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 * 59 * Description: called when the last reference to an mii_bus is 60 * dropped, to free the underlying memory. 61 */ 62 static void mdiobus_release(struct device *d) 63 { 64 struct mii_bus *bus = to_mii_bus(d); 65 BUG_ON(bus->state != MDIOBUS_RELEASED); 66 kfree(bus); 67 } 68 69 static struct class mdio_bus_class = { 70 .name = "mdio_bus", 71 .dev_release = mdiobus_release, 72 }; 73 74 /** 75 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus 76 * @bus: target mii_bus 77 * 78 * Description: Called by a bus driver to bring up all the PHYs 79 * on a given bus, and attach them to the bus. 80 * 81 * Returns 0 on success or < 0 on error. 82 */ 83 int mdiobus_register(struct mii_bus *bus) 84 { 85 int i; 86 int err = 0; 87 88 if (NULL == bus || NULL == bus->name || 89 NULL == bus->read || 90 NULL == bus->write) 91 return -EINVAL; 92 93 BUG_ON(bus->state != MDIOBUS_ALLOCATED && 94 bus->state != MDIOBUS_UNREGISTERED); 95 96 bus->dev.parent = bus->parent; 97 bus->dev.class = &mdio_bus_class; 98 bus->dev.groups = NULL; 99 memcpy(bus->dev.bus_id, bus->id, MII_BUS_ID_SIZE); 100 101 err = device_register(&bus->dev); 102 if (err) { 103 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id); 104 return -EINVAL; 105 } 106 107 bus->state = MDIOBUS_REGISTERED; 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 } 123 } 124 125 pr_info("%s: probed\n", bus->name); 126 127 return err; 128 } 129 EXPORT_SYMBOL(mdiobus_register); 130 131 void mdiobus_unregister(struct mii_bus *bus) 132 { 133 int i; 134 135 BUG_ON(bus->state != MDIOBUS_REGISTERED); 136 bus->state = MDIOBUS_UNREGISTERED; 137 138 device_unregister(&bus->dev); 139 for (i = 0; i < PHY_MAX_ADDR; i++) { 140 if (bus->phy_map[i]) 141 device_unregister(&bus->phy_map[i]->dev); 142 } 143 } 144 EXPORT_SYMBOL(mdiobus_unregister); 145 146 /** 147 * mdiobus_free - free a struct mii_bus 148 * @bus: mii_bus to free 149 * 150 * This function releases the reference to the underlying device 151 * object in the mii_bus. If this is the last reference, the mii_bus 152 * will be freed. 153 */ 154 void mdiobus_free(struct mii_bus *bus) 155 { 156 /* 157 * For compatibility with error handling in drivers. 158 */ 159 if (bus->state == MDIOBUS_ALLOCATED) { 160 kfree(bus); 161 return; 162 } 163 164 BUG_ON(bus->state != MDIOBUS_UNREGISTERED); 165 bus->state = MDIOBUS_RELEASED; 166 167 put_device(&bus->dev); 168 } 169 EXPORT_SYMBOL(mdiobus_free); 170 171 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) 172 { 173 struct phy_device *phydev; 174 int err; 175 176 phydev = get_phy_device(bus, addr); 177 if (IS_ERR(phydev) || phydev == NULL) 178 return phydev; 179 180 /* There's a PHY at this address 181 * We need to set: 182 * 1) IRQ 183 * 2) bus_id 184 * 3) parent 185 * 4) bus 186 * 5) mii_bus 187 * And, we need to register it */ 188 189 phydev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL; 190 191 phydev->dev.parent = bus->parent; 192 phydev->dev.bus = &mdio_bus_type; 193 snprintf(phydev->dev.bus_id, BUS_ID_SIZE, PHY_ID_FMT, bus->id, addr); 194 195 phydev->bus = bus; 196 197 /* Run all of the fixups for this PHY */ 198 phy_scan_fixups(phydev); 199 200 err = device_register(&phydev->dev); 201 if (err) { 202 printk(KERN_ERR "phy %d failed to register\n", addr); 203 phy_device_free(phydev); 204 phydev = NULL; 205 } 206 207 bus->phy_map[addr] = phydev; 208 209 return phydev; 210 } 211 EXPORT_SYMBOL(mdiobus_scan); 212 213 /** 214 * mdiobus_read - Convenience function for reading a given MII mgmt register 215 * @bus: the mii_bus struct 216 * @addr: the phy address 217 * @regnum: register number to read 218 * 219 * NOTE: MUST NOT be called from interrupt context, 220 * because the bus read/write functions may wait for an interrupt 221 * to conclude the operation. 222 */ 223 int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum) 224 { 225 int retval; 226 227 BUG_ON(in_interrupt()); 228 229 mutex_lock(&bus->mdio_lock); 230 retval = bus->read(bus, addr, regnum); 231 mutex_unlock(&bus->mdio_lock); 232 233 return retval; 234 } 235 EXPORT_SYMBOL(mdiobus_read); 236 237 /** 238 * mdiobus_write - Convenience function for writing a given MII mgmt register 239 * @bus: the mii_bus struct 240 * @addr: the phy address 241 * @regnum: register number to write 242 * @val: value to write to @regnum 243 * 244 * NOTE: MUST NOT be called from interrupt context, 245 * because the bus read/write functions may wait for an interrupt 246 * to conclude the operation. 247 */ 248 int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val) 249 { 250 int err; 251 252 BUG_ON(in_interrupt()); 253 254 mutex_lock(&bus->mdio_lock); 255 err = bus->write(bus, addr, regnum, val); 256 mutex_unlock(&bus->mdio_lock); 257 258 return err; 259 } 260 EXPORT_SYMBOL(mdiobus_write); 261 262 /** 263 * mdio_bus_match - determine if given PHY driver supports the given PHY device 264 * @dev: target PHY device 265 * @drv: given PHY driver 266 * 267 * Description: Given a PHY device, and a PHY driver, return 1 if 268 * the driver supports the device. Otherwise, return 0. 269 */ 270 static int mdio_bus_match(struct device *dev, struct device_driver *drv) 271 { 272 struct phy_device *phydev = to_phy_device(dev); 273 struct phy_driver *phydrv = to_phy_driver(drv); 274 275 return ((phydrv->phy_id & phydrv->phy_id_mask) == 276 (phydev->phy_id & phydrv->phy_id_mask)); 277 } 278 279 /* Suspend and resume. Copied from platform_suspend and 280 * platform_resume 281 */ 282 static int mdio_bus_suspend(struct device * dev, pm_message_t state) 283 { 284 int ret = 0; 285 struct device_driver *drv = dev->driver; 286 287 if (drv && drv->suspend) 288 ret = drv->suspend(dev, state); 289 290 return ret; 291 } 292 293 static int mdio_bus_resume(struct device * dev) 294 { 295 int ret = 0; 296 struct device_driver *drv = dev->driver; 297 298 if (drv && drv->resume) 299 ret = drv->resume(dev); 300 301 return ret; 302 } 303 304 struct bus_type mdio_bus_type = { 305 .name = "mdio_bus", 306 .match = mdio_bus_match, 307 .suspend = mdio_bus_suspend, 308 .resume = mdio_bus_resume, 309 }; 310 EXPORT_SYMBOL(mdio_bus_type); 311 312 int __init mdio_bus_init(void) 313 { 314 int ret; 315 316 ret = class_register(&mdio_bus_class); 317 if (!ret) { 318 ret = bus_register(&mdio_bus_type); 319 if (ret) 320 class_unregister(&mdio_bus_class); 321 } 322 323 return ret; 324 } 325 326 void mdio_bus_exit(void) 327 { 328 class_unregister(&mdio_bus_class); 329 bus_unregister(&mdio_bus_type); 330 } 331