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, 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", 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         BUG_ON(in_interrupt());
  75
  76         mutex_lock(&bus->mdio_lock);
  77         retval = bus->read(bus, phydev->addr, regnum);
  78         mutex_unlock(&bus->mdio_lock);
  79
  80         return retval;
  81 }
  82 EXPORT_SYMBOL(phy_read);
  83
  84 /**
  85  * phy_write - Convenience function for writing a given PHY register
  86  * @phydev: the phy_device struct
  87  * @regnum: register number to write
  88  * @val: value to write to @regnum
  89  *
  90  * NOTE: MUST NOT be called from interrupt context,
  91  * because the bus read/write functions may wait for an interrupt
  92  * to conclude the operation.
  93  */
  94 int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
  95 {
  96         int err;
  97         struct mii_bus *bus = phydev->bus;
  98
  99         BUG_ON(in_interrupt());
 100
 101         mutex_lock(&bus->mdio_lock);
 102         err = bus->write(bus, phydev->addr, regnum, val);
 103         mutex_unlock(&bus->mdio_lock);
 104
 105         return err;
 106 }
 107 EXPORT_SYMBOL(phy_write);
 108
 109 /**
 110  * phy_clear_interrupt - Ack the phy device's interrupt
 111  * @phydev: the phy_device struct
 112  *
 113  * If the @phydev driver has an ack_interrupt function, call it to
 114  * ack and clear the phy device's interrupt.
 115  *
 116  * Returns 0 on success on < 0 on error.
 117  */
 118 int phy_clear_interrupt(struct phy_device *phydev)
 119 {
 120         int err = 0;
 121
 122         if (phydev->drv->ack_interrupt)
 123                 err = phydev->drv->ack_interrupt(phydev);
 124
 125         return err;
 126 }
 127
 128 /**
 129  * phy_config_interrupt - configure the PHY device for the requested interrupts
 130  * @phydev: the phy_device struct
 131  * @interrupts: interrupt flags to configure for this @phydev
 132  *
 133  * Returns 0 on success on < 0 on error.
 134  */
 135 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
 136 {
 137         int err = 0;
 138
 139         phydev->interrupts = interrupts;
 140         if (phydev->drv->config_intr)
 141                 err = phydev->drv->config_intr(phydev);
 142
 143         return err;
 144 }
 145
 146
 147 /**
 148  * phy_aneg_done - return auto-negotiation status
 149  * @phydev: target phy_device struct
 150  *
 151  * Description: Reads the status register and returns 0 either if
 152  *   auto-negotiation is incomplete, or if there was an error.
 153  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
 154  */
 155 static inline int phy_aneg_done(struct phy_device *phydev)
 156 {
 157         int retval;
 158
 159         retval = phy_read(phydev, MII_BMSR);
 160
 161         return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
 162 }
 163
 164 /* A structure for mapping a particular speed and duplex
 165  * combination to a particular SUPPORTED and ADVERTISED value */
 166 struct phy_setting {
 167         int speed;
 168         int duplex;
 169         u32 setting;
 170 };
 171
 172 /* A mapping of all SUPPORTED settings to speed/duplex */
 173 static const struct phy_setting settings[] = {
 174         {
 175                 .speed = 10000,
 176                 .duplex = DUPLEX_FULL,
 177                 .setting = SUPPORTED_10000baseT_Full,
 178         },
 179         {
 180                 .speed = SPEED_1000,
 181                 .duplex = DUPLEX_FULL,
 182                 .setting = SUPPORTED_1000baseT_Full,
 183         },
 184         {
 185                 .speed = SPEED_1000,
 186                 .duplex = DUPLEX_HALF,
 187                 .setting = SUPPORTED_1000baseT_Half,
 188         },
 189         {
 190                 .speed = SPEED_100,
 191                 .duplex = DUPLEX_FULL,
 192                 .setting = SUPPORTED_100baseT_Full,
 193         },
 194         {
 195                 .speed = SPEED_100,
 196                 .duplex = DUPLEX_HALF,
 197                 .setting = SUPPORTED_100baseT_Half,
 198         },
 199         {
 200                 .speed = SPEED_10,
 201                 .duplex = DUPLEX_FULL,
 202                 .setting = SUPPORTED_10baseT_Full,
 203         },
 204         {
 205                 .speed = SPEED_10,
 206                 .duplex = DUPLEX_HALF,
 207                 .setting = SUPPORTED_10baseT_Half,
 208         },
 209 };
 210
 211 #define MAX_NUM_SETTINGS ARRAY_SIZE(settings)
 212
 213 /**
 214  * phy_find_setting - find a PHY settings array entry that matches speed & duplex
 215  * @speed: speed to match
 216  * @duplex: duplex to match
 217  *
 218  * Description: Searches the settings array for the setting which
 219  *   matches the desired speed and duplex, and returns the index
 220  *   of that setting.  Returns the index of the last setting if
 221  *   none of the others match.
 222  */
 223 static inline int phy_find_setting(int speed, int duplex)
 224 {
 225         int idx = 0;
 226
 227         while (idx < ARRAY_SIZE(settings) &&
 228                         (settings[idx].speed != speed ||
 229                         settings[idx].duplex != duplex))
 230                 idx++;
 231
 232         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
 233 }
 234
 235 /**
 236  * phy_find_valid - find a PHY setting that matches the requested features mask
 237  * @idx: The first index in settings[] to search
 238  * @features: A mask of the valid settings
 239  *
 240  * Description: Returns the index of the first valid setting less
 241  *   than or equal to the one pointed to by idx, as determined by
 242  *   the mask in features.  Returns the index of the last setting
 243  *   if nothing else matches.
 244  */
 245 static inline int phy_find_valid(int idx, u32 features)
 246 {
 247         while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
 248                 idx++;
 249
 250         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
 251 }
 252
 253 /**
 254  * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
 255  * @phydev: the target phy_device struct
 256  *
 257  * Description: Make sure the PHY is set to supported speeds and
 258  *   duplexes.  Drop down by one in this order:  1000/FULL,
 259  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
 260  */
 261 void phy_sanitize_settings(struct phy_device *phydev)
 262 {
 263         u32 features = phydev->supported;
 264         int idx;
 265
 266         /* Sanitize settings based on PHY capabilities */
 267         if ((features & SUPPORTED_Autoneg) == 0)
 268                 phydev->autoneg = AUTONEG_DISABLE;
 269
 270         idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
 271                         features);
 272
 273         phydev->speed = settings[idx].speed;
 274         phydev->duplex = settings[idx].duplex;
 275 }
 276 EXPORT_SYMBOL(phy_sanitize_settings);
 277
 278 /**
 279  * phy_ethtool_sset - generic ethtool sset function, handles all the details
 280  * @phydev: target phy_device struct
 281  * @cmd: ethtool_cmd
 282  *
 283  * A few notes about parameter checking:
 284  * - We don't set port or transceiver, so we don't care what they
 285  *   were set to.
 286  * - phy_start_aneg() will make sure forced settings are sane, and
 287  *   choose the next best ones from the ones selected, so we don't
 288  *   care if ethtool tries to give us bad values.
 289  */
 290 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 291 {
 292         if (cmd->phy_address != phydev->addr)
 293                 return -EINVAL;
 294
 295         /* We make sure that we don't pass unsupported
 296          * values in to the PHY */
 297         cmd->advertising &= phydev->supported;
 298
 299         /* Verify the settings we care about. */
 300         if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
 301                 return -EINVAL;
 302
 303         if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
 304                 return -EINVAL;
 305
 306         if (cmd->autoneg == AUTONEG_DISABLE
 307                         && ((cmd->speed != SPEED_1000
 308                                         && cmd->speed != SPEED_100
 309                                         && cmd->speed != SPEED_10)
 310                                 || (cmd->duplex != DUPLEX_HALF
 311                                         && cmd->duplex != DUPLEX_FULL)))
 312                 return -EINVAL;
 313
 314         phydev->autoneg = cmd->autoneg;
 315
 316         phydev->speed = cmd->speed;
 317
 318         phydev->advertising = cmd->advertising;
 319
 320         if (AUTONEG_ENABLE == cmd->autoneg)
 321                 phydev->advertising |= ADVERTISED_Autoneg;
 322         else
 323                 phydev->advertising &= ~ADVERTISED_Autoneg;
 324
 325         phydev->duplex = cmd->duplex;
 326
 327         /* Restart the PHY */
 328         phy_start_aneg(phydev);
 329
 330         return 0;
 331 }
 332 EXPORT_SYMBOL(phy_ethtool_sset);
 333
 334 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 335 {
 336         cmd->supported = phydev->supported;
 337
 338         cmd->advertising = phydev->advertising;
 339
 340         cmd->speed = phydev->speed;
 341         cmd->duplex = phydev->duplex;
 342         cmd->port = PORT_MII;
 343         cmd->phy_address = phydev->addr;
 344         cmd->transceiver = XCVR_EXTERNAL;
 345         cmd->autoneg = phydev->autoneg;
 346
 347         return 0;
 348 }
 349 EXPORT_SYMBOL(phy_ethtool_gset);
 350
 351 /**
 352  * phy_mii_ioctl - generic PHY MII ioctl interface
 353  * @phydev: the phy_device struct
 354  * @mii_data: MII ioctl data
 355  * @cmd: ioctl cmd to execute
 356  *
 357  * Note that this function is currently incompatible with the
 358  * PHYCONTROL layer.  It changes registers without regard to
 359  * current state.  Use at own risk.
 360  */
 361 int phy_mii_ioctl(struct phy_device *phydev,
 362                 struct mii_ioctl_data *mii_data, int cmd)
 363 {
 364         u16 val = mii_data->val_in;
 365
 366         switch (cmd) {
 367         case SIOCGMIIPHY:
 368                 mii_data->phy_id = phydev->addr;
 369                 /* fall through */
 370
 371         case SIOCGMIIREG:
 372                 mii_data->val_out = phy_read(phydev, mii_data->reg_num);
 373                 break;
 374
 375         case SIOCSMIIREG:
 376                 if (!capable(CAP_NET_ADMIN))
 377                         return -EPERM;
 378
 379                 if (mii_data->phy_id == phydev->addr) {
 380                         switch(mii_data->reg_num) {
 381                         case MII_BMCR:
 382                                 if ((val & (BMCR_RESET|BMCR_ANENABLE)) == 0)
 383                                         phydev->autoneg = AUTONEG_DISABLE;
 384                                 else
 385                                         phydev->autoneg = AUTONEG_ENABLE;
 386                                 if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
 387                                         phydev->duplex = DUPLEX_FULL;
 388                                 else
 389                                         phydev->duplex = DUPLEX_HALF;
 390                                 if ((!phydev->autoneg) &&
 391                                                 (val & BMCR_SPEED1000))
 392                                         phydev->speed = SPEED_1000;
 393                                 else if ((!phydev->autoneg) &&
 394                                                 (val & BMCR_SPEED100))
 395                                         phydev->speed = SPEED_100;
 396                                 break;
 397                         case MII_ADVERTISE:
 398                                 phydev->advertising = val;
 399                                 break;
 400                         default:
 401                                 /* do nothing */
 402                                 break;
 403                         }
 404                 }
 405
 406                 phy_write(phydev, mii_data->reg_num, val);
 407
 408                 if (mii_data->reg_num == MII_BMCR
 409                                 && val & BMCR_RESET
 410                                 && phydev->drv->config_init) {
 411                         phy_scan_fixups(phydev);
 412                         phydev->drv->config_init(phydev);
 413                 }
 414                 break;
 415
 416         default:
 417                 return -EOPNOTSUPP;
 418         }
 419
 420         return 0;
 421 }
 422 EXPORT_SYMBOL(phy_mii_ioctl);
 423
 424 /**
 425  * phy_start_aneg - start auto-negotiation for this PHY device
 426  * @phydev: the phy_device struct
 427  *
 428  * Description: Sanitizes the settings (if we're not autonegotiating
 429  *   them), and then calls the driver's config_aneg function.
 430  *   If the PHYCONTROL Layer is operating, we change the state to
 431  *   reflect the beginning of Auto-negotiation or forcing.
 432  */
 433 int phy_start_aneg(struct phy_device *phydev)
 434 {
 435         int err;
 436
 437         mutex_lock(&phydev->lock);
 438
 439         if (AUTONEG_DISABLE == phydev->autoneg)
 440                 phy_sanitize_settings(phydev);
 441
 442         err = phydev->drv->config_aneg(phydev);
 443
 444         if (err < 0)
 445                 goto out_unlock;
 446
 447         if (phydev->state != PHY_HALTED) {
 448                 if (AUTONEG_ENABLE == phydev->autoneg) {
 449                         phydev->state = PHY_AN;
 450                         phydev->link_timeout = PHY_AN_TIMEOUT;
 451                 } else {
 452                         phydev->state = PHY_FORCING;
 453                         phydev->link_timeout = PHY_FORCE_TIMEOUT;
 454                 }
 455         }
 456
 457 out_unlock:
 458         mutex_unlock(&phydev->lock);
 459         return err;
 460 }
 461 EXPORT_SYMBOL(phy_start_aneg);
 462
 463
 464 static void phy_change(struct work_struct *work);
 465 static void phy_state_machine(struct work_struct *work);
 466 static void phy_timer(unsigned long data);
 467
 468 /**
 469  * phy_start_machine - start PHY state machine tracking
 470  * @phydev: the phy_device struct
 471  * @handler: callback function for state change notifications
 472  *
 473  * Description: The PHY infrastructure can run a state machine
 474  *   which tracks whether the PHY is starting up, negotiating,
 475  *   etc.  This function starts the timer which tracks the state
 476  *   of the PHY.  If you want to be notified when the state changes,
 477  *   pass in the callback @handler, otherwise, pass NULL.  If you
 478  *   want to maintain your own state machine, do not call this
 479  *   function.
 480  */
 481 void phy_start_machine(struct phy_device *phydev,
 482                 void (*handler)(struct net_device *))
 483 {
 484         phydev->adjust_state = handler;
 485
 486         INIT_WORK(&phydev->state_queue, phy_state_machine);
 487         init_timer(&phydev->phy_timer);
 488         phydev->phy_timer.function = &phy_timer;
 489         phydev->phy_timer.data = (unsigned long) phydev;
 490         mod_timer(&phydev->phy_timer, jiffies + HZ);
 491 }
 492
 493 /**
 494  * phy_stop_machine - stop the PHY state machine tracking
 495  * @phydev: target phy_device struct
 496  *
 497  * Description: Stops the state machine timer, sets the state to UP
 498  *   (unless it wasn't up yet). This function must be called BEFORE
 499  *   phy_detach.
 500  */
 501 void phy_stop_machine(struct phy_device *phydev)
 502 {
 503         del_timer_sync(&phydev->phy_timer);
 504         cancel_work_sync(&phydev->state_queue);
 505
 506         mutex_lock(&phydev->lock);
 507         if (phydev->state > PHY_UP)
 508                 phydev->state = PHY_UP;
 509         mutex_unlock(&phydev->lock);
 510
 511         phydev->adjust_state = NULL;
 512 }
 513
 514 /**
 515  * phy_force_reduction - reduce PHY speed/duplex settings by one step
 516  * @phydev: target phy_device struct
 517  *
 518  * Description: Reduces the speed/duplex settings by one notch,
 519  *   in this order--
 520  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
 521  *   The function bottoms out at 10/HALF.
 522  */
 523 static void phy_force_reduction(struct phy_device *phydev)
 524 {
 525         int idx;
 526
 527         idx = phy_find_setting(phydev->speed, phydev->duplex);
 528
 529         idx++;
 530
 531         idx = phy_find_valid(idx, phydev->supported);
 532
 533         phydev->speed = settings[idx].speed;
 534         phydev->duplex = settings[idx].duplex;
 535
 536         pr_info("Trying %d/%s\n", phydev->speed,
 537                         DUPLEX_FULL == phydev->duplex ?
 538                         "FULL" : "HALF");
 539 }
 540
 541
 542 /**
 543  * phy_error - enter HALTED state for this PHY device
 544  * @phydev: target phy_device struct
 545  *
 546  * Moves the PHY to the HALTED state in response to a read
 547  * or write error, and tells the controller the link is down.
 548  * Must not be called from interrupt context, or while the
 549  * phydev->lock is held.
 550  */
 551 static void phy_error(struct phy_device *phydev)
 552 {
 553         mutex_lock(&phydev->lock);
 554         phydev->state = PHY_HALTED;
 555         mutex_unlock(&phydev->lock);
 556 }
 557
 558 /**
 559  * phy_interrupt - PHY interrupt handler
 560  * @irq: interrupt line
 561  * @phy_dat: phy_device pointer
 562  *
 563  * Description: When a PHY interrupt occurs, the handler disables
 564  * interrupts, and schedules a work task to clear the interrupt.
 565  */
 566 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 567 {
 568         struct phy_device *phydev = phy_dat;
 569
 570         if (PHY_HALTED == phydev->state)
 571                 return IRQ_NONE;                /* It can't be ours.  */
 572
 573         /* The MDIO bus is not allowed to be written in interrupt
 574          * context, so we need to disable the irq here.  A work
 575          * queue will write the PHY to disable and clear the
 576          * interrupt, and then reenable the irq line. */
 577         disable_irq_nosync(irq);
 578         atomic_inc(&phydev->irq_disable);
 579
 580         schedule_work(&phydev->phy_queue);
 581
 582         return IRQ_HANDLED;
 583 }
 584
 585 /**
 586  * phy_enable_interrupts - Enable the interrupts from the PHY side
 587  * @phydev: target phy_device struct
 588  */
 589 int phy_enable_interrupts(struct phy_device *phydev)
 590 {
 591         int err;
 592
 593         err = phy_clear_interrupt(phydev);
 594
 595         if (err < 0)
 596                 return err;
 597
 598         err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 599
 600         return err;
 601 }
 602 EXPORT_SYMBOL(phy_enable_interrupts);
 603
 604 /**
 605  * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
 606  * @phydev: target phy_device struct
 607  */
 608 int phy_disable_interrupts(struct phy_device *phydev)
 609 {
 610         int err;
 611
 612         /* Disable PHY interrupts */
 613         err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
 614
 615         if (err)
 616                 goto phy_err;
 617
 618         /* Clear the interrupt */
 619         err = phy_clear_interrupt(phydev);
 620
 621         if (err)
 622                 goto phy_err;
 623
 624         return 0;
 625
 626 phy_err:
 627         phy_error(phydev);
 628
 629         return err;
 630 }
 631 EXPORT_SYMBOL(phy_disable_interrupts);
 632
 633 /**
 634  * phy_start_interrupts - request and enable interrupts for a PHY device
 635  * @phydev: target phy_device struct
 636  *
 637  * Description: Request the interrupt for the given PHY.
 638  *   If this fails, then we set irq to PHY_POLL.
 639  *   Otherwise, we enable the interrupts in the PHY.
 640  *   This should only be called with a valid IRQ number.
 641  *   Returns 0 on success or < 0 on error.
 642  */
 643 int phy_start_interrupts(struct phy_device *phydev)
 644 {
 645         int err = 0;
 646
 647         INIT_WORK(&phydev->phy_queue, phy_change);
 648
 649         atomic_set(&phydev->irq_disable, 0);
 650         if (request_irq(phydev->irq, phy_interrupt,
 651                                 IRQF_SHARED,
 652                                 "phy_interrupt",
 653                                 phydev) < 0) {
 654                 printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
 655                                 phydev->bus->name,
 656                                 phydev->irq);
 657                 phydev->irq = PHY_POLL;
 658                 return 0;
 659         }
 660
 661         err = phy_enable_interrupts(phydev);
 662
 663         return err;
 664 }
 665 EXPORT_SYMBOL(phy_start_interrupts);
 666
 667 /**
 668  * phy_stop_interrupts - disable interrupts from a PHY device
 669  * @phydev: target phy_device struct
 670  */
 671 int phy_stop_interrupts(struct phy_device *phydev)
 672 {
 673         int err;
 674
 675         err = phy_disable_interrupts(phydev);
 676
 677         if (err)
 678                 phy_error(phydev);
 679
 680         free_irq(phydev->irq, phydev);
 681
 682         /*
 683          * Cannot call flush_scheduled_work() here as desired because
 684          * of rtnl_lock(), but we do not really care about what would
 685          * be done, except from enable_irq(), so cancel any work
 686          * possibly pending and take care of the matter below.
 687          */
 688         cancel_work_sync(&phydev->phy_queue);
 689         /*
 690          * If work indeed has been cancelled, disable_irq() will have
 691          * been left unbalanced from phy_interrupt() and enable_irq()
 692          * has to be called so that other devices on the line work.
 693          */
 694         while (atomic_dec_return(&phydev->irq_disable) >= 0)
 695                 enable_irq(phydev->irq);
 696
 697         return err;
 698 }
 699 EXPORT_SYMBOL(phy_stop_interrupts);
 700
 701
 702 /**
 703  * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
 704  * @work: work_struct that describes the work to be done
 705  */
 706 static void phy_change(struct work_struct *work)
 707 {
 708         int err;
 709         struct phy_device *phydev =
 710                 container_of(work, struct phy_device, phy_queue);
 711
 712         err = phy_disable_interrupts(phydev);
 713
 714         if (err)
 715                 goto phy_err;
 716
 717         mutex_lock(&phydev->lock);
 718         if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
 719                 phydev->state = PHY_CHANGELINK;
 720         mutex_unlock(&phydev->lock);
 721
 722         atomic_dec(&phydev->irq_disable);
 723         enable_irq(phydev->irq);
 724
 725         /* Reenable interrupts */
 726         if (PHY_HALTED != phydev->state)
 727                 err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 728
 729         if (err)
 730                 goto irq_enable_err;
 731
 732         /* Stop timer and run the state queue now.  The work function for
 733          * state_queue will start the timer up again.
 734          */
 735         del_timer(&phydev->phy_timer);
 736         schedule_work(&phydev->state_queue);
 737
 738         return;
 739
 740 irq_enable_err:
 741         disable_irq(phydev->irq);
 742         atomic_inc(&phydev->irq_disable);
 743 phy_err:
 744         phy_error(phydev);
 745 }
 746
 747 /**
 748  * phy_stop - Bring down the PHY link, and stop checking the status
 749  * @phydev: target phy_device struct
 750  */
 751 void phy_stop(struct phy_device *phydev)
 752 {
 753         mutex_lock(&phydev->lock);
 754
 755         if (PHY_HALTED == phydev->state)
 756                 goto out_unlock;
 757
 758         if (phydev->irq != PHY_POLL) {
 759                 /* Disable PHY Interrupts */
 760                 phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
 761
 762                 /* Clear any pending interrupts */
 763                 phy_clear_interrupt(phydev);
 764         }
 765
 766         phydev->state = PHY_HALTED;
 767
 768 out_unlock:
 769         mutex_unlock(&phydev->lock);
 770
 771         /*
 772          * Cannot call flush_scheduled_work() here as desired because
 773          * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
 774          * will not reenable interrupts.
 775          */
 776 }
 777
 778
 779 /**
 780  * phy_start - start or restart a PHY device
 781  * @phydev: target phy_device struct
 782  *
 783  * Description: Indicates the attached device's readiness to
 784  *   handle PHY-related work.  Used during startup to start the
 785  *   PHY, and after a call to phy_stop() to resume operation.
 786  *   Also used to indicate the MDIO bus has cleared an error
 787  *   condition.
 788  */
 789 void phy_start(struct phy_device *phydev)
 790 {
 791         mutex_lock(&phydev->lock);
 792
 793         switch (phydev->state) {
 794                 case PHY_STARTING:
 795                         phydev->state = PHY_PENDING;
 796                         break;
 797                 case PHY_READY:
 798                         phydev->state = PHY_UP;
 799                         break;
 800                 case PHY_HALTED:
 801                         phydev->state = PHY_RESUMING;
 802                 default:
 803                         break;
 804         }
 805         mutex_unlock(&phydev->lock);
 806 }
 807 EXPORT_SYMBOL(phy_stop);
 808 EXPORT_SYMBOL(phy_start);
 809
 810 /**
 811  * phy_state_machine - Handle the state machine
 812  * @work: work_struct that describes the work to be done
 813  *
 814  * Description: Scheduled by the state_queue workqueue each time
 815  *   phy_timer is triggered.
 816  */
 817 static void phy_state_machine(struct work_struct *work)
 818 {
 819         struct phy_device *phydev =
 820                         container_of(work, struct phy_device, state_queue);
 821         int needs_aneg = 0;
 822         int err = 0;
 823
 824         mutex_lock(&phydev->lock);
 825
 826         if (phydev->adjust_state)
 827                 phydev->adjust_state(phydev->attached_dev);
 828
 829         switch(phydev->state) {
 830                 case PHY_DOWN:
 831                 case PHY_STARTING:
 832                 case PHY_READY:
 833                 case PHY_PENDING:
 834                         break;
 835                 case PHY_UP:
 836                         needs_aneg = 1;
 837
 838                         phydev->link_timeout = PHY_AN_TIMEOUT;
 839
 840                         break;
 841                 case PHY_AN:
 842                         err = phy_read_status(phydev);
 843
 844                         if (err < 0)
 845                                 break;
 846
 847                         /* If the link is down, give up on
 848                          * negotiation for now */
 849                         if (!phydev->link) {
 850                                 phydev->state = PHY_NOLINK;
 851                                 netif_carrier_off(phydev->attached_dev);
 852                                 phydev->adjust_link(phydev->attached_dev);
 853                                 break;
 854                         }
 855
 856                         /* Check if negotiation is done.  Break
 857                          * if there's an error */
 858                         err = phy_aneg_done(phydev);
 859                         if (err < 0)
 860                                 break;
 861
 862                         /* If AN is done, we're running */
 863                         if (err > 0) {
 864                                 phydev->state = PHY_RUNNING;
 865                                 netif_carrier_on(phydev->attached_dev);
 866                                 phydev->adjust_link(phydev->attached_dev);
 867
 868                         } else if (0 == phydev->link_timeout--) {
 869                                 int idx;
 870
 871                                 needs_aneg = 1;
 872                                 /* If we have the magic_aneg bit,
 873                                  * we try again */
 874                                 if (phydev->drv->flags & PHY_HAS_MAGICANEG)
 875                                         break;
 876
 877                                 /* The timer expired, and we still
 878                                  * don't have a setting, so we try
 879                                  * forcing it until we find one that
 880                                  * works, starting from the fastest speed,
 881                                  * and working our way down */
 882                                 idx = phy_find_valid(0, phydev->supported);
 883
 884                                 phydev->speed = settings[idx].speed;
 885                                 phydev->duplex = settings[idx].duplex;
 886
 887                                 phydev->autoneg = AUTONEG_DISABLE;
 888
 889                                 pr_info("Trying %d/%s\n", phydev->speed,
 890                                                 DUPLEX_FULL ==
 891                                                 phydev->duplex ?
 892                                                 "FULL" : "HALF");
 893                         }
 894                         break;
 895                 case PHY_NOLINK:
 896                         err = phy_read_status(phydev);
 897
 898                         if (err)
 899                                 break;
 900
 901                         if (phydev->link) {
 902                                 phydev->state = PHY_RUNNING;
 903                                 netif_carrier_on(phydev->attached_dev);
 904                                 phydev->adjust_link(phydev->attached_dev);
 905                         }
 906                         break;
 907                 case PHY_FORCING:
 908                         err = genphy_update_link(phydev);
 909
 910                         if (err)
 911                                 break;
 912
 913                         if (phydev->link) {
 914                                 phydev->state = PHY_RUNNING;
 915                                 netif_carrier_on(phydev->attached_dev);
 916                         } else {
 917                                 if (0 == phydev->link_timeout--) {
 918                                         phy_force_reduction(phydev);
 919                                         needs_aneg = 1;
 920                                 }
 921                         }
 922
 923                         phydev->adjust_link(phydev->attached_dev);
 924                         break;
 925                 case PHY_RUNNING:
 926                         /* Only register a CHANGE if we are
 927                          * polling */
 928                         if (PHY_POLL == phydev->irq)
 929                                 phydev->state = PHY_CHANGELINK;
 930                         break;
 931                 case PHY_CHANGELINK:
 932                         err = phy_read_status(phydev);
 933
 934                         if (err)
 935                                 break;
 936
 937                         if (phydev->link) {
 938                                 phydev->state = PHY_RUNNING;
 939                                 netif_carrier_on(phydev->attached_dev);
 940                         } else {
 941                                 phydev->state = PHY_NOLINK;
 942                                 netif_carrier_off(phydev->attached_dev);
 943                         }
 944
 945                         phydev->adjust_link(phydev->attached_dev);
 946
 947                         if (PHY_POLL != phydev->irq)
 948                                 err = phy_config_interrupt(phydev,
 949                                                 PHY_INTERRUPT_ENABLED);
 950                         break;
 951                 case PHY_HALTED:
 952                         if (phydev->link) {
 953                                 phydev->link = 0;
 954                                 netif_carrier_off(phydev->attached_dev);
 955                                 phydev->adjust_link(phydev->attached_dev);
 956                         }
 957                         break;
 958                 case PHY_RESUMING:
 959
 960                         err = phy_clear_interrupt(phydev);
 961
 962                         if (err)
 963                                 break;
 964
 965                         err = phy_config_interrupt(phydev,
 966                                         PHY_INTERRUPT_ENABLED);
 967
 968                         if (err)
 969                                 break;
 970
 971                         if (AUTONEG_ENABLE == phydev->autoneg) {
 972                                 err = phy_aneg_done(phydev);
 973                                 if (err < 0)
 974                                         break;
 975
 976                                 /* err > 0 if AN is done.
 977                                  * Otherwise, it's 0, and we're
 978                                  * still waiting for AN */
 979                                 if (err > 0) {
 980                                         phydev->state = PHY_RUNNING;
 981                                 } else {
 982                                         phydev->state = PHY_AN;
 983                                         phydev->link_timeout = PHY_AN_TIMEOUT;
 984                                 }
 985                         } else
 986                                 phydev->state = PHY_RUNNING;
 987                         break;
 988         }
 989
 990         mutex_unlock(&phydev->lock);
 991
 992         if (needs_aneg)
 993                 err = phy_start_aneg(phydev);
 994
 995         if (err < 0)
 996                 phy_error(phydev);
 997
 998         mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
 999 }
1000
1001 /* PHY timer which schedules the state machine work */
1002 static void phy_timer(unsigned long data)
1003 {
1004         struct phy_device *phydev = (struct phy_device *)data;
1005
1006         /*
1007          * PHY I/O operations can potentially sleep so we ensure that
1008          * it's done from a process context
1009          */
1010         schedule_work(&phydev->state_queue);
1011 }