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