drivers/net/phy/mdio_bus.c

   1 /*
   2  * drivers/net/phy/mdio_bus.c
   3  *
   4  * MDIO Bus interface
   5  *
   6  * Author: Andy Fleming
   7  *
   8  * Copyright (c) 2004 Freescale Semiconductor, Inc.
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  *
  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/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/spinlock.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
  35 #include <asm/io.h>
  36 #include <asm/irq.h>
  37 #include <asm/uaccess.h>
  38
  39 /**
  40  * mdiobus_alloc_size - allocate a mii_bus structure
  41  * @size: extra amount of memory to allocate for private storage.
  42  * If non-zero, then bus->priv is points to that memory.
  43  *
  44  * Description: called by a bus driver to allocate an mii_bus
  45  * structure to fill in.
  46  */
  47 struct mii_bus *mdiobus_alloc_size(size_t size)
  48 {
  49         struct mii_bus *bus;
  50         size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
  51         size_t alloc_size;
  52
  53         /* If we alloc extra space, it should be aligned */
  54         if (size)
  55                 alloc_size = aligned_size + size;
  56         else
  57                 alloc_size = sizeof(*bus);
  58
  59         bus = kzalloc(alloc_size, GFP_KERNEL);
  60         if (bus) {
  61                 bus->state = MDIOBUS_ALLOCATED;
  62                 if (size)
  63                         bus->priv = (void *)bus + aligned_size;
  64         }
  65
  66         return bus;
  67 }
  68 EXPORT_SYMBOL(mdiobus_alloc_size);
  69
  70 /**
  71  * mdiobus_release - mii_bus device release callback
  72  * @d: the target struct device that contains the mii_bus
  73  *
  74  * Description: called when the last reference to an mii_bus is
  75  * dropped, to free the underlying memory.
  76  */
  77 static void mdiobus_release(struct device *d)
  78 {
  79         struct mii_bus *bus = to_mii_bus(d);
  80         BUG_ON(bus->state != MDIOBUS_RELEASED &&
  81                /* for compatibility with error handling in drivers */
  82                bus->state != MDIOBUS_ALLOCATED);
  83         kfree(bus);
  84 }
  85
  86 static struct class mdio_bus_class = {
  87         .name           = "mdio_bus",
  88         .dev_release    = mdiobus_release,
  89 };
  90
  91 #if IS_ENABLED(CONFIG_OF_MDIO)
  92 /* Helper function for of_mdio_find_bus */
  93 static int of_mdio_bus_match(struct device *dev, void *mdio_bus_np)
  94 {
  95         return dev->of_node == mdio_bus_np;
  96 }
  97 /**
  98  * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
  99  * @mdio_bus_np: Pointer to the mii_bus.
 100  *
 101  * Returns a pointer to the mii_bus, or NULL if none found.
 102  *
 103  * Because the association of a device_node and mii_bus is made via
 104  * of_mdiobus_register(), the mii_bus cannot be found before it is
 105  * registered with of_mdiobus_register().
 106  *
 107  */
 108 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
 109 {
 110         struct device *d;
 111
 112         if (!mdio_bus_np)
 113                 return NULL;
 114
 115         d = class_find_device(&mdio_bus_class, NULL,  mdio_bus_np,
 116                               of_mdio_bus_match);
 117
 118         return d ? to_mii_bus(d) : NULL;
 119 }
 120 EXPORT_SYMBOL(of_mdio_find_bus);
 121 #endif
 122
 123 /**
 124  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 125  * @bus: target mii_bus
 126  *
 127  * Description: Called by a bus driver to bring up all the PHYs
 128  *   on a given bus, and attach them to the bus.
 129  *
 130  * Returns 0 on success or < 0 on error.
 131  */
 132 int mdiobus_register(struct mii_bus *bus)
 133 {
 134         int i, err;
 135
 136         if (NULL == bus || NULL == bus->name ||
 137                         NULL == bus->read ||
 138                         NULL == bus->write)
 139                 return -EINVAL;
 140
 141         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
 142                bus->state != MDIOBUS_UNREGISTERED);
 143
 144         bus->dev.parent = bus->parent;
 145         bus->dev.class = &mdio_bus_class;
 146         bus->dev.groups = NULL;
 147         dev_set_name(&bus->dev, "%s", bus->id);
 148
 149         err = device_register(&bus->dev);
 150         if (err) {
 151                 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
 152                 return -EINVAL;
 153         }
 154
 155         mutex_init(&bus->mdio_lock);
 156
 157         if (bus->reset)
 158                 bus->reset(bus);
 159
 160         for (i = 0; i < PHY_MAX_ADDR; i++) {
 161                 if ((bus->phy_mask & (1 << i)) == 0) {
 162                         struct phy_device *phydev;
 163
 164                         phydev = mdiobus_scan(bus, i);
 165                         if (IS_ERR(phydev)) {
 166                                 err = PTR_ERR(phydev);
 167                                 goto error;
 168                         }
 169                 }
 170         }
 171
 172         bus->state = MDIOBUS_REGISTERED;
 173         pr_info("%s: probed\n", bus->name);
 174         return 0;
 175
 176 error:
 177         while (--i >= 0) {
 178                 if (bus->phy_map[i])
 179                         device_unregister(&bus->phy_map[i]->dev);
 180         }
 181         device_del(&bus->dev);
 182         return err;
 183 }
 184 EXPORT_SYMBOL(mdiobus_register);
 185
 186 void mdiobus_unregister(struct mii_bus *bus)
 187 {
 188         int i;
 189
 190         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 191         bus->state = MDIOBUS_UNREGISTERED;
 192
 193         device_del(&bus->dev);
 194         for (i = 0; i < PHY_MAX_ADDR; i++) {
 195                 if (bus->phy_map[i])
 196                         device_unregister(&bus->phy_map[i]->dev);
 197                 bus->phy_map[i] = NULL;
 198         }
 199 }
 200 EXPORT_SYMBOL(mdiobus_unregister);
 201
 202 /**
 203  * mdiobus_free - free a struct mii_bus
 204  * @bus: mii_bus to free
 205  *
 206  * This function releases the reference to the underlying device
 207  * object in the mii_bus.  If this is the last reference, the mii_bus
 208  * will be freed.
 209  */
 210 void mdiobus_free(struct mii_bus *bus)
 211 {
 212         /*
 213          * For compatibility with error handling in drivers.
 214          */
 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);
 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         return ((phydrv->phy_id & phydrv->phy_id_mask) ==
 309                 (phydev->phy_id & phydrv->phy_id_mask));
 310 }
 311
 312 #ifdef CONFIG_PM
 313
 314 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 315 {
 316         struct device_driver *drv = phydev->dev.driver;
 317         struct phy_driver *phydrv = to_phy_driver(drv);
 318         struct net_device *netdev = phydev->attached_dev;
 319
 320         if (!drv || !phydrv->suspend)
 321                 return false;
 322
 323         /* PHY not attached? May suspend. */
 324         if (!netdev)
 325                 return true;
 326
 327         /*
 328          * Don't suspend PHY if the attched netdev parent may wakeup.
 329          * The parent may point to a PCI device, as in tg3 driver.
 330          */
 331         if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
 332                 return false;
 333
 334         /*
 335          * Also don't suspend PHY if the netdev itself may wakeup. This
 336          * is the case for devices w/o underlaying pwr. mgmt. aware bus,
 337          * e.g. SoC devices.
 338          */
 339         if (device_may_wakeup(&netdev->dev))
 340                 return false;
 341
 342         return true;
 343 }
 344
 345 static int mdio_bus_suspend(struct device *dev)
 346 {
 347         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 348         struct phy_device *phydev = to_phy_device(dev);
 349
 350         /*
 351          * We must stop the state machine manually, otherwise it stops out of
 352          * control, possibly with the phydev->lock held. Upon resume, netdev
 353          * may call phy routines that try to grab the same lock, and that may
 354          * lead to a deadlock.
 355          */
 356         if (phydev->attached_dev && phydev->adjust_link)
 357                 phy_stop_machine(phydev);
 358
 359         if (!mdio_bus_phy_may_suspend(phydev))
 360                 return 0;
 361
 362         return phydrv->suspend(phydev);
 363 }
 364
 365 static int mdio_bus_resume(struct device *dev)
 366 {
 367         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 368         struct phy_device *phydev = to_phy_device(dev);
 369         int ret;
 370
 371         if (!mdio_bus_phy_may_suspend(phydev))
 372                 goto no_resume;
 373
 374         ret = phydrv->resume(phydev);
 375         if (ret < 0)
 376                 return ret;
 377
 378 no_resume:
 379         if (phydev->attached_dev && phydev->adjust_link)
 380                 phy_start_machine(phydev, NULL);
 381
 382         return 0;
 383 }
 384
 385 static int mdio_bus_restore(struct device *dev)
 386 {
 387         struct phy_device *phydev = to_phy_device(dev);
 388         struct net_device *netdev = phydev->attached_dev;
 389         int ret;
 390
 391         if (!netdev)
 392                 return 0;
 393
 394         ret = phy_init_hw(phydev);
 395         if (ret < 0)
 396                 return ret;
 397
 398         /* The PHY needs to renegotiate. */
 399         phydev->link = 0;
 400         phydev->state = PHY_UP;
 401
 402         phy_start_machine(phydev, NULL);
 403
 404         return 0;
 405 }
 406
 407 static struct dev_pm_ops mdio_bus_pm_ops = {
 408         .suspend = mdio_bus_suspend,
 409         .resume = mdio_bus_resume,
 410         .freeze = mdio_bus_suspend,
 411         .thaw = mdio_bus_resume,
 412         .restore = mdio_bus_restore,
 413 };
 414
 415 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
 416
 417 #else
 418
 419 #define MDIO_BUS_PM_OPS NULL
 420
 421 #endif /* CONFIG_PM */
 422
 423 struct bus_type mdio_bus_type = {
 424         .name           = "mdio_bus",
 425         .match          = mdio_bus_match,
 426         .pm             = MDIO_BUS_PM_OPS,
 427 };
 428 EXPORT_SYMBOL(mdio_bus_type);
 429
 430 int __init mdio_bus_init(void)
 431 {
 432         int ret;
 433
 434         ret = class_register(&mdio_bus_class);
 435         if (!ret) {
 436                 ret = bus_register(&mdio_bus_type);
 437                 if (ret)
 438                         class_unregister(&mdio_bus_class);
 439         }
 440
 441         return ret;
 442 }
 443
 444 void mdio_bus_exit(void)
 445 {
 446         class_unregister(&mdio_bus_class);
 447         bus_unregister(&mdio_bus_type);
 448 }