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