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 /**
  42  * mdiobus_alloc_size - allocate a mii_bus structure
  43  * @size: extra amount of memory to allocate for private storage.
  44  * If non-zero, then bus->priv is points to that memory.
  45  *
  46  * Description: called by a bus driver to allocate an mii_bus
  47  * structure to fill in.
  48  */
  49 struct mii_bus *mdiobus_alloc_size(size_t size)
  50 {
  51         struct mii_bus *bus;
  52         size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
  53         size_t alloc_size;
  54
  55         /* If we alloc extra space, it should be aligned */
  56         if (size)
  57                 alloc_size = aligned_size + size;
  58         else
  59                 alloc_size = sizeof(*bus);
  60
  61         bus = kzalloc(alloc_size, GFP_KERNEL);
  62         if (bus) {
  63                 bus->state = MDIOBUS_ALLOCATED;
  64                 if (size)
  65                         bus->priv = (void *)bus + aligned_size;
  66         }
  67
  68         return bus;
  69 }
  70 EXPORT_SYMBOL(mdiobus_alloc_size);
  71
  72 /**
  73  * mdiobus_release - mii_bus device release callback
  74  * @d: the target struct device that contains the mii_bus
  75  *
  76  * Description: called when the last reference to an mii_bus is
  77  * dropped, to free the underlying memory.
  78  */
  79 static void mdiobus_release(struct device *d)
  80 {
  81         struct mii_bus *bus = to_mii_bus(d);
  82         BUG_ON(bus->state != MDIOBUS_RELEASED &&
  83                /* for compatibility with error handling in drivers */
  84                bus->state != MDIOBUS_ALLOCATED);
  85         kfree(bus);
  86 }
  87
  88 static struct class mdio_bus_class = {
  89         .name           = "mdio_bus",
  90         .dev_release    = mdiobus_release,
  91 };
  92
  93 #if IS_ENABLED(CONFIG_OF_MDIO)
  94 /* Helper function for of_mdio_find_bus */
  95 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
  96 {
  97         return dev->of_node == mdio_bus_np;
  98 }
  99 /**
 100  * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
 101  * @mdio_bus_np: Pointer to the mii_bus.
 102  *
 103  * Returns a pointer to the mii_bus, or NULL if none found.
 104  *
 105  * Because the association of a device_node and mii_bus is made via
 106  * of_mdiobus_register(), the mii_bus cannot be found before it is
 107  * registered with of_mdiobus_register().
 108  *
 109  */
 110 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
 111 {
 112         struct device *d;
 113
 114         if (!mdio_bus_np)
 115                 return NULL;
 116
 117         d = class_find_device(&mdio_bus_class, NULL,  mdio_bus_np,
 118                               of_mdio_bus_match);
 119
 120         return d ? to_mii_bus(d) : NULL;
 121 }
 122 EXPORT_SYMBOL(of_mdio_find_bus);
 123 #endif
 124
 125 /**
 126  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 127  * @bus: target mii_bus
 128  *
 129  * Description: Called by a bus driver to bring up all the PHYs
 130  *   on a given bus, and attach them to the bus.
 131  *
 132  * Returns 0 on success or < 0 on error.
 133  */
 134 int mdiobus_register(struct mii_bus *bus)
 135 {
 136         int i, err;
 137
 138         if (NULL == bus || NULL == bus->name ||
 139             NULL == bus->read || NULL == bus->write)
 140                 return -EINVAL;
 141
 142         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
 143                bus->state != MDIOBUS_UNREGISTERED);
 144
 145         bus->dev.parent = bus->parent;
 146         bus->dev.class = &mdio_bus_class;
 147         bus->dev.groups = NULL;
 148         dev_set_name(&bus->dev, "%s", bus->id);
 149
 150         err = device_register(&bus->dev);
 151         if (err) {
 152                 pr_err("mii_bus %s failed to register\n", bus->id);
 153                 put_device(&bus->dev);
 154                 return -EINVAL;
 155         }
 156
 157         mutex_init(&bus->mdio_lock);
 158
 159         if (bus->reset)
 160                 bus->reset(bus);
 161
 162         for (i = 0; i < PHY_MAX_ADDR; i++) {
 163                 if ((bus->phy_mask & (1 << i)) == 0) {
 164                         struct phy_device *phydev;
 165
 166                         phydev = mdiobus_scan(bus, i);
 167                         if (IS_ERR(phydev)) {
 168                                 err = PTR_ERR(phydev);
 169                                 goto error;
 170                         }
 171                 }
 172         }
 173
 174         bus->state = MDIOBUS_REGISTERED;
 175         pr_info("%s: probed\n", bus->name);
 176         return 0;
 177
 178 error:
 179         while (--i >= 0) {
 180                 if (bus->phy_map[i])
 181                         device_unregister(&bus->phy_map[i]->dev);
 182         }
 183         device_del(&bus->dev);
 184         return err;
 185 }
 186 EXPORT_SYMBOL(mdiobus_register);
 187
 188 void mdiobus_unregister(struct mii_bus *bus)
 189 {
 190         int i;
 191
 192         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 193         bus->state = MDIOBUS_UNREGISTERED;
 194
 195         device_del(&bus->dev);
 196         for (i = 0; i < PHY_MAX_ADDR; i++) {
 197                 if (bus->phy_map[i])
 198                         device_unregister(&bus->phy_map[i]->dev);
 199                 bus->phy_map[i] = NULL;
 200         }
 201 }
 202 EXPORT_SYMBOL(mdiobus_unregister);
 203
 204 /**
 205  * mdiobus_free - free a struct mii_bus
 206  * @bus: mii_bus to free
 207  *
 208  * This function releases the reference to the underlying device
 209  * object in the mii_bus.  If this is the last reference, the mii_bus
 210  * will be freed.
 211  */
 212 void mdiobus_free(struct mii_bus *bus)
 213 {
 214         /* For compatibility with error handling in drivers. */
 215         if (bus->state == MDIOBUS_ALLOCATED) {
 216                 kfree(bus);
 217                 return;
 218         }
 219
 220         BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 221         bus->state = MDIOBUS_RELEASED;
 222
 223         put_device(&bus->dev);
 224 }
 225 EXPORT_SYMBOL(mdiobus_free);
 226
 227 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 228 {
 229         struct phy_device *phydev;
 230         int err;
 231
 232         phydev = get_phy_device(bus, addr, false);
 233         if (IS_ERR(phydev) || phydev == NULL)
 234                 return phydev;
 235
 236         err = phy_device_register(phydev);
 237         if (err) {
 238                 phy_device_free(phydev);
 239                 return NULL;
 240         }
 241
 242         return phydev;
 243 }
 244 EXPORT_SYMBOL(mdiobus_scan);
 245
 246 /**
 247  * mdiobus_read - Convenience function for reading a given MII mgmt register
 248  * @bus: the mii_bus struct
 249  * @addr: the phy address
 250  * @regnum: register number to read
 251  *
 252  * NOTE: MUST NOT be called from interrupt context,
 253  * because the bus read/write functions may wait for an interrupt
 254  * to conclude the operation.
 255  */
 256 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 257 {
 258         int retval;
 259
 260         BUG_ON(in_interrupt());
 261
 262         mutex_lock(&bus->mdio_lock);
 263         retval = bus->read(bus, addr, regnum);
 264         mutex_unlock(&bus->mdio_lock);
 265
 266         return retval;
 267 }
 268 EXPORT_SYMBOL(mdiobus_read);
 269
 270 /**
 271  * mdiobus_write - Convenience function for writing a given MII mgmt register
 272  * @bus: the mii_bus struct
 273  * @addr: the phy address
 274  * @regnum: register number to write
 275  * @val: value to write to @regnum
 276  *
 277  * NOTE: MUST NOT be called from interrupt context,
 278  * because the bus read/write functions may wait for an interrupt
 279  * to conclude the operation.
 280  */
 281 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 282 {
 283         int err;
 284
 285         BUG_ON(in_interrupt());
 286
 287         mutex_lock(&bus->mdio_lock);
 288         err = bus->write(bus, addr, regnum, val);
 289         mutex_unlock(&bus->mdio_lock);
 290
 291         return err;
 292 }
 293 EXPORT_SYMBOL(mdiobus_write);
 294
 295 /**
 296  * mdio_bus_match - determine if given PHY driver supports the given PHY device
 297  * @dev: target PHY device
 298  * @drv: given PHY driver
 299  *
 300  * Description: Given a PHY device, and a PHY driver, return 1 if
 301  *   the driver supports the device.  Otherwise, return 0.
 302  */
 303 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 304 {
 305         struct phy_device *phydev = to_phy_device(dev);
 306         struct phy_driver *phydrv = to_phy_driver(drv);
 307
 308         if (of_driver_match_device(dev, drv))
 309                 return 1;
 310
 311         if (phydrv->match_phy_device)
 312                 return phydrv->match_phy_device(phydev);
 313
 314         return (phydrv->phy_id & phydrv->phy_id_mask) ==
 315                 (phydev->phy_id & phydrv->phy_id_mask);
 316 }
 317
 318 #ifdef CONFIG_PM
 319
 320 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 321 {
 322         struct device_driver *drv = phydev->dev.driver;
 323         struct phy_driver *phydrv = to_phy_driver(drv);
 324         struct net_device *netdev = phydev->attached_dev;
 325
 326         if (!drv || !phydrv->suspend)
 327                 return false;
 328
 329         /* PHY not attached? May suspend. */
 330         if (!netdev)
 331                 return true;
 332
 333         /* Don't suspend PHY if the attched netdev parent may wakeup.
 334          * The parent may point to a PCI device, as in tg3 driver.
 335          */
 336         if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
 337                 return false;
 338
 339         /* Also don't suspend PHY if the netdev itself may wakeup. This
 340          * is the case for devices w/o underlaying pwr. mgmt. aware bus,
 341          * e.g. SoC devices.
 342          */
 343         if (device_may_wakeup(&netdev->dev))
 344                 return false;
 345
 346         return true;
 347 }
 348
 349 static int mdio_bus_suspend(struct device *dev)
 350 {
 351         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 352         struct phy_device *phydev = to_phy_device(dev);
 353
 354         /* We must stop the state machine manually, otherwise it stops out of
 355          * control, possibly with the phydev->lock held. Upon resume, netdev
 356          * may call phy routines that try to grab the same lock, and that may
 357          * lead to a deadlock.
 358          */
 359         if (phydev->attached_dev && phydev->adjust_link)
 360                 phy_stop_machine(phydev);
 361
 362         if (!mdio_bus_phy_may_suspend(phydev))
 363                 return 0;
 364
 365         return phydrv->suspend(phydev);
 366 }
 367
 368 static int mdio_bus_resume(struct device *dev)
 369 {
 370         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 371         struct phy_device *phydev = to_phy_device(dev);
 372         int ret;
 373
 374         if (!mdio_bus_phy_may_suspend(phydev))
 375                 goto no_resume;
 376
 377         ret = phydrv->resume(phydev);
 378         if (ret < 0)
 379                 return ret;
 380
 381 no_resume:
 382         if (phydev->attached_dev && phydev->adjust_link)
 383                 phy_start_machine(phydev);
 384
 385         return 0;
 386 }
 387
 388 static int mdio_bus_restore(struct device *dev)
 389 {
 390         struct phy_device *phydev = to_phy_device(dev);
 391         struct net_device *netdev = phydev->attached_dev;
 392         int ret;
 393
 394         if (!netdev)
 395                 return 0;
 396
 397         ret = phy_init_hw(phydev);
 398         if (ret < 0)
 399                 return ret;
 400
 401         /* The PHY needs to renegotiate. */
 402         phydev->link = 0;
 403         phydev->state = PHY_UP;
 404
 405         phy_start_machine(phydev);
 406
 407         return 0;
 408 }
 409
 410 static const struct dev_pm_ops mdio_bus_pm_ops = {
 411         .suspend = mdio_bus_suspend,
 412         .resume = mdio_bus_resume,
 413         .freeze = mdio_bus_suspend,
 414         .thaw = mdio_bus_resume,
 415         .restore = mdio_bus_restore,
 416 };
 417
 418 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
 419
 420 #else
 421
 422 #define MDIO_BUS_PM_OPS NULL
 423
 424 #endif /* CONFIG_PM */
 425
 426 static ssize_t
 427 phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
 428 {
 429         struct phy_device *phydev = to_phy_device(dev);
 430
 431         return sprintf(buf, "0x%.8lx\n", (unsigned long)phydev->phy_id);
 432 }
 433 static DEVICE_ATTR_RO(phy_id);
 434
 435 static struct attribute *mdio_dev_attrs[] = {
 436         &dev_attr_phy_id.attr,
 437         NULL,
 438 };
 439 ATTRIBUTE_GROUPS(mdio_dev);
 440
 441 struct bus_type mdio_bus_type = {
 442         .name           = "mdio_bus",
 443         .match          = mdio_bus_match,
 444         .pm             = MDIO_BUS_PM_OPS,
 445         .dev_groups     = mdio_dev_groups,
 446 };
 447 EXPORT_SYMBOL(mdio_bus_type);
 448
 449 int __init mdio_bus_init(void)
 450 {
 451         int ret;
 452
 453         ret = class_register(&mdio_bus_class);
 454         if (!ret) {
 455                 ret = bus_register(&mdio_bus_type);
 456                 if (ret)
 457                         class_unregister(&mdio_bus_class);
 458         }
 459
 460         return ret;
 461 }
 462
 463 void mdio_bus_exit(void)
 464 {
 465         class_unregister(&mdio_bus_class);
 466         bus_unregister(&mdio_bus_type);
 467 }