xref: /openbmc/linux/drivers/net/phy/phy-core.c (revision 29c37341)
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 != 90,
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 	PHY_SETTING( 400000, FULL, 400000baseCR4_Full		),
82 	PHY_SETTING( 400000, FULL, 400000baseKR4_Full		),
83 	PHY_SETTING( 400000, FULL, 400000baseLR4_ER4_FR4_Full	),
84 	PHY_SETTING( 400000, FULL, 400000baseDR4_Full		),
85 	PHY_SETTING( 400000, FULL, 400000baseSR4_Full		),
86 	/* 200G */
87 	PHY_SETTING( 200000, FULL, 200000baseCR4_Full		),
88 	PHY_SETTING( 200000, FULL, 200000baseKR4_Full		),
89 	PHY_SETTING( 200000, FULL, 200000baseLR4_ER4_FR4_Full	),
90 	PHY_SETTING( 200000, FULL, 200000baseDR4_Full		),
91 	PHY_SETTING( 200000, FULL, 200000baseSR4_Full		),
92 	PHY_SETTING( 200000, FULL, 200000baseCR2_Full		),
93 	PHY_SETTING( 200000, FULL, 200000baseKR2_Full		),
94 	PHY_SETTING( 200000, FULL, 200000baseLR2_ER2_FR2_Full	),
95 	PHY_SETTING( 200000, FULL, 200000baseDR2_Full		),
96 	PHY_SETTING( 200000, FULL, 200000baseSR2_Full		),
97 	/* 100G */
98 	PHY_SETTING( 100000, FULL, 100000baseCR4_Full		),
99 	PHY_SETTING( 100000, FULL, 100000baseKR4_Full		),
100 	PHY_SETTING( 100000, FULL, 100000baseLR4_ER4_Full	),
101 	PHY_SETTING( 100000, FULL, 100000baseSR4_Full		),
102 	PHY_SETTING( 100000, FULL, 100000baseCR2_Full		),
103 	PHY_SETTING( 100000, FULL, 100000baseKR2_Full		),
104 	PHY_SETTING( 100000, FULL, 100000baseLR2_ER2_FR2_Full	),
105 	PHY_SETTING( 100000, FULL, 100000baseDR2_Full		),
106 	PHY_SETTING( 100000, FULL, 100000baseSR2_Full		),
107 	PHY_SETTING( 100000, FULL, 100000baseCR_Full		),
108 	PHY_SETTING( 100000, FULL, 100000baseKR_Full		),
109 	PHY_SETTING( 100000, FULL, 100000baseLR_ER_FR_Full	),
110 	PHY_SETTING( 100000, FULL, 100000baseDR_Full		),
111 	PHY_SETTING( 100000, FULL, 100000baseSR_Full		),
112 	/* 56G */
113 	PHY_SETTING(  56000, FULL,  56000baseCR4_Full	  	),
114 	PHY_SETTING(  56000, FULL,  56000baseKR4_Full	  	),
115 	PHY_SETTING(  56000, FULL,  56000baseLR4_Full	  	),
116 	PHY_SETTING(  56000, FULL,  56000baseSR4_Full	  	),
117 	/* 50G */
118 	PHY_SETTING(  50000, FULL,  50000baseCR2_Full		),
119 	PHY_SETTING(  50000, FULL,  50000baseKR2_Full		),
120 	PHY_SETTING(  50000, FULL,  50000baseSR2_Full		),
121 	PHY_SETTING(  50000, FULL,  50000baseCR_Full		),
122 	PHY_SETTING(  50000, FULL,  50000baseKR_Full		),
123 	PHY_SETTING(  50000, FULL,  50000baseLR_ER_FR_Full	),
124 	PHY_SETTING(  50000, FULL,  50000baseDR_Full		),
125 	PHY_SETTING(  50000, FULL,  50000baseSR_Full		),
126 	/* 40G */
127 	PHY_SETTING(  40000, FULL,  40000baseCR4_Full		),
128 	PHY_SETTING(  40000, FULL,  40000baseKR4_Full		),
129 	PHY_SETTING(  40000, FULL,  40000baseLR4_Full		),
130 	PHY_SETTING(  40000, FULL,  40000baseSR4_Full		),
131 	/* 25G */
132 	PHY_SETTING(  25000, FULL,  25000baseCR_Full		),
133 	PHY_SETTING(  25000, FULL,  25000baseKR_Full		),
134 	PHY_SETTING(  25000, FULL,  25000baseSR_Full		),
135 	/* 20G */
136 	PHY_SETTING(  20000, FULL,  20000baseKR2_Full		),
137 	PHY_SETTING(  20000, FULL,  20000baseMLD2_Full		),
138 	/* 10G */
139 	PHY_SETTING(  10000, FULL,  10000baseCR_Full		),
140 	PHY_SETTING(  10000, FULL,  10000baseER_Full		),
141 	PHY_SETTING(  10000, FULL,  10000baseKR_Full		),
142 	PHY_SETTING(  10000, FULL,  10000baseKX4_Full		),
143 	PHY_SETTING(  10000, FULL,  10000baseLR_Full		),
144 	PHY_SETTING(  10000, FULL,  10000baseLRM_Full		),
145 	PHY_SETTING(  10000, FULL,  10000baseR_FEC		),
146 	PHY_SETTING(  10000, FULL,  10000baseSR_Full		),
147 	PHY_SETTING(  10000, FULL,  10000baseT_Full		),
148 	/* 5G */
149 	PHY_SETTING(   5000, FULL,   5000baseT_Full		),
150 	/* 2.5G */
151 	PHY_SETTING(   2500, FULL,   2500baseT_Full		),
152 	PHY_SETTING(   2500, FULL,   2500baseX_Full		),
153 	/* 1G */
154 	PHY_SETTING(   1000, FULL,   1000baseKX_Full		),
155 	PHY_SETTING(   1000, FULL,   1000baseT_Full		),
156 	PHY_SETTING(   1000, HALF,   1000baseT_Half		),
157 	PHY_SETTING(   1000, FULL,   1000baseT1_Full		),
158 	PHY_SETTING(   1000, FULL,   1000baseX_Full		),
159 	/* 100M */
160 	PHY_SETTING(    100, FULL,    100baseT_Full		),
161 	PHY_SETTING(    100, FULL,    100baseT1_Full		),
162 	PHY_SETTING(    100, HALF,    100baseT_Half		),
163 	/* 10M */
164 	PHY_SETTING(     10, FULL,     10baseT_Full		),
165 	PHY_SETTING(     10, HALF,     10baseT_Half		),
166 };
167 #undef PHY_SETTING
168 
169 /**
170  * phy_lookup_setting - lookup a PHY setting
171  * @speed: speed to match
172  * @duplex: duplex to match
173  * @mask: allowed link modes
174  * @exact: an exact match is required
175  *
176  * Search the settings array for a setting that matches the speed and
177  * duplex, and which is supported.
178  *
179  * If @exact is unset, either an exact match or %NULL for no match will
180  * be returned.
181  *
182  * If @exact is set, an exact match, the fastest supported setting at
183  * or below the specified speed, the slowest supported setting, or if
184  * they all fail, %NULL will be returned.
185  */
186 const struct phy_setting *
187 phy_lookup_setting(int speed, int duplex, const unsigned long *mask, bool exact)
188 {
189 	const struct phy_setting *p, *match = NULL, *last = NULL;
190 	int i;
191 
192 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
193 		if (p->bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
194 		    test_bit(p->bit, mask)) {
195 			last = p;
196 			if (p->speed == speed && p->duplex == duplex) {
197 				/* Exact match for speed and duplex */
198 				match = p;
199 				break;
200 			} else if (!exact) {
201 				if (!match && p->speed <= speed)
202 					/* Candidate */
203 					match = p;
204 
205 				if (p->speed < speed)
206 					break;
207 			}
208 		}
209 	}
210 
211 	if (!match && !exact)
212 		match = last;
213 
214 	return match;
215 }
216 EXPORT_SYMBOL_GPL(phy_lookup_setting);
217 
218 size_t phy_speeds(unsigned int *speeds, size_t size,
219 		  unsigned long *mask)
220 {
221 	size_t count;
222 	int i;
223 
224 	for (i = 0, count = 0; i < ARRAY_SIZE(settings) && count < size; i++)
225 		if (settings[i].bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
226 		    test_bit(settings[i].bit, mask) &&
227 		    (count == 0 || speeds[count - 1] != settings[i].speed))
228 			speeds[count++] = settings[i].speed;
229 
230 	return count;
231 }
232 
233 static int __set_linkmode_max_speed(u32 max_speed, unsigned long *addr)
234 {
235 	const struct phy_setting *p;
236 	int i;
237 
238 	for (i = 0, p = settings; i < ARRAY_SIZE(settings); i++, p++) {
239 		if (p->speed > max_speed)
240 			linkmode_clear_bit(p->bit, addr);
241 		else
242 			break;
243 	}
244 
245 	return 0;
246 }
247 
248 static int __set_phy_supported(struct phy_device *phydev, u32 max_speed)
249 {
250 	return __set_linkmode_max_speed(max_speed, phydev->supported);
251 }
252 
253 int phy_set_max_speed(struct phy_device *phydev, u32 max_speed)
254 {
255 	int err;
256 
257 	err = __set_phy_supported(phydev, max_speed);
258 	if (err)
259 		return err;
260 
261 	phy_advertise_supported(phydev);
262 
263 	return 0;
264 }
265 EXPORT_SYMBOL(phy_set_max_speed);
266 
267 void of_set_phy_supported(struct phy_device *phydev)
268 {
269 	struct device_node *node = phydev->mdio.dev.of_node;
270 	u32 max_speed;
271 
272 	if (!IS_ENABLED(CONFIG_OF_MDIO))
273 		return;
274 
275 	if (!node)
276 		return;
277 
278 	if (!of_property_read_u32(node, "max-speed", &max_speed))
279 		__set_phy_supported(phydev, max_speed);
280 }
281 
282 void of_set_phy_eee_broken(struct phy_device *phydev)
283 {
284 	struct device_node *node = phydev->mdio.dev.of_node;
285 	u32 broken = 0;
286 
287 	if (!IS_ENABLED(CONFIG_OF_MDIO))
288 		return;
289 
290 	if (!node)
291 		return;
292 
293 	if (of_property_read_bool(node, "eee-broken-100tx"))
294 		broken |= MDIO_EEE_100TX;
295 	if (of_property_read_bool(node, "eee-broken-1000t"))
296 		broken |= MDIO_EEE_1000T;
297 	if (of_property_read_bool(node, "eee-broken-10gt"))
298 		broken |= MDIO_EEE_10GT;
299 	if (of_property_read_bool(node, "eee-broken-1000kx"))
300 		broken |= MDIO_EEE_1000KX;
301 	if (of_property_read_bool(node, "eee-broken-10gkx4"))
302 		broken |= MDIO_EEE_10GKX4;
303 	if (of_property_read_bool(node, "eee-broken-10gkr"))
304 		broken |= MDIO_EEE_10GKR;
305 
306 	phydev->eee_broken_modes = broken;
307 }
308 
309 void phy_resolve_aneg_pause(struct phy_device *phydev)
310 {
311 	if (phydev->duplex == DUPLEX_FULL) {
312 		phydev->pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
313 						  phydev->lp_advertising);
314 		phydev->asym_pause = linkmode_test_bit(
315 			ETHTOOL_LINK_MODE_Asym_Pause_BIT,
316 			phydev->lp_advertising);
317 	}
318 }
319 EXPORT_SYMBOL_GPL(phy_resolve_aneg_pause);
320 
321 /**
322  * phy_resolve_aneg_linkmode - resolve the advertisements into phy settings
323  * @phydev: The phy_device struct
324  *
325  * Resolve our and the link partner advertisements into their corresponding
326  * speed and duplex. If full duplex was negotiated, extract the pause mode
327  * from the link partner mask.
328  */
329 void phy_resolve_aneg_linkmode(struct phy_device *phydev)
330 {
331 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
332 	int i;
333 
334 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
335 
336 	for (i = 0; i < ARRAY_SIZE(settings); i++)
337 		if (test_bit(settings[i].bit, common)) {
338 			phydev->speed = settings[i].speed;
339 			phydev->duplex = settings[i].duplex;
340 			break;
341 		}
342 
343 	phy_resolve_aneg_pause(phydev);
344 }
345 EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
346 
347 /**
348  * phy_check_downshift - check whether downshift occurred
349  * @phydev: The phy_device struct
350  *
351  * Check whether a downshift to a lower speed occurred. If this should be the
352  * case warn the user.
353  * Prerequisite for detecting downshift is that PHY driver implements the
354  * read_status callback and sets phydev->speed to the actual link speed.
355  */
356 void phy_check_downshift(struct phy_device *phydev)
357 {
358 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
359 	int i, speed = SPEED_UNKNOWN;
360 
361 	phydev->downshifted_rate = 0;
362 
363 	if (phydev->autoneg == AUTONEG_DISABLE ||
364 	    phydev->speed == SPEED_UNKNOWN)
365 		return;
366 
367 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
368 
369 	for (i = 0; i < ARRAY_SIZE(settings); i++)
370 		if (test_bit(settings[i].bit, common)) {
371 			speed = settings[i].speed;
372 			break;
373 		}
374 
375 	if (speed == SPEED_UNKNOWN || phydev->speed >= speed)
376 		return;
377 
378 	phydev_warn(phydev, "Downshift occurred from negotiated speed %s to actual speed %s, check cabling!\n",
379 		    phy_speed_to_str(speed), phy_speed_to_str(phydev->speed));
380 
381 	phydev->downshifted_rate = 1;
382 }
383 EXPORT_SYMBOL_GPL(phy_check_downshift);
384 
385 static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
386 {
387 	__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
388 	int i = ARRAY_SIZE(settings);
389 
390 	linkmode_and(common, phydev->lp_advertising, phydev->advertising);
391 
392 	while (--i >= 0) {
393 		if (test_bit(settings[i].bit, common)) {
394 			if (fdx_only && settings[i].duplex != DUPLEX_FULL)
395 				continue;
396 			return settings[i].speed;
397 		}
398 	}
399 
400 	return SPEED_UNKNOWN;
401 }
402 
403 int phy_speed_down_core(struct phy_device *phydev)
404 {
405 	int min_common_speed = phy_resolve_min_speed(phydev, true);
406 
407 	if (min_common_speed == SPEED_UNKNOWN)
408 		return -EINVAL;
409 
410 	return __set_linkmode_max_speed(min_common_speed, phydev->advertising);
411 }
412 
413 static void mmd_phy_indirect(struct mii_bus *bus, int phy_addr, int devad,
414 			     u16 regnum)
415 {
416 	/* Write the desired MMD Devad */
417 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL, devad);
418 
419 	/* Write the desired MMD register address */
420 	__mdiobus_write(bus, phy_addr, MII_MMD_DATA, regnum);
421 
422 	/* Select the Function : DATA with no post increment */
423 	__mdiobus_write(bus, phy_addr, MII_MMD_CTRL,
424 			devad | MII_MMD_CTRL_NOINCR);
425 }
426 
427 /**
428  * __phy_read_mmd - Convenience function for reading a register
429  * from an MMD on a given PHY.
430  * @phydev: The phy_device struct
431  * @devad: The MMD to read from (0..31)
432  * @regnum: The register on the MMD to read (0..65535)
433  *
434  * Same rules as for __phy_read();
435  */
436 int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
437 {
438 	int val;
439 
440 	if (regnum > (u16)~0 || devad > 32)
441 		return -EINVAL;
442 
443 	if (phydev->drv && phydev->drv->read_mmd) {
444 		val = phydev->drv->read_mmd(phydev, devad, regnum);
445 	} else if (phydev->is_c45) {
446 		val = __mdiobus_c45_read(phydev->mdio.bus, phydev->mdio.addr,
447 					 devad, regnum);
448 	} else {
449 		struct mii_bus *bus = phydev->mdio.bus;
450 		int phy_addr = phydev->mdio.addr;
451 
452 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
453 
454 		/* Read the content of the MMD's selected register */
455 		val = __mdiobus_read(bus, phy_addr, MII_MMD_DATA);
456 	}
457 	return val;
458 }
459 EXPORT_SYMBOL(__phy_read_mmd);
460 
461 /**
462  * phy_read_mmd - Convenience function for reading a register
463  * from 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  *
468  * Same rules as for phy_read();
469  */
470 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
471 {
472 	int ret;
473 
474 	phy_lock_mdio_bus(phydev);
475 	ret = __phy_read_mmd(phydev, devad, regnum);
476 	phy_unlock_mdio_bus(phydev);
477 
478 	return ret;
479 }
480 EXPORT_SYMBOL(phy_read_mmd);
481 
482 /**
483  * __phy_write_mmd - Convenience function for writing a register
484  * on an MMD on a given PHY.
485  * @phydev: The phy_device struct
486  * @devad: The MMD to read from
487  * @regnum: The register on the MMD to read
488  * @val: value to write to @regnum
489  *
490  * Same rules as for __phy_write();
491  */
492 int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
493 {
494 	int ret;
495 
496 	if (regnum > (u16)~0 || devad > 32)
497 		return -EINVAL;
498 
499 	if (phydev->drv && phydev->drv->write_mmd) {
500 		ret = phydev->drv->write_mmd(phydev, devad, regnum, val);
501 	} else if (phydev->is_c45) {
502 		ret = __mdiobus_c45_write(phydev->mdio.bus, phydev->mdio.addr,
503 					  devad, regnum, val);
504 	} else {
505 		struct mii_bus *bus = phydev->mdio.bus;
506 		int phy_addr = phydev->mdio.addr;
507 
508 		mmd_phy_indirect(bus, phy_addr, devad, regnum);
509 
510 		/* Write the data into MMD's selected register */
511 		__mdiobus_write(bus, phy_addr, MII_MMD_DATA, val);
512 
513 		ret = 0;
514 	}
515 	return ret;
516 }
517 EXPORT_SYMBOL(__phy_write_mmd);
518 
519 /**
520  * phy_write_mmd - Convenience function for writing a register
521  * on an MMD on a given PHY.
522  * @phydev: The phy_device struct
523  * @devad: The MMD to read from
524  * @regnum: The register on the MMD to read
525  * @val: value to write to @regnum
526  *
527  * Same rules as for phy_write();
528  */
529 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val)
530 {
531 	int ret;
532 
533 	phy_lock_mdio_bus(phydev);
534 	ret = __phy_write_mmd(phydev, devad, regnum, val);
535 	phy_unlock_mdio_bus(phydev);
536 
537 	return ret;
538 }
539 EXPORT_SYMBOL(phy_write_mmd);
540 
541 /**
542  * phy_modify_changed - Function for modifying a PHY register
543  * @phydev: the phy_device struct
544  * @regnum: register number to modify
545  * @mask: bit mask of bits to clear
546  * @set: new value of bits set in mask to write to @regnum
547  *
548  * NOTE: MUST NOT be called from interrupt context,
549  * because the bus read/write functions may wait for an interrupt
550  * to conclude the operation.
551  *
552  * Returns negative errno, 0 if there was no change, and 1 in case of change
553  */
554 int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
555 {
556 	int ret;
557 
558 	phy_lock_mdio_bus(phydev);
559 	ret = __phy_modify_changed(phydev, regnum, mask, set);
560 	phy_unlock_mdio_bus(phydev);
561 
562 	return ret;
563 }
564 EXPORT_SYMBOL_GPL(phy_modify_changed);
565 
566 /**
567  * __phy_modify - Convenience function for modifying a PHY register
568  * @phydev: the phy_device struct
569  * @regnum: register number to modify
570  * @mask: bit mask of bits to clear
571  * @set: new value of bits set in mask to write to @regnum
572  *
573  * NOTE: MUST NOT be called from interrupt context,
574  * because the bus read/write functions may wait for an interrupt
575  * to conclude the operation.
576  */
577 int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
578 {
579 	int ret;
580 
581 	ret = __phy_modify_changed(phydev, regnum, mask, set);
582 
583 	return ret < 0 ? ret : 0;
584 }
585 EXPORT_SYMBOL_GPL(__phy_modify);
586 
587 /**
588  * phy_modify - Convenience function for modifying a given PHY register
589  * @phydev: the phy_device struct
590  * @regnum: register number to write
591  * @mask: bit mask of bits to clear
592  * @set: new value of bits set in mask to write to @regnum
593  *
594  * NOTE: MUST NOT be called from interrupt context,
595  * because the bus read/write functions may wait for an interrupt
596  * to conclude the operation.
597  */
598 int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
599 {
600 	int ret;
601 
602 	phy_lock_mdio_bus(phydev);
603 	ret = __phy_modify(phydev, regnum, mask, set);
604 	phy_unlock_mdio_bus(phydev);
605 
606 	return ret;
607 }
608 EXPORT_SYMBOL_GPL(phy_modify);
609 
610 /**
611  * __phy_modify_mmd_changed - Function for modifying a register on MMD
612  * @phydev: the phy_device struct
613  * @devad: the MMD containing register to modify
614  * @regnum: register number to modify
615  * @mask: bit mask of bits to clear
616  * @set: new value of bits set in mask to write to @regnum
617  *
618  * Unlocked helper function which allows a MMD register to be modified as
619  * new register value = (old register value & ~mask) | set
620  *
621  * Returns negative errno, 0 if there was no change, and 1 in case of change
622  */
623 int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
624 			     u16 mask, u16 set)
625 {
626 	int new, ret;
627 
628 	ret = __phy_read_mmd(phydev, devad, regnum);
629 	if (ret < 0)
630 		return ret;
631 
632 	new = (ret & ~mask) | set;
633 	if (new == ret)
634 		return 0;
635 
636 	ret = __phy_write_mmd(phydev, devad, regnum, new);
637 
638 	return ret < 0 ? ret : 1;
639 }
640 EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
641 
642 /**
643  * phy_modify_mmd_changed - 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  * Returns negative errno, 0 if there was no change, and 1 in case of change
655  */
656 int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
657 			   u16 mask, u16 set)
658 {
659 	int ret;
660 
661 	phy_lock_mdio_bus(phydev);
662 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
663 	phy_unlock_mdio_bus(phydev);
664 
665 	return ret;
666 }
667 EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
668 
669 /**
670  * __phy_modify_mmd - Convenience function for modifying a register on MMD
671  * @phydev: the phy_device struct
672  * @devad: the MMD containing register to modify
673  * @regnum: register number to modify
674  * @mask: bit mask of bits to clear
675  * @set: new value of bits set in mask to write to @regnum
676  *
677  * NOTE: MUST NOT be called from interrupt context,
678  * because the bus read/write functions may wait for an interrupt
679  * to conclude the operation.
680  */
681 int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
682 		     u16 mask, u16 set)
683 {
684 	int ret;
685 
686 	ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
687 
688 	return ret < 0 ? ret : 0;
689 }
690 EXPORT_SYMBOL_GPL(__phy_modify_mmd);
691 
692 /**
693  * phy_modify_mmd - Convenience function for modifying a register on MMD
694  * @phydev: the phy_device struct
695  * @devad: the MMD containing register to modify
696  * @regnum: register number to modify
697  * @mask: bit mask of bits to clear
698  * @set: new value of bits set in mask to write to @regnum
699  *
700  * NOTE: MUST NOT be called from interrupt context,
701  * because the bus read/write functions may wait for an interrupt
702  * to conclude the operation.
703  */
704 int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
705 		   u16 mask, u16 set)
706 {
707 	int ret;
708 
709 	phy_lock_mdio_bus(phydev);
710 	ret = __phy_modify_mmd(phydev, devad, regnum, mask, set);
711 	phy_unlock_mdio_bus(phydev);
712 
713 	return ret;
714 }
715 EXPORT_SYMBOL_GPL(phy_modify_mmd);
716 
717 static int __phy_read_page(struct phy_device *phydev)
718 {
719 	if (WARN_ONCE(!phydev->drv->read_page, "read_page callback not available, PHY driver not loaded?\n"))
720 		return -EOPNOTSUPP;
721 
722 	return phydev->drv->read_page(phydev);
723 }
724 
725 static int __phy_write_page(struct phy_device *phydev, int page)
726 {
727 	if (WARN_ONCE(!phydev->drv->write_page, "write_page callback not available, PHY driver not loaded?\n"))
728 		return -EOPNOTSUPP;
729 
730 	return phydev->drv->write_page(phydev, page);
731 }
732 
733 /**
734  * phy_save_page() - take the bus lock and save the current page
735  * @phydev: a pointer to a &struct phy_device
736  *
737  * Take the MDIO bus lock, and return the current page number. On error,
738  * returns a negative errno. phy_restore_page() must always be called
739  * after this, irrespective of success or failure of this call.
740  */
741 int phy_save_page(struct phy_device *phydev)
742 {
743 	phy_lock_mdio_bus(phydev);
744 	return __phy_read_page(phydev);
745 }
746 EXPORT_SYMBOL_GPL(phy_save_page);
747 
748 /**
749  * phy_select_page() - take the bus lock, save the current page, and set a page
750  * @phydev: a pointer to a &struct phy_device
751  * @page: desired page
752  *
753  * Take the MDIO bus lock to protect against concurrent access, save the
754  * current PHY page, and set the current page.  On error, returns a
755  * negative errno, otherwise returns the previous page number.
756  * phy_restore_page() must always be called after this, irrespective
757  * of success or failure of this call.
758  */
759 int phy_select_page(struct phy_device *phydev, int page)
760 {
761 	int ret, oldpage;
762 
763 	oldpage = ret = phy_save_page(phydev);
764 	if (ret < 0)
765 		return ret;
766 
767 	if (oldpage != page) {
768 		ret = __phy_write_page(phydev, page);
769 		if (ret < 0)
770 			return ret;
771 	}
772 
773 	return oldpage;
774 }
775 EXPORT_SYMBOL_GPL(phy_select_page);
776 
777 /**
778  * phy_restore_page() - restore the page register and release the bus lock
779  * @phydev: a pointer to a &struct phy_device
780  * @oldpage: the old page, return value from phy_save_page() or phy_select_page()
781  * @ret: operation's return code
782  *
783  * Release the MDIO bus lock, restoring @oldpage if it is a valid page.
784  * This function propagates the earliest error code from the group of
785  * operations.
786  *
787  * Returns:
788  *   @oldpage if it was a negative value, otherwise
789  *   @ret if it was a negative errno value, otherwise
790  *   phy_write_page()'s negative value if it were in error, otherwise
791  *   @ret.
792  */
793 int phy_restore_page(struct phy_device *phydev, int oldpage, int ret)
794 {
795 	int r;
796 
797 	if (oldpage >= 0) {
798 		r = __phy_write_page(phydev, oldpage);
799 
800 		/* Propagate the operation return code if the page write
801 		 * was successful.
802 		 */
803 		if (ret >= 0 && r < 0)
804 			ret = r;
805 	} else {
806 		/* Propagate the phy page selection error code */
807 		ret = oldpage;
808 	}
809 
810 	phy_unlock_mdio_bus(phydev);
811 
812 	return ret;
813 }
814 EXPORT_SYMBOL_GPL(phy_restore_page);
815 
816 /**
817  * phy_read_paged() - Convenience function for reading a paged register
818  * @phydev: a pointer to a &struct phy_device
819  * @page: the page for the phy
820  * @regnum: register number
821  *
822  * Same rules as for phy_read().
823  */
824 int phy_read_paged(struct phy_device *phydev, int page, u32 regnum)
825 {
826 	int ret = 0, oldpage;
827 
828 	oldpage = phy_select_page(phydev, page);
829 	if (oldpage >= 0)
830 		ret = __phy_read(phydev, regnum);
831 
832 	return phy_restore_page(phydev, oldpage, ret);
833 }
834 EXPORT_SYMBOL(phy_read_paged);
835 
836 /**
837  * phy_write_paged() - Convenience function for writing a paged register
838  * @phydev: a pointer to a &struct phy_device
839  * @page: the page for the phy
840  * @regnum: register number
841  * @val: value to write
842  *
843  * Same rules as for phy_write().
844  */
845 int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val)
846 {
847 	int ret = 0, oldpage;
848 
849 	oldpage = phy_select_page(phydev, page);
850 	if (oldpage >= 0)
851 		ret = __phy_write(phydev, regnum, val);
852 
853 	return phy_restore_page(phydev, oldpage, ret);
854 }
855 EXPORT_SYMBOL(phy_write_paged);
856 
857 /**
858  * phy_modify_paged_changed() - Function for modifying a paged register
859  * @phydev: a pointer to a &struct phy_device
860  * @page: the page for the phy
861  * @regnum: register number
862  * @mask: bit mask of bits to clear
863  * @set: bit mask of bits to set
864  *
865  * Returns negative errno, 0 if there was no change, and 1 in case of change
866  */
867 int phy_modify_paged_changed(struct phy_device *phydev, int page, u32 regnum,
868 			     u16 mask, u16 set)
869 {
870 	int ret = 0, oldpage;
871 
872 	oldpage = phy_select_page(phydev, page);
873 	if (oldpage >= 0)
874 		ret = __phy_modify_changed(phydev, regnum, mask, set);
875 
876 	return phy_restore_page(phydev, oldpage, ret);
877 }
878 EXPORT_SYMBOL(phy_modify_paged_changed);
879 
880 /**
881  * phy_modify_paged() - Convenience function for modifying a paged register
882  * @phydev: a pointer to a &struct phy_device
883  * @page: the page for the phy
884  * @regnum: register number
885  * @mask: bit mask of bits to clear
886  * @set: bit mask of bits to set
887  *
888  * Same rules as for phy_read() and phy_write().
889  */
890 int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
891 		     u16 mask, u16 set)
892 {
893 	int ret = phy_modify_paged_changed(phydev, page, regnum, mask, set);
894 
895 	return ret < 0 ? ret : 0;
896 }
897 EXPORT_SYMBOL(phy_modify_paged);
898