1// SPDX-License-Identifier: GPL-2.0+
2/* MDIO Bus interface
3 *
4 * Author: Andy Fleming
5 *
6 * Copyright (c) 2004 Freescale Semiconductor, Inc.
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
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_POINTS
38#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 structure
141 * @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_bus
145 * 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	else
158		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 callback
180 * @d: the target struct device that contains the mii_bus
181 *
182 * Description: called when the last reference to an mii_bus is
183 * 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	else
246		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.  The
417 * 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.  The
435 * 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 via
439 * of_mdiobus_register(), the mii_bus cannot be found before it is
440 * 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 that
456 * matches the mdio device's address with its 'reg' property. If
457 * found, set the of_node pointer for the mdio device. This allows
458 * auto-probed phy devices to be supplied with information passed in
459 * 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 be
479				 * 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 mdio
495			 * 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#endif
520
521/**
522 * mdiobus_create_device - create a full MDIO device given
523 * a mdio_board_info structure
524 * @bus: MDIO bus to create the devices on
525 * @bi: mdio_board_info structure describing the devices
526 *
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 child
561	 * 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 scan
577 * @addr: address on bus to scan
578 *
579 * This function scans one address on the MDIO bus, looking for
580 * devices which can be identified using a vendor/product ID in
581 * registers 2 and 3. Not all MDIO devices have such registers, but
582 * PHY devices typically do. Hence this function assumes anything
583 * 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 scan
595 * @addr: address on bus to scan
596 *
597 * This function scans one address on the MDIO bus, looking for
598 * devices which can be identified using a vendor/product ID in
599 * registers 2 and 3. Not all MDIO devices have such registers, but
600 * PHY devices typically do. Hence this function assumes anything
601 * 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 C45
646 * transaction on the bus, like accepting a read themselves, and
647 * stomping over the true devices reply, to performing a write to
648 * themselves which was intended for another device. Now that C22
649 * devices have been found, see if any of them are bad for C45, and if we
650 * 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 bus
673 * @bus: target mii_bus
674 * @owner: module containing bus accessor functions
675 *
676 * Description: Called by a bus driver to bring up all the PHYs
677 *   on a given bus, and attach them to the bus. Drivers should use
678 *   mdiobus_register() rather than __mdiobus_register() unless they
679 *   need to pass a specific owner module. MDIO devices which are not
680 *   PHYs will not be brought up by this function. They are expected
681 *   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 bus
718	 * that may have a fwnode associated with it. Grab a reference
719	 * 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 was
721	 * 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 release
727	 * the device in mdiobus_free()
728	 *
729	 * State will be updated later in this function in case of success
730	 */
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_bus
834 * @bus: mii_bus to free
835 *
836 * This function releases the reference to the underlying device
837 * object in the mii_bus.  If this is the last reference, the mii_bus
838 * 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	else
870		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 function
878 * @bus: the mii_bus struct
879 * @addr: the phy address
880 * @regnum: register number to read
881 *
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	else
895		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 function
906 * @bus: the mii_bus struct
907 * @addr: the phy address
908 * @regnum: register number to write
909 * @val: value to write to @regnum
910 *
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	else
924		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 function
935 * @bus: the mii_bus struct
936 * @addr: the phy address
937 * @regnum: register number to modify
938 * @mask: bit mask of bits to clear
939 * @set: bit mask of bits to set
940 *
941 * Read, modify, and if any change, write the register value back to the
942 * 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 function
967 * @bus: the mii_bus struct
968 * @addr: the phy address
969 * @devad: device address to read
970 * @regnum: register number to read
971 *
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	else
985		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 function
996 * @bus: the mii_bus struct
997 * @addr: the phy address
998 * @devad: device address to read
999 * @regnum: register number to write
1000 * @val: value to write to @regnum
1001 *
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	else
1016		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 function
1027 * @bus: the mii_bus struct
1028 * @addr: the phy address
1029 * @devad: device address to read
1030 * @regnum: register number to modify
1031 * @mask: bit mask of bits to clear
1032 * @set: bit mask of bits to set
1033 *
1034 * Read, modify, and if any change, write the register value back to the
1035 * 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 function
1060 * @bus: the mii_bus struct
1061 * @addr: the phy address
1062 * @regnum: register number to read
1063 *
1064 * In case of nested MDIO bus access avoid lockdep false positives by
1065 * 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 interrupt
1069 * 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 register
1085 * @bus: the mii_bus struct
1086 * @addr: the phy address
1087 * @regnum: register number to read
1088 *
1089 * NOTE: MUST NOT be called from interrupt context,
1090 * because the bus read/write functions may wait for an interrupt
1091 * 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 register
1107 * @bus: the mii_bus struct
1108 * @addr: the phy address
1109 * @devad: device address to read
1110 * @regnum: register number to read
1111 *
1112 * NOTE: MUST NOT be called from interrupt context,
1113 * because the bus read/write functions may wait for an interrupt
1114 * 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 function
1130 * @bus: the mii_bus struct
1131 * @addr: the phy address
1132 * @devad: device address to read
1133 * @regnum: register number to read
1134 *
1135 * In case of nested MDIO bus access avoid lockdep false positives by
1136 * 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 interrupt
1140 * 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 function
1157 * @bus: the mii_bus struct
1158 * @addr: the phy address
1159 * @regnum: register number to write
1160 * @val: value to write to @regnum
1161 *
1162 * In case of nested MDIO bus access avoid lockdep false positives by
1163 * 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 interrupt
1167 * 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 register
1183 * @bus: the mii_bus struct
1184 * @addr: the phy address
1185 * @regnum: register number to write
1186 * @val: value to write to @regnum
1187 *
1188 * NOTE: MUST NOT be called from interrupt context,
1189 * because the bus read/write functions may wait for an interrupt
1190 * 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 register
1206 * @bus: the mii_bus struct
1207 * @addr: the phy address
1208 * @devad: device address to read
1209 * @regnum: register number to write
1210 * @val: value to write to @regnum
1211 *
1212 * NOTE: MUST NOT be called from interrupt context,
1213 * because the bus read/write functions may wait for an interrupt
1214 * 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 function
1231 * @bus: the mii_bus struct
1232 * @addr: the phy address
1233 * @devad: device address to read
1234 * @regnum: register number to write
1235 * @val: value to write to @regnum
1236 *
1237 * In case of nested MDIO bus access avoid lockdep false positives by
1238 * 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 interrupt
1242 * 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 device
1259 *	register
1260 * @bus: the mii_bus struct
1261 * @addr: the phy address
1262 * @regnum: register number to write
1263 * @mask: bit mask of bits to clear
1264 * @set: bit mask of bits to set
1265 */
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 device
1279 *	register
1280 * @bus: the mii_bus struct
1281 * @addr: the phy address
1282 * @regnum: register number to write
1283 * @mask: bit mask of bits to clear
1284 * @set: bit mask of bits to set
1285 */
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 device
1300 *	register
1301 * @bus: the mii_bus struct
1302 * @addr: the phy address
1303 * @devad: device address to read
1304 * @regnum: register number to write
1305 * @mask: bit mask of bits to clear
1306 * @set: bit mask of bits to set
1307 */
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 mdio
1324 *	device register and returning if it changed
1325 * @bus: the mii_bus struct
1326 * @addr: the phy address
1327 * @regnum: register number to write
1328 * @mask: bit mask of bits to clear
1329 * @set: bit mask of bits to set
1330 */
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 mdio
1346 *	device register and returning if it changed
1347 * @bus: the mii_bus struct
1348 * @addr: the phy address
1349 * @devad: device address to read
1350 * @regnum: register number to write
1351 * @mask: bit mask of bits to clear
1352 * @set: bit mask of bits to set
1353 */
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 given
1369 *		    MDIO device
1370 * @dev: target MDIO device
1371 * @drv: given MDIO driver
1372 *
1373 * Description: Given a MDIO device, and a MDIO driver, return 1 if
1374 *   the driver supports the device.  Otherwise, return 0. This may
1375 *   require calling the devices own match function, since different classes
1376 *   of MDIO devices have different match criteria.
1377 */
1378static int mdio_bus_match(struct device *dev, struct device_driver *drv)
1379{
1380	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#else
1457module_init(mdio_bus_init);
1458/* no module_exit, intentional */
1459MODULE_LICENSE("GPL");
1460MODULE_DESCRIPTION("MDIO bus/device layer");
1461#endif
1462