Revert "b43: Enforce DMA descriptor memory constraints"
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / phy / mdio_bus.c
blobbd4e8d72dc08fa7e5a14822ef9d577cabdf3a185
1 /*
2 * drivers/net/phy/mdio_bus.c
4 * MDIO Bus interface
6 * Author: Andy Fleming
8 * Copyright (c) 2004 Freescale Semiconductor, Inc.
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.
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>
35 #include <asm/io.h>
36 #include <asm/irq.h>
37 #include <asm/uaccess.h>
39 /**
40 * mdiobus_alloc - allocate a mii_bus structure
42 * Description: called by a bus driver to allocate an mii_bus
43 * structure to fill in.
45 struct mii_bus *mdiobus_alloc(void)
47 struct mii_bus *bus;
49 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
50 if (bus != NULL)
51 bus->state = MDIOBUS_ALLOCATED;
53 return bus;
55 EXPORT_SYMBOL(mdiobus_alloc);
57 /**
58 * mdiobus_release - mii_bus device release callback
59 * @d: the target struct device that contains the mii_bus
61 * Description: called when the last reference to an mii_bus is
62 * dropped, to free the underlying memory.
64 static void mdiobus_release(struct device *d)
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);
73 static struct class mdio_bus_class = {
74 .name = "mdio_bus",
75 .dev_release = mdiobus_release,
78 /**
79 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
80 * @bus: target mii_bus
82 * Description: Called by a bus driver to bring up all the PHYs
83 * on a given bus, and attach them to the bus.
85 * Returns 0 on success or < 0 on error.
87 int mdiobus_register(struct mii_bus *bus)
89 int i, err;
91 if (NULL == bus || NULL == bus->name ||
92 NULL == bus->read ||
93 NULL == bus->write)
94 return -EINVAL;
96 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
97 bus->state != MDIOBUS_UNREGISTERED);
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);
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;
110 mutex_init(&bus->mdio_lock);
112 if (bus->reset)
113 bus->reset(bus);
115 for (i = 0; i < PHY_MAX_ADDR; i++) {
116 if ((bus->phy_mask & (1 << i)) == 0) {
117 struct phy_device *phydev;
119 phydev = mdiobus_scan(bus, i);
120 if (IS_ERR(phydev)) {
121 err = PTR_ERR(phydev);
122 goto error;
127 bus->state = MDIOBUS_REGISTERED;
128 pr_info("%s: probed\n", bus->name);
129 return 0;
131 error:
132 while (--i >= 0) {
133 if (bus->phy_map[i])
134 device_unregister(&bus->phy_map[i]->dev);
136 device_del(&bus->dev);
137 return err;
139 EXPORT_SYMBOL(mdiobus_register);
141 void mdiobus_unregister(struct mii_bus *bus)
143 int i;
145 BUG_ON(bus->state != MDIOBUS_REGISTERED);
146 bus->state = MDIOBUS_UNREGISTERED;
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;
155 EXPORT_SYMBOL(mdiobus_unregister);
158 * mdiobus_free - free a struct mii_bus
159 * @bus: mii_bus to free
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.
165 void mdiobus_free(struct mii_bus *bus)
168 * For compatibility with error handling in drivers.
170 if (bus->state == MDIOBUS_ALLOCATED) {
171 kfree(bus);
172 return;
175 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
176 bus->state = MDIOBUS_RELEASED;
178 put_device(&bus->dev);
180 EXPORT_SYMBOL(mdiobus_free);
182 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
184 struct phy_device *phydev;
185 int err;
187 phydev = get_phy_device(bus, addr);
188 if (IS_ERR(phydev) || phydev == NULL)
189 return phydev;
191 err = phy_device_register(phydev);
192 if (err) {
193 phy_device_free(phydev);
194 return NULL;
197 return phydev;
199 EXPORT_SYMBOL(mdiobus_scan);
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
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.
211 int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum)
213 int retval;
215 BUG_ON(in_interrupt());
217 mutex_lock(&bus->mdio_lock);
218 retval = bus->read(bus, addr, regnum);
219 mutex_unlock(&bus->mdio_lock);
221 return retval;
223 EXPORT_SYMBOL(mdiobus_read);
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
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.
236 int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val)
238 int err;
240 BUG_ON(in_interrupt());
242 mutex_lock(&bus->mdio_lock);
243 err = bus->write(bus, addr, regnum, val);
244 mutex_unlock(&bus->mdio_lock);
246 return err;
248 EXPORT_SYMBOL(mdiobus_write);
251 * mdio_bus_match - determine if given PHY driver supports the given PHY device
252 * @dev: target PHY device
253 * @drv: given PHY driver
255 * Description: Given a PHY device, and a PHY driver, return 1 if
256 * the driver supports the device. Otherwise, return 0.
258 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
260 struct phy_device *phydev = to_phy_device(dev);
261 struct phy_driver *phydrv = to_phy_driver(drv);
263 return ((phydrv->phy_id & phydrv->phy_id_mask) ==
264 (phydev->phy_id & phydrv->phy_id_mask));
267 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
269 struct device_driver *drv = phydev->dev.driver;
270 struct phy_driver *phydrv = to_phy_driver(drv);
271 struct net_device *netdev = phydev->attached_dev;
273 if (!drv || !phydrv->suspend)
274 return false;
276 /* PHY not attached? May suspend. */
277 if (!netdev)
278 return true;
281 * Don't suspend PHY if the attched netdev parent may wakeup.
282 * The parent may point to a PCI device, as in tg3 driver.
284 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
285 return false;
288 * Also don't suspend PHY if the netdev itself may wakeup. This
289 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
290 * e.g. SoC devices.
292 if (device_may_wakeup(&netdev->dev))
293 return false;
295 return true;
298 /* Suspend and resume. Copied from platform_suspend and
299 * platform_resume
301 static int mdio_bus_suspend(struct device * dev, pm_message_t state)
303 struct phy_driver *phydrv = to_phy_driver(dev->driver);
304 struct phy_device *phydev = to_phy_device(dev);
306 if (!mdio_bus_phy_may_suspend(phydev))
307 return 0;
308 return phydrv->suspend(phydev);
311 static int mdio_bus_resume(struct device * dev)
313 struct phy_driver *phydrv = to_phy_driver(dev->driver);
314 struct phy_device *phydev = to_phy_device(dev);
316 if (!mdio_bus_phy_may_suspend(phydev))
317 return 0;
318 return phydrv->resume(phydev);
321 struct bus_type mdio_bus_type = {
322 .name = "mdio_bus",
323 .match = mdio_bus_match,
324 .suspend = mdio_bus_suspend,
325 .resume = mdio_bus_resume,
327 EXPORT_SYMBOL(mdio_bus_type);
329 int __init mdio_bus_init(void)
331 int ret;
333 ret = class_register(&mdio_bus_class);
334 if (!ret) {
335 ret = bus_register(&mdio_bus_type);
336 if (ret)
337 class_unregister(&mdio_bus_class);
340 return ret;
343 void mdio_bus_exit(void)
345 class_unregister(&mdio_bus_class);
346 bus_unregister(&mdio_bus_type);