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v3.1
  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 */
 16#include <linux/kernel.h>
 17#include <linux/string.h>
 18#include <linux/errno.h>
 19#include <linux/unistd.h>
 20#include <linux/slab.h>
 21#include <linux/interrupt.h>
 22#include <linux/init.h>
 23#include <linux/delay.h>
 24#include <linux/device.h>
 25#include <linux/netdevice.h>
 26#include <linux/etherdevice.h>
 27#include <linux/skbuff.h>
 28#include <linux/spinlock.h>
 
 
 
 
 
 
 29#include <linux/mm.h>
 30#include <linux/module.h>
 31#include <linux/mii.h>
 32#include <linux/ethtool.h>
 
 
 33#include <linux/phy.h>
 
 
 
 
 
 
 
 
 
 
 
 
 34
 35#include <asm/io.h>
 36#include <asm/irq.h>
 37#include <asm/uaccess.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 38
 39/**
 40 * mdiobus_alloc - allocate a mii_bus structure
 
 
 41 *
 42 * Description: called by a bus driver to allocate an mii_bus
 43 * structure to fill in.
 44 */
 45struct mii_bus *mdiobus_alloc(void)
 46{
 47	struct mii_bus *bus;
 
 
 
 
 
 
 
 
 
 
 
 
 
 48
 49	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 50	if (bus != NULL)
 51		bus->state = MDIOBUS_ALLOCATED;
 
 
 
 
 
 
 52
 53	return bus;
 54}
 55EXPORT_SYMBOL(mdiobus_alloc);
 56
 57/**
 58 * mdiobus_release - mii_bus device release callback
 59 * @d: the target struct device that contains the mii_bus
 60 *
 61 * Description: called when the last reference to an mii_bus is
 62 * dropped, to free the underlying memory.
 63 */
 64static void mdiobus_release(struct device *d)
 65{
 66	struct mii_bus *bus = to_mii_bus(d);
 67	BUG_ON(bus->state != MDIOBUS_RELEASED &&
 68	       /* for compatibility with error handling in drivers */
 69	       bus->state != MDIOBUS_ALLOCATED);
 70	kfree(bus);
 71}
 72
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 73static struct class mdio_bus_class = {
 74	.name		= "mdio_bus",
 75	.dev_release	= mdiobus_release,
 
 76};
 77
 78/**
 79 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 80 * @bus: target mii_bus
 
 81 *
 82 * Description: Called by a bus driver to bring up all the PHYs
 83 *   on a given bus, and attach them to the bus.
 
 
 
 
 84 *
 85 * Returns 0 on success or < 0 on error.
 86 */
 87int mdiobus_register(struct mii_bus *bus)
 88{
 
 89	int i, err;
 
 90
 91	if (NULL == bus || NULL == bus->name ||
 92			NULL == bus->read ||
 93			NULL == bus->write)
 94		return -EINVAL;
 95
 96	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
 97	       bus->state != MDIOBUS_UNREGISTERED);
 98
 
 99	bus->dev.parent = bus->parent;
100	bus->dev.class = &mdio_bus_class;
101	bus->dev.groups = NULL;
102	dev_set_name(&bus->dev, "%s", bus->id);
103
104	err = device_register(&bus->dev);
105	if (err) {
106		printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
107		return -EINVAL;
108	}
109
110	mutex_init(&bus->mdio_lock);
 
111
112	if (bus->reset)
113		bus->reset(bus);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
114
115	for (i = 0; i < PHY_MAX_ADDR; i++) {
116		if ((bus->phy_mask & (1 << i)) == 0) {
117			struct phy_device *phydev;
118
119			phydev = mdiobus_scan(bus, i);
120			if (IS_ERR(phydev)) {
121				err = PTR_ERR(phydev);
122				goto error;
123			}
124		}
125	}
126
 
 
127	bus->state = MDIOBUS_REGISTERED;
128	pr_info("%s: probed\n", bus->name);
129	return 0;
130
131error:
132	while (--i >= 0) {
133		if (bus->phy_map[i])
134			device_unregister(&bus->phy_map[i]->dev);
 
 
 
 
135	}
 
 
 
 
 
136	device_del(&bus->dev);
137	return err;
138}
139EXPORT_SYMBOL(mdiobus_register);
140
141void mdiobus_unregister(struct mii_bus *bus)
142{
 
143	int i;
144
145	BUG_ON(bus->state != MDIOBUS_REGISTERED);
146	bus->state = MDIOBUS_UNREGISTERED;
147
148	device_del(&bus->dev);
149	for (i = 0; i < PHY_MAX_ADDR; i++) {
150		if (bus->phy_map[i])
151			device_unregister(&bus->phy_map[i]->dev);
152		bus->phy_map[i] = NULL;
 
 
 
 
 
 
153	}
 
 
 
 
 
 
154}
155EXPORT_SYMBOL(mdiobus_unregister);
156
157/**
158 * mdiobus_free - free a struct mii_bus
159 * @bus: mii_bus to free
160 *
161 * This function releases the reference to the underlying device
162 * object in the mii_bus.  If this is the last reference, the mii_bus
163 * will be freed.
164 */
165void mdiobus_free(struct mii_bus *bus)
166{
167	/*
168	 * For compatibility with error handling in drivers.
169	 */
170	if (bus->state == MDIOBUS_ALLOCATED) {
171		kfree(bus);
172		return;
173	}
174
175	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
176	bus->state = MDIOBUS_RELEASED;
177
178	put_device(&bus->dev);
179}
180EXPORT_SYMBOL(mdiobus_free);
181
 
 
 
 
 
 
 
 
 
 
 
 
182struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
183{
184	struct phy_device *phydev;
185	int err;
186
187	phydev = get_phy_device(bus, addr);
188	if (IS_ERR(phydev) || phydev == NULL)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
189		return phydev;
190
 
 
 
 
 
 
191	err = phy_device_register(phydev);
192	if (err) {
193		phy_device_free(phydev);
194		return NULL;
195	}
196
197	return phydev;
198}
199EXPORT_SYMBOL(mdiobus_scan);
200
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
201/**
202 * mdiobus_read - Convenience function for reading a given MII mgmt register
203 * @bus: the mii_bus struct
204 * @addr: the phy address
205 * @regnum: register number to read
206 *
207 * NOTE: MUST NOT be called from interrupt context,
208 * because the bus read/write functions may wait for an interrupt
209 * to conclude the operation.
210 */
211int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
212{
213	int retval;
214
215	BUG_ON(in_interrupt());
 
216
217	mutex_lock(&bus->mdio_lock);
218	retval = bus->read(bus, addr, regnum);
219	mutex_unlock(&bus->mdio_lock);
220
221	return retval;
222}
223EXPORT_SYMBOL(mdiobus_read);
224
225/**
226 * mdiobus_write - Convenience function for writing a given MII mgmt register
227 * @bus: the mii_bus struct
228 * @addr: the phy address
229 * @regnum: register number to write
230 * @val: value to write to @regnum
231 *
 
 
 
232 * NOTE: MUST NOT be called from interrupt context,
233 * because the bus read/write functions may wait for an interrupt
234 * to conclude the operation.
235 */
236int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
237{
238	int err;
239
240	BUG_ON(in_interrupt());
 
241
242	mutex_lock(&bus->mdio_lock);
243	err = bus->write(bus, addr, regnum, val);
244	mutex_unlock(&bus->mdio_lock);
245
246	return err;
247}
248EXPORT_SYMBOL(mdiobus_write);
249
250/**
251 * mdio_bus_match - determine if given PHY driver supports the given PHY device
252 * @dev: target PHY device
253 * @drv: given PHY driver
 
 
254 *
255 * Description: Given a PHY device, and a PHY driver, return 1 if
256 *   the driver supports the device.  Otherwise, return 0.
 
257 */
258static int mdio_bus_match(struct device *dev, struct device_driver *drv)
259{
260	struct phy_device *phydev = to_phy_device(dev);
261	struct phy_driver *phydrv = to_phy_driver(drv);
262
263	return ((phydrv->phy_id & phydrv->phy_id_mask) ==
264		(phydev->phy_id & phydrv->phy_id_mask));
265}
266
267#ifdef CONFIG_PM
268
269static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
270{
271	struct device_driver *drv = phydev->dev.driver;
272	struct phy_driver *phydrv = to_phy_driver(drv);
273	struct net_device *netdev = phydev->attached_dev;
274
275	if (!drv || !phydrv->suspend)
276		return false;
277
278	/* PHY not attached? May suspend. */
279	if (!netdev)
280		return true;
281
282	/*
283	 * Don't suspend PHY if the attched netdev parent may wakeup.
284	 * The parent may point to a PCI device, as in tg3 driver.
285	 */
286	if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
287		return false;
288
289	/*
290	 * Also don't suspend PHY if the netdev itself may wakeup. This
291	 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
292	 * e.g. SoC devices.
293	 */
294	if (device_may_wakeup(&netdev->dev))
295		return false;
296
297	return true;
298}
 
299
300static int mdio_bus_suspend(struct device *dev)
 
 
 
 
 
 
 
 
 
301{
302	struct phy_driver *phydrv = to_phy_driver(dev->driver);
303	struct phy_device *phydev = to_phy_device(dev);
304
305	/*
306	 * We must stop the state machine manually, otherwise it stops out of
307	 * control, possibly with the phydev->lock held. Upon resume, netdev
308	 * may call phy routines that try to grab the same lock, and that may
309	 * lead to a deadlock.
310	 */
311	if (phydev->attached_dev && phydev->adjust_link)
312		phy_stop_machine(phydev);
313
314	if (!mdio_bus_phy_may_suspend(phydev))
315		return 0;
 
316
317	return phydrv->suspend(phydev);
318}
 
319
320static int mdio_bus_resume(struct device *dev)
 
 
 
 
 
 
 
 
 
 
 
321{
322	struct phy_driver *phydrv = to_phy_driver(dev->driver);
323	struct phy_device *phydev = to_phy_device(dev);
324	int ret;
325
326	if (!mdio_bus_phy_may_suspend(phydev))
327		goto no_resume;
328
329	ret = phydrv->resume(phydev);
330	if (ret < 0)
331		return ret;
332
333no_resume:
334	if (phydev->attached_dev && phydev->adjust_link)
335		phy_start_machine(phydev, NULL);
336
337	return 0;
338}
339
340static int mdio_bus_restore(struct device *dev)
341{
342	struct phy_device *phydev = to_phy_device(dev);
343	struct net_device *netdev = phydev->attached_dev;
344	int ret;
345
346	if (!netdev)
347		return 0;
348
349	ret = phy_init_hw(phydev);
350	if (ret < 0)
351		return ret;
352
353	/* The PHY needs to renegotiate. */
354	phydev->link = 0;
355	phydev->state = PHY_UP;
356
357	phy_start_machine(phydev, NULL);
358
359	return 0;
360}
361
362static struct dev_pm_ops mdio_bus_pm_ops = {
363	.suspend = mdio_bus_suspend,
364	.resume = mdio_bus_resume,
365	.freeze = mdio_bus_suspend,
366	.thaw = mdio_bus_resume,
367	.restore = mdio_bus_restore,
368};
369
370#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
371
372#else
373
374#define MDIO_BUS_PM_OPS NULL
375
376#endif /* CONFIG_PM */
 
 
 
377
378struct bus_type mdio_bus_type = {
379	.name		= "mdio_bus",
 
380	.match		= mdio_bus_match,
381	.pm		= MDIO_BUS_PM_OPS,
382};
383EXPORT_SYMBOL(mdio_bus_type);
384
385int __init mdio_bus_init(void)
386{
387	int ret;
388
389	ret = class_register(&mdio_bus_class);
390	if (!ret) {
391		ret = bus_register(&mdio_bus_type);
392		if (ret)
393			class_unregister(&mdio_bus_class);
394	}
395
396	return ret;
397}
 
398
 
399void mdio_bus_exit(void)
400{
401	class_unregister(&mdio_bus_class);
402	bus_unregister(&mdio_bus_type);
403}
v5.9
   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.h>
  17#include <linux/gpio/consumer.h>
  18#include <linux/init.h>
  19#include <linux/interrupt.h>
  20#include <linux/io.h>
  21#include <linux/kernel.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_gpio.h>
  28#include <linux/of_mdio.h>
  29#include <linux/phy.h>
  30#include <linux/reset.h>
  31#include <linux/skbuff.h>
  32#include <linux/slab.h>
  33#include <linux/spinlock.h>
  34#include <linux/string.h>
  35#include <linux/uaccess.h>
  36#include <linux/unistd.h>
  37
  38#define CREATE_TRACE_POINTS
  39#include <trace/events/mdio.h>
  40
  41#include "mdio-boardinfo.h"
  42
  43static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
  44{
  45	/* Deassert the optional reset signal */
  46	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
  47						 "reset", GPIOD_OUT_LOW);
  48	if (IS_ERR(mdiodev->reset_gpio))
  49		return PTR_ERR(mdiodev->reset_gpio);
  50
  51	if (mdiodev->reset_gpio)
  52		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
  53
  54	return 0;
  55}
  56
  57static int mdiobus_register_reset(struct mdio_device *mdiodev)
  58{
  59	struct reset_control *reset;
  60
  61	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
  62	if (IS_ERR(reset))
  63		return PTR_ERR(reset);
  64
  65	mdiodev->reset_ctrl = reset;
  66
  67	return 0;
  68}
  69
  70int mdiobus_register_device(struct mdio_device *mdiodev)
  71{
  72	int err;
  73
  74	if (mdiodev->bus->mdio_map[mdiodev->addr])
  75		return -EBUSY;
  76
  77	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
  78		err = mdiobus_register_gpiod(mdiodev);
  79		if (err)
  80			return err;
  81
  82		err = mdiobus_register_reset(mdiodev);
  83		if (err)
  84			return err;
  85
  86		/* Assert the reset signal */
  87		mdio_device_reset(mdiodev, 1);
  88	}
  89
  90	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
  91
  92	return 0;
  93}
  94EXPORT_SYMBOL(mdiobus_register_device);
  95
  96int mdiobus_unregister_device(struct mdio_device *mdiodev)
  97{
  98	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
  99		return -EINVAL;
 100
 101	reset_control_put(mdiodev->reset_ctrl);
 102
 103	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
 104
 105	return 0;
 106}
 107EXPORT_SYMBOL(mdiobus_unregister_device);
 108
 109struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
 110{
 111	struct mdio_device *mdiodev = bus->mdio_map[addr];
 112
 113	if (!mdiodev)
 114		return NULL;
 115
 116	if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
 117		return NULL;
 118
 119	return container_of(mdiodev, struct phy_device, mdio);
 120}
 121EXPORT_SYMBOL(mdiobus_get_phy);
 122
 123bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
 124{
 125	return bus->mdio_map[addr];
 126}
 127EXPORT_SYMBOL(mdiobus_is_registered_device);
 128
 129/**
 130 * mdiobus_alloc_size - allocate a mii_bus structure
 131 * @size: extra amount of memory to allocate for private storage.
 132 * If non-zero, then bus->priv is points to that memory.
 133 *
 134 * Description: called by a bus driver to allocate an mii_bus
 135 * structure to fill in.
 136 */
 137struct mii_bus *mdiobus_alloc_size(size_t size)
 138{
 139	struct mii_bus *bus;
 140	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
 141	size_t alloc_size;
 142	int i;
 143
 144	/* If we alloc extra space, it should be aligned */
 145	if (size)
 146		alloc_size = aligned_size + size;
 147	else
 148		alloc_size = sizeof(*bus);
 149
 150	bus = kzalloc(alloc_size, GFP_KERNEL);
 151	if (!bus)
 152		return NULL;
 153
 154	bus->state = MDIOBUS_ALLOCATED;
 155	if (size)
 156		bus->priv = (void *)bus + aligned_size;
 157
 158	/* Initialise the interrupts to polling and 64-bit seqcounts */
 159	for (i = 0; i < PHY_MAX_ADDR; i++) {
 160		bus->irq[i] = PHY_POLL;
 161		u64_stats_init(&bus->stats[i].syncp);
 162	}
 163
 164	return bus;
 165}
 166EXPORT_SYMBOL(mdiobus_alloc_size);
 167
 168/**
 169 * mdiobus_release - mii_bus device release callback
 170 * @d: the target struct device that contains the mii_bus
 171 *
 172 * Description: called when the last reference to an mii_bus is
 173 * dropped, to free the underlying memory.
 174 */
 175static void mdiobus_release(struct device *d)
 176{
 177	struct mii_bus *bus = to_mii_bus(d);
 178	BUG_ON(bus->state != MDIOBUS_RELEASED &&
 179	       /* for compatibility with error handling in drivers */
 180	       bus->state != MDIOBUS_ALLOCATED);
 181	kfree(bus);
 182}
 183
 184struct mdio_bus_stat_attr {
 185	int addr;
 186	unsigned int field_offset;
 187};
 188
 189static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
 190{
 191	const char *p = (const char *)s + offset;
 192	unsigned int start;
 193	u64 val = 0;
 194
 195	do {
 196		start = u64_stats_fetch_begin(&s->syncp);
 197		val = u64_stats_read((const u64_stats_t *)p);
 198	} while (u64_stats_fetch_retry(&s->syncp, start));
 199
 200	return val;
 201}
 202
 203static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
 204{
 205	unsigned int i;
 206	u64 val = 0;
 207
 208	for (i = 0; i < PHY_MAX_ADDR; i++)
 209		val += mdio_bus_get_stat(&bus->stats[i], offset);
 210
 211	return val;
 212}
 213
 214static ssize_t mdio_bus_stat_field_show(struct device *dev,
 215					struct device_attribute *attr,
 216					char *buf)
 217{
 218	struct mii_bus *bus = to_mii_bus(dev);
 219	struct mdio_bus_stat_attr *sattr;
 220	struct dev_ext_attribute *eattr;
 221	u64 val;
 222
 223	eattr = container_of(attr, struct dev_ext_attribute, attr);
 224	sattr = eattr->var;
 225
 226	if (sattr->addr < 0)
 227		val = mdio_bus_get_global_stat(bus, sattr->field_offset);
 228	else
 229		val = mdio_bus_get_stat(&bus->stats[sattr->addr],
 230					sattr->field_offset);
 231
 232	return sprintf(buf, "%llu\n", val);
 233}
 234
 235static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
 236					       struct device_attribute *attr,
 237					       char *buf)
 238{
 239	struct mdio_device *mdiodev = to_mdio_device(dev);
 240	struct mii_bus *bus = mdiodev->bus;
 241	struct mdio_bus_stat_attr *sattr;
 242	struct dev_ext_attribute *eattr;
 243	int addr = mdiodev->addr;
 244	u64 val;
 245
 246	eattr = container_of(attr, struct dev_ext_attribute, attr);
 247	sattr = eattr->var;
 248
 249	val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);
 250
 251	return sprintf(buf, "%llu\n", val);
 252}
 253
 254#define MDIO_BUS_STATS_ATTR_DECL(field, file)				\
 255static struct dev_ext_attribute dev_attr_mdio_bus_##field = {		\
 256	.attr = { .attr = { .name = file, .mode = 0444 },		\
 257		     .show = mdio_bus_stat_field_show,			\
 258	},								\
 259	.var = &((struct mdio_bus_stat_attr) {				\
 260		-1, offsetof(struct mdio_bus_stats, field)		\
 261	}),								\
 262};									\
 263static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = {	\
 264	.attr = { .attr = { .name = file, .mode = 0444 },		\
 265		     .show = mdio_bus_device_stat_field_show,		\
 266	},								\
 267	.var = &((struct mdio_bus_stat_attr) {				\
 268		-1, offsetof(struct mdio_bus_stats, field)		\
 269	}),								\
 270};
 271
 272#define MDIO_BUS_STATS_ATTR(field)					\
 273	MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
 274
 275MDIO_BUS_STATS_ATTR(transfers);
 276MDIO_BUS_STATS_ATTR(errors);
 277MDIO_BUS_STATS_ATTR(writes);
 278MDIO_BUS_STATS_ATTR(reads);
 279
 280#define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file)		\
 281static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \
 282	.attr = { .attr = { .name = file, .mode = 0444 },		\
 283		     .show = mdio_bus_stat_field_show,			\
 284	},								\
 285	.var = &((struct mdio_bus_stat_attr) {				\
 286		addr, offsetof(struct mdio_bus_stats, field)		\
 287	}),								\
 288}
 289
 290#define MDIO_BUS_STATS_ADDR_ATTR(field, addr)				\
 291	MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr,			\
 292				 __stringify(field) "_" __stringify(addr))
 293
 294#define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr)			\
 295	MDIO_BUS_STATS_ADDR_ATTR(transfers, addr);			\
 296	MDIO_BUS_STATS_ADDR_ATTR(errors, addr);				\
 297	MDIO_BUS_STATS_ADDR_ATTR(writes, addr);				\
 298	MDIO_BUS_STATS_ADDR_ATTR(reads, addr)				\
 299
 300MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
 301MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
 302MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
 303MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
 304MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
 305MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
 306MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
 307MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
 308MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
 309MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
 310MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
 311MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
 312MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
 313MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
 314MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
 315MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
 316MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
 317MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
 318MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
 319MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
 320MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
 321MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
 322MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
 323MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
 324MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
 325MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
 326MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
 327MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
 328MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
 329MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
 330MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
 331MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
 332
 333#define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr)				\
 334	&dev_attr_mdio_bus_addr_transfers_##addr.attr.attr,		\
 335	&dev_attr_mdio_bus_addr_errors_##addr.attr.attr,		\
 336	&dev_attr_mdio_bus_addr_writes_##addr.attr.attr,		\
 337	&dev_attr_mdio_bus_addr_reads_##addr.attr.attr			\
 338
 339static struct attribute *mdio_bus_statistics_attrs[] = {
 340	&dev_attr_mdio_bus_transfers.attr.attr,
 341	&dev_attr_mdio_bus_errors.attr.attr,
 342	&dev_attr_mdio_bus_writes.attr.attr,
 343	&dev_attr_mdio_bus_reads.attr.attr,
 344	MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),
 345	MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),
 346	MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),
 347	MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),
 348	MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),
 349	MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),
 350	MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),
 351	MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),
 352	MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),
 353	MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),
 354	MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),
 355	MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),
 356	MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),
 357	MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),
 358	MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),
 359	MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),
 360	MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),
 361	MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),
 362	MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),
 363	MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),
 364	MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),
 365	MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),
 366	MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),
 367	MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),
 368	MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),
 369	MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),
 370	MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),
 371	MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),
 372	MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),
 373	MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),
 374	MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),
 375	MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),
 376	NULL,
 377};
 378
 379static const struct attribute_group mdio_bus_statistics_group = {
 380	.name	= "statistics",
 381	.attrs	= mdio_bus_statistics_attrs,
 382};
 383
 384static const struct attribute_group *mdio_bus_groups[] = {
 385	&mdio_bus_statistics_group,
 386	NULL,
 387};
 388
 389static struct class mdio_bus_class = {
 390	.name		= "mdio_bus",
 391	.dev_release	= mdiobus_release,
 392	.dev_groups	= mdio_bus_groups,
 393};
 394
 395/**
 396 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
 397 * @mdio_name: The name of a mdiobus.
 398 *
 399 * Returns a reference to the mii_bus, or NULL if none found.  The
 400 * embedded struct device will have its reference count incremented,
 401 * and this must be put_deviced'ed once the bus is finished with.
 402 */
 403struct mii_bus *mdio_find_bus(const char *mdio_name)
 404{
 405	struct device *d;
 406
 407	d = class_find_device_by_name(&mdio_bus_class, mdio_name);
 408	return d ? to_mii_bus(d) : NULL;
 409}
 410EXPORT_SYMBOL(mdio_find_bus);
 411
 412#if IS_ENABLED(CONFIG_OF_MDIO)
 413/**
 414 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
 415 * @mdio_bus_np: Pointer to the mii_bus.
 416 *
 417 * Returns a reference to the mii_bus, or NULL if none found.  The
 418 * embedded struct device will have its reference count incremented,
 419 * and this must be put once the bus is finished with.
 420 *
 421 * Because the association of a device_node and mii_bus is made via
 422 * of_mdiobus_register(), the mii_bus cannot be found before it is
 423 * registered with of_mdiobus_register().
 424 *
 425 */
 426struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
 427{
 428	struct device *d;
 429
 430	if (!mdio_bus_np)
 431		return NULL;
 432
 433	d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
 434	return d ? to_mii_bus(d) : NULL;
 435}
 436EXPORT_SYMBOL(of_mdio_find_bus);
 437
 438/* Walk the list of subnodes of a mdio bus and look for a node that
 439 * matches the mdio device's address with its 'reg' property. If
 440 * found, set the of_node pointer for the mdio device. This allows
 441 * auto-probed phy devices to be supplied with information passed in
 442 * via DT.
 443 */
 444static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
 445				    struct mdio_device *mdiodev)
 446{
 447	struct device *dev = &mdiodev->dev;
 448	struct device_node *child;
 449
 450	if (dev->of_node || !bus->dev.of_node)
 451		return;
 452
 453	for_each_available_child_of_node(bus->dev.of_node, child) {
 454		int addr;
 455
 456		addr = of_mdio_parse_addr(dev, child);
 457		if (addr < 0)
 458			continue;
 459
 460		if (addr == mdiodev->addr) {
 461			dev->of_node = child;
 462			dev->fwnode = of_fwnode_handle(child);
 463			return;
 464		}
 465	}
 466}
 467#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
 468static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
 469					   struct mdio_device *mdiodev)
 470{
 471}
 472#endif
 473
 474/**
 475 * mdiobus_create_device_from_board_info - create a full MDIO device given
 476 * a mdio_board_info structure
 477 * @bus: MDIO bus to create the devices on
 478 * @bi: mdio_board_info structure describing the devices
 479 *
 480 * Returns 0 on success or < 0 on error.
 481 */
 482static int mdiobus_create_device(struct mii_bus *bus,
 483				 struct mdio_board_info *bi)
 484{
 485	struct mdio_device *mdiodev;
 486	int ret = 0;
 487
 488	mdiodev = mdio_device_create(bus, bi->mdio_addr);
 489	if (IS_ERR(mdiodev))
 490		return -ENODEV;
 491
 492	strncpy(mdiodev->modalias, bi->modalias,
 493		sizeof(mdiodev->modalias));
 494	mdiodev->bus_match = mdio_device_bus_match;
 495	mdiodev->dev.platform_data = (void *)bi->platform_data;
 496
 497	ret = mdio_device_register(mdiodev);
 498	if (ret)
 499		mdio_device_free(mdiodev);
 500
 501	return ret;
 502}
 503
 504/**
 505 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
 506 * @bus: target mii_bus
 507 * @owner: module containing bus accessor functions
 508 *
 509 * Description: Called by a bus driver to bring up all the PHYs
 510 *   on a given bus, and attach them to the bus. Drivers should use
 511 *   mdiobus_register() rather than __mdiobus_register() unless they
 512 *   need to pass a specific owner module. MDIO devices which are not
 513 *   PHYs will not be brought up by this function. They are expected to
 514 *   to be explicitly listed in DT and instantiated by of_mdiobus_register().
 515 *
 516 * Returns 0 on success or < 0 on error.
 517 */
 518int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 519{
 520	struct mdio_device *mdiodev;
 521	int i, err;
 522	struct gpio_desc *gpiod;
 523
 524	if (NULL == bus || NULL == bus->name ||
 525	    NULL == bus->read || NULL == bus->write)
 
 526		return -EINVAL;
 527
 528	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
 529	       bus->state != MDIOBUS_UNREGISTERED);
 530
 531	bus->owner = owner;
 532	bus->dev.parent = bus->parent;
 533	bus->dev.class = &mdio_bus_class;
 534	bus->dev.groups = NULL;
 535	dev_set_name(&bus->dev, "%s", bus->id);
 536
 537	err = device_register(&bus->dev);
 538	if (err) {
 539		pr_err("mii_bus %s failed to register\n", bus->id);
 540		return -EINVAL;
 541	}
 542
 543	mutex_init(&bus->mdio_lock);
 544	mutex_init(&bus->shared_lock);
 545
 546	/* de-assert bus level PHY GPIO reset */
 547	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
 548	if (IS_ERR(gpiod)) {
 549		dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
 550			bus->id);
 551		device_del(&bus->dev);
 552		return PTR_ERR(gpiod);
 553	} else	if (gpiod) {
 554		bus->reset_gpiod = gpiod;
 555
 556		gpiod_set_value_cansleep(gpiod, 1);
 557		fsleep(bus->reset_delay_us);
 558		gpiod_set_value_cansleep(gpiod, 0);
 559		if (bus->reset_post_delay_us > 0)
 560			fsleep(bus->reset_post_delay_us);
 561	}
 562
 563	if (bus->reset) {
 564		err = bus->reset(bus);
 565		if (err)
 566			goto error_reset_gpiod;
 567	}
 568
 569	for (i = 0; i < PHY_MAX_ADDR; i++) {
 570		if ((bus->phy_mask & (1 << i)) == 0) {
 571			struct phy_device *phydev;
 572
 573			phydev = mdiobus_scan(bus, i);
 574			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
 575				err = PTR_ERR(phydev);
 576				goto error;
 577			}
 578		}
 579	}
 580
 581	mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
 582
 583	bus->state = MDIOBUS_REGISTERED;
 584	pr_info("%s: probed\n", bus->name);
 585	return 0;
 586
 587error:
 588	while (--i >= 0) {
 589		mdiodev = bus->mdio_map[i];
 590		if (!mdiodev)
 591			continue;
 592
 593		mdiodev->device_remove(mdiodev);
 594		mdiodev->device_free(mdiodev);
 595	}
 596error_reset_gpiod:
 597	/* Put PHYs in RESET to save power */
 598	if (bus->reset_gpiod)
 599		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
 600
 601	device_del(&bus->dev);
 602	return err;
 603}
 604EXPORT_SYMBOL(__mdiobus_register);
 605
 606void mdiobus_unregister(struct mii_bus *bus)
 607{
 608	struct mdio_device *mdiodev;
 609	int i;
 610
 611	BUG_ON(bus->state != MDIOBUS_REGISTERED);
 612	bus->state = MDIOBUS_UNREGISTERED;
 613
 
 614	for (i = 0; i < PHY_MAX_ADDR; i++) {
 615		mdiodev = bus->mdio_map[i];
 616		if (!mdiodev)
 617			continue;
 618
 619		if (mdiodev->reset_gpio)
 620			gpiod_put(mdiodev->reset_gpio);
 621
 622		mdiodev->device_remove(mdiodev);
 623		mdiodev->device_free(mdiodev);
 624	}
 625
 626	/* Put PHYs in RESET to save power */
 627	if (bus->reset_gpiod)
 628		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
 629
 630	device_del(&bus->dev);
 631}
 632EXPORT_SYMBOL(mdiobus_unregister);
 633
 634/**
 635 * mdiobus_free - free a struct mii_bus
 636 * @bus: mii_bus to free
 637 *
 638 * This function releases the reference to the underlying device
 639 * object in the mii_bus.  If this is the last reference, the mii_bus
 640 * will be freed.
 641 */
 642void mdiobus_free(struct mii_bus *bus)
 643{
 644	/* For compatibility with error handling in drivers. */
 
 
 645	if (bus->state == MDIOBUS_ALLOCATED) {
 646		kfree(bus);
 647		return;
 648	}
 649
 650	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
 651	bus->state = MDIOBUS_RELEASED;
 652
 653	put_device(&bus->dev);
 654}
 655EXPORT_SYMBOL(mdiobus_free);
 656
 657/**
 658 * mdiobus_scan - scan a bus for MDIO devices.
 659 * @bus: mii_bus to scan
 660 * @addr: address on bus to scan
 661 *
 662 * This function scans the MDIO bus, looking for devices which can be
 663 * identified using a vendor/product ID in registers 2 and 3. Not all
 664 * MDIO devices have such registers, but PHY devices typically
 665 * do. Hence this function assumes anything found is a PHY, or can be
 666 * treated as a PHY. Other MDIO devices, such as switches, will
 667 * probably not be found during the scan.
 668 */
 669struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 670{
 671	struct phy_device *phydev = ERR_PTR(-ENODEV);
 672	int err;
 673
 674	switch (bus->probe_capabilities) {
 675	case MDIOBUS_NO_CAP:
 676	case MDIOBUS_C22:
 677		phydev = get_phy_device(bus, addr, false);
 678		break;
 679	case MDIOBUS_C45:
 680		phydev = get_phy_device(bus, addr, true);
 681		break;
 682	case MDIOBUS_C22_C45:
 683		phydev = get_phy_device(bus, addr, false);
 684		if (IS_ERR(phydev))
 685			phydev = get_phy_device(bus, addr, true);
 686		break;
 687	}
 688
 689	if (IS_ERR(phydev))
 690		return phydev;
 691
 692	/*
 693	 * For DT, see if the auto-probed phy has a correspoding child
 694	 * in the bus node, and set the of_node pointer in this case.
 695	 */
 696	of_mdiobus_link_mdiodev(bus, &phydev->mdio);
 697
 698	err = phy_device_register(phydev);
 699	if (err) {
 700		phy_device_free(phydev);
 701		return ERR_PTR(-ENODEV);
 702	}
 703
 704	return phydev;
 705}
 706EXPORT_SYMBOL(mdiobus_scan);
 707
 708static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
 709{
 710	preempt_disable();
 711	u64_stats_update_begin(&stats->syncp);
 712
 713	u64_stats_inc(&stats->transfers);
 714	if (ret < 0) {
 715		u64_stats_inc(&stats->errors);
 716		goto out;
 717	}
 718
 719	if (op)
 720		u64_stats_inc(&stats->reads);
 721	else
 722		u64_stats_inc(&stats->writes);
 723out:
 724	u64_stats_update_end(&stats->syncp);
 725	preempt_enable();
 726}
 727
 728/**
 729 * __mdiobus_read - Unlocked version of the mdiobus_read function
 730 * @bus: the mii_bus struct
 731 * @addr: the phy address
 732 * @regnum: register number to read
 733 *
 734 * Read a MDIO bus register. Caller must hold the mdio bus lock.
 735 *
 736 * NOTE: MUST NOT be called from interrupt context.
 737 */
 738int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 739{
 740	int retval;
 741
 742	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
 743
 744	retval = bus->read(bus, addr, regnum);
 745
 746	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
 747	mdiobus_stats_acct(&bus->stats[addr], true, retval);
 748
 749	return retval;
 750}
 751EXPORT_SYMBOL(__mdiobus_read);
 752
 753/**
 754 * __mdiobus_write - Unlocked version of the mdiobus_write function
 755 * @bus: the mii_bus struct
 756 * @addr: the phy address
 757 * @regnum: register number to write
 758 * @val: value to write to @regnum
 759 *
 760 * Write a MDIO bus register. Caller must hold the mdio bus lock.
 761 *
 762 * NOTE: MUST NOT be called from interrupt context.
 763 */
 764int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 765{
 766	int err;
 767
 768	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
 769
 770	err = bus->write(bus, addr, regnum, val);
 771
 772	trace_mdio_access(bus, 0, addr, regnum, val, err);
 773	mdiobus_stats_acct(&bus->stats[addr], false, err);
 774
 775	return err;
 776}
 777EXPORT_SYMBOL(__mdiobus_write);
 778
 779/**
 780 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
 781 * @bus: the mii_bus struct
 782 * @addr: the phy address
 783 * @regnum: register number to modify
 784 * @mask: bit mask of bits to clear
 785 * @set: bit mask of bits to set
 786 *
 787 * Read, modify, and if any change, write the register value back to the
 788 * device. Any error returns a negative number.
 789 *
 790 * NOTE: MUST NOT be called from interrupt context.
 791 */
 792int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
 793			     u16 mask, u16 set)
 794{
 795	int new, ret;
 796
 797	ret = __mdiobus_read(bus, addr, regnum);
 798	if (ret < 0)
 799		return ret;
 800
 801	new = (ret & ~mask) | set;
 802	if (new == ret)
 803		return 0;
 804
 805	ret = __mdiobus_write(bus, addr, regnum, new);
 806
 807	return ret < 0 ? ret : 1;
 808}
 809EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
 810
 811/**
 812 * mdiobus_read_nested - Nested version of the mdiobus_read function
 813 * @bus: the mii_bus struct
 814 * @addr: the phy address
 815 * @regnum: register number to read
 816 *
 817 * In case of nested MDIO bus access avoid lockdep false positives by
 818 * using mutex_lock_nested().
 819 *
 820 * NOTE: MUST NOT be called from interrupt context,
 821 * because the bus read/write functions may wait for an interrupt
 822 * to conclude the operation.
 823 */
 824int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
 825{
 826	int retval;
 827
 828	if (WARN_ON_ONCE(in_interrupt()))
 829		return -EINVAL;
 830
 831	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 832	retval = __mdiobus_read(bus, addr, regnum);
 833	mutex_unlock(&bus->mdio_lock);
 834
 835	return retval;
 836}
 837EXPORT_SYMBOL(mdiobus_read_nested);
 838
 839/**
 840 * mdiobus_read - Convenience function for reading a given MII mgmt register
 841 * @bus: the mii_bus struct
 842 * @addr: the phy address
 843 * @regnum: register number to read
 844 *
 845 * NOTE: MUST NOT be called from interrupt context,
 846 * because the bus read/write functions may wait for an interrupt
 847 * to conclude the operation.
 848 */
 849int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 850{
 851	int retval;
 852
 853	if (WARN_ON_ONCE(in_interrupt()))
 854		return -EINVAL;
 855
 856	mutex_lock(&bus->mdio_lock);
 857	retval = __mdiobus_read(bus, addr, regnum);
 858	mutex_unlock(&bus->mdio_lock);
 859
 860	return retval;
 861}
 862EXPORT_SYMBOL(mdiobus_read);
 863
 864/**
 865 * mdiobus_write_nested - Nested version of the mdiobus_write function
 866 * @bus: the mii_bus struct
 867 * @addr: the phy address
 868 * @regnum: register number to write
 869 * @val: value to write to @regnum
 870 *
 871 * In case of nested MDIO bus access avoid lockdep false positives by
 872 * using mutex_lock_nested().
 873 *
 874 * NOTE: MUST NOT be called from interrupt context,
 875 * because the bus read/write functions may wait for an interrupt
 876 * to conclude the operation.
 877 */
 878int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 879{
 880	int err;
 881
 882	if (WARN_ON_ONCE(in_interrupt()))
 883		return -EINVAL;
 884
 885	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
 886	err = __mdiobus_write(bus, addr, regnum, val);
 887	mutex_unlock(&bus->mdio_lock);
 888
 889	return err;
 890}
 891EXPORT_SYMBOL(mdiobus_write_nested);
 892
 893/**
 894 * mdiobus_write - Convenience function for writing a given MII mgmt register
 895 * @bus: the mii_bus struct
 896 * @addr: the phy address
 897 * @regnum: register number to write
 898 * @val: value to write to @regnum
 899 *
 900 * NOTE: MUST NOT be called from interrupt context,
 901 * because the bus read/write functions may wait for an interrupt
 902 * to conclude the operation.
 903 */
 904int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 
 
 
 
 
 
 
 
 
 
 
 905{
 906	int err;
 
 
 
 
 
 
 
 
 
 907
 908	if (WARN_ON_ONCE(in_interrupt()))
 909		return -EINVAL;
 
 
 
 
 910
 911	mutex_lock(&bus->mdio_lock);
 912	err = __mdiobus_write(bus, addr, regnum, val);
 913	mutex_unlock(&bus->mdio_lock);
 
 
 
 
 914
 915	return err;
 916}
 917EXPORT_SYMBOL(mdiobus_write);
 918
 919/**
 920 * mdiobus_modify - Convenience function for modifying a given mdio device
 921 *	register
 922 * @bus: the mii_bus struct
 923 * @addr: the phy address
 924 * @regnum: register number to write
 925 * @mask: bit mask of bits to clear
 926 * @set: bit mask of bits to set
 927 */
 928int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
 929{
 930	int err;
 
 931
 932	if (WARN_ON_ONCE(in_interrupt()))
 933		return -EINVAL;
 
 
 
 
 
 
 934
 935	mutex_lock(&bus->mdio_lock);
 936	err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
 937	mutex_unlock(&bus->mdio_lock);
 938
 939	return err < 0 ? err : 0;
 940}
 941EXPORT_SYMBOL_GPL(mdiobus_modify);
 942
 943/**
 944 * mdio_bus_match - determine if given MDIO driver supports the given
 945 *		    MDIO device
 946 * @dev: target MDIO device
 947 * @drv: given MDIO driver
 948 *
 949 * Description: Given a MDIO device, and a MDIO driver, return 1 if
 950 *   the driver supports the device.  Otherwise, return 0. This may
 951 *   require calling the devices own match function, since different classes
 952 *   of MDIO devices have different match criteria.
 953 */
 954static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 955{
 956	struct mdio_device *mdio = to_mdio_device(dev);
 
 
 
 
 
 957
 958	if (of_driver_match_device(dev, drv))
 959		return 1;
 
 960
 961	if (mdio->bus_match)
 962		return mdio->bus_match(dev, drv);
 
 963
 964	return 0;
 965}
 966
 967static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
 968{
 969	int rc;
 
 
 
 
 
 970
 971	/* Some devices have extra OF data and an OF-style MODALIAS */
 972	rc = of_device_uevent_modalias(dev, env);
 973	if (rc != -ENODEV)
 974		return rc;
 
 
 
 
 
 975
 976	return 0;
 977}
 978
 979static struct attribute *mdio_bus_device_statistics_attrs[] = {
 980	&dev_attr_mdio_bus_device_transfers.attr.attr,
 981	&dev_attr_mdio_bus_device_errors.attr.attr,
 982	&dev_attr_mdio_bus_device_writes.attr.attr,
 983	&dev_attr_mdio_bus_device_reads.attr.attr,
 984	NULL,
 985};
 986
 987static const struct attribute_group mdio_bus_device_statistics_group = {
 988	.name	= "statistics",
 989	.attrs	= mdio_bus_device_statistics_attrs,
 990};
 
 991
 992static const struct attribute_group *mdio_bus_dev_groups[] = {
 993	&mdio_bus_device_statistics_group,
 994	NULL,
 995};
 996
 997struct bus_type mdio_bus_type = {
 998	.name		= "mdio_bus",
 999	.dev_groups	= mdio_bus_dev_groups,
1000	.match		= mdio_bus_match,
1001	.uevent		= mdio_uevent,
1002};
1003EXPORT_SYMBOL(mdio_bus_type);
1004
1005int __init mdio_bus_init(void)
1006{
1007	int ret;
1008
1009	ret = class_register(&mdio_bus_class);
1010	if (!ret) {
1011		ret = bus_register(&mdio_bus_type);
1012		if (ret)
1013			class_unregister(&mdio_bus_class);
1014	}
1015
1016	return ret;
1017}
1018EXPORT_SYMBOL_GPL(mdio_bus_init);
1019
1020#if IS_ENABLED(CONFIG_PHYLIB)
1021void mdio_bus_exit(void)
1022{
1023	class_unregister(&mdio_bus_class);
1024	bus_unregister(&mdio_bus_type);
1025}
1026EXPORT_SYMBOL_GPL(mdio_bus_exit);
1027#else
1028module_init(mdio_bus_init);
1029/* no module_exit, intentional */
1030MODULE_LICENSE("GPL");
1031MODULE_DESCRIPTION("MDIO bus/device layer");
1032#endif