1 // SPDX-License-Identifier: GPL-2.0+
2 /* MDIO Bus interface
3 *
4 * Author: Andy Fleming
5 *
6 * Copyright (c) 2004 Freescale Semiconductor, Inc.
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/errno.h>
14 #include <linux/etherdevice.h>
15 #include <linux/ethtool.h>
16 #include <linux/gpio.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/mii.h>
23 #include <linux/mm.h>
24 #include <linux/module.h>
25 #include <linux/netdevice.h>
26 #include <linux/of_device.h>
27 #include <linux/of_gpio.h>
28 #include <linux/of_mdio.h>
29 #include <linux/phy.h>
30 #include <linux/reset.h>
31 #include <linux/skbuff.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34 #include <linux/string.h>
35 #include <linux/uaccess.h>
36 #include <linux/unistd.h>
37
38 #define CREATE_TRACE_POINTS
39 #include <trace/events/mdio.h>
40
41 #include "mdio-boardinfo.h"
42
mdiobus_register_gpiod(struct mdio_device * mdiodev)43 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
44 {
45 /* Deassert the optional reset signal */
46 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
47 "reset", GPIOD_OUT_LOW);
48 if (IS_ERR(mdiodev->reset_gpio))
49 return PTR_ERR(mdiodev->reset_gpio);
50
51 if (mdiodev->reset_gpio)
52 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
53
54 return 0;
55 }
56
mdiobus_register_reset(struct mdio_device * mdiodev)57 static int mdiobus_register_reset(struct mdio_device *mdiodev)
58 {
59 struct reset_control *reset;
60
61 reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
62 if (IS_ERR(reset))
63 return PTR_ERR(reset);
64
65 mdiodev->reset_ctrl = reset;
66
67 return 0;
68 }
69
mdiobus_register_device(struct mdio_device * mdiodev)70 int mdiobus_register_device(struct mdio_device *mdiodev)
71 {
72 int err;
73
74 if (mdiodev->bus->mdio_map[mdiodev->addr])
75 return -EBUSY;
76
77 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
78 err = mdiobus_register_gpiod(mdiodev);
79 if (err)
80 return err;
81
82 err = mdiobus_register_reset(mdiodev);
83 if (err)
84 return err;
85
86 /* Assert the reset signal */
87 mdio_device_reset(mdiodev, 1);
88 }
89
90 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
91
92 return 0;
93 }
94 EXPORT_SYMBOL(mdiobus_register_device);
95
mdiobus_unregister_device(struct mdio_device * mdiodev)96 int mdiobus_unregister_device(struct mdio_device *mdiodev)
97 {
98 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
99 return -EINVAL;
100
101 reset_control_put(mdiodev->reset_ctrl);
102
103 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
104
105 return 0;
106 }
107 EXPORT_SYMBOL(mdiobus_unregister_device);
108
mdiobus_get_phy(struct mii_bus * bus,int addr)109 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
110 {
111 struct mdio_device *mdiodev = bus->mdio_map[addr];
112
113 if (!mdiodev)
114 return NULL;
115
116 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
117 return NULL;
118
119 return container_of(mdiodev, struct phy_device, mdio);
120 }
121 EXPORT_SYMBOL(mdiobus_get_phy);
122
mdiobus_is_registered_device(struct mii_bus * bus,int addr)123 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
124 {
125 return bus->mdio_map[addr];
126 }
127 EXPORT_SYMBOL(mdiobus_is_registered_device);
128
129 /**
130 * mdiobus_alloc_size - allocate a mii_bus structure
131 * @size: extra amount of memory to allocate for private storage.
132 * If non-zero, then bus->priv is points to that memory.
133 *
134 * Description: called by a bus driver to allocate an mii_bus
135 * structure to fill in.
136 */
mdiobus_alloc_size(size_t size)137 struct mii_bus *mdiobus_alloc_size(size_t size)
138 {
139 struct mii_bus *bus;
140 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
141 size_t alloc_size;
142 int i;
143
144 /* If we alloc extra space, it should be aligned */
145 if (size)
146 alloc_size = aligned_size + size;
147 else
148 alloc_size = sizeof(*bus);
149
150 bus = kzalloc(alloc_size, GFP_KERNEL);
151 if (!bus)
152 return NULL;
153
154 bus->state = MDIOBUS_ALLOCATED;
155 if (size)
156 bus->priv = (void *)bus + aligned_size;
157
158 /* Initialise the interrupts to polling and 64-bit seqcounts */
159 for (i = 0; i < PHY_MAX_ADDR; i++) {
160 bus->irq[i] = PHY_POLL;
161 u64_stats_init(&bus->stats[i].syncp);
162 }
163
164 return bus;
165 }
166 EXPORT_SYMBOL(mdiobus_alloc_size);
167
168 /**
169 * mdiobus_release - mii_bus device release callback
170 * @d: the target struct device that contains the mii_bus
171 *
172 * Description: called when the last reference to an mii_bus is
173 * dropped, to free the underlying memory.
174 */
mdiobus_release(struct device * d)175 static void mdiobus_release(struct device *d)
176 {
177 struct mii_bus *bus = to_mii_bus(d);
178
179 WARN(bus->state != MDIOBUS_RELEASED &&
180 /* for compatibility with error handling in drivers */
181 bus->state != MDIOBUS_ALLOCATED,
182 "%s: not in RELEASED or ALLOCATED state\n",
183 bus->id);
184 kfree(bus);
185 }
186
187 struct mdio_bus_stat_attr {
188 int addr;
189 unsigned int field_offset;
190 };
191
mdio_bus_get_stat(struct mdio_bus_stats * s,unsigned int offset)192 static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
193 {
194 const char *p = (const char *)s + offset;
195 unsigned int start;
196 u64 val = 0;
197
198 do {
199 start = u64_stats_fetch_begin(&s->syncp);
200 val = u64_stats_read((const u64_stats_t *)p);
201 } while (u64_stats_fetch_retry(&s->syncp, start));
202
203 return val;
204 }
205
mdio_bus_get_global_stat(struct mii_bus * bus,unsigned int offset)206 static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
207 {
208 unsigned int i;
209 u64 val = 0;
210
211 for (i = 0; i < PHY_MAX_ADDR; i++)
212 val += mdio_bus_get_stat(&bus->stats[i], offset);
213
214 return val;
215 }
216
mdio_bus_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)217 static ssize_t mdio_bus_stat_field_show(struct device *dev,
218 struct device_attribute *attr,
219 char *buf)
220 {
221 struct mii_bus *bus = to_mii_bus(dev);
222 struct mdio_bus_stat_attr *sattr;
223 struct dev_ext_attribute *eattr;
224 u64 val;
225
226 eattr = container_of(attr, struct dev_ext_attribute, attr);
227 sattr = eattr->var;
228
229 if (sattr->addr < 0)
230 val = mdio_bus_get_global_stat(bus, sattr->field_offset);
231 else
232 val = mdio_bus_get_stat(&bus->stats[sattr->addr],
233 sattr->field_offset);
234
235 return sprintf(buf, "%llu\n", val);
236 }
237
mdio_bus_device_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)238 static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
239 struct device_attribute *attr,
240 char *buf)
241 {
242 struct mdio_device *mdiodev = to_mdio_device(dev);
243 struct mii_bus *bus = mdiodev->bus;
244 struct mdio_bus_stat_attr *sattr;
245 struct dev_ext_attribute *eattr;
246 int addr = mdiodev->addr;
247 u64 val;
248
249 eattr = container_of(attr, struct dev_ext_attribute, attr);
250 sattr = eattr->var;
251
252 val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);
253
254 return sprintf(buf, "%llu\n", val);
255 }
256
257 #define MDIO_BUS_STATS_ATTR_DECL(field, file) \
258 static struct dev_ext_attribute dev_attr_mdio_bus_##field = { \
259 .attr = { .attr = { .name = file, .mode = 0444 }, \
260 .show = mdio_bus_stat_field_show, \
261 }, \
262 .var = &((struct mdio_bus_stat_attr) { \
263 -1, offsetof(struct mdio_bus_stats, field) \
264 }), \
265 }; \
266 static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = { \
267 .attr = { .attr = { .name = file, .mode = 0444 }, \
268 .show = mdio_bus_device_stat_field_show, \
269 }, \
270 .var = &((struct mdio_bus_stat_attr) { \
271 -1, offsetof(struct mdio_bus_stats, field) \
272 }), \
273 };
274
275 #define MDIO_BUS_STATS_ATTR(field) \
276 MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
277
278 MDIO_BUS_STATS_ATTR(transfers);
279 MDIO_BUS_STATS_ATTR(errors);
280 MDIO_BUS_STATS_ATTR(writes);
281 MDIO_BUS_STATS_ATTR(reads);
282
283 #define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file) \
284 static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \
285 .attr = { .attr = { .name = file, .mode = 0444 }, \
286 .show = mdio_bus_stat_field_show, \
287 }, \
288 .var = &((struct mdio_bus_stat_attr) { \
289 addr, offsetof(struct mdio_bus_stats, field) \
290 }), \
291 }
292
293 #define MDIO_BUS_STATS_ADDR_ATTR(field, addr) \
294 MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, \
295 __stringify(field) "_" __stringify(addr))
296
297 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr) \
298 MDIO_BUS_STATS_ADDR_ATTR(transfers, addr); \
299 MDIO_BUS_STATS_ADDR_ATTR(errors, addr); \
300 MDIO_BUS_STATS_ADDR_ATTR(writes, addr); \
301 MDIO_BUS_STATS_ADDR_ATTR(reads, addr) \
302
303 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
304 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
305 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
306 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
307 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
308 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
309 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
310 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
311 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
312 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
313 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
314 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
315 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
316 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
317 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
318 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
319 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
320 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
321 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
322 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
323 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
324 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
325 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
326 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
327 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
328 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
329 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
330 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
331 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
332 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
333 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
334 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
335
336 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr) \
337 &dev_attr_mdio_bus_addr_transfers_##addr.attr.attr, \
338 &dev_attr_mdio_bus_addr_errors_##addr.attr.attr, \
339 &dev_attr_mdio_bus_addr_writes_##addr.attr.attr, \
340 &dev_attr_mdio_bus_addr_reads_##addr.attr.attr \
341
342 static struct attribute *mdio_bus_statistics_attrs[] = {
343 &dev_attr_mdio_bus_transfers.attr.attr,
344 &dev_attr_mdio_bus_errors.attr.attr,
345 &dev_attr_mdio_bus_writes.attr.attr,
346 &dev_attr_mdio_bus_reads.attr.attr,
347 MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),
348 MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),
349 MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),
350 MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),
351 MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),
352 MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),
353 MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),
354 MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),
355 MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),
356 MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),
357 MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),
358 MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),
359 MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),
360 MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),
361 MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),
362 MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),
363 MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),
364 MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),
365 MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),
366 MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),
367 MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),
368 MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),
369 MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),
370 MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),
371 MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),
372 MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),
373 MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),
374 MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),
375 MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),
376 MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),
377 MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),
378 MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),
379 NULL,
380 };
381
382 static const struct attribute_group mdio_bus_statistics_group = {
383 .name = "statistics",
384 .attrs = mdio_bus_statistics_attrs,
385 };
386
387 static const struct attribute_group *mdio_bus_groups[] = {
388 &mdio_bus_statistics_group,
389 NULL,
390 };
391
392 static struct class mdio_bus_class = {
393 .name = "mdio_bus",
394 .dev_release = mdiobus_release,
395 .dev_groups = mdio_bus_groups,
396 };
397
398 /**
399 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
400 * @mdio_name: The name of a mdiobus.
401 *
402 * Returns a reference to the mii_bus, or NULL if none found. The
403 * embedded struct device will have its reference count incremented,
404 * and this must be put_deviced'ed once the bus is finished with.
405 */
mdio_find_bus(const char * mdio_name)406 struct mii_bus *mdio_find_bus(const char *mdio_name)
407 {
408 struct device *d;
409
410 d = class_find_device_by_name(&mdio_bus_class, mdio_name);
411 return d ? to_mii_bus(d) : NULL;
412 }
413 EXPORT_SYMBOL(mdio_find_bus);
414
415 #if IS_ENABLED(CONFIG_OF_MDIO)
416 /**
417 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
418 * @mdio_bus_np: Pointer to the mii_bus.
419 *
420 * Returns a reference to the mii_bus, or NULL if none found. The
421 * embedded struct device will have its reference count incremented,
422 * and this must be put once the bus is finished with.
423 *
424 * Because the association of a device_node and mii_bus is made via
425 * of_mdiobus_register(), the mii_bus cannot be found before it is
426 * registered with of_mdiobus_register().
427 *
428 */
of_mdio_find_bus(struct device_node * mdio_bus_np)429 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
430 {
431 struct device *d;
432
433 if (!mdio_bus_np)
434 return NULL;
435
436 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
437 return d ? to_mii_bus(d) : NULL;
438 }
439 EXPORT_SYMBOL(of_mdio_find_bus);
440
441 /* Walk the list of subnodes of a mdio bus and look for a node that
442 * matches the mdio device's address with its 'reg' property. If
443 * found, set the of_node pointer for the mdio device. This allows
444 * auto-probed phy devices to be supplied with information passed in
445 * via DT.
446 */
of_mdiobus_link_mdiodev(struct mii_bus * bus,struct mdio_device * mdiodev)447 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
448 struct mdio_device *mdiodev)
449 {
450 struct device *dev = &mdiodev->dev;
451 struct device_node *child;
452
453 if (dev->of_node || !bus->dev.of_node)
454 return;
455
456 for_each_available_child_of_node(bus->dev.of_node, child) {
457 int addr;
458
459 addr = of_mdio_parse_addr(dev, child);
460 if (addr < 0)
461 continue;
462
463 if (addr == mdiodev->addr) {
464 device_set_node(dev, of_fwnode_handle(child));
465 /* The refcount on "child" is passed to the mdio
466 * device. Do _not_ use of_node_put(child) here.
467 */
468 return;
469 }
470 }
471 }
472 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
of_mdiobus_link_mdiodev(struct mii_bus * mdio,struct mdio_device * mdiodev)473 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
474 struct mdio_device *mdiodev)
475 {
476 }
477 #endif
478
479 /**
480 * mdiobus_create_device - create a full MDIO device given
481 * a mdio_board_info structure
482 * @bus: MDIO bus to create the devices on
483 * @bi: mdio_board_info structure describing the devices
484 *
485 * Returns 0 on success or < 0 on error.
486 */
mdiobus_create_device(struct mii_bus * bus,struct mdio_board_info * bi)487 static int mdiobus_create_device(struct mii_bus *bus,
488 struct mdio_board_info *bi)
489 {
490 struct mdio_device *mdiodev;
491 int ret = 0;
492
493 mdiodev = mdio_device_create(bus, bi->mdio_addr);
494 if (IS_ERR(mdiodev))
495 return -ENODEV;
496
497 strncpy(mdiodev->modalias, bi->modalias,
498 sizeof(mdiodev->modalias));
499 mdiodev->bus_match = mdio_device_bus_match;
500 mdiodev->dev.platform_data = (void *)bi->platform_data;
501
502 ret = mdio_device_register(mdiodev);
503 if (ret)
504 mdio_device_free(mdiodev);
505
506 return ret;
507 }
508
509 /**
510 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
511 * @bus: target mii_bus
512 * @owner: module containing bus accessor functions
513 *
514 * Description: Called by a bus driver to bring up all the PHYs
515 * on a given bus, and attach them to the bus. Drivers should use
516 * mdiobus_register() rather than __mdiobus_register() unless they
517 * need to pass a specific owner module. MDIO devices which are not
518 * PHYs will not be brought up by this function. They are expected
519 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
520 *
521 * Returns 0 on success or < 0 on error.
522 */
__mdiobus_register(struct mii_bus * bus,struct module * owner)523 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
524 {
525 struct mdio_device *mdiodev;
526 int i, err;
527 struct gpio_desc *gpiod;
528
529 if (NULL == bus || NULL == bus->name ||
530 NULL == bus->read || NULL == bus->write)
531 return -EINVAL;
532
533 if (bus->parent && bus->parent->of_node)
534 bus->parent->of_node->fwnode.flags |=
535 FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
536
537 WARN(bus->state != MDIOBUS_ALLOCATED &&
538 bus->state != MDIOBUS_UNREGISTERED,
539 "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
540
541 bus->owner = owner;
542 bus->dev.parent = bus->parent;
543 bus->dev.class = &mdio_bus_class;
544 bus->dev.groups = NULL;
545 dev_set_name(&bus->dev, "%s", bus->id);
546
547 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
548 * the device in mdiobus_free()
549 *
550 * State will be updated later in this function in case of success
551 */
552 bus->state = MDIOBUS_UNREGISTERED;
553
554 err = device_register(&bus->dev);
555 if (err) {
556 pr_err("mii_bus %s failed to register\n", bus->id);
557 return -EINVAL;
558 }
559
560 mutex_init(&bus->mdio_lock);
561 mutex_init(&bus->shared_lock);
562
563 /* assert bus level PHY GPIO reset */
564 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
565 if (IS_ERR(gpiod)) {
566 err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
567 "mii_bus %s couldn't get reset GPIO\n",
568 bus->id);
569 device_del(&bus->dev);
570 return err;
571 } else if (gpiod) {
572 bus->reset_gpiod = gpiod;
573 fsleep(bus->reset_delay_us);
574 gpiod_set_value_cansleep(gpiod, 0);
575 if (bus->reset_post_delay_us > 0)
576 fsleep(bus->reset_post_delay_us);
577 }
578
579 if (bus->reset) {
580 err = bus->reset(bus);
581 if (err)
582 goto error_reset_gpiod;
583 }
584
585 for (i = 0; i < PHY_MAX_ADDR; i++) {
586 if ((bus->phy_mask & (1 << i)) == 0) {
587 struct phy_device *phydev;
588
589 phydev = mdiobus_scan(bus, i);
590 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
591 err = PTR_ERR(phydev);
592 goto error;
593 }
594 }
595 }
596
597 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
598
599 bus->state = MDIOBUS_REGISTERED;
600 dev_dbg(&bus->dev, "probed\n");
601 return 0;
602
603 error:
604 while (--i >= 0) {
605 mdiodev = bus->mdio_map[i];
606 if (!mdiodev)
607 continue;
608
609 mdiodev->device_remove(mdiodev);
610 mdiodev->device_free(mdiodev);
611 }
612 error_reset_gpiod:
613 /* Put PHYs in RESET to save power */
614 if (bus->reset_gpiod)
615 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
616
617 device_del(&bus->dev);
618 return err;
619 }
620 EXPORT_SYMBOL(__mdiobus_register);
621
mdiobus_unregister(struct mii_bus * bus)622 void mdiobus_unregister(struct mii_bus *bus)
623 {
624 struct mdio_device *mdiodev;
625 int i;
626
627 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
628 return;
629 bus->state = MDIOBUS_UNREGISTERED;
630
631 for (i = 0; i < PHY_MAX_ADDR; i++) {
632 mdiodev = bus->mdio_map[i];
633 if (!mdiodev)
634 continue;
635
636 if (mdiodev->reset_gpio)
637 gpiod_put(mdiodev->reset_gpio);
638
639 mdiodev->device_remove(mdiodev);
640 mdiodev->device_free(mdiodev);
641 }
642
643 /* Put PHYs in RESET to save power */
644 if (bus->reset_gpiod)
645 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
646
647 device_del(&bus->dev);
648 }
649 EXPORT_SYMBOL(mdiobus_unregister);
650
651 /**
652 * mdiobus_free - free a struct mii_bus
653 * @bus: mii_bus to free
654 *
655 * This function releases the reference to the underlying device
656 * object in the mii_bus. If this is the last reference, the mii_bus
657 * will be freed.
658 */
mdiobus_free(struct mii_bus * bus)659 void mdiobus_free(struct mii_bus *bus)
660 {
661 /* For compatibility with error handling in drivers. */
662 if (bus->state == MDIOBUS_ALLOCATED) {
663 kfree(bus);
664 return;
665 }
666
667 WARN(bus->state != MDIOBUS_UNREGISTERED,
668 "%s: not in UNREGISTERED state\n", bus->id);
669 bus->state = MDIOBUS_RELEASED;
670
671 put_device(&bus->dev);
672 }
673 EXPORT_SYMBOL(mdiobus_free);
674
675 /**
676 * mdiobus_scan - scan a bus for MDIO devices.
677 * @bus: mii_bus to scan
678 * @addr: address on bus to scan
679 *
680 * This function scans the MDIO bus, looking for devices which can be
681 * identified using a vendor/product ID in registers 2 and 3. Not all
682 * MDIO devices have such registers, but PHY devices typically
683 * do. Hence this function assumes anything found is a PHY, or can be
684 * treated as a PHY. Other MDIO devices, such as switches, will
685 * probably not be found during the scan.
686 */
mdiobus_scan(struct mii_bus * bus,int addr)687 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
688 {
689 struct phy_device *phydev = ERR_PTR(-ENODEV);
690 int err;
691
692 switch (bus->probe_capabilities) {
693 case MDIOBUS_NO_CAP:
694 case MDIOBUS_C22:
695 phydev = get_phy_device(bus, addr, false);
696 break;
697 case MDIOBUS_C45:
698 phydev = get_phy_device(bus, addr, true);
699 break;
700 case MDIOBUS_C22_C45:
701 phydev = get_phy_device(bus, addr, false);
702 if (IS_ERR(phydev))
703 phydev = get_phy_device(bus, addr, true);
704 break;
705 }
706
707 if (IS_ERR(phydev))
708 return phydev;
709
710 /*
711 * For DT, see if the auto-probed phy has a correspoding child
712 * in the bus node, and set the of_node pointer in this case.
713 */
714 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
715
716 err = phy_device_register(phydev);
717 if (err) {
718 phy_device_free(phydev);
719 return ERR_PTR(-ENODEV);
720 }
721
722 return phydev;
723 }
724 EXPORT_SYMBOL(mdiobus_scan);
725
mdiobus_stats_acct(struct mdio_bus_stats * stats,bool op,int ret)726 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
727 {
728 preempt_disable();
729 u64_stats_update_begin(&stats->syncp);
730
731 u64_stats_inc(&stats->transfers);
732 if (ret < 0) {
733 u64_stats_inc(&stats->errors);
734 goto out;
735 }
736
737 if (op)
738 u64_stats_inc(&stats->reads);
739 else
740 u64_stats_inc(&stats->writes);
741 out:
742 u64_stats_update_end(&stats->syncp);
743 preempt_enable();
744 }
745
746 /**
747 * __mdiobus_read - Unlocked version of the mdiobus_read function
748 * @bus: the mii_bus struct
749 * @addr: the phy address
750 * @regnum: register number to read
751 *
752 * Read a MDIO bus register. Caller must hold the mdio bus lock.
753 *
754 * NOTE: MUST NOT be called from interrupt context.
755 */
__mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)756 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
757 {
758 int retval;
759
760 lockdep_assert_held_once(&bus->mdio_lock);
761
762 retval = bus->read(bus, addr, regnum);
763
764 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
765 mdiobus_stats_acct(&bus->stats[addr], true, retval);
766
767 return retval;
768 }
769 EXPORT_SYMBOL(__mdiobus_read);
770
771 /**
772 * __mdiobus_write - Unlocked version of the mdiobus_write function
773 * @bus: the mii_bus struct
774 * @addr: the phy address
775 * @regnum: register number to write
776 * @val: value to write to @regnum
777 *
778 * Write a MDIO bus register. Caller must hold the mdio bus lock.
779 *
780 * NOTE: MUST NOT be called from interrupt context.
781 */
__mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)782 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
783 {
784 int err;
785
786 lockdep_assert_held_once(&bus->mdio_lock);
787
788 err = bus->write(bus, addr, regnum, val);
789
790 trace_mdio_access(bus, 0, addr, regnum, val, err);
791 mdiobus_stats_acct(&bus->stats[addr], false, err);
792
793 return err;
794 }
795 EXPORT_SYMBOL(__mdiobus_write);
796
797 /**
798 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
799 * @bus: the mii_bus struct
800 * @addr: the phy address
801 * @regnum: register number to modify
802 * @mask: bit mask of bits to clear
803 * @set: bit mask of bits to set
804 *
805 * Read, modify, and if any change, write the register value back to the
806 * device. Any error returns a negative number.
807 *
808 * NOTE: MUST NOT be called from interrupt context.
809 */
__mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)810 int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
811 u16 mask, u16 set)
812 {
813 int new, ret;
814
815 ret = __mdiobus_read(bus, addr, regnum);
816 if (ret < 0)
817 return ret;
818
819 new = (ret & ~mask) | set;
820 if (new == ret)
821 return 0;
822
823 ret = __mdiobus_write(bus, addr, regnum, new);
824
825 return ret < 0 ? ret : 1;
826 }
827 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
828
829 /**
830 * mdiobus_read_nested - Nested version of the mdiobus_read function
831 * @bus: the mii_bus struct
832 * @addr: the phy address
833 * @regnum: register number to read
834 *
835 * In case of nested MDIO bus access avoid lockdep false positives by
836 * using mutex_lock_nested().
837 *
838 * NOTE: MUST NOT be called from interrupt context,
839 * because the bus read/write functions may wait for an interrupt
840 * to conclude the operation.
841 */
mdiobus_read_nested(struct mii_bus * bus,int addr,u32 regnum)842 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
843 {
844 int retval;
845
846 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
847 retval = __mdiobus_read(bus, addr, regnum);
848 mutex_unlock(&bus->mdio_lock);
849
850 return retval;
851 }
852 EXPORT_SYMBOL(mdiobus_read_nested);
853
854 /**
855 * mdiobus_read - Convenience function for reading a given MII mgmt register
856 * @bus: the mii_bus struct
857 * @addr: the phy address
858 * @regnum: register number to read
859 *
860 * NOTE: MUST NOT be called from interrupt context,
861 * because the bus read/write functions may wait for an interrupt
862 * to conclude the operation.
863 */
mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)864 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
865 {
866 int retval;
867
868 mutex_lock(&bus->mdio_lock);
869 retval = __mdiobus_read(bus, addr, regnum);
870 mutex_unlock(&bus->mdio_lock);
871
872 return retval;
873 }
874 EXPORT_SYMBOL(mdiobus_read);
875
876 /**
877 * mdiobus_write_nested - Nested version of the mdiobus_write function
878 * @bus: the mii_bus struct
879 * @addr: the phy address
880 * @regnum: register number to write
881 * @val: value to write to @regnum
882 *
883 * In case of nested MDIO bus access avoid lockdep false positives by
884 * using mutex_lock_nested().
885 *
886 * NOTE: MUST NOT be called from interrupt context,
887 * because the bus read/write functions may wait for an interrupt
888 * to conclude the operation.
889 */
mdiobus_write_nested(struct mii_bus * bus,int addr,u32 regnum,u16 val)890 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
891 {
892 int err;
893
894 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
895 err = __mdiobus_write(bus, addr, regnum, val);
896 mutex_unlock(&bus->mdio_lock);
897
898 return err;
899 }
900 EXPORT_SYMBOL(mdiobus_write_nested);
901
902 /**
903 * mdiobus_write - Convenience function for writing a given MII mgmt register
904 * @bus: the mii_bus struct
905 * @addr: the phy address
906 * @regnum: register number to write
907 * @val: value to write to @regnum
908 *
909 * NOTE: MUST NOT be called from interrupt context,
910 * because the bus read/write functions may wait for an interrupt
911 * to conclude the operation.
912 */
mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)913 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
914 {
915 int err;
916
917 mutex_lock(&bus->mdio_lock);
918 err = __mdiobus_write(bus, addr, regnum, val);
919 mutex_unlock(&bus->mdio_lock);
920
921 return err;
922 }
923 EXPORT_SYMBOL(mdiobus_write);
924
925 /**
926 * mdiobus_modify - Convenience function for modifying a given mdio device
927 * register
928 * @bus: the mii_bus struct
929 * @addr: the phy address
930 * @regnum: register number to write
931 * @mask: bit mask of bits to clear
932 * @set: bit mask of bits to set
933 */
mdiobus_modify(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)934 int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
935 {
936 int err;
937
938 mutex_lock(&bus->mdio_lock);
939 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
940 mutex_unlock(&bus->mdio_lock);
941
942 return err < 0 ? err : 0;
943 }
944 EXPORT_SYMBOL_GPL(mdiobus_modify);
945
946 /**
947 * mdiobus_modify_changed - Convenience function for modifying a given mdio
948 * device register and returning if it changed
949 * @bus: the mii_bus struct
950 * @addr: the phy address
951 * @regnum: register number to write
952 * @mask: bit mask of bits to clear
953 * @set: bit mask of bits to set
954 */
mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)955 int mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
956 u16 mask, u16 set)
957 {
958 int err;
959
960 mutex_lock(&bus->mdio_lock);
961 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
962 mutex_unlock(&bus->mdio_lock);
963
964 return err;
965 }
966 EXPORT_SYMBOL_GPL(mdiobus_modify_changed);
967
968 /**
969 * mdio_bus_match - determine if given MDIO driver supports the given
970 * MDIO device
971 * @dev: target MDIO device
972 * @drv: given MDIO driver
973 *
974 * Description: Given a MDIO device, and a MDIO driver, return 1 if
975 * the driver supports the device. Otherwise, return 0. This may
976 * require calling the devices own match function, since different classes
977 * of MDIO devices have different match criteria.
978 */
mdio_bus_match(struct device * dev,struct device_driver * drv)979 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
980 {
981 struct mdio_driver *mdiodrv = to_mdio_driver(drv);
982 struct mdio_device *mdio = to_mdio_device(dev);
983
984 /* Both the driver and device must type-match */
985 if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=
986 !(mdio->flags & MDIO_DEVICE_FLAG_PHY))
987 return 0;
988
989 if (of_driver_match_device(dev, drv))
990 return 1;
991
992 if (mdio->bus_match)
993 return mdio->bus_match(dev, drv);
994
995 return 0;
996 }
997
mdio_uevent(struct device * dev,struct kobj_uevent_env * env)998 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
999 {
1000 int rc;
1001
1002 /* Some devices have extra OF data and an OF-style MODALIAS */
1003 rc = of_device_uevent_modalias(dev, env);
1004 if (rc != -ENODEV)
1005 return rc;
1006
1007 return 0;
1008 }
1009
1010 static struct attribute *mdio_bus_device_statistics_attrs[] = {
1011 &dev_attr_mdio_bus_device_transfers.attr.attr,
1012 &dev_attr_mdio_bus_device_errors.attr.attr,
1013 &dev_attr_mdio_bus_device_writes.attr.attr,
1014 &dev_attr_mdio_bus_device_reads.attr.attr,
1015 NULL,
1016 };
1017
1018 static const struct attribute_group mdio_bus_device_statistics_group = {
1019 .name = "statistics",
1020 .attrs = mdio_bus_device_statistics_attrs,
1021 };
1022
1023 static const struct attribute_group *mdio_bus_dev_groups[] = {
1024 &mdio_bus_device_statistics_group,
1025 NULL,
1026 };
1027
1028 struct bus_type mdio_bus_type = {
1029 .name = "mdio_bus",
1030 .dev_groups = mdio_bus_dev_groups,
1031 .match = mdio_bus_match,
1032 .uevent = mdio_uevent,
1033 };
1034 EXPORT_SYMBOL(mdio_bus_type);
1035
mdio_bus_init(void)1036 int __init mdio_bus_init(void)
1037 {
1038 int ret;
1039
1040 ret = class_register(&mdio_bus_class);
1041 if (!ret) {
1042 ret = bus_register(&mdio_bus_type);
1043 if (ret)
1044 class_unregister(&mdio_bus_class);
1045 }
1046
1047 return ret;
1048 }
1049
1050 #if IS_ENABLED(CONFIG_PHYLIB)
mdio_bus_exit(void)1051 void mdio_bus_exit(void)
1052 {
1053 class_unregister(&mdio_bus_class);
1054 bus_unregister(&mdio_bus_type);
1055 }
1056 EXPORT_SYMBOL_GPL(mdio_bus_exit);
1057 #else
1058 module_init(mdio_bus_init);
1059 /* no module_exit, intentional */
1060 MODULE_LICENSE("GPL");
1061 MODULE_DESCRIPTION("MDIO bus/device layer");
1062 #endif
1063