock);
493 	ret = __phy_modify_changed(phydev, regnum, mask, set);
494 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
495 
496 	return ret;
497 }
498 EXPORT_SYMBOL_GPL(phy_modify_changed);
499 
500 /**
501  * __phy_modify - Convenience function for modifying a PHY register
502  * @phydev: the phy_device struct
503  * @regnum: register number to modify
504  * @mask: bit mask of bits to clear
505  * @set: new value of bits set in mask to write to @regnum
506  *
507  * NOTE: MUST NOT be called from interrupt context,
508  * because the bus read/write functions may wait for an interrupt
509  * to conclude the operation.
510  */
511 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
512 {
513 	int ret;
514 
515 	ret = __phy_modify_changed(phydev, regnum, mask, set);
516 
517 	return ret < 0 ? ret : 0;
518 }
519 EXPORT_SYMBOL_GPL(__phy_modify);
520 
521 /**
522  * phy_modify - Convenience function for modifying a given PHY register
523  * @phydev: the phy_device struct
524  * @regnum: register number to write
525  * @mask: bit mask of bits to clear
526  * @set: new value of bits set in mask to write to @regnum
527  *
528  * NOTE: MUST NOT be called from interrupt context,
529  * because the bus read/write functions may wait for an interrupt
530  * to conclude the operation.
531  */
532 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
533 {
534 	int ret;
535 
536 	mutex_lock(&phydev->mdio.bus->mdio_lock);
537 	ret = __phy_modify(phydev, regnum, mask, set);
538 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
539 
540 	return ret;
541 }
542 EXPORT_SYMBOL_GPL(phy_modify);
543 
544 /**
545  * __phy_modify_mmd_changed - Function for modifying a register on MMD
546  * @phydev: the phy_device struct
547  * @devad: the MMD containing register to modify
548  * @regnum: register number to modify
549  * @mask: bit mask of bits to clear
550  * @set: new value of bits set in mask to write to @regnum
551  *
552  * Unlocked helper function which allows a MMD register to be modified as
553  * new register value = (old register value & ~mask) | set
554  *
555  * Returns negative errno, 0 if there was no change, and 1 in case of change
556  */
557 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
558 			     u16 mask, u16 set)
559 {
560 	int new, ret;
561 
562 	ret = __phy_read_mmd(phydev, devad, regnum);
563 	if (ret < 0)
564 		return ret;
565 
566 	new = (ret & ~mask) | set;
567 	if (new == ret)
568 		return 0;
569 
570 	ret = __phy_write_mmd(phydev, devad, regnum, new);
571 
572 	return ret < 0 ? ret : 1;
573 }
574 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
575 
576 /**
577  * phy_modify_mmd_changed - Function for modifying a register on MMD
578  * @phydev: the phy_device struct
579  * @devad: the MMD containing register to modify
580  * @regnum: register number to modify
581  * @mask: bit mask of bits to clear
582  * @set: new value of bits set in mask to write to @regnum
583  *
584  * NOTE: MUST NOT be called from interrupt context,
585  * because the bus read/write functions may wait for an interrupt
586  * to conclude the operation.
587  *
588  * Returns negative errno, 0 if there was no change, and 1 in case of change
589  */
590 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
591 			   u16 mask, u16 set)
592 {
593 	int ret;
594 
595 	mutex_lock(&phydev->mdio.bus->mdio_lock);
596 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
597 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
598 
599 	return ret;
600 }
601 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
602 
603 /**
604  * __phy_modify_mmd - Convenience function for modifying a register on MMD
605  * @phydev: the phy_device struct
606  * @devad: the MMD containing register to modify
607  * @regnum: register number to modify
608  * @mask: bit mask of bits to clear
609  * @set: new value of bits set in mask to write to @regnum
610  *
611  * NOTE: MUST NOT be called from interrupt context,
612  * because the bus read/write functions may wait for an interrupt
613  * to conclude the operation.
614  */
615 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
616 		     u16 mask, u16 set)
617 {
618 	int ret;
619 
620 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
621 
622 	return ret < 0 ? ret : 0;
623 }
624 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
625 
626 /**
627  * phy_modify_mmd - Convenience function for modifying a register on MMD
628  * @phydev: the phy_device struct
629  * @devad: the MMD containing register to modify
630  * @regnum: register number to modify
631  * @mask: bit mask of bits to clear
632  * @set: new value of bits set in mask to write to @regnum
633  *
634  * NOTE: MUST NOT be called from interrupt context,
635  * because the bus read/write functions may wait for an interrupt
636  * to conclude the operation.
637  */
638 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
639 		   u16 mask, u16 set)
640 {
641 	int ret;
642 
643 	mutex_lock(&phydev->mdio.bus->mdio_lock);
644 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
645 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
646 
647 	return ret;
648 }
649 EXPORT_SYMBOL_GPL(phy_modify_mmd);
650 
651 static int __phy_read_page(struct phy_device *phydev)
652 {
653 	return phydev->drv->read_page(phydev);
654 }
655 
656 static int __phy_write_page(struct phy_device *phydev, int page)
657 {
658 	return phydev->drv->write_page(phydev, page);
659 }
660 
661 /**
662  * phy_save_page() - take the bus lock and save the current page
663  * @phydev: a pointer to a &struct phy_device
664  *
665  * Take the MDIO bus lock, and return the current page number. On error,
666  * returns a negative errno. phy_restore_page() must always be called
667  * after this, irrespective of success or failure of this call.
668  */
669 int phy_save_page(struct phy_device *phydev)
670 {
671 	mutex_lock(&phydev->mdio.bus->mdio_lock);
672 	return __phy_read_page(phydev);
673 }
674 EXPORT_SYMBOL_GPL(phy_save_page);
675 
676 /**
677  * phy_select_page() - take the bus lock, save the current page, and set a page
678  * @phydev: a pointer to a &struct phy_device
679  * @page: desired page
680  *
681  * Take the MDIO bus lock to protect against concurrent access, save the
682  * current PHY page, and set the current page.  On error, returns a
683  * negative errno, otherwise returns the previous page number.
684  * phy_restore_page() must always be called after this, irrespective
685  * of success or failure of this call.
686  */
687 int phy_select_page(struct phy_device *phydev, int page)
688 {
689 	int ret, oldpage;
690 
691 	oldpage = ret = phy_save_page(phydev);
692 	if (ret < 0)
693 		return ret;
694 
695 	if (oldpage != page) {
696 		ret = __phy_write_page(phydev, page);
697 		if (ret < 0)
698 			return ret;
699 	}
700 
701 	return oldpage;
702 }
703 EXPORT_SYMBOL_GPL(phy_select_page);
704 
705 /**
706  * phy_restore_page() - restore the page register and release the bus lock
707  * @phydev: a pointer to a &struct phy_device
708  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
709  * @ret: operation's return code
710  *
711  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
712  * This function propagates the earliest error code from the group of
713  * operations.
714  *
715  * Returns:
716  *   @oldpage if it was a negative value, otherwise
717  *   @ret if it was a negative errno value, otherwise
718  *   phy_write_page()'s negative value if it were in error, otherwise
719  *   @ret.
720  */
721 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
722 {
723 	int r;
724 
725 	if (oldpage >= 0) {
726 		r = __phy_write_page(phydev, oldpage);
727 
728 		/* Propagate the operation return code if the page write
729 		 * was successful.
730 		 */
731 		if (ret >= 0 && r < 0)
732 			ret = r;
733 	} else {
734 		/* Propagate the phy page selection error code */
735 		ret = oldpage;
736 	}
737 
738 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
739 
740 	return ret;
741 }
742 EXPORT_SYMBOL_GPL(phy_restore_page);
743 
744 /**
745  * phy_read_paged() - Convenience function for reading a paged register
746  * @phydev: a pointer to a &struct phy_device
747  * @page: the page for the phy
748  * @regnum: register number
749  *
750  * Same rules as for phy_read().
751  */
752 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
753 {
754 	int ret = 0, oldpage;
755 
756 	oldpage = phy_select_page(phydev, page);
757 	if (oldpage >= 0)
758 		ret = __phy_read(phydev, regnum);
759 
760 	return phy_restore_page(phydev, oldpage, ret);
761 }
762 EXPORT_SYMBOL(phy_read_paged);
763 
764 /**
765  * phy_write_paged() - Convenience function for writing a paged register
766  * @phydev: a pointer to a &struct phy_device
767  * @page: the page for the phy
768  * @regnum: register number
769  * @val: value to write
770  *
771  * Same rules as for phy_write().
772  */
773 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
774 {
775 	int ret = 0, oldpage;
776 
777 	oldpage = phy_select_page(phydev, page);
778 	if (oldpage >= 0)
779 		ret = __phy_write(phydev, regnum, val);
780 
781 	return phy_restore_page(phydev, oldpage, ret);
782 }
783 EXPORT_SYMBOL(phy_write_paged);
784 
785 /**
786  * phy_modify_paged() - Convenience function for modifying a paged register
787  * @phydev: a pointer to a &struct phy_device
788  * @page: the page for the phy
789  * @regnum: register number
790  * @mask: bit mask of bits to clear
791  * @set: bit mask of bits to set
792  *
793  * Same rules as for phy_read() and phy_write().
794  */
795 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
796 		     u16 mask, u16 set)
797 {
798 	int ret = 0, oldpage;
799 
800 	oldpage = phy_select_page(phydev, page);
801 	if (oldpage >= 0)
802 		ret = __phy_modify(phydev, regnum, mask, set);
803 
804 	return phy_restore_page(phydev, oldpage, ret);
805 }
806 EXPORT_SYMBOL(phy_modify_paged);
807