xref: /linux/drivers/net/phy/phy_device.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /*
2  * drivers/net/phy/phy_device.c
3  *
4  * Framework for finding and configuring PHYs.
5  * Also contains generic PHY driver
6  *
7  * Author: Andy Fleming
8  *
9  * Copyright (c) 2004 Freescale Semiconductor, Inc.
10  *
11  * This program is free software; you can redistribute  it and/or modify it
12  * under  the terms of  the GNU General  Public License as published by the
13  * Free Software Foundation;  either version 2 of the  License, or (at your
14  * option) any later version.
15  *
16  */
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/errno.h>
20 #include <linux/unistd.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
23 #include <linux/init.h>
24 #include <linux/delay.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/mm.h>
29 #include <linux/module.h>
30 #include <linux/mii.h>
31 #include <linux/ethtool.h>
32 #include <linux/phy.h>
33 
34 #include <asm/io.h>
35 #include <asm/irq.h>
36 #include <asm/uaccess.h>
37 
38 MODULE_DESCRIPTION("PHY library");
39 MODULE_AUTHOR("Andy Fleming");
40 MODULE_LICENSE("GPL");
41 
42 static struct phy_driver genphy_driver;
43 extern int mdio_bus_init(void);
44 extern void mdio_bus_exit(void);
45 
46 void phy_device_free(struct phy_device *phydev)
47 {
48 	kfree(phydev);
49 }
50 
51 static void phy_device_release(struct device *dev)
52 {
53 	phy_device_free(to_phy_device(dev));
54 }
55 
56 struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
57 {
58 	struct phy_device *dev;
59 	/* We allocate the device, and initialize the
60 	 * default values */
61 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
62 
63 	if (NULL == dev)
64 		return (struct phy_device*) PTR_ERR((void*)-ENOMEM);
65 
66 	dev->dev.release = phy_device_release;
67 
68 	dev->speed = 0;
69 	dev->duplex = -1;
70 	dev->pause = dev->asym_pause = 0;
71 	dev->link = 1;
72 	dev->interface = PHY_INTERFACE_MODE_GMII;
73 
74 	dev->autoneg = AUTONEG_ENABLE;
75 
76 	dev->addr = addr;
77 	dev->phy_id = phy_id;
78 	dev->bus = bus;
79 
80 	dev->state = PHY_DOWN;
81 
82 	mutex_init(&dev->lock);
83 
84 	return dev;
85 }
86 EXPORT_SYMBOL(phy_device_create);
87 
88 /**
89  * get_phy_device - reads the specified PHY device and returns its @phy_device struct
90  * @bus: the target MII bus
91  * @addr: PHY address on the MII bus
92  *
93  * Description: Reads the ID registers of the PHY at @addr on the
94  *   @bus, then allocates and returns the phy_device to represent it.
95  */
96 struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
97 {
98 	int phy_reg;
99 	u32 phy_id;
100 	struct phy_device *dev = NULL;
101 
102 	/* Grab the bits from PHYIR1, and put them
103 	 * in the upper half */
104 	phy_reg = bus->read(bus, addr, MII_PHYSID1);
105 
106 	if (phy_reg < 0)
107 		return ERR_PTR(phy_reg);
108 
109 	phy_id = (phy_reg & 0xffff) << 16;
110 
111 	/* Grab the bits from PHYIR2, and put them in the lower half */
112 	phy_reg = bus->read(bus, addr, MII_PHYSID2);
113 
114 	if (phy_reg < 0)
115 		return ERR_PTR(phy_reg);
116 
117 	phy_id |= (phy_reg & 0xffff);
118 
119 	/* If the phy_id is all Fs, there is no device there */
120 	if (0xffffffff == phy_id)
121 		return NULL;
122 
123 	dev = phy_device_create(bus, addr, phy_id);
124 
125 	return dev;
126 }
127 
128 /**
129  * phy_prepare_link - prepares the PHY layer to monitor link status
130  * @phydev: target phy_device struct
131  * @handler: callback function for link status change notifications
132  *
133  * Description: Tells the PHY infrastructure to handle the
134  *   gory details on monitoring link status (whether through
135  *   polling or an interrupt), and to call back to the
136  *   connected device driver when the link status changes.
137  *   If you want to monitor your own link state, don't call
138  *   this function.
139  */
140 void phy_prepare_link(struct phy_device *phydev,
141 		void (*handler)(struct net_device *))
142 {
143 	phydev->adjust_link = handler;
144 }
145 
146 /**
147  * phy_connect - connect an ethernet device to a PHY device
148  * @dev: the network device to connect
149  * @phy_id: the PHY device to connect
150  * @handler: callback function for state change notifications
151  * @flags: PHY device's dev_flags
152  * @interface: PHY device's interface
153  *
154  * Description: Convenience function for connecting ethernet
155  *   devices to PHY devices.  The default behavior is for
156  *   the PHY infrastructure to handle everything, and only notify
157  *   the connected driver when the link status changes.  If you
158  *   don't want, or can't use the provided functionality, you may
159  *   choose to call only the subset of functions which provide
160  *   the desired functionality.
161  */
162 struct phy_device * phy_connect(struct net_device *dev, const char *phy_id,
163 		void (*handler)(struct net_device *), u32 flags,
164 		phy_interface_t interface)
165 {
166 	struct phy_device *phydev;
167 
168 	phydev = phy_attach(dev, phy_id, flags, interface);
169 
170 	if (IS_ERR(phydev))
171 		return phydev;
172 
173 	phy_prepare_link(phydev, handler);
174 
175 	phy_start_machine(phydev, NULL);
176 
177 	if (phydev->irq > 0)
178 		phy_start_interrupts(phydev);
179 
180 	return phydev;
181 }
182 EXPORT_SYMBOL(phy_connect);
183 
184 /**
185  * phy_disconnect - disable interrupts, stop state machine, and detach a PHY device
186  * @phydev: target phy_device struct
187  */
188 void phy_disconnect(struct phy_device *phydev)
189 {
190 	if (phydev->irq > 0)
191 		phy_stop_interrupts(phydev);
192 
193 	phy_stop_machine(phydev);
194 
195 	phydev->adjust_link = NULL;
196 
197 	phy_detach(phydev);
198 }
199 EXPORT_SYMBOL(phy_disconnect);
200 
201 static int phy_compare_id(struct device *dev, void *data)
202 {
203 	return strcmp((char *)data, dev->bus_id) ? 0 : 1;
204 }
205 
206 /**
207  * phy_attach - attach a network device to a particular PHY device
208  * @dev: network device to attach
209  * @phy_id: PHY device to attach
210  * @flags: PHY device's dev_flags
211  * @interface: PHY device's interface
212  *
213  * Description: Called by drivers to attach to a particular PHY
214  *     device. The phy_device is found, and properly hooked up
215  *     to the phy_driver.  If no driver is attached, then the
216  *     genphy_driver is used.  The phy_device is given a ptr to
217  *     the attaching device, and given a callback for link status
218  *     change.  The phy_device is returned to the attaching driver.
219  */
220 struct phy_device *phy_attach(struct net_device *dev,
221 		const char *phy_id, u32 flags, phy_interface_t interface)
222 {
223 	struct bus_type *bus = &mdio_bus_type;
224 	struct phy_device *phydev;
225 	struct device *d;
226 
227 	/* Search the list of PHY devices on the mdio bus for the
228 	 * PHY with the requested name */
229 	d = bus_find_device(bus, NULL, (void *)phy_id, phy_compare_id);
230 
231 	if (d) {
232 		phydev = to_phy_device(d);
233 	} else {
234 		printk(KERN_ERR "%s not found\n", phy_id);
235 		return ERR_PTR(-ENODEV);
236 	}
237 
238 	/* Assume that if there is no driver, that it doesn't
239 	 * exist, and we should use the genphy driver. */
240 	if (NULL == d->driver) {
241 		int err;
242 		d->driver = &genphy_driver.driver;
243 
244 		err = d->driver->probe(d);
245 		if (err >= 0)
246 			err = device_bind_driver(d);
247 
248 		if (err)
249 			return ERR_PTR(err);
250 	}
251 
252 	if (phydev->attached_dev) {
253 		printk(KERN_ERR "%s: %s already attached\n",
254 				dev->name, phy_id);
255 		return ERR_PTR(-EBUSY);
256 	}
257 
258 	phydev->attached_dev = dev;
259 
260 	phydev->dev_flags = flags;
261 
262 	phydev->interface = interface;
263 
264 	/* Do initial configuration here, now that
265 	 * we have certain key parameters
266 	 * (dev_flags and interface) */
267 	if (phydev->drv->config_init) {
268 		int err;
269 
270 		err = phydev->drv->config_init(phydev);
271 
272 		if (err < 0)
273 			return ERR_PTR(err);
274 	}
275 
276 	return phydev;
277 }
278 EXPORT_SYMBOL(phy_attach);
279 
280 /**
281  * phy_detach - detach a PHY device from its network device
282  * @phydev: target phy_device struct
283  */
284 void phy_detach(struct phy_device *phydev)
285 {
286 	phydev->attached_dev = NULL;
287 
288 	/* If the device had no specific driver before (i.e. - it
289 	 * was using the generic driver), we unbind the device
290 	 * from the generic driver so that there's a chance a
291 	 * real driver could be loaded */
292 	if (phydev->dev.driver == &genphy_driver.driver)
293 		device_release_driver(&phydev->dev);
294 }
295 EXPORT_SYMBOL(phy_detach);
296 
297 
298 /* Generic PHY support and helper functions */
299 
300 /**
301  * genphy_config_advert - sanitize and advertise auto-negotation parameters
302  * @phydev: target phy_device struct
303  *
304  * Description: Writes MII_ADVERTISE with the appropriate values,
305  *   after sanitizing the values to make sure we only advertise
306  *   what is supported.
307  */
308 int genphy_config_advert(struct phy_device *phydev)
309 {
310 	u32 advertise;
311 	int adv;
312 	int err;
313 
314 	/* Only allow advertising what
315 	 * this PHY supports */
316 	phydev->advertising &= phydev->supported;
317 	advertise = phydev->advertising;
318 
319 	/* Setup standard advertisement */
320 	adv = phy_read(phydev, MII_ADVERTISE);
321 
322 	if (adv < 0)
323 		return adv;
324 
325 	adv &= ~(ADVERTISE_ALL | ADVERTISE_100BASE4 | ADVERTISE_PAUSE_CAP |
326 		 ADVERTISE_PAUSE_ASYM);
327 	if (advertise & ADVERTISED_10baseT_Half)
328 		adv |= ADVERTISE_10HALF;
329 	if (advertise & ADVERTISED_10baseT_Full)
330 		adv |= ADVERTISE_10FULL;
331 	if (advertise & ADVERTISED_100baseT_Half)
332 		adv |= ADVERTISE_100HALF;
333 	if (advertise & ADVERTISED_100baseT_Full)
334 		adv |= ADVERTISE_100FULL;
335 	if (advertise & ADVERTISED_Pause)
336 		adv |= ADVERTISE_PAUSE_CAP;
337 	if (advertise & ADVERTISED_Asym_Pause)
338 		adv |= ADVERTISE_PAUSE_ASYM;
339 
340 	err = phy_write(phydev, MII_ADVERTISE, adv);
341 
342 	if (err < 0)
343 		return err;
344 
345 	/* Configure gigabit if it's supported */
346 	if (phydev->supported & (SUPPORTED_1000baseT_Half |
347 				SUPPORTED_1000baseT_Full)) {
348 		adv = phy_read(phydev, MII_CTRL1000);
349 
350 		if (adv < 0)
351 			return adv;
352 
353 		adv &= ~(ADVERTISE_1000FULL | ADVERTISE_1000HALF);
354 		if (advertise & SUPPORTED_1000baseT_Half)
355 			adv |= ADVERTISE_1000HALF;
356 		if (advertise & SUPPORTED_1000baseT_Full)
357 			adv |= ADVERTISE_1000FULL;
358 		err = phy_write(phydev, MII_CTRL1000, adv);
359 
360 		if (err < 0)
361 			return err;
362 	}
363 
364 	return adv;
365 }
366 EXPORT_SYMBOL(genphy_config_advert);
367 
368 /**
369  * genphy_setup_forced - configures/forces speed/duplex from @phydev
370  * @phydev: target phy_device struct
371  *
372  * Description: Configures MII_BMCR to force speed/duplex
373  *   to the values in phydev. Assumes that the values are valid.
374  *   Please see phy_sanitize_settings().
375  */
376 int genphy_setup_forced(struct phy_device *phydev)
377 {
378 	int ctl = 0;
379 
380 	phydev->pause = phydev->asym_pause = 0;
381 
382 	if (SPEED_1000 == phydev->speed)
383 		ctl |= BMCR_SPEED1000;
384 	else if (SPEED_100 == phydev->speed)
385 		ctl |= BMCR_SPEED100;
386 
387 	if (DUPLEX_FULL == phydev->duplex)
388 		ctl |= BMCR_FULLDPLX;
389 
390 	ctl = phy_write(phydev, MII_BMCR, ctl);
391 
392 	if (ctl < 0)
393 		return ctl;
394 
395 	/* We just reset the device, so we'd better configure any
396 	 * settings the PHY requires to operate */
397 	if (phydev->drv->config_init)
398 		ctl = phydev->drv->config_init(phydev);
399 
400 	return ctl;
401 }
402 
403 
404 /**
405  * genphy_restart_aneg - Enable and Restart Autonegotiation
406  * @phydev: target phy_device struct
407  */
408 int genphy_restart_aneg(struct phy_device *phydev)
409 {
410 	int ctl;
411 
412 	ctl = phy_read(phydev, MII_BMCR);
413 
414 	if (ctl < 0)
415 		return ctl;
416 
417 	ctl |= (BMCR_ANENABLE | BMCR_ANRESTART);
418 
419 	/* Don't isolate the PHY if we're negotiating */
420 	ctl &= ~(BMCR_ISOLATE);
421 
422 	ctl = phy_write(phydev, MII_BMCR, ctl);
423 
424 	return ctl;
425 }
426 
427 
428 /**
429  * genphy_config_aneg - restart auto-negotiation or write BMCR
430  * @phydev: target phy_device struct
431  *
432  * Description: If auto-negotiation is enabled, we configure the
433  *   advertising, and then restart auto-negotiation.  If it is not
434  *   enabled, then we write the BMCR.
435  */
436 int genphy_config_aneg(struct phy_device *phydev)
437 {
438 	int err = 0;
439 
440 	if (AUTONEG_ENABLE == phydev->autoneg) {
441 		err = genphy_config_advert(phydev);
442 
443 		if (err < 0)
444 			return err;
445 
446 		err = genphy_restart_aneg(phydev);
447 	} else
448 		err = genphy_setup_forced(phydev);
449 
450 	return err;
451 }
452 EXPORT_SYMBOL(genphy_config_aneg);
453 
454 /**
455  * genphy_update_link - update link status in @phydev
456  * @phydev: target phy_device struct
457  *
458  * Description: Update the value in phydev->link to reflect the
459  *   current link value.  In order to do this, we need to read
460  *   the status register twice, keeping the second value.
461  */
462 int genphy_update_link(struct phy_device *phydev)
463 {
464 	int status;
465 
466 	/* Do a fake read */
467 	status = phy_read(phydev, MII_BMSR);
468 
469 	if (status < 0)
470 		return status;
471 
472 	/* Read link and autonegotiation status */
473 	status = phy_read(phydev, MII_BMSR);
474 
475 	if (status < 0)
476 		return status;
477 
478 	if ((status & BMSR_LSTATUS) == 0)
479 		phydev->link = 0;
480 	else
481 		phydev->link = 1;
482 
483 	return 0;
484 }
485 EXPORT_SYMBOL(genphy_update_link);
486 
487 /**
488  * genphy_read_status - check the link status and update current link state
489  * @phydev: target phy_device struct
490  *
491  * Description: Check the link, then figure out the current state
492  *   by comparing what we advertise with what the link partner
493  *   advertises.  Start by checking the gigabit possibilities,
494  *   then move on to 10/100.
495  */
496 int genphy_read_status(struct phy_device *phydev)
497 {
498 	int adv;
499 	int err;
500 	int lpa;
501 	int lpagb = 0;
502 
503 	/* Update the link, but return if there
504 	 * was an error */
505 	err = genphy_update_link(phydev);
506 	if (err)
507 		return err;
508 
509 	if (AUTONEG_ENABLE == phydev->autoneg) {
510 		if (phydev->supported & (SUPPORTED_1000baseT_Half
511 					| SUPPORTED_1000baseT_Full)) {
512 			lpagb = phy_read(phydev, MII_STAT1000);
513 
514 			if (lpagb < 0)
515 				return lpagb;
516 
517 			adv = phy_read(phydev, MII_CTRL1000);
518 
519 			if (adv < 0)
520 				return adv;
521 
522 			lpagb &= adv << 2;
523 		}
524 
525 		lpa = phy_read(phydev, MII_LPA);
526 
527 		if (lpa < 0)
528 			return lpa;
529 
530 		adv = phy_read(phydev, MII_ADVERTISE);
531 
532 		if (adv < 0)
533 			return adv;
534 
535 		lpa &= adv;
536 
537 		phydev->speed = SPEED_10;
538 		phydev->duplex = DUPLEX_HALF;
539 		phydev->pause = phydev->asym_pause = 0;
540 
541 		if (lpagb & (LPA_1000FULL | LPA_1000HALF)) {
542 			phydev->speed = SPEED_1000;
543 
544 			if (lpagb & LPA_1000FULL)
545 				phydev->duplex = DUPLEX_FULL;
546 		} else if (lpa & (LPA_100FULL | LPA_100HALF)) {
547 			phydev->speed = SPEED_100;
548 
549 			if (lpa & LPA_100FULL)
550 				phydev->duplex = DUPLEX_FULL;
551 		} else
552 			if (lpa & LPA_10FULL)
553 				phydev->duplex = DUPLEX_FULL;
554 
555 		if (phydev->duplex == DUPLEX_FULL){
556 			phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;
557 			phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;
558 		}
559 	} else {
560 		int bmcr = phy_read(phydev, MII_BMCR);
561 		if (bmcr < 0)
562 			return bmcr;
563 
564 		if (bmcr & BMCR_FULLDPLX)
565 			phydev->duplex = DUPLEX_FULL;
566 		else
567 			phydev->duplex = DUPLEX_HALF;
568 
569 		if (bmcr & BMCR_SPEED1000)
570 			phydev->speed = SPEED_1000;
571 		else if (bmcr & BMCR_SPEED100)
572 			phydev->speed = SPEED_100;
573 		else
574 			phydev->speed = SPEED_10;
575 
576 		phydev->pause = phydev->asym_pause = 0;
577 	}
578 
579 	return 0;
580 }
581 EXPORT_SYMBOL(genphy_read_status);
582 
583 static int genphy_config_init(struct phy_device *phydev)
584 {
585 	int val;
586 	u32 features;
587 
588 	/* For now, I'll claim that the generic driver supports
589 	 * all possible port types */
590 	features = (SUPPORTED_TP | SUPPORTED_MII
591 			| SUPPORTED_AUI | SUPPORTED_FIBRE |
592 			SUPPORTED_BNC);
593 
594 	/* Do we support autonegotiation? */
595 	val = phy_read(phydev, MII_BMSR);
596 
597 	if (val < 0)
598 		return val;
599 
600 	if (val & BMSR_ANEGCAPABLE)
601 		features |= SUPPORTED_Autoneg;
602 
603 	if (val & BMSR_100FULL)
604 		features |= SUPPORTED_100baseT_Full;
605 	if (val & BMSR_100HALF)
606 		features |= SUPPORTED_100baseT_Half;
607 	if (val & BMSR_10FULL)
608 		features |= SUPPORTED_10baseT_Full;
609 	if (val & BMSR_10HALF)
610 		features |= SUPPORTED_10baseT_Half;
611 
612 	if (val & BMSR_ESTATEN) {
613 		val = phy_read(phydev, MII_ESTATUS);
614 
615 		if (val < 0)
616 			return val;
617 
618 		if (val & ESTATUS_1000_TFULL)
619 			features |= SUPPORTED_1000baseT_Full;
620 		if (val & ESTATUS_1000_THALF)
621 			features |= SUPPORTED_1000baseT_Half;
622 	}
623 
624 	phydev->supported = features;
625 	phydev->advertising = features;
626 
627 	return 0;
628 }
629 
630 
631 /**
632  * phy_probe - probe and init a PHY device
633  * @dev: device to probe and init
634  *
635  * Description: Take care of setting up the phy_device structure,
636  *   set the state to READY (the driver's init function should
637  *   set it to STARTING if needed).
638  */
639 static int phy_probe(struct device *dev)
640 {
641 	struct phy_device *phydev;
642 	struct phy_driver *phydrv;
643 	struct device_driver *drv;
644 	int err = 0;
645 
646 	phydev = to_phy_device(dev);
647 
648 	/* Make sure the driver is held.
649 	 * XXX -- Is this correct? */
650 	drv = get_driver(phydev->dev.driver);
651 	phydrv = to_phy_driver(drv);
652 	phydev->drv = phydrv;
653 
654 	/* Disable the interrupt if the PHY doesn't support it */
655 	if (!(phydrv->flags & PHY_HAS_INTERRUPT))
656 		phydev->irq = PHY_POLL;
657 
658 	mutex_lock(&phydev->lock);
659 
660 	/* Start out supporting everything. Eventually,
661 	 * a controller will attach, and may modify one
662 	 * or both of these values */
663 	phydev->supported = phydrv->features;
664 	phydev->advertising = phydrv->features;
665 
666 	/* Set the state to READY by default */
667 	phydev->state = PHY_READY;
668 
669 	if (phydev->drv->probe)
670 		err = phydev->drv->probe(phydev);
671 
672 	mutex_unlock(&phydev->lock);
673 
674 	return err;
675 
676 }
677 
678 static int phy_remove(struct device *dev)
679 {
680 	struct phy_device *phydev;
681 
682 	phydev = to_phy_device(dev);
683 
684 	mutex_lock(&phydev->lock);
685 	phydev->state = PHY_DOWN;
686 	mutex_unlock(&phydev->lock);
687 
688 	if (phydev->drv->remove)
689 		phydev->drv->remove(phydev);
690 
691 	put_driver(dev->driver);
692 	phydev->drv = NULL;
693 
694 	return 0;
695 }
696 
697 /**
698  * phy_driver_register - register a phy_driver with the PHY layer
699  * @new_driver: new phy_driver to register
700  */
701 int phy_driver_register(struct phy_driver *new_driver)
702 {
703 	int retval;
704 
705 	memset(&new_driver->driver, 0, sizeof(new_driver->driver));
706 	new_driver->driver.name = new_driver->name;
707 	new_driver->driver.bus = &mdio_bus_type;
708 	new_driver->driver.probe = phy_probe;
709 	new_driver->driver.remove = phy_remove;
710 
711 	retval = driver_register(&new_driver->driver);
712 
713 	if (retval) {
714 		printk(KERN_ERR "%s: Error %d in registering driver\n",
715 				new_driver->name, retval);
716 
717 		return retval;
718 	}
719 
720 	pr_debug("%s: Registered new driver\n", new_driver->name);
721 
722 	return 0;
723 }
724 EXPORT_SYMBOL(phy_driver_register);
725 
726 void phy_driver_unregister(struct phy_driver *drv)
727 {
728 	driver_unregister(&drv->driver);
729 }
730 EXPORT_SYMBOL(phy_driver_unregister);
731 
732 static struct phy_driver genphy_driver = {
733 	.phy_id		= 0xffffffff,
734 	.phy_id_mask	= 0xffffffff,
735 	.name		= "Generic PHY",
736 	.config_init	= genphy_config_init,
737 	.features	= 0,
738 	.config_aneg	= genphy_config_aneg,
739 	.read_status	= genphy_read_status,
740 	.driver		= {.owner= THIS_MODULE, },
741 };
742 
743 static int __init phy_init(void)
744 {
745 	int rc;
746 
747 	rc = mdio_bus_init();
748 	if (rc)
749 		return rc;
750 
751 	rc = phy_driver_register(&genphy_driver);
752 	if (rc)
753 		mdio_bus_exit();
754 
755 	return rc;
756 }
757 
758 static void __exit phy_exit(void)
759 {
760 	phy_driver_unregister(&genphy_driver);
761 	mdio_bus_exit();
762 }
763 
764 subsys_initcall(phy_init);
765 module_exit(phy_exit);
766