xref: /openbmc/linux/drivers/net/phy/phy.c (revision 92ed1a76)
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/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 #include <linux/timer.h>
34 #include <linux/workqueue.h>
35 
36 #include <asm/atomic.h>
37 #include <asm/io.h>
38 #include <asm/irq.h>
39 #include <asm/uaccess.h>
40 
41 /**
42  * phy_print_status - Convenience function to print out the current phy status
43  * @phydev: the phy_device struct
44  */
45 void phy_print_status(struct phy_device *phydev)
46 {
47 	pr_info("PHY: %s - Link is %s", dev_name(&phydev->dev),
48 			phydev->link ? "Up" : "Down");
49 	if (phydev->link)
50 		printk(KERN_CONT " - %d/%s", phydev->speed,
51 				DUPLEX_FULL == phydev->duplex ?
52 				"Full" : "Half");
53 
54 	printk(KERN_CONT "\n");
55 }
56 EXPORT_SYMBOL(phy_print_status);
57 
58 
59 /**
60  * phy_clear_interrupt - Ack the phy device's interrupt
61  * @phydev: the phy_device struct
62  *
63  * If the @phydev driver has an ack_interrupt function, call it to
64  * ack and clear the phy device's interrupt.
65  *
66  * Returns 0 on success on < 0 on error.
67  */
68 static int phy_clear_interrupt(struct phy_device *phydev)
69 {
70 	int err = 0;
71 
72 	if (phydev->drv->ack_interrupt)
73 		err = phydev->drv->ack_interrupt(phydev);
74 
75 	return err;
76 }
77 
78 /**
79  * phy_config_interrupt - configure the PHY device for the requested interrupts
80  * @phydev: the phy_device struct
81  * @interrupts: interrupt flags to configure for this @phydev
82  *
83  * Returns 0 on success on < 0 on error.
84  */
85 static int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
86 {
87 	int err = 0;
88 
89 	phydev->interrupts = interrupts;
90 	if (phydev->drv->config_intr)
91 		err = phydev->drv->config_intr(phydev);
92 
93 	return err;
94 }
95 
96 
97 /**
98  * phy_aneg_done - return auto-negotiation status
99  * @phydev: target phy_device struct
100  *
101  * Description: Reads the status register and returns 0 either if
102  *   auto-negotiation is incomplete, or if there was an error.
103  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
104  */
105 static inline int phy_aneg_done(struct phy_device *phydev)
106 {
107 	int retval;
108 
109 	retval = phy_read(phydev, MII_BMSR);
110 
111 	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
112 }
113 
114 /* A structure for mapping a particular speed and duplex
115  * combination to a particular SUPPORTED and ADVERTISED value */
116 struct phy_setting {
117 	int speed;
118 	int duplex;
119 	u32 setting;
120 };
121 
122 /* A mapping of all SUPPORTED settings to speed/duplex */
123 static const struct phy_setting settings[] = {
124 	{
125 		.speed = 10000,
126 		.duplex = DUPLEX_FULL,
127 		.setting = SUPPORTED_10000baseT_Full,
128 	},
129 	{
130 		.speed = SPEED_1000,
131 		.duplex = DUPLEX_FULL,
132 		.setting = SUPPORTED_1000baseT_Full,
133 	},
134 	{
135 		.speed = SPEED_1000,
136 		.duplex = DUPLEX_HALF,
137 		.setting = SUPPORTED_1000baseT_Half,
138 	},
139 	{
140 		.speed = SPEED_100,
141 		.duplex = DUPLEX_FULL,
142 		.setting = SUPPORTED_100baseT_Full,
143 	},
144 	{
145 		.speed = SPEED_100,
146 		.duplex = DUPLEX_HALF,
147 		.setting = SUPPORTED_100baseT_Half,
148 	},
149 	{
150 		.speed = SPEED_10,
151 		.duplex = DUPLEX_FULL,
152 		.setting = SUPPORTED_10baseT_Full,
153 	},
154 	{
155 		.speed = SPEED_10,
156 		.duplex = DUPLEX_HALF,
157 		.setting = SUPPORTED_10baseT_Half,
158 	},
159 };
160 
161 #define MAX_NUM_SETTINGS ARRAY_SIZE(settings)
162 
163 /**
164  * phy_find_setting - find a PHY settings array entry that matches speed & duplex
165  * @speed: speed to match
166  * @duplex: duplex to match
167  *
168  * Description: Searches the settings array for the setting which
169  *   matches the desired speed and duplex, and returns the index
170  *   of that setting.  Returns the index of the last setting if
171  *   none of the others match.
172  */
173 static inline int phy_find_setting(int speed, int duplex)
174 {
175 	int idx = 0;
176 
177 	while (idx < ARRAY_SIZE(settings) &&
178 			(settings[idx].speed != speed ||
179 			settings[idx].duplex != duplex))
180 		idx++;
181 
182 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
183 }
184 
185 /**
186  * phy_find_valid - find a PHY setting that matches the requested features mask
187  * @idx: The first index in settings[] to search
188  * @features: A mask of the valid settings
189  *
190  * Description: Returns the index of the first valid setting less
191  *   than or equal to the one pointed to by idx, as determined by
192  *   the mask in features.  Returns the index of the last setting
193  *   if nothing else matches.
194  */
195 static inline int phy_find_valid(int idx, u32 features)
196 {
197 	while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
198 		idx++;
199 
200 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
201 }
202 
203 /**
204  * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
205  * @phydev: the target phy_device struct
206  *
207  * Description: Make sure the PHY is set to supported speeds and
208  *   duplexes.  Drop down by one in this order:  1000/FULL,
209  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
210  */
211 static void phy_sanitize_settings(struct phy_device *phydev)
212 {
213 	u32 features = phydev->supported;
214 	int idx;
215 
216 	/* Sanitize settings based on PHY capabilities */
217 	if ((features & SUPPORTED_Autoneg) == 0)
218 		phydev->autoneg = AUTONEG_DISABLE;
219 
220 	idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
221 			features);
222 
223 	phydev->speed = settings[idx].speed;
224 	phydev->duplex = settings[idx].duplex;
225 }
226 
227 /**
228  * phy_ethtool_sset - generic ethtool sset function, handles all the details
229  * @phydev: target phy_device struct
230  * @cmd: ethtool_cmd
231  *
232  * A few notes about parameter checking:
233  * - We don't set port or transceiver, so we don't care what they
234  *   were set to.
235  * - phy_start_aneg() will make sure forced settings are sane, and
236  *   choose the next best ones from the ones selected, so we don't
237  *   care if ethtool tries to give us bad values.
238  */
239 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
240 {
241 	if (cmd->phy_address != phydev->addr)
242 		return -EINVAL;
243 
244 	/* We make sure that we don't pass unsupported
245 	 * values in to the PHY */
246 	cmd->advertising &= phydev->supported;
247 
248 	/* Verify the settings we care about. */
249 	if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
250 		return -EINVAL;
251 
252 	if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
253 		return -EINVAL;
254 
255 	if (cmd->autoneg == AUTONEG_DISABLE &&
256 	    ((cmd->speed != SPEED_1000 &&
257 	      cmd->speed != SPEED_100 &&
258 	      cmd->speed != SPEED_10) ||
259 	     (cmd->duplex != DUPLEX_HALF &&
260 	      cmd->duplex != DUPLEX_FULL)))
261 		return -EINVAL;
262 
263 	phydev->autoneg = cmd->autoneg;
264 
265 	phydev->speed = cmd->speed;
266 
267 	phydev->advertising = cmd->advertising;
268 
269 	if (AUTONEG_ENABLE == cmd->autoneg)
270 		phydev->advertising |= ADVERTISED_Autoneg;
271 	else
272 		phydev->advertising &= ~ADVERTISED_Autoneg;
273 
274 	phydev->duplex = cmd->duplex;
275 
276 	/* Restart the PHY */
277 	phy_start_aneg(phydev);
278 
279 	return 0;
280 }
281 EXPORT_SYMBOL(phy_ethtool_sset);
282 
283 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
284 {
285 	cmd->supported = phydev->supported;
286 
287 	cmd->advertising = phydev->advertising;
288 
289 	cmd->speed = phydev->speed;
290 	cmd->duplex = phydev->duplex;
291 	cmd->port = PORT_MII;
292 	cmd->phy_address = phydev->addr;
293 	cmd->transceiver = XCVR_EXTERNAL;
294 	cmd->autoneg = phydev->autoneg;
295 
296 	return 0;
297 }
298 EXPORT_SYMBOL(phy_ethtool_gset);
299 
300 /**
301  * phy_mii_ioctl - generic PHY MII ioctl interface
302  * @phydev: the phy_device struct
303  * @ifr: &struct ifreq for socket ioctl's
304  * @cmd: ioctl cmd to execute
305  *
306  * Note that this function is currently incompatible with the
307  * PHYCONTROL layer.  It changes registers without regard to
308  * current state.  Use at own risk.
309  */
310 int phy_mii_ioctl(struct phy_device *phydev,
311 		struct ifreq *ifr, int cmd)
312 {
313 	struct mii_ioctl_data *mii_data = if_mii(ifr);
314 	u16 val = mii_data->val_in;
315 
316 	switch (cmd) {
317 	case SIOCGMIIPHY:
318 		mii_data->phy_id = phydev->addr;
319 		/* fall through */
320 
321 	case SIOCGMIIREG:
322 		mii_data->val_out = phy_read(phydev, mii_data->reg_num);
323 		break;
324 
325 	case SIOCSMIIREG:
326 		if (mii_data->phy_id == phydev->addr) {
327 			switch(mii_data->reg_num) {
328 			case MII_BMCR:
329 				if ((val & (BMCR_RESET|BMCR_ANENABLE)) == 0)
330 					phydev->autoneg = AUTONEG_DISABLE;
331 				else
332 					phydev->autoneg = AUTONEG_ENABLE;
333 				if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
334 					phydev->duplex = DUPLEX_FULL;
335 				else
336 					phydev->duplex = DUPLEX_HALF;
337 				if ((!phydev->autoneg) &&
338 						(val & BMCR_SPEED1000))
339 					phydev->speed = SPEED_1000;
340 				else if ((!phydev->autoneg) &&
341 						(val & BMCR_SPEED100))
342 					phydev->speed = SPEED_100;
343 				break;
344 			case MII_ADVERTISE:
345 				phydev->advertising = val;
346 				break;
347 			default:
348 				/* do nothing */
349 				break;
350 			}
351 		}
352 
353 		phy_write(phydev, mii_data->reg_num, val);
354 
355 		if (mii_data->reg_num == MII_BMCR &&
356 		    val & BMCR_RESET &&
357 		    phydev->drv->config_init) {
358 			phy_scan_fixups(phydev);
359 			phydev->drv->config_init(phydev);
360 		}
361 		break;
362 
363 	case SIOCSHWTSTAMP:
364 		if (phydev->drv->hwtstamp)
365 			return phydev->drv->hwtstamp(phydev, ifr);
366 		/* fall through */
367 
368 	default:
369 		return -EOPNOTSUPP;
370 	}
371 
372 	return 0;
373 }
374 EXPORT_SYMBOL(phy_mii_ioctl);
375 
376 /**
377  * phy_start_aneg - start auto-negotiation for this PHY device
378  * @phydev: the phy_device struct
379  *
380  * Description: Sanitizes the settings (if we're not autonegotiating
381  *   them), and then calls the driver's config_aneg function.
382  *   If the PHYCONTROL Layer is operating, we change the state to
383  *   reflect the beginning of Auto-negotiation or forcing.
384  */
385 int phy_start_aneg(struct phy_device *phydev)
386 {
387 	int err;
388 
389 	mutex_lock(&phydev->lock);
390 
391 	if (AUTONEG_DISABLE == phydev->autoneg)
392 		phy_sanitize_settings(phydev);
393 
394 	err = phydev->drv->config_aneg(phydev);
395 
396 	if (err < 0)
397 		goto out_unlock;
398 
399 	if (phydev->state != PHY_HALTED) {
400 		if (AUTONEG_ENABLE == phydev->autoneg) {
401 			phydev->state = PHY_AN;
402 			phydev->link_timeout = PHY_AN_TIMEOUT;
403 		} else {
404 			phydev->state = PHY_FORCING;
405 			phydev->link_timeout = PHY_FORCE_TIMEOUT;
406 		}
407 	}
408 
409 out_unlock:
410 	mutex_unlock(&phydev->lock);
411 	return err;
412 }
413 EXPORT_SYMBOL(phy_start_aneg);
414 
415 
416 static void phy_change(struct work_struct *work);
417 
418 /**
419  * phy_start_machine - start PHY state machine tracking
420  * @phydev: the phy_device struct
421  * @handler: callback function for state change notifications
422  *
423  * Description: The PHY infrastructure can run a state machine
424  *   which tracks whether the PHY is starting up, negotiating,
425  *   etc.  This function starts the timer which tracks the state
426  *   of the PHY.  If you want to be notified when the state changes,
427  *   pass in the callback @handler, otherwise, pass NULL.  If you
428  *   want to maintain your own state machine, do not call this
429  *   function.
430  */
431 void phy_start_machine(struct phy_device *phydev,
432 		void (*handler)(struct net_device *))
433 {
434 	phydev->adjust_state = handler;
435 
436 	schedule_delayed_work(&phydev->state_queue, HZ);
437 }
438 
439 /**
440  * phy_stop_machine - stop the PHY state machine tracking
441  * @phydev: target phy_device struct
442  *
443  * Description: Stops the state machine timer, sets the state to UP
444  *   (unless it wasn't up yet). This function must be called BEFORE
445  *   phy_detach.
446  */
447 void phy_stop_machine(struct phy_device *phydev)
448 {
449 	cancel_delayed_work_sync(&phydev->state_queue);
450 
451 	mutex_lock(&phydev->lock);
452 	if (phydev->state > PHY_UP)
453 		phydev->state = PHY_UP;
454 	mutex_unlock(&phydev->lock);
455 
456 	phydev->adjust_state = NULL;
457 }
458 
459 /**
460  * phy_force_reduction - reduce PHY speed/duplex settings by one step
461  * @phydev: target phy_device struct
462  *
463  * Description: Reduces the speed/duplex settings by one notch,
464  *   in this order--
465  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
466  *   The function bottoms out at 10/HALF.
467  */
468 static void phy_force_reduction(struct phy_device *phydev)
469 {
470 	int idx;
471 
472 	idx = phy_find_setting(phydev->speed, phydev->duplex);
473 
474 	idx++;
475 
476 	idx = phy_find_valid(idx, phydev->supported);
477 
478 	phydev->speed = settings[idx].speed;
479 	phydev->duplex = settings[idx].duplex;
480 
481 	pr_info("Trying %d/%s\n", phydev->speed,
482 			DUPLEX_FULL == phydev->duplex ?
483 			"FULL" : "HALF");
484 }
485 
486 
487 /**
488  * phy_error - enter HALTED state for this PHY device
489  * @phydev: target phy_device struct
490  *
491  * Moves the PHY to the HALTED state in response to a read
492  * or write error, and tells the controller the link is down.
493  * Must not be called from interrupt context, or while the
494  * phydev->lock is held.
495  */
496 static void phy_error(struct phy_device *phydev)
497 {
498 	mutex_lock(&phydev->lock);
499 	phydev->state = PHY_HALTED;
500 	mutex_unlock(&phydev->lock);
501 }
502 
503 /**
504  * phy_interrupt - PHY interrupt handler
505  * @irq: interrupt line
506  * @phy_dat: phy_device pointer
507  *
508  * Description: When a PHY interrupt occurs, the handler disables
509  * interrupts, and schedules a work task to clear the interrupt.
510  */
511 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
512 {
513 	struct phy_device *phydev = phy_dat;
514 
515 	if (PHY_HALTED == phydev->state)
516 		return IRQ_NONE;		/* It can't be ours.  */
517 
518 	/* The MDIO bus is not allowed to be written in interrupt
519 	 * context, so we need to disable the irq here.  A work
520 	 * queue will write the PHY to disable and clear the
521 	 * interrupt, and then reenable the irq line. */
522 	disable_irq_nosync(irq);
523 	atomic_inc(&phydev->irq_disable);
524 
525 	schedule_work(&phydev->phy_queue);
526 
527 	return IRQ_HANDLED;
528 }
529 
530 /**
531  * phy_enable_interrupts - Enable the interrupts from the PHY side
532  * @phydev: target phy_device struct
533  */
534 static int phy_enable_interrupts(struct phy_device *phydev)
535 {
536 	int err;
537 
538 	err = phy_clear_interrupt(phydev);
539 
540 	if (err < 0)
541 		return err;
542 
543 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
544 
545 	return err;
546 }
547 
548 /**
549  * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
550  * @phydev: target phy_device struct
551  */
552 static int phy_disable_interrupts(struct phy_device *phydev)
553 {
554 	int err;
555 
556 	/* Disable PHY interrupts */
557 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
558 
559 	if (err)
560 		goto phy_err;
561 
562 	/* Clear the interrupt */
563 	err = phy_clear_interrupt(phydev);
564 
565 	if (err)
566 		goto phy_err;
567 
568 	return 0;
569 
570 phy_err:
571 	phy_error(phydev);
572 
573 	return err;
574 }
575 
576 /**
577  * phy_start_interrupts - request and enable interrupts for a PHY device
578  * @phydev: target phy_device struct
579  *
580  * Description: Request the interrupt for the given PHY.
581  *   If this fails, then we set irq to PHY_POLL.
582  *   Otherwise, we enable the interrupts in the PHY.
583  *   This should only be called with a valid IRQ number.
584  *   Returns 0 on success or < 0 on error.
585  */
586 int phy_start_interrupts(struct phy_device *phydev)
587 {
588 	int err = 0;
589 
590 	INIT_WORK(&phydev->phy_queue, phy_change);
591 
592 	atomic_set(&phydev->irq_disable, 0);
593 	if (request_irq(phydev->irq, phy_interrupt,
594 				IRQF_SHARED,
595 				"phy_interrupt",
596 				phydev) < 0) {
597 		printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
598 				phydev->bus->name,
599 				phydev->irq);
600 		phydev->irq = PHY_POLL;
601 		return 0;
602 	}
603 
604 	err = phy_enable_interrupts(phydev);
605 
606 	return err;
607 }
608 EXPORT_SYMBOL(phy_start_interrupts);
609 
610 /**
611  * phy_stop_interrupts - disable interrupts from a PHY device
612  * @phydev: target phy_device struct
613  */
614 int phy_stop_interrupts(struct phy_device *phydev)
615 {
616 	int err;
617 
618 	err = phy_disable_interrupts(phydev);
619 
620 	if (err)
621 		phy_error(phydev);
622 
623 	free_irq(phydev->irq, phydev);
624 
625 	/*
626 	 * Cannot call flush_scheduled_work() here as desired because
627 	 * of rtnl_lock(), but we do not really care about what would
628 	 * be done, except from enable_irq(), so cancel any work
629 	 * possibly pending and take care of the matter below.
630 	 */
631 	cancel_work_sync(&phydev->phy_queue);
632 	/*
633 	 * If work indeed has been cancelled, disable_irq() will have
634 	 * been left unbalanced from phy_interrupt() and enable_irq()
635 	 * has to be called so that other devices on the line work.
636 	 */
637 	while (atomic_dec_return(&phydev->irq_disable) >= 0)
638 		enable_irq(phydev->irq);
639 
640 	return err;
641 }
642 EXPORT_SYMBOL(phy_stop_interrupts);
643 
644 
645 /**
646  * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
647  * @work: work_struct that describes the work to be done
648  */
649 static void phy_change(struct work_struct *work)
650 {
651 	int err;
652 	struct phy_device *phydev =
653 		container_of(work, struct phy_device, phy_queue);
654 
655 	if (phydev->drv->did_interrupt &&
656 	    !phydev->drv->did_interrupt(phydev))
657 		goto ignore;
658 
659 	err = phy_disable_interrupts(phydev);
660 
661 	if (err)
662 		goto phy_err;
663 
664 	mutex_lock(&phydev->lock);
665 	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
666 		phydev->state = PHY_CHANGELINK;
667 	mutex_unlock(&phydev->lock);
668 
669 	atomic_dec(&phydev->irq_disable);
670 	enable_irq(phydev->irq);
671 
672 	/* Reenable interrupts */
673 	if (PHY_HALTED != phydev->state)
674 		err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
675 
676 	if (err)
677 		goto irq_enable_err;
678 
679 	/* reschedule state queue work to run as soon as possible */
680 	cancel_delayed_work_sync(&phydev->state_queue);
681 	schedule_delayed_work(&phydev->state_queue, 0);
682 
683 	return;
684 
685 ignore:
686 	atomic_dec(&phydev->irq_disable);
687 	enable_irq(phydev->irq);
688 	return;
689 
690 irq_enable_err:
691 	disable_irq(phydev->irq);
692 	atomic_inc(&phydev->irq_disable);
693 phy_err:
694 	phy_error(phydev);
695 }
696 
697 /**
698  * phy_stop - Bring down the PHY link, and stop checking the status
699  * @phydev: target phy_device struct
700  */
701 void phy_stop(struct phy_device *phydev)
702 {
703 	mutex_lock(&phydev->lock);
704 
705 	if (PHY_HALTED == phydev->state)
706 		goto out_unlock;
707 
708 	if (phydev->irq != PHY_POLL) {
709 		/* Disable PHY Interrupts */
710 		phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
711 
712 		/* Clear any pending interrupts */
713 		phy_clear_interrupt(phydev);
714 	}
715 
716 	phydev->state = PHY_HALTED;
717 
718 out_unlock:
719 	mutex_unlock(&phydev->lock);
720 
721 	/*
722 	 * Cannot call flush_scheduled_work() here as desired because
723 	 * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
724 	 * will not reenable interrupts.
725 	 */
726 }
727 
728 
729 /**
730  * phy_start - start or restart a PHY device
731  * @phydev: target phy_device struct
732  *
733  * Description: Indicates the attached device's readiness to
734  *   handle PHY-related work.  Used during startup to start the
735  *   PHY, and after a call to phy_stop() to resume operation.
736  *   Also used to indicate the MDIO bus has cleared an error
737  *   condition.
738  */
739 void phy_start(struct phy_device *phydev)
740 {
741 	mutex_lock(&phydev->lock);
742 
743 	switch (phydev->state) {
744 		case PHY_STARTING:
745 			phydev->state = PHY_PENDING;
746 			break;
747 		case PHY_READY:
748 			phydev->state = PHY_UP;
749 			break;
750 		case PHY_HALTED:
751 			phydev->state = PHY_RESUMING;
752 		default:
753 			break;
754 	}
755 	mutex_unlock(&phydev->lock);
756 }
757 EXPORT_SYMBOL(phy_stop);
758 EXPORT_SYMBOL(phy_start);
759 
760 /**
761  * phy_state_machine - Handle the state machine
762  * @work: work_struct that describes the work to be done
763  */
764 void phy_state_machine(struct work_struct *work)
765 {
766 	struct delayed_work *dwork = to_delayed_work(work);
767 	struct phy_device *phydev =
768 			container_of(dwork, struct phy_device, state_queue);
769 	int needs_aneg = 0;
770 	int err = 0;
771 
772 	mutex_lock(&phydev->lock);
773 
774 	if (phydev->adjust_state)
775 		phydev->adjust_state(phydev->attached_dev);
776 
777 	switch(phydev->state) {
778 		case PHY_DOWN:
779 		case PHY_STARTING:
780 		case PHY_READY:
781 		case PHY_PENDING:
782 			break;
783 		case PHY_UP:
784 			needs_aneg = 1;
785 
786 			phydev->link_timeout = PHY_AN_TIMEOUT;
787 
788 			break;
789 		case PHY_AN:
790 			err = phy_read_status(phydev);
791 
792 			if (err < 0)
793 				break;
794 
795 			/* If the link is down, give up on
796 			 * negotiation for now */
797 			if (!phydev->link) {
798 				phydev->state = PHY_NOLINK;
799 				netif_carrier_off(phydev->attached_dev);
800 				phydev->adjust_link(phydev->attached_dev);
801 				break;
802 			}
803 
804 			/* Check if negotiation is done.  Break
805 			 * if there's an error */
806 			err = phy_aneg_done(phydev);
807 			if (err < 0)
808 				break;
809 
810 			/* If AN is done, we're running */
811 			if (err > 0) {
812 				phydev->state = PHY_RUNNING;
813 				netif_carrier_on(phydev->attached_dev);
814 				phydev->adjust_link(phydev->attached_dev);
815 
816 			} else if (0 == phydev->link_timeout--) {
817 				int idx;
818 
819 				needs_aneg = 1;
820 				/* If we have the magic_aneg bit,
821 				 * we try again */
822 				if (phydev->drv->flags & PHY_HAS_MAGICANEG)
823 					break;
824 
825 				/* The timer expired, and we still
826 				 * don't have a setting, so we try
827 				 * forcing it until we find one that
828 				 * works, starting from the fastest speed,
829 				 * and working our way down */
830 				idx = phy_find_valid(0, phydev->supported);
831 
832 				phydev->speed = settings[idx].speed;
833 				phydev->duplex = settings[idx].duplex;
834 
835 				phydev->autoneg = AUTONEG_DISABLE;
836 
837 				pr_info("Trying %d/%s\n", phydev->speed,
838 						DUPLEX_FULL ==
839 						phydev->duplex ?
840 						"FULL" : "HALF");
841 			}
842 			break;
843 		case PHY_NOLINK:
844 			err = phy_read_status(phydev);
845 
846 			if (err)
847 				break;
848 
849 			if (phydev->link) {
850 				phydev->state = PHY_RUNNING;
851 				netif_carrier_on(phydev->attached_dev);
852 				phydev->adjust_link(phydev->attached_dev);
853 			}
854 			break;
855 		case PHY_FORCING:
856 			err = genphy_update_link(phydev);
857 
858 			if (err)
859 				break;
860 
861 			if (phydev->link) {
862 				phydev->state = PHY_RUNNING;
863 				netif_carrier_on(phydev->attached_dev);
864 			} else {
865 				if (0 == phydev->link_timeout--) {
866 					phy_force_reduction(phydev);
867 					needs_aneg = 1;
868 				}
869 			}
870 
871 			phydev->adjust_link(phydev->attached_dev);
872 			break;
873 		case PHY_RUNNING:
874 			/* Only register a CHANGE if we are
875 			 * polling */
876 			if (PHY_POLL == phydev->irq)
877 				phydev->state = PHY_CHANGELINK;
878 			break;
879 		case PHY_CHANGELINK:
880 			err = phy_read_status(phydev);
881 
882 			if (err)
883 				break;
884 
885 			if (phydev->link) {
886 				phydev->state = PHY_RUNNING;
887 				netif_carrier_on(phydev->attached_dev);
888 			} else {
889 				phydev->state = PHY_NOLINK;
890 				netif_carrier_off(phydev->attached_dev);
891 			}
892 
893 			phydev->adjust_link(phydev->attached_dev);
894 
895 			if (PHY_POLL != phydev->irq)
896 				err = phy_config_interrupt(phydev,
897 						PHY_INTERRUPT_ENABLED);
898 			break;
899 		case PHY_HALTED:
900 			if (phydev->link) {
901 				phydev->link = 0;
902 				netif_carrier_off(phydev->attached_dev);
903 				phydev->adjust_link(phydev->attached_dev);
904 			}
905 			break;
906 		case PHY_RESUMING:
907 
908 			err = phy_clear_interrupt(phydev);
909 
910 			if (err)
911 				break;
912 
913 			err = phy_config_interrupt(phydev,
914 					PHY_INTERRUPT_ENABLED);
915 
916 			if (err)
917 				break;
918 
919 			if (AUTONEG_ENABLE == phydev->autoneg) {
920 				err = phy_aneg_done(phydev);
921 				if (err < 0)
922 					break;
923 
924 				/* err > 0 if AN is done.
925 				 * Otherwise, it's 0, and we're
926 				 * still waiting for AN */
927 				if (err > 0) {
928 					err = phy_read_status(phydev);
929 					if (err)
930 						break;
931 
932 					if (phydev->link) {
933 						phydev->state = PHY_RUNNING;
934 						netif_carrier_on(phydev->attached_dev);
935 					} else
936 						phydev->state = PHY_NOLINK;
937 					phydev->adjust_link(phydev->attached_dev);
938 				} else {
939 					phydev->state = PHY_AN;
940 					phydev->link_timeout = PHY_AN_TIMEOUT;
941 				}
942 			} else {
943 				err = phy_read_status(phydev);
944 				if (err)
945 					break;
946 
947 				if (phydev->link) {
948 					phydev->state = PHY_RUNNING;
949 					netif_carrier_on(phydev->attached_dev);
950 				} else
951 					phydev->state = PHY_NOLINK;
952 				phydev->adjust_link(phydev->attached_dev);
953 			}
954 			break;
955 	}
956 
957 	mutex_unlock(&phydev->lock);
958 
959 	if (needs_aneg)
960 		err = phy_start_aneg(phydev);
961 
962 	if (err < 0)
963 		phy_error(phydev);
964 
965 	schedule_delayed_work(&phydev->state_queue, PHY_STATE_TIME * HZ);
966 }
967