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_size - allocate a mii_bus structure 41 * @size: extra amount of memory to allocate for private storage. 42 * If non-zero, then bus->priv is points to that memory. 43 * 44 * Description: called by a bus driver to allocate an mii_bus 45 * structure to fill in. 46 */ 47 struct mii_bus *mdiobus_alloc_size(size_t size) 48 { 49 struct mii_bus *bus; 50 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN); 51 size_t alloc_size; 52 53 /* If we alloc extra space, it should be aligned */ 54 if (size) 55 alloc_size = aligned_size + size; 56 else 57 alloc_size = sizeof(*bus); 58 59 bus = kzalloc(alloc_size, GFP_KERNEL); 60 if (bus) { 61 bus->state = MDIOBUS_ALLOCATED; 62 if (size) 63 bus->priv = (void *)bus + aligned_size; 64 } 65 66 return bus; 67 } 68 EXPORT_SYMBOL(mdiobus_alloc_size); 69 70 /** 71 * mdiobus_release - mii_bus device release callback 72 * @d: the target struct device that contains the mii_bus 73 * 74 * Description: called when the last reference to an mii_bus is 75 * dropped, to free the underlying memory. 76 */ 77 static void mdiobus_release(struct device *d) 78 { 79 struct mii_bus *bus = to_mii_bus(d); 80 BUG_ON(bus->state != MDIOBUS_RELEASED && 81 /* for compatibility with error handling in drivers */ 82 bus->state != MDIOBUS_ALLOCATED); 83 kfree(bus); 84 } 85 86 static struct class mdio_bus_class = { 87 .name = "mdio_bus", 88 .dev_release = mdiobus_release, 89 }; 90 91 #if IS_ENABLED(CONFIG_OF_MDIO) 92 /* Helper function for of_mdio_find_bus */ 93 static int of_mdio_bus_match(struct device *dev, void *mdio_bus_np) 94 { 95 return dev->of_node == mdio_bus_np; 96 } 97 /** 98 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus. 99 * @mdio_bus_np: Pointer to the mii_bus. 100 * 101 * Returns a pointer to the mii_bus, or NULL if none found. 102 * 103 * Because the association of a device_node and mii_bus is made via 104 * of_mdiobus_register(), the mii_bus cannot be found before it is 105 * registered with of_mdiobus_register(). 106 * 107 */ 108 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np) 109 { 110 struct device *d; 111 112 if (!mdio_bus_np) 113 return NULL; 114 115 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np, 116 of_mdio_bus_match); 117 118 return d ? to_mii_bus(d) : NULL; 119 } 120 EXPORT_SYMBOL(of_mdio_find_bus); 121 #endif 122 123 /** 124 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus 125 * @bus: target mii_bus 126 * 127 * Description: Called by a bus driver to bring up all the PHYs 128 * on a given bus, and attach them to the bus. 129 * 130 * Returns 0 on success or < 0 on error. 131 */ 132 int mdiobus_register(struct mii_bus *bus) 133 { 134 int i, err; 135 136 if (NULL == bus || NULL == bus->name || 137 NULL == bus->read || 138 NULL == bus->write) 139 return -EINVAL; 140 141 BUG_ON(bus->state != MDIOBUS_ALLOCATED && 142 bus->state != MDIOBUS_UNREGISTERED); 143 144 bus->dev.parent = bus->parent; 145 bus->dev.class = &mdio_bus_class; 146 bus->dev.groups = NULL; 147 dev_set_name(&bus->dev, "%s", bus->id); 148 149 err = device_register(&bus->dev); 150 if (err) { 151 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id); 152 return -EINVAL; 153 } 154 155 mutex_init(&bus->mdio_lock); 156 157 if (bus->reset) 158 bus->reset(bus); 159 160 for (i = 0; i < PHY_MAX_ADDR; i++) { 161 if ((bus->phy_mask & (1 << i)) == 0) { 162 struct phy_device *phydev; 163 164 phydev = mdiobus_scan(bus, i); 165 if (IS_ERR(phydev)) { 166 err = PTR_ERR(phydev); 167 goto error; 168 } 169 } 170 } 171 172 bus->state = MDIOBUS_REGISTERED; 173 pr_info("%s: probed\n", bus->name); 174 return 0; 175 176 error: 177 while (--i >= 0) { 178 if (bus->phy_map[i]) 179 device_unregister(&bus->phy_map[i]->dev); 180 } 181 device_del(&bus->dev); 182 return err; 183 } 184 EXPORT_SYMBOL(mdiobus_register); 185 186 void mdiobus_unregister(struct mii_bus *bus) 187 { 188 int i; 189 190 BUG_ON(bus->state != MDIOBUS_REGISTERED); 191 bus->state = MDIOBUS_UNREGISTERED; 192 193 device_del(&bus->dev); 194 for (i = 0; i < PHY_MAX_ADDR; i++) { 195 if (bus->phy_map[i]) 196 device_unregister(&bus->phy_map[i]->dev); 197 bus->phy_map[i] = NULL; 198 } 199 } 200 EXPORT_SYMBOL(mdiobus_unregister); 201 202 /** 203 * mdiobus_free - free a struct mii_bus 204 * @bus: mii_bus to free 205 * 206 * This function releases the reference to the underlying device 207 * object in the mii_bus. If this is the last reference, the mii_bus 208 * will be freed. 209 */ 210 void mdiobus_free(struct mii_bus *bus) 211 { 212 /* 213 * For compatibility with error handling in drivers. 214 */ 215 if (bus->state == MDIOBUS_ALLOCATED) { 216 kfree(bus); 217 return; 218 } 219 220 BUG_ON(bus->state != MDIOBUS_UNREGISTERED); 221 bus->state = MDIOBUS_RELEASED; 222 223 put_device(&bus->dev); 224 } 225 EXPORT_SYMBOL(mdiobus_free); 226 227 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) 228 { 229 struct phy_device *phydev; 230 int err; 231 232 phydev = get_phy_device(bus, addr); 233 if (IS_ERR(phydev) || phydev == NULL) 234 return phydev; 235 236 err = phy_device_register(phydev); 237 if (err) { 238 phy_device_free(phydev); 239 return NULL; 240 } 241 242 return phydev; 243 } 244 EXPORT_SYMBOL(mdiobus_scan); 245 246 /** 247 * mdiobus_read - Convenience function for reading a given MII mgmt register 248 * @bus: the mii_bus struct 249 * @addr: the phy address 250 * @regnum: register number to read 251 * 252 * NOTE: MUST NOT be called from interrupt context, 253 * because the bus read/write functions may wait for an interrupt 254 * to conclude the operation. 255 */ 256 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) 257 { 258 int retval; 259 260 BUG_ON(in_interrupt()); 261 262 mutex_lock(&bus->mdio_lock); 263 retval = bus->read(bus, addr, regnum); 264 mutex_unlock(&bus->mdio_lock); 265 266 return retval; 267 } 268 EXPORT_SYMBOL(mdiobus_read); 269 270 /** 271 * mdiobus_write - Convenience function for writing a given MII mgmt register 272 * @bus: the mii_bus struct 273 * @addr: the phy address 274 * @regnum: register number to write 275 * @val: value to write to @regnum 276 * 277 * NOTE: MUST NOT be called from interrupt context, 278 * because the bus read/write functions may wait for an interrupt 279 * to conclude the operation. 280 */ 281 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) 282 { 283 int err; 284 285 BUG_ON(in_interrupt()); 286 287 mutex_lock(&bus->mdio_lock); 288 err = bus->write(bus, addr, regnum, val); 289 mutex_unlock(&bus->mdio_lock); 290 291 return err; 292 } 293 EXPORT_SYMBOL(mdiobus_write); 294 295 /** 296 * mdio_bus_match - determine if given PHY driver supports the given PHY device 297 * @dev: target PHY device 298 * @drv: given PHY driver 299 * 300 * Description: Given a PHY device, and a PHY driver, return 1 if 301 * the driver supports the device. Otherwise, return 0. 302 */ 303 static int mdio_bus_match(struct device *dev, struct device_driver *drv) 304 { 305 struct phy_device *phydev = to_phy_device(dev); 306 struct phy_driver *phydrv = to_phy_driver(drv); 307 308 return ((phydrv->phy_id & phydrv->phy_id_mask) == 309 (phydev->phy_id & phydrv->phy_id_mask)); 310 } 311 312 #ifdef CONFIG_PM 313 314 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev) 315 { 316 struct device_driver *drv = phydev->dev.driver; 317 struct phy_driver *phydrv = to_phy_driver(drv); 318 struct net_device *netdev = phydev->attached_dev; 319 320 if (!drv || !phydrv->suspend) 321 return false; 322 323 /* PHY not attached? May suspend. */ 324 if (!netdev) 325 return true; 326 327 /* 328 * Don't suspend PHY if the attched netdev parent may wakeup. 329 * The parent may point to a PCI device, as in tg3 driver. 330 */ 331 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent)) 332 return false; 333 334 /* 335 * Also don't suspend PHY if the netdev itself may wakeup. This 336 * is the case for devices w/o underlaying pwr. mgmt. aware bus, 337 * e.g. SoC devices. 338 */ 339 if (device_may_wakeup(&netdev->dev)) 340 return false; 341 342 return true; 343 } 344 345 static int mdio_bus_suspend(struct device *dev) 346 { 347 struct phy_driver *phydrv = to_phy_driver(dev->driver); 348 struct phy_device *phydev = to_phy_device(dev); 349 350 /* 351 * We must stop the state machine manually, otherwise it stops out of 352 * control, possibly with the phydev->lock held. Upon resume, netdev 353 * may call phy routines that try to grab the same lock, and that may 354 * lead to a deadlock. 355 */ 356 if (phydev->attached_dev && phydev->adjust_link) 357 phy_stop_machine(phydev); 358 359 if (!mdio_bus_phy_may_suspend(phydev)) 360 return 0; 361 362 return phydrv->suspend(phydev); 363 } 364 365 static int mdio_bus_resume(struct device *dev) 366 { 367 struct phy_driver *phydrv = to_phy_driver(dev->driver); 368 struct phy_device *phydev = to_phy_device(dev); 369 int ret; 370 371 if (!mdio_bus_phy_may_suspend(phydev)) 372 goto no_resume; 373 374 ret = phydrv->resume(phydev); 375 if (ret < 0) 376 return ret; 377 378 no_resume: 379 if (phydev->attached_dev && phydev->adjust_link) 380 phy_start_machine(phydev, NULL); 381 382 return 0; 383 } 384 385 static int mdio_bus_restore(struct device *dev) 386 { 387 struct phy_device *phydev = to_phy_device(dev); 388 struct net_device *netdev = phydev->attached_dev; 389 int ret; 390 391 if (!netdev) 392 return 0; 393 394 ret = phy_init_hw(phydev); 395 if (ret < 0) 396 return ret; 397 398 /* The PHY needs to renegotiate. */ 399 phydev->link = 0; 400 phydev->state = PHY_UP; 401 402 phy_start_machine(phydev, NULL); 403 404 return 0; 405 } 406 407 static struct dev_pm_ops mdio_bus_pm_ops = { 408 .suspend = mdio_bus_suspend, 409 .resume = mdio_bus_resume, 410 .freeze = mdio_bus_suspend, 411 .thaw = mdio_bus_resume, 412 .restore = mdio_bus_restore, 413 }; 414 415 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops) 416 417 #else 418 419 #define MDIO_BUS_PM_OPS NULL 420 421 #endif /* CONFIG_PM */ 422 423 struct bus_type mdio_bus_type = { 424 .name = "mdio_bus", 425 .match = mdio_bus_match, 426 .pm = MDIO_BUS_PM_OPS, 427 }; 428 EXPORT_SYMBOL(mdio_bus_type); 429 430 int __init mdio_bus_init(void) 431 { 432 int ret; 433 434 ret = class_register(&mdio_bus_class); 435 if (!ret) { 436 ret = bus_register(&mdio_bus_type); 437 if (ret) 438 class_unregister(&mdio_bus_class); 439 } 440 441 return ret; 442 } 443 444 void mdio_bus_exit(void) 445 { 446 class_unregister(&mdio_bus_class); 447 bus_unregister(&mdio_bus_type); 448 } 449