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.
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/unistd.h>
23 #include <linux/slab.h>
24 #include <linux/interrupt.h>
25 #include <linux/init.h>
26 #include <linux/delay.h>
27 #include <linux/device.h>
28 #include <linux/of_device.h>
29 #include <linux/netdevice.h>
30 #include <linux/etherdevice.h>
31 #include <linux/skbuff.h>
32 #include <linux/spinlock.h>
34 #include <linux/module.h>
35 #include <linux/mii.h>
36 #include <linux/ethtool.h>
37 #include <linux/phy.h>
41 #include <asm/uaccess.h>
44 * mdiobus_alloc_size - allocate a mii_bus structure
45 * @size: extra amount of memory to allocate for private storage.
46 * If non-zero, then bus->priv is points to that memory.
48 * Description: called by a bus driver to allocate an mii_bus
49 * structure to fill in.
51 struct mii_bus *mdiobus_alloc_size(size_t size)
54 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
57 /* If we alloc extra space, it should be aligned */
59 alloc_size = aligned_size + size;
61 alloc_size = sizeof(*bus);
63 bus = kzalloc(alloc_size, GFP_KERNEL);
65 bus->state = MDIOBUS_ALLOCATED;
67 bus->priv = (void *)bus + aligned_size;
72 EXPORT_SYMBOL(mdiobus_alloc_size);
75 * mdiobus_release - mii_bus device release callback
76 * @d: the target struct device that contains the mii_bus
78 * Description: called when the last reference to an mii_bus is
79 * dropped, to free the underlying memory.
81 static void mdiobus_release(struct device *d)
83 struct mii_bus *bus = to_mii_bus(d);
84 BUG_ON(bus->state != MDIOBUS_RELEASED &&
85 /* for compatibility with error handling in drivers */
86 bus->state != MDIOBUS_ALLOCATED);
90 static struct class mdio_bus_class = {
92 .dev_release = mdiobus_release,
95 #if IS_ENABLED(CONFIG_OF_MDIO)
96 /* Helper function for of_mdio_find_bus */
97 static int of_mdio_bus_match(struct device *dev, void *mdio_bus_np)
99 return dev->of_node == mdio_bus_np;
102 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
103 * @mdio_bus_np: Pointer to the mii_bus.
105 * Returns a pointer to the mii_bus, or NULL if none found.
107 * Because the association of a device_node and mii_bus is made via
108 * of_mdiobus_register(), the mii_bus cannot be found before it is
109 * registered with of_mdiobus_register().
112 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
119 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
122 return d ? to_mii_bus(d) : NULL;
124 EXPORT_SYMBOL(of_mdio_find_bus);
128 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
129 * @bus: target mii_bus
131 * Description: Called by a bus driver to bring up all the PHYs
132 * on a given bus, and attach them to the bus.
134 * Returns 0 on success or < 0 on error.
136 int mdiobus_register(struct mii_bus *bus)
140 if (NULL == bus || NULL == bus->name ||
145 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
146 bus->state != MDIOBUS_UNREGISTERED);
148 bus->dev.parent = bus->parent;
149 bus->dev.class = &mdio_bus_class;
150 bus->dev.groups = NULL;
151 dev_set_name(&bus->dev, "%s", bus->id);
153 err = device_register(&bus->dev);
155 pr_err("mii_bus %s failed to register\n", bus->id);
159 mutex_init(&bus->mdio_lock);
164 for (i = 0; i < PHY_MAX_ADDR; i++) {
165 if ((bus->phy_mask & (1 << i)) == 0) {
166 struct phy_device *phydev;
168 phydev = mdiobus_scan(bus, i);
169 if (IS_ERR(phydev)) {
170 err = PTR_ERR(phydev);
176 bus->state = MDIOBUS_REGISTERED;
177 pr_info("%s: probed\n", bus->name);
183 device_unregister(&bus->phy_map[i]->dev);
185 device_del(&bus->dev);
188 EXPORT_SYMBOL(mdiobus_register);
190 void mdiobus_unregister(struct mii_bus *bus)
194 BUG_ON(bus->state != MDIOBUS_REGISTERED);
195 bus->state = MDIOBUS_UNREGISTERED;
197 device_del(&bus->dev);
198 for (i = 0; i < PHY_MAX_ADDR; i++) {
200 device_unregister(&bus->phy_map[i]->dev);
201 bus->phy_map[i] = NULL;
204 EXPORT_SYMBOL(mdiobus_unregister);
207 * mdiobus_free - free a struct mii_bus
208 * @bus: mii_bus to free
210 * This function releases the reference to the underlying device
211 * object in the mii_bus. If this is the last reference, the mii_bus
214 void mdiobus_free(struct mii_bus *bus)
217 * For compatibility with error handling in drivers.
219 if (bus->state == MDIOBUS_ALLOCATED) {
224 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
225 bus->state = MDIOBUS_RELEASED;
227 put_device(&bus->dev);
229 EXPORT_SYMBOL(mdiobus_free);
231 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
233 struct phy_device *phydev;
236 phydev = get_phy_device(bus, addr, false);
237 if (IS_ERR(phydev) || phydev == NULL)
240 err = phy_device_register(phydev);
242 phy_device_free(phydev);
248 EXPORT_SYMBOL(mdiobus_scan);
251 * mdiobus_read - Convenience function for reading a given MII mgmt register
252 * @bus: the mii_bus struct
253 * @addr: the phy address
254 * @regnum: register number to read
256 * NOTE: MUST NOT be called from interrupt context,
257 * because the bus read/write functions may wait for an interrupt
258 * to conclude the operation.
260 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
264 BUG_ON(in_interrupt());
266 mutex_lock(&bus->mdio_lock);
267 retval = bus->read(bus, addr, regnum);
268 mutex_unlock(&bus->mdio_lock);
272 EXPORT_SYMBOL(mdiobus_read);
275 * mdiobus_write - Convenience function for writing a given MII mgmt register
276 * @bus: the mii_bus struct
277 * @addr: the phy address
278 * @regnum: register number to write
279 * @val: value to write to @regnum
281 * NOTE: MUST NOT be called from interrupt context,
282 * because the bus read/write functions may wait for an interrupt
283 * to conclude the operation.
285 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
289 BUG_ON(in_interrupt());
291 mutex_lock(&bus->mdio_lock);
292 err = bus->write(bus, addr, regnum, val);
293 mutex_unlock(&bus->mdio_lock);
297 EXPORT_SYMBOL(mdiobus_write);
300 * mdio_bus_match - determine if given PHY driver supports the given PHY device
301 * @dev: target PHY device
302 * @drv: given PHY driver
304 * Description: Given a PHY device, and a PHY driver, return 1 if
305 * the driver supports the device. Otherwise, return 0.
307 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
309 struct phy_device *phydev = to_phy_device(dev);
310 struct phy_driver *phydrv = to_phy_driver(drv);
312 if (of_driver_match_device(dev, drv))
315 if (phydrv->match_phy_device)
316 return phydrv->match_phy_device(phydev);
318 return ((phydrv->phy_id & phydrv->phy_id_mask) ==
319 (phydev->phy_id & phydrv->phy_id_mask));
324 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
326 struct device_driver *drv = phydev->dev.driver;
327 struct phy_driver *phydrv = to_phy_driver(drv);
328 struct net_device *netdev = phydev->attached_dev;
330 if (!drv || !phydrv->suspend)
333 /* PHY not attached? May suspend. */
338 * Don't suspend PHY if the attched netdev parent may wakeup.
339 * The parent may point to a PCI device, as in tg3 driver.
341 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
345 * Also don't suspend PHY if the netdev itself may wakeup. This
346 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
349 if (device_may_wakeup(&netdev->dev))
355 static int mdio_bus_suspend(struct device *dev)
357 struct phy_driver *phydrv = to_phy_driver(dev->driver);
358 struct phy_device *phydev = to_phy_device(dev);
361 * We must stop the state machine manually, otherwise it stops out of
362 * control, possibly with the phydev->lock held. Upon resume, netdev
363 * may call phy routines that try to grab the same lock, and that may
364 * lead to a deadlock.
366 if (phydev->attached_dev && phydev->adjust_link)
367 phy_stop_machine(phydev);
369 if (!mdio_bus_phy_may_suspend(phydev))
372 return phydrv->suspend(phydev);
375 static int mdio_bus_resume(struct device *dev)
377 struct phy_driver *phydrv = to_phy_driver(dev->driver);
378 struct phy_device *phydev = to_phy_device(dev);
381 if (!mdio_bus_phy_may_suspend(phydev))
384 ret = phydrv->resume(phydev);
389 if (phydev->attached_dev && phydev->adjust_link)
390 phy_start_machine(phydev, NULL);
395 static int mdio_bus_restore(struct device *dev)
397 struct phy_device *phydev = to_phy_device(dev);
398 struct net_device *netdev = phydev->attached_dev;
404 ret = phy_init_hw(phydev);
408 /* The PHY needs to renegotiate. */
410 phydev->state = PHY_UP;
412 phy_start_machine(phydev, NULL);
417 static struct dev_pm_ops mdio_bus_pm_ops = {
418 .suspend = mdio_bus_suspend,
419 .resume = mdio_bus_resume,
420 .freeze = mdio_bus_suspend,
421 .thaw = mdio_bus_resume,
422 .restore = mdio_bus_restore,
425 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
429 #define MDIO_BUS_PM_OPS NULL
431 #endif /* CONFIG_PM */
433 struct bus_type mdio_bus_type = {
435 .match = mdio_bus_match,
436 .pm = MDIO_BUS_PM_OPS,
438 EXPORT_SYMBOL(mdio_bus_type);
440 int __init mdio_bus_init(void)
444 ret = class_register(&mdio_bus_class);
446 ret = bus_register(&mdio_bus_type);
448 class_unregister(&mdio_bus_class);
454 void mdio_bus_exit(void)
456 class_unregister(&mdio_bus_class);
457 bus_unregister(&mdio_bus_type);