drivers/net/phy/mdio_bus.c

   1 /* MDIO Bus interface
   2  *
   3  * Author: Andy Fleming
   4  *
   5  * Copyright (c) 2004 Freescale Semiconductor, Inc.
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  *
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/unistd.h>
  20 #include <linux/slab.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/init.h>
  23 #include <linux/delay.h>
  24 #include <linux/device.h>
  25 #include <linux/of_device.h>
  26 #include <linux/of_mdio.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/mm.h>
  32 #include <linux/module.h>
  33 #include <linux/mii.h>
  34 #include <linux/ethtool.h>
  35 #include <linux/phy.h>
  36 #include <linux/io.h>
  37 #include <linux/uaccess.h>
  38
  39 #include <asm/irq.h>
  40
  41 int mdiobus_register_device(struct mdio_device *mdiodev)
  42 {
  43         if (mdiodev->bus->mdio_map[mdiodev->addr])
  44                 return -EBUSY;
  45
  46         mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
  47
  48         return 0;
  49 }
  50 EXPORT_SYMBOL(mdiobus_register_device);
  51
  52 int mdiobus_unregister_device(struct mdio_device *mdiodev)
  53 {
  54         if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
  55                 return -EINVAL;
  56
  57         mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
  58
  59         return 0;
  60 }
  61 EXPORT_SYMBOL(mdiobus_unregister_device);
  62
  63 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
  64 {
  65         struct mdio_device *mdiodev = bus->mdio_map[addr];
  66
  67         if (!mdiodev)
  68                 return NULL;
  69
  70         if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
  71                 return NULL;
  72
  73         return container_of(mdiodev, struct phy_device, mdio);
  74 }
  75 EXPORT_SYMBOL(mdiobus_get_phy);
  76
  77 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
  78 {
  79         return bus->mdio_map[addr];
  80 }
  81 EXPORT_SYMBOL(mdiobus_is_registered_device);
  82
  83 /**
  84  * mdiobus_alloc_size - allocate a mii_bus structure
  85  * @size: extra amount of memory to allocate for private storage.
  86  * If non-zero, then bus->priv is points to that memory.
  87  *
  88  * Description: called by a bus driver to allocate an mii_bus
  89  * structure to fill in.
  90  */
  91 struct mii_bus *mdiobus_alloc_size(size_t size)
  92 {
  93         struct mii_bus *bus;
  94         size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
  95         size_t alloc_size;
  96         int i;
  97
  98         /* If we alloc extra space, it should be aligned */
  99         if (size)
 100                 alloc_size = aligned_size + size;
 101         else
 102                 alloc_size = sizeof(*bus);
 103
 104         bus = kzalloc(alloc_size, GFP_KERNEL);
 105         if (!bus)
 106                 return NULL;
 107
 108         bus->state = MDIOBUS_ALLOCATED;
 109         if (size)
 110                 bus->priv = (void *)bus + aligned_size;
 111
 112         /* Initialise the interrupts to polling */
 113         for (i = 0; i < PHY_MAX_ADDR; i++)
 114                 bus->irq[i] = PHY_POLL;
 115
 116         return bus;
 117 }
 118 EXPORT_SYMBOL(mdiobus_alloc_size);
 119
 120 static void _devm_mdiobus_free(struct device *dev, void *res)
 121 {
 122         mdiobus_free(*(struct mii_bus **)res);
 123 }
 124
 125 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
 126 {
 127         struct mii_bus **r = res;
 128
 129         if (WARN_ON(!r || !*r))
 130                 return 0;
 131
 132         return *r == data;
 133 }
 134
 135 /**
 136  * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
 137  * @dev:                Device to allocate mii_bus for
 138  * @sizeof_priv:        Space to allocate for private structure.
 139  *
 140  * Managed mdiobus_alloc_size. mii_bus allocated with this function is
 141  * automatically freed on driver detach.
 142  *
 143  * If an mii_bus allocated with this function needs to be freed separately,
 144  * devm_mdiobus_free() must be used.
 145  *
 146  * RETURNS:
 147  * Pointer to allocated mii_bus on success, NULL on failure.
 148  */
 149 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
 150 {
 151         struct mii_bus **ptr, *bus;
 152
 153         ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
 154         if (!ptr)
 155                 return NULL;
 156
 157         /* use raw alloc_dr for kmalloc caller tracing */
 158         bus = mdiobus_alloc_size(sizeof_priv);
 159         if (bus) {
 160                 *ptr = bus;
 161                 devres_add(dev, ptr);
 162         } else {
 163                 devres_free(ptr);
 164         }
 165
 166         return bus;
 167 }
 168 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
 169
 170 /**
 171  * devm_mdiobus_free - Resource-managed mdiobus_free()
 172  * @dev:                Device this mii_bus belongs to
 173  * @bus:                the mii_bus associated with the device
 174  *
 175  * Free mii_bus allocated with devm_mdiobus_alloc_size().
 176  */
 177 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
 178 {
 179         int rc;
 180
 181         rc = devres_release(dev, _devm_mdiobus_free,
 182                             devm_mdiobus_match, bus);
 183         WARN_ON(rc);
 184 }
 185 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
 186
 187 /**
 188  * mdiobus_release - mii_bus device release callback
 189  * @d: the target struct device that contains the mii_bus
 190  *
 191  * Description: called when the last reference to an mii_bus is
 192  * dropped, to free the underlying memory.
 193  */
 194 static void mdiobus_release(struct device *d)
 195 {
 196         struct mii_bus *bus = to_mii_bus(d);
 197         BUG_ON(bus->state != MDIOBUS_RELEASED &&
 198                /* for compatibility with error handling in drivers */
 199                bus->state != MDIOBUS_ALLOCATED);
 200         kfree(bus);
 201 }
 202
 203 static struct class mdio_bus_class = {
 204         .name           = "mdio_bus",
 205         .dev_release    = mdiobus_release,
 206 };
 207
 208 #if IS_ENABLED(CONFIG_OF_MDIO)
 209 /* Helper function for of_mdio_find_bus */
 210 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
 211 {
 212         return dev->of_node == mdio_bus_np;
 213 }
 214 /**
 215  * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
 216  * @mdio_bus_np: Pointer to the mii_bus.
 217  *
 218  * Returns a reference to the mii_bus, or NULL if none found.  The
 219  * embedded struct device will have its reference count incremented,
 220  * and this must be put once the bus is finished with.
 221  *
 222  * Because the association of a device_node and mii_bus is made via
 223  * of_mdiobus_register(), the mii_bus cannot be found before it is
 224  * registered with of_mdiobus_register().
 225  *
 226  */
 227 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
 228 {
 229         struct device *d;
 230
 231         if (!mdio_bus_np)
 232                 return NULL;
 233
 234         d = class_find_device(&mdio_bus_class, NULL,  mdio_bus_np,
 235                               of_mdio_bus_match);
 236
 237         return d ? to_mii_bus(d) : NULL;
 238 }
 239 EXPORT_SYMBOL(of_mdio_find_bus);
 240
 241 /* Walk the list of subnodes of a mdio bus and look for a node that
 242  * matches the mdio device's address with its 'reg' property. If
 243  * found, set the of_node pointer for the mdio device. This allows
 244  * auto-probed phy devices to be supplied with information passed in
 245  * via DT.
 246  */
 247 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
 248                                     struct mdio_device *mdiodev)
 249 {
 250         struct device *dev = &mdiodev->dev;
 251         struct device_node *child;
 252
 253         if (dev->of_node || !bus->dev.of_node)
 254                 return;
 255
 256         for_each_available_child_of_node(bus->dev.of_node, child) {
 257                 int addr;
 258                 int ret;
 259
 260                 ret = of_property_read_u32(child, "reg", &addr);
 261                 if (ret < 0) {
 262                         dev_err(dev, "%s has invalid MDIO address\n",
 263                                 child->full_name);
 264                         continue;
 265                 }
 266
 267                 /* A MDIO device must have a reg property in the range [0-31] */
 268                 if (addr >= PHY_MAX_ADDR) {
 269                         dev_err(dev, "%s MDIO address %i is too large\n",
 270                                 child->full_name, addr);
 271                         continue;
 272                 }
 273
 274                 if (addr == mdiodev->addr) {
 275                         dev->of_node = child;
 276                         return;
 277                 }
 278         }
 279 }
 280 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
 281 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
 282                                            struct mdio_device *mdiodev)
 283 {
 284 }
 285 #endif
 286
 287 /**
 288  * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 289  * @bus: target mii_bus
 290  * @owner: module containing bus accessor functions
 291  *
 292  * Description: Called by a bus driver to bring up all the PHYs
 293  *   on a given bus, and attach them to the bus. Drivers should use
 294  *   mdiobus_register() rather than __mdiobus_register() unless they
 295  *   need to pass a specific owner module. MDIO devices which are not
 296  *   PHYs will not be brought up by this function. They are expected to
 297  *   to be explicitly listed in DT and instantiated by of_mdiobus_register().
 298  *
 299  * Returns 0 on success or < 0 on error.
 300  */
 301 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 302 {
 303         struct mdio_device *mdiodev;
 304         int i, err;
 305
 306         if (NULL == bus || NULL == bus->name ||
 307             NULL == bus->read || NULL == bus->write)
 308                 return -EINVAL;
 309
 310         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
 311                bus->state != MDIOBUS_UNREGISTERED);
 312
 313         bus->owner = owner;
 314         bus->dev.parent = bus->parent;
 315         bus->dev.class = &mdio_bus_class;
 316         bus->dev.groups = NULL;
 317         dev_set_name(&bus->dev, "%s", bus->id);
 318
 319         err = device_register(&bus->dev);
 320         if (err) {
 321                 pr_err("mii_bus %s failed to register\n", bus->id);
 322                 put_device(&bus->dev);
 323                 return -EINVAL;
 324         }
 325
 326         mutex_init(&bus->mdio_lock);
 327
 328         if (bus->reset)
 329                 bus->reset(bus);
 330
 331         for (i = 0; i < PHY_MAX_ADDR; i++) {
 332                 if ((bus->phy_mask & (1 << i)) == 0) {
 333                         struct phy_device *phydev;
 334
 335                         phydev = mdiobus_scan(bus, i);
 336                         if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
 337                                 err = PTR_ERR(phydev);
 338                                 goto error;
 339                         }
 340                 }
 341         }
 342
 343         bus->state = MDIOBUS_REGISTERED;
 344         pr_info("%s: probed\n", bus->name);
 345         return 0;
 346
 347 error:
 348         while (--i >= 0) {
 349                 mdiodev = bus->mdio_map[i];
 350                 if (!mdiodev)
 351                         continue;
 352
 353                 mdiodev->device_remove(mdiodev);
 354                 mdiodev->device_free(mdiodev);
 355         }
 356         device_del(&bus->dev);
 357         return err;
 358 }
 359 EXPORT_SYMBOL(__mdiobus_register);
 360
 361 void mdiobus_unregister(struct mii_bus *bus)
 362 {
 363         struct mdio_device *mdiodev;
 364         int i;
 365
 366         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 367         bus->state = MDIOBUS_UNREGISTERED;
 368
 369         for (i = 0; i < PHY_MAX_ADDR; i++) {
 370                 mdiodev = bus->mdio_map[i];
 371                 if (!mdiodev)
 372                         continue;
 373
 374                 mdiodev->device_remove(mdiodev);
 375                 mdiodev->device_free(mdiodev);
 376         }
 377         device_del(&bus->dev);
 378 }
 379 EXPORT_SYMBOL(mdiobus_unregister);
 380
 381 /**
 382  * mdiobus_free - free a struct mii_bus
 383  * @bus: mii_bus to free
 384  *
 385  * This function releases the reference to the underlying device
 386  * object in the mii_bus.  If this is the last reference, the mii_bus
 387  * will be freed.
 388  */
 389 void mdiobus_free(struct mii_bus *bus)
 390 {
 391         /* For compatibility with error handling in drivers. */
 392         if (bus->state == MDIOBUS_ALLOCATED) {
 393                 kfree(bus);
 394                 return;
 395         }
 396
 397         BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 398         bus->state = MDIOBUS_RELEASED;
 399
 400         put_device(&bus->dev);
 401 }
 402 EXPORT_SYMBOL(mdiobus_free);
 403
 404 /**
 405  * mdiobus_scan - scan a bus for MDIO devices.
 406  * @bus: mii_bus to scan
 407  * @addr: address on bus to scan
 408  *
 409  * This function scans the MDIO bus, looking for devices which can be
 410  * identified using a vendor/product ID in registers 2 and 3. Not all
 411  * MDIO devices have such registers, but PHY devices typically
 412  * do. Hence this function assumes anything found is a PHY, or can be
 413  * treated as a PHY. Other MDIO devices, such as switches, will
 414  * probably not be found during the scan.
 415  */
 416 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 417 {
 418         struct phy_device *phydev;
 419         int err;
 420
 421         phydev = get_phy_device(bus, addr, false);
 422         if (IS_ERR(phydev))
 423                 return phydev;
 424
 425         /*
 426          * For DT, see if the auto-probed phy has a correspoding child
 427          * in the bus node, and set the of_node pointer in this case.
 428          */
 429         of_mdiobus_link_mdiodev(bus, &phydev->mdio);
 430
 431         err = phy_device_register(phydev);
 432         if (err) {
 433                 phy_device_free(phydev);
 434                 return ERR_PTR(-ENODEV);
 435         }
 436
 437         return phydev;
 438 }
 439 EXPORT_SYMBOL(mdiobus_scan);
 440
 441 /**
 442  * mdiobus_read_nested - Nested version of the mdiobus_read function
 443  * @bus: the mii_bus struct
 444  * @addr: the phy address
 445  * @regnum: register number to read
 446  *
 447  * In case of nested MDIO bus access avoid lockdep false positives by
 448  * using mutex_lock_nested().
 449  *
 450  * NOTE: MUST NOT be called from interrupt context,
 451  * because the bus read/write functions may wait for an interrupt
 452  * to conclude the operation.
 453  */
 454 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
 455 {
 456         int retval;
 457
 458         BUG_ON(in_interrupt());
 459
 460         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 461         retval = bus->read(bus, addr, regnum);
 462         mutex_unlock(&bus->mdio_lock);
 463
 464         return retval;
 465 }
 466 EXPORT_SYMBOL(mdiobus_read_nested);
 467
 468 /**
 469  * mdiobus_read - Convenience function for reading a given MII mgmt register
 470  * @bus: the mii_bus struct
 471  * @addr: the phy address
 472  * @regnum: register number to read
 473  *
 474  * NOTE: MUST NOT be called from interrupt context,
 475  * because the bus read/write functions may wait for an interrupt
 476  * to conclude the operation.
 477  */
 478 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 479 {
 480         int retval;
 481
 482         BUG_ON(in_interrupt());
 483
 484         mutex_lock(&bus->mdio_lock);
 485         retval = bus->read(bus, addr, regnum);
 486         mutex_unlock(&bus->mdio_lock);
 487
 488         return retval;
 489 }
 490 EXPORT_SYMBOL(mdiobus_read);
 491
 492 /**
 493  * mdiobus_write_nested - Nested version of the mdiobus_write function
 494  * @bus: the mii_bus struct
 495  * @addr: the phy address
 496  * @regnum: register number to write
 497  * @val: value to write to @regnum
 498  *
 499  * In case of nested MDIO bus access avoid lockdep false positives by
 500  * using mutex_lock_nested().
 501  *
 502  * NOTE: MUST NOT be called from interrupt context,
 503  * because the bus read/write functions may wait for an interrupt
 504  * to conclude the operation.
 505  */
 506 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 507 {
 508         int err;
 509
 510         BUG_ON(in_interrupt());
 511
 512         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 513         err = bus->write(bus, addr, regnum, val);
 514         mutex_unlock(&bus->mdio_lock);
 515
 516         return err;
 517 }
 518 EXPORT_SYMBOL(mdiobus_write_nested);
 519
 520 /**
 521  * mdiobus_write - Convenience function for writing a given MII mgmt register
 522  * @bus: the mii_bus struct
 523  * @addr: the phy address
 524  * @regnum: register number to write
 525  * @val: value to write to @regnum
 526  *
 527  * NOTE: MUST NOT be called from interrupt context,
 528  * because the bus read/write functions may wait for an interrupt
 529  * to conclude the operation.
 530  */
 531 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 532 {
 533         int err;
 534
 535         BUG_ON(in_interrupt());
 536
 537         mutex_lock(&bus->mdio_lock);
 538         err = bus->write(bus, addr, regnum, val);
 539         mutex_unlock(&bus->mdio_lock);
 540
 541         return err;
 542 }
 543 EXPORT_SYMBOL(mdiobus_write);
 544
 545 /**
 546  * mdio_bus_match - determine if given MDIO driver supports the given
 547  *                  MDIO device
 548  * @dev: target MDIO device
 549  * @drv: given MDIO driver
 550  *
 551  * Description: Given a MDIO device, and a MDIO driver, return 1 if
 552  *   the driver supports the device.  Otherwise, return 0. This may
 553  *   require calling the devices own match function, since different classes
 554  *   of MDIO devices have different match criteria.
 555  */
 556 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 557 {
 558         struct mdio_device *mdio = to_mdio_device(dev);
 559
 560         if (of_driver_match_device(dev, drv))
 561                 return 1;
 562
 563         if (mdio->bus_match)
 564                 return mdio->bus_match(dev, drv);
 565
 566         return 0;
 567 }
 568
 569 #ifdef CONFIG_PM
 570 static int mdio_bus_suspend(struct device *dev)
 571 {
 572         struct mdio_device *mdio = to_mdio_device(dev);
 573
 574         if (mdio->pm_ops && mdio->pm_ops->suspend)
 575                 return mdio->pm_ops->suspend(dev);
 576
 577         return 0;
 578 }
 579
 580 static int mdio_bus_resume(struct device *dev)
 581 {
 582         struct mdio_device *mdio = to_mdio_device(dev);
 583
 584         if (mdio->pm_ops && mdio->pm_ops->resume)
 585                 return mdio->pm_ops->resume(dev);
 586
 587         return 0;
 588 }
 589
 590 static int mdio_bus_restore(struct device *dev)
 591 {
 592         struct mdio_device *mdio = to_mdio_device(dev);
 593
 594         if (mdio->pm_ops && mdio->pm_ops->restore)
 595                 return mdio->pm_ops->restore(dev);
 596
 597         return 0;
 598 }
 599
 600 static const struct dev_pm_ops mdio_bus_pm_ops = {
 601         .suspend = mdio_bus_suspend,
 602         .resume = mdio_bus_resume,
 603         .freeze = mdio_bus_suspend,
 604         .thaw = mdio_bus_resume,
 605         .restore = mdio_bus_restore,
 606 };
 607
 608 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
 609
 610 #else
 611
 612 #define MDIO_BUS_PM_OPS NULL
 613
 614 #endif /* CONFIG_PM */
 615
 616 struct bus_type mdio_bus_type = {
 617         .name           = "mdio_bus",
 618         .match          = mdio_bus_match,
 619         .pm             = MDIO_BUS_PM_OPS,
 620 };
 621 EXPORT_SYMBOL(mdio_bus_type);
 622
 623 int __init mdio_bus_init(void)
 624 {
 625         int ret;
 626
 627         ret = class_register(&mdio_bus_class);
 628         if (!ret) {
 629                 ret = bus_register(&mdio_bus_type);
 630                 if (ret)
 631                         class_unregister(&mdio_bus_class);
 632         }
 633
 634         return ret;
 635 }
 636
 637 void mdio_bus_exit(void)
 638 {
 639         class_unregister(&mdio_bus_class);
 640         bus_unregister(&mdio_bus_type);
 641 }