xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision f125e2d4)
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 != 74,
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 static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
333 {
334 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
335 	int i = ARRAY_SIZE(settings);
336 
337 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
338 
339 	while (--i >= 0) {
340 		if (test_bit(settings[i].bit, common)) {
341 			if (fdx_only && settings[i].duplex != DUPLEX_FULL)
342 				continue;
343 			return settings[i].speed;
344 		}
345 	}
346 
347 	return SPEED_UNKNOWN;
348 }
349 
350 int phy_speed_down_core(struct phy_device *phydev)
351 {
352 	int min_common_speed = phy_resolve_min_speed(phydev, true);
353 
354 	if (min_common_speed == SPEED_UNKNOWN)
355 		return -EINVAL;
356 
357 	return __set_linkmode_max_speed(min_common_speed, phydev->advertising);
358 }
359 
360 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
361 			     u16 regnum)
362 {
363 	/* Write the desired MMD Devad */
364 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
365 
366 	/* Write the desired MMD register address */
367 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
368 
369 	/* Select the Function : DATA with no post increment */
370 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
371 			devad | MII_MMD_CTRL_NOINCR);
372 }
373 
374 /**
375  * __phy_read_mmd - Convenience function for reading a register
376  * from an MMD on a given PHY.
377  * @phydev: The phy_device struct
378  * @devad: The MMD to read from (0..31)
379  * @regnum: The register on the MMD to read (0..65535)
380  *
381  * Same rules as for __phy_read();
382  */
383 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
384 {
385 	int val;
386 
387 	if (regnum > (u16)~0 || devad > 32)
388 		return -EINVAL;
389 
390 	if (phydev->drv && phydev->drv->read_mmd) {
391 		val = phydev->drv->read_mmd(phydev, devad, regnum);
392 	} else if (phydev->is_c45) {
393 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
394 
395 		val = __mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, addr);
396 	} else {
397 		struct mii_bus *bus = phydev->mdio.bus;
398 		int phy_addr = phydev->mdio.addr;
399 
400 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
401 
402 		/* Read the content of the MMD's selected register */
403 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
404 	}
405 	return val;
406 }
407 EXPORT_SYMBOL(__phy_read_mmd);
408 
409 /**
410  * phy_read_mmd - Convenience function for reading a register
411  * from an MMD on a given PHY.
412  * @phydev: The phy_device struct
413  * @devad: The MMD to read from
414  * @regnum: The register on the MMD to read
415  *
416  * Same rules as for phy_read();
417  */
418 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
419 {
420 	int ret;
421 
422 	phy_lock_mdio_bus(phydev);
423 	ret = __phy_read_mmd(phydev, devad, regnum);
424 	phy_unlock_mdio_bus(phydev);
425 
426 	return ret;
427 }
428 EXPORT_SYMBOL(phy_read_mmd);
429 
430 /**
431  * __phy_write_mmd - Convenience function for writing a register
432  * on an MMD on a given PHY.
433  * @phydev: The phy_device struct
434  * @devad: The MMD to read from
435  * @regnum: The register on the MMD to read
436  * @val: value to write to @regnum
437  *
438  * Same rules as for __phy_write();
439  */
440 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
441 {
442 	int ret;
443 
444 	if (regnum > (u16)~0 || devad > 32)
445 		return -EINVAL;
446 
447 	if (phydev->drv && phydev->drv->write_mmd) {
448 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
449 	} else if (phydev->is_c45) {
450 		u32 addr = MII_ADDR_C45 | (devad << 16) | (regnum & 0xffff);
451 
452 		ret = __mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
453 				      addr, val);
454 	} else {
455 		struct mii_bus *bus = phydev->mdio.bus;
456 		int phy_addr = phydev->mdio.addr;
457 
458 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
459 
460 		/* Write the data into MMD's selected register */
461 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
462 
463 		ret = 0;
464 	}
465 	return ret;
466 }
467 EXPORT_SYMBOL(__phy_write_mmd);
468 
469 /**
470  * phy_write_mmd - Convenience function for writing a register
471  * on an MMD on a given PHY.
472  * @phydev: The phy_device struct
473  * @devad: The MMD to read from
474  * @regnum: The register on the MMD to read
475  * @val: value to write to @regnum
476  *
477  * Same rules as for phy_write();
478  */
479 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
480 {
481 	int ret;
482 
483 	phy_lock_mdio_bus(phydev);
484 	ret = __phy_write_mmd(phydev, devad, regnum, val);
485 	phy_unlock_mdio_bus(phydev);
486 
487 	return ret;
488 }
489 EXPORT_SYMBOL(phy_write_mmd);
490 
491 /**
492  * __phy_modify_changed() - Convenience function for modifying a PHY register
493  * @phydev: a pointer to a &struct phy_device
494  * @regnum: register number
495  * @mask: bit mask of bits to clear
496  * @set: bit mask of bits to set
497  *
498  * Unlocked helper function which allows a PHY register to be modified as
499  * new register value = (old register value & ~mask) | set
500  *
501  * Returns negative errno, 0 if there was no change, and 1 in case of change
502  */
503 int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
504 			 u16 set)
505 {
506 	int new, ret;
507 
508 	ret = __phy_read(phydev, regnum);
509 	if (ret < 0)
510 		return ret;
511 
512 	new = (ret & ~mask) | set;
513 	if (new == ret)
514 		return 0;
515 
516 	ret = __phy_write(phydev, regnum, new);
517 
518 	return ret < 0 ? ret : 1;
519 }
520 EXPORT_SYMBOL_GPL(__phy_modify_changed);
521 
522 /**
523  * phy_modify_changed - Function for modifying a PHY register
524  * @phydev: the phy_device struct
525  * @regnum: register number to modify
526  * @mask: bit mask of bits to clear
527  * @set: new value of bits set in mask to write to @regnum
528  *
529  * NOTE: MUST NOT be called from interrupt context,
530  * because the bus read/write functions may wait for an interrupt
531  * to conclude the operation.
532  *
533  * Returns negative errno, 0 if there was no change, and 1 in case of change
534  */
535 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
536 {
537 	int ret;
538 
539 	phy_lock_mdio_bus(phydev);
540 	ret = __phy_modify_changed(phydev, regnum, mask, set);
541 	phy_unlock_mdio_bus(phydev);
542 
543 	return ret;
544 }
545 EXPORT_SYMBOL_GPL(phy_modify_changed);
546 
547 /**
548  * __phy_modify - Convenience function for modifying a PHY register
549  * @phydev: the phy_device struct
550  * @regnum: register number to modify
551  * @mask: bit mask of bits to clear
552  * @set: new value of bits set in mask to write to @regnum
553  *
554  * NOTE: MUST NOT be called from interrupt context,
555  * because the bus read/write functions may wait for an interrupt
556  * to conclude the operation.
557  */
558 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
559 {
560 	int ret;
561 
562 	ret = __phy_modify_changed(phydev, regnum, mask, set);
563 
564 	return ret < 0 ? ret : 0;
565 }
566 EXPORT_SYMBOL_GPL(__phy_modify);
567 
568 /**
569  * phy_modify - Convenience function for modifying a given PHY register
570  * @phydev: the phy_device struct
571  * @regnum: register number to write
572  * @mask: bit mask of bits to clear
573  * @set: new value of bits set in mask to write to @regnum
574  *
575  * NOTE: MUST NOT be called from interrupt context,
576  * because the bus read/write functions may wait for an interrupt
577  * to conclude the operation.
578  */
579 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
580 {
581 	int ret;
582 
583 	phy_lock_mdio_bus(phydev);
584 	ret = __phy_modify(phydev, regnum, mask, set);
585 	phy_unlock_mdio_bus(phydev);
586 
587 	return ret;
588 }
589 EXPORT_SYMBOL_GPL(phy_modify);
590 
591 /**
592  * __phy_modify_mmd_changed - Function for modifying a register on MMD
593  * @phydev: the phy_device struct
594  * @devad: the MMD containing register to modify
595  * @regnum: register number to modify
596  * @mask: bit mask of bits to clear
597  * @set: new value of bits set in mask to write to @regnum
598  *
599  * Unlocked helper function which allows a MMD register to be modified as
600  * new register value = (old register value & ~mask) | set
601  *
602  * Returns negative errno, 0 if there was no change, and 1 in case of change
603  */
604 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
605 			     u16 mask, u16 set)
606 {
607 	int new, ret;
608 
609 	ret = __phy_read_mmd(phydev, devad, regnum);
610 	if (ret < 0)
611 		return ret;
612 
613 	new = (ret & ~mask) | set;
614 	if (new == ret)
615 		return 0;
616 
617 	ret = __phy_write_mmd(phydev, devad, regnum, new);
618 
619 	return ret < 0 ? ret : 1;
620 }
621 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
622 
623 /**
624  * phy_modify_mmd_changed - Function for modifying a register on MMD
625  * @phydev: the phy_device struct
626  * @devad: the MMD containing register to modify
627  * @regnum: register number to modify
628  * @mask: bit mask of bits to clear
629  * @set: new value of bits set in mask to write to @regnum
630  *
631  * NOTE: MUST NOT be called from interrupt context,
632  * because the bus read/write functions may wait for an interrupt
633  * to conclude the operation.
634  *
635  * Returns negative errno, 0 if there was no change, and 1 in case of change
636  */
637 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
638 			   u16 mask, u16 set)
639 {
640 	int ret;
641 
642 	phy_lock_mdio_bus(phydev);
643 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
644 	phy_unlock_mdio_bus(phydev);
645 
646 	return ret;
647 }
648 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
649 
650 /**
651  * __phy_modify_mmd - Convenience function for modifying a register on MMD
652  * @phydev: the phy_device struct
653  * @devad: the MMD containing register to modify
654  * @regnum: register number to modify
655  * @mask: bit mask of bits to clear
656  * @set: new value of bits set in mask to write to @regnum
657  *
658  * NOTE: MUST NOT be called from interrupt context,
659  * because the bus read/write functions may wait for an interrupt
660  * to conclude the operation.
661  */
662 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
663 		     u16 mask, u16 set)
664 {
665 	int ret;
666 
667 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
668 
669 	return ret < 0 ? ret : 0;
670 }
671 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
672 
673 /**
674  * phy_modify_mmd - Convenience function for modifying a register on MMD
675  * @phydev: the phy_device struct
676  * @devad: the MMD containing register to modify
677  * @regnum: register number to modify
678  * @mask: bit mask of bits to clear
679  * @set: new value of bits set in mask to write to @regnum
680  *
681  * NOTE: MUST NOT be called from interrupt context,
682  * because the bus read/write functions may wait for an interrupt
683  * to conclude the operation.
684  */
685 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
686 		   u16 mask, u16 set)
687 {
688 	int ret;
689 
690 	phy_lock_mdio_bus(phydev);
691 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
692 	phy_unlock_mdio_bus(phydev);
693 
694 	return ret;
695 }
696 EXPORT_SYMBOL_GPL(phy_modify_mmd);
697 
698 static int __phy_read_page(struct phy_device *phydev)
699 {
700 	if (WARN_ONCE(!phydev->drv->read_page, "read_page callback not available, PHY driver not loaded?\n"))
701 		return -EOPNOTSUPP;
702 
703 	return phydev->drv->read_page(phydev);
704 }
705 
706 static int __phy_write_page(struct phy_device *phydev, int page)
707 {
708 	if (WARN_ONCE(!phydev->drv->write_page, "write_page callback not available, PHY driver not loaded?\n"))
709 		return -EOPNOTSUPP;
710 
711 	return phydev->drv->write_page(phydev, page);
712 }
713 
714 /**
715  * phy_save_page() - take the bus lock and save the current page
716  * @phydev: a pointer to a &struct phy_device
717  *
718  * Take the MDIO bus lock, and return the current page number. On error,
719  * returns a negative errno. phy_restore_page() must always be called
720  * after this, irrespective of success or failure of this call.
721  */
722 int phy_save_page(struct phy_device *phydev)
723 {
724 	phy_lock_mdio_bus(phydev);
725 	return __phy_read_page(phydev);
726 }
727 EXPORT_SYMBOL_GPL(phy_save_page);
728 
729 /**
730  * phy_select_page() - take the bus lock, save the current page, and set a page
731  * @phydev: a pointer to a &struct phy_device
732  * @page: desired page
733  *
734  * Take the MDIO bus lock to protect against concurrent access, save the
735  * current PHY page, and set the current page.  On error, returns a
736  * negative errno, otherwise returns the previous page number.
737  * phy_restore_page() must always be called after this, irrespective
738  * of success or failure of this call.
739  */
740 int phy_select_page(struct phy_device *phydev, int page)
741 {
742 	int ret, oldpage;
743 
744 	oldpage = ret = phy_save_page(phydev);
745 	if (ret < 0)
746 		return ret;
747 
748 	if (oldpage != page) {
749 		ret = __phy_write_page(phydev, page);
750 		if (ret < 0)
751 			return ret;
752 	}
753 
754 	return oldpage;
755 }
756 EXPORT_SYMBOL_GPL(phy_select_page);
757 
758 /**
759  * phy_restore_page() - restore the page register and release the bus lock
760  * @phydev: a pointer to a &struct phy_device
761  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
762  * @ret: operation's return code
763  *
764  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
765  * This function propagates the earliest error code from the group of
766  * operations.
767  *
768  * Returns:
769  *   @oldpage if it was a negative value, otherwise
770  *   @ret if it was a negative errno value, otherwise
771  *   phy_write_page()'s negative value if it were in error, otherwise
772  *   @ret.
773  */
774 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
775 {
776 	int r;
777 
778 	if (oldpage >= 0) {
779 		r = __phy_write_page(phydev, oldpage);
780 
781 		/* Propagate the operation return code if the page write
782 		 * was successful.
783 		 */
784 		if (ret >= 0 && r < 0)
785 			ret = r;
786 	} else {
787 		/* Propagate the phy page selection error code */
788 		ret = oldpage;
789 	}
790 
791 	phy_unlock_mdio_bus(phydev);
792 
793 	return ret;
794 }
795 EXPORT_SYMBOL_GPL(phy_restore_page);
796 
797 /**
798  * phy_read_paged() - Convenience function for reading a paged register
799  * @phydev: a pointer to a &struct phy_device
800  * @page: the page for the phy
801  * @regnum: register number
802  *
803  * Same rules as for phy_read().
804  */
805 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
806 {
807 	int ret = 0, oldpage;
808 
809 	oldpage = phy_select_page(phydev, page);
810 	if (oldpage >= 0)
811 		ret = __phy_read(phydev, regnum);
812 
813 	return phy_restore_page(phydev, oldpage, ret);
814 }
815 EXPORT_SYMBOL(phy_read_paged);
816 
817 /**
818  * phy_write_paged() - Convenience function for writing a paged register
819  * @phydev: a pointer to a &struct phy_device
820  * @page: the page for the phy
821  * @regnum: register number
822  * @val: value to write
823  *
824  * Same rules as for phy_write().
825  */
826 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
827 {
828 	int ret = 0, oldpage;
829 
830 	oldpage = phy_select_page(phydev, page);
831 	if (oldpage >= 0)
832 		ret = __phy_write(phydev, regnum, val);
833 
834 	return phy_restore_page(phydev, oldpage, ret);
835 }
836 EXPORT_SYMBOL(phy_write_paged);
837 
838 /**
839  * phy_modify_paged_changed() - Function for modifying a paged register
840  * @phydev: a pointer to a &struct phy_device
841  * @page: the page for the phy
842  * @regnum: register number
843  * @mask: bit mask of bits to clear
844  * @set: bit mask of bits to set
845  *
846  * Returns negative errno, 0 if there was no change, and 1 in case of change
847  */
848 int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
849 			     u16 mask, u16 set)
850 {
851 	int ret = 0, oldpage;
852 
853 	oldpage = phy_select_page(phydev, page);
854 	if (oldpage >= 0)
855 		ret = __phy_modify_changed(phydev, regnum, mask, set);
856 
857 	return phy_restore_page(phydev, oldpage, ret);
858 }
859 EXPORT_SYMBOL(phy_modify_paged_changed);
860 
861 /**
862  * phy_modify_paged() - Convenience function for modifying a paged register
863  * @phydev: a pointer to a &struct phy_device
864  * @page: the page for the phy
865  * @regnum: register number
866  * @mask: bit mask of bits to clear
867  * @set: bit mask of bits to set
868  *
869  * Same rules as for phy_read() and phy_write().
870  */
871 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
872 		     u16 mask, u16 set)
873 {
874 	int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);
875 
876 	return ret < 0 ? ret : 0;
877 }
878 EXPORT_SYMBOL(phy_modify_paged);
879