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/micrel_phy.h>
23#include <linux/mii.h>
24#include <linux/mm.h>
25#include <linux/module.h>
26#include <linux/netdevice.h>
27#include <linux/of_device.h>
28#include <linux/of_gpio.h>
29#include <linux/of_mdio.h>
30#include <linux/phy.h>
31#include <linux/reset.h>
32#include <linux/skbuff.h>
33#include <linux/slab.h>
34#include <linux/spinlock.h>
35#include <linux/string.h>
36#include <linux/uaccess.h>
37#include <linux/unistd.h>
38
39#define CREATE_TRACE_POINTS
40#include <trace/events/mdio.h>
41
42#include "mdio-boardinfo.h"
43
44static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
45{
46 /* Deassert the optional reset signal */
47 mdiodev->reset_gpio = gpiod_get_optional(dev: &mdiodev->dev,
48 con_id: "reset", flags: GPIOD_OUT_LOW);
49 if (IS_ERR(ptr: mdiodev->reset_gpio))
50 return PTR_ERR(ptr: mdiodev->reset_gpio);
51
52 if (mdiodev->reset_gpio)
53 gpiod_set_consumer_name(desc: mdiodev->reset_gpio, name: "PHY reset");
54
55 return 0;
56}
57
58static int mdiobus_register_reset(struct mdio_device *mdiodev)
59{
60 struct reset_control *reset;
61
62 reset = reset_control_get_optional_exclusive(dev: &mdiodev->dev, id: "phy");
63 if (IS_ERR(ptr: reset))
64 return PTR_ERR(ptr: reset);
65
66 mdiodev->reset_ctrl = reset;
67
68 return 0;
69}
70
71int mdiobus_register_device(struct mdio_device *mdiodev)
72{
73 int err;
74
75 if (mdiodev->bus->mdio_map[mdiodev->addr])
76 return -EBUSY;
77
78 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
79 err = mdiobus_register_gpiod(mdiodev);
80 if (err)
81 return err;
82
83 err = mdiobus_register_reset(mdiodev);
84 if (err)
85 return err;
86
87 /* Assert the reset signal */
88 mdio_device_reset(mdiodev, value: 1);
89 }
90
91 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
92
93 return 0;
94}
95EXPORT_SYMBOL(mdiobus_register_device);
96
97int mdiobus_unregister_device(struct mdio_device *mdiodev)
98{
99 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
100 return -EINVAL;
101
102 reset_control_put(rstc: mdiodev->reset_ctrl);
103
104 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
105
106 return 0;
107}
108EXPORT_SYMBOL(mdiobus_unregister_device);
109
110static struct mdio_device *mdiobus_find_device(struct mii_bus *bus, int addr)
111{
112 bool addr_valid = addr >= 0 && addr < ARRAY_SIZE(bus->mdio_map);
113
114 if (WARN_ONCE(!addr_valid, "addr %d out of range\n", addr))
115 return NULL;
116
117 return bus->mdio_map[addr];
118}
119
120struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
121{
122 struct mdio_device *mdiodev;
123
124 mdiodev = mdiobus_find_device(bus, addr);
125 if (!mdiodev)
126 return NULL;
127
128 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
129 return NULL;
130
131 return container_of(mdiodev, struct phy_device, mdio);
132}
133EXPORT_SYMBOL(mdiobus_get_phy);
134
135bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
136{
137 return mdiobus_find_device(bus, addr) != NULL;
138}
139EXPORT_SYMBOL(mdiobus_is_registered_device);
140
141/**
142 * mdiobus_alloc_size - allocate a mii_bus structure
143 * @size: extra amount of memory to allocate for private storage.
144 * If non-zero, then bus->priv is points to that memory.
145 *
146 * Description: called by a bus driver to allocate an mii_bus
147 * structure to fill in.
148 */
149struct mii_bus *mdiobus_alloc_size(size_t size)
150{
151 struct mii_bus *bus;
152 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
153 size_t alloc_size;
154 int i;
155
156 /* If we alloc extra space, it should be aligned */
157 if (size)
158 alloc_size = aligned_size + size;
159 else
160 alloc_size = sizeof(*bus);
161
162 bus = kzalloc(size: alloc_size, GFP_KERNEL);
163 if (!bus)
164 return NULL;
165
166 bus->state = MDIOBUS_ALLOCATED;
167 if (size)
168 bus->priv = (void *)bus + aligned_size;
169
170 /* Initialise the interrupts to polling and 64-bit seqcounts */
171 for (i = 0; i < PHY_MAX_ADDR; i++) {
172 bus->irq[i] = PHY_POLL;
173 u64_stats_init(syncp: &bus->stats[i].syncp);
174 }
175
176 return bus;
177}
178EXPORT_SYMBOL(mdiobus_alloc_size);
179
180/**
181 * mdiobus_release - mii_bus device release callback
182 * @d: the target struct device that contains the mii_bus
183 *
184 * Description: called when the last reference to an mii_bus is
185 * dropped, to free the underlying memory.
186 */
187static void mdiobus_release(struct device *d)
188{
189 struct mii_bus *bus = to_mii_bus(d);
190
191 WARN(bus->state != MDIOBUS_RELEASED &&
192 /* for compatibility with error handling in drivers */
193 bus->state != MDIOBUS_ALLOCATED,
194 "%s: not in RELEASED or ALLOCATED state\n",
195 bus->id);
196 kfree(objp: bus);
197}
198
199struct mdio_bus_stat_attr {
200 int addr;
201 unsigned int field_offset;
202};
203
204static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
205{
206 const char *p = (const char *)s + offset;
207 unsigned int start;
208 u64 val = 0;
209
210 do {
211 start = u64_stats_fetch_begin(syncp: &s->syncp);
212 val = u64_stats_read(p: (const u64_stats_t *)p);
213 } while (u64_stats_fetch_retry(syncp: &s->syncp, start));
214
215 return val;
216}
217
218static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
219{
220 unsigned int i;
221 u64 val = 0;
222
223 for (i = 0; i < PHY_MAX_ADDR; i++)
224 val += mdio_bus_get_stat(s: &bus->stats[i], offset);
225
226 return val;
227}
228
229static ssize_t mdio_bus_stat_field_show(struct device *dev,
230 struct device_attribute *attr,
231 char *buf)
232{
233 struct mii_bus *bus = to_mii_bus(dev);
234 struct mdio_bus_stat_attr *sattr;
235 struct dev_ext_attribute *eattr;
236 u64 val;
237
238 eattr = container_of(attr, struct dev_ext_attribute, attr);
239 sattr = eattr->var;
240
241 if (sattr->addr < 0)
242 val = mdio_bus_get_global_stat(bus, offset: sattr->field_offset);
243 else
244 val = mdio_bus_get_stat(s: &bus->stats[sattr->addr],
245 offset: sattr->field_offset);
246
247 return sysfs_emit(buf, fmt: "%llu\n", val);
248}
249
250static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
251 struct device_attribute *attr,
252 char *buf)
253{
254 struct mdio_device *mdiodev = to_mdio_device(dev);
255 struct mii_bus *bus = mdiodev->bus;
256 struct mdio_bus_stat_attr *sattr;
257 struct dev_ext_attribute *eattr;
258 int addr = mdiodev->addr;
259 u64 val;
260
261 eattr = container_of(attr, struct dev_ext_attribute, attr);
262 sattr = eattr->var;
263
264 val = mdio_bus_get_stat(s: &bus->stats[addr], offset: sattr->field_offset);
265
266 return sysfs_emit(buf, fmt: "%llu\n", val);
267}
268
269#define MDIO_BUS_STATS_ATTR_DECL(field, file) \
270static struct dev_ext_attribute dev_attr_mdio_bus_##field = { \
271 .attr = { .attr = { .name = file, .mode = 0444 }, \
272 .show = mdio_bus_stat_field_show, \
273 }, \
274 .var = &((struct mdio_bus_stat_attr) { \
275 -1, offsetof(struct mdio_bus_stats, field) \
276 }), \
277}; \
278static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = { \
279 .attr = { .attr = { .name = file, .mode = 0444 }, \
280 .show = mdio_bus_device_stat_field_show, \
281 }, \
282 .var = &((struct mdio_bus_stat_attr) { \
283 -1, offsetof(struct mdio_bus_stats, field) \
284 }), \
285};
286
287#define MDIO_BUS_STATS_ATTR(field) \
288 MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
289
290MDIO_BUS_STATS_ATTR(transfers);
291MDIO_BUS_STATS_ATTR(errors);
292MDIO_BUS_STATS_ATTR(writes);
293MDIO_BUS_STATS_ATTR(reads);
294
295#define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file) \
296static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \
297 .attr = { .attr = { .name = file, .mode = 0444 }, \
298 .show = mdio_bus_stat_field_show, \
299 }, \
300 .var = &((struct mdio_bus_stat_attr) { \
301 addr, offsetof(struct mdio_bus_stats, field) \
302 }), \
303}
304
305#define MDIO_BUS_STATS_ADDR_ATTR(field, addr) \
306 MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, \
307 __stringify(field) "_" __stringify(addr))
308
309#define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr) \
310 MDIO_BUS_STATS_ADDR_ATTR(transfers, addr); \
311 MDIO_BUS_STATS_ADDR_ATTR(errors, addr); \
312 MDIO_BUS_STATS_ADDR_ATTR(writes, addr); \
313 MDIO_BUS_STATS_ADDR_ATTR(reads, addr) \
314
315MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
316MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
317MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
318MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
319MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
320MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
321MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
322MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
323MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
324MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
325MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
326MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
327MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
328MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
329MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
330MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
331MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
332MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
333MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
334MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
335MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
336MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
337MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
338MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
339MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
340MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
341MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
342MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
343MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
344MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
345MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
346MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
347
348#define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr) \
349 &dev_attr_mdio_bus_addr_transfers_##addr.attr.attr, \
350 &dev_attr_mdio_bus_addr_errors_##addr.attr.attr, \
351 &dev_attr_mdio_bus_addr_writes_##addr.attr.attr, \
352 &dev_attr_mdio_bus_addr_reads_##addr.attr.attr \
353
354static struct attribute *mdio_bus_statistics_attrs[] = {
355 &dev_attr_mdio_bus_transfers.attr.attr,
356 &dev_attr_mdio_bus_errors.attr.attr,
357 &dev_attr_mdio_bus_writes.attr.attr,
358 &dev_attr_mdio_bus_reads.attr.attr,
359 MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),
360 MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),
361 MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),
362 MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),
363 MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),
364 MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),
365 MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),
366 MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),
367 MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),
368 MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),
369 MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),
370 MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),
371 MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),
372 MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),
373 MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),
374 MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),
375 MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),
376 MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),
377 MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),
378 MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),
379 MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),
380 MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),
381 MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),
382 MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),
383 MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),
384 MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),
385 MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),
386 MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),
387 MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),
388 MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),
389 MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),
390 MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),
391 NULL,
392};
393
394static const struct attribute_group mdio_bus_statistics_group = {
395 .name = "statistics",
396 .attrs = mdio_bus_statistics_attrs,
397};
398
399static const struct attribute_group *mdio_bus_groups[] = {
400 &mdio_bus_statistics_group,
401 NULL,
402};
403
404static struct class mdio_bus_class = {
405 .name = "mdio_bus",
406 .dev_release = mdiobus_release,
407 .dev_groups = mdio_bus_groups,
408};
409
410/**
411 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
412 * @mdio_name: The name of a mdiobus.
413 *
414 * Returns a reference to the mii_bus, or NULL if none found. The
415 * embedded struct device will have its reference count incremented,
416 * and this must be put_deviced'ed once the bus is finished with.
417 */
418struct mii_bus *mdio_find_bus(const char *mdio_name)
419{
420 struct device *d;
421
422 d = class_find_device_by_name(class: &mdio_bus_class, name: mdio_name);
423 return d ? to_mii_bus(d) : NULL;
424}
425EXPORT_SYMBOL(mdio_find_bus);
426
427#if IS_ENABLED(CONFIG_OF_MDIO)
428/**
429 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
430 * @mdio_bus_np: Pointer to the mii_bus.
431 *
432 * Returns a reference to the mii_bus, or NULL if none found. The
433 * embedded struct device will have its reference count incremented,
434 * and this must be put once the bus is finished with.
435 *
436 * Because the association of a device_node and mii_bus is made via
437 * of_mdiobus_register(), the mii_bus cannot be found before it is
438 * registered with of_mdiobus_register().
439 *
440 */
441struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
442{
443 struct device *d;
444
445 if (!mdio_bus_np)
446 return NULL;
447
448 d = class_find_device_by_of_node(class: &mdio_bus_class, np: mdio_bus_np);
449 return d ? to_mii_bus(d) : NULL;
450}
451EXPORT_SYMBOL(of_mdio_find_bus);
452
453/* Walk the list of subnodes of a mdio bus and look for a node that
454 * matches the mdio device's address with its 'reg' property. If
455 * found, set the of_node pointer for the mdio device. This allows
456 * auto-probed phy devices to be supplied with information passed in
457 * via DT.
458 */
459static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
460 struct mdio_device *mdiodev)
461{
462 struct device *dev = &mdiodev->dev;
463 struct device_node *child;
464
465 if (dev->of_node || !bus->dev.of_node)
466 return;
467
468 for_each_available_child_of_node(bus->dev.of_node, child) {
469 int addr;
470
471 addr = of_mdio_parse_addr(dev, np: child);
472 if (addr < 0)
473 continue;
474
475 if (addr == mdiodev->addr) {
476 device_set_node(dev, of_fwnode_handle(child));
477 /* The refcount on "child" is passed to the mdio
478 * device. Do _not_ use of_node_put(child) here.
479 */
480 return;
481 }
482 }
483}
484#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
485static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
486 struct mdio_device *mdiodev)
487{
488}
489#endif
490
491/**
492 * mdiobus_create_device - create a full MDIO device given
493 * a mdio_board_info structure
494 * @bus: MDIO bus to create the devices on
495 * @bi: mdio_board_info structure describing the devices
496 *
497 * Returns 0 on success or < 0 on error.
498 */
499static int mdiobus_create_device(struct mii_bus *bus,
500 struct mdio_board_info *bi)
501{
502 struct mdio_device *mdiodev;
503 int ret = 0;
504
505 mdiodev = mdio_device_create(bus, addr: bi->mdio_addr);
506 if (IS_ERR(ptr: mdiodev))
507 return -ENODEV;
508
509 strncpy(p: mdiodev->modalias, q: bi->modalias,
510 size: sizeof(mdiodev->modalias));
511 mdiodev->bus_match = mdio_device_bus_match;
512 mdiodev->dev.platform_data = (void *)bi->platform_data;
513
514 ret = mdio_device_register(mdiodev);
515 if (ret)
516 mdio_device_free(mdiodev);
517
518 return ret;
519}
520
521static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
522{
523 struct phy_device *phydev = ERR_PTR(error: -ENODEV);
524 int err;
525
526 phydev = get_phy_device(bus, addr, is_c45: c45);
527 if (IS_ERR(ptr: phydev))
528 return phydev;
529
530 /* For DT, see if the auto-probed phy has a corresponding child
531 * in the bus node, and set the of_node pointer in this case.
532 */
533 of_mdiobus_link_mdiodev(bus, mdiodev: &phydev->mdio);
534
535 err = phy_device_register(phy: phydev);
536 if (err) {
537 phy_device_free(phydev);
538 return ERR_PTR(error: -ENODEV);
539 }
540
541 return phydev;
542}
543
544/**
545 * mdiobus_scan_c22 - scan one address on a bus for C22 MDIO devices.
546 * @bus: mii_bus to scan
547 * @addr: address on bus to scan
548 *
549 * This function scans one address on the MDIO bus, looking for
550 * devices which can be identified using a vendor/product ID in
551 * registers 2 and 3. Not all MDIO devices have such registers, but
552 * PHY devices typically do. Hence this function assumes anything
553 * found is a PHY, or can be treated as a PHY. Other MDIO devices,
554 * such as switches, will probably not be found during the scan.
555 */
556struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr)
557{
558 return mdiobus_scan(bus, addr, c45: false);
559}
560EXPORT_SYMBOL(mdiobus_scan_c22);
561
562/**
563 * mdiobus_scan_c45 - scan one address on a bus for C45 MDIO devices.
564 * @bus: mii_bus to scan
565 * @addr: address on bus to scan
566 *
567 * This function scans one address on the MDIO bus, looking for
568 * devices which can be identified using a vendor/product ID in
569 * registers 2 and 3. Not all MDIO devices have such registers, but
570 * PHY devices typically do. Hence this function assumes anything
571 * found is a PHY, or can be treated as a PHY. Other MDIO devices,
572 * such as switches, will probably not be found during the scan.
573 */
574static struct phy_device *mdiobus_scan_c45(struct mii_bus *bus, int addr)
575{
576 return mdiobus_scan(bus, addr, c45: true);
577}
578
579static int mdiobus_scan_bus_c22(struct mii_bus *bus)
580{
581 int i;
582
583 for (i = 0; i < PHY_MAX_ADDR; i++) {
584 if ((bus->phy_mask & BIT(i)) == 0) {
585 struct phy_device *phydev;
586
587 phydev = mdiobus_scan_c22(bus, i);
588 if (IS_ERR(ptr: phydev) && (PTR_ERR(ptr: phydev) != -ENODEV))
589 return PTR_ERR(ptr: phydev);
590 }
591 }
592 return 0;
593}
594
595static int mdiobus_scan_bus_c45(struct mii_bus *bus)
596{
597 int i;
598
599 for (i = 0; i < PHY_MAX_ADDR; i++) {
600 if ((bus->phy_mask & BIT(i)) == 0) {
601 struct phy_device *phydev;
602
603 /* Don't scan C45 if we already have a C22 device */
604 if (bus->mdio_map[i])
605 continue;
606
607 phydev = mdiobus_scan_c45(bus, addr: i);
608 if (IS_ERR(ptr: phydev) && (PTR_ERR(ptr: phydev) != -ENODEV))
609 return PTR_ERR(ptr: phydev);
610 }
611 }
612 return 0;
613}
614
615/* There are some C22 PHYs which do bad things when where is a C45
616 * transaction on the bus, like accepting a read themselves, and
617 * stomping over the true devices reply, to performing a write to
618 * themselves which was intended for another device. Now that C22
619 * devices have been found, see if any of them are bad for C45, and if we
620 * should skip the C45 scan.
621 */
622static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
623{
624 int i;
625
626 for (i = 0; i < PHY_MAX_ADDR; i++) {
627 struct phy_device *phydev;
628 u32 oui;
629
630 phydev = mdiobus_get_phy(bus, i);
631 if (!phydev)
632 continue;
633 oui = phydev->phy_id >> 10;
634
635 if (oui == MICREL_OUI)
636 return true;
637 }
638 return false;
639}
640
641/**
642 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
643 * @bus: target mii_bus
644 * @owner: module containing bus accessor functions
645 *
646 * Description: Called by a bus driver to bring up all the PHYs
647 * on a given bus, and attach them to the bus. Drivers should use
648 * mdiobus_register() rather than __mdiobus_register() unless they
649 * need to pass a specific owner module. MDIO devices which are not
650 * PHYs will not be brought up by this function. They are expected
651 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
652 *
653 * Returns 0 on success or < 0 on error.
654 */
655int __mdiobus_register(struct mii_bus *bus, struct module *owner)
656{
657 struct mdio_device *mdiodev;
658 struct gpio_desc *gpiod;
659 bool prevent_c45_scan;
660 int i, err;
661
662 if (!bus || !bus->name)
663 return -EINVAL;
664
665 /* An access method always needs both read and write operations */
666 if (!!bus->read != !!bus->write || !!bus->read_c45 != !!bus->write_c45)
667 return -EINVAL;
668
669 /* At least one method is mandatory */
670 if (!bus->read && !bus->read_c45)
671 return -EINVAL;
672
673 if (bus->parent && bus->parent->of_node)
674 bus->parent->of_node->fwnode.flags |=
675 FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
676
677 WARN(bus->state != MDIOBUS_ALLOCATED &&
678 bus->state != MDIOBUS_UNREGISTERED,
679 "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
680
681 bus->owner = owner;
682 bus->dev.parent = bus->parent;
683 bus->dev.class = &mdio_bus_class;
684 bus->dev.groups = NULL;
685 dev_set_name(dev: &bus->dev, name: "%s", bus->id);
686
687 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
688 * the device in mdiobus_free()
689 *
690 * State will be updated later in this function in case of success
691 */
692 bus->state = MDIOBUS_UNREGISTERED;
693
694 err = device_register(dev: &bus->dev);
695 if (err) {
696 pr_err("mii_bus %s failed to register\n", bus->id);
697 return -EINVAL;
698 }
699
700 mutex_init(&bus->mdio_lock);
701 mutex_init(&bus->shared_lock);
702
703 /* assert bus level PHY GPIO reset */
704 gpiod = devm_gpiod_get_optional(dev: &bus->dev, con_id: "reset", flags: GPIOD_OUT_HIGH);
705 if (IS_ERR(ptr: gpiod)) {
706 err = dev_err_probe(dev: &bus->dev, err: PTR_ERR(ptr: gpiod),
707 fmt: "mii_bus %s couldn't get reset GPIO\n",
708 bus->id);
709 device_del(dev: &bus->dev);
710 return err;
711 } else if (gpiod) {
712 bus->reset_gpiod = gpiod;
713 fsleep(usecs: bus->reset_delay_us);
714 gpiod_set_value_cansleep(desc: gpiod, value: 0);
715 if (bus->reset_post_delay_us > 0)
716 fsleep(usecs: bus->reset_post_delay_us);
717 }
718
719 if (bus->reset) {
720 err = bus->reset(bus);
721 if (err)
722 goto error_reset_gpiod;
723 }
724
725 if (bus->read) {
726 err = mdiobus_scan_bus_c22(bus);
727 if (err)
728 goto error;
729 }
730
731 prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
732
733 if (!prevent_c45_scan && bus->read_c45) {
734 err = mdiobus_scan_bus_c45(bus);
735 if (err)
736 goto error;
737 }
738
739 mdiobus_setup_mdiodev_from_board_info(bus, cb: mdiobus_create_device);
740
741 bus->state = MDIOBUS_REGISTERED;
742 dev_dbg(&bus->dev, "probed\n");
743 return 0;
744
745error:
746 for (i = 0; i < PHY_MAX_ADDR; i++) {
747 mdiodev = bus->mdio_map[i];
748 if (!mdiodev)
749 continue;
750
751 mdiodev->device_remove(mdiodev);
752 mdiodev->device_free(mdiodev);
753 }
754error_reset_gpiod:
755 /* Put PHYs in RESET to save power */
756 if (bus->reset_gpiod)
757 gpiod_set_value_cansleep(desc: bus->reset_gpiod, value: 1);
758
759 device_del(dev: &bus->dev);
760 return err;
761}
762EXPORT_SYMBOL(__mdiobus_register);
763
764void mdiobus_unregister(struct mii_bus *bus)
765{
766 struct mdio_device *mdiodev;
767 int i;
768
769 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
770 return;
771 bus->state = MDIOBUS_UNREGISTERED;
772
773 for (i = 0; i < PHY_MAX_ADDR; i++) {
774 mdiodev = bus->mdio_map[i];
775 if (!mdiodev)
776 continue;
777
778 if (mdiodev->reset_gpio)
779 gpiod_put(desc: mdiodev->reset_gpio);
780
781 mdiodev->device_remove(mdiodev);
782 mdiodev->device_free(mdiodev);
783 }
784
785 /* Put PHYs in RESET to save power */
786 if (bus->reset_gpiod)
787 gpiod_set_value_cansleep(desc: bus->reset_gpiod, value: 1);
788
789 device_del(dev: &bus->dev);
790}
791EXPORT_SYMBOL(mdiobus_unregister);
792
793/**
794 * mdiobus_free - free a struct mii_bus
795 * @bus: mii_bus to free
796 *
797 * This function releases the reference to the underlying device
798 * object in the mii_bus. If this is the last reference, the mii_bus
799 * will be freed.
800 */
801void mdiobus_free(struct mii_bus *bus)
802{
803 /* For compatibility with error handling in drivers. */
804 if (bus->state == MDIOBUS_ALLOCATED) {
805 kfree(objp: bus);
806 return;
807 }
808
809 WARN(bus->state != MDIOBUS_UNREGISTERED,
810 "%s: not in UNREGISTERED state\n", bus->id);
811 bus->state = MDIOBUS_RELEASED;
812
813 put_device(dev: &bus->dev);
814}
815EXPORT_SYMBOL(mdiobus_free);
816
817static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
818{
819 preempt_disable();
820 u64_stats_update_begin(syncp: &stats->syncp);
821
822 u64_stats_inc(p: &stats->transfers);
823 if (ret < 0) {
824 u64_stats_inc(p: &stats->errors);
825 goto out;
826 }
827
828 if (op)
829 u64_stats_inc(p: &stats->reads);
830 else
831 u64_stats_inc(p: &stats->writes);
832out:
833 u64_stats_update_end(syncp: &stats->syncp);
834 preempt_enable();
835}
836
837/**
838 * __mdiobus_read - Unlocked version of the mdiobus_read function
839 * @bus: the mii_bus struct
840 * @addr: the phy address
841 * @regnum: register number to read
842 *
843 * Read a MDIO bus register. Caller must hold the mdio bus lock.
844 *
845 * NOTE: MUST NOT be called from interrupt context.
846 */
847int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
848{
849 int retval;
850
851 lockdep_assert_held_once(&bus->mdio_lock);
852
853 if (bus->read)
854 retval = bus->read(bus, addr, regnum);
855 else
856 retval = -EOPNOTSUPP;
857
858 trace_mdio_access(bus, read: 1, addr, regnum, val: retval, err: retval);
859 mdiobus_stats_acct(stats: &bus->stats[addr], op: true, ret: retval);
860
861 return retval;
862}
863EXPORT_SYMBOL(__mdiobus_read);
864
865/**
866 * __mdiobus_write - Unlocked version of the mdiobus_write function
867 * @bus: the mii_bus struct
868 * @addr: the phy address
869 * @regnum: register number to write
870 * @val: value to write to @regnum
871 *
872 * Write a MDIO bus register. Caller must hold the mdio bus lock.
873 *
874 * NOTE: MUST NOT be called from interrupt context.
875 */
876int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
877{
878 int err;
879
880 lockdep_assert_held_once(&bus->mdio_lock);
881
882 if (bus->write)
883 err = bus->write(bus, addr, regnum, val);
884 else
885 err = -EOPNOTSUPP;
886
887 trace_mdio_access(bus, read: 0, addr, regnum, val, err);
888 mdiobus_stats_acct(stats: &bus->stats[addr], op: false, ret: err);
889
890 return err;
891}
892EXPORT_SYMBOL(__mdiobus_write);
893
894/**
895 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
896 * @bus: the mii_bus struct
897 * @addr: the phy address
898 * @regnum: register number to modify
899 * @mask: bit mask of bits to clear
900 * @set: bit mask of bits to set
901 *
902 * Read, modify, and if any change, write the register value back to the
903 * device. Any error returns a negative number.
904 *
905 * NOTE: MUST NOT be called from interrupt context.
906 */
907int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
908 u16 mask, u16 set)
909{
910 int new, ret;
911
912 ret = __mdiobus_read(bus, addr, regnum);
913 if (ret < 0)
914 return ret;
915
916 new = (ret & ~mask) | set;
917 if (new == ret)
918 return 0;
919
920 ret = __mdiobus_write(bus, addr, regnum, new);
921
922 return ret < 0 ? ret : 1;
923}
924EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
925
926/**
927 * __mdiobus_c45_read - Unlocked version of the mdiobus_c45_read function
928 * @bus: the mii_bus struct
929 * @addr: the phy address
930 * @devad: device address to read
931 * @regnum: register number to read
932 *
933 * Read a MDIO bus register. Caller must hold the mdio bus lock.
934 *
935 * NOTE: MUST NOT be called from interrupt context.
936 */
937int __mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
938{
939 int retval;
940
941 lockdep_assert_held_once(&bus->mdio_lock);
942
943 if (bus->read_c45)
944 retval = bus->read_c45(bus, addr, devad, regnum);
945 else
946 retval = -EOPNOTSUPP;
947
948 trace_mdio_access(bus, read: 1, addr, regnum, val: retval, err: retval);
949 mdiobus_stats_acct(stats: &bus->stats[addr], op: true, ret: retval);
950
951 return retval;
952}
953EXPORT_SYMBOL(__mdiobus_c45_read);
954
955/**
956 * __mdiobus_c45_write - Unlocked version of the mdiobus_write function
957 * @bus: the mii_bus struct
958 * @addr: the phy address
959 * @devad: device address to read
960 * @regnum: register number to write
961 * @val: value to write to @regnum
962 *
963 * Write a MDIO bus register. Caller must hold the mdio bus lock.
964 *
965 * NOTE: MUST NOT be called from interrupt context.
966 */
967int __mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
968 u16 val)
969{
970 int err;
971
972 lockdep_assert_held_once(&bus->mdio_lock);
973
974 if (bus->write_c45)
975 err = bus->write_c45(bus, addr, devad, regnum, val);
976 else
977 err = -EOPNOTSUPP;
978
979 trace_mdio_access(bus, read: 0, addr, regnum, val, err);
980 mdiobus_stats_acct(stats: &bus->stats[addr], op: false, ret: err);
981
982 return err;
983}
984EXPORT_SYMBOL(__mdiobus_c45_write);
985
986/**
987 * __mdiobus_c45_modify_changed - Unlocked version of the mdiobus_modify function
988 * @bus: the mii_bus struct
989 * @addr: the phy address
990 * @devad: device address to read
991 * @regnum: register number to modify
992 * @mask: bit mask of bits to clear
993 * @set: bit mask of bits to set
994 *
995 * Read, modify, and if any change, write the register value back to the
996 * device. Any error returns a negative number.
997 *
998 * NOTE: MUST NOT be called from interrupt context.
999 */
1000static int __mdiobus_c45_modify_changed(struct mii_bus *bus, int addr,
1001 int devad, u32 regnum, u16 mask,
1002 u16 set)
1003{
1004 int new, ret;
1005
1006 ret = __mdiobus_c45_read(bus, addr, devad, regnum);
1007 if (ret < 0)
1008 return ret;
1009
1010 new = (ret & ~mask) | set;
1011 if (new == ret)
1012 return 0;
1013
1014 ret = __mdiobus_c45_write(bus, addr, devad, regnum, new);
1015
1016 return ret < 0 ? ret : 1;
1017}
1018
1019/**
1020 * mdiobus_read_nested - Nested version of the mdiobus_read function
1021 * @bus: the mii_bus struct
1022 * @addr: the phy address
1023 * @regnum: register number to read
1024 *
1025 * In case of nested MDIO bus access avoid lockdep false positives by
1026 * using mutex_lock_nested().
1027 *
1028 * NOTE: MUST NOT be called from interrupt context,
1029 * because the bus read/write functions may wait for an interrupt
1030 * to conclude the operation.
1031 */
1032int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
1033{
1034 int retval;
1035
1036 mutex_lock_nested(lock: &bus->mdio_lock, subclass: MDIO_MUTEX_NESTED);
1037 retval = __mdiobus_read(bus, addr, regnum);
1038 mutex_unlock(lock: &bus->mdio_lock);
1039
1040 return retval;
1041}
1042EXPORT_SYMBOL(mdiobus_read_nested);
1043
1044/**
1045 * mdiobus_read - Convenience function for reading a given MII mgmt register
1046 * @bus: the mii_bus struct
1047 * @addr: the phy address
1048 * @regnum: register number to read
1049 *
1050 * NOTE: MUST NOT be called from interrupt context,
1051 * because the bus read/write functions may wait for an interrupt
1052 * to conclude the operation.
1053 */
1054int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
1055{
1056 int retval;
1057
1058 mutex_lock(&bus->mdio_lock);
1059 retval = __mdiobus_read(bus, addr, regnum);
1060 mutex_unlock(lock: &bus->mdio_lock);
1061
1062 return retval;
1063}
1064EXPORT_SYMBOL(mdiobus_read);
1065
1066/**
1067 * mdiobus_c45_read - Convenience function for reading a given MII mgmt register
1068 * @bus: the mii_bus struct
1069 * @addr: the phy address
1070 * @devad: device address to read
1071 * @regnum: register number to read
1072 *
1073 * NOTE: MUST NOT be called from interrupt context,
1074 * because the bus read/write functions may wait for an interrupt
1075 * to conclude the operation.
1076 */
1077int mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
1078{
1079 int retval;
1080
1081 mutex_lock(&bus->mdio_lock);
1082 retval = __mdiobus_c45_read(bus, addr, devad, regnum);
1083 mutex_unlock(lock: &bus->mdio_lock);
1084
1085 return retval;
1086}
1087EXPORT_SYMBOL(mdiobus_c45_read);
1088
1089/**
1090 * mdiobus_c45_read_nested - Nested version of the mdiobus_c45_read function
1091 * @bus: the mii_bus struct
1092 * @addr: the phy address
1093 * @devad: device address to read
1094 * @regnum: register number to read
1095 *
1096 * In case of nested MDIO bus access avoid lockdep false positives by
1097 * using mutex_lock_nested().
1098 *
1099 * NOTE: MUST NOT be called from interrupt context,
1100 * because the bus read/write functions may wait for an interrupt
1101 * to conclude the operation.
1102 */
1103int mdiobus_c45_read_nested(struct mii_bus *bus, int addr, int devad,
1104 u32 regnum)
1105{
1106 int retval;
1107
1108 mutex_lock_nested(lock: &bus->mdio_lock, subclass: MDIO_MUTEX_NESTED);
1109 retval = __mdiobus_c45_read(bus, addr, devad, regnum);
1110 mutex_unlock(lock: &bus->mdio_lock);
1111
1112 return retval;
1113}
1114EXPORT_SYMBOL(mdiobus_c45_read_nested);
1115
1116/**
1117 * mdiobus_write_nested - Nested version of the mdiobus_write function
1118 * @bus: the mii_bus struct
1119 * @addr: the phy address
1120 * @regnum: register number to write
1121 * @val: value to write to @regnum
1122 *
1123 * In case of nested MDIO bus access avoid lockdep false positives by
1124 * using mutex_lock_nested().
1125 *
1126 * NOTE: MUST NOT be called from interrupt context,
1127 * because the bus read/write functions may wait for an interrupt
1128 * to conclude the operation.
1129 */
1130int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
1131{
1132 int err;
1133
1134 mutex_lock_nested(lock: &bus->mdio_lock, subclass: MDIO_MUTEX_NESTED);
1135 err = __mdiobus_write(bus, addr, regnum, val);
1136 mutex_unlock(lock: &bus->mdio_lock);
1137
1138 return err;
1139}
1140EXPORT_SYMBOL(mdiobus_write_nested);
1141
1142/**
1143 * mdiobus_write - Convenience function for writing a given MII mgmt register
1144 * @bus: the mii_bus struct
1145 * @addr: the phy address
1146 * @regnum: register number to write
1147 * @val: value to write to @regnum
1148 *
1149 * NOTE: MUST NOT be called from interrupt context,
1150 * because the bus read/write functions may wait for an interrupt
1151 * to conclude the operation.
1152 */
1153int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
1154{
1155 int err;
1156
1157 mutex_lock(&bus->mdio_lock);
1158 err = __mdiobus_write(bus, addr, regnum, val);
1159 mutex_unlock(lock: &bus->mdio_lock);
1160
1161 return err;
1162}
1163EXPORT_SYMBOL(mdiobus_write);
1164
1165/**
1166 * mdiobus_c45_write - Convenience function for writing a given MII mgmt register
1167 * @bus: the mii_bus struct
1168 * @addr: the phy address
1169 * @devad: device address to read
1170 * @regnum: register number to write
1171 * @val: value to write to @regnum
1172 *
1173 * NOTE: MUST NOT be called from interrupt context,
1174 * because the bus read/write functions may wait for an interrupt
1175 * to conclude the operation.
1176 */
1177int mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
1178 u16 val)
1179{
1180 int err;
1181
1182 mutex_lock(&bus->mdio_lock);
1183 err = __mdiobus_c45_write(bus, addr, devad, regnum, val);
1184 mutex_unlock(lock: &bus->mdio_lock);
1185
1186 return err;
1187}
1188EXPORT_SYMBOL(mdiobus_c45_write);
1189
1190/**
1191 * mdiobus_c45_write_nested - Nested version of the mdiobus_c45_write function
1192 * @bus: the mii_bus struct
1193 * @addr: the phy address
1194 * @devad: device address to read
1195 * @regnum: register number to write
1196 * @val: value to write to @regnum
1197 *
1198 * In case of nested MDIO bus access avoid lockdep false positives by
1199 * using mutex_lock_nested().
1200 *
1201 * NOTE: MUST NOT be called from interrupt context,
1202 * because the bus read/write functions may wait for an interrupt
1203 * to conclude the operation.
1204 */
1205int mdiobus_c45_write_nested(struct mii_bus *bus, int addr, int devad,
1206 u32 regnum, u16 val)
1207{
1208 int err;
1209
1210 mutex_lock_nested(lock: &bus->mdio_lock, subclass: MDIO_MUTEX_NESTED);
1211 err = __mdiobus_c45_write(bus, addr, devad, regnum, val);
1212 mutex_unlock(lock: &bus->mdio_lock);
1213
1214 return err;
1215}
1216EXPORT_SYMBOL(mdiobus_c45_write_nested);
1217
1218/*
1219 * __mdiobus_modify - Convenience function for modifying a given mdio device
1220 * register
1221 * @bus: the mii_bus struct
1222 * @addr: the phy address
1223 * @regnum: register number to write
1224 * @mask: bit mask of bits to clear
1225 * @set: bit mask of bits to set
1226 */
1227int __mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask,
1228 u16 set)
1229{
1230 int err;
1231
1232 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
1233
1234 return err < 0 ? err : 0;
1235}
1236EXPORT_SYMBOL_GPL(__mdiobus_modify);
1237
1238/**
1239 * mdiobus_modify - Convenience function for modifying a given mdio device
1240 * register
1241 * @bus: the mii_bus struct
1242 * @addr: the phy address
1243 * @regnum: register number to write
1244 * @mask: bit mask of bits to clear
1245 * @set: bit mask of bits to set
1246 */
1247int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
1248{
1249 int err;
1250
1251 mutex_lock(&bus->mdio_lock);
1252 err = __mdiobus_modify(bus, addr, regnum, mask, set);
1253 mutex_unlock(lock: &bus->mdio_lock);
1254
1255 return err;
1256}
1257EXPORT_SYMBOL_GPL(mdiobus_modify);
1258
1259/**
1260 * mdiobus_c45_modify - Convenience function for modifying a given mdio device
1261 * register
1262 * @bus: the mii_bus struct
1263 * @addr: the phy address
1264 * @devad: device address to read
1265 * @regnum: register number to write
1266 * @mask: bit mask of bits to clear
1267 * @set: bit mask of bits to set
1268 */
1269int mdiobus_c45_modify(struct mii_bus *bus, int addr, int devad, u32 regnum,
1270 u16 mask, u16 set)
1271{
1272 int err;
1273
1274 mutex_lock(&bus->mdio_lock);
1275 err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum,
1276 mask, set);
1277 mutex_unlock(lock: &bus->mdio_lock);
1278
1279 return err < 0 ? err : 0;
1280}
1281EXPORT_SYMBOL_GPL(mdiobus_c45_modify);
1282
1283/**
1284 * mdiobus_modify_changed - Convenience function for modifying a given mdio
1285 * device register and returning if it changed
1286 * @bus: the mii_bus struct
1287 * @addr: the phy address
1288 * @regnum: register number to write
1289 * @mask: bit mask of bits to clear
1290 * @set: bit mask of bits to set
1291 */
1292int mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
1293 u16 mask, u16 set)
1294{
1295 int err;
1296
1297 mutex_lock(&bus->mdio_lock);
1298 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
1299 mutex_unlock(lock: &bus->mdio_lock);
1300
1301 return err;
1302}
1303EXPORT_SYMBOL_GPL(mdiobus_modify_changed);
1304
1305/**
1306 * mdiobus_c45_modify_changed - Convenience function for modifying a given mdio
1307 * device register and returning if it changed
1308 * @bus: the mii_bus struct
1309 * @addr: the phy address
1310 * @devad: device address to read
1311 * @regnum: register number to write
1312 * @mask: bit mask of bits to clear
1313 * @set: bit mask of bits to set
1314 */
1315int mdiobus_c45_modify_changed(struct mii_bus *bus, int addr, int devad,
1316 u32 regnum, u16 mask, u16 set)
1317{
1318 int err;
1319
1320 mutex_lock(&bus->mdio_lock);
1321 err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum, mask, set);
1322 mutex_unlock(lock: &bus->mdio_lock);
1323
1324 return err;
1325}
1326EXPORT_SYMBOL_GPL(mdiobus_c45_modify_changed);
1327
1328/**
1329 * mdio_bus_match - determine if given MDIO driver supports the given
1330 * MDIO device
1331 * @dev: target MDIO device
1332 * @drv: given MDIO driver
1333 *
1334 * Description: Given a MDIO device, and a MDIO driver, return 1 if
1335 * the driver supports the device. Otherwise, return 0. This may
1336 * require calling the devices own match function, since different classes
1337 * of MDIO devices have different match criteria.
1338 */
1339static int mdio_bus_match(struct device *dev, struct device_driver *drv)
1340{
1341 struct mdio_driver *mdiodrv = to_mdio_driver(driver: drv);
1342 struct mdio_device *mdio = to_mdio_device(dev);
1343
1344 /* Both the driver and device must type-match */
1345 if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=
1346 !(mdio->flags & MDIO_DEVICE_FLAG_PHY))
1347 return 0;
1348
1349 if (of_driver_match_device(dev, drv))
1350 return 1;
1351
1352 if (mdio->bus_match)
1353 return mdio->bus_match(dev, drv);
1354
1355 return 0;
1356}
1357
1358static int mdio_uevent(const struct device *dev, struct kobj_uevent_env *env)
1359{
1360 int rc;
1361
1362 /* Some devices have extra OF data and an OF-style MODALIAS */
1363 rc = of_device_uevent_modalias(dev, env);
1364 if (rc != -ENODEV)
1365 return rc;
1366
1367 return 0;
1368}
1369
1370static struct attribute *mdio_bus_device_statistics_attrs[] = {
1371 &dev_attr_mdio_bus_device_transfers.attr.attr,
1372 &dev_attr_mdio_bus_device_errors.attr.attr,
1373 &dev_attr_mdio_bus_device_writes.attr.attr,
1374 &dev_attr_mdio_bus_device_reads.attr.attr,
1375 NULL,
1376};
1377
1378static const struct attribute_group mdio_bus_device_statistics_group = {
1379 .name = "statistics",
1380 .attrs = mdio_bus_device_statistics_attrs,
1381};
1382
1383static const struct attribute_group *mdio_bus_dev_groups[] = {
1384 &mdio_bus_device_statistics_group,
1385 NULL,
1386};
1387
1388struct bus_type mdio_bus_type = {
1389 .name = "mdio_bus",
1390 .dev_groups = mdio_bus_dev_groups,
1391 .match = mdio_bus_match,
1392 .uevent = mdio_uevent,
1393};
1394EXPORT_SYMBOL(mdio_bus_type);
1395
1396int __init mdio_bus_init(void)
1397{
1398 int ret;
1399
1400 ret = class_register(class: &mdio_bus_class);
1401 if (!ret) {
1402 ret = bus_register(bus: &mdio_bus_type);
1403 if (ret)
1404 class_unregister(class: &mdio_bus_class);
1405 }
1406
1407 return ret;
1408}
1409
1410#if IS_ENABLED(CONFIG_PHYLIB)
1411void mdio_bus_exit(void)
1412{
1413 class_unregister(class: &mdio_bus_class);
1414 bus_unregister(bus: &mdio_bus_type);
1415}
1416EXPORT_SYMBOL_GPL(mdio_bus_exit);
1417#else
1418module_init(mdio_bus_init);
1419/* no module_exit, intentional */
1420MODULE_LICENSE("GPL");
1421MODULE_DESCRIPTION("MDIO bus/device layer");
1422#endif
1423

source code of linux/drivers/net/phy/mdio_bus.c