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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, const struct device_driver *drv)
1379{
1380 const struct mdio_driver *mdiodrv = to_mdio_driver(drv);
1381 struct mdio_device *mdio = to_mdio_device(dev);
1382
1383 /* Both the driver and device must type-match */
1384 if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=
1385 !(mdio->flags & MDIO_DEVICE_FLAG_PHY))
1386 return 0;
1387
1388 if (of_driver_match_device(dev, drv))
1389 return 1;
1390
1391 if (mdio->bus_match)
1392 return mdio->bus_match(dev, drv);
1393
1394 return 0;
1395}
1396
1397static int mdio_uevent(const struct device *dev, struct kobj_uevent_env *env)
1398{
1399 int rc;
1400
1401 /* Some devices have extra OF data and an OF-style MODALIAS */
1402 rc = of_device_uevent_modalias(dev, env);
1403 if (rc != -ENODEV)
1404 return rc;
1405
1406 return 0;
1407}
1408
1409static struct attribute *mdio_bus_device_statistics_attrs[] = {
1410 &dev_attr_mdio_bus_device_transfers.attr.attr,
1411 &dev_attr_mdio_bus_device_errors.attr.attr,
1412 &dev_attr_mdio_bus_device_writes.attr.attr,
1413 &dev_attr_mdio_bus_device_reads.attr.attr,
1414 NULL,
1415};
1416
1417static const struct attribute_group mdio_bus_device_statistics_group = {
1418 .name = "statistics",
1419 .attrs = mdio_bus_device_statistics_attrs,
1420};
1421
1422static const struct attribute_group *mdio_bus_dev_groups[] = {
1423 &mdio_bus_device_statistics_group,
1424 NULL,
1425};
1426
1427const struct bus_type mdio_bus_type = {
1428 .name = "mdio_bus",
1429 .dev_groups = mdio_bus_dev_groups,
1430 .match = mdio_bus_match,
1431 .uevent = mdio_uevent,
1432};
1433EXPORT_SYMBOL(mdio_bus_type);
1434
1435int __init mdio_bus_init(void)
1436{
1437 int ret;
1438
1439 ret = class_register(&mdio_bus_class);
1440 if (!ret) {
1441 ret = bus_register(&mdio_bus_type);
1442 if (ret)
1443 class_unregister(&mdio_bus_class);
1444 }
1445
1446 return ret;
1447}
1448
1449#if IS_ENABLED(CONFIG_PHYLIB)
1450void mdio_bus_exit(void)
1451{
1452 class_unregister(&mdio_bus_class);
1453 bus_unregister(&mdio_bus_type);
1454}
1455EXPORT_SYMBOL_GPL(mdio_bus_exit);
1456#else
1457module_init(mdio_bus_init);
1458/* no module_exit, intentional */
1459MODULE_LICENSE("GPL");
1460MODULE_DESCRIPTION("MDIO bus/device layer");
1461#endif
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/kernel.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <linux/unistd.h>
15#include <linux/slab.h>
16#include <linux/interrupt.h>
17#include <linux/init.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/gpio.h>
21#include <linux/gpio/consumer.h>
22#include <linux/of_device.h>
23#include <linux/of_mdio.h>
24#include <linux/of_gpio.h>
25#include <linux/netdevice.h>
26#include <linux/etherdevice.h>
27#include <linux/reset.h>
28#include <linux/skbuff.h>
29#include <linux/spinlock.h>
30#include <linux/mm.h>
31#include <linux/module.h>
32#include <linux/mii.h>
33#include <linux/ethtool.h>
34#include <linux/phy.h>
35#include <linux/io.h>
36#include <linux/uaccess.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 int error;
46
47 /* Deassert the optional reset signal */
48 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
49 "reset", GPIOD_OUT_LOW);
50 error = PTR_ERR_OR_ZERO(mdiodev->reset_gpio);
51 if (error)
52 return error;
53
54 if (mdiodev->reset_gpio)
55 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
56
57 return 0;
58}
59
60static int mdiobus_register_reset(struct mdio_device *mdiodev)
61{
62 struct reset_control *reset = NULL;
63
64 if (mdiodev->dev.of_node)
65 reset = devm_reset_control_get_exclusive(&mdiodev->dev,
66 "phy");
67 if (IS_ERR(reset)) {
68 if (PTR_ERR(reset) == -ENOENT || PTR_ERR(reset) == -ENOTSUPP)
69 reset = NULL;
70 else
71 return PTR_ERR(reset);
72 }
73
74 mdiodev->reset_ctrl = reset;
75
76 return 0;
77}
78
79int mdiobus_register_device(struct mdio_device *mdiodev)
80{
81 int err;
82
83 if (mdiodev->bus->mdio_map[mdiodev->addr])
84 return -EBUSY;
85
86 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
87 err = mdiobus_register_gpiod(mdiodev);
88 if (err)
89 return err;
90
91 err = mdiobus_register_reset(mdiodev);
92 if (err)
93 return err;
94
95 /* Assert the reset signal */
96 mdio_device_reset(mdiodev, 1);
97 }
98
99 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
100
101 return 0;
102}
103EXPORT_SYMBOL(mdiobus_register_device);
104
105int mdiobus_unregister_device(struct mdio_device *mdiodev)
106{
107 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
108 return -EINVAL;
109
110 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
111
112 return 0;
113}
114EXPORT_SYMBOL(mdiobus_unregister_device);
115
116struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
117{
118 struct mdio_device *mdiodev = bus->mdio_map[addr];
119
120 if (!mdiodev)
121 return NULL;
122
123 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
124 return NULL;
125
126 return container_of(mdiodev, struct phy_device, mdio);
127}
128EXPORT_SYMBOL(mdiobus_get_phy);
129
130bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
131{
132 return bus->mdio_map[addr];
133}
134EXPORT_SYMBOL(mdiobus_is_registered_device);
135
136/**
137 * mdiobus_alloc_size - allocate a mii_bus structure
138 * @size: extra amount of memory to allocate for private storage.
139 * If non-zero, then bus->priv is points to that memory.
140 *
141 * Description: called by a bus driver to allocate an mii_bus
142 * structure to fill in.
143 */
144struct mii_bus *mdiobus_alloc_size(size_t size)
145{
146 struct mii_bus *bus;
147 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
148 size_t alloc_size;
149 int i;
150
151 /* If we alloc extra space, it should be aligned */
152 if (size)
153 alloc_size = aligned_size + size;
154 else
155 alloc_size = sizeof(*bus);
156
157 bus = kzalloc(alloc_size, GFP_KERNEL);
158 if (!bus)
159 return NULL;
160
161 bus->state = MDIOBUS_ALLOCATED;
162 if (size)
163 bus->priv = (void *)bus + aligned_size;
164
165 /* Initialise the interrupts to polling */
166 for (i = 0; i < PHY_MAX_ADDR; i++)
167 bus->irq[i] = PHY_POLL;
168
169 return bus;
170}
171EXPORT_SYMBOL(mdiobus_alloc_size);
172
173static void _devm_mdiobus_free(struct device *dev, void *res)
174{
175 mdiobus_free(*(struct mii_bus **)res);
176}
177
178static int devm_mdiobus_match(struct device *dev, void *res, void *data)
179{
180 struct mii_bus **r = res;
181
182 if (WARN_ON(!r || !*r))
183 return 0;
184
185 return *r == data;
186}
187
188/**
189 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
190 * @dev: Device to allocate mii_bus for
191 * @sizeof_priv: Space to allocate for private structure.
192 *
193 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
194 * automatically freed on driver detach.
195 *
196 * If an mii_bus allocated with this function needs to be freed separately,
197 * devm_mdiobus_free() must be used.
198 *
199 * RETURNS:
200 * Pointer to allocated mii_bus on success, NULL on failure.
201 */
202struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
203{
204 struct mii_bus **ptr, *bus;
205
206 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
207 if (!ptr)
208 return NULL;
209
210 /* use raw alloc_dr for kmalloc caller tracing */
211 bus = mdiobus_alloc_size(sizeof_priv);
212 if (bus) {
213 *ptr = bus;
214 devres_add(dev, ptr);
215 } else {
216 devres_free(ptr);
217 }
218
219 return bus;
220}
221EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
222
223/**
224 * devm_mdiobus_free - Resource-managed mdiobus_free()
225 * @dev: Device this mii_bus belongs to
226 * @bus: the mii_bus associated with the device
227 *
228 * Free mii_bus allocated with devm_mdiobus_alloc_size().
229 */
230void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
231{
232 int rc;
233
234 rc = devres_release(dev, _devm_mdiobus_free,
235 devm_mdiobus_match, bus);
236 WARN_ON(rc);
237}
238EXPORT_SYMBOL_GPL(devm_mdiobus_free);
239
240/**
241 * mdiobus_release - mii_bus device release callback
242 * @d: the target struct device that contains the mii_bus
243 *
244 * Description: called when the last reference to an mii_bus is
245 * dropped, to free the underlying memory.
246 */
247static void mdiobus_release(struct device *d)
248{
249 struct mii_bus *bus = to_mii_bus(d);
250 BUG_ON(bus->state != MDIOBUS_RELEASED &&
251 /* for compatibility with error handling in drivers */
252 bus->state != MDIOBUS_ALLOCATED);
253 kfree(bus);
254}
255
256static struct class mdio_bus_class = {
257 .name = "mdio_bus",
258 .dev_release = mdiobus_release,
259};
260
261#if IS_ENABLED(CONFIG_OF_MDIO)
262/**
263 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
264 * @mdio_bus_np: Pointer to the mii_bus.
265 *
266 * Returns a reference to the mii_bus, or NULL if none found. The
267 * embedded struct device will have its reference count incremented,
268 * and this must be put once the bus is finished with.
269 *
270 * Because the association of a device_node and mii_bus is made via
271 * of_mdiobus_register(), the mii_bus cannot be found before it is
272 * registered with of_mdiobus_register().
273 *
274 */
275struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
276{
277 struct device *d;
278
279 if (!mdio_bus_np)
280 return NULL;
281
282 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
283 return d ? to_mii_bus(d) : NULL;
284}
285EXPORT_SYMBOL(of_mdio_find_bus);
286
287/* Walk the list of subnodes of a mdio bus and look for a node that
288 * matches the mdio device's address with its 'reg' property. If
289 * found, set the of_node pointer for the mdio device. This allows
290 * auto-probed phy devices to be supplied with information passed in
291 * via DT.
292 */
293static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
294 struct mdio_device *mdiodev)
295{
296 struct device *dev = &mdiodev->dev;
297 struct device_node *child;
298
299 if (dev->of_node || !bus->dev.of_node)
300 return;
301
302 for_each_available_child_of_node(bus->dev.of_node, child) {
303 int addr;
304
305 addr = of_mdio_parse_addr(dev, child);
306 if (addr < 0)
307 continue;
308
309 if (addr == mdiodev->addr) {
310 dev->of_node = child;
311 dev->fwnode = of_fwnode_handle(child);
312 return;
313 }
314 }
315}
316#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
317static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
318 struct mdio_device *mdiodev)
319{
320}
321#endif
322
323/**
324 * mdiobus_create_device_from_board_info - create a full MDIO device given
325 * a mdio_board_info structure
326 * @bus: MDIO bus to create the devices on
327 * @bi: mdio_board_info structure describing the devices
328 *
329 * Returns 0 on success or < 0 on error.
330 */
331static int mdiobus_create_device(struct mii_bus *bus,
332 struct mdio_board_info *bi)
333{
334 struct mdio_device *mdiodev;
335 int ret = 0;
336
337 mdiodev = mdio_device_create(bus, bi->mdio_addr);
338 if (IS_ERR(mdiodev))
339 return -ENODEV;
340
341 strncpy(mdiodev->modalias, bi->modalias,
342 sizeof(mdiodev->modalias));
343 mdiodev->bus_match = mdio_device_bus_match;
344 mdiodev->dev.platform_data = (void *)bi->platform_data;
345
346 ret = mdio_device_register(mdiodev);
347 if (ret)
348 mdio_device_free(mdiodev);
349
350 return ret;
351}
352
353/**
354 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
355 * @bus: target mii_bus
356 * @owner: module containing bus accessor functions
357 *
358 * Description: Called by a bus driver to bring up all the PHYs
359 * on a given bus, and attach them to the bus. Drivers should use
360 * mdiobus_register() rather than __mdiobus_register() unless they
361 * need to pass a specific owner module. MDIO devices which are not
362 * PHYs will not be brought up by this function. They are expected to
363 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
364 *
365 * Returns 0 on success or < 0 on error.
366 */
367int __mdiobus_register(struct mii_bus *bus, struct module *owner)
368{
369 struct mdio_device *mdiodev;
370 int i, err;
371 struct gpio_desc *gpiod;
372
373 if (NULL == bus || NULL == bus->name ||
374 NULL == bus->read || NULL == bus->write)
375 return -EINVAL;
376
377 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
378 bus->state != MDIOBUS_UNREGISTERED);
379
380 bus->owner = owner;
381 bus->dev.parent = bus->parent;
382 bus->dev.class = &mdio_bus_class;
383 bus->dev.groups = NULL;
384 dev_set_name(&bus->dev, "%s", bus->id);
385
386 err = device_register(&bus->dev);
387 if (err) {
388 pr_err("mii_bus %s failed to register\n", bus->id);
389 return -EINVAL;
390 }
391
392 mutex_init(&bus->mdio_lock);
393
394 /* de-assert bus level PHY GPIO reset */
395 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
396 if (IS_ERR(gpiod)) {
397 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
398 bus->id);
399 device_del(&bus->dev);
400 return PTR_ERR(gpiod);
401 } else if (gpiod) {
402 bus->reset_gpiod = gpiod;
403
404 gpiod_set_value_cansleep(gpiod, 1);
405 udelay(bus->reset_delay_us);
406 gpiod_set_value_cansleep(gpiod, 0);
407 }
408
409 if (bus->reset)
410 bus->reset(bus);
411
412 for (i = 0; i < PHY_MAX_ADDR; i++) {
413 if ((bus->phy_mask & (1 << i)) == 0) {
414 struct phy_device *phydev;
415
416 phydev = mdiobus_scan(bus, i);
417 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
418 err = PTR_ERR(phydev);
419 goto error;
420 }
421 }
422 }
423
424 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
425
426 bus->state = MDIOBUS_REGISTERED;
427 pr_info("%s: probed\n", bus->name);
428 return 0;
429
430error:
431 while (--i >= 0) {
432 mdiodev = bus->mdio_map[i];
433 if (!mdiodev)
434 continue;
435
436 mdiodev->device_remove(mdiodev);
437 mdiodev->device_free(mdiodev);
438 }
439
440 /* Put PHYs in RESET to save power */
441 if (bus->reset_gpiod)
442 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
443
444 device_del(&bus->dev);
445 return err;
446}
447EXPORT_SYMBOL(__mdiobus_register);
448
449void mdiobus_unregister(struct mii_bus *bus)
450{
451 struct mdio_device *mdiodev;
452 int i;
453
454 BUG_ON(bus->state != MDIOBUS_REGISTERED);
455 bus->state = MDIOBUS_UNREGISTERED;
456
457 for (i = 0; i < PHY_MAX_ADDR; i++) {
458 mdiodev = bus->mdio_map[i];
459 if (!mdiodev)
460 continue;
461
462 if (mdiodev->reset_gpio)
463 gpiod_put(mdiodev->reset_gpio);
464
465 mdiodev->device_remove(mdiodev);
466 mdiodev->device_free(mdiodev);
467 }
468
469 /* Put PHYs in RESET to save power */
470 if (bus->reset_gpiod)
471 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
472
473 device_del(&bus->dev);
474}
475EXPORT_SYMBOL(mdiobus_unregister);
476
477/**
478 * mdiobus_free - free a struct mii_bus
479 * @bus: mii_bus to free
480 *
481 * This function releases the reference to the underlying device
482 * object in the mii_bus. If this is the last reference, the mii_bus
483 * will be freed.
484 */
485void mdiobus_free(struct mii_bus *bus)
486{
487 /* For compatibility with error handling in drivers. */
488 if (bus->state == MDIOBUS_ALLOCATED) {
489 kfree(bus);
490 return;
491 }
492
493 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
494 bus->state = MDIOBUS_RELEASED;
495
496 put_device(&bus->dev);
497}
498EXPORT_SYMBOL(mdiobus_free);
499
500/**
501 * mdiobus_scan - scan a bus for MDIO devices.
502 * @bus: mii_bus to scan
503 * @addr: address on bus to scan
504 *
505 * This function scans the MDIO bus, looking for devices which can be
506 * identified using a vendor/product ID in registers 2 and 3. Not all
507 * MDIO devices have such registers, but PHY devices typically
508 * do. Hence this function assumes anything found is a PHY, or can be
509 * treated as a PHY. Other MDIO devices, such as switches, will
510 * probably not be found during the scan.
511 */
512struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
513{
514 struct phy_device *phydev;
515 int err;
516
517 phydev = get_phy_device(bus, addr, false);
518 if (IS_ERR(phydev))
519 return phydev;
520
521 /*
522 * For DT, see if the auto-probed phy has a correspoding child
523 * in the bus node, and set the of_node pointer in this case.
524 */
525 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
526
527 err = phy_device_register(phydev);
528 if (err) {
529 phy_device_free(phydev);
530 return ERR_PTR(-ENODEV);
531 }
532
533 return phydev;
534}
535EXPORT_SYMBOL(mdiobus_scan);
536
537/**
538 * __mdiobus_read - Unlocked version of the mdiobus_read function
539 * @bus: the mii_bus struct
540 * @addr: the phy address
541 * @regnum: register number to read
542 *
543 * Read a MDIO bus register. Caller must hold the mdio bus lock.
544 *
545 * NOTE: MUST NOT be called from interrupt context.
546 */
547int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
548{
549 int retval;
550
551 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
552
553 retval = bus->read(bus, addr, regnum);
554
555 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
556
557 return retval;
558}
559EXPORT_SYMBOL(__mdiobus_read);
560
561/**
562 * __mdiobus_write - Unlocked version of the mdiobus_write function
563 * @bus: the mii_bus struct
564 * @addr: the phy address
565 * @regnum: register number to write
566 * @val: value to write to @regnum
567 *
568 * Write a MDIO bus register. Caller must hold the mdio bus lock.
569 *
570 * NOTE: MUST NOT be called from interrupt context.
571 */
572int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
573{
574 int err;
575
576 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
577
578 err = bus->write(bus, addr, regnum, val);
579
580 trace_mdio_access(bus, 0, addr, regnum, val, err);
581
582 return err;
583}
584EXPORT_SYMBOL(__mdiobus_write);
585
586/**
587 * mdiobus_read_nested - Nested version of the mdiobus_read function
588 * @bus: the mii_bus struct
589 * @addr: the phy address
590 * @regnum: register number to read
591 *
592 * In case of nested MDIO bus access avoid lockdep false positives by
593 * using mutex_lock_nested().
594 *
595 * NOTE: MUST NOT be called from interrupt context,
596 * because the bus read/write functions may wait for an interrupt
597 * to conclude the operation.
598 */
599int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
600{
601 int retval;
602
603 BUG_ON(in_interrupt());
604
605 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
606 retval = __mdiobus_read(bus, addr, regnum);
607 mutex_unlock(&bus->mdio_lock);
608
609 return retval;
610}
611EXPORT_SYMBOL(mdiobus_read_nested);
612
613/**
614 * mdiobus_read - Convenience function for reading a given MII mgmt register
615 * @bus: the mii_bus struct
616 * @addr: the phy address
617 * @regnum: register number to read
618 *
619 * NOTE: MUST NOT be called from interrupt context,
620 * because the bus read/write functions may wait for an interrupt
621 * to conclude the operation.
622 */
623int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
624{
625 int retval;
626
627 BUG_ON(in_interrupt());
628
629 mutex_lock(&bus->mdio_lock);
630 retval = __mdiobus_read(bus, addr, regnum);
631 mutex_unlock(&bus->mdio_lock);
632
633 return retval;
634}
635EXPORT_SYMBOL(mdiobus_read);
636
637/**
638 * mdiobus_write_nested - Nested version of the mdiobus_write function
639 * @bus: the mii_bus struct
640 * @addr: the phy address
641 * @regnum: register number to write
642 * @val: value to write to @regnum
643 *
644 * In case of nested MDIO bus access avoid lockdep false positives by
645 * using mutex_lock_nested().
646 *
647 * NOTE: MUST NOT be called from interrupt context,
648 * because the bus read/write functions may wait for an interrupt
649 * to conclude the operation.
650 */
651int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
652{
653 int err;
654
655 BUG_ON(in_interrupt());
656
657 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
658 err = __mdiobus_write(bus, addr, regnum, val);
659 mutex_unlock(&bus->mdio_lock);
660
661 return err;
662}
663EXPORT_SYMBOL(mdiobus_write_nested);
664
665/**
666 * mdiobus_write - Convenience function for writing a given MII mgmt register
667 * @bus: the mii_bus struct
668 * @addr: the phy address
669 * @regnum: register number to write
670 * @val: value to write to @regnum
671 *
672 * NOTE: MUST NOT be called from interrupt context,
673 * because the bus read/write functions may wait for an interrupt
674 * to conclude the operation.
675 */
676int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
677{
678 int err;
679
680 BUG_ON(in_interrupt());
681
682 mutex_lock(&bus->mdio_lock);
683 err = __mdiobus_write(bus, addr, regnum, val);
684 mutex_unlock(&bus->mdio_lock);
685
686 return err;
687}
688EXPORT_SYMBOL(mdiobus_write);
689
690/**
691 * mdio_bus_match - determine if given MDIO driver supports the given
692 * MDIO device
693 * @dev: target MDIO device
694 * @drv: given MDIO driver
695 *
696 * Description: Given a MDIO device, and a MDIO driver, return 1 if
697 * the driver supports the device. Otherwise, return 0. This may
698 * require calling the devices own match function, since different classes
699 * of MDIO devices have different match criteria.
700 */
701static int mdio_bus_match(struct device *dev, struct device_driver *drv)
702{
703 struct mdio_device *mdio = to_mdio_device(dev);
704
705 if (of_driver_match_device(dev, drv))
706 return 1;
707
708 if (mdio->bus_match)
709 return mdio->bus_match(dev, drv);
710
711 return 0;
712}
713
714static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
715{
716 int rc;
717
718 /* Some devices have extra OF data and an OF-style MODALIAS */
719 rc = of_device_uevent_modalias(dev, env);
720 if (rc != -ENODEV)
721 return rc;
722
723 return 0;
724}
725
726struct bus_type mdio_bus_type = {
727 .name = "mdio_bus",
728 .match = mdio_bus_match,
729 .uevent = mdio_uevent,
730};
731EXPORT_SYMBOL(mdio_bus_type);
732
733int __init mdio_bus_init(void)
734{
735 int ret;
736
737 ret = class_register(&mdio_bus_class);
738 if (!ret) {
739 ret = bus_register(&mdio_bus_type);
740 if (ret)
741 class_unregister(&mdio_bus_class);
742 }
743
744 return ret;
745}
746EXPORT_SYMBOL_GPL(mdio_bus_init);
747
748#if IS_ENABLED(CONFIG_PHYLIB)
749void mdio_bus_exit(void)
750{
751 class_unregister(&mdio_bus_class);
752 bus_unregister(&mdio_bus_type);
753}
754EXPORT_SYMBOL_GPL(mdio_bus_exit);
755#else
756module_init(mdio_bus_init);
757/* no module_exit, intentional */
758MODULE_LICENSE("GPL");
759MODULE_DESCRIPTION("MDIO bus/device layer");
760#endif