brintos

brintos / linux-shallow public Read only

0
0
Text · 37.7 KiB · 7e2f101 Raw
1462 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/* MDIO Bus interface3 *4 * Author: Andy Fleming5 *6 * Copyright (c) 2004 Freescale Semiconductor, Inc.7 */8 9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 11#include <linux/delay.h>12#include <linux/device.h>13#include <linux/errno.h>14#include <linux/etherdevice.h>15#include <linux/ethtool.h>16#include <linux/gpio/consumer.h>17#include <linux/init.h>18#include <linux/interrupt.h>19#include <linux/io.h>20#include <linux/kernel.h>21#include <linux/micrel_phy.h>22#include <linux/mii.h>23#include <linux/mm.h>24#include <linux/module.h>25#include <linux/netdevice.h>26#include <linux/of_device.h>27#include <linux/of_mdio.h>28#include <linux/phy.h>29#include <linux/reset.h>30#include <linux/skbuff.h>31#include <linux/slab.h>32#include <linux/spinlock.h>33#include <linux/string.h>34#include <linux/uaccess.h>35#include <linux/unistd.h>36 37#define CREATE_TRACE_POINTS38#include <trace/events/mdio.h>39 40#include "mdio-boardinfo.h"41 42static int mdiobus_register_gpiod(struct mdio_device *mdiodev)43{44	/* Deassert the optional reset signal */45	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,46						 "reset", GPIOD_OUT_LOW);47	if (IS_ERR(mdiodev->reset_gpio))48		return PTR_ERR(mdiodev->reset_gpio);49 50	if (mdiodev->reset_gpio)51		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");52 53	return 0;54}55 56static int mdiobus_register_reset(struct mdio_device *mdiodev)57{58	struct reset_control *reset;59 60	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");61	if (IS_ERR(reset))62		return PTR_ERR(reset);63 64	mdiodev->reset_ctrl = reset;65 66	return 0;67}68 69int mdiobus_register_device(struct mdio_device *mdiodev)70{71	int err;72 73	if (mdiodev->bus->mdio_map[mdiodev->addr])74		return -EBUSY;75 76	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {77		err = mdiobus_register_gpiod(mdiodev);78		if (err)79			return err;80 81		err = mdiobus_register_reset(mdiodev);82		if (err)83			return err;84 85		/* Assert the reset signal */86		mdio_device_reset(mdiodev, 1);87	}88 89	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;90 91	return 0;92}93EXPORT_SYMBOL(mdiobus_register_device);94 95int mdiobus_unregister_device(struct mdio_device *mdiodev)96{97	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)98		return -EINVAL;99 100	reset_control_put(mdiodev->reset_ctrl);101 102	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;103 104	return 0;105}106EXPORT_SYMBOL(mdiobus_unregister_device);107 108static struct mdio_device *mdiobus_find_device(struct mii_bus *bus, int addr)109{110	bool addr_valid = addr >= 0 && addr < ARRAY_SIZE(bus->mdio_map);111 112	if (WARN_ONCE(!addr_valid, "addr %d out of range\n", addr))113		return NULL;114 115	return bus->mdio_map[addr];116}117 118struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)119{120	struct mdio_device *mdiodev;121 122	mdiodev = mdiobus_find_device(bus, addr);123	if (!mdiodev)124		return NULL;125 126	if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))127		return NULL;128 129	return container_of(mdiodev, struct phy_device, mdio);130}131EXPORT_SYMBOL(mdiobus_get_phy);132 133bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)134{135	return mdiobus_find_device(bus, addr) != NULL;136}137EXPORT_SYMBOL(mdiobus_is_registered_device);138 139/**140 * mdiobus_alloc_size - allocate a mii_bus structure141 * @size: extra amount of memory to allocate for private storage.142 * If non-zero, then bus->priv is points to that memory.143 *144 * Description: called by a bus driver to allocate an mii_bus145 * structure to fill in.146 */147struct mii_bus *mdiobus_alloc_size(size_t size)148{149	struct mii_bus *bus;150	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);151	size_t alloc_size;152	int i;153 154	/* If we alloc extra space, it should be aligned */155	if (size)156		alloc_size = aligned_size + size;157	else158		alloc_size = sizeof(*bus);159 160	bus = kzalloc(alloc_size, GFP_KERNEL);161	if (!bus)162		return NULL;163 164	bus->state = MDIOBUS_ALLOCATED;165	if (size)166		bus->priv = (void *)bus + aligned_size;167 168	/* Initialise the interrupts to polling and 64-bit seqcounts */169	for (i = 0; i < PHY_MAX_ADDR; i++) {170		bus->irq[i] = PHY_POLL;171		u64_stats_init(&bus->stats[i].syncp);172	}173 174	return bus;175}176EXPORT_SYMBOL(mdiobus_alloc_size);177 178/**179 * mdiobus_release - mii_bus device release callback180 * @d: the target struct device that contains the mii_bus181 *182 * Description: called when the last reference to an mii_bus is183 * dropped, to free the underlying memory.184 */185static void mdiobus_release(struct device *d)186{187	struct mii_bus *bus = to_mii_bus(d);188 189	WARN(bus->state != MDIOBUS_RELEASED &&190	     /* for compatibility with error handling in drivers */191	     bus->state != MDIOBUS_ALLOCATED,192	     "%s: not in RELEASED or ALLOCATED state\n",193	     bus->id);194 195	if (bus->state == MDIOBUS_RELEASED)196		fwnode_handle_put(dev_fwnode(d));197 198	kfree(bus);199}200 201struct mdio_bus_stat_attr {202	int addr;203	unsigned int field_offset;204};205 206static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)207{208	const char *p = (const char *)s + offset;209	unsigned int start;210	u64 val = 0;211 212	do {213		start = u64_stats_fetch_begin(&s->syncp);214		val = u64_stats_read((const u64_stats_t *)p);215	} while (u64_stats_fetch_retry(&s->syncp, start));216 217	return val;218}219 220static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)221{222	unsigned int i;223	u64 val = 0;224 225	for (i = 0; i < PHY_MAX_ADDR; i++)226		val += mdio_bus_get_stat(&bus->stats[i], offset);227 228	return val;229}230 231static ssize_t mdio_bus_stat_field_show(struct device *dev,232					struct device_attribute *attr,233					char *buf)234{235	struct mii_bus *bus = to_mii_bus(dev);236	struct mdio_bus_stat_attr *sattr;237	struct dev_ext_attribute *eattr;238	u64 val;239 240	eattr = container_of(attr, struct dev_ext_attribute, attr);241	sattr = eattr->var;242 243	if (sattr->addr < 0)244		val = mdio_bus_get_global_stat(bus, sattr->field_offset);245	else246		val = mdio_bus_get_stat(&bus->stats[sattr->addr],247					sattr->field_offset);248 249	return sysfs_emit(buf, "%llu\n", val);250}251 252static ssize_t mdio_bus_device_stat_field_show(struct device *dev,253					       struct device_attribute *attr,254					       char *buf)255{256	struct mdio_device *mdiodev = to_mdio_device(dev);257	struct mii_bus *bus = mdiodev->bus;258	struct mdio_bus_stat_attr *sattr;259	struct dev_ext_attribute *eattr;260	int addr = mdiodev->addr;261	u64 val;262 263	eattr = container_of(attr, struct dev_ext_attribute, attr);264	sattr = eattr->var;265 266	val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);267 268	return sysfs_emit(buf, "%llu\n", val);269}270 271#define MDIO_BUS_STATS_ATTR_DECL(field, file)				\272static struct dev_ext_attribute dev_attr_mdio_bus_##field = {		\273	.attr = { .attr = { .name = file, .mode = 0444 },		\274		     .show = mdio_bus_stat_field_show,			\275	},								\276	.var = &((struct mdio_bus_stat_attr) {				\277		-1, offsetof(struct mdio_bus_stats, field)		\278	}),								\279};									\280static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = {	\281	.attr = { .attr = { .name = file, .mode = 0444 },		\282		     .show = mdio_bus_device_stat_field_show,		\283	},								\284	.var = &((struct mdio_bus_stat_attr) {				\285		-1, offsetof(struct mdio_bus_stats, field)		\286	}),								\287};288 289#define MDIO_BUS_STATS_ATTR(field)					\290	MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))291 292MDIO_BUS_STATS_ATTR(transfers);293MDIO_BUS_STATS_ATTR(errors);294MDIO_BUS_STATS_ATTR(writes);295MDIO_BUS_STATS_ATTR(reads);296 297#define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file)		\298static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \299	.attr = { .attr = { .name = file, .mode = 0444 },		\300		     .show = mdio_bus_stat_field_show,			\301	},								\302	.var = &((struct mdio_bus_stat_attr) {				\303		addr, offsetof(struct mdio_bus_stats, field)		\304	}),								\305}306 307#define MDIO_BUS_STATS_ADDR_ATTR(field, addr)				\308	MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr,			\309				 __stringify(field) "_" __stringify(addr))310 311#define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr)			\312	MDIO_BUS_STATS_ADDR_ATTR(transfers, addr);			\313	MDIO_BUS_STATS_ADDR_ATTR(errors, addr);				\314	MDIO_BUS_STATS_ADDR_ATTR(writes, addr);				\315	MDIO_BUS_STATS_ADDR_ATTR(reads, addr)				\316 317MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);318MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);319MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);320MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);321MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);322MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);323MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);324MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);325MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);326MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);327MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);328MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);329MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);330MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);331MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);332MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);333MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);334MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);335MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);336MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);337MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);338MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);339MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);340MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);341MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);342MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);343MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);344MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);345MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);346MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);347MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);348MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);349 350#define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr)				\351	&dev_attr_mdio_bus_addr_transfers_##addr.attr.attr,		\352	&dev_attr_mdio_bus_addr_errors_##addr.attr.attr,		\353	&dev_attr_mdio_bus_addr_writes_##addr.attr.attr,		\354	&dev_attr_mdio_bus_addr_reads_##addr.attr.attr			\355 356static struct attribute *mdio_bus_statistics_attrs[] = {357	&dev_attr_mdio_bus_transfers.attr.attr,358	&dev_attr_mdio_bus_errors.attr.attr,359	&dev_attr_mdio_bus_writes.attr.attr,360	&dev_attr_mdio_bus_reads.attr.attr,361	MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),362	MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),363	MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),364	MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),365	MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),366	MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),367	MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),368	MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),369	MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),370	MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),371	MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),372	MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),373	MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),374	MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),375	MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),376	MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),377	MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),378	MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),379	MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),380	MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),381	MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),382	MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),383	MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),384	MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),385	MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),386	MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),387	MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),388	MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),389	MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),390	MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),391	MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),392	MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),393	NULL,394};395 396static const struct attribute_group mdio_bus_statistics_group = {397	.name	= "statistics",398	.attrs	= mdio_bus_statistics_attrs,399};400 401static const struct attribute_group *mdio_bus_groups[] = {402	&mdio_bus_statistics_group,403	NULL,404};405 406static struct class mdio_bus_class = {407	.name		= "mdio_bus",408	.dev_release	= mdiobus_release,409	.dev_groups	= mdio_bus_groups,410};411 412/**413 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.414 * @mdio_name: The name of a mdiobus.415 *416 * Returns a reference to the mii_bus, or NULL if none found.  The417 * embedded struct device will have its reference count incremented,418 * and this must be put_deviced'ed once the bus is finished with.419 */420struct mii_bus *mdio_find_bus(const char *mdio_name)421{422	struct device *d;423 424	d = class_find_device_by_name(&mdio_bus_class, mdio_name);425	return d ? to_mii_bus(d) : NULL;426}427EXPORT_SYMBOL(mdio_find_bus);428 429#if IS_ENABLED(CONFIG_OF_MDIO)430/**431 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.432 * @mdio_bus_np: Pointer to the mii_bus.433 *434 * Returns a reference to the mii_bus, or NULL if none found.  The435 * embedded struct device will have its reference count incremented,436 * and this must be put once the bus is finished with.437 *438 * Because the association of a device_node and mii_bus is made via439 * of_mdiobus_register(), the mii_bus cannot be found before it is440 * registered with of_mdiobus_register().441 *442 */443struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)444{445	struct device *d;446 447	if (!mdio_bus_np)448		return NULL;449 450	d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);451	return d ? to_mii_bus(d) : NULL;452}453EXPORT_SYMBOL(of_mdio_find_bus);454 455/* Walk the list of subnodes of a mdio bus and look for a node that456 * matches the mdio device's address with its 'reg' property. If457 * found, set the of_node pointer for the mdio device. This allows458 * auto-probed phy devices to be supplied with information passed in459 * via DT.460 * If a PHY package is found, PHY is searched also there.461 */462static int of_mdiobus_find_phy(struct device *dev, struct mdio_device *mdiodev,463			       struct device_node *np)464{465	struct device_node *child;466 467	for_each_available_child_of_node(np, child) {468		int addr;469 470		if (of_node_name_eq(child, "ethernet-phy-package")) {471			/* Validate PHY package reg presence */472			if (!of_property_present(child, "reg")) {473				of_node_put(child);474				return -EINVAL;475			}476 477			if (!of_mdiobus_find_phy(dev, mdiodev, child)) {478				/* The refcount for the PHY package will be479				 * incremented later when PHY join the Package.480				 */481				of_node_put(child);482				return 0;483			}484 485			continue;486		}487 488		addr = of_mdio_parse_addr(dev, child);489		if (addr < 0)490			continue;491 492		if (addr == mdiodev->addr) {493			device_set_node(dev, of_fwnode_handle(child));494			/* The refcount on "child" is passed to the mdio495			 * device. Do _not_ use of_node_put(child) here.496			 */497			return 0;498		}499	}500 501	return -ENODEV;502}503 504static void of_mdiobus_link_mdiodev(struct mii_bus *bus,505				    struct mdio_device *mdiodev)506{507	struct device *dev = &mdiodev->dev;508 509	if (dev->of_node || !bus->dev.of_node)510		return;511 512	of_mdiobus_find_phy(dev, mdiodev, bus->dev.of_node);513}514#else /* !IS_ENABLED(CONFIG_OF_MDIO) */515static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,516					   struct mdio_device *mdiodev)517{518}519#endif520 521/**522 * mdiobus_create_device - create a full MDIO device given523 * a mdio_board_info structure524 * @bus: MDIO bus to create the devices on525 * @bi: mdio_board_info structure describing the devices526 *527 * Returns 0 on success or < 0 on error.528 */529static int mdiobus_create_device(struct mii_bus *bus,530				 struct mdio_board_info *bi)531{532	struct mdio_device *mdiodev;533	int ret = 0;534 535	mdiodev = mdio_device_create(bus, bi->mdio_addr);536	if (IS_ERR(mdiodev))537		return -ENODEV;538 539	strscpy(mdiodev->modalias, bi->modalias,540		sizeof(mdiodev->modalias));541	mdiodev->bus_match = mdio_device_bus_match;542	mdiodev->dev.platform_data = (void *)bi->platform_data;543 544	ret = mdio_device_register(mdiodev);545	if (ret)546		mdio_device_free(mdiodev);547 548	return ret;549}550 551static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)552{553	struct phy_device *phydev = ERR_PTR(-ENODEV);554	int err;555 556	phydev = get_phy_device(bus, addr, c45);557	if (IS_ERR(phydev))558		return phydev;559 560	/* For DT, see if the auto-probed phy has a corresponding child561	 * in the bus node, and set the of_node pointer in this case.562	 */563	of_mdiobus_link_mdiodev(bus, &phydev->mdio);564 565	err = phy_device_register(phydev);566	if (err) {567		phy_device_free(phydev);568		return ERR_PTR(-ENODEV);569	}570 571	return phydev;572}573 574/**575 * mdiobus_scan_c22 - scan one address on a bus for C22 MDIO devices.576 * @bus: mii_bus to scan577 * @addr: address on bus to scan578 *579 * This function scans one address on the MDIO bus, looking for580 * devices which can be identified using a vendor/product ID in581 * registers 2 and 3. Not all MDIO devices have such registers, but582 * PHY devices typically do. Hence this function assumes anything583 * found is a PHY, or can be treated as a PHY. Other MDIO devices,584 * such as switches, will probably not be found during the scan.585 */586struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr)587{588	return mdiobus_scan(bus, addr, false);589}590EXPORT_SYMBOL(mdiobus_scan_c22);591 592/**593 * mdiobus_scan_c45 - scan one address on a bus for C45 MDIO devices.594 * @bus: mii_bus to scan595 * @addr: address on bus to scan596 *597 * This function scans one address on the MDIO bus, looking for598 * devices which can be identified using a vendor/product ID in599 * registers 2 and 3. Not all MDIO devices have such registers, but600 * PHY devices typically do. Hence this function assumes anything601 * found is a PHY, or can be treated as a PHY. Other MDIO devices,602 * such as switches, will probably not be found during the scan.603 */604static struct phy_device *mdiobus_scan_c45(struct mii_bus *bus, int addr)605{606	return mdiobus_scan(bus, addr, true);607}608 609static int mdiobus_scan_bus_c22(struct mii_bus *bus)610{611	int i;612 613	for (i = 0; i < PHY_MAX_ADDR; i++) {614		if ((bus->phy_mask & BIT(i)) == 0) {615			struct phy_device *phydev;616 617			phydev = mdiobus_scan_c22(bus, i);618			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))619				return PTR_ERR(phydev);620		}621	}622	return 0;623}624 625static int mdiobus_scan_bus_c45(struct mii_bus *bus)626{627	int i;628 629	for (i = 0; i < PHY_MAX_ADDR; i++) {630		if ((bus->phy_mask & BIT(i)) == 0) {631			struct phy_device *phydev;632 633			/* Don't scan C45 if we already have a C22 device */634			if (bus->mdio_map[i])635				continue;636 637			phydev = mdiobus_scan_c45(bus, i);638			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))639				return PTR_ERR(phydev);640		}641	}642	return 0;643}644 645/* There are some C22 PHYs which do bad things when where is a C45646 * transaction on the bus, like accepting a read themselves, and647 * stomping over the true devices reply, to performing a write to648 * themselves which was intended for another device. Now that C22649 * devices have been found, see if any of them are bad for C45, and if we650 * should skip the C45 scan.651 */652static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)653{654	int i;655 656	for (i = 0; i < PHY_MAX_ADDR; i++) {657		struct phy_device *phydev;658		u32 oui;659 660		phydev = mdiobus_get_phy(bus, i);661		if (!phydev)662			continue;663		oui = phydev->phy_id >> 10;664 665		if (oui == MICREL_OUI)666			return true;667	}668	return false;669}670 671/**672 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus673 * @bus: target mii_bus674 * @owner: module containing bus accessor functions675 *676 * Description: Called by a bus driver to bring up all the PHYs677 *   on a given bus, and attach them to the bus. Drivers should use678 *   mdiobus_register() rather than __mdiobus_register() unless they679 *   need to pass a specific owner module. MDIO devices which are not680 *   PHYs will not be brought up by this function. They are expected681 *   to be explicitly listed in DT and instantiated by of_mdiobus_register().682 *683 * Returns 0 on success or < 0 on error.684 */685int __mdiobus_register(struct mii_bus *bus, struct module *owner)686{687	struct mdio_device *mdiodev;688	struct gpio_desc *gpiod;689	bool prevent_c45_scan;690	int i, err;691 692	if (!bus || !bus->name)693		return -EINVAL;694 695	/* An access method always needs both read and write operations */696	if (!!bus->read != !!bus->write || !!bus->read_c45 != !!bus->write_c45)697		return -EINVAL;698 699	/* At least one method is mandatory */700	if (!bus->read && !bus->read_c45)701		return -EINVAL;702 703	if (bus->parent && bus->parent->of_node)704		bus->parent->of_node->fwnode.flags |=705					FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;706 707	WARN(bus->state != MDIOBUS_ALLOCATED &&708	     bus->state != MDIOBUS_UNREGISTERED,709	     "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);710 711	bus->owner = owner;712	bus->dev.parent = bus->parent;713	bus->dev.class = &mdio_bus_class;714	bus->dev.groups = NULL;715	dev_set_name(&bus->dev, "%s", bus->id);716 717	/* If the bus state is allocated, we're registering a fresh bus718	 * that may have a fwnode associated with it. Grab a reference719	 * to the fwnode. This will be dropped when the bus is released.720	 * If the bus was set to unregistered, it means that the bus was721	 * previously registered, and we've already grabbed a reference.722	 */723	if (bus->state == MDIOBUS_ALLOCATED)724		fwnode_handle_get(dev_fwnode(&bus->dev));725 726	/* We need to set state to MDIOBUS_UNREGISTERED to correctly release727	 * the device in mdiobus_free()728	 *729	 * State will be updated later in this function in case of success730	 */731	bus->state = MDIOBUS_UNREGISTERED;732 733	err = device_register(&bus->dev);734	if (err) {735		pr_err("mii_bus %s failed to register\n", bus->id);736		return -EINVAL;737	}738 739	mutex_init(&bus->mdio_lock);740	mutex_init(&bus->shared_lock);741 742	/* assert bus level PHY GPIO reset */743	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);744	if (IS_ERR(gpiod)) {745		err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),746				    "mii_bus %s couldn't get reset GPIO\n",747				    bus->id);748		device_del(&bus->dev);749		return err;750	} else	if (gpiod) {751		bus->reset_gpiod = gpiod;752		fsleep(bus->reset_delay_us);753		gpiod_set_value_cansleep(gpiod, 0);754		if (bus->reset_post_delay_us > 0)755			fsleep(bus->reset_post_delay_us);756	}757 758	if (bus->reset) {759		err = bus->reset(bus);760		if (err)761			goto error_reset_gpiod;762	}763 764	if (bus->read) {765		err = mdiobus_scan_bus_c22(bus);766		if (err)767			goto error;768	}769 770	prevent_c45_scan = mdiobus_prevent_c45_scan(bus);771 772	if (!prevent_c45_scan && bus->read_c45) {773		err = mdiobus_scan_bus_c45(bus);774		if (err)775			goto error;776	}777 778	mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);779 780	bus->state = MDIOBUS_REGISTERED;781	dev_dbg(&bus->dev, "probed\n");782	return 0;783 784error:785	for (i = 0; i < PHY_MAX_ADDR; i++) {786		mdiodev = bus->mdio_map[i];787		if (!mdiodev)788			continue;789 790		mdiodev->device_remove(mdiodev);791		mdiodev->device_free(mdiodev);792	}793error_reset_gpiod:794	/* Put PHYs in RESET to save power */795	if (bus->reset_gpiod)796		gpiod_set_value_cansleep(bus->reset_gpiod, 1);797 798	device_del(&bus->dev);799	return err;800}801EXPORT_SYMBOL(__mdiobus_register);802 803void mdiobus_unregister(struct mii_bus *bus)804{805	struct mdio_device *mdiodev;806	int i;807 808	if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))809		return;810	bus->state = MDIOBUS_UNREGISTERED;811 812	for (i = 0; i < PHY_MAX_ADDR; i++) {813		mdiodev = bus->mdio_map[i];814		if (!mdiodev)815			continue;816 817		if (mdiodev->reset_gpio)818			gpiod_put(mdiodev->reset_gpio);819 820		mdiodev->device_remove(mdiodev);821		mdiodev->device_free(mdiodev);822	}823 824	/* Put PHYs in RESET to save power */825	if (bus->reset_gpiod)826		gpiod_set_value_cansleep(bus->reset_gpiod, 1);827 828	device_del(&bus->dev);829}830EXPORT_SYMBOL(mdiobus_unregister);831 832/**833 * mdiobus_free - free a struct mii_bus834 * @bus: mii_bus to free835 *836 * This function releases the reference to the underlying device837 * object in the mii_bus.  If this is the last reference, the mii_bus838 * will be freed.839 */840void mdiobus_free(struct mii_bus *bus)841{842	/* For compatibility with error handling in drivers. */843	if (bus->state == MDIOBUS_ALLOCATED) {844		kfree(bus);845		return;846	}847 848	WARN(bus->state != MDIOBUS_UNREGISTERED,849	     "%s: not in UNREGISTERED state\n", bus->id);850	bus->state = MDIOBUS_RELEASED;851 852	put_device(&bus->dev);853}854EXPORT_SYMBOL(mdiobus_free);855 856static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)857{858	preempt_disable();859	u64_stats_update_begin(&stats->syncp);860 861	u64_stats_inc(&stats->transfers);862	if (ret < 0) {863		u64_stats_inc(&stats->errors);864		goto out;865	}866 867	if (op)868		u64_stats_inc(&stats->reads);869	else870		u64_stats_inc(&stats->writes);871out:872	u64_stats_update_end(&stats->syncp);873	preempt_enable();874}875 876/**877 * __mdiobus_read - Unlocked version of the mdiobus_read function878 * @bus: the mii_bus struct879 * @addr: the phy address880 * @regnum: register number to read881 *882 * Read a MDIO bus register. Caller must hold the mdio bus lock.883 *884 * NOTE: MUST NOT be called from interrupt context.885 */886int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)887{888	int retval;889 890	lockdep_assert_held_once(&bus->mdio_lock);891 892	if (bus->read)893		retval = bus->read(bus, addr, regnum);894	else895		retval = -EOPNOTSUPP;896 897	trace_mdio_access(bus, 1, addr, regnum, retval, retval);898	mdiobus_stats_acct(&bus->stats[addr], true, retval);899 900	return retval;901}902EXPORT_SYMBOL(__mdiobus_read);903 904/**905 * __mdiobus_write - Unlocked version of the mdiobus_write function906 * @bus: the mii_bus struct907 * @addr: the phy address908 * @regnum: register number to write909 * @val: value to write to @regnum910 *911 * Write a MDIO bus register. Caller must hold the mdio bus lock.912 *913 * NOTE: MUST NOT be called from interrupt context.914 */915int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)916{917	int err;918 919	lockdep_assert_held_once(&bus->mdio_lock);920 921	if (bus->write)922		err = bus->write(bus, addr, regnum, val);923	else924		err = -EOPNOTSUPP;925 926	trace_mdio_access(bus, 0, addr, regnum, val, err);927	mdiobus_stats_acct(&bus->stats[addr], false, err);928 929	return err;930}931EXPORT_SYMBOL(__mdiobus_write);932 933/**934 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function935 * @bus: the mii_bus struct936 * @addr: the phy address937 * @regnum: register number to modify938 * @mask: bit mask of bits to clear939 * @set: bit mask of bits to set940 *941 * Read, modify, and if any change, write the register value back to the942 * device. Any error returns a negative number.943 *944 * NOTE: MUST NOT be called from interrupt context.945 */946int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,947			     u16 mask, u16 set)948{949	int new, ret;950 951	ret = __mdiobus_read(bus, addr, regnum);952	if (ret < 0)953		return ret;954 955	new = (ret & ~mask) | set;956	if (new == ret)957		return 0;958 959	ret = __mdiobus_write(bus, addr, regnum, new);960 961	return ret < 0 ? ret : 1;962}963EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);964 965/**966 * __mdiobus_c45_read - Unlocked version of the mdiobus_c45_read function967 * @bus: the mii_bus struct968 * @addr: the phy address969 * @devad: device address to read970 * @regnum: register number to read971 *972 * Read a MDIO bus register. Caller must hold the mdio bus lock.973 *974 * NOTE: MUST NOT be called from interrupt context.975 */976int __mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)977{978	int retval;979 980	lockdep_assert_held_once(&bus->mdio_lock);981 982	if (bus->read_c45)983		retval = bus->read_c45(bus, addr, devad, regnum);984	else985		retval = -EOPNOTSUPP;986 987	trace_mdio_access(bus, 1, addr, regnum, retval, retval);988	mdiobus_stats_acct(&bus->stats[addr], true, retval);989 990	return retval;991}992EXPORT_SYMBOL(__mdiobus_c45_read);993 994/**995 * __mdiobus_c45_write - Unlocked version of the mdiobus_write function996 * @bus: the mii_bus struct997 * @addr: the phy address998 * @devad: device address to read999 * @regnum: register number to write1000 * @val: value to write to @regnum1001 *1002 * Write a MDIO bus register. Caller must hold the mdio bus lock.1003 *1004 * NOTE: MUST NOT be called from interrupt context.1005 */1006int __mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,1007			u16 val)1008{1009	int err;1010 1011	lockdep_assert_held_once(&bus->mdio_lock);1012 1013	if (bus->write_c45)1014		err = bus->write_c45(bus, addr, devad, regnum, val);1015	else1016		err = -EOPNOTSUPP;1017 1018	trace_mdio_access(bus, 0, addr, regnum, val, err);1019	mdiobus_stats_acct(&bus->stats[addr], false, err);1020 1021	return err;1022}1023EXPORT_SYMBOL(__mdiobus_c45_write);1024 1025/**1026 * __mdiobus_c45_modify_changed - Unlocked version of the mdiobus_modify function1027 * @bus: the mii_bus struct1028 * @addr: the phy address1029 * @devad: device address to read1030 * @regnum: register number to modify1031 * @mask: bit mask of bits to clear1032 * @set: bit mask of bits to set1033 *1034 * Read, modify, and if any change, write the register value back to the1035 * device. Any error returns a negative number.1036 *1037 * NOTE: MUST NOT be called from interrupt context.1038 */1039static int __mdiobus_c45_modify_changed(struct mii_bus *bus, int addr,1040					int devad, u32 regnum, u16 mask,1041					u16 set)1042{1043	int new, ret;1044 1045	ret = __mdiobus_c45_read(bus, addr, devad, regnum);1046	if (ret < 0)1047		return ret;1048 1049	new = (ret & ~mask) | set;1050	if (new == ret)1051		return 0;1052 1053	ret = __mdiobus_c45_write(bus, addr, devad, regnum, new);1054 1055	return ret < 0 ? ret : 1;1056}1057 1058/**1059 * mdiobus_read_nested - Nested version of the mdiobus_read function1060 * @bus: the mii_bus struct1061 * @addr: the phy address1062 * @regnum: register number to read1063 *1064 * In case of nested MDIO bus access avoid lockdep false positives by1065 * using mutex_lock_nested().1066 *1067 * NOTE: MUST NOT be called from interrupt context,1068 * because the bus read/write functions may wait for an interrupt1069 * to conclude the operation.1070 */1071int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)1072{1073	int retval;1074 1075	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);1076	retval = __mdiobus_read(bus, addr, regnum);1077	mutex_unlock(&bus->mdio_lock);1078 1079	return retval;1080}1081EXPORT_SYMBOL(mdiobus_read_nested);1082 1083/**1084 * mdiobus_read - Convenience function for reading a given MII mgmt register1085 * @bus: the mii_bus struct1086 * @addr: the phy address1087 * @regnum: register number to read1088 *1089 * NOTE: MUST NOT be called from interrupt context,1090 * because the bus read/write functions may wait for an interrupt1091 * to conclude the operation.1092 */1093int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)1094{1095	int retval;1096 1097	mutex_lock(&bus->mdio_lock);1098	retval = __mdiobus_read(bus, addr, regnum);1099	mutex_unlock(&bus->mdio_lock);1100 1101	return retval;1102}1103EXPORT_SYMBOL(mdiobus_read);1104 1105/**1106 * mdiobus_c45_read - Convenience function for reading a given MII mgmt register1107 * @bus: the mii_bus struct1108 * @addr: the phy address1109 * @devad: device address to read1110 * @regnum: register number to read1111 *1112 * NOTE: MUST NOT be called from interrupt context,1113 * because the bus read/write functions may wait for an interrupt1114 * to conclude the operation.1115 */1116int mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)1117{1118	int retval;1119 1120	mutex_lock(&bus->mdio_lock);1121	retval = __mdiobus_c45_read(bus, addr, devad, regnum);1122	mutex_unlock(&bus->mdio_lock);1123 1124	return retval;1125}1126EXPORT_SYMBOL(mdiobus_c45_read);1127 1128/**1129 * mdiobus_c45_read_nested - Nested version of the mdiobus_c45_read function1130 * @bus: the mii_bus struct1131 * @addr: the phy address1132 * @devad: device address to read1133 * @regnum: register number to read1134 *1135 * In case of nested MDIO bus access avoid lockdep false positives by1136 * using mutex_lock_nested().1137 *1138 * NOTE: MUST NOT be called from interrupt context,1139 * because the bus read/write functions may wait for an interrupt1140 * to conclude the operation.1141 */1142int mdiobus_c45_read_nested(struct mii_bus *bus, int addr, int devad,1143			    u32 regnum)1144{1145	int retval;1146 1147	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);1148	retval = __mdiobus_c45_read(bus, addr, devad, regnum);1149	mutex_unlock(&bus->mdio_lock);1150 1151	return retval;1152}1153EXPORT_SYMBOL(mdiobus_c45_read_nested);1154 1155/**1156 * mdiobus_write_nested - Nested version of the mdiobus_write function1157 * @bus: the mii_bus struct1158 * @addr: the phy address1159 * @regnum: register number to write1160 * @val: value to write to @regnum1161 *1162 * In case of nested MDIO bus access avoid lockdep false positives by1163 * using mutex_lock_nested().1164 *1165 * NOTE: MUST NOT be called from interrupt context,1166 * because the bus read/write functions may wait for an interrupt1167 * to conclude the operation.1168 */1169int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)1170{1171	int err;1172 1173	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);1174	err = __mdiobus_write(bus, addr, regnum, val);1175	mutex_unlock(&bus->mdio_lock);1176 1177	return err;1178}1179EXPORT_SYMBOL(mdiobus_write_nested);1180 1181/**1182 * mdiobus_write - Convenience function for writing a given MII mgmt register1183 * @bus: the mii_bus struct1184 * @addr: the phy address1185 * @regnum: register number to write1186 * @val: value to write to @regnum1187 *1188 * NOTE: MUST NOT be called from interrupt context,1189 * because the bus read/write functions may wait for an interrupt1190 * to conclude the operation.1191 */1192int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)1193{1194	int err;1195 1196	mutex_lock(&bus->mdio_lock);1197	err = __mdiobus_write(bus, addr, regnum, val);1198	mutex_unlock(&bus->mdio_lock);1199 1200	return err;1201}1202EXPORT_SYMBOL(mdiobus_write);1203 1204/**1205 * mdiobus_c45_write - Convenience function for writing a given MII mgmt register1206 * @bus: the mii_bus struct1207 * @addr: the phy address1208 * @devad: device address to read1209 * @regnum: register number to write1210 * @val: value to write to @regnum1211 *1212 * NOTE: MUST NOT be called from interrupt context,1213 * because the bus read/write functions may wait for an interrupt1214 * to conclude the operation.1215 */1216int mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,1217		      u16 val)1218{1219	int err;1220 1221	mutex_lock(&bus->mdio_lock);1222	err = __mdiobus_c45_write(bus, addr, devad, regnum, val);1223	mutex_unlock(&bus->mdio_lock);1224 1225	return err;1226}1227EXPORT_SYMBOL(mdiobus_c45_write);1228 1229/**1230 * mdiobus_c45_write_nested - Nested version of the mdiobus_c45_write function1231 * @bus: the mii_bus struct1232 * @addr: the phy address1233 * @devad: device address to read1234 * @regnum: register number to write1235 * @val: value to write to @regnum1236 *1237 * In case of nested MDIO bus access avoid lockdep false positives by1238 * using mutex_lock_nested().1239 *1240 * NOTE: MUST NOT be called from interrupt context,1241 * because the bus read/write functions may wait for an interrupt1242 * to conclude the operation.1243 */1244int mdiobus_c45_write_nested(struct mii_bus *bus, int addr, int devad,1245			     u32 regnum, u16 val)1246{1247	int err;1248 1249	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);1250	err = __mdiobus_c45_write(bus, addr, devad, regnum, val);1251	mutex_unlock(&bus->mdio_lock);1252 1253	return err;1254}1255EXPORT_SYMBOL(mdiobus_c45_write_nested);1256 1257/*1258 * __mdiobus_modify - Convenience function for modifying a given mdio device1259 *	register1260 * @bus: the mii_bus struct1261 * @addr: the phy address1262 * @regnum: register number to write1263 * @mask: bit mask of bits to clear1264 * @set: bit mask of bits to set1265 */1266int __mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask,1267		     u16 set)1268{1269	int err;1270 1271	err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);1272 1273	return err < 0 ? err : 0;1274}1275EXPORT_SYMBOL_GPL(__mdiobus_modify);1276 1277/**1278 * mdiobus_modify - Convenience function for modifying a given mdio device1279 *	register1280 * @bus: the mii_bus struct1281 * @addr: the phy address1282 * @regnum: register number to write1283 * @mask: bit mask of bits to clear1284 * @set: bit mask of bits to set1285 */1286int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)1287{1288	int err;1289 1290	mutex_lock(&bus->mdio_lock);1291	err = __mdiobus_modify(bus, addr, regnum, mask, set);1292	mutex_unlock(&bus->mdio_lock);1293 1294	return err;1295}1296EXPORT_SYMBOL_GPL(mdiobus_modify);1297 1298/**1299 * mdiobus_c45_modify - Convenience function for modifying a given mdio device1300 *	register1301 * @bus: the mii_bus struct1302 * @addr: the phy address1303 * @devad: device address to read1304 * @regnum: register number to write1305 * @mask: bit mask of bits to clear1306 * @set: bit mask of bits to set1307 */1308int mdiobus_c45_modify(struct mii_bus *bus, int addr, int devad, u32 regnum,1309		       u16 mask, u16 set)1310{1311	int err;1312 1313	mutex_lock(&bus->mdio_lock);1314	err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum,1315					   mask, set);1316	mutex_unlock(&bus->mdio_lock);1317 1318	return err < 0 ? err : 0;1319}1320EXPORT_SYMBOL_GPL(mdiobus_c45_modify);1321 1322/**1323 * mdiobus_modify_changed - Convenience function for modifying a given mdio1324 *	device register and returning if it changed1325 * @bus: the mii_bus struct1326 * @addr: the phy address1327 * @regnum: register number to write1328 * @mask: bit mask of bits to clear1329 * @set: bit mask of bits to set1330 */1331int mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,1332			   u16 mask, u16 set)1333{1334	int err;1335 1336	mutex_lock(&bus->mdio_lock);1337	err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);1338	mutex_unlock(&bus->mdio_lock);1339 1340	return err;1341}1342EXPORT_SYMBOL_GPL(mdiobus_modify_changed);1343 1344/**1345 * mdiobus_c45_modify_changed - Convenience function for modifying a given mdio1346 *	device register and returning if it changed1347 * @bus: the mii_bus struct1348 * @addr: the phy address1349 * @devad: device address to read1350 * @regnum: register number to write1351 * @mask: bit mask of bits to clear1352 * @set: bit mask of bits to set1353 */1354int mdiobus_c45_modify_changed(struct mii_bus *bus, int addr, int devad,1355			       u32 regnum, u16 mask, u16 set)1356{1357	int err;1358 1359	mutex_lock(&bus->mdio_lock);1360	err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum, mask, set);1361	mutex_unlock(&bus->mdio_lock);1362 1363	return err;1364}1365EXPORT_SYMBOL_GPL(mdiobus_c45_modify_changed);1366 1367/**1368 * mdio_bus_match - determine if given MDIO driver supports the given1369 *		    MDIO device1370 * @dev: target MDIO device1371 * @drv: given MDIO driver1372 *1373 * Description: Given a MDIO device, and a MDIO driver, return 1 if1374 *   the driver supports the device.  Otherwise, return 0. This may1375 *   require calling the devices own match function, since different classes1376 *   of MDIO devices have different match criteria.1377 */1378static int mdio_bus_match(struct device *dev, const struct device_driver *drv)1379{1380	const struct mdio_driver *mdiodrv = to_mdio_driver(drv);1381	struct mdio_device *mdio = to_mdio_device(dev);1382 1383	/* Both the driver and device must type-match */1384	if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=1385	    !(mdio->flags & MDIO_DEVICE_FLAG_PHY))1386		return 0;1387 1388	if (of_driver_match_device(dev, drv))1389		return 1;1390 1391	if (mdio->bus_match)1392		return mdio->bus_match(dev, drv);1393 1394	return 0;1395}1396 1397static int mdio_uevent(const struct device *dev, struct kobj_uevent_env *env)1398{1399	int rc;1400 1401	/* Some devices have extra OF data and an OF-style MODALIAS */1402	rc = of_device_uevent_modalias(dev, env);1403	if (rc != -ENODEV)1404		return rc;1405 1406	return 0;1407}1408 1409static struct attribute *mdio_bus_device_statistics_attrs[] = {1410	&dev_attr_mdio_bus_device_transfers.attr.attr,1411	&dev_attr_mdio_bus_device_errors.attr.attr,1412	&dev_attr_mdio_bus_device_writes.attr.attr,1413	&dev_attr_mdio_bus_device_reads.attr.attr,1414	NULL,1415};1416 1417static const struct attribute_group mdio_bus_device_statistics_group = {1418	.name	= "statistics",1419	.attrs	= mdio_bus_device_statistics_attrs,1420};1421 1422static const struct attribute_group *mdio_bus_dev_groups[] = {1423	&mdio_bus_device_statistics_group,1424	NULL,1425};1426 1427const struct bus_type mdio_bus_type = {1428	.name		= "mdio_bus",1429	.dev_groups	= mdio_bus_dev_groups,1430	.match		= mdio_bus_match,1431	.uevent		= mdio_uevent,1432};1433EXPORT_SYMBOL(mdio_bus_type);1434 1435int __init mdio_bus_init(void)1436{1437	int ret;1438 1439	ret = class_register(&mdio_bus_class);1440	if (!ret) {1441		ret = bus_register(&mdio_bus_type);1442		if (ret)1443			class_unregister(&mdio_bus_class);1444	}1445 1446	return ret;1447}1448 1449#if IS_ENABLED(CONFIG_PHYLIB)1450void mdio_bus_exit(void)1451{1452	class_unregister(&mdio_bus_class);1453	bus_unregister(&mdio_bus_type);1454}1455EXPORT_SYMBOL_GPL(mdio_bus_exit);1456#else1457module_init(mdio_bus_init);1458/* no module_exit, intentional */1459MODULE_LICENSE("GPL");1460MODULE_DESCRIPTION("MDIO bus/device layer");1461#endif1462