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/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/atomic.h>
  39 #include <asm/io.h>
  40 #include <asm/irq.h>
  41 #include <asm/uaccess.h>
  42
  43 /**
  44  * phy_print_status - Convenience function to print out the current phy status
  45  * @phydev: the phy_device struct
  46  */
  47 void phy_print_status(struct phy_device *phydev)
  48 {
  49         pr_info("PHY: %s - Link is %s", phydev->dev.bus_id,
  50                         phydev->link ? "Up" : "Down");
  51         if (phydev->link)
  52                 printk(" - %d/%s", phydev->speed,
  53                                 DUPLEX_FULL == phydev->duplex ?
  54                                 "Full" : "Half");
  55
  56         printk("\n");
  57 }
  58 EXPORT_SYMBOL(phy_print_status);
  59
  60
  61 /**
  62  * phy_read - Convenience function for reading a given PHY register
  63  * @phydev: the phy_device struct
  64  * @regnum: register number to read
  65  *
  66  * NOTE: MUST NOT be called from interrupt context,
  67  * because the bus read/write functions may wait for an interrupt
  68  * to conclude the operation.
  69  */
  70 int phy_read(struct phy_device *phydev, u16 regnum)
  71 {
  72         int retval;
  73         struct mii_bus *bus = phydev->bus;
  74
  75         spin_lock_bh(&bus->mdio_lock);
  76         retval = bus->read(bus, phydev->addr, regnum);
  77         spin_unlock_bh(&bus->mdio_lock);
  78
  79         return retval;
  80 }
  81 EXPORT_SYMBOL(phy_read);
  82
  83 /**
  84  * phy_write - Convenience function for writing a given PHY register
  85  * @phydev: the phy_device struct
  86  * @regnum: register number to write
  87  * @val: value to write to @regnum
  88  *
  89  * NOTE: MUST NOT be called from interrupt context,
  90  * because the bus read/write functions may wait for an interrupt
  91  * to conclude the operation.
  92  */
  93 int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
  94 {
  95         int err;
  96         struct mii_bus *bus = phydev->bus;
  97
  98         spin_lock_bh(&bus->mdio_lock);
  99         err = bus->write(bus, phydev->addr, regnum, val);
 100         spin_unlock_bh(&bus->mdio_lock);
 101
 102         return err;
 103 }
 104 EXPORT_SYMBOL(phy_write);
 105
 106 /**
 107  * phy_clear_interrupt - Ack the phy device's interrupt
 108  * @phydev: the phy_device struct
 109  *
 110  * If the @phydev driver has an ack_interrupt function, call it to
 111  * ack and clear the phy device's interrupt.
 112  *
 113  * Returns 0 on success on < 0 on error.
 114  */
 115 int phy_clear_interrupt(struct phy_device *phydev)
 116 {
 117         int err = 0;
 118
 119         if (phydev->drv->ack_interrupt)
 120                 err = phydev->drv->ack_interrupt(phydev);
 121
 122         return err;
 123 }
 124
 125 /**
 126  * phy_config_interrupt - configure the PHY device for the requested interrupts
 127  * @phydev: the phy_device struct
 128  * @interrupts: interrupt flags to configure for this @phydev
 129  *
 130  * Returns 0 on success on < 0 on error.
 131  */
 132 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
 133 {
 134         int err = 0;
 135
 136         phydev->interrupts = interrupts;
 137         if (phydev->drv->config_intr)
 138                 err = phydev->drv->config_intr(phydev);
 139
 140         return err;
 141 }
 142
 143
 144 /**
 145  * phy_aneg_done - return auto-negotiation status
 146  * @phydev: target phy_device struct
 147  *
 148  * Description: Reads the status register and returns 0 either if
 149  *   auto-negotiation is incomplete, or if there was an error.
 150  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
 151  */
 152 static inline int phy_aneg_done(struct phy_device *phydev)
 153 {
 154         int retval;
 155
 156         retval = phy_read(phydev, MII_BMSR);
 157
 158         return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
 159 }
 160
 161 /* A structure for mapping a particular speed and duplex
 162  * combination to a particular SUPPORTED and ADVERTISED value */
 163 struct phy_setting {
 164         int speed;
 165         int duplex;
 166         u32 setting;
 167 };
 168
 169 /* A mapping of all SUPPORTED settings to speed/duplex */
 170 static const struct phy_setting settings[] = {
 171         {
 172                 .speed = 10000,
 173                 .duplex = DUPLEX_FULL,
 174                 .setting = SUPPORTED_10000baseT_Full,
 175         },
 176         {
 177                 .speed = SPEED_1000,
 178                 .duplex = DUPLEX_FULL,
 179                 .setting = SUPPORTED_1000baseT_Full,
 180         },
 181         {
 182                 .speed = SPEED_1000,
 183                 .duplex = DUPLEX_HALF,
 184                 .setting = SUPPORTED_1000baseT_Half,
 185         },
 186         {
 187                 .speed = SPEED_100,
 188                 .duplex = DUPLEX_FULL,
 189                 .setting = SUPPORTED_100baseT_Full,
 190         },
 191         {
 192                 .speed = SPEED_100,
 193                 .duplex = DUPLEX_HALF,
 194                 .setting = SUPPORTED_100baseT_Half,
 195         },
 196         {
 197                 .speed = SPEED_10,
 198                 .duplex = DUPLEX_FULL,
 199                 .setting = SUPPORTED_10baseT_Full,
 200         },
 201         {
 202                 .speed = SPEED_10,
 203                 .duplex = DUPLEX_HALF,
 204                 .setting = SUPPORTED_10baseT_Half,
 205         },
 206 };
 207
 208 #define MAX_NUM_SETTINGS ARRAY_SIZE(settings)
 209
 210 /**
 211  * phy_find_setting - find a PHY settings array entry that matches speed & duplex
 212  * @speed: speed to match
 213  * @duplex: duplex to match
 214  *
 215  * Description: Searches the settings array for the setting which
 216  *   matches the desired speed and duplex, and returns the index
 217  *   of that setting.  Returns the index of the last setting if
 218  *   none of the others match.
 219  */
 220 static inline int phy_find_setting(int speed, int duplex)
 221 {
 222         int idx = 0;
 223
 224         while (idx < ARRAY_SIZE(settings) &&
 225                         (settings[idx].speed != speed ||
 226                         settings[idx].duplex != duplex))
 227                 idx++;
 228
 229         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
 230 }
 231
 232 /**
 233  * phy_find_valid - find a PHY setting that matches the requested features mask
 234  * @idx: The first index in settings[] to search
 235  * @features: A mask of the valid settings
 236  *
 237  * Description: Returns the index of the first valid setting less
 238  *   than or equal to the one pointed to by idx, as determined by
 239  *   the mask in features.  Returns the index of the last setting
 240  *   if nothing else matches.
 241  */
 242 static inline int phy_find_valid(int idx, u32 features)
 243 {
 244         while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
 245                 idx++;
 246
 247         return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
 248 }
 249
 250 /**
 251  * phy_sanitize_settings - make sure the PHY is set to supported speed and duplex
 252  * @phydev: the target phy_device struct
 253  *
 254  * Description: Make sure the PHY is set to supported speeds and
 255  *   duplexes.  Drop down by one in this order:  1000/FULL,
 256  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
 257  */
 258 void phy_sanitize_settings(struct phy_device *phydev)
 259 {
 260         u32 features = phydev->supported;
 261         int idx;
 262
 263         /* Sanitize settings based on PHY capabilities */
 264         if ((features & SUPPORTED_Autoneg) == 0)
 265                 phydev->autoneg = AUTONEG_DISABLE;
 266
 267         idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
 268                         features);
 269
 270         phydev->speed = settings[idx].speed;
 271         phydev->duplex = settings[idx].duplex;
 272 }
 273 EXPORT_SYMBOL(phy_sanitize_settings);
 274
 275 /**
 276  * phy_ethtool_sset - generic ethtool sset function, handles all the details
 277  * @phydev: target phy_device struct
 278  * @cmd: ethtool_cmd
 279  *
 280  * A few notes about parameter checking:
 281  * - We don't set port or transceiver, so we don't care what they
 282  *   were set to.
 283  * - phy_start_aneg() will make sure forced settings are sane, and
 284  *   choose the next best ones from the ones selected, so we don't
 285  *   care if ethtool tries to give us bad values.
 286  */
 287 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 288 {
 289         if (cmd->phy_address != phydev->addr)
 290                 return -EINVAL;
 291
 292         /* We make sure that we don't pass unsupported
 293          * values in to the PHY */
 294         cmd->advertising &= phydev->supported;
 295
 296         /* Verify the settings we care about. */
 297         if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
 298                 return -EINVAL;
 299
 300         if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
 301                 return -EINVAL;
 302
 303         if (cmd->autoneg == AUTONEG_DISABLE
 304                         && ((cmd->speed != SPEED_1000
 305                                         && cmd->speed != SPEED_100
 306                                         && cmd->speed != SPEED_10)
 307                                 || (cmd->duplex != DUPLEX_HALF
 308                                         && cmd->duplex != DUPLEX_FULL)))
 309                 return -EINVAL;
 310
 311         phydev->autoneg = cmd->autoneg;
 312
 313         phydev->speed = cmd->speed;
 314
 315         phydev->advertising = cmd->advertising;
 316
 317         if (AUTONEG_ENABLE == cmd->autoneg)
 318                 phydev->advertising |= ADVERTISED_Autoneg;
 319         else
 320                 phydev->advertising &= ~ADVERTISED_Autoneg;
 321
 322         phydev->duplex = cmd->duplex;
 323
 324         /* Restart the PHY */
 325         phy_start_aneg(phydev);
 326
 327         return 0;
 328 }
 329 EXPORT_SYMBOL(phy_ethtool_sset);
 330
 331 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 332 {
 333         cmd->supported = phydev->supported;
 334
 335         cmd->advertising = phydev->advertising;
 336
 337         cmd->speed = phydev->speed;
 338         cmd->duplex = phydev->duplex;
 339         cmd->port = PORT_MII;
 340         cmd->phy_address = phydev->addr;
 341         cmd->transceiver = XCVR_EXTERNAL;
 342         cmd->autoneg = phydev->autoneg;
 343
 344         return 0;
 345 }
 346 EXPORT_SYMBOL(phy_ethtool_gset);
 347
 348 /**
 349  * phy_mii_ioctl - generic PHY MII ioctl interface
 350  * @phydev: the phy_device struct
 351  * @mii_data: MII ioctl data
 352  * @cmd: ioctl cmd to execute
 353  *
 354  * Note that this function is currently incompatible with the
 355  * PHYCONTROL layer.  It changes registers without regard to
 356  * current state.  Use at own risk.
 357  */
 358 int phy_mii_ioctl(struct phy_device *phydev,
 359                 struct mii_ioctl_data *mii_data, int cmd)
 360 {
 361         u16 val = mii_data->val_in;
 362
 363         switch (cmd) {
 364         case SIOCGMIIPHY:
 365                 mii_data->phy_id = phydev->addr;
 366                 break;
 367         case SIOCGMIIREG:
 368                 mii_data->val_out = phy_read(phydev, mii_data->reg_num);
 369                 break;
 370
 371         case SIOCSMIIREG:
 372                 if (!capable(CAP_NET_ADMIN))
 373                         return -EPERM;
 374
 375                 if (mii_data->phy_id == phydev->addr) {
 376                         switch(mii_data->reg_num) {
 377                         case MII_BMCR:
 378                                 if ((val & (BMCR_RESET|BMCR_ANENABLE)) == 0)
 379                                         phydev->autoneg = AUTONEG_DISABLE;
 380                                 else
 381                                         phydev->autoneg = AUTONEG_ENABLE;
 382                                 if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
 383                                         phydev->duplex = DUPLEX_FULL;
 384                                 else
 385                                         phydev->duplex = DUPLEX_HALF;
 386                                 if ((!phydev->autoneg) &&
 387                                                 (val & BMCR_SPEED1000))
 388                                         phydev->speed = SPEED_1000;
 389                                 else if ((!phydev->autoneg) &&
 390                                                 (val & BMCR_SPEED100))
 391                                         phydev->speed = SPEED_100;
 392                                 break;
 393                         case MII_ADVERTISE:
 394                                 phydev->advertising = val;
 395                                 break;
 396                         default:
 397                                 /* do nothing */
 398                                 break;
 399                         }
 400                 }
 401
 402                 phy_write(phydev, mii_data->reg_num, val);
 403
 404                 if (mii_data->reg_num == MII_BMCR
 405                                 && val & BMCR_RESET
 406                                 && phydev->drv->config_init)
 407                         phydev->drv->config_init(phydev);
 408                 break;
 409         }
 410
 411         return 0;
 412 }
 413 EXPORT_SYMBOL(phy_mii_ioctl);
 414
 415 /**
 416  * phy_start_aneg - start auto-negotiation for this PHY device
 417  * @phydev: the phy_device struct
 418  *
 419  * Description: Sanitizes the settings (if we're not autonegotiating
 420  *   them), and then calls the driver's config_aneg function.
 421  *   If the PHYCONTROL Layer is operating, we change the state to
 422  *   reflect the beginning of Auto-negotiation or forcing.
 423  */
 424 int phy_start_aneg(struct phy_device *phydev)
 425 {
 426         int err;
 427
 428         spin_lock_bh(&phydev->lock);
 429
 430         if (AUTONEG_DISABLE == phydev->autoneg)
 431                 phy_sanitize_settings(phydev);
 432
 433         err = phydev->drv->config_aneg(phydev);
 434
 435         if (err < 0)
 436                 goto out_unlock;
 437
 438         if (phydev->state != PHY_HALTED) {
 439                 if (AUTONEG_ENABLE == phydev->autoneg) {
 440                         phydev->state = PHY_AN;
 441                         phydev->link_timeout = PHY_AN_TIMEOUT;
 442                 } else {
 443                         phydev->state = PHY_FORCING;
 444                         phydev->link_timeout = PHY_FORCE_TIMEOUT;
 445                 }
 446         }
 447
 448 out_unlock:
 449         spin_unlock_bh(&phydev->lock);
 450         return err;
 451 }
 452 EXPORT_SYMBOL(phy_start_aneg);
 453
 454
 455 static void phy_change(struct work_struct *work);
 456 static void phy_timer(unsigned long data);
 457
 458 /**
 459  * phy_start_machine - start PHY state machine tracking
 460  * @phydev: the phy_device struct
 461  * @handler: callback function for state change notifications
 462  *
 463  * Description: The PHY infrastructure can run a state machine
 464  *   which tracks whether the PHY is starting up, negotiating,
 465  *   etc.  This function starts the timer which tracks the state
 466  *   of the PHY.  If you want to be notified when the state changes,
 467  *   pass in the callback @handler, otherwise, pass NULL.  If you
 468  *   want to maintain your own state machine, do not call this
 469  *   function.
 470  */
 471 void phy_start_machine(struct phy_device *phydev,
 472                 void (*handler)(struct net_device *))
 473 {
 474         phydev->adjust_state = handler;
 475
 476         init_timer(&phydev->phy_timer);
 477         phydev->phy_timer.function = &phy_timer;
 478         phydev->phy_timer.data = (unsigned long) phydev;
 479         mod_timer(&phydev->phy_timer, jiffies + HZ);
 480 }
 481
 482 /**
 483  * phy_stop_machine - stop the PHY state machine tracking
 484  * @phydev: target phy_device struct
 485  *
 486  * Description: Stops the state machine timer, sets the state to UP
 487  *   (unless it wasn't up yet). This function must be called BEFORE
 488  *   phy_detach.
 489  */
 490 void phy_stop_machine(struct phy_device *phydev)
 491 {
 492         del_timer_sync(&phydev->phy_timer);
 493
 494         spin_lock_bh(&phydev->lock);
 495         if (phydev->state > PHY_UP)
 496                 phydev->state = PHY_UP;
 497         spin_unlock_bh(&phydev->lock);
 498
 499         phydev->adjust_state = NULL;
 500 }
 501
 502 /**
 503  * phy_force_reduction - reduce PHY speed/duplex settings by one step
 504  * @phydev: target phy_device struct
 505  *
 506  * Description: Reduces the speed/duplex settings by one notch,
 507  *   in this order--
 508  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
 509  *   The function bottoms out at 10/HALF.
 510  */
 511 static void phy_force_reduction(struct phy_device *phydev)
 512 {
 513         int idx;
 514
 515         idx = phy_find_setting(phydev->speed, phydev->duplex);
 516
 517         idx++;
 518
 519         idx = phy_find_valid(idx, phydev->supported);
 520
 521         phydev->speed = settings[idx].speed;
 522         phydev->duplex = settings[idx].duplex;
 523
 524         pr_info("Trying %d/%s\n", phydev->speed,
 525                         DUPLEX_FULL == phydev->duplex ?
 526                         "FULL" : "HALF");
 527 }
 528
 529
 530 /**
 531  * phy_error - enter HALTED state for this PHY device
 532  * @phydev: target phy_device struct
 533  *
 534  * Moves the PHY to the HALTED state in response to a read
 535  * or write error, and tells the controller the link is down.
 536  * Must not be called from interrupt context, or while the
 537  * phydev->lock is held.
 538  */
 539 void phy_error(struct phy_device *phydev)
 540 {
 541         spin_lock_bh(&phydev->lock);
 542         phydev->state = PHY_HALTED;
 543         spin_unlock_bh(&phydev->lock);
 544 }
 545
 546 /**
 547  * phy_interrupt - PHY interrupt handler
 548  * @irq: interrupt line
 549  * @phy_dat: phy_device pointer
 550  *
 551  * Description: When a PHY interrupt occurs, the handler disables
 552  * interrupts, and schedules a work task to clear the interrupt.
 553  */
 554 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 555 {
 556         struct phy_device *phydev = phy_dat;
 557
 558         if (PHY_HALTED == phydev->state)
 559                 return IRQ_NONE;                /* It can't be ours.  */
 560
 561         /* The MDIO bus is not allowed to be written in interrupt
 562          * context, so we need to disable the irq here.  A work
 563          * queue will write the PHY to disable and clear the
 564          * interrupt, and then reenable the irq line. */
 565         disable_irq_nosync(irq);
 566         atomic_inc(&phydev->irq_disable);
 567
 568         schedule_work(&phydev->phy_queue);
 569
 570         return IRQ_HANDLED;
 571 }
 572
 573 /**
 574  * phy_enable_interrupts - Enable the interrupts from the PHY side
 575  * @phydev: target phy_device struct
 576  */
 577 int phy_enable_interrupts(struct phy_device *phydev)
 578 {
 579         int err;
 580
 581         err = phy_clear_interrupt(phydev);
 582
 583         if (err < 0)
 584                 return err;
 585
 586         err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 587
 588         return err;
 589 }
 590 EXPORT_SYMBOL(phy_enable_interrupts);
 591
 592 /**
 593  * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
 594  * @phydev: target phy_device struct
 595  */
 596 int phy_disable_interrupts(struct phy_device *phydev)
 597 {
 598         int err;
 599
 600         /* Disable PHY interrupts */
 601         err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
 602
 603         if (err)
 604                 goto phy_err;
 605
 606         /* Clear the interrupt */
 607         err = phy_clear_interrupt(phydev);
 608
 609         if (err)
 610                 goto phy_err;
 611
 612         return 0;
 613
 614 phy_err:
 615         phy_error(phydev);
 616
 617         return err;
 618 }
 619 EXPORT_SYMBOL(phy_disable_interrupts);
 620
 621 /**
 622  * phy_start_interrupts - request and enable interrupts for a PHY device
 623  * @phydev: target phy_device struct
 624  *
 625  * Description: Request the interrupt for the given PHY.
 626  *   If this fails, then we set irq to PHY_POLL.
 627  *   Otherwise, we enable the interrupts in the PHY.
 628  *   This should only be called with a valid IRQ number.
 629  *   Returns 0 on success or < 0 on error.
 630  */
 631 int phy_start_interrupts(struct phy_device *phydev)
 632 {
 633         int err = 0;
 634
 635         INIT_WORK(&phydev->phy_queue, phy_change);
 636
 637         atomic_set(&phydev->irq_disable, 0);
 638         if (request_irq(phydev->irq, phy_interrupt,
 639                                 IRQF_SHARED,
 640                                 "phy_interrupt",
 641                                 phydev) < 0) {
 642                 printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
 643                                 phydev->bus->name,
 644                                 phydev->irq);
 645                 phydev->irq = PHY_POLL;
 646                 return 0;
 647         }
 648
 649         err = phy_enable_interrupts(phydev);
 650
 651         return err;
 652 }
 653 EXPORT_SYMBOL(phy_start_interrupts);
 654
 655 /**
 656  * phy_stop_interrupts - disable interrupts from a PHY device
 657  * @phydev: target phy_device struct
 658  */
 659 int phy_stop_interrupts(struct phy_device *phydev)
 660 {
 661         int err;
 662
 663         err = phy_disable_interrupts(phydev);
 664
 665         if (err)
 666                 phy_error(phydev);
 667
 668         free_irq(phydev->irq, phydev);
 669
 670         /*
 671          * Cannot call flush_scheduled_work() here as desired because
 672          * of rtnl_lock(), but we do not really care about what would
 673          * be done, except from enable_irq(), so cancel any work
 674          * possibly pending and take care of the matter below.
 675          */
 676         cancel_work_sync(&phydev->phy_queue);
 677         /*
 678          * If work indeed has been cancelled, disable_irq() will have
 679          * been left unbalanced from phy_interrupt() and enable_irq()
 680          * has to be called so that other devices on the line work.
 681          */
 682         while (atomic_dec_return(&phydev->irq_disable) >= 0)
 683                 enable_irq(phydev->irq);
 684
 685         return err;
 686 }
 687 EXPORT_SYMBOL(phy_stop_interrupts);
 688
 689
 690 /**
 691  * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
 692  * @work: work_struct that describes the work to be done
 693  */
 694 static void phy_change(struct work_struct *work)
 695 {
 696         int err;
 697         struct phy_device *phydev =
 698                 container_of(work, struct phy_device, phy_queue);
 699
 700         err = phy_disable_interrupts(phydev);
 701
 702         if (err)
 703                 goto phy_err;
 704
 705         spin_lock_bh(&phydev->lock);
 706         if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
 707                 phydev->state = PHY_CHANGELINK;
 708         spin_unlock_bh(&phydev->lock);
 709
 710         atomic_dec(&phydev->irq_disable);
 711         enable_irq(phydev->irq);
 712
 713         /* Reenable interrupts */
 714         if (PHY_HALTED != phydev->state)
 715                 err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 716
 717         if (err)
 718                 goto irq_enable_err;
 719
 720         return;
 721
 722 irq_enable_err:
 723         disable_irq(phydev->irq);
 724         atomic_inc(&phydev->irq_disable);
 725 phy_err:
 726         phy_error(phydev);
 727 }
 728
 729 /**
 730  * phy_stop - Bring down the PHY link, and stop checking the status
 731  * @phydev: target phy_device struct
 732  */
 733 void phy_stop(struct phy_device *phydev)
 734 {
 735         spin_lock_bh(&phydev->lock);
 736
 737         if (PHY_HALTED == phydev->state)
 738                 goto out_unlock;
 739
 740         if (phydev->irq != PHY_POLL) {
 741                 /* Disable PHY Interrupts */
 742                 phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
 743
 744                 /* Clear any pending interrupts */
 745                 phy_clear_interrupt(phydev);
 746         }
 747
 748         phydev->state = PHY_HALTED;
 749
 750 out_unlock:
 751         spin_unlock_bh(&phydev->lock);
 752
 753         /*
 754          * Cannot call flush_scheduled_work() here as desired because
 755          * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
 756          * will not reenable interrupts.
 757          */
 758 }
 759
 760
 761 /**
 762  * phy_start - start or restart a PHY device
 763  * @phydev: target phy_device struct
 764  *
 765  * Description: Indicates the attached device's readiness to
 766  *   handle PHY-related work.  Used during startup to start the
 767  *   PHY, and after a call to phy_stop() to resume operation.
 768  *   Also used to indicate the MDIO bus has cleared an error
 769  *   condition.
 770  */
 771 void phy_start(struct phy_device *phydev)
 772 {
 773         spin_lock_bh(&phydev->lock);
 774
 775         switch (phydev->state) {
 776                 case PHY_STARTING:
 777                         phydev->state = PHY_PENDING;
 778                         break;
 779                 case PHY_READY:
 780                         phydev->state = PHY_UP;
 781                         break;
 782                 case PHY_HALTED:
 783                         phydev->state = PHY_RESUMING;
 784                 default:
 785                         break;
 786         }
 787         spin_unlock_bh(&phydev->lock);
 788 }
 789 EXPORT_SYMBOL(phy_stop);
 790 EXPORT_SYMBOL(phy_start);
 791
 792 /* PHY timer which handles the state machine */
 793 static void phy_timer(unsigned long data)
 794 {
 795         struct phy_device *phydev = (struct phy_device *)data;
 796         int needs_aneg = 0;
 797         int err = 0;
 798
 799         spin_lock_bh(&phydev->lock);
 800
 801         if (phydev->adjust_state)
 802                 phydev->adjust_state(phydev->attached_dev);
 803
 804         switch(phydev->state) {
 805                 case PHY_DOWN:
 806                 case PHY_STARTING:
 807                 case PHY_READY:
 808                 case PHY_PENDING:
 809                         break;
 810                 case PHY_UP:
 811                         needs_aneg = 1;
 812
 813                         phydev->link_timeout = PHY_AN_TIMEOUT;
 814
 815                         break;
 816                 case PHY_AN:
 817                         err = phy_read_status(phydev);
 818
 819                         if (err < 0)
 820                                 break;
 821
 822                         /* If the link is down, give up on
 823                          * negotiation for now */
 824                         if (!phydev->link) {
 825                                 phydev->state = PHY_NOLINK;
 826                                 netif_carrier_off(phydev->attached_dev);
 827                                 phydev->adjust_link(phydev->attached_dev);
 828                                 break;
 829                         }
 830
 831                         /* Check if negotiation is done.  Break
 832                          * if there's an error */
 833                         err = phy_aneg_done(phydev);
 834                         if (err < 0)
 835                                 break;
 836
 837                         /* If AN is done, we're running */
 838                         if (err > 0) {
 839                                 phydev->state = PHY_RUNNING;
 840                                 netif_carrier_on(phydev->attached_dev);
 841                                 phydev->adjust_link(phydev->attached_dev);
 842
 843                         } else if (0 == phydev->link_timeout--) {
 844                                 int idx;
 845
 846                                 needs_aneg = 1;
 847                                 /* If we have the magic_aneg bit,
 848                                  * we try again */
 849                                 if (phydev->drv->flags & PHY_HAS_MAGICANEG)
 850                                         break;
 851
 852                                 /* The timer expired, and we still
 853                                  * don't have a setting, so we try
 854                                  * forcing it until we find one that
 855                                  * works, starting from the fastest speed,
 856                                  * and working our way down */
 857                                 idx = phy_find_valid(0, phydev->supported);
 858
 859                                 phydev->speed = settings[idx].speed;
 860                                 phydev->duplex = settings[idx].duplex;
 861
 862                                 phydev->autoneg = AUTONEG_DISABLE;
 863
 864                                 pr_info("Trying %d/%s\n", phydev->speed,
 865                                                 DUPLEX_FULL ==
 866                                                 phydev->duplex ?
 867                                                 "FULL" : "HALF");
 868                         }
 869                         break;
 870                 case PHY_NOLINK:
 871                         err = phy_read_status(phydev);
 872
 873                         if (err)
 874                                 break;
 875
 876                         if (phydev->link) {
 877                                 phydev->state = PHY_RUNNING;
 878                                 netif_carrier_on(phydev->attached_dev);
 879                                 phydev->adjust_link(phydev->attached_dev);
 880                         }
 881                         break;
 882                 case PHY_FORCING:
 883                         err = genphy_update_link(phydev);
 884
 885                         if (err)
 886                                 break;
 887
 888                         if (phydev->link) {
 889                                 phydev->state = PHY_RUNNING;
 890                                 netif_carrier_on(phydev->attached_dev);
 891                         } else {
 892                                 if (0 == phydev->link_timeout--) {
 893                                         phy_force_reduction(phydev);
 894                                         needs_aneg = 1;
 895                                 }
 896                         }
 897
 898                         phydev->adjust_link(phydev->attached_dev);
 899                         break;
 900                 case PHY_RUNNING:
 901                         /* Only register a CHANGE if we are
 902                          * polling */
 903                         if (PHY_POLL == phydev->irq)
 904                                 phydev->state = PHY_CHANGELINK;
 905                         break;
 906                 case PHY_CHANGELINK:
 907                         err = phy_read_status(phydev);
 908
 909                         if (err)
 910                                 break;
 911
 912                         if (phydev->link) {
 913                                 phydev->state = PHY_RUNNING;
 914                                 netif_carrier_on(phydev->attached_dev);
 915                         } else {
 916                                 phydev->state = PHY_NOLINK;
 917                                 netif_carrier_off(phydev->attached_dev);
 918                         }
 919
 920                         phydev->adjust_link(phydev->attached_dev);
 921
 922                         if (PHY_POLL != phydev->irq)
 923                                 err = phy_config_interrupt(phydev,
 924                                                 PHY_INTERRUPT_ENABLED);
 925                         break;
 926                 case PHY_HALTED:
 927                         if (phydev->link) {
 928                                 phydev->link = 0;
 929                                 netif_carrier_off(phydev->attached_dev);
 930                                 phydev->adjust_link(phydev->attached_dev);
 931                         }
 932                         break;
 933                 case PHY_RESUMING:
 934
 935                         err = phy_clear_interrupt(phydev);
 936
 937                         if (err)
 938                                 break;
 939
 940                         err = phy_config_interrupt(phydev,
 941                                         PHY_INTERRUPT_ENABLED);
 942
 943                         if (err)
 944                                 break;
 945
 946                         if (AUTONEG_ENABLE == phydev->autoneg) {
 947                                 err = phy_aneg_done(phydev);
 948                                 if (err < 0)
 949                                         break;
 950
 951                                 /* err > 0 if AN is done.
 952                                  * Otherwise, it's 0, and we're
 953                                  * still waiting for AN */
 954                                 if (err > 0) {
 955                                         phydev->state = PHY_RUNNING;
 956                                 } else {
 957                                         phydev->state = PHY_AN;
 958                                         phydev->link_timeout = PHY_AN_TIMEOUT;
 959                                 }
 960                         } else
 961                                 phydev->state = PHY_RUNNING;
 962                         break;
 963         }
 964
 965         spin_unlock_bh(&phydev->lock);
 966
 967         if (needs_aneg)
 968                 err = phy_start_aneg(phydev);
 969
 970         if (err < 0)
 971                 phy_error(phydev);
 972
 973         mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
 974 }
 975