xref: /linux/drivers/net/phy/phy.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
1 /*
2  * drivers/net/phy/phy.c
3  *
4  * Framework for configuring and reading PHY devices
5  * Based on code in sungem_phy.c and gianfar_phy.c
6  *
7  * Author: Andy Fleming
8  *
9  * Copyright (c) 2004 Freescale Semiconductor, Inc.
10  * Copyright (c) 2006, 2007  Maciej W. Rozycki
11  *
12  * This program is free software; you can redistribute  it and/or modify it
13  * under  the terms of  the GNU General  Public License as published by the
14  * Free Software Foundation;  either version 2 of the  License, or (at your
15  * option) any later version.
16  *
17  */
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/unistd.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <linux/netdevice.h>
27 #include <linux/etherdevice.h>
28 #include <linux/skbuff.h>
29 #include <linux/mm.h>
30 #include <linux/module.h>
31 #include <linux/mii.h>
32 #include <linux/ethtool.h>
33 #include <linux/phy.h>
34 #include <linux/timer.h>
35 #include <linux/workqueue.h>
36 
37 #include <asm/atomic.h>
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/uaccess.h>
41 
42 /**
43  * phy_print_status - Convenience function to print out the current phy status
44  * @phydev: the phy_device struct
45  */
46 void phy_print_status(struct phy_device *phydev)
47 {
48 	pr_info("PHY: %s - Link is %s", dev_name(&phydev->dev),
49 			phydev->link ? "Up" : "Down");
50 	if (phydev->link)
51 		printk(" - %d/%s", phydev->speed,
52 				DUPLEX_FULL == phydev->duplex ?
53 				"Full" : "Half");
54 
55 	printk("\n");
56 }
57 EXPORT_SYMBOL(phy_print_status);
58 
59 
60 /**
61  * phy_clear_interrupt - Ack the phy device's interrupt
62  * @phydev: the phy_device struct
63  *
64  * If the @phydev driver has an ack_interrupt function, call it to
65  * ack and clear the phy device's interrupt.
66  *
67  * Returns 0 on success on < 0 on error.
68  */
69 int phy_clear_interrupt(struct phy_device *phydev)
70 {
71 	int err = 0;
72 
73 	if (phydev->drv->ack_interrupt)
74 		err = phydev->drv->ack_interrupt(phydev);
75 
76 	return err;
77 }
78 
79 /**
80  * phy_config_interrupt - configure the PHY device for the requested interrupts
81  * @phydev: the phy_device struct
82  * @interrupts: interrupt flags to configure for this @phydev
83  *
84  * Returns 0 on success on < 0 on error.
85  */
86 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
87 {
88 	int err = 0;
89 
90 	phydev->interrupts = interrupts;
91 	if (phydev->drv->config_intr)
92 		err = phydev->drv->config_intr(phydev);
93 
94 	return err;
95 }
96 
97 
98 /**
99  * phy_aneg_done - return auto-negotiation status
100  * @phydev: target phy_device struct
101  *
102  * Description: Reads the status register and returns 0 either if
103  *   auto-negotiation is incomplete, or if there was an error.
104  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
105  */
106 static inline int phy_aneg_done(struct phy_device *phydev)
107 {
108 	int retval;
109 
110 	retval = phy_read(phydev, MII_BMSR);
111 
112 	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
113 }
114 
115 /* A structure for mapping a particular speed and duplex
116  * combination to a particular SUPPORTED and ADVERTISED value */
117 struct phy_setting {
118 	int speed;
119 	int duplex;
120 	u32 setting;
121 };
122 
123 /* A mapping of all SUPPORTED settings to speed/duplex */
124 static const struct phy_setting settings[] = {
125 	{
126 		.speed = 10000,
127 		.duplex = DUPLEX_FULL,
128 		.setting = SUPPORTED_10000baseT_Full,
129 	},
130 	{
131 		.speed = SPEED_1000,
132 		.duplex = DUPLEX_FULL,
133 		.setting = SUPPORTED_1000baseT_Full,
134 	},
135 	{
136 		.speed = SPEED_1000,
137 		.duplex = DUPLEX_HALF,
138 		.setting = SUPPORTED_1000baseT_Half,
139 	},
140 	{
141 		.speed = SPEED_100,
142 		.duplex = DUPLEX_FULL,
143 		.setting = SUPPORTED_100baseT_Full,
144 	},
145 	{
146 		.speed = SPEED_100,
147 		.duplex = DUPLEX_HALF,
148 		.setting = SUPPORTED_100baseT_Half,
149 	},
150 	{
151 		.speed = SPEED_10,
152 		.duplex = DUPLEX_FULL,
153 		.setting = SUPPORTED_10baseT_Full,
154 	},
155 	{
156 		.speed = SPEED_10,
157 		.duplex = DUPLEX_HALF,
158 		.setting = SUPPORTED_10baseT_Half,
159 	},
160 };
161 
162 #define MAX_NUM_SETTINGS ARRAY_SIZE(settings)
163 
164 /**
165  * phy_find_setting - find a PHY settings array entry that matches speed & duplex
166  * @speed: speed to match
167  * @duplex: duplex to match
168  *
169  * Description: Searches the settings array for the setting which
170  *   matches the desired speed and duplex, and returns the index
171  *   of that setting.  Returns the index of the last setting if
172  *   none of the others match.
173  */
174 static inline int phy_find_setting(int speed, int duplex)
175 {
176 	int idx = 0;
177 
178 	while (idx < ARRAY_SIZE(settings) &&
179 			(settings[idx].speed != speed ||
180 			settings[idx].duplex != duplex))
181 		idx++;
182 
183 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
184 }
185 
186 /**
187  * phy_find_valid - find a PHY setting that matches the requested features mask
188  * @idx: The first index in settings[] to search
189  * @features: A mask of the valid settings
190  *
191  * Description: Returns the index of the first valid setting less
192  *   than or equal to the one pointed to by idx, as determined by
193  *   the mask in features.  Returns the index of the last setting
194  *   if nothing else matches.
195  */
196 static inline int phy_find_valid(int idx, u32 features)
197 {
198 	while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
199 		idx++;
200 
201 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
202 }
203 
204 /**
205  * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
206  * @phydev: the target phy_device struct
207  *
208  * Description: Make sure the PHY is set to supported speeds and
209  *   duplexes.  Drop down by one in this order:  1000/FULL,
210  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
211  */
212 void phy_sanitize_settings(struct phy_device *phydev)
213 {
214 	u32 features = phydev->supported;
215 	int idx;
216 
217 	/* Sanitize settings based on PHY capabilities */
218 	if ((features & SUPPORTED_Autoneg) == 0)
219 		phydev->autoneg = AUTONEG_DISABLE;
220 
221 	idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
222 			features);
223 
224 	phydev->speed = settings[idx].speed;
225 	phydev->duplex = settings[idx].duplex;
226 }
227 EXPORT_SYMBOL(phy_sanitize_settings);
228 
229 /**
230  * phy_ethtool_sset - generic ethtool sset function, handles all the details
231  * @phydev: target phy_device struct
232  * @cmd: ethtool_cmd
233  *
234  * A few notes about parameter checking:
235  * - We don't set port or transceiver, so we don't care what they
236  *   were set to.
237  * - phy_start_aneg() will make sure forced settings are sane, and
238  *   choose the next best ones from the ones selected, so we don't
239  *   care if ethtool tries to give us bad values.
240  */
241 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
242 {
243 	if (cmd->phy_address != phydev->addr)
244 		return -EINVAL;
245 
246 	/* We make sure that we don't pass unsupported
247 	 * values in to the PHY */
248 	cmd->advertising &= phydev->supported;
249 
250 	/* Verify the settings we care about. */
251 	if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
252 		return -EINVAL;
253 
254 	if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
255 		return -EINVAL;
256 
257 	if (cmd->autoneg == AUTONEG_DISABLE &&
258 	    ((cmd->speed != SPEED_1000 &&
259 	      cmd->speed != SPEED_100 &&
260 	      cmd->speed != SPEED_10) ||
261 	     (cmd->duplex != DUPLEX_HALF &&
262 	      cmd->duplex != DUPLEX_FULL)))
263 		return -EINVAL;
264 
265 	phydev->autoneg = cmd->autoneg;
266 
267 	phydev->speed = cmd->speed;
268 
269 	phydev->advertising = cmd->advertising;
270 
271 	if (AUTONEG_ENABLE == cmd->autoneg)
272 		phydev->advertising |= ADVERTISED_Autoneg;
273 	else
274 		phydev->advertising &= ~ADVERTISED_Autoneg;
275 
276 	phydev->duplex = cmd->duplex;
277 
278 	/* Restart the PHY */
279 	phy_start_aneg(phydev);
280 
281 	return 0;
282 }
283 EXPORT_SYMBOL(phy_ethtool_sset);
284 
285 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
286 {
287 	cmd->supported = phydev->supported;
288 
289 	cmd->advertising = phydev->advertising;
290 
291 	cmd->speed = phydev->speed;
292 	cmd->duplex = phydev->duplex;
293 	cmd->port = PORT_MII;
294 	cmd->phy_address = phydev->addr;
295 	cmd->transceiver = XCVR_EXTERNAL;
296 	cmd->autoneg = phydev->autoneg;
297 
298 	return 0;
299 }
300 EXPORT_SYMBOL(phy_ethtool_gset);
301 
302 /**
303  * phy_mii_ioctl - generic PHY MII ioctl interface
304  * @phydev: the phy_device struct
305  * @mii_data: MII ioctl data
306  * @cmd: ioctl cmd to execute
307  *
308  * Note that this function is currently incompatible with the
309  * PHYCONTROL layer.  It changes registers without regard to
310  * current state.  Use at own risk.
311  */
312 int phy_mii_ioctl(struct phy_device *phydev,
313 		struct mii_ioctl_data *mii_data, int cmd)
314 {
315 	u16 val = mii_data->val_in;
316 
317 	switch (cmd) {
318 	case SIOCGMIIPHY:
319 		mii_data->phy_id = phydev->addr;
320 		/* fall through */
321 
322 	case SIOCGMIIREG:
323 		mii_data->val_out = phy_read(phydev, mii_data->reg_num);
324 		break;
325 
326 	case SIOCSMIIREG:
327 		if (mii_data->phy_id == phydev->addr) {
328 			switch(mii_data->reg_num) {
329 			case MII_BMCR:
330 				if ((val & (BMCR_RESET|BMCR_ANENABLE)) == 0)
331 					phydev->autoneg = AUTONEG_DISABLE;
332 				else
333 					phydev->autoneg = AUTONEG_ENABLE;
334 				if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
335 					phydev->duplex = DUPLEX_FULL;
336 				else
337 					phydev->duplex = DUPLEX_HALF;
338 				if ((!phydev->autoneg) &&
339 						(val & BMCR_SPEED1000))
340 					phydev->speed = SPEED_1000;
341 				else if ((!phydev->autoneg) &&
342 						(val & BMCR_SPEED100))
343 					phydev->speed = SPEED_100;
344 				break;
345 			case MII_ADVERTISE:
346 				phydev->advertising = val;
347 				break;
348 			default:
349 				/* do nothing */
350 				break;
351 			}
352 		}
353 
354 		phy_write(phydev, mii_data->reg_num, val);
355 
356 		if (mii_data->reg_num == MII_BMCR &&
357 		    val & BMCR_RESET &&
358 		    phydev->drv->config_init) {
359 			phy_scan_fixups(phydev);
360 			phydev->drv->config_init(phydev);
361 		}
362 		break;
363 
364 	default:
365 		return -EOPNOTSUPP;
366 	}
367 
368 	return 0;
369 }
370 EXPORT_SYMBOL(phy_mii_ioctl);
371 
372 /**
373  * phy_start_aneg - start auto-negotiation for this PHY device
374  * @phydev: the phy_device struct
375  *
376  * Description: Sanitizes the settings (if we're not autonegotiating
377  *   them), and then calls the driver's config_aneg function.
378  *   If the PHYCONTROL Layer is operating, we change the state to
379  *   reflect the beginning of Auto-negotiation or forcing.
380  */
381 int phy_start_aneg(struct phy_device *phydev)
382 {
383 	int err;
384 
385 	mutex_lock(&phydev->lock);
386 
387 	if (AUTONEG_DISABLE == phydev->autoneg)
388 		phy_sanitize_settings(phydev);
389 
390 	err = phydev->drv->config_aneg(phydev);
391 
392 	if (err < 0)
393 		goto out_unlock;
394 
395 	if (phydev->state != PHY_HALTED) {
396 		if (AUTONEG_ENABLE == phydev->autoneg) {
397 			phydev->state = PHY_AN;
398 			phydev->link_timeout = PHY_AN_TIMEOUT;
399 		} else {
400 			phydev->state = PHY_FORCING;
401 			phydev->link_timeout = PHY_FORCE_TIMEOUT;
402 		}
403 	}
404 
405 out_unlock:
406 	mutex_unlock(&phydev->lock);
407 	return err;
408 }
409 EXPORT_SYMBOL(phy_start_aneg);
410 
411 
412 static void phy_change(struct work_struct *work);
413 
414 /**
415  * phy_start_machine - start PHY state machine tracking
416  * @phydev: the phy_device struct
417  * @handler: callback function for state change notifications
418  *
419  * Description: The PHY infrastructure can run a state machine
420  *   which tracks whether the PHY is starting up, negotiating,
421  *   etc.  This function starts the timer which tracks the state
422  *   of the PHY.  If you want to be notified when the state changes,
423  *   pass in the callback @handler, otherwise, pass NULL.  If you
424  *   want to maintain your own state machine, do not call this
425  *   function.
426  */
427 void phy_start_machine(struct phy_device *phydev,
428 		void (*handler)(struct net_device *))
429 {
430 	phydev->adjust_state = handler;
431 
432 	schedule_delayed_work(&phydev->state_queue, HZ);
433 }
434 
435 /**
436  * phy_stop_machine - stop the PHY state machine tracking
437  * @phydev: target phy_device struct
438  *
439  * Description: Stops the state machine timer, sets the state to UP
440  *   (unless it wasn't up yet). This function must be called BEFORE
441  *   phy_detach.
442  */
443 void phy_stop_machine(struct phy_device *phydev)
444 {
445 	cancel_delayed_work_sync(&phydev->state_queue);
446 
447 	mutex_lock(&phydev->lock);
448 	if (phydev->state > PHY_UP)
449 		phydev->state = PHY_UP;
450 	mutex_unlock(&phydev->lock);
451 
452 	phydev->adjust_state = NULL;
453 }
454 
455 /**
456  * phy_force_reduction - reduce PHY speed/duplex settings by one step
457  * @phydev: target phy_device struct
458  *
459  * Description: Reduces the speed/duplex settings by one notch,
460  *   in this order--
461  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
462  *   The function bottoms out at 10/HALF.
463  */
464 static void phy_force_reduction(struct phy_device *phydev)
465 {
466 	int idx;
467 
468 	idx = phy_find_setting(phydev->speed, phydev->duplex);
469 
470 	idx++;
471 
472 	idx = phy_find_valid(idx, phydev->supported);
473 
474 	phydev->speed = settings[idx].speed;
475 	phydev->duplex = settings[idx].duplex;
476 
477 	pr_info("Trying %d/%s\n", phydev->speed,
478 			DUPLEX_FULL == phydev->duplex ?
479 			"FULL" : "HALF");
480 }
481 
482 
483 /**
484  * phy_error - enter HALTED state for this PHY device
485  * @phydev: target phy_device struct
486  *
487  * Moves the PHY to the HALTED state in response to a read
488  * or write error, and tells the controller the link is down.
489  * Must not be called from interrupt context, or while the
490  * phydev->lock is held.
491  */
492 static void phy_error(struct phy_device *phydev)
493 {
494 	mutex_lock(&phydev->lock);
495 	phydev->state = PHY_HALTED;
496 	mutex_unlock(&phydev->lock);
497 }
498 
499 /**
500  * phy_interrupt - PHY interrupt handler
501  * @irq: interrupt line
502  * @phy_dat: phy_device pointer
503  *
504  * Description: When a PHY interrupt occurs, the handler disables
505  * interrupts, and schedules a work task to clear the interrupt.
506  */
507 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
508 {
509 	struct phy_device *phydev = phy_dat;
510 
511 	if (PHY_HALTED == phydev->state)
512 		return IRQ_NONE;		/* It can't be ours.  */
513 
514 	/* The MDIO bus is not allowed to be written in interrupt
515 	 * context, so we need to disable the irq here.  A work
516 	 * queue will write the PHY to disable and clear the
517 	 * interrupt, and then reenable the irq line. */
518 	disable_irq_nosync(irq);
519 	atomic_inc(&phydev->irq_disable);
520 
521 	schedule_work(&phydev->phy_queue);
522 
523 	return IRQ_HANDLED;
524 }
525 
526 /**
527  * phy_enable_interrupts - Enable the interrupts from the PHY side
528  * @phydev: target phy_device struct
529  */
530 int phy_enable_interrupts(struct phy_device *phydev)
531 {
532 	int err;
533 
534 	err = phy_clear_interrupt(phydev);
535 
536 	if (err < 0)
537 		return err;
538 
539 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
540 
541 	return err;
542 }
543 EXPORT_SYMBOL(phy_enable_interrupts);
544 
545 /**
546  * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
547  * @phydev: target phy_device struct
548  */
549 int phy_disable_interrupts(struct phy_device *phydev)
550 {
551 	int err;
552 
553 	/* Disable PHY interrupts */
554 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
555 
556 	if (err)
557 		goto phy_err;
558 
559 	/* Clear the interrupt */
560 	err = phy_clear_interrupt(phydev);
561 
562 	if (err)
563 		goto phy_err;
564 
565 	return 0;
566 
567 phy_err:
568 	phy_error(phydev);
569 
570 	return err;
571 }
572 EXPORT_SYMBOL(phy_disable_interrupts);
573 
574 /**
575  * phy_start_interrupts - request and enable interrupts for a PHY device
576  * @phydev: target phy_device struct
577  *
578  * Description: Request the interrupt for the given PHY.
579  *   If this fails, then we set irq to PHY_POLL.
580  *   Otherwise, we enable the interrupts in the PHY.
581  *   This should only be called with a valid IRQ number.
582  *   Returns 0 on success or < 0 on error.
583  */
584 int phy_start_interrupts(struct phy_device *phydev)
585 {
586 	int err = 0;
587 
588 	INIT_WORK(&phydev->phy_queue, phy_change);
589 
590 	atomic_set(&phydev->irq_disable, 0);
591 	if (request_irq(phydev->irq, phy_interrupt,
592 				IRQF_SHARED,
593 				"phy_interrupt",
594 				phydev) < 0) {
595 		printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
596 				phydev->bus->name,
597 				phydev->irq);
598 		phydev->irq = PHY_POLL;
599 		return 0;
600 	}
601 
602 	err = phy_enable_interrupts(phydev);
603 
604 	return err;
605 }
606 EXPORT_SYMBOL(phy_start_interrupts);
607 
608 /**
609  * phy_stop_interrupts - disable interrupts from a PHY device
610  * @phydev: target phy_device struct
611  */
612 int phy_stop_interrupts(struct phy_device *phydev)
613 {
614 	int err;
615 
616 	err = phy_disable_interrupts(phydev);
617 
618 	if (err)
619 		phy_error(phydev);
620 
621 	free_irq(phydev->irq, phydev);
622 
623 	/*
624 	 * Cannot call flush_scheduled_work() here as desired because
625 	 * of rtnl_lock(), but we do not really care about what would
626 	 * be done, except from enable_irq(), so cancel any work
627 	 * possibly pending and take care of the matter below.
628 	 */
629 	cancel_work_sync(&phydev->phy_queue);
630 	/*
631 	 * If work indeed has been cancelled, disable_irq() will have
632 	 * been left unbalanced from phy_interrupt() and enable_irq()
633 	 * has to be called so that other devices on the line work.
634 	 */
635 	while (atomic_dec_return(&phydev->irq_disable) >= 0)
636 		enable_irq(phydev->irq);
637 
638 	return err;
639 }
640 EXPORT_SYMBOL(phy_stop_interrupts);
641 
642 
643 /**
644  * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
645  * @work: work_struct that describes the work to be done
646  */
647 static void phy_change(struct work_struct *work)
648 {
649 	int err;
650 	struct phy_device *phydev =
651 		container_of(work, struct phy_device, phy_queue);
652 
653 	if (phydev->drv->did_interrupt &&
654 	    !phydev->drv->did_interrupt(phydev))
655 		goto ignore;
656 
657 	err = phy_disable_interrupts(phydev);
658 
659 	if (err)
660 		goto phy_err;
661 
662 	mutex_lock(&phydev->lock);
663 	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
664 		phydev->state = PHY_CHANGELINK;
665 	mutex_unlock(&phydev->lock);
666 
667 	atomic_dec(&phydev->irq_disable);
668 	enable_irq(phydev->irq);
669 
670 	/* Reenable interrupts */
671 	if (PHY_HALTED != phydev->state)
672 		err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
673 
674 	if (err)
675 		goto irq_enable_err;
676 
677 	/* reschedule state queue work to run as soon as possible */
678 	cancel_delayed_work_sync(&phydev->state_queue);
679 	schedule_delayed_work(&phydev->state_queue, 0);
680 
681 	return;
682 
683 ignore:
684 	atomic_dec(&phydev->irq_disable);
685 	enable_irq(phydev->irq);
686 	return;
687 
688 irq_enable_err:
689 	disable_irq(phydev->irq);
690 	atomic_inc(&phydev->irq_disable);
691 phy_err:
692 	phy_error(phydev);
693 }
694 
695 /**
696  * phy_stop - Bring down the PHY link, and stop checking the status
697  * @phydev: target phy_device struct
698  */
699 void phy_stop(struct phy_device *phydev)
700 {
701 	mutex_lock(&phydev->lock);
702 
703 	if (PHY_HALTED == phydev->state)
704 		goto out_unlock;
705 
706 	if (phydev->irq != PHY_POLL) {
707 		/* Disable PHY Interrupts */
708 		phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
709 
710 		/* Clear any pending interrupts */
711 		phy_clear_interrupt(phydev);
712 	}
713 
714 	phydev->state = PHY_HALTED;
715 
716 out_unlock:
717 	mutex_unlock(&phydev->lock);
718 
719 	/*
720 	 * Cannot call flush_scheduled_work() here as desired because
721 	 * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
722 	 * will not reenable interrupts.
723 	 */
724 }
725 
726 
727 /**
728  * phy_start - start or restart a PHY device
729  * @phydev: target phy_device struct
730  *
731  * Description: Indicates the attached device's readiness to
732  *   handle PHY-related work.  Used during startup to start the
733  *   PHY, and after a call to phy_stop() to resume operation.
734  *   Also used to indicate the MDIO bus has cleared an error
735  *   condition.
736  */
737 void phy_start(struct phy_device *phydev)
738 {
739 	mutex_lock(&phydev->lock);
740 
741 	switch (phydev->state) {
742 		case PHY_STARTING:
743 			phydev->state = PHY_PENDING;
744 			break;
745 		case PHY_READY:
746 			phydev->state = PHY_UP;
747 			break;
748 		case PHY_HALTED:
749 			phydev->state = PHY_RESUMING;
750 		default:
751 			break;
752 	}
753 	mutex_unlock(&phydev->lock);
754 }
755 EXPORT_SYMBOL(phy_stop);
756 EXPORT_SYMBOL(phy_start);
757 
758 /**
759  * phy_state_machine - Handle the state machine
760  * @work: work_struct that describes the work to be done
761  */
762 void phy_state_machine(struct work_struct *work)
763 {
764 	struct delayed_work *dwork = to_delayed_work(work);
765 	struct phy_device *phydev =
766 			container_of(dwork, struct phy_device, state_queue);
767 	int needs_aneg = 0;
768 	int err = 0;
769 
770 	mutex_lock(&phydev->lock);
771 
772 	if (phydev->adjust_state)
773 		phydev->adjust_state(phydev->attached_dev);
774 
775 	switch(phydev->state) {
776 		case PHY_DOWN:
777 		case PHY_STARTING:
778 		case PHY_READY:
779 		case PHY_PENDING:
780 			break;
781 		case PHY_UP:
782 			needs_aneg = 1;
783 
784 			phydev->link_timeout = PHY_AN_TIMEOUT;
785 
786 			break;
787 		case PHY_AN:
788 			err = phy_read_status(phydev);
789 
790 			if (err < 0)
791 				break;
792 
793 			/* If the link is down, give up on
794 			 * negotiation for now */
795 			if (!phydev->link) {
796 				phydev->state = PHY_NOLINK;
797 				netif_carrier_off(phydev->attached_dev);
798 				phydev->adjust_link(phydev->attached_dev);
799 				break;
800 			}
801 
802 			/* Check if negotiation is done.  Break
803 			 * if there's an error */
804 			err = phy_aneg_done(phydev);
805 			if (err < 0)
806 				break;
807 
808 			/* If AN is done, we're running */
809 			if (err > 0) {
810 				phydev->state = PHY_RUNNING;
811 				netif_carrier_on(phydev->attached_dev);
812 				phydev->adjust_link(phydev->attached_dev);
813 
814 			} else if (0 == phydev->link_timeout--) {
815 				int idx;
816 
817 				needs_aneg = 1;
818 				/* If we have the magic_aneg bit,
819 				 * we try again */
820 				if (phydev->drv->flags & PHY_HAS_MAGICANEG)
821 					break;
822 
823 				/* The timer expired, and we still
824 				 * don't have a setting, so we try
825 				 * forcing it until we find one that
826 				 * works, starting from the fastest speed,
827 				 * and working our way down */
828 				idx = phy_find_valid(0, phydev->supported);
829 
830 				phydev->speed = settings[idx].speed;
831 				phydev->duplex = settings[idx].duplex;
832 
833 				phydev->autoneg = AUTONEG_DISABLE;
834 
835 				pr_info("Trying %d/%s\n", phydev->speed,
836 						DUPLEX_FULL ==
837 						phydev->duplex ?
838 						"FULL" : "HALF");
839 			}
840 			break;
841 		case PHY_NOLINK:
842 			err = phy_read_status(phydev);
843 
844 			if (err)
845 				break;
846 
847 			if (phydev->link) {
848 				phydev->state = PHY_RUNNING;
849 				netif_carrier_on(phydev->attached_dev);
850 				phydev->adjust_link(phydev->attached_dev);
851 			}
852 			break;
853 		case PHY_FORCING:
854 			err = genphy_update_link(phydev);
855 
856 			if (err)
857 				break;
858 
859 			if (phydev->link) {
860 				phydev->state = PHY_RUNNING;
861 				netif_carrier_on(phydev->attached_dev);
862 			} else {
863 				if (0 == phydev->link_timeout--) {
864 					phy_force_reduction(phydev);
865 					needs_aneg = 1;
866 				}
867 			}
868 
869 			phydev->adjust_link(phydev->attached_dev);
870 			break;
871 		case PHY_RUNNING:
872 			/* Only register a CHANGE if we are
873 			 * polling */
874 			if (PHY_POLL == phydev->irq)
875 				phydev->state = PHY_CHANGELINK;
876 			break;
877 		case PHY_CHANGELINK:
878 			err = phy_read_status(phydev);
879 
880 			if (err)
881 				break;
882 
883 			if (phydev->link) {
884 				phydev->state = PHY_RUNNING;
885 				netif_carrier_on(phydev->attached_dev);
886 			} else {
887 				phydev->state = PHY_NOLINK;
888 				netif_carrier_off(phydev->attached_dev);
889 			}
890 
891 			phydev->adjust_link(phydev->attached_dev);
892 
893 			if (PHY_POLL != phydev->irq)
894 				err = phy_config_interrupt(phydev,
895 						PHY_INTERRUPT_ENABLED);
896 			break;
897 		case PHY_HALTED:
898 			if (phydev->link) {
899 				phydev->link = 0;
900 				netif_carrier_off(phydev->attached_dev);
901 				phydev->adjust_link(phydev->attached_dev);
902 			}
903 			break;
904 		case PHY_RESUMING:
905 
906 			err = phy_clear_interrupt(phydev);
907 
908 			if (err)
909 				break;
910 
911 			err = phy_config_interrupt(phydev,
912 					PHY_INTERRUPT_ENABLED);
913 
914 			if (err)
915 				break;
916 
917 			if (AUTONEG_ENABLE == phydev->autoneg) {
918 				err = phy_aneg_done(phydev);
919 				if (err < 0)
920 					break;
921 
922 				/* err > 0 if AN is done.
923 				 * Otherwise, it's 0, and we're
924 				 * still waiting for AN */
925 				if (err > 0) {
926 					err = phy_read_status(phydev);
927 					if (err)
928 						break;
929 
930 					if (phydev->link) {
931 						phydev->state = PHY_RUNNING;
932 						netif_carrier_on(phydev->attached_dev);
933 					} else
934 						phydev->state = PHY_NOLINK;
935 					phydev->adjust_link(phydev->attached_dev);
936 				} else {
937 					phydev->state = PHY_AN;
938 					phydev->link_timeout = PHY_AN_TIMEOUT;
939 				}
940 			} else {
941 				err = phy_read_status(phydev);
942 				if (err)
943 					break;
944 
945 				if (phydev->link) {
946 					phydev->state = PHY_RUNNING;
947 					netif_carrier_on(phydev->attached_dev);
948 				} else
949 					phydev->state = PHY_NOLINK;
950 				phydev->adjust_link(phydev->attached_dev);
951 			}
952 			break;
953 	}
954 
955 	mutex_unlock(&phydev->lock);
956 
957 	if (needs_aneg)
958 		err = phy_start_aneg(phydev);
959 
960 	if (err < 0)
961 		phy_error(phydev);
962 
963 	schedule_delayed_work(&phydev->state_queue, PHY_STATE_TIME * HZ);
964 }
965