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