2 * drivers/net/phy/mdio_bus.c
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>
30 #include <linux/module.h>
31 #include <linux/mii.h>
32 #include <linux/ethtool.h>
33 #include <linux/phy.h>
37 #include <asm/uaccess.h>
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.
44 * Description: called by a bus driver to allocate an mii_bus
45 * structure to fill in.
47 struct mii_bus *mdiobus_alloc_size(size_t size)
50 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
53 /* If we alloc extra space, it should be aligned */
55 alloc_size = aligned_size + size;
57 alloc_size = sizeof(*bus);
59 bus = kzalloc(alloc_size, GFP_KERNEL);
61 bus->state = MDIOBUS_ALLOCATED;
63 bus->priv = (void *)bus + aligned_size;
68 EXPORT_SYMBOL(mdiobus_alloc_size);
71 * mdiobus_release - mii_bus device release callback
72 * @d: the target struct device that contains the mii_bus
74 * Description: called when the last reference to an mii_bus is
75 * dropped, to free the underlying memory.
77 static void mdiobus_release(struct device *d)
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);
86 static struct class mdio_bus_class = {
88 .dev_release = mdiobus_release,
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)
95 return dev->of_node == mdio_bus_np;
98 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
99 * @mdio_np: Pointer to the mii_bus.
101 * Returns a pointer to the mii_bus, or NULL if none found.
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().
108 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
115 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
118 return d ? to_mii_bus(d) : NULL;
120 EXPORT_SYMBOL(of_mdio_find_bus);
124 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
125 * @bus: target mii_bus
127 * Description: Called by a bus driver to bring up all the PHYs
128 * on a given bus, and attach them to the bus.
130 * Returns 0 on success or < 0 on error.
132 int mdiobus_register(struct mii_bus *bus)
136 if (NULL == bus || NULL == bus->name ||
141 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
142 bus->state != MDIOBUS_UNREGISTERED);
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);
149 err = device_register(&bus->dev);
151 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
155 mutex_init(&bus->mdio_lock);
160 for (i = 0; i < PHY_MAX_ADDR; i++) {
161 if ((bus->phy_mask & (1 << i)) == 0) {
162 struct phy_device *phydev;
164 phydev = mdiobus_scan(bus, i);
165 if (IS_ERR(phydev)) {
166 err = PTR_ERR(phydev);
172 bus->state = MDIOBUS_REGISTERED;
173 pr_info("%s: probed\n", bus->name);
179 device_unregister(&bus->phy_map[i]->dev);
181 device_del(&bus->dev);
184 EXPORT_SYMBOL(mdiobus_register);
186 void mdiobus_unregister(struct mii_bus *bus)
190 BUG_ON(bus->state != MDIOBUS_REGISTERED);
191 bus->state = MDIOBUS_UNREGISTERED;
193 device_del(&bus->dev);
194 for (i = 0; i < PHY_MAX_ADDR; i++) {
196 device_unregister(&bus->phy_map[i]->dev);
197 bus->phy_map[i] = NULL;
200 EXPORT_SYMBOL(mdiobus_unregister);
203 * mdiobus_free - free a struct mii_bus
204 * @bus: mii_bus to free
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
210 void mdiobus_free(struct mii_bus *bus)
213 * For compatibility with error handling in drivers.
215 if (bus->state == MDIOBUS_ALLOCATED) {
220 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
221 bus->state = MDIOBUS_RELEASED;
223 put_device(&bus->dev);
225 EXPORT_SYMBOL(mdiobus_free);
227 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
229 struct phy_device *phydev;
232 phydev = get_phy_device(bus, addr);
233 if (IS_ERR(phydev) || phydev == NULL)
236 err = phy_device_register(phydev);
238 phy_device_free(phydev);
244 EXPORT_SYMBOL(mdiobus_scan);
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
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.
256 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
260 BUG_ON(in_interrupt());
262 mutex_lock(&bus->mdio_lock);
263 retval = bus->read(bus, addr, regnum);
264 mutex_unlock(&bus->mdio_lock);
268 EXPORT_SYMBOL(mdiobus_read);
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
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.
281 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
285 BUG_ON(in_interrupt());
287 mutex_lock(&bus->mdio_lock);
288 err = bus->write(bus, addr, regnum, val);
289 mutex_unlock(&bus->mdio_lock);
293 EXPORT_SYMBOL(mdiobus_write);
296 * mdio_bus_match - determine if given PHY driver supports the given PHY device
297 * @dev: target PHY device
298 * @drv: given PHY driver
300 * Description: Given a PHY device, and a PHY driver, return 1 if
301 * the driver supports the device. Otherwise, return 0.
303 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
305 struct phy_device *phydev = to_phy_device(dev);
306 struct phy_driver *phydrv = to_phy_driver(drv);
308 return ((phydrv->phy_id & phydrv->phy_id_mask) ==
309 (phydev->phy_id & phydrv->phy_id_mask));
314 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
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;
320 if (!drv || !phydrv->suspend)
323 /* PHY not attached? May suspend. */
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.
331 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
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,
339 if (device_may_wakeup(&netdev->dev))
345 static int mdio_bus_suspend(struct device *dev)
347 struct phy_driver *phydrv = to_phy_driver(dev->driver);
348 struct phy_device *phydev = to_phy_device(dev);
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.
356 if (phydev->attached_dev && phydev->adjust_link)
357 phy_stop_machine(phydev);
359 if (!mdio_bus_phy_may_suspend(phydev))
362 return phydrv->suspend(phydev);
365 static int mdio_bus_resume(struct device *dev)
367 struct phy_driver *phydrv = to_phy_driver(dev->driver);
368 struct phy_device *phydev = to_phy_device(dev);
371 if (!mdio_bus_phy_may_suspend(phydev))
374 ret = phydrv->resume(phydev);
379 if (phydev->attached_dev && phydev->adjust_link)
380 phy_start_machine(phydev, NULL);
385 static int mdio_bus_restore(struct device *dev)
387 struct phy_device *phydev = to_phy_device(dev);
388 struct net_device *netdev = phydev->attached_dev;
394 ret = phy_init_hw(phydev);
398 /* The PHY needs to renegotiate. */
400 phydev->state = PHY_UP;
402 phy_start_machine(phydev, NULL);
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,
415 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
419 #define MDIO_BUS_PM_OPS NULL
421 #endif /* CONFIG_PM */
423 struct bus_type mdio_bus_type = {
425 .match = mdio_bus_match,
426 .pm = MDIO_BUS_PM_OPS,
428 EXPORT_SYMBOL(mdio_bus_type);
430 int __init mdio_bus_init(void)
434 ret = class_register(&mdio_bus_class);
436 ret = bus_register(&mdio_bus_type);
438 class_unregister(&mdio_bus_class);
444 void mdio_bus_exit(void)
446 class_unregister(&mdio_bus_class);
447 bus_unregister(&mdio_bus_type);