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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/* 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/of_device.h>
26#include <linux/of_mdio.h>
27#include <linux/netdevice.h>
28#include <linux/etherdevice.h>
29#include <linux/skbuff.h>
30#include <linux/spinlock.h>
31#include <linux/mm.h>
32#include <linux/module.h>
33#include <linux/mii.h>
34#include <linux/ethtool.h>
35#include <linux/phy.h>
36#include <linux/io.h>
37#include <linux/uaccess.h>
38
39#include <asm/irq.h>
40
41/**
42 * mdiobus_alloc_size - allocate a mii_bus structure
43 * @size: extra amount of memory to allocate for private storage.
44 * If non-zero, then bus->priv is points to that memory.
45 *
46 * Description: called by a bus driver to allocate an mii_bus
47 * structure to fill in.
48 */
49struct mii_bus *mdiobus_alloc_size(size_t size)
50{
51 struct mii_bus *bus;
52 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
53 size_t alloc_size;
54
55 /* If we alloc extra space, it should be aligned */
56 if (size)
57 alloc_size = aligned_size + size;
58 else
59 alloc_size = sizeof(*bus);
60
61 bus = kzalloc(alloc_size, GFP_KERNEL);
62 if (bus) {
63 bus->state = MDIOBUS_ALLOCATED;
64 if (size)
65 bus->priv = (void *)bus + aligned_size;
66 }
67
68 return bus;
69}
70EXPORT_SYMBOL(mdiobus_alloc_size);
71
72/**
73 * mdiobus_release - mii_bus device release callback
74 * @d: the target struct device that contains the mii_bus
75 *
76 * Description: called when the last reference to an mii_bus is
77 * dropped, to free the underlying memory.
78 */
79static void mdiobus_release(struct device *d)
80{
81 struct mii_bus *bus = to_mii_bus(d);
82 BUG_ON(bus->state != MDIOBUS_RELEASED &&
83 /* for compatibility with error handling in drivers */
84 bus->state != MDIOBUS_ALLOCATED);
85 kfree(bus);
86}
87
88static struct class mdio_bus_class = {
89 .name = "mdio_bus",
90 .dev_release = mdiobus_release,
91};
92
93#if IS_ENABLED(CONFIG_OF_MDIO)
94/* Helper function for of_mdio_find_bus */
95static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
96{
97 return dev->of_node == mdio_bus_np;
98}
99/**
100 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
101 * @mdio_bus_np: Pointer to the mii_bus.
102 *
103 * Returns a pointer to the mii_bus, or NULL if none found.
104 *
105 * Because the association of a device_node and mii_bus is made via
106 * of_mdiobus_register(), the mii_bus cannot be found before it is
107 * registered with of_mdiobus_register().
108 *
109 */
110struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
111{
112 struct device *d;
113
114 if (!mdio_bus_np)
115 return NULL;
116
117 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
118 of_mdio_bus_match);
119
120 return d ? to_mii_bus(d) : NULL;
121}
122EXPORT_SYMBOL(of_mdio_find_bus);
123#endif
124
125/**
126 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
127 * @bus: target mii_bus
128 *
129 * Description: Called by a bus driver to bring up all the PHYs
130 * on a given bus, and attach them to the bus.
131 *
132 * Returns 0 on success or < 0 on error.
133 */
134int mdiobus_register(struct mii_bus *bus)
135{
136 int i, err;
137
138 if (NULL == bus || NULL == bus->name ||
139 NULL == bus->read || NULL == bus->write)
140 return -EINVAL;
141
142 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
143 bus->state != MDIOBUS_UNREGISTERED);
144
145 bus->dev.parent = bus->parent;
146 bus->dev.class = &mdio_bus_class;
147 bus->dev.groups = NULL;
148 dev_set_name(&bus->dev, "%s", bus->id);
149
150 err = device_register(&bus->dev);
151 if (err) {
152 pr_err("mii_bus %s failed to register\n", bus->id);
153 put_device(&bus->dev);
154 return -EINVAL;
155 }
156
157 mutex_init(&bus->mdio_lock);
158
159 if (bus->reset)
160 bus->reset(bus);
161
162 for (i = 0; i < PHY_MAX_ADDR; i++) {
163 if ((bus->phy_mask & (1 << i)) == 0) {
164 struct phy_device *phydev;
165
166 phydev = mdiobus_scan(bus, i);
167 if (IS_ERR(phydev)) {
168 err = PTR_ERR(phydev);
169 goto error;
170 }
171 }
172 }
173
174 bus->state = MDIOBUS_REGISTERED;
175 pr_info("%s: probed\n", bus->name);
176 return 0;
177
178error:
179 while (--i >= 0) {
180 if (bus->phy_map[i])
181 device_unregister(&bus->phy_map[i]->dev);
182 }
183 device_del(&bus->dev);
184 return err;
185}
186EXPORT_SYMBOL(mdiobus_register);
187
188void mdiobus_unregister(struct mii_bus *bus)
189{
190 int i;
191
192 BUG_ON(bus->state != MDIOBUS_REGISTERED);
193 bus->state = MDIOBUS_UNREGISTERED;
194
195 device_del(&bus->dev);
196 for (i = 0; i < PHY_MAX_ADDR; i++) {
197 if (bus->phy_map[i])
198 device_unregister(&bus->phy_map[i]->dev);
199 bus->phy_map[i] = NULL;
200 }
201}
202EXPORT_SYMBOL(mdiobus_unregister);
203
204/**
205 * mdiobus_free - free a struct mii_bus
206 * @bus: mii_bus to free
207 *
208 * This function releases the reference to the underlying device
209 * object in the mii_bus. If this is the last reference, the mii_bus
210 * will be freed.
211 */
212void mdiobus_free(struct mii_bus *bus)
213{
214 /* For compatibility with error handling in drivers. */
215 if (bus->state == MDIOBUS_ALLOCATED) {
216 kfree(bus);
217 return;
218 }
219
220 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
221 bus->state = MDIOBUS_RELEASED;
222
223 put_device(&bus->dev);
224}
225EXPORT_SYMBOL(mdiobus_free);
226
227struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
228{
229 struct phy_device *phydev;
230 int err;
231
232 phydev = get_phy_device(bus, addr, false);
233 if (IS_ERR(phydev) || phydev == NULL)
234 return phydev;
235
236 err = phy_device_register(phydev);
237 if (err) {
238 phy_device_free(phydev);
239 return NULL;
240 }
241
242 return phydev;
243}
244EXPORT_SYMBOL(mdiobus_scan);
245
246/**
247 * mdiobus_read - Convenience function for reading a given MII mgmt register
248 * @bus: the mii_bus struct
249 * @addr: the phy address
250 * @regnum: register number to read
251 *
252 * NOTE: MUST NOT be called from interrupt context,
253 * because the bus read/write functions may wait for an interrupt
254 * to conclude the operation.
255 */
256int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
257{
258 int retval;
259
260 BUG_ON(in_interrupt());
261
262 mutex_lock(&bus->mdio_lock);
263 retval = bus->read(bus, addr, regnum);
264 mutex_unlock(&bus->mdio_lock);
265
266 return retval;
267}
268EXPORT_SYMBOL(mdiobus_read);
269
270/**
271 * mdiobus_write - Convenience function for writing a given MII mgmt register
272 * @bus: the mii_bus struct
273 * @addr: the phy address
274 * @regnum: register number to write
275 * @val: value to write to @regnum
276 *
277 * NOTE: MUST NOT be called from interrupt context,
278 * because the bus read/write functions may wait for an interrupt
279 * to conclude the operation.
280 */
281int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
282{
283 int err;
284
285 BUG_ON(in_interrupt());
286
287 mutex_lock(&bus->mdio_lock);
288 err = bus->write(bus, addr, regnum, val);
289 mutex_unlock(&bus->mdio_lock);
290
291 return err;
292}
293EXPORT_SYMBOL(mdiobus_write);
294
295/**
296 * mdio_bus_match - determine if given PHY driver supports the given PHY device
297 * @dev: target PHY device
298 * @drv: given PHY driver
299 *
300 * Description: Given a PHY device, and a PHY driver, return 1 if
301 * the driver supports the device. Otherwise, return 0.
302 */
303static int mdio_bus_match(struct device *dev, struct device_driver *drv)
304{
305 struct phy_device *phydev = to_phy_device(dev);
306 struct phy_driver *phydrv = to_phy_driver(drv);
307
308 if (of_driver_match_device(dev, drv))
309 return 1;
310
311 if (phydrv->match_phy_device)
312 return phydrv->match_phy_device(phydev);
313
314 return (phydrv->phy_id & phydrv->phy_id_mask) ==
315 (phydev->phy_id & phydrv->phy_id_mask);
316}
317
318#ifdef CONFIG_PM
319
320static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
321{
322 struct device_driver *drv = phydev->dev.driver;
323 struct phy_driver *phydrv = to_phy_driver(drv);
324 struct net_device *netdev = phydev->attached_dev;
325
326 if (!drv || !phydrv->suspend)
327 return false;
328
329 /* PHY not attached? May suspend. */
330 if (!netdev)
331 return true;
332
333 /* Don't suspend PHY if the attched netdev parent may wakeup.
334 * The parent may point to a PCI device, as in tg3 driver.
335 */
336 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
337 return false;
338
339 /* Also don't suspend PHY if the netdev itself may wakeup. This
340 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
341 * e.g. SoC devices.
342 */
343 if (device_may_wakeup(&netdev->dev))
344 return false;
345
346 return true;
347}
348
349static int mdio_bus_suspend(struct device *dev)
350{
351 struct phy_driver *phydrv = to_phy_driver(dev->driver);
352 struct phy_device *phydev = to_phy_device(dev);
353
354 /* We must stop the state machine manually, otherwise it stops out of
355 * control, possibly with the phydev->lock held. Upon resume, netdev
356 * may call phy routines that try to grab the same lock, and that may
357 * lead to a deadlock.
358 */
359 if (phydev->attached_dev && phydev->adjust_link)
360 phy_stop_machine(phydev);
361
362 if (!mdio_bus_phy_may_suspend(phydev))
363 return 0;
364
365 return phydrv->suspend(phydev);
366}
367
368static int mdio_bus_resume(struct device *dev)
369{
370 struct phy_driver *phydrv = to_phy_driver(dev->driver);
371 struct phy_device *phydev = to_phy_device(dev);
372 int ret;
373
374 if (!mdio_bus_phy_may_suspend(phydev))
375 goto no_resume;
376
377 ret = phydrv->resume(phydev);
378 if (ret < 0)
379 return ret;
380
381no_resume:
382 if (phydev->attached_dev && phydev->adjust_link)
383 phy_start_machine(phydev);
384
385 return 0;
386}
387
388static int mdio_bus_restore(struct device *dev)
389{
390 struct phy_device *phydev = to_phy_device(dev);
391 struct net_device *netdev = phydev->attached_dev;
392 int ret;
393
394 if (!netdev)
395 return 0;
396
397 ret = phy_init_hw(phydev);
398 if (ret < 0)
399 return ret;
400
401 /* The PHY needs to renegotiate. */
402 phydev->link = 0;
403 phydev->state = PHY_UP;
404
405 phy_start_machine(phydev);
406
407 return 0;
408}
409
410static const struct dev_pm_ops mdio_bus_pm_ops = {
411 .suspend = mdio_bus_suspend,
412 .resume = mdio_bus_resume,
413 .freeze = mdio_bus_suspend,
414 .thaw = mdio_bus_resume,
415 .restore = mdio_bus_restore,
416};
417
418#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
419
420#else
421
422#define MDIO_BUS_PM_OPS NULL
423
424#endif /* CONFIG_PM */
425
426static ssize_t
427phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
428{
429 struct phy_device *phydev = to_phy_device(dev);
430
431 return sprintf(buf, "0x%.8lx\n", (unsigned long)phydev->phy_id);
432}
433static DEVICE_ATTR_RO(phy_id);
434
435static ssize_t
436phy_interface_show(struct device *dev, struct device_attribute *attr, char *buf)
437{
438 struct phy_device *phydev = to_phy_device(dev);
439
440 return sprintf(buf, "%s\n", phy_modes(phydev->interface));
441}
442static DEVICE_ATTR_RO(phy_interface);
443
444static ssize_t
445phy_has_fixups_show(struct device *dev, struct device_attribute *attr, char *buf)
446{
447 struct phy_device *phydev = to_phy_device(dev);
448
449 return sprintf(buf, "%d\n", phydev->has_fixups);
450}
451static DEVICE_ATTR_RO(phy_has_fixups);
452
453static struct attribute *mdio_dev_attrs[] = {
454 &dev_attr_phy_id.attr,
455 &dev_attr_phy_interface.attr,
456 &dev_attr_phy_has_fixups.attr,
457 NULL,
458};
459ATTRIBUTE_GROUPS(mdio_dev);
460
461struct bus_type mdio_bus_type = {
462 .name = "mdio_bus",
463 .match = mdio_bus_match,
464 .pm = MDIO_BUS_PM_OPS,
465 .dev_groups = mdio_dev_groups,
466};
467EXPORT_SYMBOL(mdio_bus_type);
468
469int __init mdio_bus_init(void)
470{
471 int ret;
472
473 ret = class_register(&mdio_bus_class);
474 if (!ret) {
475 ret = bus_register(&mdio_bus_type);
476 if (ret)
477 class_unregister(&mdio_bus_class);
478 }
479
480 return ret;
481}
482
483void mdio_bus_exit(void)
484{
485 class_unregister(&mdio_bus_class);
486 bus_unregister(&mdio_bus_type);
487}