xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision f20c7d91)
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 != 75,
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_400000:
46 		return "400Gbps";
47 	case SPEED_UNKNOWN:
48 		return "Unknown";
49 	default:
50 		return "Unsupported (update phy-core.c)";
51 	}
52 }
53 EXPORT_SYMBOL_GPL(phy_speed_to_str);
54 
55 const char *phy_duplex_to_str(unsigned int duplex)
56 {
57 	if (duplex == DUPLEX_HALF)
58 		return "Half";
59 	if (duplex == DUPLEX_FULL)
60 		return "Full";
61 	if (duplex == DUPLEX_UNKNOWN)
62 		return "Unknown";
63 	return "Unsupported (update phy-core.c)";
64 }
65 EXPORT_SYMBOL_GPL(phy_duplex_to_str);
66 
67 /* A mapping of all SUPPORTED settings to speed/duplex.  This table
68  * must be grouped by speed and sorted in descending match priority
69  * - iow, descending speed. */
70 
71 #define PHY_SETTING(s, d, b) { .speed = SPEED_ ## s, .duplex = DUPLEX_ ## d, \
72 			       .bit = ETHTOOL_LINK_MODE_ ## b ## _BIT}
73 
74 static const struct phy_setting settings[] = {
75 	/* 400G */
76 	PHY_SETTING( 400000, FULL, 400000baseCR8_Full		),
77 	PHY_SETTING( 400000, FULL, 400000baseKR8_Full		),
78 	PHY_SETTING( 400000, FULL, 400000baseLR8_ER8_FR8_Full	),
79 	PHY_SETTING( 400000, FULL, 400000baseDR8_Full		),
80 	PHY_SETTING( 400000, FULL, 400000baseSR8_Full		),
81 	/* 200G */
82 	PHY_SETTING( 200000, FULL, 200000baseCR4_Full		),
83 	PHY_SETTING( 200000, FULL, 200000baseKR4_Full		),
84 	PHY_SETTING( 200000, FULL, 200000baseLR4_ER4_FR4_Full	),
85 	PHY_SETTING( 200000, FULL, 200000baseDR4_Full		),
86 	PHY_SETTING( 200000, FULL, 200000baseSR4_Full		),
87 	/* 100G */
88 	PHY_SETTING( 100000, FULL, 100000baseCR4_Full		),
89 	PHY_SETTING( 100000, FULL, 100000baseKR4_Full		),
90 	PHY_SETTING( 100000, FULL, 100000baseLR4_ER4_Full	),
91 	PHY_SETTING( 100000, FULL, 100000baseSR4_Full		),
92 	PHY_SETTING( 100000, FULL, 100000baseCR2_Full		),
93 	PHY_SETTING( 100000, FULL, 100000baseKR2_Full		),
94 	PHY_SETTING( 100000, FULL, 100000baseLR2_ER2_FR2_Full	),
95 	PHY_SETTING( 100000, FULL, 100000baseDR2_Full		),
96 	PHY_SETTING( 100000, FULL, 100000baseSR2_Full		),
97 	/* 56G */
98 	PHY_SETTING(  56000, FULL,  56000baseCR4_Full	  	),
99 	PHY_SETTING(  56000, FULL,  56000baseKR4_Full	  	),
100 	PHY_SETTING(  56000, FULL,  56000baseLR4_Full	  	),
101 	PHY_SETTING(  56000, FULL,  56000baseSR4_Full	  	),
102 	/* 50G */
103 	PHY_SETTING(  50000, FULL,  50000baseCR2_Full		),
104 	PHY_SETTING(  50000, FULL,  50000baseKR2_Full		),
105 	PHY_SETTING(  50000, FULL,  50000baseSR2_Full		),
106 	PHY_SETTING(  50000, FULL,  50000baseCR_Full		),
107 	PHY_SETTING(  50000, FULL,  50000baseKR_Full		),
108 	PHY_SETTING(  50000, FULL,  50000baseLR_ER_FR_Full	),
109 	PHY_SETTING(  50000, FULL,  50000baseDR_Full		),
110 	PHY_SETTING(  50000, FULL,  50000baseSR_Full		),
111 	/* 40G */
112 	PHY_SETTING(  40000, FULL,  40000baseCR4_Full		),
113 	PHY_SETTING(  40000, FULL,  40000baseKR4_Full		),
114 	PHY_SETTING(  40000, FULL,  40000baseLR4_Full		),
115 	PHY_SETTING(  40000, FULL,  40000baseSR4_Full		),
116 	/* 25G */
117 	PHY_SETTING(  25000, FULL,  25000baseCR_Full		),
118 	PHY_SETTING(  25000, FULL,  25000baseKR_Full		),
119 	PHY_SETTING(  25000, FULL,  25000baseSR_Full		),
120 	/* 20G */
121 	PHY_SETTING(  20000, FULL,  20000baseKR2_Full		),
122 	PHY_SETTING(  20000, FULL,  20000baseMLD2_Full		),
123 	/* 10G */
124 	PHY_SETTING(  10000, FULL,  10000baseCR_Full		),
125 	PHY_SETTING(  10000, FULL,  10000baseER_Full		),
126 	PHY_SETTING(  10000, FULL,  10000baseKR_Full		),
127 	PHY_SETTING(  10000, FULL,  10000baseKX4_Full		),
128 	PHY_SETTING(  10000, FULL,  10000baseLR_Full		),
129 	PHY_SETTING(  10000, FULL,  10000baseLRM_Full		),
130 	PHY_SETTING(  10000, FULL,  10000baseR_FEC		),
131 	PHY_SETTING(  10000, FULL,  10000baseSR_Full		),
132 	PHY_SETTING(  10000, FULL,  10000baseT_Full		),
133 	/* 5G */
134 	PHY_SETTING(   5000, FULL,   5000baseT_Full		),
135 	/* 2.5G */
136 	PHY_SETTING(   2500, FULL,   2500baseT_Full		),
137 	PHY_SETTING(   2500, FULL,   2500baseX_Full		),
138 	/* 1G */
139 	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
140 	PHY_SETTING(   1000, FULL,   1000baseT_Full		),
141 	PHY_SETTING(   1000, HALF,   1000baseT_Half		),
142 	PHY_SETTING(   1000, FULL,   1000baseT1_Full		),
143 	PHY_SETTING(   1000, FULL,   1000baseX_Full		),
144 	/* 100M */
145 	PHY_SETTING(    100, FULL,    100baseT_Full		),
146 	PHY_SETTING(    100, FULL,    100baseT1_Full		),
147 	PHY_SETTING(    100, HALF,    100baseT_Half		),
148 	/* 10M */
149 	PHY_SETTING(     10, FULL,     10baseT_Full		),
150 	PHY_SETTING(     10, HALF,     10baseT_Half		),
151 };
152 #undef PHY_SETTING
153 
154 /**
155  * phy_lookup_setting - lookup a PHY setting
156  * @speed: speed to match
157  * @duplex: duplex to match
158  * @mask: allowed link modes
159  * @exact: an exact match is required
160  *
161  * Search the settings array for a setting that matches the speed and
162  * duplex, and which is supported.
163  *
164  * If @exact is unset, either an exact match or %NULL for no match will
165  * be returned.
166  *
167  * If @exact is set, an exact match, the fastest supported setting at
168  * or below the specified speed, the slowest supported setting, or if
169  * they all fail, %NULL will be returned.
170  */
171 const struct phy_setting *
172 phy_lookup_setting(int speed, int duplex, const unsigned long *mask, bool exact)
173 {
174 	const struct phy_setting *p, *match = NULL, *last = NULL;
175 	int i;
176 
177 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
178 		if (p->bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
179 		    test_bit(p->bit, mask)) {
180 			last = p;
181 			if (p->speed == speed && p->duplex == duplex) {
182 				/* Exact match for speed and duplex */
183 				match = p;
184 				break;
185 			} else if (!exact) {
186 				if (!match && p->speed <= speed)
187 					/* Candidate */
188 					match = p;
189 
190 				if (p->speed < speed)
191 					break;
192 			}
193 		}
194 	}
195 
196 	if (!match && !exact)
197 		match = last;
198 
199 	return match;
200 }
201 EXPORT_SYMBOL_GPL(phy_lookup_setting);
202 
203 size_t phy_speeds(unsigned int *speeds, size_t size,
204 		  unsigned long *mask)
205 {
206 	size_t count;
207 	int i;
208 
209 	for (i = 0, count = 0; i < ARRAY_SIZE(settings) && count < size; i++)
210 		if (settings[i].bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
211 		    test_bit(settings[i].bit, mask) &&
212 		    (count == 0 || speeds[count - 1] != settings[i].speed))
213 			speeds[count++] = settings[i].speed;
214 
215 	return count;
216 }
217 
218 static int __set_linkmode_max_speed(u32 max_speed, unsigned long *addr)
219 {
220 	const struct phy_setting *p;
221 	int i;
222 
223 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
224 		if (p->speed > max_speed)
225 			linkmode_clear_bit(p->bit, addr);
226 		else
227 			break;
228 	}
229 
230 	return 0;
231 }
232 
233 static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
234 {
235 	return __set_linkmode_max_speed(max_speed, phydev->supported);
236 }
237 
238 int phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
239 {
240 	int err;
241 
242 	err = __set_phy_supported(phydev, max_speed);
243 	if (err)
244 		return err;
245 
246 	phy_advertise_supported(phydev);
247 
248 	return 0;
249 }
250 EXPORT_SYMBOL(phy_set_max_speed);
251 
252 void of_set_phy_supported(struct phy_device *phydev)
253 {
254 	struct device_node *node = phydev->mdio.dev.of_node;
255 	u32 max_speed;
256 
257 	if (!IS_ENABLED(CONFIG_OF_MDIO))
258 		return;
259 
260 	if (!node)
261 		return;
262 
263 	if (!of_property_read_u32(node, "max-speed", &max_speed))
264 		__set_phy_supported(phydev, max_speed);
265 }
266 
267 void of_set_phy_eee_broken(struct phy_device *phydev)
268 {
269 	struct device_node *node = phydev->mdio.dev.of_node;
270 	u32 broken = 0;
271 
272 	if (!IS_ENABLED(CONFIG_OF_MDIO))
273 		return;
274 
275 	if (!node)
276 		return;
277 
278 	if (of_property_read_bool(node, "eee-broken-100tx"))
279 		broken |= MDIO_EEE_100TX;
280 	if (of_property_read_bool(node, "eee-broken-1000t"))
281 		broken |= MDIO_EEE_1000T;
282 	if (of_property_read_bool(node, "eee-broken-10gt"))
283 		broken |= MDIO_EEE_10GT;
284 	if (of_property_read_bool(node, "eee-broken-1000kx"))
285 		broken |= MDIO_EEE_1000KX;
286 	if (of_property_read_bool(node, "eee-broken-10gkx4"))
287 		broken |= MDIO_EEE_10GKX4;
288 	if (of_property_read_bool(node, "eee-broken-10gkr"))
289 		broken |= MDIO_EEE_10GKR;
290 
291 	phydev->eee_broken_modes = broken;
292 }
293 
294 void phy_resolve_aneg_pause(struct phy_device *phydev)
295 {
296 	if (phydev->duplex == DUPLEX_FULL) {
297 		phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
298 						  phydev->lp_advertising);
299 		phydev->asym_pause = linkmode_test_bit(
300 			ETHTOOL_LINK_MODE_Asym_Pause_BIT,
301 			phydev->lp_advertising);
302 	}
303 }
304 EXPORT_SYMBOL_GPL(phy_resolve_aneg_pause);
305 
306 /**
307  * phy_resolve_aneg_linkmode - resolve the advertisements into phy settings
308  * @phydev: The phy_device struct
309  *
310  * Resolve our and the link partner advertisements into their corresponding
311  * speed and duplex. If full duplex was negotiated, extract the pause mode
312  * from the link partner mask.
313  */
314 void phy_resolve_aneg_linkmode(struct phy_device *phydev)
315 {
316 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
317 	int i;
318 
319 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
320 
321 	for (i = 0; i < ARRAY_SIZE(settings); i++)
322 		if (test_bit(settings[i].bit, common)) {
323 			phydev->speed = settings[i].speed;
324 			phydev->duplex = settings[i].duplex;
325 			break;
326 		}
327 
328 	phy_resolve_aneg_pause(phydev);
329 }
330 EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
331 
332 /**
333  * phy_check_downshift - check whether downshift occurred
334  * @phydev: The phy_device struct
335  *
336  * Check whether a downshift to a lower speed occurred. If this should be the
337  * case warn the user.
338  * Prerequisite for detecting downshift is that PHY driver implements the
339  * read_status callback and sets phydev->speed to the actual link speed.
340  */
341 void phy_check_downshift(struct phy_device *phydev)
342 {
343 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
344 	int i, speed = SPEED_UNKNOWN;
345 
346 	phydev->downshifted_rate = 0;
347 
348 	if (phydev->autoneg == AUTONEG_DISABLE ||
349 	    phydev->speed == SPEED_UNKNOWN)
350 		return;
351 
352 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
353 
354 	for (i = 0; i < ARRAY_SIZE(settings); i++)
355 		if (test_bit(settings[i].bit, common)) {
356 			speed = settings[i].speed;
357 			break;
358 		}
359 
360 	if (speed == SPEED_UNKNOWN || phydev->speed >= speed)
361 		return;
362 
363 	phydev_warn(phydev, "Downshift occurred from negotiated speed %s to actual speed %s, check cabling!\n",
364 		    phy_speed_to_str(speed), phy_speed_to_str(phydev->speed));
365 
366 	phydev->downshifted_rate = 1;
367 }
368 EXPORT_SYMBOL_GPL(phy_check_downshift);
369 
370 static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
371 {
372 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
373 	int i = ARRAY_SIZE(settings);
374 
375 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
376 
377 	while (--i >= 0) {
378 		if (test_bit(settings[i].bit, common)) {
379 			if (fdx_only && settings[i].duplex != DUPLEX_FULL)
380 				continue;
381 			return settings[i].speed;
382 		}
383 	}
384 
385 	return SPEED_UNKNOWN;
386 }
387 
388 int phy_speed_down_core(struct phy_device *phydev)
389 {
390 	int min_common_speed = phy_resolve_min_speed(phydev, true);
391 
392 	if (min_common_speed == SPEED_UNKNOWN)
393 		return -EINVAL;
394 
395 	return __set_linkmode_max_speed(min_common_speed, phydev->advertising);
396 }
397 
398 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
399 			     u16 regnum)
400 {
401 	/* Write the desired MMD Devad */
402 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
403 
404 	/* Write the desired MMD register address */
405 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
406 
407 	/* Select the Function : DATA with no post increment */
408 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
409 			devad | MII_MMD_CTRL_NOINCR);
410 }
411 
412 /**
413  * __phy_read_mmd - Convenience function for reading a register
414  * from an MMD on a given PHY.
415  * @phydev: The phy_device struct
416  * @devad: The MMD to read from (0..31)
417  * @regnum: The register on the MMD to read (0..65535)
418  *
419  * Same rules as for __phy_read();
420  */
421 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
422 {
423 	int val;
424 
425 	if (regnum > (u16)~0 || devad > 32)
426 		return -EINVAL;
427 
428 	if (phydev->drv && phydev->drv->read_mmd) {
429 		val = phydev->drv->read_mmd(phydev, devad, regnum);
430 	} else if (phydev->is_c45) {
431 		val = __mdiobus_c45_read(phydev->mdio.bus, phydev->mdio.addr,
432 					 devad, regnum);
433 	} else {
434 		struct mii_bus *bus = phydev->mdio.bus;
435 		int phy_addr = phydev->mdio.addr;
436 
437 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
438 
439 		/* Read the content of the MMD's selected register */
440 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
441 	}
442 	return val;
443 }
444 EXPORT_SYMBOL(__phy_read_mmd);
445 
446 /**
447  * phy_read_mmd - Convenience function for reading a register
448  * from an MMD on a given PHY.
449  * @phydev: The phy_device struct
450  * @devad: The MMD to read from
451  * @regnum: The register on the MMD to read
452  *
453  * Same rules as for phy_read();
454  */
455 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
456 {
457 	int ret;
458 
459 	phy_lock_mdio_bus(phydev);
460 	ret = __phy_read_mmd(phydev, devad, regnum);
461 	phy_unlock_mdio_bus(phydev);
462 
463 	return ret;
464 }
465 EXPORT_SYMBOL(phy_read_mmd);
466 
467 /**
468  * __phy_write_mmd - Convenience function for writing a register
469  * on an MMD on a given PHY.
470  * @phydev: The phy_device struct
471  * @devad: The MMD to read from
472  * @regnum: The register on the MMD to read
473  * @val: value to write to @regnum
474  *
475  * Same rules as for __phy_write();
476  */
477 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
478 {
479 	int ret;
480 
481 	if (regnum > (u16)~0 || devad > 32)
482 		return -EINVAL;
483 
484 	if (phydev->drv && phydev->drv->write_mmd) {
485 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
486 	} else if (phydev->is_c45) {
487 		ret = __mdiobus_c45_write(phydev->mdio.bus, phydev->mdio.addr,
488 					  devad, regnum, val);
489 	} else {
490 		struct mii_bus *bus = phydev->mdio.bus;
491 		int phy_addr = phydev->mdio.addr;
492 
493 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
494 
495 		/* Write the data into MMD's selected register */
496 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
497 
498 		ret = 0;
499 	}
500 	return ret;
501 }
502 EXPORT_SYMBOL(__phy_write_mmd);
503 
504 /**
505  * phy_write_mmd - Convenience function for writing a register
506  * on an MMD on a given PHY.
507  * @phydev: The phy_device struct
508  * @devad: The MMD to read from
509  * @regnum: The register on the MMD to read
510  * @val: value to write to @regnum
511  *
512  * Same rules as for phy_write();
513  */
514 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
515 {
516 	int ret;
517 
518 	phy_lock_mdio_bus(phydev);
519 	ret = __phy_write_mmd(phydev, devad, regnum, val);
520 	phy_unlock_mdio_bus(phydev);
521 
522 	return ret;
523 }
524 EXPORT_SYMBOL(phy_write_mmd);
525 
526 /**
527  * phy_modify_changed - Function for modifying a PHY register
528  * @phydev: the phy_device struct
529  * @regnum: register number to modify
530  * @mask: bit mask of bits to clear
531  * @set: new value of bits set in mask to write to @regnum
532  *
533  * NOTE: MUST NOT be called from interrupt context,
534  * because the bus read/write functions may wait for an interrupt
535  * to conclude the operation.
536  *
537  * Returns negative errno, 0 if there was no change, and 1 in case of change
538  */
539 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
540 {
541 	int ret;
542 
543 	phy_lock_mdio_bus(phydev);
544 	ret = __phy_modify_changed(phydev, regnum, mask, set);
545 	phy_unlock_mdio_bus(phydev);
546 
547 	return ret;
548 }
549 EXPORT_SYMBOL_GPL(phy_modify_changed);
550 
551 /**
552  * __phy_modify - Convenience function for modifying a PHY register
553  * @phydev: the phy_device struct
554  * @regnum: register number to modify
555  * @mask: bit mask of bits to clear
556  * @set: new value of bits set in mask to write to @regnum
557  *
558  * NOTE: MUST NOT be called from interrupt context,
559  * because the bus read/write functions may wait for an interrupt
560  * to conclude the operation.
561  */
562 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
563 {
564 	int ret;
565 
566 	ret = __phy_modify_changed(phydev, regnum, mask, set);
567 
568 	return ret < 0 ? ret : 0;
569 }
570 EXPORT_SYMBOL_GPL(__phy_modify);
571 
572 /**
573  * phy_modify - Convenience function for modifying a given PHY register
574  * @phydev: the phy_device struct
575  * @regnum: register number to write
576  * @mask: bit mask of bits to clear
577  * @set: new value of bits set in mask to write to @regnum
578  *
579  * NOTE: MUST NOT be called from interrupt context,
580  * because the bus read/write functions may wait for an interrupt
581  * to conclude the operation.
582  */
583 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
584 {
585 	int ret;
586 
587 	phy_lock_mdio_bus(phydev);
588 	ret = __phy_modify(phydev, regnum, mask, set);
589 	phy_unlock_mdio_bus(phydev);
590 
591 	return ret;
592 }
593 EXPORT_SYMBOL_GPL(phy_modify);
594 
595 /**
596  * __phy_modify_mmd_changed - Function for modifying a register on MMD
597  * @phydev: the phy_device struct
598  * @devad: the MMD containing register to modify
599  * @regnum: register number to modify
600  * @mask: bit mask of bits to clear
601  * @set: new value of bits set in mask to write to @regnum
602  *
603  * Unlocked helper function which allows a MMD register to be modified as
604  * new register value = (old register value & ~mask) | set
605  *
606  * Returns negative errno, 0 if there was no change, and 1 in case of change
607  */
608 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
609 			     u16 mask, u16 set)
610 {
611 	int new, ret;
612 
613 	ret = __phy_read_mmd(phydev, devad, regnum);
614 	if (ret < 0)
615 		return ret;
616 
617 	new = (ret & ~mask) | set;
618 	if (new == ret)
619 		return 0;
620 
621 	ret = __phy_write_mmd(phydev, devad, regnum, new);
622 
623 	return ret < 0 ? ret : 1;
624 }
625 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
626 
627 /**
628  * phy_modify_mmd_changed - Function for modifying a register on MMD
629  * @phydev: the phy_device struct
630  * @devad: the MMD containing register to modify
631  * @regnum: register number to modify
632  * @mask: bit mask of bits to clear
633  * @set: new value of bits set in mask to write to @regnum
634  *
635  * NOTE: MUST NOT be called from interrupt context,
636  * because the bus read/write functions may wait for an interrupt
637  * to conclude the operation.
638  *
639  * Returns negative errno, 0 if there was no change, and 1 in case of change
640  */
641 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
642 			   u16 mask, u16 set)
643 {
644 	int ret;
645 
646 	phy_lock_mdio_bus(phydev);
647 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
648 	phy_unlock_mdio_bus(phydev);
649 
650 	return ret;
651 }
652 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
653 
654 /**
655  * __phy_modify_mmd - Convenience function for modifying a register on MMD
656  * @phydev: the phy_device struct
657  * @devad: the MMD containing register to modify
658  * @regnum: register number to modify
659  * @mask: bit mask of bits to clear
660  * @set: new value of bits set in mask to write to @regnum
661  *
662  * NOTE: MUST NOT be called from interrupt context,
663  * because the bus read/write functions may wait for an interrupt
664  * to conclude the operation.
665  */
666 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
667 		     u16 mask, u16 set)
668 {
669 	int ret;
670 
671 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
672 
673 	return ret < 0 ? ret : 0;
674 }
675 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
676 
677 /**
678  * phy_modify_mmd - Convenience function for modifying a register on MMD
679  * @phydev: the phy_device struct
680  * @devad: the MMD containing register to modify
681  * @regnum: register number to modify
682  * @mask: bit mask of bits to clear
683  * @set: new value of bits set in mask to write to @regnum
684  *
685  * NOTE: MUST NOT be called from interrupt context,
686  * because the bus read/write functions may wait for an interrupt
687  * to conclude the operation.
688  */
689 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
690 		   u16 mask, u16 set)
691 {
692 	int ret;
693 
694 	phy_lock_mdio_bus(phydev);
695 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
696 	phy_unlock_mdio_bus(phydev);
697 
698 	return ret;
699 }
700 EXPORT_SYMBOL_GPL(phy_modify_mmd);
701 
702 static int __phy_read_page(struct phy_device *phydev)
703 {
704 	if (WARN_ONCE(!phydev->drv->read_page, "read_page callback not available, PHY driver not loaded?\n"))
705 		return -EOPNOTSUPP;
706 
707 	return phydev->drv->read_page(phydev);
708 }
709 
710 static int __phy_write_page(struct phy_device *phydev, int page)
711 {
712 	if (WARN_ONCE(!phydev->drv->write_page, "write_page callback not available, PHY driver not loaded?\n"))
713 		return -EOPNOTSUPP;
714 
715 	return phydev->drv->write_page(phydev, page);
716 }
717 
718 /**
719  * phy_save_page() - take the bus lock and save the current page
720  * @phydev: a pointer to a &struct phy_device
721  *
722  * Take the MDIO bus lock, and return the current page number. On error,
723  * returns a negative errno. phy_restore_page() must always be called
724  * after this, irrespective of success or failure of this call.
725  */
726 int phy_save_page(struct phy_device *phydev)
727 {
728 	phy_lock_mdio_bus(phydev);
729 	return __phy_read_page(phydev);
730 }
731 EXPORT_SYMBOL_GPL(phy_save_page);
732 
733 /**
734  * phy_select_page() - take the bus lock, save the current page, and set a page
735  * @phydev: a pointer to a &struct phy_device
736  * @page: desired page
737  *
738  * Take the MDIO bus lock to protect against concurrent access, save the
739  * current PHY page, and set the current page.  On error, returns a
740  * negative errno, otherwise returns the previous page number.
741  * phy_restore_page() must always be called after this, irrespective
742  * of success or failure of this call.
743  */
744 int phy_select_page(struct phy_device *phydev, int page)
745 {
746 	int ret, oldpage;
747 
748 	oldpage = ret = phy_save_page(phydev);
749 	if (ret < 0)
750 		return ret;
751 
752 	if (oldpage != page) {
753 		ret = __phy_write_page(phydev, page);
754 		if (ret < 0)
755 			return ret;
756 	}
757 
758 	return oldpage;
759 }
760 EXPORT_SYMBOL_GPL(phy_select_page);
761 
762 /**
763  * phy_restore_page() - restore the page register and release the bus lock
764  * @phydev: a pointer to a &struct phy_device
765  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
766  * @ret: operation's return code
767  *
768  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
769  * This function propagates the earliest error code from the group of
770  * operations.
771  *
772  * Returns:
773  *   @oldpage if it was a negative value, otherwise
774  *   @ret if it was a negative errno value, otherwise
775  *   phy_write_page()'s negative value if it were in error, otherwise
776  *   @ret.
777  */
778 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
779 {
780 	int r;
781 
782 	if (oldpage >= 0) {
783 		r = __phy_write_page(phydev, oldpage);
784 
785 		/* Propagate the operation return code if the page write
786 		 * was successful.
787 		 */
788 		if (ret >= 0 && r < 0)
789 			ret = r;
790 	} else {
791 		/* Propagate the phy page selection error code */
792 		ret = oldpage;
793 	}
794 
795 	phy_unlock_mdio_bus(phydev);
796 
797 	return ret;
798 }
799 EXPORT_SYMBOL_GPL(phy_restore_page);
800 
801 /**
802  * phy_read_paged() - Convenience function for reading a paged register
803  * @phydev: a pointer to a &struct phy_device
804  * @page: the page for the phy
805  * @regnum: register number
806  *
807  * Same rules as for phy_read().
808  */
809 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
810 {
811 	int ret = 0, oldpage;
812 
813 	oldpage = phy_select_page(phydev, page);
814 	if (oldpage >= 0)
815 		ret = __phy_read(phydev, regnum);
816 
817 	return phy_restore_page(phydev, oldpage, ret);
818 }
819 EXPORT_SYMBOL(phy_read_paged);
820 
821 /**
822  * phy_write_paged() - Convenience function for writing a paged register
823  * @phydev: a pointer to a &struct phy_device
824  * @page: the page for the phy
825  * @regnum: register number
826  * @val: value to write
827  *
828  * Same rules as for phy_write().
829  */
830 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
831 {
832 	int ret = 0, oldpage;
833 
834 	oldpage = phy_select_page(phydev, page);
835 	if (oldpage >= 0)
836 		ret = __phy_write(phydev, regnum, val);
837 
838 	return phy_restore_page(phydev, oldpage, ret);
839 }
840 EXPORT_SYMBOL(phy_write_paged);
841 
842 /**
843  * phy_modify_paged_changed() - Function for modifying a paged register
844  * @phydev: a pointer to a &struct phy_device
845  * @page: the page for the phy
846  * @regnum: register number
847  * @mask: bit mask of bits to clear
848  * @set: bit mask of bits to set
849  *
850  * Returns negative errno, 0 if there was no change, and 1 in case of change
851  */
852 int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
853 			     u16 mask, u16 set)
854 {
855 	int ret = 0, oldpage;
856 
857 	oldpage = phy_select_page(phydev, page);
858 	if (oldpage >= 0)
859 		ret = __phy_modify_changed(phydev, regnum, mask, set);
860 
861 	return phy_restore_page(phydev, oldpage, ret);
862 }
863 EXPORT_SYMBOL(phy_modify_paged_changed);
864 
865 /**
866  * phy_modify_paged() - Convenience function for modifying a paged register
867  * @phydev: a pointer to a &struct phy_device
868  * @page: the page for the phy
869  * @regnum: register number
870  * @mask: bit mask of bits to clear
871  * @set: bit mask of bits to set
872  *
873  * Same rules as for phy_read() and phy_write().
874  */
875 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
876 		     u16 mask, u16 set)
877 {
878 	int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);
879 
880 	return ret < 0 ? ret : 0;
881 }
882 EXPORT_SYMBOL(phy_modify_paged);
883