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;
112
113 if (addr < 0 || addr >= ARRAY_SIZE(bus->mdio_map))
114 return NULL;
115
116 mdiodev = bus->mdio_map[addr];
117
118 if (!mdiodev)
119 return NULL;
120
121 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
122 return NULL;
123
124 return container_of(mdiodev, struct phy_device, mdio);
125 }
126 EXPORT_SYMBOL(mdiobus_get_phy);
127
mdiobus_is_registered_device(struct mii_bus * bus,int addr)128 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
129 {
130 return bus->mdio_map[addr];
131 }
132 EXPORT_SYMBOL(mdiobus_is_registered_device);
133
134 /**
135 * mdiobus_alloc_size - allocate a mii_bus structure
136 * @size: extra amount of memory to allocate for private storage.
137 * If non-zero, then bus->priv is points to that memory.
138 *
139 * Description: called by a bus driver to allocate an mii_bus
140 * structure to fill in.
141 */
mdiobus_alloc_size(size_t size)142 struct mii_bus *mdiobus_alloc_size(size_t size)
143 {
144 struct mii_bus *bus;
145 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
146 size_t alloc_size;
147 int i;
148
149 /* If we alloc extra space, it should be aligned */
150 if (size)
151 alloc_size = aligned_size + size;
152 else
153 alloc_size = sizeof(*bus);
154
155 bus = kzalloc(alloc_size, GFP_KERNEL);
156 if (!bus)
157 return NULL;
158
159 bus->state = MDIOBUS_ALLOCATED;
160 if (size)
161 bus->priv = (void *)bus + aligned_size;
162
163 /* Initialise the interrupts to polling and 64-bit seqcounts */
164 for (i = 0; i < PHY_MAX_ADDR; i++) {
165 bus->irq[i] = PHY_POLL;
166 u64_stats_init(&bus->stats[i].syncp);
167 }
168
169 return bus;
170 }
171 EXPORT_SYMBOL(mdiobus_alloc_size);
172
173 /**
174 * mdiobus_release - mii_bus device release callback
175 * @d: the target struct device that contains the mii_bus
176 *
177 * Description: called when the last reference to an mii_bus is
178 * dropped, to free the underlying memory.
179 */
mdiobus_release(struct device * d)180 static void mdiobus_release(struct device *d)
181 {
182 struct mii_bus *bus = to_mii_bus(d);
183
184 WARN(bus->state != MDIOBUS_RELEASED &&
185 /* for compatibility with error handling in drivers */
186 bus->state != MDIOBUS_ALLOCATED,
187 "%s: not in RELEASED or ALLOCATED state\n",
188 bus->id);
189 kfree(bus);
190 }
191
192 struct mdio_bus_stat_attr {
193 int addr;
194 unsigned int field_offset;
195 };
196
mdio_bus_get_stat(struct mdio_bus_stats * s,unsigned int offset)197 static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
198 {
199 const char *p = (const char *)s + offset;
200 unsigned int start;
201 u64 val = 0;
202
203 do {
204 start = u64_stats_fetch_begin(&s->syncp);
205 val = u64_stats_read((const u64_stats_t *)p);
206 } while (u64_stats_fetch_retry(&s->syncp, start));
207
208 return val;
209 }
210
mdio_bus_get_global_stat(struct mii_bus * bus,unsigned int offset)211 static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
212 {
213 unsigned int i;
214 u64 val = 0;
215
216 for (i = 0; i < PHY_MAX_ADDR; i++)
217 val += mdio_bus_get_stat(&bus->stats[i], offset);
218
219 return val;
220 }
221
mdio_bus_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)222 static ssize_t mdio_bus_stat_field_show(struct device *dev,
223 struct device_attribute *attr,
224 char *buf)
225 {
226 struct mii_bus *bus = to_mii_bus(dev);
227 struct mdio_bus_stat_attr *sattr;
228 struct dev_ext_attribute *eattr;
229 u64 val;
230
231 eattr = container_of(attr, struct dev_ext_attribute, attr);
232 sattr = eattr->var;
233
234 if (sattr->addr < 0)
235 val = mdio_bus_get_global_stat(bus, sattr->field_offset);
236 else
237 val = mdio_bus_get_stat(&bus->stats[sattr->addr],
238 sattr->field_offset);
239
240 return sysfs_emit(buf, "%llu\n", val);
241 }
242
mdio_bus_device_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)243 static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
244 struct device_attribute *attr,
245 char *buf)
246 {
247 struct mdio_device *mdiodev = to_mdio_device(dev);
248 struct mii_bus *bus = mdiodev->bus;
249 struct mdio_bus_stat_attr *sattr;
250 struct dev_ext_attribute *eattr;
251 int addr = mdiodev->addr;
252 u64 val;
253
254 eattr = container_of(attr, struct dev_ext_attribute, attr);
255 sattr = eattr->var;
256
257 val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);
258
259 return sysfs_emit(buf, "%llu\n", val);
260 }
261
262 #define MDIO_BUS_STATS_ATTR_DECL(field, file) \
263 static struct dev_ext_attribute dev_attr_mdio_bus_##field = { \
264 .attr = { .attr = { .name = file, .mode = 0444 }, \
265 .show = mdio_bus_stat_field_show, \
266 }, \
267 .var = &((struct mdio_bus_stat_attr) { \
268 -1, offsetof(struct mdio_bus_stats, field) \
269 }), \
270 }; \
271 static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = { \
272 .attr = { .attr = { .name = file, .mode = 0444 }, \
273 .show = mdio_bus_device_stat_field_show, \
274 }, \
275 .var = &((struct mdio_bus_stat_attr) { \
276 -1, offsetof(struct mdio_bus_stats, field) \
277 }), \
278 };
279
280 #define MDIO_BUS_STATS_ATTR(field) \
281 MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
282
283 MDIO_BUS_STATS_ATTR(transfers);
284 MDIO_BUS_STATS_ATTR(errors);
285 MDIO_BUS_STATS_ATTR(writes);
286 MDIO_BUS_STATS_ATTR(reads);
287
288 #define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file) \
289 static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \
290 .attr = { .attr = { .name = file, .mode = 0444 }, \
291 .show = mdio_bus_stat_field_show, \
292 }, \
293 .var = &((struct mdio_bus_stat_attr) { \
294 addr, offsetof(struct mdio_bus_stats, field) \
295 }), \
296 }
297
298 #define MDIO_BUS_STATS_ADDR_ATTR(field, addr) \
299 MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, \
300 __stringify(field) "_" __stringify(addr))
301
302 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr) \
303 MDIO_BUS_STATS_ADDR_ATTR(transfers, addr); \
304 MDIO_BUS_STATS_ADDR_ATTR(errors, addr); \
305 MDIO_BUS_STATS_ADDR_ATTR(writes, addr); \
306 MDIO_BUS_STATS_ADDR_ATTR(reads, addr) \
307
308 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
309 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
310 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
311 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
312 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
313 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
314 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
315 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
316 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
317 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
318 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
319 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
320 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
321 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
322 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
323 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
324 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
325 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
326 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
327 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
328 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
329 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
330 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
331 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
332 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
333 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
334 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
335 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
336 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
337 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
338 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
339 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
340
341 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr) \
342 &dev_attr_mdio_bus_addr_transfers_##addr.attr.attr, \
343 &dev_attr_mdio_bus_addr_errors_##addr.attr.attr, \
344 &dev_attr_mdio_bus_addr_writes_##addr.attr.attr, \
345 &dev_attr_mdio_bus_addr_reads_##addr.attr.attr \
346
347 static struct attribute *mdio_bus_statistics_attrs[] = {
348 &dev_attr_mdio_bus_transfers.attr.attr,
349 &dev_attr_mdio_bus_errors.attr.attr,
350 &dev_attr_mdio_bus_writes.attr.attr,
351 &dev_attr_mdio_bus_reads.attr.attr,
352 MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),
353 MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),
354 MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),
355 MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),
356 MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),
357 MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),
358 MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),
359 MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),
360 MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),
361 MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),
362 MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),
363 MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),
364 MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),
365 MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),
366 MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),
367 MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),
368 MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),
369 MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),
370 MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),
371 MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),
372 MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),
373 MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),
374 MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),
375 MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),
376 MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),
377 MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),
378 MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),
379 MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),
380 MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),
381 MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),
382 MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),
383 MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),
384 NULL,
385 };
386
387 static const struct attribute_group mdio_bus_statistics_group = {
388 .name = "statistics",
389 .attrs = mdio_bus_statistics_attrs,
390 };
391
392 static const struct attribute_group *mdio_bus_groups[] = {
393 &mdio_bus_statistics_group,
394 NULL,
395 };
396
397 static struct class mdio_bus_class = {
398 .name = "mdio_bus",
399 .dev_release = mdiobus_release,
400 .dev_groups = mdio_bus_groups,
401 };
402
403 /**
404 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
405 * @mdio_name: The name of a mdiobus.
406 *
407 * Returns a reference to the mii_bus, or NULL if none found. The
408 * embedded struct device will have its reference count incremented,
409 * and this must be put_deviced'ed once the bus is finished with.
410 */
mdio_find_bus(const char * mdio_name)411 struct mii_bus *mdio_find_bus(const char *mdio_name)
412 {
413 struct device *d;
414
415 d = class_find_device_by_name(&mdio_bus_class, mdio_name);
416 return d ? to_mii_bus(d) : NULL;
417 }
418 EXPORT_SYMBOL(mdio_find_bus);
419
420 #if IS_ENABLED(CONFIG_OF_MDIO)
421 /**
422 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
423 * @mdio_bus_np: Pointer to the mii_bus.
424 *
425 * Returns a reference to the mii_bus, or NULL if none found. The
426 * embedded struct device will have its reference count incremented,
427 * and this must be put once the bus is finished with.
428 *
429 * Because the association of a device_node and mii_bus is made via
430 * of_mdiobus_register(), the mii_bus cannot be found before it is
431 * registered with of_mdiobus_register().
432 *
433 */
of_mdio_find_bus(struct device_node * mdio_bus_np)434 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
435 {
436 struct device *d;
437
438 if (!mdio_bus_np)
439 return NULL;
440
441 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
442 return d ? to_mii_bus(d) : NULL;
443 }
444 EXPORT_SYMBOL(of_mdio_find_bus);
445
446 /* Walk the list of subnodes of a mdio bus and look for a node that
447 * matches the mdio device's address with its 'reg' property. If
448 * found, set the of_node pointer for the mdio device. This allows
449 * auto-probed phy devices to be supplied with information passed in
450 * via DT.
451 */
of_mdiobus_link_mdiodev(struct mii_bus * bus,struct mdio_device * mdiodev)452 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
453 struct mdio_device *mdiodev)
454 {
455 struct device *dev = &mdiodev->dev;
456 struct device_node *child;
457
458 if (dev->of_node || !bus->dev.of_node)
459 return;
460
461 for_each_available_child_of_node(bus->dev.of_node, child) {
462 int addr;
463
464 addr = of_mdio_parse_addr(dev, child);
465 if (addr < 0)
466 continue;
467
468 if (addr == mdiodev->addr) {
469 device_set_node(dev, of_fwnode_handle(child));
470 /* The refcount on "child" is passed to the mdio
471 * device. Do _not_ use of_node_put(child) here.
472 */
473 return;
474 }
475 }
476 }
477 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
of_mdiobus_link_mdiodev(struct mii_bus * mdio,struct mdio_device * mdiodev)478 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
479 struct mdio_device *mdiodev)
480 {
481 }
482 #endif
483
484 /**
485 * mdiobus_create_device - create a full MDIO device given
486 * a mdio_board_info structure
487 * @bus: MDIO bus to create the devices on
488 * @bi: mdio_board_info structure describing the devices
489 *
490 * Returns 0 on success or < 0 on error.
491 */
mdiobus_create_device(struct mii_bus * bus,struct mdio_board_info * bi)492 static int mdiobus_create_device(struct mii_bus *bus,
493 struct mdio_board_info *bi)
494 {
495 struct mdio_device *mdiodev;
496 int ret = 0;
497
498 mdiodev = mdio_device_create(bus, bi->mdio_addr);
499 if (IS_ERR(mdiodev))
500 return -ENODEV;
501
502 strncpy(mdiodev->modalias, bi->modalias,
503 sizeof(mdiodev->modalias));
504 mdiodev->bus_match = mdio_device_bus_match;
505 mdiodev->dev.platform_data = (void *)bi->platform_data;
506
507 ret = mdio_device_register(mdiodev);
508 if (ret)
509 mdio_device_free(mdiodev);
510
511 return ret;
512 }
513
514 /**
515 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
516 * @bus: target mii_bus
517 * @owner: module containing bus accessor functions
518 *
519 * Description: Called by a bus driver to bring up all the PHYs
520 * on a given bus, and attach them to the bus. Drivers should use
521 * mdiobus_register() rather than __mdiobus_register() unless they
522 * need to pass a specific owner module. MDIO devices which are not
523 * PHYs will not be brought up by this function. They are expected
524 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
525 *
526 * Returns 0 on success or < 0 on error.
527 */
__mdiobus_register(struct mii_bus * bus,struct module * owner)528 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
529 {
530 struct mdio_device *mdiodev;
531 int i, err;
532 struct gpio_desc *gpiod;
533
534 if (NULL == bus || NULL == bus->name ||
535 NULL == bus->read || NULL == bus->write)
536 return -EINVAL;
537
538 if (bus->parent && bus->parent->of_node)
539 bus->parent->of_node->fwnode.flags |=
540 FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
541
542 WARN(bus->state != MDIOBUS_ALLOCATED &&
543 bus->state != MDIOBUS_UNREGISTERED,
544 "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
545
546 bus->owner = owner;
547 bus->dev.parent = bus->parent;
548 bus->dev.class = &mdio_bus_class;
549 bus->dev.groups = NULL;
550 dev_set_name(&bus->dev, "%s", bus->id);
551
552 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
553 * the device in mdiobus_free()
554 *
555 * State will be updated later in this function in case of success
556 */
557 bus->state = MDIOBUS_UNREGISTERED;
558
559 err = device_register(&bus->dev);
560 if (err) {
561 pr_err("mii_bus %s failed to register\n", bus->id);
562 return -EINVAL;
563 }
564
565 mutex_init(&bus->mdio_lock);
566 mutex_init(&bus->shared_lock);
567
568 /* assert bus level PHY GPIO reset */
569 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
570 if (IS_ERR(gpiod)) {
571 err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
572 "mii_bus %s couldn't get reset GPIO\n",
573 bus->id);
574 device_del(&bus->dev);
575 return err;
576 } else if (gpiod) {
577 bus->reset_gpiod = gpiod;
578 fsleep(bus->reset_delay_us);
579 gpiod_set_value_cansleep(gpiod, 0);
580 if (bus->reset_post_delay_us > 0)
581 fsleep(bus->reset_post_delay_us);
582 }
583
584 if (bus->reset) {
585 err = bus->reset(bus);
586 if (err)
587 goto error_reset_gpiod;
588 }
589
590 for (i = 0; i < PHY_MAX_ADDR; i++) {
591 if ((bus->phy_mask & BIT(i)) == 0) {
592 struct phy_device *phydev;
593
594 phydev = mdiobus_scan(bus, i);
595 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
596 err = PTR_ERR(phydev);
597 goto error;
598 }
599 }
600 }
601
602 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
603
604 bus->state = MDIOBUS_REGISTERED;
605 dev_dbg(&bus->dev, "probed\n");
606 return 0;
607
608 error:
609 while (--i >= 0) {
610 mdiodev = bus->mdio_map[i];
611 if (!mdiodev)
612 continue;
613
614 mdiodev->device_remove(mdiodev);
615 mdiodev->device_free(mdiodev);
616 }
617 error_reset_gpiod:
618 /* Put PHYs in RESET to save power */
619 if (bus->reset_gpiod)
620 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
621
622 device_del(&bus->dev);
623 return err;
624 }
625 EXPORT_SYMBOL(__mdiobus_register);
626
mdiobus_unregister(struct mii_bus * bus)627 void mdiobus_unregister(struct mii_bus *bus)
628 {
629 struct mdio_device *mdiodev;
630 int i;
631
632 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
633 return;
634 bus->state = MDIOBUS_UNREGISTERED;
635
636 for (i = 0; i < PHY_MAX_ADDR; i++) {
637 mdiodev = bus->mdio_map[i];
638 if (!mdiodev)
639 continue;
640
641 if (mdiodev->reset_gpio)
642 gpiod_put(mdiodev->reset_gpio);
643
644 mdiodev->device_remove(mdiodev);
645 mdiodev->device_free(mdiodev);
646 }
647
648 /* Put PHYs in RESET to save power */
649 if (bus->reset_gpiod)
650 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
651
652 device_del(&bus->dev);
653 }
654 EXPORT_SYMBOL(mdiobus_unregister);
655
656 /**
657 * mdiobus_free - free a struct mii_bus
658 * @bus: mii_bus to free
659 *
660 * This function releases the reference to the underlying device
661 * object in the mii_bus. If this is the last reference, the mii_bus
662 * will be freed.
663 */
mdiobus_free(struct mii_bus * bus)664 void mdiobus_free(struct mii_bus *bus)
665 {
666 /* For compatibility with error handling in drivers. */
667 if (bus->state == MDIOBUS_ALLOCATED) {
668 kfree(bus);
669 return;
670 }
671
672 WARN(bus->state != MDIOBUS_UNREGISTERED,
673 "%s: not in UNREGISTERED state\n", bus->id);
674 bus->state = MDIOBUS_RELEASED;
675
676 put_device(&bus->dev);
677 }
678 EXPORT_SYMBOL(mdiobus_free);
679
680 /**
681 * mdiobus_scan - scan a bus for MDIO devices.
682 * @bus: mii_bus to scan
683 * @addr: address on bus to scan
684 *
685 * This function scans the MDIO bus, looking for devices which can be
686 * identified using a vendor/product ID in registers 2 and 3. Not all
687 * MDIO devices have such registers, but PHY devices typically
688 * do. Hence this function assumes anything found is a PHY, or can be
689 * treated as a PHY. Other MDIO devices, such as switches, will
690 * probably not be found during the scan.
691 */
mdiobus_scan(struct mii_bus * bus,int addr)692 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
693 {
694 struct phy_device *phydev = ERR_PTR(-ENODEV);
695 int err;
696
697 switch (bus->probe_capabilities) {
698 case MDIOBUS_NO_CAP:
699 case MDIOBUS_C22:
700 phydev = get_phy_device(bus, addr, false);
701 break;
702 case MDIOBUS_C45:
703 phydev = get_phy_device(bus, addr, true);
704 break;
705 case MDIOBUS_C22_C45:
706 phydev = get_phy_device(bus, addr, false);
707 if (IS_ERR(phydev))
708 phydev = get_phy_device(bus, addr, true);
709 break;
710 }
711
712 if (IS_ERR(phydev))
713 return phydev;
714
715 /*
716 * For DT, see if the auto-probed phy has a correspoding child
717 * in the bus node, and set the of_node pointer in this case.
718 */
719 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
720
721 err = phy_device_register(phydev);
722 if (err) {
723 phy_device_free(phydev);
724 return ERR_PTR(-ENODEV);
725 }
726
727 return phydev;
728 }
729 EXPORT_SYMBOL(mdiobus_scan);
730
mdiobus_stats_acct(struct mdio_bus_stats * stats,bool op,int ret)731 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
732 {
733 preempt_disable();
734 u64_stats_update_begin(&stats->syncp);
735
736 u64_stats_inc(&stats->transfers);
737 if (ret < 0) {
738 u64_stats_inc(&stats->errors);
739 goto out;
740 }
741
742 if (op)
743 u64_stats_inc(&stats->reads);
744 else
745 u64_stats_inc(&stats->writes);
746 out:
747 u64_stats_update_end(&stats->syncp);
748 preempt_enable();
749 }
750
751 /**
752 * __mdiobus_read - Unlocked version of the mdiobus_read function
753 * @bus: the mii_bus struct
754 * @addr: the phy address
755 * @regnum: register number to read
756 *
757 * Read a MDIO bus register. Caller must hold the mdio bus lock.
758 *
759 * NOTE: MUST NOT be called from interrupt context.
760 */
__mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)761 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
762 {
763 int retval;
764
765 lockdep_assert_held_once(&bus->mdio_lock);
766
767 retval = bus->read(bus, addr, regnum);
768
769 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
770 mdiobus_stats_acct(&bus->stats[addr], true, retval);
771
772 return retval;
773 }
774 EXPORT_SYMBOL(__mdiobus_read);
775
776 /**
777 * __mdiobus_write - Unlocked version of the mdiobus_write function
778 * @bus: the mii_bus struct
779 * @addr: the phy address
780 * @regnum: register number to write
781 * @val: value to write to @regnum
782 *
783 * Write a MDIO bus register. Caller must hold the mdio bus lock.
784 *
785 * NOTE: MUST NOT be called from interrupt context.
786 */
__mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)787 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
788 {
789 int err;
790
791 lockdep_assert_held_once(&bus->mdio_lock);
792
793 err = bus->write(bus, addr, regnum, val);
794
795 trace_mdio_access(bus, 0, addr, regnum, val, err);
796 mdiobus_stats_acct(&bus->stats[addr], false, err);
797
798 return err;
799 }
800 EXPORT_SYMBOL(__mdiobus_write);
801
802 /**
803 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
804 * @bus: the mii_bus struct
805 * @addr: the phy address
806 * @regnum: register number to modify
807 * @mask: bit mask of bits to clear
808 * @set: bit mask of bits to set
809 *
810 * Read, modify, and if any change, write the register value back to the
811 * device. Any error returns a negative number.
812 *
813 * NOTE: MUST NOT be called from interrupt context.
814 */
__mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)815 int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
816 u16 mask, u16 set)
817 {
818 int new, ret;
819
820 ret = __mdiobus_read(bus, addr, regnum);
821 if (ret < 0)
822 return ret;
823
824 new = (ret & ~mask) | set;
825 if (new == ret)
826 return 0;
827
828 ret = __mdiobus_write(bus, addr, regnum, new);
829
830 return ret < 0 ? ret : 1;
831 }
832 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
833
834 /**
835 * mdiobus_read_nested - Nested version of the mdiobus_read function
836 * @bus: the mii_bus struct
837 * @addr: the phy address
838 * @regnum: register number to read
839 *
840 * In case of nested MDIO bus access avoid lockdep false positives by
841 * using mutex_lock_nested().
842 *
843 * NOTE: MUST NOT be called from interrupt context,
844 * because the bus read/write functions may wait for an interrupt
845 * to conclude the operation.
846 */
mdiobus_read_nested(struct mii_bus * bus,int addr,u32 regnum)847 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
848 {
849 int retval;
850
851 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
852 retval = __mdiobus_read(bus, addr, regnum);
853 mutex_unlock(&bus->mdio_lock);
854
855 return retval;
856 }
857 EXPORT_SYMBOL(mdiobus_read_nested);
858
859 /**
860 * mdiobus_read - Convenience function for reading a given MII mgmt register
861 * @bus: the mii_bus struct
862 * @addr: the phy address
863 * @regnum: register number to read
864 *
865 * NOTE: MUST NOT be called from interrupt context,
866 * because the bus read/write functions may wait for an interrupt
867 * to conclude the operation.
868 */
mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)869 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
870 {
871 int retval;
872
873 mutex_lock(&bus->mdio_lock);
874 retval = __mdiobus_read(bus, addr, regnum);
875 mutex_unlock(&bus->mdio_lock);
876
877 return retval;
878 }
879 EXPORT_SYMBOL(mdiobus_read);
880
881 /**
882 * mdiobus_write_nested - Nested version of the mdiobus_write function
883 * @bus: the mii_bus struct
884 * @addr: the phy address
885 * @regnum: register number to write
886 * @val: value to write to @regnum
887 *
888 * In case of nested MDIO bus access avoid lockdep false positives by
889 * using mutex_lock_nested().
890 *
891 * NOTE: MUST NOT be called from interrupt context,
892 * because the bus read/write functions may wait for an interrupt
893 * to conclude the operation.
894 */
mdiobus_write_nested(struct mii_bus * bus,int addr,u32 regnum,u16 val)895 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
896 {
897 int err;
898
899 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
900 err = __mdiobus_write(bus, addr, regnum, val);
901 mutex_unlock(&bus->mdio_lock);
902
903 return err;
904 }
905 EXPORT_SYMBOL(mdiobus_write_nested);
906
907 /**
908 * mdiobus_write - Convenience function for writing a given MII mgmt register
909 * @bus: the mii_bus struct
910 * @addr: the phy address
911 * @regnum: register number to write
912 * @val: value to write to @regnum
913 *
914 * NOTE: MUST NOT be called from interrupt context,
915 * because the bus read/write functions may wait for an interrupt
916 * to conclude the operation.
917 */
mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)918 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
919 {
920 int err;
921
922 mutex_lock(&bus->mdio_lock);
923 err = __mdiobus_write(bus, addr, regnum, val);
924 mutex_unlock(&bus->mdio_lock);
925
926 return err;
927 }
928 EXPORT_SYMBOL(mdiobus_write);
929
930 /**
931 * mdiobus_modify - Convenience function for modifying a given mdio device
932 * register
933 * @bus: the mii_bus struct
934 * @addr: the phy address
935 * @regnum: register number to write
936 * @mask: bit mask of bits to clear
937 * @set: bit mask of bits to set
938 */
mdiobus_modify(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)939 int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
940 {
941 int err;
942
943 mutex_lock(&bus->mdio_lock);
944 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
945 mutex_unlock(&bus->mdio_lock);
946
947 return err < 0 ? err : 0;
948 }
949 EXPORT_SYMBOL_GPL(mdiobus_modify);
950
951 /**
952 * mdiobus_modify_changed - Convenience function for modifying a given mdio
953 * device register and returning if it changed
954 * @bus: the mii_bus struct
955 * @addr: the phy address
956 * @regnum: register number to write
957 * @mask: bit mask of bits to clear
958 * @set: bit mask of bits to set
959 */
mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)960 int mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
961 u16 mask, u16 set)
962 {
963 int err;
964
965 mutex_lock(&bus->mdio_lock);
966 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
967 mutex_unlock(&bus->mdio_lock);
968
969 return err;
970 }
971 EXPORT_SYMBOL_GPL(mdiobus_modify_changed);
972
973 /**
974 * mdio_bus_match - determine if given MDIO driver supports the given
975 * MDIO device
976 * @dev: target MDIO device
977 * @drv: given MDIO driver
978 *
979 * Description: Given a MDIO device, and a MDIO driver, return 1 if
980 * the driver supports the device. Otherwise, return 0. This may
981 * require calling the devices own match function, since different classes
982 * of MDIO devices have different match criteria.
983 */
mdio_bus_match(struct device * dev,struct device_driver * drv)984 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
985 {
986 struct mdio_driver *mdiodrv = to_mdio_driver(drv);
987 struct mdio_device *mdio = to_mdio_device(dev);
988
989 /* Both the driver and device must type-match */
990 if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=
991 !(mdio->flags & MDIO_DEVICE_FLAG_PHY))
992 return 0;
993
994 if (of_driver_match_device(dev, drv))
995 return 1;
996
997 if (mdio->bus_match)
998 return mdio->bus_match(dev, drv);
999
1000 return 0;
1001 }
1002
mdio_uevent(struct device * dev,struct kobj_uevent_env * env)1003 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
1004 {
1005 int rc;
1006
1007 /* Some devices have extra OF data and an OF-style MODALIAS */
1008 rc = of_device_uevent_modalias(dev, env);
1009 if (rc != -ENODEV)
1010 return rc;
1011
1012 return 0;
1013 }
1014
1015 static struct attribute *mdio_bus_device_statistics_attrs[] = {
1016 &dev_attr_mdio_bus_device_transfers.attr.attr,
1017 &dev_attr_mdio_bus_device_errors.attr.attr,
1018 &dev_attr_mdio_bus_device_writes.attr.attr,
1019 &dev_attr_mdio_bus_device_reads.attr.attr,
1020 NULL,
1021 };
1022
1023 static const struct attribute_group mdio_bus_device_statistics_group = {
1024 .name = "statistics",
1025 .attrs = mdio_bus_device_statistics_attrs,
1026 };
1027
1028 static const struct attribute_group *mdio_bus_dev_groups[] = {
1029 &mdio_bus_device_statistics_group,
1030 NULL,
1031 };
1032
1033 struct bus_type mdio_bus_type = {
1034 .name = "mdio_bus",
1035 .dev_groups = mdio_bus_dev_groups,
1036 .match = mdio_bus_match,
1037 .uevent = mdio_uevent,
1038 };
1039 EXPORT_SYMBOL(mdio_bus_type);
1040
mdio_bus_init(void)1041 int __init mdio_bus_init(void)
1042 {
1043 int ret;
1044
1045 ret = class_register(&mdio_bus_class);
1046 if (!ret) {
1047 ret = bus_register(&mdio_bus_type);
1048 if (ret)
1049 class_unregister(&mdio_bus_class);
1050 }
1051
1052 return ret;
1053 }
1054
1055 #if IS_ENABLED(CONFIG_PHYLIB)
mdio_bus_exit(void)1056 void mdio_bus_exit(void)
1057 {
1058 class_unregister(&mdio_bus_class);
1059 bus_unregister(&mdio_bus_type);
1060 }
1061 EXPORT_SYMBOL_GPL(mdio_bus_exit);
1062 #else
1063 module_init(mdio_bus_init);
1064 /* no module_exit, intentional */
1065 MODULE_LICENSE("GPL");
1066 MODULE_DESCRIPTION("MDIO bus/device layer");
1067 #endif
1068