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 - allocate a mii_bus structure
  41  *
  42  * Description: called by a bus driver to allocate an mii_bus
  43  * structure to fill in.
  44  */
  45 struct mii_bus *mdiobus_alloc(void)
  46 {
  47         struct mii_bus *bus;
  48
  49         bus = kzalloc(sizeof(*bus), GFP_KERNEL);
  50         if (bus != NULL)
  51                 bus->state = MDIOBUS_ALLOCATED;
  52
  53         return bus;
  54 }
  55 EXPORT_SYMBOL(mdiobus_alloc);
  56
  57 /**
  58  * mdiobus_release - mii_bus device release callback
  59  * @d: the target struct device that contains the mii_bus
  60  *
  61  * Description: called when the last reference to an mii_bus is
  62  * dropped, to free the underlying memory.
  63  */
  64 static void mdiobus_release(struct device *d)
  65 {
  66         struct mii_bus *bus = to_mii_bus(d);
  67         BUG_ON(bus->state != MDIOBUS_RELEASED &&
  68                /* for compatibility with error handling in drivers */
  69                bus->state != MDIOBUS_ALLOCATED);
  70         kfree(bus);
  71 }
  72
  73 static struct class mdio_bus_class = {
  74         .name           = "mdio_bus",
  75         .dev_release    = mdiobus_release,
  76 };
  77
  78 /**
  79  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  80  * @bus: target mii_bus
  81  *
  82  * Description: Called by a bus driver to bring up all the PHYs
  83  *   on a given bus, and attach them to the bus.
  84  *
  85  * Returns 0 on success or < 0 on error.
  86  */
  87 int mdiobus_register(struct mii_bus *bus)
  88 {
  89         int i, err;
  90
  91         if (NULL == bus || NULL == bus->name ||
  92                         NULL == bus->read ||
  93                         NULL == bus->write)
  94                 return -EINVAL;
  95
  96         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
  97                bus->state != MDIOBUS_UNREGISTERED);
  98
  99         bus->dev.parent = bus->parent;
 100         bus->dev.class = &mdio_bus_class;
 101         bus->dev.groups = NULL;
 102         dev_set_name(&bus->dev, "%s", bus->id);
 103
 104         err = device_register(&bus->dev);
 105         if (err) {
 106                 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
 107                 return -EINVAL;
 108         }
 109
 110         mutex_init(&bus->mdio_lock);
 111
 112         if (bus->reset)
 113                 bus->reset(bus);
 114
 115         for (i = 0; i < PHY_MAX_ADDR; i++) {
 116                 if ((bus->phy_mask & (1 << i)) == 0) {
 117                         struct phy_device *phydev;
 118
 119                         phydev = mdiobus_scan(bus, i);
 120                         if (IS_ERR(phydev)) {
 121                                 err = PTR_ERR(phydev);
 122                                 goto error;
 123                         }
 124                 }
 125         }
 126
 127         bus->state = MDIOBUS_REGISTERED;
 128         pr_info("%s: probed\n", bus->name);
 129         return 0;
 130
 131 error:
 132         while (--i >= 0) {
 133                 if (bus->phy_map[i])
 134                         device_unregister(&bus->phy_map[i]->dev);
 135         }
 136         device_del(&bus->dev);
 137         return err;
 138 }
 139 EXPORT_SYMBOL(mdiobus_register);
 140
 141 void mdiobus_unregister(struct mii_bus *bus)
 142 {
 143         int i;
 144
 145         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 146         bus->state = MDIOBUS_UNREGISTERED;
 147
 148         device_del(&bus->dev);
 149         for (i = 0; i < PHY_MAX_ADDR; i++) {
 150                 if (bus->phy_map[i])
 151                         device_unregister(&bus->phy_map[i]->dev);
 152                 bus->phy_map[i] = NULL;
 153         }
 154 }
 155 EXPORT_SYMBOL(mdiobus_unregister);
 156
 157 /**
 158  * mdiobus_free - free a struct mii_bus
 159  * @bus: mii_bus to free
 160  *
 161  * This function releases the reference to the underlying device
 162  * object in the mii_bus.  If this is the last reference, the mii_bus
 163  * will be freed.
 164  */
 165 void mdiobus_free(struct mii_bus *bus)
 166 {
 167         /*
 168          * For compatibility with error handling in drivers.
 169          */
 170         if (bus->state == MDIOBUS_ALLOCATED) {
 171                 kfree(bus);
 172                 return;
 173         }
 174
 175         BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 176         bus->state = MDIOBUS_RELEASED;
 177
 178         put_device(&bus->dev);
 179 }
 180 EXPORT_SYMBOL(mdiobus_free);
 181
 182 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 183 {
 184         struct phy_device *phydev;
 185         int err;
 186
 187         phydev = get_phy_device(bus, addr);
 188         if (IS_ERR(phydev) || phydev == NULL)
 189                 return phydev;
 190
 191         err = phy_device_register(phydev);
 192         if (err) {
 193                 phy_device_free(phydev);
 194                 return NULL;
 195         }
 196
 197         return phydev;
 198 }
 199 EXPORT_SYMBOL(mdiobus_scan);
 200
 201 /**
 202  * mdiobus_read - Convenience function for reading a given MII mgmt register
 203  * @bus: the mii_bus struct
 204  * @addr: the phy address
 205  * @regnum: register number to read
 206  *
 207  * NOTE: MUST NOT be called from interrupt context,
 208  * because the bus read/write functions may wait for an interrupt
 209  * to conclude the operation.
 210  */
 211 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 212 {
 213         int retval;
 214
 215         BUG_ON(in_interrupt());
 216
 217         mutex_lock(&bus->mdio_lock);
 218         retval = bus->read(bus, addr, regnum);
 219         mutex_unlock(&bus->mdio_lock);
 220
 221         return retval;
 222 }
 223 EXPORT_SYMBOL(mdiobus_read);
 224
 225 /**
 226  * mdiobus_write - Convenience function for writing a given MII mgmt register
 227  * @bus: the mii_bus struct
 228  * @addr: the phy address
 229  * @regnum: register number to write
 230  * @val: value to write to @regnum
 231  *
 232  * NOTE: MUST NOT be called from interrupt context,
 233  * because the bus read/write functions may wait for an interrupt
 234  * to conclude the operation.
 235  */
 236 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 237 {
 238         int err;
 239
 240         BUG_ON(in_interrupt());
 241
 242         mutex_lock(&bus->mdio_lock);
 243         err = bus->write(bus, addr, regnum, val);
 244         mutex_unlock(&bus->mdio_lock);
 245
 246         return err;
 247 }
 248 EXPORT_SYMBOL(mdiobus_write);
 249
 250 /**
 251  * mdio_bus_match - determine if given PHY driver supports the given PHY device
 252  * @dev: target PHY device
 253  * @drv: given PHY driver
 254  *
 255  * Description: Given a PHY device, and a PHY driver, return 1 if
 256  *   the driver supports the device.  Otherwise, return 0.
 257  */
 258 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 259 {
 260         struct phy_device *phydev = to_phy_device(dev);
 261         struct phy_driver *phydrv = to_phy_driver(drv);
 262
 263         return ((phydrv->phy_id & phydrv->phy_id_mask) ==
 264                 (phydev->phy_id & phydrv->phy_id_mask));
 265 }
 266
 267 #ifdef CONFIG_PM
 268
 269 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 270 {
 271         struct device_driver *drv = phydev->dev.driver;
 272         struct phy_driver *phydrv = to_phy_driver(drv);
 273         struct net_device *netdev = phydev->attached_dev;
 274
 275         if (!drv || !phydrv->suspend)
 276                 return false;
 277
 278         /* PHY not attached? May suspend. */
 279         if (!netdev)
 280                 return true;
 281
 282         /*
 283          * Don't suspend PHY if the attched netdev parent may wakeup.
 284          * The parent may point to a PCI device, as in tg3 driver.
 285          */
 286         if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
 287                 return false;
 288
 289         /*
 290          * Also don't suspend PHY if the netdev itself may wakeup. This
 291          * is the case for devices w/o underlaying pwr. mgmt. aware bus,
 292          * e.g. SoC devices.
 293          */
 294         if (device_may_wakeup(&netdev->dev))
 295                 return false;
 296
 297         return true;
 298 }
 299
 300 static int mdio_bus_suspend(struct device *dev)
 301 {
 302         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 303         struct phy_device *phydev = to_phy_device(dev);
 304
 305         /*
 306          * We must stop the state machine manually, otherwise it stops out of
 307          * control, possibly with the phydev->lock held. Upon resume, netdev
 308          * may call phy routines that try to grab the same lock, and that may
 309          * lead to a deadlock.
 310          */
 311         if (phydev->attached_dev && phydev->adjust_link)
 312                 phy_stop_machine(phydev);
 313
 314         if (!mdio_bus_phy_may_suspend(phydev))
 315                 return 0;
 316
 317         return phydrv->suspend(phydev);
 318 }
 319
 320 static int mdio_bus_resume(struct device *dev)
 321 {
 322         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 323         struct phy_device *phydev = to_phy_device(dev);
 324         int ret;
 325
 326         if (!mdio_bus_phy_may_suspend(phydev))
 327                 goto no_resume;
 328
 329         ret = phydrv->resume(phydev);
 330         if (ret < 0)
 331                 return ret;
 332
 333 no_resume:
 334         if (phydev->attached_dev && phydev->adjust_link)
 335                 phy_start_machine(phydev, NULL);
 336
 337         return 0;
 338 }
 339
 340 static int mdio_bus_restore(struct device *dev)
 341 {
 342         struct phy_device *phydev = to_phy_device(dev);
 343         struct net_device *netdev = phydev->attached_dev;
 344         int ret;
 345
 346         if (!netdev)
 347                 return 0;
 348
 349         ret = phy_init_hw(phydev);
 350         if (ret < 0)
 351                 return ret;
 352
 353         /* The PHY needs to renegotiate. */
 354         phydev->link = 0;
 355         phydev->state = PHY_UP;
 356
 357         phy_start_machine(phydev, NULL);
 358
 359         return 0;
 360 }
 361
 362 static struct dev_pm_ops mdio_bus_pm_ops = {
 363         .suspend = mdio_bus_suspend,
 364         .resume = mdio_bus_resume,
 365         .freeze = mdio_bus_suspend,
 366         .thaw = mdio_bus_resume,
 367         .restore = mdio_bus_restore,
 368 };
 369
 370 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
 371
 372 #else
 373
 374 #define MDIO_BUS_PM_OPS NULL
 375
 376 #endif /* CONFIG_PM */
 377
 378 struct bus_type mdio_bus_type = {
 379         .name           = "mdio_bus",
 380         .match          = mdio_bus_match,
 381         .pm             = MDIO_BUS_PM_OPS,
 382 };
 383 EXPORT_SYMBOL(mdio_bus_type);
 384
 385 int __init mdio_bus_init(void)
 386 {
 387         int ret;
 388
 389         ret = class_register(&mdio_bus_class);
 390         if (!ret) {
 391                 ret = bus_register(&mdio_bus_type);
 392                 if (ret)
 393                         class_unregister(&mdio_bus_class);
 394         }
 395
 396         return ret;
 397 }
 398
 399 void mdio_bus_exit(void)
 400 {
 401         class_unregister(&mdio_bus_class);
 402         bus_unregister(&mdio_bus_type);
 403 }