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/netdevice.h>
  25 #include <linux/etherdevice.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/mm.h>
  29 #include <linux/module.h>
  30 #include <linux/mii.h>
  31 #include <linux/ethtool.h>
  32 #include <linux/phy.h>
  33
  34 #include <asm/io.h>
  35 #include <asm/irq.h>
  36 #include <asm/uaccess.h>
  37
  38 /**
  39  * mdiobus_alloc - allocate a mii_bus structure
  40  *
  41  * Description: called by a bus driver to allocate an mii_bus
  42  * structure to fill in.
  43  */
  44 struct mii_bus *mdiobus_alloc(void)
  45 {
  46         struct mii_bus *bus;
  47
  48         bus = kzalloc(sizeof(*bus), GFP_KERNEL);
  49         if (bus != NULL)
  50                 bus->state = MDIOBUS_ALLOCATED;
  51
  52         return bus;
  53 }
  54 EXPORT_SYMBOL(mdiobus_alloc);
  55
  56 /**
  57  * mdiobus_release - mii_bus device release callback
  58  * @d: the target struct device that contains the mii_bus
  59  *
  60  * Description: called when the last reference to an mii_bus is
  61  * dropped, to free the underlying memory.
  62  */
  63 static void mdiobus_release(struct device *d)
  64 {
  65         struct mii_bus *bus = to_mii_bus(d);
  66         BUG_ON(bus->state != MDIOBUS_RELEASED &&
  67                /* for compatibility with error handling in drivers */
  68                bus->state != MDIOBUS_ALLOCATED);
  69         kfree(bus);
  70 }
  71
  72 static struct class mdio_bus_class = {
  73         .name           = "mdio_bus",
  74         .dev_release    = mdiobus_release,
  75 };
  76
  77 /**
  78  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  79  * @bus: target mii_bus
  80  *
  81  * Description: Called by a bus driver to bring up all the PHYs
  82  *   on a given bus, and attach them to the bus.
  83  *
  84  * Returns 0 on success or < 0 on error.
  85  */
  86 int mdiobus_register(struct mii_bus *bus)
  87 {
  88         int i, err;
  89
  90         if (NULL == bus || NULL == bus->name ||
  91                         NULL == bus->read ||
  92                         NULL == bus->write)
  93                 return -EINVAL;
  94
  95         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
  96                bus->state != MDIOBUS_UNREGISTERED);
  97
  98         bus->dev.parent = bus->parent;
  99         bus->dev.class = &mdio_bus_class;
 100         bus->dev.groups = NULL;
 101         dev_set_name(&bus->dev, bus->id);
 102
 103         err = device_register(&bus->dev);
 104         if (err) {
 105                 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
 106                 return -EINVAL;
 107         }
 108
 109         mutex_init(&bus->mdio_lock);
 110
 111         if (bus->reset)
 112                 bus->reset(bus);
 113
 114         for (i = 0; i < PHY_MAX_ADDR; i++) {
 115                 bus->phy_map[i] = NULL;
 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         }
 153 }
 154 EXPORT_SYMBOL(mdiobus_unregister);
 155
 156 /**
 157  * mdiobus_free - free a struct mii_bus
 158  * @bus: mii_bus to free
 159  *
 160  * This function releases the reference to the underlying device
 161  * object in the mii_bus.  If this is the last reference, the mii_bus
 162  * will be freed.
 163  */
 164 void mdiobus_free(struct mii_bus *bus)
 165 {
 166         /*
 167          * For compatibility with error handling in drivers.
 168          */
 169         if (bus->state == MDIOBUS_ALLOCATED) {
 170                 kfree(bus);
 171                 return;
 172         }
 173
 174         BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 175         bus->state = MDIOBUS_RELEASED;
 176
 177         put_device(&bus->dev);
 178 }
 179 EXPORT_SYMBOL(mdiobus_free);
 180
 181 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 182 {
 183         struct phy_device *phydev;
 184         int err;
 185
 186         phydev = get_phy_device(bus, addr);
 187         if (IS_ERR(phydev) || phydev == NULL)
 188                 return phydev;
 189
 190         /* There's a PHY at this address
 191          * We need to set:
 192          * 1) IRQ
 193          * 2) bus_id
 194          * 3) parent
 195          * 4) bus
 196          * 5) mii_bus
 197          * And, we need to register it */
 198
 199         phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
 200
 201         phydev->dev.parent = bus->parent;
 202         phydev->dev.bus = &mdio_bus_type;
 203         dev_set_name(&phydev->dev, PHY_ID_FMT, bus->id, addr);
 204
 205         phydev->bus = bus;
 206
 207         /* Run all of the fixups for this PHY */
 208         phy_scan_fixups(phydev);
 209
 210         err = device_register(&phydev->dev);
 211         if (err) {
 212                 printk(KERN_ERR "phy %d failed to register\n", addr);
 213                 phy_device_free(phydev);
 214                 phydev = NULL;
 215         }
 216
 217         bus->phy_map[addr] = phydev;
 218
 219         return phydev;
 220 }
 221 EXPORT_SYMBOL(mdiobus_scan);
 222
 223 /**
 224  * mdiobus_read - Convenience function for reading a given MII mgmt register
 225  * @bus: the mii_bus struct
 226  * @addr: the phy address
 227  * @regnum: register number to read
 228  *
 229  * NOTE: MUST NOT be called from interrupt context,
 230  * because the bus read/write functions may wait for an interrupt
 231  * to conclude the operation.
 232  */
 233 int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum)
 234 {
 235         int retval;
 236
 237         BUG_ON(in_interrupt());
 238
 239         mutex_lock(&bus->mdio_lock);
 240         retval = bus->read(bus, addr, regnum);
 241         mutex_unlock(&bus->mdio_lock);
 242
 243         return retval;
 244 }
 245 EXPORT_SYMBOL(mdiobus_read);
 246
 247 /**
 248  * mdiobus_write - Convenience function for writing a given MII mgmt register
 249  * @bus: the mii_bus struct
 250  * @addr: the phy address
 251  * @regnum: register number to write
 252  * @val: value to write to @regnum
 253  *
 254  * NOTE: MUST NOT be called from interrupt context,
 255  * because the bus read/write functions may wait for an interrupt
 256  * to conclude the operation.
 257  */
 258 int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val)
 259 {
 260         int err;
 261
 262         BUG_ON(in_interrupt());
 263
 264         mutex_lock(&bus->mdio_lock);
 265         err = bus->write(bus, addr, regnum, val);
 266         mutex_unlock(&bus->mdio_lock);
 267
 268         return err;
 269 }
 270 EXPORT_SYMBOL(mdiobus_write);
 271
 272 /**
 273  * mdio_bus_match - determine if given PHY driver supports the given PHY device
 274  * @dev: target PHY device
 275  * @drv: given PHY driver
 276  *
 277  * Description: Given a PHY device, and a PHY driver, return 1 if
 278  *   the driver supports the device.  Otherwise, return 0.
 279  */
 280 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 281 {
 282         struct phy_device *phydev = to_phy_device(dev);
 283         struct phy_driver *phydrv = to_phy_driver(drv);
 284
 285         return ((phydrv->phy_id & phydrv->phy_id_mask) ==
 286                 (phydev->phy_id & phydrv->phy_id_mask));
 287 }
 288
 289 /* Suspend and resume.  Copied from platform_suspend and
 290  * platform_resume
 291  */
 292 static int mdio_bus_suspend(struct device * dev, pm_message_t state)
 293 {
 294         int ret = 0;
 295         struct device_driver *drv = dev->driver;
 296         struct phy_driver *phydrv = to_phy_driver(drv);
 297         struct phy_device *phydev = to_phy_device(dev);
 298
 299         if (drv && phydrv->suspend && !device_may_wakeup(phydev->dev.parent))
 300                 ret = phydrv->suspend(phydev);
 301
 302         return ret;
 303 }
 304
 305 static int mdio_bus_resume(struct device * dev)
 306 {
 307         int ret = 0;
 308         struct device_driver *drv = dev->driver;
 309         struct phy_driver *phydrv = to_phy_driver(drv);
 310         struct phy_device *phydev = to_phy_device(dev);
 311
 312         if (drv && phydrv->resume && !device_may_wakeup(phydev->dev.parent))
 313                 ret = phydrv->resume(phydev);
 314
 315         return ret;
 316 }
 317
 318 struct bus_type mdio_bus_type = {
 319         .name           = "mdio_bus",
 320         .match          = mdio_bus_match,
 321         .suspend        = mdio_bus_suspend,
 322         .resume         = mdio_bus_resume,
 323 };
 324 EXPORT_SYMBOL(mdio_bus_type);
 325
 326 int __init mdio_bus_init(void)
 327 {
 328         int ret;
 329
 330         ret = class_register(&mdio_bus_class);
 331         if (!ret) {
 332                 ret = bus_register(&mdio_bus_type);
 333                 if (ret)
 334                         class_unregister(&mdio_bus_class);
 335         }
 336
 337         return ret;
 338 }
 339
 340 void mdio_bus_exit(void)
 341 {
 342         class_unregister(&mdio_bus_class);
 343         bus_unregister(&mdio_bus_type);
 344 }