[deliverable/linux.git] / drivers / net / phy / mdio_bus.c

/*
 * drivers/net/phy/mdio_bus.c
 *
 * MDIO Bus interface
 *
 * Author: Andy Fleming
 *
 * Copyright (c) 2004 Freescale Semiconductor, Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>

/**
 * mdiobus_alloc_size - allocate a mii_bus structure
 * @size: extra amount of memory to allocate for private storage.
 * If non-zero, then bus->priv is points to that memory.
 *
 * Description: called by a bus driver to allocate an mii_bus
 * structure to fill in.
 */
struct mii_bus *mdiobus_alloc_size(size_t size)
{
	struct mii_bus *bus;
	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
	size_t alloc_size;

	/* If we alloc extra space, it should be aligned */
	if (size)
		alloc_size = aligned_size + size;
	else
		alloc_size = sizeof(*bus);

	bus = kzalloc(alloc_size, GFP_KERNEL);
	if (bus) {
		bus->state = MDIOBUS_ALLOCATED;
		if (size)
			bus->priv = (void *)bus + aligned_size;
	}

	return bus;
}
EXPORT_SYMBOL(mdiobus_alloc_size);

/**
 * mdiobus_release - mii_bus device release callback
 * @d: the target struct device that contains the mii_bus
 *
 * Description: called when the last reference to an mii_bus is
 * dropped, to free the underlying memory.
 */
static void mdiobus_release(struct device *d)
{
	struct mii_bus *bus = to_mii_bus(d);
	BUG_ON(bus->state != MDIOBUS_RELEASED &&
	       /* for compatibility with error handling in drivers */
	       bus->state != MDIOBUS_ALLOCATED);
	kfree(bus);
}

static struct class mdio_bus_class = {
	.name		= "mdio_bus",
	.dev_release	= mdiobus_release,
};

#if IS_ENABLED(CONFIG_OF_MDIO)
/* Helper function for of_mdio_find_bus */
static int of_mdio_bus_match(struct device *dev, void *mdio_bus_np)
{
	return dev->of_node == mdio_bus_np;
}
/**
 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
 * @mdio_bus_np: Pointer to the mii_bus.
 *
 * Returns a pointer to the mii_bus, or NULL if none found.
 *
 * Because the association of a device_node and mii_bus is made via
 * of_mdiobus_register(), the mii_bus cannot be found before it is
 * registered with of_mdiobus_register().
 *
 */
struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
{
	struct device *d;

	if (!mdio_bus_np)
		return NULL;

	d = class_find_device(&mdio_bus_class, NULL,  mdio_bus_np,
			      of_mdio_bus_match);

	return d ? to_mii_bus(d) : NULL;
}
EXPORT_SYMBOL(of_mdio_find_bus);
#endif

/**
 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 * @bus: target mii_bus
 *
 * Description: Called by a bus driver to bring up all the PHYs
 *   on a given bus, and attach them to the bus.
 *
 * Returns 0 on success or < 0 on error.
 */
int mdiobus_register(struct mii_bus *bus)
{
	int i, err;

	if (NULL == bus || NULL == bus->name ||
			NULL == bus->read ||
			NULL == bus->write)
		return -EINVAL;

	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
	       bus->state != MDIOBUS_UNREGISTERED);

	bus->dev.parent = bus->parent;
	bus->dev.class = &mdio_bus_class;
	bus->dev.groups = NULL;
	dev_set_name(&bus->dev, "%s", bus->id);

	err = device_register(&bus->dev);
	if (err) {
		pr_err("mii_bus %s failed to register\n", bus->id);
		return -EINVAL;
	}

	mutex_init(&bus->mdio_lock);

	if (bus->reset)
		bus->reset(bus);

	for (i = 0; i < PHY_MAX_ADDR; i++) {
		if ((bus->phy_mask & (1 << i)) == 0) {
			struct phy_device *phydev;

			phydev = mdiobus_scan(bus, i);
			if (IS_ERR(phydev)) {
				err = PTR_ERR(phydev);
				goto error;
			}
		}
	}

	bus->state = MDIOBUS_REGISTERED;
	pr_info("%s: probed\n", bus->name);
	return 0;

error:
	while (--i >= 0) {
		if (bus->phy_map[i])
			device_unregister(&bus->phy_map[i]->dev);
	}
	device_del(&bus->dev);
	return err;
}
EXPORT_SYMBOL(mdiobus_register);

void mdiobus_unregister(struct mii_bus *bus)
{
	int i;

	BUG_ON(bus->state != MDIOBUS_REGISTERED);
	bus->state = MDIOBUS_UNREGISTERED;

	device_del(&bus->dev);
	for (i = 0; i < PHY_MAX_ADDR; i++) {
		if (bus->phy_map[i])
			device_unregister(&bus->phy_map[i]->dev);
		bus->phy_map[i] = NULL;
	}
}
EXPORT_SYMBOL(mdiobus_unregister);

/**
 * mdiobus_free - free a struct mii_bus
 * @bus: mii_bus to free
 *
 * This function releases the reference to the underlying device
 * object in the mii_bus.  If this is the last reference, the mii_bus
 * will be freed.
 */
void mdiobus_free(struct mii_bus *bus)
{
	/*
	 * For compatibility with error handling in drivers.
	 */
	if (bus->state == MDIOBUS_ALLOCATED) {
		kfree(bus);
		return;
	}

	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
	bus->state = MDIOBUS_RELEASED;

	put_device(&bus->dev);
}
EXPORT_SYMBOL(mdiobus_free);

struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
{
	struct phy_device *phydev;
	int err;

	phydev = get_phy_device(bus, addr, false);
	if (IS_ERR(phydev) || phydev == NULL)
		return phydev;

	err = phy_device_register(phydev);
	if (err) {
		phy_device_free(phydev);
		return NULL;
	}

	return phydev;
}
EXPORT_SYMBOL(mdiobus_scan);

/**
 * mdiobus_read - Convenience function for reading a given MII mgmt register
 * @bus: the mii_bus struct
 * @addr: the phy address
 * @regnum: register number to read
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
{
	int retval;

	BUG_ON(in_interrupt());

	mutex_lock(&bus->mdio_lock);
	retval = bus->read(bus, addr, regnum);
	mutex_unlock(&bus->mdio_lock);

	return retval;
}
EXPORT_SYMBOL(mdiobus_read);

/**
 * mdiobus_write - Convenience function for writing a given MII mgmt register
 * @bus: the mii_bus struct
 * @addr: the phy address
 * @regnum: register number to write
 * @val: value to write to @regnum
 *
 * NOTE: MUST NOT be called from interrupt context,
 * because the bus read/write functions may wait for an interrupt
 * to conclude the operation.
 */
int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
{
	int err;

	BUG_ON(in_interrupt());

	mutex_lock(&bus->mdio_lock);
	err = bus->write(bus, addr, regnum, val);
	mutex_unlock(&bus->mdio_lock);

	return err;
}
EXPORT_SYMBOL(mdiobus_write);

/**
 * mdio_bus_match - determine if given PHY driver supports the given PHY device
 * @dev: target PHY device
 * @drv: given PHY driver
 *
 * Description: Given a PHY device, and a PHY driver, return 1 if
 *   the driver supports the device.  Otherwise, return 0.
 */
static int mdio_bus_match(struct device *dev, struct device_driver *drv)
{
	struct phy_device *phydev = to_phy_device(dev);
	struct phy_driver *phydrv = to_phy_driver(drv);

	return ((phydrv->phy_id & phydrv->phy_id_mask) ==
		(phydev->phy_id & phydrv->phy_id_mask));
}

#ifdef CONFIG_PM

static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
{
	struct device_driver *drv = phydev->dev.driver;
	struct phy_driver *phydrv = to_phy_driver(drv);
	struct net_device *netdev = phydev->attached_dev;

	if (!drv || !phydrv->suspend)
		return false;

	/* PHY not attached? May suspend. */
	if (!netdev)
		return true;

	/*
	 * Don't suspend PHY if the attched netdev parent may wakeup.
	 * The parent may point to a PCI device, as in tg3 driver.
	 */
	if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
		return false;

	/*
	 * Also don't suspend PHY if the netdev itself may wakeup. This
	 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
	 * e.g. SoC devices.
	 */
	if (device_may_wakeup(&netdev->dev))
		return false;

	return true;
}

static int mdio_bus_suspend(struct device *dev)
{
	struct phy_driver *phydrv = to_phy_driver(dev->driver);
	struct phy_device *phydev = to_phy_device(dev);

	/*
	 * We must stop the state machine manually, otherwise it stops out of
	 * control, possibly with the phydev->lock held. Upon resume, netdev
	 * may call phy routines that try to grab the same lock, and that may
	 * lead to a deadlock.
	 */
	if (phydev->attached_dev && phydev->adjust_link)
		phy_stop_machine(phydev);

	if (!mdio_bus_phy_may_suspend(phydev))
		return 0;

	return phydrv->suspend(phydev);
}

static int mdio_bus_resume(struct device *dev)
{
	struct phy_driver *phydrv = to_phy_driver(dev->driver);
	struct phy_device *phydev = to_phy_device(dev);
	int ret;

	if (!mdio_bus_phy_may_suspend(phydev))
		goto no_resume;

	ret = phydrv->resume(phydev);
	if (ret < 0)
		return ret;

no_resume:
	if (phydev->attached_dev && phydev->adjust_link)
		phy_start_machine(phydev, NULL);

	return 0;
}

static int mdio_bus_restore(struct device *dev)
{
	struct phy_device *phydev = to_phy_device(dev);
	struct net_device *netdev = phydev->attached_dev;
	int ret;

	if (!netdev)
		return 0;

	ret = phy_init_hw(phydev);
	if (ret < 0)
		return ret;

	/* The PHY needs to renegotiate. */
	phydev->link = 0;
	phydev->state = PHY_UP;

	phy_start_machine(phydev, NULL);

	return 0;
}

static struct dev_pm_ops mdio_bus_pm_ops = {
	.suspend = mdio_bus_suspend,
	.resume = mdio_bus_resume,
	.freeze = mdio_bus_suspend,
	.thaw = mdio_bus_resume,
	.restore = mdio_bus_restore,
};

#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)

#else

#define MDIO_BUS_PM_OPS NULL

#endif /* CONFIG_PM */

struct bus_type mdio_bus_type = {
	.name		= "mdio_bus",
	.match		= mdio_bus_match,
	.pm		= MDIO_BUS_PM_OPS,
};
EXPORT_SYMBOL(mdio_bus_type);

int __init mdio_bus_init(void)
{
	int ret;

	ret = class_register(&mdio_bus_class);
	if (!ret) {
		ret = bus_register(&mdio_bus_type);
		if (ret)
			class_unregister(&mdio_bus_class);
	}

	return ret;
}

void mdio_bus_exit(void)
{
	class_unregister(&mdio_bus_class);
	bus_unregister(&mdio_bus_type);
}
Commit	Line	Data
00db8189 AF	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	*/
8d242488 JP	16
	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	18
00db8189	19	#include <linux/kernel.h>
00db8189 AF	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>
3d1e4db2	27	#include <linux/device.h>
00db8189 AF	28	#include <linux/netdevice.h>
	29	#include <linux/etherdevice.h>
	30	#include <linux/skbuff.h>
	31	#include <linux/spinlock.h>
	32	#include <linux/mm.h>
	33	#include <linux/module.h>
00db8189 AF	34	#include <linux/mii.h>
	35	#include <linux/ethtool.h>
	36	#include <linux/phy.h>
	37
	38	#include <asm/io.h>
	39	#include <asm/irq.h>
	40	#include <asm/uaccess.h>
	41
298cf9be	42	/**
eb8a54a7	43	* mdiobus_alloc_size - allocate a mii_bus structure
af58f1d6 RD	44	* @size: extra amount of memory to allocate for private storage.
af58f1d6 RD	45	* If non-zero, then bus->priv is points to that memory.
298cf9be LB	46	*
	47	* Description: called by a bus driver to allocate an mii_bus
	48	* structure to fill in.
	49	*/
eb8a54a7	50	struct mii_bus *mdiobus_alloc_size(size_t size)
298cf9be	51	{
46abc021	52	struct mii_bus *bus;
eb8a54a7 TT	53	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
	54	size_t alloc_size;
	55
	56	/* If we alloc extra space, it should be aligned */
	57	if (size)
	58	alloc_size = aligned_size + size;
	59	else
	60	alloc_size = sizeof(*bus);
46abc021	61
eb8a54a7 TT	62	bus = kzalloc(alloc_size, GFP_KERNEL);
eb8a54a7 TT	63	if (bus) {
46abc021	64	bus->state = MDIOBUS_ALLOCATED;
eb8a54a7 TT	65	if (size)
	66	bus->priv = (void *)bus + aligned_size;
	67	}
46abc021 LB	68
46abc021 LB	69	return bus;
298cf9be	70	}
eb8a54a7	71	EXPORT_SYMBOL(mdiobus_alloc_size);
298cf9be	72
46abc021 LB	73	/**
46abc021 LB	74	* mdiobus_release - mii_bus device release callback
78c36b15	75	* @d: the target struct device that contains the mii_bus
46abc021 LB	76	*
	77	* Description: called when the last reference to an mii_bus is
	78	* dropped, to free the underlying memory.
	79	*/
	80	static void mdiobus_release(struct device *d)
	81	{
	82	struct mii_bus *bus = to_mii_bus(d);
161c8d2f KH	83	BUG_ON(bus->state != MDIOBUS_RELEASED &&
	84	/* for compatibility with error handling in drivers */
	85	bus->state != MDIOBUS_ALLOCATED);
46abc021 LB	86	kfree(bus);
	87	}
	88
	89	static struct class mdio_bus_class = {
	90	.name = "mdio_bus",
	91	.dev_release = mdiobus_release,
	92	};
	93
b943fbb0	94	#if IS_ENABLED(CONFIG_OF_MDIO)
25106022 DD	95	/* Helper function for of_mdio_find_bus */
	96	static int of_mdio_bus_match(struct device dev, void mdio_bus_np)
	97	{
	98	return dev->of_node == mdio_bus_np;
	99	}
	100	/**
	101	* of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
f41ef2e7	102	* @mdio_bus_np: Pointer to the mii_bus.
25106022 DD	103	*
	104	* Returns a pointer to the mii_bus, or NULL if none found.
	105	*
	106	* Because the association of a device_node and mii_bus is made via
	107	* of_mdiobus_register(), the mii_bus cannot be found before it is
	108	* registered with of_mdiobus_register().
	109	*
	110	*/
	111	struct mii_bus of_mdio_find_bus(struct device_node mdio_bus_np)
	112	{
	113	struct device *d;
	114
	115	if (!mdio_bus_np)
	116	return NULL;
	117
	118	d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
	119	of_mdio_bus_match);
	120
	121	return d ? to_mii_bus(d) : NULL;
	122	}
	123	EXPORT_SYMBOL(of_mdio_find_bus);
	124	#endif
	125
b3df0da8 RD	126	/**
	127	* mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
	128	* @bus: target mii_bus
e1393456	129	*
b3df0da8 RD	130	* Description: Called by a bus driver to bring up all the PHYs
	131	* on a given bus, and attach them to the bus.
	132	*
	133	* Returns 0 on success or < 0 on error.
e1393456 AF	134	*/
	135	int mdiobus_register(struct mii_bus *bus)
	136	{
161c8d2f	137	int i, err;
e1393456	138
e1393456 AF	139	if (NULL == bus \|\| NULL == bus->name \|\|
	140	NULL == bus->read \|\|
	141	NULL == bus->write)
	142	return -EINVAL;
	143
46abc021 LB	144	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
	145	bus->state != MDIOBUS_UNREGISTERED);
	146
	147	bus->dev.parent = bus->parent;
	148	bus->dev.class = &mdio_bus_class;
	149	bus->dev.groups = NULL;
036b6687	150	dev_set_name(&bus->dev, "%s", bus->id);
46abc021 LB	151
	152	err = device_register(&bus->dev);
	153	if (err) {
8d242488	154	pr_err("mii_bus %s failed to register\n", bus->id);
46abc021 LB	155	return -EINVAL;
	156	}
	157
d1e7fe4d AB	158	mutex_init(&bus->mdio_lock);
d1e7fe4d AB	159
e1393456 AF	160	if (bus->reset)
	161	bus->reset(bus);
	162
	163	for (i = 0; i < PHY_MAX_ADDR; i++) {
4fd5f812 LB	164	if ((bus->phy_mask & (1 << i)) == 0) {
4fd5f812 LB	165	struct phy_device *phydev;
e1393456	166
4fd5f812	167	phydev = mdiobus_scan(bus, i);
161c8d2f	168	if (IS_ERR(phydev)) {
4fd5f812	169	err = PTR_ERR(phydev);
161c8d2f KH	170	goto error;
161c8d2f KH	171	}
64b1c2b4	172	}
e1393456 AF	173	}
e1393456 AF	174
161c8d2f	175	bus->state = MDIOBUS_REGISTERED;
e1393456	176	pr_info("%s: probed\n", bus->name);
161c8d2f	177	return 0;
e1393456	178
161c8d2f KH	179	error:
	180	while (--i >= 0) {
	181	if (bus->phy_map[i])
	182	device_unregister(&bus->phy_map[i]->dev);
	183	}
	184	device_del(&bus->dev);
e1393456 AF	185	return err;
	186	}
	187	EXPORT_SYMBOL(mdiobus_register);
	188
	189	void mdiobus_unregister(struct mii_bus *bus)
	190	{
	191	int i;
	192
46abc021 LB	193	BUG_ON(bus->state != MDIOBUS_REGISTERED);
	194	bus->state = MDIOBUS_UNREGISTERED;
	195
3e44017b	196	device_del(&bus->dev);
e1393456	197	for (i = 0; i < PHY_MAX_ADDR; i++) {
6f4a7f41	198	if (bus->phy_map[i])
e1393456	199	device_unregister(&bus->phy_map[i]->dev);
4dea547f	200	bus->phy_map[i] = NULL;
e1393456 AF	201	}
	202	}
	203	EXPORT_SYMBOL(mdiobus_unregister);
	204
298cf9be LB	205	/**
	206	* mdiobus_free - free a struct mii_bus
	207	* @bus: mii_bus to free
	208	*
46abc021 LB	209	* This function releases the reference to the underlying device
	210	* object in the mii_bus. If this is the last reference, the mii_bus
	211	* will be freed.
298cf9be LB	212	*/
	213	void mdiobus_free(struct mii_bus *bus)
	214	{
46abc021 LB	215	/*
	216	* For compatibility with error handling in drivers.
	217	*/
	218	if (bus->state == MDIOBUS_ALLOCATED) {
	219	kfree(bus);
	220	return;
	221	}
	222
	223	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
	224	bus->state = MDIOBUS_RELEASED;
	225
	226	put_device(&bus->dev);
298cf9be LB	227	}
	228	EXPORT_SYMBOL(mdiobus_free);
	229
4fd5f812 LB	230	struct phy_device mdiobus_scan(struct mii_bus bus, int addr)
	231	{
	232	struct phy_device *phydev;
	233	int err;
	234
ac28b9f8	235	phydev = get_phy_device(bus, addr, false);
4fd5f812 LB	236	if (IS_ERR(phydev) \|\| phydev == NULL)
	237	return phydev;
	238
4dea547f	239	err = phy_device_register(phydev);
4fd5f812	240	if (err) {
4fd5f812	241	phy_device_free(phydev);
4dea547f	242	return NULL;
4fd5f812 LB	243	}
4fd5f812 LB	244
4fd5f812 LB	245	return phydev;
	246	}
	247	EXPORT_SYMBOL(mdiobus_scan);
	248
2e888103 LB	249	/**
	250	* mdiobus_read - Convenience function for reading a given MII mgmt register
	251	* @bus: the mii_bus struct
	252	* @addr: the phy address
	253	* @regnum: register number to read
	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	*/
abf35df2	259	int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
2e888103 LB	260	{
	261	int retval;
	262
	263	BUG_ON(in_interrupt());
	264
	265	mutex_lock(&bus->mdio_lock);
	266	retval = bus->read(bus, addr, regnum);
	267	mutex_unlock(&bus->mdio_lock);
	268
	269	return retval;
	270	}
	271	EXPORT_SYMBOL(mdiobus_read);
	272
	273	/**
	274	* mdiobus_write - Convenience function for writing a given MII mgmt register
	275	* @bus: the mii_bus struct
	276	* @addr: the phy address
	277	* @regnum: register number to write
	278	* @val: value to write to @regnum
	279	*
	280	* NOTE: MUST NOT be called from interrupt context,
	281	* because the bus read/write functions may wait for an interrupt
	282	* to conclude the operation.
	283	*/
abf35df2	284	int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
2e888103 LB	285	{
	286	int err;
	287
	288	BUG_ON(in_interrupt());
	289
	290	mutex_lock(&bus->mdio_lock);
	291	err = bus->write(bus, addr, regnum, val);
	292	mutex_unlock(&bus->mdio_lock);
	293
	294	return err;
	295	}
	296	EXPORT_SYMBOL(mdiobus_write);
	297
b3df0da8 RD	298	/**
	299	* mdio_bus_match - determine if given PHY driver supports the given PHY device
	300	* @dev: target PHY device
	301	* @drv: given PHY driver
00db8189	302	*
b3df0da8 RD	303	* Description: Given a PHY device, and a PHY driver, return 1 if
b3df0da8 RD	304	* the driver supports the device. Otherwise, return 0.
00db8189 AF	305	*/
	306	static int mdio_bus_match(struct device dev, struct device_driver drv)
	307	{
	308	struct phy_device *phydev = to_phy_device(dev);
	309	struct phy_driver *phydrv = to_phy_driver(drv);
	310
5f708dd9 KG	311	return ((phydrv->phy_id & phydrv->phy_id_mask) ==
5f708dd9 KG	312	(phydev->phy_id & phydrv->phy_id_mask));
00db8189 AF	313	}
00db8189 AF	314
2f5cb434 AV	315	#ifdef CONFIG_PM
2f5cb434 AV	316
3d1e4db2 AV	317	static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
	318	{
	319	struct device_driver *drv = phydev->dev.driver;
	320	struct phy_driver *phydrv = to_phy_driver(drv);
	321	struct net_device *netdev = phydev->attached_dev;
	322
	323	if (!drv \|\| !phydrv->suspend)
	324	return false;
	325
	326	/* PHY not attached? May suspend. */
	327	if (!netdev)
	328	return true;
	329
	330	/*
	331	* Don't suspend PHY if the attched netdev parent may wakeup.
	332	* The parent may point to a PCI device, as in tg3 driver.
	333	*/
	334	if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
	335	return false;
	336
	337	/*
	338	* Also don't suspend PHY if the netdev itself may wakeup. This
	339	* is the case for devices w/o underlaying pwr. mgmt. aware bus,
	340	* e.g. SoC devices.
	341	*/
	342	if (device_may_wakeup(&netdev->dev))
	343	return false;
	344
	345	return true;
	346	}
	347
2f5cb434	348	static int mdio_bus_suspend(struct device *dev)
00db8189	349	{
3d1e4db2	350	struct phy_driver *phydrv = to_phy_driver(dev->driver);
0f0ca340	351	struct phy_device *phydev = to_phy_device(dev);
00db8189	352
541cd3ee AV	353	/*
	354	* We must stop the state machine manually, otherwise it stops out of
	355	* control, possibly with the phydev->lock held. Upon resume, netdev
	356	* may call phy routines that try to grab the same lock, and that may
	357	* lead to a deadlock.
	358	*/
fddd9101	359	if (phydev->attached_dev && phydev->adjust_link)
541cd3ee AV	360	phy_stop_machine(phydev);
541cd3ee AV	361
3d1e4db2 AV	362	if (!mdio_bus_phy_may_suspend(phydev))
3d1e4db2 AV	363	return 0;
541cd3ee	364
3d1e4db2	365	return phydrv->suspend(phydev);
00db8189 AF	366	}
00db8189 AF	367
2f5cb434	368	static int mdio_bus_resume(struct device *dev)
00db8189	369	{
3d1e4db2	370	struct phy_driver *phydrv = to_phy_driver(dev->driver);
0f0ca340	371	struct phy_device *phydev = to_phy_device(dev);
541cd3ee	372	int ret;
00db8189	373
3d1e4db2	374	if (!mdio_bus_phy_may_suspend(phydev))
541cd3ee AV	375	goto no_resume;
	376
	377	ret = phydrv->resume(phydev);
	378	if (ret < 0)
	379	return ret;
	380
	381	no_resume:
fddd9101	382	if (phydev->attached_dev && phydev->adjust_link)
541cd3ee AV	383	phy_start_machine(phydev, NULL);
	384
	385	return 0;
00db8189 AF	386	}
00db8189 AF	387
2f5cb434 AV	388	static int mdio_bus_restore(struct device *dev)
	389	{
	390	struct phy_device *phydev = to_phy_device(dev);
	391	struct net_device *netdev = phydev->attached_dev;
	392	int ret;
	393
	394	if (!netdev)
	395	return 0;
	396
	397	ret = phy_init_hw(phydev);
	398	if (ret < 0)
	399	return ret;
	400
	401	/* The PHY needs to renegotiate. */
	402	phydev->link = 0;
	403	phydev->state = PHY_UP;
	404
	405	phy_start_machine(phydev, NULL);
	406
	407	return 0;
	408	}
	409
	410	static struct dev_pm_ops mdio_bus_pm_ops = {
	411	.suspend = mdio_bus_suspend,
	412	.resume = mdio_bus_resume,
	413	.freeze = mdio_bus_suspend,
	414	.thaw = mdio_bus_resume,
	415	.restore = mdio_bus_restore,
	416	};
	417
	418	#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
	419
	420	#else
	421
	422	#define MDIO_BUS_PM_OPS NULL
	423
	424	#endif /* CONFIG_PM */
	425
00db8189 AF	426	struct bus_type mdio_bus_type = {
	427	.name = "mdio_bus",
	428	.match = mdio_bus_match,
2f5cb434	429	.pm = MDIO_BUS_PM_OPS,
00db8189	430	};
11b0bacd	431	EXPORT_SYMBOL(mdio_bus_type);
00db8189	432
67c4f3fa	433	int __init mdio_bus_init(void)
00db8189	434	{
46abc021 LB	435	int ret;
	436
	437	ret = class_register(&mdio_bus_class);
	438	if (!ret) {
	439	ret = bus_register(&mdio_bus_type);
	440	if (ret)
	441	class_unregister(&mdio_bus_class);
	442	}
	443
	444	return ret;
00db8189 AF	445	}
00db8189 AF	446
dc85dec6	447	void mdio_bus_exit(void)
e1393456	448	{
46abc021	449	class_unregister(&mdio_bus_class);
e1393456 AF	450	bus_unregister(&mdio_bus_type);
e1393456 AF	451	}