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, 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                 bus->phy_map[i] = NULL;
 117                 if ((bus->phy_mask & (1 << i)) == 0) {
 118                         struct phy_device *phydev;
 119
 120                         phydev = mdiobus_scan(bus, i);
 121                         if (IS_ERR(phydev)) {
 122                                 err = PTR_ERR(phydev);
 123                                 goto error;
 124                         }
 125                 }
 126         }
 127
 128         bus->state = MDIOBUS_REGISTERED;
 129         pr_info("%s: probed\n", bus->name);
 130         return 0;
 131
 132 error:
 133         while (--i >= 0) {
 134                 if (bus->phy_map[i])
 135                         device_unregister(&bus->phy_map[i]->dev);
 136         }
 137         device_del(&bus->dev);
 138         return err;
 139 }
 140 EXPORT_SYMBOL(mdiobus_register);
 141
 142 void mdiobus_unregister(struct mii_bus *bus)
 143 {
 144         int i;
 145
 146         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 147         bus->state = MDIOBUS_UNREGISTERED;
 148
 149         device_del(&bus->dev);
 150         for (i = 0; i < PHY_MAX_ADDR; i++) {
 151                 if (bus->phy_map[i])
 152                         device_unregister(&bus->phy_map[i]->dev);
 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         /* There's a PHY at this address
 192          * We need to set:
 193          * 1) IRQ
 194          * 2) bus_id
 195          * 3) parent
 196          * 4) bus
 197          * 5) mii_bus
 198          * And, we need to register it */
 199
 200         phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
 201
 202         phydev->dev.parent = bus->parent;
 203         phydev->dev.bus = &mdio_bus_type;
 204         dev_set_name(&phydev->dev, PHY_ID_FMT, bus->id, addr);
 205
 206         phydev->bus = bus;
 207
 208         /* Run all of the fixups for this PHY */
 209         phy_scan_fixups(phydev);
 210
 211         err = device_register(&phydev->dev);
 212         if (err) {
 213                 printk(KERN_ERR "phy %d failed to register\n", addr);
 214                 phy_device_free(phydev);
 215                 phydev = NULL;
 216         }
 217
 218         bus->phy_map[addr] = phydev;
 219
 220         return phydev;
 221 }
 222 EXPORT_SYMBOL(mdiobus_scan);
 223
 224 /**
 225  * mdiobus_read - Convenience function for reading a given MII mgmt register
 226  * @bus: the mii_bus struct
 227  * @addr: the phy address
 228  * @regnum: register number to read
 229  *
 230  * NOTE: MUST NOT be called from interrupt context,
 231  * because the bus read/write functions may wait for an interrupt
 232  * to conclude the operation.
 233  */
 234 int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum)
 235 {
 236         int retval;
 237
 238         BUG_ON(in_interrupt());
 239
 240         mutex_lock(&bus->mdio_lock);
 241         retval = bus->read(bus, addr, regnum);
 242         mutex_unlock(&bus->mdio_lock);
 243
 244         return retval;
 245 }
 246 EXPORT_SYMBOL(mdiobus_read);
 247
 248 /**
 249  * mdiobus_write - Convenience function for writing a given MII mgmt register
 250  * @bus: the mii_bus struct
 251  * @addr: the phy address
 252  * @regnum: register number to write
 253  * @val: value to write to @regnum
 254  *
 255  * NOTE: MUST NOT be called from interrupt context,
 256  * because the bus read/write functions may wait for an interrupt
 257  * to conclude the operation.
 258  */
 259 int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val)
 260 {
 261         int err;
 262
 263         BUG_ON(in_interrupt());
 264
 265         mutex_lock(&bus->mdio_lock);
 266         err = bus->write(bus, addr, regnum, val);
 267         mutex_unlock(&bus->mdio_lock);
 268
 269         return err;
 270 }
 271 EXPORT_SYMBOL(mdiobus_write);
 272
 273 /**
 274  * mdio_bus_match - determine if given PHY driver supports the given PHY device
 275  * @dev: target PHY device
 276  * @drv: given PHY driver
 277  *
 278  * Description: Given a PHY device, and a PHY driver, return 1 if
 279  *   the driver supports the device.  Otherwise, return 0.
 280  */
 281 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 282 {
 283         struct phy_device *phydev = to_phy_device(dev);
 284         struct phy_driver *phydrv = to_phy_driver(drv);
 285
 286         return ((phydrv->phy_id & phydrv->phy_id_mask) ==
 287                 (phydev->phy_id & phydrv->phy_id_mask));
 288 }
 289
 290 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 291 {
 292         struct device_driver *drv = phydev->dev.driver;
 293         struct phy_driver *phydrv = to_phy_driver(drv);
 294         struct net_device *netdev = phydev->attached_dev;
 295
 296         if (!drv || !phydrv->suspend)
 297                 return false;
 298
 299         /* PHY not attached? May suspend. */
 300         if (!netdev)
 301                 return true;
 302
 303         /*
 304          * Don't suspend PHY if the attched netdev parent may wakeup.
 305          * The parent may point to a PCI device, as in tg3 driver.
 306          */
 307         if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
 308                 return false;
 309
 310         /*
 311          * Also don't suspend PHY if the netdev itself may wakeup. This
 312          * is the case for devices w/o underlaying pwr. mgmt. aware bus,
 313          * e.g. SoC devices.
 314          */
 315         if (device_may_wakeup(&netdev->dev))
 316                 return false;
 317
 318         return true;
 319 }
 320
 321 /* Suspend and resume.  Copied from platform_suspend and
 322  * platform_resume
 323  */
 324 static int mdio_bus_suspend(struct device * dev, pm_message_t state)
 325 {
 326         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 327         struct phy_device *phydev = to_phy_device(dev);
 328
 329         if (!mdio_bus_phy_may_suspend(phydev))
 330                 return 0;
 331         return phydrv->suspend(phydev);
 332 }
 333
 334 static int mdio_bus_resume(struct device * dev)
 335 {
 336         struct phy_driver *phydrv = to_phy_driver(dev->driver);
 337         struct phy_device *phydev = to_phy_device(dev);
 338
 339         if (!mdio_bus_phy_may_suspend(phydev))
 340                 return 0;
 341         return phydrv->resume(phydev);
 342 }
 343
 344 struct bus_type mdio_bus_type = {
 345         .name           = "mdio_bus",
 346         .match          = mdio_bus_match,
 347         .suspend        = mdio_bus_suspend,
 348         .resume         = mdio_bus_resume,
 349 };
 350 EXPORT_SYMBOL(mdio_bus_type);
 351
 352 int __init mdio_bus_init(void)
 353 {
 354         int ret;
 355
 356         ret = class_register(&mdio_bus_class);
 357         if (!ret) {
 358                 ret = bus_register(&mdio_bus_type);
 359                 if (ret)
 360                         class_unregister(&mdio_bus_class);
 361         }
 362
 363         return ret;
 364 }
 365
 366 void mdio_bus_exit(void)
 367 {
 368         class_unregister(&mdio_bus_class);
 369         bus_unregister(&mdio_bus_type);
 370 }