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         kfree(bus);
  68 }
  69
  70 static struct class mdio_bus_class = {
  71         .name           = "mdio_bus",
  72         .dev_release    = mdiobus_release,
  73 };
  74
  75 /**
  76  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  77  * @bus: target mii_bus
  78  *
  79  * Description: Called by a bus driver to bring up all the PHYs
  80  *   on a given bus, and attach them to the bus.
  81  *
  82  * Returns 0 on success or < 0 on error.
  83  */
  84 int mdiobus_register(struct mii_bus *bus)
  85 {
  86         int i;
  87         int err = 0;
  88
  89         if (NULL == bus || NULL == bus->name ||
  90                         NULL == bus->read ||
  91                         NULL == bus->write)
  92                 return -EINVAL;
  93
  94         BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
  95                bus->state != MDIOBUS_UNREGISTERED);
  96
  97         bus->dev.parent = bus->parent;
  98         bus->dev.class = &mdio_bus_class;
  99         bus->dev.groups = NULL;
 100         memcpy(bus->dev.bus_id, bus->id, MII_BUS_ID_SIZE);
 101
 102         err = device_register(&bus->dev);
 103         if (err) {
 104                 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
 105                 return -EINVAL;
 106         }
 107
 108         mutex_init(&bus->mdio_lock);
 109
 110         if (bus->reset)
 111                 bus->reset(bus);
 112
 113         for (i = 0; i < PHY_MAX_ADDR; i++) {
 114                 bus->phy_map[i] = NULL;
 115                 if ((bus->phy_mask & (1 << i)) == 0) {
 116                         struct phy_device *phydev;
 117
 118                         phydev = mdiobus_scan(bus, i);
 119                         if (IS_ERR(phydev))
 120                                 err = PTR_ERR(phydev);
 121                 }
 122         }
 123
 124         if (!err)
 125                 bus->state = MDIOBUS_REGISTERED;
 126
 127         pr_info("%s: probed\n", bus->name);
 128
 129         return err;
 130 }
 131 EXPORT_SYMBOL(mdiobus_register);
 132
 133 void mdiobus_unregister(struct mii_bus *bus)
 134 {
 135         int i;
 136
 137         BUG_ON(bus->state != MDIOBUS_REGISTERED);
 138         bus->state = MDIOBUS_UNREGISTERED;
 139
 140         device_del(&bus->dev);
 141         for (i = 0; i < PHY_MAX_ADDR; i++) {
 142                 if (bus->phy_map[i])
 143                         device_unregister(&bus->phy_map[i]->dev);
 144         }
 145 }
 146 EXPORT_SYMBOL(mdiobus_unregister);
 147
 148 /**
 149  * mdiobus_free - free a struct mii_bus
 150  * @bus: mii_bus to free
 151  *
 152  * This function releases the reference to the underlying device
 153  * object in the mii_bus.  If this is the last reference, the mii_bus
 154  * will be freed.
 155  */
 156 void mdiobus_free(struct mii_bus *bus)
 157 {
 158         /*
 159          * For compatibility with error handling in drivers.
 160          */
 161         if (bus->state == MDIOBUS_ALLOCATED) {
 162                 kfree(bus);
 163                 return;
 164         }
 165
 166         BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 167         bus->state = MDIOBUS_RELEASED;
 168
 169         put_device(&bus->dev);
 170 }
 171 EXPORT_SYMBOL(mdiobus_free);
 172
 173 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 174 {
 175         struct phy_device *phydev;
 176         int err;
 177
 178         phydev = get_phy_device(bus, addr);
 179         if (IS_ERR(phydev) || phydev == NULL)
 180                 return phydev;
 181
 182         /* There's a PHY at this address
 183          * We need to set:
 184          * 1) IRQ
 185          * 2) bus_id
 186          * 3) parent
 187          * 4) bus
 188          * 5) mii_bus
 189          * And, we need to register it */
 190
 191         phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
 192
 193         phydev->dev.parent = bus->parent;
 194         phydev->dev.bus = &mdio_bus_type;
 195         snprintf(phydev->dev.bus_id, BUS_ID_SIZE, PHY_ID_FMT, bus->id, addr);
 196
 197         phydev->bus = bus;
 198
 199         /* Run all of the fixups for this PHY */
 200         phy_scan_fixups(phydev);
 201
 202         err = device_register(&phydev->dev);
 203         if (err) {
 204                 printk(KERN_ERR "phy %d failed to register\n", addr);
 205                 phy_device_free(phydev);
 206                 phydev = NULL;
 207         }
 208
 209         bus->phy_map[addr] = phydev;
 210
 211         return phydev;
 212 }
 213 EXPORT_SYMBOL(mdiobus_scan);
 214
 215 /**
 216  * mdiobus_read - Convenience function for reading a given MII mgmt register
 217  * @bus: the mii_bus struct
 218  * @addr: the phy address
 219  * @regnum: register number to read
 220  *
 221  * NOTE: MUST NOT be called from interrupt context,
 222  * because the bus read/write functions may wait for an interrupt
 223  * to conclude the operation.
 224  */
 225 int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum)
 226 {
 227         int retval;
 228
 229         BUG_ON(in_interrupt());
 230
 231         mutex_lock(&bus->mdio_lock);
 232         retval = bus->read(bus, addr, regnum);
 233         mutex_unlock(&bus->mdio_lock);
 234
 235         return retval;
 236 }
 237 EXPORT_SYMBOL(mdiobus_read);
 238
 239 /**
 240  * mdiobus_write - Convenience function for writing a given MII mgmt register
 241  * @bus: the mii_bus struct
 242  * @addr: the phy address
 243  * @regnum: register number to write
 244  * @val: value to write to @regnum
 245  *
 246  * NOTE: MUST NOT be called from interrupt context,
 247  * because the bus read/write functions may wait for an interrupt
 248  * to conclude the operation.
 249  */
 250 int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val)
 251 {
 252         int err;
 253
 254         BUG_ON(in_interrupt());
 255
 256         mutex_lock(&bus->mdio_lock);
 257         err = bus->write(bus, addr, regnum, val);
 258         mutex_unlock(&bus->mdio_lock);
 259
 260         return err;
 261 }
 262 EXPORT_SYMBOL(mdiobus_write);
 263
 264 /**
 265  * mdio_bus_match - determine if given PHY driver supports the given PHY device
 266  * @dev: target PHY device
 267  * @drv: given PHY driver
 268  *
 269  * Description: Given a PHY device, and a PHY driver, return 1 if
 270  *   the driver supports the device.  Otherwise, return 0.
 271  */
 272 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 273 {
 274         struct phy_device *phydev = to_phy_device(dev);
 275         struct phy_driver *phydrv = to_phy_driver(drv);
 276
 277         return ((phydrv->phy_id & phydrv->phy_id_mask) ==
 278                 (phydev->phy_id & phydrv->phy_id_mask));
 279 }
 280
 281 /* Suspend and resume.  Copied from platform_suspend and
 282  * platform_resume
 283  */
 284 static int mdio_bus_suspend(struct device * dev, pm_message_t state)
 285 {
 286         int ret = 0;
 287         struct device_driver *drv = dev->driver;
 288
 289         if (drv && drv->suspend)
 290                 ret = drv->suspend(dev, state);
 291
 292         return ret;
 293 }
 294
 295 static int mdio_bus_resume(struct device * dev)
 296 {
 297         int ret = 0;
 298         struct device_driver *drv = dev->driver;
 299
 300         if (drv && drv->resume)
 301                 ret = drv->resume(dev);
 302
 303         return ret;
 304 }
 305
 306 struct bus_type mdio_bus_type = {
 307         .name           = "mdio_bus",
 308         .match          = mdio_bus_match,
 309         .suspend        = mdio_bus_suspend,
 310         .resume         = mdio_bus_resume,
 311 };
 312 EXPORT_SYMBOL(mdio_bus_type);
 313
 314 int __init mdio_bus_init(void)
 315 {
 316         int ret;
 317
 318         ret = class_register(&mdio_bus_class);
 319         if (!ret) {
 320                 ret = bus_register(&mdio_bus_type);
 321                 if (ret)
 322                         class_unregister(&mdio_bus_class);
 323         }
 324
 325         return ret;
 326 }
 327
 328 void mdio_bus_exit(void)
 329 {
 330         class_unregister(&mdio_bus_class);
 331         bus_unregister(&mdio_bus_type);
 332 }