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 } 404