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 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 } 371