xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision d9e32672)
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_linkmode_max_speed(u32 max_speed, unsigned long *addr)
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, addr);
218 		else
219 			break;
220 	}
221 
222 	return 0;
223 }
224 
225 static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
226 {
227 	return __set_linkmode_max_speed(max_speed, phydev->supported);
228 }
229 
230 int phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
231 {
232 	int err;
233 
234 	err = __set_phy_supported(phydev, max_speed);
235 	if (err)
236 		return err;
237 
238 	phy_advertise_supported(phydev);
239 
240 	return 0;
241 }
242 EXPORT_SYMBOL(phy_set_max_speed);
243 
244 void of_set_phy_supported(struct phy_device *phydev)
245 {
246 	struct device_node *node = phydev->mdio.dev.of_node;
247 	u32 max_speed;
248 
249 	if (!IS_ENABLED(CONFIG_OF_MDIO))
250 		return;
251 
252 	if (!node)
253 		return;
254 
255 	if (!of_property_read_u32(node, "max-speed", &max_speed))
256 		__set_phy_supported(phydev, max_speed);
257 }
258 
259 void of_set_phy_eee_broken(struct phy_device *phydev)
260 {
261 	struct device_node *node = phydev->mdio.dev.of_node;
262 	u32 broken = 0;
263 
264 	if (!IS_ENABLED(CONFIG_OF_MDIO))
265 		return;
266 
267 	if (!node)
268 		return;
269 
270 	if (of_property_read_bool(node, "eee-broken-100tx"))
271 		broken |= MDIO_EEE_100TX;
272 	if (of_property_read_bool(node, "eee-broken-1000t"))
273 		broken |= MDIO_EEE_1000T;
274 	if (of_property_read_bool(node, "eee-broken-10gt"))
275 		broken |= MDIO_EEE_10GT;
276 	if (of_property_read_bool(node, "eee-broken-1000kx"))
277 		broken |= MDIO_EEE_1000KX;
278 	if (of_property_read_bool(node, "eee-broken-10gkx4"))
279 		broken |= MDIO_EEE_10GKX4;
280 	if (of_property_read_bool(node, "eee-broken-10gkr"))
281 		broken |= MDIO_EEE_10GKR;
282 
283 	phydev->eee_broken_modes = broken;
284 }
285 
286 void phy_resolve_aneg_pause(struct phy_device *phydev)
287 {
288 	if (phydev->duplex == DUPLEX_FULL) {
289 		phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
290 						  phydev->lp_advertising);
291 		phydev->asym_pause = linkmode_test_bit(
292 			ETHTOOL_LINK_MODE_Asym_Pause_BIT,
293 			phydev->lp_advertising);
294 	}
295 }
296 EXPORT_SYMBOL_GPL(phy_resolve_aneg_pause);
297 
298 /**
299  * phy_resolve_aneg_linkmode - resolve the advertisements into phy settings
300  * @phydev: The phy_device struct
301  *
302  * Resolve our and the link partner advertisements into their corresponding
303  * speed and duplex. If full duplex was negotiated, extract the pause mode
304  * from the link partner mask.
305  */
306 void phy_resolve_aneg_linkmode(struct phy_device *phydev)
307 {
308 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
309 	int i;
310 
311 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
312 
313 	for (i = 0; i < ARRAY_SIZE(settings); i++)
314 		if (test_bit(settings[i].bit, common)) {
315 			phydev->speed = settings[i].speed;
316 			phydev->duplex = settings[i].duplex;
317 			break;
318 		}
319 
320 	phy_resolve_aneg_pause(phydev);
321 }
322 EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
323 
324 static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
325 {
326 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
327 	int i = ARRAY_SIZE(settings);
328 
329 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
330 
331 	while (--i >= 0) {
332 		if (test_bit(settings[i].bit, common)) {
333 			if (fdx_only && settings[i].duplex != DUPLEX_FULL)
334 				continue;
335 			return settings[i].speed;
336 		}
337 	}
338 
339 	return SPEED_UNKNOWN;
340 }
341 
342 int phy_speed_down_core(struct phy_device *phydev)
343 {
344 	int min_common_speed = phy_resolve_min_speed(phydev, true);
345 
346 	if (min_common_speed == SPEED_UNKNOWN)
347 		return -EINVAL;
348 
349 	return __set_linkmode_max_speed(min_common_speed, phydev->advertising);
350 }
351 
352 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
353 			     u16 regnum)
354 {
355 	/* Write the desired MMD Devad */
356 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
357 
358 	/* Write the desired MMD register address */
359 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
360 
361 	/* Select the Function : DATA with no post increment */
362 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
363 			devad | MII_MMD_CTRL_NOINCR);
364 }
365 
366 /**
367  * __phy_read_mmd - Convenience function for reading a register
368  * from an MMD on a given PHY.
369  * @phydev: The phy_device struct
370  * @devad: The MMD to read from (0..31)
371  * @regnum: The register on the MMD to read (0..65535)
372  *
373  * Same rules as for __phy_read();
374  */
375 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
376 {
377 	int val;
378 
379 	if (regnum > (u16)~0 || devad > 32)
380 		return -EINVAL;
381 
382 	if (phydev->drv->read_mmd) {
383 		val = phydev->drv->read_mmd(phydev, devad, regnum);
384 	} else if (phydev->is_c45) {
385 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
386 
387 		val = __mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, addr);
388 	} else {
389 		struct mii_bus *bus = phydev->mdio.bus;
390 		int phy_addr = phydev->mdio.addr;
391 
392 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
393 
394 		/* Read the content of the MMD's selected register */
395 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
396 	}
397 	return val;
398 }
399 EXPORT_SYMBOL(__phy_read_mmd);
400 
401 /**
402  * phy_read_mmd - Convenience function for reading a register
403  * from an MMD on a given PHY.
404  * @phydev: The phy_device struct
405  * @devad: The MMD to read from
406  * @regnum: The register on the MMD to read
407  *
408  * Same rules as for phy_read();
409  */
410 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
411 {
412 	int ret;
413 
414 	mutex_lock(&phydev->mdio.bus->mdio_lock);
415 	ret = __phy_read_mmd(phydev, devad, regnum);
416 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
417 
418 	return ret;
419 }
420 EXPORT_SYMBOL(phy_read_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 	if (regnum > (u16)~0 || devad > 32)
437 		return -EINVAL;
438 
439 	if (phydev->drv->write_mmd) {
440 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
441 	} else if (phydev->is_c45) {
442 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
443 
444 		ret = __mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
445 				      addr, val);
446 	} else {
447 		struct mii_bus *bus = phydev->mdio.bus;
448 		int phy_addr = phydev->mdio.addr;
449 
450 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
451 
452 		/* Write the data into MMD's selected register */
453 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
454 
455 		ret = 0;
456 	}
457 	return ret;
458 }
459 EXPORT_SYMBOL(__phy_write_mmd);
460 
461 /**
462  * phy_write_mmd - Convenience function for writing a register
463  * on an MMD on a given PHY.
464  * @phydev: The phy_device struct
465  * @devad: The MMD to read from
466  * @regnum: The register on the MMD to read
467  * @val: value to write to @regnum
468  *
469  * Same rules as for phy_write();
470  */
471 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
472 {
473 	int ret;
474 
475 	mutex_lock(&phydev->mdio.bus->mdio_lock);
476 	ret = __phy_write_mmd(phydev, devad, regnum, val);
477 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
478 
479 	return ret;
480 }
481 EXPORT_SYMBOL(phy_write_mmd);
482 
483 /**
484  * __phy_modify_changed() - Convenience function for modifying a PHY register
485  * @phydev: a pointer to a &struct phy_device
486  * @regnum: register number
487  * @mask: bit mask of bits to clear
488  * @set: bit mask of bits to set
489  *
490  * Unlocked helper function which allows a PHY register to be modified as
491  * new register value = (old register value & ~mask) | set
492  *
493  * Returns negative errno, 0 if there was no change, and 1 in case of change
494  */
495 int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
496 			 u16 set)
497 {
498 	int new, ret;
499 
500 	ret = __phy_read(phydev, regnum);
501 	if (ret < 0)
502 		return ret;
503 
504 	new = (ret & ~mask) | set;
505 	if (new == ret)
506 		return 0;
507 
508 	ret = __phy_write(phydev, regnum, new);
509 
510 	return ret < 0 ? ret : 1;
511 }
512 EXPORT_SYMBOL_GPL(__phy_modify_changed);
513 
514 /**
515  * phy_modify_changed - Function for modifying a PHY register
516  * @phydev: the phy_device struct
517  * @regnum: register number to modify
518  * @mask: bit mask of bits to clear
519  * @set: new value of bits set in mask to write to @regnum
520  *
521  * NOTE: MUST NOT be called from interrupt context,
522  * because the bus read/write functions may wait for an interrupt
523  * to conclude the operation.
524  *
525  * Returns negative errno, 0 if there was no change, and 1 in case of change
526  */
527 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
528 {
529 	int ret;
530 
531 	mutex_lock(&phydev->mdio.bus->mdio_lock);
532 	ret = __phy_modify_changed(phydev, regnum, mask, set);
533 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
534 
535 	return ret;
536 }
537 EXPORT_SYMBOL_GPL(phy_modify_changed);
538 
539 /**
540  * __phy_modify - Convenience function for modifying a PHY register
541  * @phydev: the phy_device struct
542  * @regnum: register number to modify
543  * @mask: bit mask of bits to clear
544  * @set: new value of bits set in mask to write to @regnum
545  *
546  * NOTE: MUST NOT be called from interrupt context,
547  * because the bus read/write functions may wait for an interrupt
548  * to conclude the operation.
549  */
550 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
551 {
552 	int ret;
553 
554 	ret = __phy_modify_changed(phydev, regnum, mask, set);
555 
556 	return ret < 0 ? ret : 0;
557 }
558 EXPORT_SYMBOL_GPL(__phy_modify);
559 
560 /**
561  * phy_modify - Convenience function for modifying a given PHY register
562  * @phydev: the phy_device struct
563  * @regnum: register number to write
564  * @mask: bit mask of bits to clear
565  * @set: new value of bits set in mask to write to @regnum
566  *
567  * NOTE: MUST NOT be called from interrupt context,
568  * because the bus read/write functions may wait for an interrupt
569  * to conclude the operation.
570  */
571 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
572 {
573 	int ret;
574 
575 	mutex_lock(&phydev->mdio.bus->mdio_lock);
576 	ret = __phy_modify(phydev, regnum, mask, set);
577 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
578 
579 	return ret;
580 }
581 EXPORT_SYMBOL_GPL(phy_modify);
582 
583 /**
584  * __phy_modify_mmd_changed - Function for modifying a register on MMD
585  * @phydev: the phy_device struct
586  * @devad: the MMD containing register to modify
587  * @regnum: register number to modify
588  * @mask: bit mask of bits to clear
589  * @set: new value of bits set in mask to write to @regnum
590  *
591  * Unlocked helper function which allows a MMD register to be modified as
592  * new register value = (old register value & ~mask) | set
593  *
594  * Returns negative errno, 0 if there was no change, and 1 in case of change
595  */
596 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
597 			     u16 mask, u16 set)
598 {
599 	int new, ret;
600 
601 	ret = __phy_read_mmd(phydev, devad, regnum);
602 	if (ret < 0)
603 		return ret;
604 
605 	new = (ret & ~mask) | set;
606 	if (new == ret)
607 		return 0;
608 
609 	ret = __phy_write_mmd(phydev, devad, regnum, new);
610 
611 	return ret < 0 ? ret : 1;
612 }
613 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
614 
615 /**
616  * phy_modify_mmd_changed - Function for modifying a register on MMD
617  * @phydev: the phy_device struct
618  * @devad: the MMD containing register to modify
619  * @regnum: register number to modify
620  * @mask: bit mask of bits to clear
621  * @set: new value of bits set in mask to write to @regnum
622  *
623  * NOTE: MUST NOT be called from interrupt context,
624  * because the bus read/write functions may wait for an interrupt
625  * to conclude the operation.
626  *
627  * Returns negative errno, 0 if there was no change, and 1 in case of change
628  */
629 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
630 			   u16 mask, u16 set)
631 {
632 	int ret;
633 
634 	mutex_lock(&phydev->mdio.bus->mdio_lock);
635 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
636 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
637 
638 	return ret;
639 }
640 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
641 
642 /**
643  * __phy_modify_mmd - Convenience function for modifying a register on MMD
644  * @phydev: the phy_device struct
645  * @devad: the MMD containing register to modify
646  * @regnum: register number to modify
647  * @mask: bit mask of bits to clear
648  * @set: new value of bits set in mask to write to @regnum
649  *
650  * NOTE: MUST NOT be called from interrupt context,
651  * because the bus read/write functions may wait for an interrupt
652  * to conclude the operation.
653  */
654 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
655 		     u16 mask, u16 set)
656 {
657 	int ret;
658 
659 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
660 
661 	return ret < 0 ? ret : 0;
662 }
663 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
664 
665 /**
666  * phy_modify_mmd - Convenience function for modifying a register on MMD
667  * @phydev: the phy_device struct
668  * @devad: the MMD containing register to modify
669  * @regnum: register number to modify
670  * @mask: bit mask of bits to clear
671  * @set: new value of bits set in mask to write to @regnum
672  *
673  * NOTE: MUST NOT be called from interrupt context,
674  * because the bus read/write functions may wait for an interrupt
675  * to conclude the operation.
676  */
677 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
678 		   u16 mask, u16 set)
679 {
680 	int ret;
681 
682 	mutex_lock(&phydev->mdio.bus->mdio_lock);
683 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
684 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
685 
686 	return ret;
687 }
688 EXPORT_SYMBOL_GPL(phy_modify_mmd);
689 
690 static int __phy_read_page(struct phy_device *phydev)
691 {
692 	return phydev->drv->read_page(phydev);
693 }
694 
695 static int __phy_write_page(struct phy_device *phydev, int page)
696 {
697 	return phydev->drv->write_page(phydev, page);
698 }
699 
700 /**
701  * phy_save_page() - take the bus lock and save the current page
702  * @phydev: a pointer to a &struct phy_device
703  *
704  * Take the MDIO bus lock, and return the current page number. On error,
705  * returns a negative errno. phy_restore_page() must always be called
706  * after this, irrespective of success or failure of this call.
707  */
708 int phy_save_page(struct phy_device *phydev)
709 {
710 	mutex_lock(&phydev->mdio.bus->mdio_lock);
711 	return __phy_read_page(phydev);
712 }
713 EXPORT_SYMBOL_GPL(phy_save_page);
714 
715 /**
716  * phy_select_page() - take the bus lock, save the current page, and set a page
717  * @phydev: a pointer to a &struct phy_device
718  * @page: desired page
719  *
720  * Take the MDIO bus lock to protect against concurrent access, save the
721  * current PHY page, and set the current page.  On error, returns a
722  * negative errno, otherwise returns the previous page number.
723  * phy_restore_page() must always be called after this, irrespective
724  * of success or failure of this call.
725  */
726 int phy_select_page(struct phy_device *phydev, int page)
727 {
728 	int ret, oldpage;
729 
730 	oldpage = ret = phy_save_page(phydev);
731 	if (ret < 0)
732 		return ret;
733 
734 	if (oldpage != page) {
735 		ret = __phy_write_page(phydev, page);
736 		if (ret < 0)
737 			return ret;
738 	}
739 
740 	return oldpage;
741 }
742 EXPORT_SYMBOL_GPL(phy_select_page);
743 
744 /**
745  * phy_restore_page() - restore the page register and release the bus lock
746  * @phydev: a pointer to a &struct phy_device
747  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
748  * @ret: operation's return code
749  *
750  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
751  * This function propagates the earliest error code from the group of
752  * operations.
753  *
754  * Returns:
755  *   @oldpage if it was a negative value, otherwise
756  *   @ret if it was a negative errno value, otherwise
757  *   phy_write_page()'s negative value if it were in error, otherwise
758  *   @ret.
759  */
760 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
761 {
762 	int r;
763 
764 	if (oldpage >= 0) {
765 		r = __phy_write_page(phydev, oldpage);
766 
767 		/* Propagate the operation return code if the page write
768 		 * was successful.
769 		 */
770 		if (ret >= 0 && r < 0)
771 			ret = r;
772 	} else {
773 		/* Propagate the phy page selection error code */
774 		ret = oldpage;
775 	}
776 
777 	mutex_unlock(&phydev->mdio.bus->mdio_lock);
778 
779 	return ret;
780 }
781 EXPORT_SYMBOL_GPL(phy_restore_page);
782 
783 /**
784  * phy_read_paged() - Convenience function for reading a paged register
785  * @phydev: a pointer to a &struct phy_device
786  * @page: the page for the phy
787  * @regnum: register number
788  *
789  * Same rules as for phy_read().
790  */
791 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
792 {
793 	int ret = 0, oldpage;
794 
795 	oldpage = phy_select_page(phydev, page);
796 	if (oldpage >= 0)
797 		ret = __phy_read(phydev, regnum);
798 
799 	return phy_restore_page(phydev, oldpage, ret);
800 }
801 EXPORT_SYMBOL(phy_read_paged);
802 
803 /**
804  * phy_write_paged() - Convenience function for writing a paged register
805  * @phydev: a pointer to a &struct phy_device
806  * @page: the page for the phy
807  * @regnum: register number
808  * @val: value to write
809  *
810  * Same rules as for phy_write().
811  */
812 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
813 {
814 	int ret = 0, oldpage;
815 
816 	oldpage = phy_select_page(phydev, page);
817 	if (oldpage >= 0)
818 		ret = __phy_write(phydev, regnum, val);
819 
820 	return phy_restore_page(phydev, oldpage, ret);
821 }
822 EXPORT_SYMBOL(phy_write_paged);
823 
824 /**
825  * phy_modify_paged_changed() - Function for modifying a paged register
826  * @phydev: a pointer to a &struct phy_device
827  * @page: the page for the phy
828  * @regnum: register number
829  * @mask: bit mask of bits to clear
830  * @set: bit mask of bits to set
831  *
832  * Returns negative errno, 0 if there was no change, and 1 in case of change
833  */
834 int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
835 			     u16 mask, u16 set)
836 {
837 	int ret = 0, oldpage;
838 
839 	oldpage = phy_select_page(phydev, page);
840 	if (oldpage >= 0)
841 		ret = __phy_modify_changed(phydev, regnum, mask, set);
842 
843 	return phy_restore_page(phydev, oldpage, ret);
844 }
845 EXPORT_SYMBOL(phy_modify_paged_changed);
846 
847 /**
848  * phy_modify_paged() - Convenience function for modifying a paged register
849  * @phydev: a pointer to a &struct phy_device
850  * @page: the page for the phy
851  * @regnum: register number
852  * @mask: bit mask of bits to clear
853  * @set: bit mask of bits to set
854  *
855  * Same rules as for phy_read() and phy_write().
856  */
857 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
858 		     u16 mask, u16 set)
859 {
860 	int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);
861 
862 	return ret < 0 ? ret : 0;
863 }
864 EXPORT_SYMBOL(phy_modify_paged);
865