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, u16 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, u16 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 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 268 {
 269         struct device_driver *drv = phydev->dev.driver;
 270         struct phy_driver *phydrv = to_phy_driver(drv);
 271         struct net_device *netdev = phydev->attached_dev;
 272
 273         if (!drv || !phydrv->suspend)
 274                 return false;
 275
 276         /* PHY not attached? May suspend. */
 277         if (!netdev)
 278                 return true;
 279
 280         /*
 281          * Don't suspend PHY if the attched netdev parent may wakeup.
 282          * The parent may point to a PCI device, as in tg3 driver.
 283          */
 284         if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
 285                 return false;
 286
 287         /*
 288          * Also don't suspend PHY if the netdev itself may wakeup. This
 289          * is the case for devices w/o underlaying pwr. mgmt. aware bus,
 290          * e.g. SoC devices.
 291          */
 292         if (device_may_wakeup(&netdev->dev))
 293                 return false;
 294
 295         return true;
 296 }
 297
 298 /* Suspend and resume.  Copied from platform_suspend and
 299  * platform_resume
 300  */
 301 static int mdio_bus_suspend(struct device * dev, pm_message_t state)
 302 {
 303         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 304         struct phy_device *phydev = to_phy_device(dev);
 305
 306         if (!mdio_bus_phy_may_suspend(phydev))
 307                 return 0;
 308         return phydrv->suspend(phydev);
 309 }
 310
 311 static int mdio_bus_resume(struct device * dev)
 312 {
 313         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 314         struct phy_device *phydev = to_phy_device(dev);
 315
 316         if (!mdio_bus_phy_may_suspend(phydev))
 317                 return 0;
 318         return phydrv->resume(phydev);
 319 }
 320
 321 struct bus_type mdio_bus_type = {
 322         .name           = "mdio_bus",
 323         .match          = mdio_bus_match,
 324         .suspend        = mdio_bus_suspend,
 325         .resume         = mdio_bus_resume,
 326 };
 327 EXPORT_SYMBOL(mdio_bus_type);
 328
 329 int __init mdio_bus_init(void)
 330 {
 331         int ret;
 332
 333         ret = class_register(&mdio_bus_class);
 334         if (!ret) {
 335                 ret = bus_register(&mdio_bus_type);
 336                 if (ret)
 337                         class_unregister(&mdio_bus_class);
 338         }
 339
 340         return ret;
 341 }
 342
 343 void mdio_bus_exit(void)
 344 {
 345         class_unregister(&mdio_bus_class);
 346         bus_unregister(&mdio_bus_type);
 347 }