drivers/net/: all drivers/net/ cleanup with ARRAY_SIZE
[linux-2.6.git] / drivers / net / phy / phy.c
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  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/spinlock.h>
30 #include <linux/mm.h>
31 #include <linux/module.h>
32 #include <linux/mii.h>
33 #include <linux/ethtool.h>
34 #include <linux/phy.h>
35 #include <linux/timer.h>
36 #include <linux/workqueue.h>
37
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", phydev->dev.bus_id,
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_read - Convenience function for reading a given PHY register
62  * @phydev: the phy_device struct
63  * @regnum: register number to read
64  *
65  * NOTE: MUST NOT be called from interrupt context,
66  * because the bus read/write functions may wait for an interrupt
67  * to conclude the operation.
68  */
69 int phy_read(struct phy_device *phydev, u16 regnum)
70 {
71         int retval;
72         struct mii_bus *bus = phydev->bus;
73
74         spin_lock_bh(&bus->mdio_lock);
75         retval = bus->read(bus, phydev->addr, regnum);
76         spin_unlock_bh(&bus->mdio_lock);
77
78         return retval;
79 }
80 EXPORT_SYMBOL(phy_read);
81
82 /**
83  * phy_write - Convenience function for writing a given PHY register
84  * @phydev: the phy_device struct
85  * @regnum: register number to write
86  * @val: value to write to @regnum
87  *
88  * NOTE: MUST NOT be called from interrupt context,
89  * because the bus read/write functions may wait for an interrupt
90  * to conclude the operation.
91  */
92 int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
93 {
94         int err;
95         struct mii_bus *bus = phydev->bus;
96
97         spin_lock_bh(&bus->mdio_lock);
98         err = bus->write(bus, phydev->addr, regnum, val);
99         spin_unlock_bh(&bus->mdio_lock);
100
101         return err;
102 }
103 EXPORT_SYMBOL(phy_write);
104
105 /**
106  * phy_clear_interrupt - Ack the phy device's interrupt
107  * @phydev: the phy_device struct
108  *
109  * If the @phydev driver has an ack_interrupt function, call it to
110  * ack and clear the phy device's interrupt.
111  *
112  * Returns 0 on success on < 0 on error.
113  */
114 int phy_clear_interrupt(struct phy_device *phydev)
115 {
116         int err = 0;
117
118         if (phydev->drv->ack_interrupt)
119                 err = phydev->drv->ack_interrupt(phydev);
120
121         return err;
122 }
123
124 /**
125  * phy_config_interrupt - configure the PHY device for the requested interrupts
126  * @phydev: the phy_device struct
127  * @interrupts: interrupt flags to configure for this @phydev
128  *
129  * Returns 0 on success on < 0 on error.
130  */
131 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
132 {
133         int err = 0;
134
135         phydev->interrupts = interrupts;
136         if (phydev->drv->config_intr)
137                 err = phydev->drv->config_intr(phydev);
138
139         return err;
140 }
141
142
143 /**
144  * phy_aneg_done - return auto-negotiation status
145  * @phydev: target phy_device struct
146  *
147  * Description: Reads the status register and returns 0 either if
148  *   auto-negotiation is incomplete, or if there was an error.
149  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
150  */
151 static inline int phy_aneg_done(struct phy_device *phydev)
152 {
153         int retval;
154
155         retval = phy_read(phydev, MII_BMSR);
156
157         return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
158 }
159
160 /* A structure for mapping a particular speed and duplex
161  * combination to a particular SUPPORTED and ADVERTISED value */
162 struct phy_setting {
163         int speed;
164         int duplex;
165         u32 setting;
166 };
167
168 /* A mapping of all SUPPORTED settings to speed/duplex */
169 static const struct phy_setting settings[] = {
170         {
171                 .speed = 10000,
172                 .duplex = DUPLEX_FULL,
173                 .setting = SUPPORTED_10000baseT_Full,
174         },
175         {
176                 .speed = SPEED_1000,
177                 .duplex = DUPLEX_FULL,
178                 .setting = SUPPORTED_1000baseT_Full,
179         },
180         {
181                 .speed = SPEED_1000,
182                 .duplex = DUPLEX_HALF,
183                 .setting = SUPPORTED_1000baseT_Half,
184         },
185         {
186                 .speed = SPEED_100,
187                 .duplex = DUPLEX_FULL,
188                 .setting = SUPPORTED_100baseT_Full,
189         },
190         {
191                 .speed = SPEED_100,
192                 .duplex = DUPLEX_HALF,
193                 .setting = SUPPORTED_100baseT_Half,
194         },
195         {
196                 .speed = SPEED_10,
197                 .duplex = DUPLEX_FULL,
198                 .setting = SUPPORTED_10baseT_Full,
199         },
200         {
201                 .speed = SPEED_10,
202                 .duplex = DUPLEX_HALF,
203                 .setting = SUPPORTED_10baseT_Half,
204         },
205 };
206
207 #define MAX_NUM_SETTINGS ARRAY_SIZE(settings)
208
209 /**
210  * phy_find_setting - find a PHY settings array entry that matches speed & duplex
211  * @speed: speed to match
212  * @duplex: duplex to match
213  *
214  * Description: Searches the settings array for the setting which
215  *   matches the desired speed and duplex, and returns the index
216  *   of that setting.  Returns the index of the last setting if
217  *   none of the others match.
218  */
219 static inline int phy_find_setting(int speed, int duplex)
220 {
221         int idx = 0;
222
223         while (idx < ARRAY_SIZE(settings) &&
224                         (settings[idx].speed != speed ||
225                         settings[idx].duplex != duplex))
226                 idx++;
227
228         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
229 }
230
231 /**
232  * phy_find_valid - find a PHY setting that matches the requested features mask
233  * @idx: The first index in settings[] to search
234  * @features: A mask of the valid settings
235  *
236  * Description: Returns the index of the first valid setting less
237  *   than or equal to the one pointed to by idx, as determined by
238  *   the mask in features.  Returns the index of the last setting
239  *   if nothing else matches.
240  */
241 static inline int phy_find_valid(int idx, u32 features)
242 {
243         while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
244                 idx++;
245
246         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
247 }
248
249 /**
250  * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
251  * @phydev: the target phy_device struct
252  *
253  * Description: Make sure the PHY is set to supported speeds and
254  *   duplexes.  Drop down by one in this order:  1000/FULL,
255  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
256  */
257 void phy_sanitize_settings(struct phy_device *phydev)
258 {
259         u32 features = phydev->supported;
260         int idx;
261
262         /* Sanitize settings based on PHY capabilities */
263         if ((features & SUPPORTED_Autoneg) == 0)
264                 phydev->autoneg = AUTONEG_DISABLE;
265
266         idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
267                         features);
268
269         phydev->speed = settings[idx].speed;
270         phydev->duplex = settings[idx].duplex;
271 }
272 EXPORT_SYMBOL(phy_sanitize_settings);
273
274 /**
275  * phy_ethtool_sset - generic ethtool sset function, handles all the details
276  * @phydev: target phy_device struct
277  * @cmd: ethtool_cmd
278  *
279  * A few notes about parameter checking:
280  * - We don't set port or transceiver, so we don't care what they
281  *   were set to.
282  * - phy_start_aneg() will make sure forced settings are sane, and
283  *   choose the next best ones from the ones selected, so we don't
284  *   care if ethtool tries to give us bad values.
285  */
286 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
287 {
288         if (cmd->phy_address != phydev->addr)
289                 return -EINVAL;
290
291         /* We make sure that we don't pass unsupported
292          * values in to the PHY */
293         cmd->advertising &= phydev->supported;
294
295         /* Verify the settings we care about. */
296         if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
297                 return -EINVAL;
298
299         if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
300                 return -EINVAL;
301
302         if (cmd->autoneg == AUTONEG_DISABLE
303                         && ((cmd->speed != SPEED_1000
304                                         && cmd->speed != SPEED_100
305                                         && cmd->speed != SPEED_10)
306                                 || (cmd->duplex != DUPLEX_HALF
307                                         && cmd->duplex != DUPLEX_FULL)))
308                 return -EINVAL;
309
310         phydev->autoneg = cmd->autoneg;
311
312         phydev->speed = cmd->speed;
313
314         phydev->advertising = cmd->advertising;
315
316         if (AUTONEG_ENABLE == cmd->autoneg)
317                 phydev->advertising |= ADVERTISED_Autoneg;
318         else
319                 phydev->advertising &= ~ADVERTISED_Autoneg;
320
321         phydev->duplex = cmd->duplex;
322
323         /* Restart the PHY */
324         phy_start_aneg(phydev);
325
326         return 0;
327 }
328 EXPORT_SYMBOL(phy_ethtool_sset);
329
330 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
331 {
332         cmd->supported = phydev->supported;
333
334         cmd->advertising = phydev->advertising;
335
336         cmd->speed = phydev->speed;
337         cmd->duplex = phydev->duplex;
338         cmd->port = PORT_MII;
339         cmd->phy_address = phydev->addr;
340         cmd->transceiver = XCVR_EXTERNAL;
341         cmd->autoneg = phydev->autoneg;
342
343         return 0;
344 }
345 EXPORT_SYMBOL(phy_ethtool_gset);
346
347 /**
348  * phy_mii_ioctl - generic PHY MII ioctl interface
349  * @phydev: the phy_device struct
350  * @mii_data: MII ioctl data
351  * @cmd: ioctl cmd to execute
352  *
353  * Note that this function is currently incompatible with the
354  * PHYCONTROL layer.  It changes registers without regard to
355  * current state.  Use at own risk.
356  */
357 int phy_mii_ioctl(struct phy_device *phydev,
358                 struct mii_ioctl_data *mii_data, int cmd)
359 {
360         u16 val = mii_data->val_in;
361
362         switch (cmd) {
363         case SIOCGMIIPHY:
364                 mii_data->phy_id = phydev->addr;
365                 break;
366         case SIOCGMIIREG:
367                 mii_data->val_out = phy_read(phydev, mii_data->reg_num);
368                 break;
369
370         case SIOCSMIIREG:
371                 if (!capable(CAP_NET_ADMIN))
372                         return -EPERM;
373
374                 if (mii_data->phy_id == phydev->addr) {
375                         switch(mii_data->reg_num) {
376                         case MII_BMCR:
377                                 if ((val & (BMCR_RESET|BMCR_ANENABLE)) == 0)
378                                         phydev->autoneg = AUTONEG_DISABLE;
379                                 else
380                                         phydev->autoneg = AUTONEG_ENABLE;
381                                 if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
382                                         phydev->duplex = DUPLEX_FULL;
383                                 else
384                                         phydev->duplex = DUPLEX_HALF;
385                                 if ((!phydev->autoneg) &&
386                                                 (val & BMCR_SPEED1000))
387                                         phydev->speed = SPEED_1000;
388                                 else if ((!phydev->autoneg) &&
389                                                 (val & BMCR_SPEED100))
390                                         phydev->speed = SPEED_100;
391                                 break;
392                         case MII_ADVERTISE:
393                                 phydev->advertising = val;
394                                 break;
395                         default:
396                                 /* do nothing */
397                                 break;
398                         }
399                 }
400
401                 phy_write(phydev, mii_data->reg_num, val);
402                 
403                 if (mii_data->reg_num == MII_BMCR 
404                                 && val & BMCR_RESET
405                                 && phydev->drv->config_init)
406                         phydev->drv->config_init(phydev);
407                 break;
408         }
409
410         return 0;
411 }
412 EXPORT_SYMBOL(phy_mii_ioctl);
413
414 /**
415  * phy_start_aneg - start auto-negotiation for this PHY device
416  * @phydev: the phy_device struct
417  *
418  * Description: Sanitizes the settings (if we're not autonegotiating
419  *   them), and then calls the driver's config_aneg function.
420  *   If the PHYCONTROL Layer is operating, we change the state to
421  *   reflect the beginning of Auto-negotiation or forcing.
422  */
423 int phy_start_aneg(struct phy_device *phydev)
424 {
425         int err;
426
427         spin_lock(&phydev->lock);
428
429         if (AUTONEG_DISABLE == phydev->autoneg)
430                 phy_sanitize_settings(phydev);
431
432         err = phydev->drv->config_aneg(phydev);
433
434         if (err < 0)
435                 goto out_unlock;
436
437         if (phydev->state != PHY_HALTED) {
438                 if (AUTONEG_ENABLE == phydev->autoneg) {
439                         phydev->state = PHY_AN;
440                         phydev->link_timeout = PHY_AN_TIMEOUT;
441                 } else {
442                         phydev->state = PHY_FORCING;
443                         phydev->link_timeout = PHY_FORCE_TIMEOUT;
444                 }
445         }
446
447 out_unlock:
448         spin_unlock(&phydev->lock);
449         return err;
450 }
451 EXPORT_SYMBOL(phy_start_aneg);
452
453
454 static void phy_change(struct work_struct *work);
455 static void phy_timer(unsigned long data);
456
457 /**
458  * phy_start_machine - start PHY state machine tracking
459  * @phydev: the phy_device struct
460  * @handler: callback function for state change notifications
461  *
462  * Description: The PHY infrastructure can run a state machine
463  *   which tracks whether the PHY is starting up, negotiating,
464  *   etc.  This function starts the timer which tracks the state
465  *   of the PHY.  If you want to be notified when the state changes,
466  *   pass in the callback @handler, otherwise, pass NULL.  If you
467  *   want to maintain your own state machine, do not call this
468  *   function.
469  */
470 void phy_start_machine(struct phy_device *phydev,
471                 void (*handler)(struct net_device *))
472 {
473         phydev->adjust_state = handler;
474
475         init_timer(&phydev->phy_timer);
476         phydev->phy_timer.function = &phy_timer;
477         phydev->phy_timer.data = (unsigned long) phydev;
478         mod_timer(&phydev->phy_timer, jiffies + HZ);
479 }
480
481 /**
482  * phy_stop_machine - stop the PHY state machine tracking
483  * @phydev: target phy_device struct
484  *
485  * Description: Stops the state machine timer, sets the state to UP
486  *   (unless it wasn't up yet). This function must be called BEFORE
487  *   phy_detach.
488  */
489 void phy_stop_machine(struct phy_device *phydev)
490 {
491         del_timer_sync(&phydev->phy_timer);
492
493         spin_lock(&phydev->lock);
494         if (phydev->state > PHY_UP)
495                 phydev->state = PHY_UP;
496         spin_unlock(&phydev->lock);
497
498         phydev->adjust_state = NULL;
499 }
500
501 /**
502  * phy_force_reduction - reduce PHY speed/duplex settings by one step
503  * @phydev: target phy_device struct
504  *
505  * Description: Reduces the speed/duplex settings by one notch,
506  *   in this order--
507  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
508  *   The function bottoms out at 10/HALF.
509  */
510 static void phy_force_reduction(struct phy_device *phydev)
511 {
512         int idx;
513
514         idx = phy_find_setting(phydev->speed, phydev->duplex);
515         
516         idx++;
517
518         idx = phy_find_valid(idx, phydev->supported);
519
520         phydev->speed = settings[idx].speed;
521         phydev->duplex = settings[idx].duplex;
522
523         pr_info("Trying %d/%s\n", phydev->speed,
524                         DUPLEX_FULL == phydev->duplex ?
525                         "FULL" : "HALF");
526 }
527
528
529 /**
530  * phy_error - enter HALTED state for this PHY device
531  * @phydev: target phy_device struct
532  *
533  * Moves the PHY to the HALTED state in response to a read
534  * or write error, and tells the controller the link is down.
535  * Must not be called from interrupt context, or while the
536  * phydev->lock is held.
537  */
538 void phy_error(struct phy_device *phydev)
539 {
540         spin_lock(&phydev->lock);
541         phydev->state = PHY_HALTED;
542         spin_unlock(&phydev->lock);
543 }
544
545 /**
546  * phy_interrupt - PHY interrupt handler
547  * @irq: interrupt line
548  * @phy_dat: phy_device pointer
549  *
550  * Description: When a PHY interrupt occurs, the handler disables
551  * interrupts, and schedules a work task to clear the interrupt.
552  */
553 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
554 {
555         struct phy_device *phydev = phy_dat;
556
557         if (PHY_HALTED == phydev->state)
558                 return IRQ_NONE;                /* It can't be ours.  */
559
560         /* The MDIO bus is not allowed to be written in interrupt
561          * context, so we need to disable the irq here.  A work
562          * queue will write the PHY to disable and clear the
563          * interrupt, and then reenable the irq line. */
564         disable_irq_nosync(irq);
565
566         schedule_work(&phydev->phy_queue);
567
568         return IRQ_HANDLED;
569 }
570
571 /**
572  * phy_enable_interrupts - Enable the interrupts from the PHY side
573  * @phydev: target phy_device struct
574  */
575 int phy_enable_interrupts(struct phy_device *phydev)
576 {
577         int err;
578
579         err = phy_clear_interrupt(phydev);
580
581         if (err < 0)
582                 return err;
583
584         err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
585
586         return err;
587 }
588 EXPORT_SYMBOL(phy_enable_interrupts);
589
590 /**
591  * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
592  * @phydev: target phy_device struct
593  */
594 int phy_disable_interrupts(struct phy_device *phydev)
595 {
596         int err;
597
598         /* Disable PHY interrupts */
599         err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
600
601         if (err)
602                 goto phy_err;
603
604         /* Clear the interrupt */
605         err = phy_clear_interrupt(phydev);
606
607         if (err)
608                 goto phy_err;
609
610         return 0;
611
612 phy_err:
613         phy_error(phydev);
614
615         return err;
616 }
617 EXPORT_SYMBOL(phy_disable_interrupts);
618
619 /**
620  * phy_start_interrupts - request and enable interrupts for a PHY device
621  * @phydev: target phy_device struct
622  *
623  * Description: Request the interrupt for the given PHY.
624  *   If this fails, then we set irq to PHY_POLL.
625  *   Otherwise, we enable the interrupts in the PHY.
626  *   This should only be called with a valid IRQ number.
627  *   Returns 0 on success or < 0 on error.
628  */
629 int phy_start_interrupts(struct phy_device *phydev)
630 {
631         int err = 0;
632
633         INIT_WORK(&phydev->phy_queue, phy_change);
634
635         if (request_irq(phydev->irq, phy_interrupt,
636                                 IRQF_SHARED,
637                                 "phy_interrupt",
638                                 phydev) < 0) {
639                 printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
640                                 phydev->bus->name,
641                                 phydev->irq);
642                 phydev->irq = PHY_POLL;
643                 return 0;
644         }
645
646         err = phy_enable_interrupts(phydev);
647
648         return err;
649 }
650 EXPORT_SYMBOL(phy_start_interrupts);
651
652 /**
653  * phy_stop_interrupts - disable interrupts from a PHY device
654  * @phydev: target phy_device struct
655  */
656 int phy_stop_interrupts(struct phy_device *phydev)
657 {
658         int err;
659
660         err = phy_disable_interrupts(phydev);
661
662         if (err)
663                 phy_error(phydev);
664
665         /*
666          * Finish any pending work; we might have been scheduled to be called
667          * from keventd ourselves, but cancel_work_sync() handles that.
668          */
669         cancel_work_sync(&phydev->phy_queue);
670
671         free_irq(phydev->irq, phydev);
672
673         return err;
674 }
675 EXPORT_SYMBOL(phy_stop_interrupts);
676
677
678 /**
679  * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
680  * @work: work_struct that describes the work to be done
681  */
682 static void phy_change(struct work_struct *work)
683 {
684         int err;
685         struct phy_device *phydev =
686                 container_of(work, struct phy_device, phy_queue);
687
688         err = phy_disable_interrupts(phydev);
689
690         if (err)
691                 goto phy_err;
692
693         spin_lock(&phydev->lock);
694         if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
695                 phydev->state = PHY_CHANGELINK;
696         spin_unlock(&phydev->lock);
697
698         enable_irq(phydev->irq);
699
700         /* Reenable interrupts */
701         if (PHY_HALTED != phydev->state)
702                 err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
703
704         if (err)
705                 goto irq_enable_err;
706
707         return;
708
709 irq_enable_err:
710         disable_irq(phydev->irq);
711 phy_err:
712         phy_error(phydev);
713 }
714
715 /**
716  * phy_stop - Bring down the PHY link, and stop checking the status
717  * @phydev: target phy_device struct
718  */
719 void phy_stop(struct phy_device *phydev)
720 {
721         spin_lock(&phydev->lock);
722
723         if (PHY_HALTED == phydev->state)
724                 goto out_unlock;
725
726         phydev->state = PHY_HALTED;
727
728         if (phydev->irq != PHY_POLL) {
729                 /* Disable PHY Interrupts */
730                 phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
731
732                 /* Clear any pending interrupts */
733                 phy_clear_interrupt(phydev);
734         }
735
736 out_unlock:
737         spin_unlock(&phydev->lock);
738
739         /*
740          * Cannot call flush_scheduled_work() here as desired because
741          * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
742          * will not reenable interrupts.
743          */
744 }
745
746
747 /**
748  * phy_start - start or restart a PHY device
749  * @phydev: target phy_device struct
750  *
751  * Description: Indicates the attached device's readiness to
752  *   handle PHY-related work.  Used during startup to start the
753  *   PHY, and after a call to phy_stop() to resume operation.
754  *   Also used to indicate the MDIO bus has cleared an error
755  *   condition.
756  */
757 void phy_start(struct phy_device *phydev)
758 {
759         spin_lock_bh(&phydev->lock);
760
761         switch (phydev->state) {
762                 case PHY_STARTING:
763                         phydev->state = PHY_PENDING;
764                         break;
765                 case PHY_READY:
766                         phydev->state = PHY_UP;
767                         break;
768                 case PHY_HALTED:
769                         phydev->state = PHY_RESUMING;
770                 default:
771                         break;
772         }
773         spin_unlock_bh(&phydev->lock);
774 }
775 EXPORT_SYMBOL(phy_stop);
776 EXPORT_SYMBOL(phy_start);
777
778 /* PHY timer which handles the state machine */
779 static void phy_timer(unsigned long data)
780 {
781         struct phy_device *phydev = (struct phy_device *)data;
782         int needs_aneg = 0;
783         int err = 0;
784
785         spin_lock(&phydev->lock);
786
787         if (phydev->adjust_state)
788                 phydev->adjust_state(phydev->attached_dev);
789
790         switch(phydev->state) {
791                 case PHY_DOWN:
792                 case PHY_STARTING:
793                 case PHY_READY:
794                 case PHY_PENDING:
795                         break;
796                 case PHY_UP:
797                         needs_aneg = 1;
798
799                         phydev->link_timeout = PHY_AN_TIMEOUT;
800
801                         break;
802                 case PHY_AN:
803                         err = phy_read_status(phydev);
804
805                         if (err < 0)
806                                 break;
807
808                         /* If the link is down, give up on
809                          * negotiation for now */
810                         if (!phydev->link) {
811                                 phydev->state = PHY_NOLINK;
812                                 netif_carrier_off(phydev->attached_dev);
813                                 phydev->adjust_link(phydev->attached_dev);
814                                 break;
815                         }
816
817                         /* Check if negotiation is done.  Break
818                          * if there's an error */
819                         err = phy_aneg_done(phydev);
820                         if (err < 0)
821                                 break;
822
823                         /* If AN is done, we're running */
824                         if (err > 0) {
825                                 phydev->state = PHY_RUNNING;
826                                 netif_carrier_on(phydev->attached_dev);
827                                 phydev->adjust_link(phydev->attached_dev);
828
829                         } else if (0 == phydev->link_timeout--) {
830                                 int idx;
831
832                                 needs_aneg = 1;
833                                 /* If we have the magic_aneg bit,
834                                  * we try again */
835                                 if (phydev->drv->flags & PHY_HAS_MAGICANEG)
836                                         break;
837
838                                 /* The timer expired, and we still
839                                  * don't have a setting, so we try
840                                  * forcing it until we find one that
841                                  * works, starting from the fastest speed,
842                                  * and working our way down */
843                                 idx = phy_find_valid(0, phydev->supported);
844
845                                 phydev->speed = settings[idx].speed;
846                                 phydev->duplex = settings[idx].duplex;
847
848                                 phydev->autoneg = AUTONEG_DISABLE;
849
850                                 pr_info("Trying %d/%s\n", phydev->speed,
851                                                 DUPLEX_FULL ==
852                                                 phydev->duplex ?
853                                                 "FULL" : "HALF");
854                         }
855                         break;
856                 case PHY_NOLINK:
857                         err = phy_read_status(phydev);
858
859                         if (err)
860                                 break;
861
862                         if (phydev->link) {
863                                 phydev->state = PHY_RUNNING;
864                                 netif_carrier_on(phydev->attached_dev);
865                                 phydev->adjust_link(phydev->attached_dev);
866                         }
867                         break;
868                 case PHY_FORCING:
869                         err = genphy_update_link(phydev);
870
871                         if (err)
872                                 break;
873
874                         if (phydev->link) {
875                                 phydev->state = PHY_RUNNING;
876                                 netif_carrier_on(phydev->attached_dev);
877                         } else {
878                                 if (0 == phydev->link_timeout--) {
879                                         phy_force_reduction(phydev);
880                                         needs_aneg = 1;
881                                 }
882                         }
883
884                         phydev->adjust_link(phydev->attached_dev);
885                         break;
886                 case PHY_RUNNING:
887                         /* Only register a CHANGE if we are
888                          * polling */
889                         if (PHY_POLL == phydev->irq)
890                                 phydev->state = PHY_CHANGELINK;
891                         break;
892                 case PHY_CHANGELINK:
893                         err = phy_read_status(phydev);
894
895                         if (err)
896                                 break;
897
898                         if (phydev->link) {
899                                 phydev->state = PHY_RUNNING;
900                                 netif_carrier_on(phydev->attached_dev);
901                         } else {
902                                 phydev->state = PHY_NOLINK;
903                                 netif_carrier_off(phydev->attached_dev);
904                         }
905
906                         phydev->adjust_link(phydev->attached_dev);
907
908                         if (PHY_POLL != phydev->irq)
909                                 err = phy_config_interrupt(phydev,
910                                                 PHY_INTERRUPT_ENABLED);
911                         break;
912                 case PHY_HALTED:
913                         if (phydev->link) {
914                                 phydev->link = 0;
915                                 netif_carrier_off(phydev->attached_dev);
916                                 phydev->adjust_link(phydev->attached_dev);
917                         }
918                         break;
919                 case PHY_RESUMING:
920
921                         err = phy_clear_interrupt(phydev);
922
923                         if (err)
924                                 break;
925
926                         err = phy_config_interrupt(phydev,
927                                         PHY_INTERRUPT_ENABLED);
928
929                         if (err)
930                                 break;
931
932                         if (AUTONEG_ENABLE == phydev->autoneg) {
933                                 err = phy_aneg_done(phydev);
934                                 if (err < 0)
935                                         break;
936
937                                 /* err > 0 if AN is done.
938                                  * Otherwise, it's 0, and we're
939                                  * still waiting for AN */
940                                 if (err > 0) {
941                                         phydev->state = PHY_RUNNING;
942                                 } else {
943                                         phydev->state = PHY_AN;
944                                         phydev->link_timeout = PHY_AN_TIMEOUT;
945                                 }
946                         } else
947                                 phydev->state = PHY_RUNNING;
948                         break;
949         }
950
951         spin_unlock(&phydev->lock);
952
953         if (needs_aneg)
954                 err = phy_start_aneg(phydev);
955
956         if (err < 0)
957                 phy_error(phydev);
958
959         mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
960 }
961