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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/kernel.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <linux/unistd.h>
15#include <linux/slab.h>
16#include <linux/interrupt.h>
17#include <linux/init.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/gpio.h>
21#include <linux/gpio/consumer.h>
22#include <linux/of_device.h>
23#include <linux/of_mdio.h>
24#include <linux/of_gpio.h>
25#include <linux/netdevice.h>
26#include <linux/etherdevice.h>
27#include <linux/reset.h>
28#include <linux/skbuff.h>
29#include <linux/spinlock.h>
30#include <linux/mm.h>
31#include <linux/module.h>
32#include <linux/mii.h>
33#include <linux/ethtool.h>
34#include <linux/phy.h>
35#include <linux/io.h>
36#include <linux/uaccess.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 int error;
46
47 /* Deassert the optional reset signal */
48 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
49 "reset", GPIOD_OUT_LOW);
50 error = PTR_ERR_OR_ZERO(mdiodev->reset_gpio);
51 if (error)
52 return error;
53
54 if (mdiodev->reset_gpio)
55 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
56
57 return 0;
58}
59
60static int mdiobus_register_reset(struct mdio_device *mdiodev)
61{
62 struct reset_control *reset = NULL;
63
64 if (mdiodev->dev.of_node)
65 reset = devm_reset_control_get_exclusive(&mdiodev->dev,
66 "phy");
67 if (IS_ERR(reset)) {
68 if (PTR_ERR(reset) == -ENOENT || PTR_ERR(reset) == -ENOTSUPP)
69 reset = NULL;
70 else
71 return PTR_ERR(reset);
72 }
73
74 mdiodev->reset_ctrl = reset;
75
76 return 0;
77}
78
79int mdiobus_register_device(struct mdio_device *mdiodev)
80{
81 int err;
82
83 if (mdiodev->bus->mdio_map[mdiodev->addr])
84 return -EBUSY;
85
86 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
87 err = mdiobus_register_gpiod(mdiodev);
88 if (err)
89 return err;
90
91 err = mdiobus_register_reset(mdiodev);
92 if (err)
93 return err;
94
95 /* Assert the reset signal */
96 mdio_device_reset(mdiodev, 1);
97 }
98
99 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
100
101 return 0;
102}
103EXPORT_SYMBOL(mdiobus_register_device);
104
105int mdiobus_unregister_device(struct mdio_device *mdiodev)
106{
107 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
108 return -EINVAL;
109
110 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
111
112 return 0;
113}
114EXPORT_SYMBOL(mdiobus_unregister_device);
115
116struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
117{
118 struct mdio_device *mdiodev = bus->mdio_map[addr];
119
120 if (!mdiodev)
121 return NULL;
122
123 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
124 return NULL;
125
126 return container_of(mdiodev, struct phy_device, mdio);
127}
128EXPORT_SYMBOL(mdiobus_get_phy);
129
130bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
131{
132 return bus->mdio_map[addr];
133}
134EXPORT_SYMBOL(mdiobus_is_registered_device);
135
136/**
137 * mdiobus_alloc_size - allocate a mii_bus structure
138 * @size: extra amount of memory to allocate for private storage.
139 * If non-zero, then bus->priv is points to that memory.
140 *
141 * Description: called by a bus driver to allocate an mii_bus
142 * structure to fill in.
143 */
144struct mii_bus *mdiobus_alloc_size(size_t size)
145{
146 struct mii_bus *bus;
147 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
148 size_t alloc_size;
149 int i;
150
151 /* If we alloc extra space, it should be aligned */
152 if (size)
153 alloc_size = aligned_size + size;
154 else
155 alloc_size = sizeof(*bus);
156
157 bus = kzalloc(alloc_size, GFP_KERNEL);
158 if (!bus)
159 return NULL;
160
161 bus->state = MDIOBUS_ALLOCATED;
162 if (size)
163 bus->priv = (void *)bus + aligned_size;
164
165 /* Initialise the interrupts to polling */
166 for (i = 0; i < PHY_MAX_ADDR; i++)
167 bus->irq[i] = PHY_POLL;
168
169 return bus;
170}
171EXPORT_SYMBOL(mdiobus_alloc_size);
172
173static void _devm_mdiobus_free(struct device *dev, void *res)
174{
175 mdiobus_free(*(struct mii_bus **)res);
176}
177
178static int devm_mdiobus_match(struct device *dev, void *res, void *data)
179{
180 struct mii_bus **r = res;
181
182 if (WARN_ON(!r || !*r))
183 return 0;
184
185 return *r == data;
186}
187
188/**
189 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
190 * @dev: Device to allocate mii_bus for
191 * @sizeof_priv: Space to allocate for private structure.
192 *
193 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
194 * automatically freed on driver detach.
195 *
196 * If an mii_bus allocated with this function needs to be freed separately,
197 * devm_mdiobus_free() must be used.
198 *
199 * RETURNS:
200 * Pointer to allocated mii_bus on success, NULL on failure.
201 */
202struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
203{
204 struct mii_bus **ptr, *bus;
205
206 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
207 if (!ptr)
208 return NULL;
209
210 /* use raw alloc_dr for kmalloc caller tracing */
211 bus = mdiobus_alloc_size(sizeof_priv);
212 if (bus) {
213 *ptr = bus;
214 devres_add(dev, ptr);
215 } else {
216 devres_free(ptr);
217 }
218
219 return bus;
220}
221EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
222
223/**
224 * devm_mdiobus_free - Resource-managed mdiobus_free()
225 * @dev: Device this mii_bus belongs to
226 * @bus: the mii_bus associated with the device
227 *
228 * Free mii_bus allocated with devm_mdiobus_alloc_size().
229 */
230void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
231{
232 int rc;
233
234 rc = devres_release(dev, _devm_mdiobus_free,
235 devm_mdiobus_match, bus);
236 WARN_ON(rc);
237}
238EXPORT_SYMBOL_GPL(devm_mdiobus_free);
239
240/**
241 * mdiobus_release - mii_bus device release callback
242 * @d: the target struct device that contains the mii_bus
243 *
244 * Description: called when the last reference to an mii_bus is
245 * dropped, to free the underlying memory.
246 */
247static void mdiobus_release(struct device *d)
248{
249 struct mii_bus *bus = to_mii_bus(d);
250 BUG_ON(bus->state != MDIOBUS_RELEASED &&
251 /* for compatibility with error handling in drivers */
252 bus->state != MDIOBUS_ALLOCATED);
253 kfree(bus);
254}
255
256static struct class mdio_bus_class = {
257 .name = "mdio_bus",
258 .dev_release = mdiobus_release,
259};
260
261#if IS_ENABLED(CONFIG_OF_MDIO)
262/**
263 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
264 * @mdio_bus_np: Pointer to the mii_bus.
265 *
266 * Returns a reference to the mii_bus, or NULL if none found. The
267 * embedded struct device will have its reference count incremented,
268 * and this must be put once the bus is finished with.
269 *
270 * Because the association of a device_node and mii_bus is made via
271 * of_mdiobus_register(), the mii_bus cannot be found before it is
272 * registered with of_mdiobus_register().
273 *
274 */
275struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
276{
277 struct device *d;
278
279 if (!mdio_bus_np)
280 return NULL;
281
282 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
283 return d ? to_mii_bus(d) : NULL;
284}
285EXPORT_SYMBOL(of_mdio_find_bus);
286
287/* Walk the list of subnodes of a mdio bus and look for a node that
288 * matches the mdio device's address with its 'reg' property. If
289 * found, set the of_node pointer for the mdio device. This allows
290 * auto-probed phy devices to be supplied with information passed in
291 * via DT.
292 */
293static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
294 struct mdio_device *mdiodev)
295{
296 struct device *dev = &mdiodev->dev;
297 struct device_node *child;
298
299 if (dev->of_node || !bus->dev.of_node)
300 return;
301
302 for_each_available_child_of_node(bus->dev.of_node, child) {
303 int addr;
304
305 addr = of_mdio_parse_addr(dev, child);
306 if (addr < 0)
307 continue;
308
309 if (addr == mdiodev->addr) {
310 dev->of_node = child;
311 dev->fwnode = of_fwnode_handle(child);
312 return;
313 }
314 }
315}
316#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
317static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
318 struct mdio_device *mdiodev)
319{
320}
321#endif
322
323/**
324 * mdiobus_create_device_from_board_info - create a full MDIO device given
325 * a mdio_board_info structure
326 * @bus: MDIO bus to create the devices on
327 * @bi: mdio_board_info structure describing the devices
328 *
329 * Returns 0 on success or < 0 on error.
330 */
331static int mdiobus_create_device(struct mii_bus *bus,
332 struct mdio_board_info *bi)
333{
334 struct mdio_device *mdiodev;
335 int ret = 0;
336
337 mdiodev = mdio_device_create(bus, bi->mdio_addr);
338 if (IS_ERR(mdiodev))
339 return -ENODEV;
340
341 strncpy(mdiodev->modalias, bi->modalias,
342 sizeof(mdiodev->modalias));
343 mdiodev->bus_match = mdio_device_bus_match;
344 mdiodev->dev.platform_data = (void *)bi->platform_data;
345
346 ret = mdio_device_register(mdiodev);
347 if (ret)
348 mdio_device_free(mdiodev);
349
350 return ret;
351}
352
353/**
354 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
355 * @bus: target mii_bus
356 * @owner: module containing bus accessor functions
357 *
358 * Description: Called by a bus driver to bring up all the PHYs
359 * on a given bus, and attach them to the bus. Drivers should use
360 * mdiobus_register() rather than __mdiobus_register() unless they
361 * need to pass a specific owner module. MDIO devices which are not
362 * PHYs will not be brought up by this function. They are expected to
363 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
364 *
365 * Returns 0 on success or < 0 on error.
366 */
367int __mdiobus_register(struct mii_bus *bus, struct module *owner)
368{
369 struct mdio_device *mdiodev;
370 int i, err;
371 struct gpio_desc *gpiod;
372
373 if (NULL == bus || NULL == bus->name ||
374 NULL == bus->read || NULL == bus->write)
375 return -EINVAL;
376
377 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
378 bus->state != MDIOBUS_UNREGISTERED);
379
380 bus->owner = owner;
381 bus->dev.parent = bus->parent;
382 bus->dev.class = &mdio_bus_class;
383 bus->dev.groups = NULL;
384 dev_set_name(&bus->dev, "%s", bus->id);
385
386 err = device_register(&bus->dev);
387 if (err) {
388 pr_err("mii_bus %s failed to register\n", bus->id);
389 return -EINVAL;
390 }
391
392 mutex_init(&bus->mdio_lock);
393
394 /* de-assert bus level PHY GPIO reset */
395 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
396 if (IS_ERR(gpiod)) {
397 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
398 bus->id);
399 device_del(&bus->dev);
400 return PTR_ERR(gpiod);
401 } else if (gpiod) {
402 bus->reset_gpiod = gpiod;
403
404 gpiod_set_value_cansleep(gpiod, 1);
405 udelay(bus->reset_delay_us);
406 gpiod_set_value_cansleep(gpiod, 0);
407 }
408
409 if (bus->reset)
410 bus->reset(bus);
411
412 for (i = 0; i < PHY_MAX_ADDR; i++) {
413 if ((bus->phy_mask & (1 << i)) == 0) {
414 struct phy_device *phydev;
415
416 phydev = mdiobus_scan(bus, i);
417 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
418 err = PTR_ERR(phydev);
419 goto error;
420 }
421 }
422 }
423
424 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
425
426 bus->state = MDIOBUS_REGISTERED;
427 pr_info("%s: probed\n", bus->name);
428 return 0;
429
430error:
431 while (--i >= 0) {
432 mdiodev = bus->mdio_map[i];
433 if (!mdiodev)
434 continue;
435
436 mdiodev->device_remove(mdiodev);
437 mdiodev->device_free(mdiodev);
438 }
439
440 /* Put PHYs in RESET to save power */
441 if (bus->reset_gpiod)
442 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
443
444 device_del(&bus->dev);
445 return err;
446}
447EXPORT_SYMBOL(__mdiobus_register);
448
449void mdiobus_unregister(struct mii_bus *bus)
450{
451 struct mdio_device *mdiodev;
452 int i;
453
454 BUG_ON(bus->state != MDIOBUS_REGISTERED);
455 bus->state = MDIOBUS_UNREGISTERED;
456
457 for (i = 0; i < PHY_MAX_ADDR; i++) {
458 mdiodev = bus->mdio_map[i];
459 if (!mdiodev)
460 continue;
461
462 if (mdiodev->reset_gpio)
463 gpiod_put(mdiodev->reset_gpio);
464
465 mdiodev->device_remove(mdiodev);
466 mdiodev->device_free(mdiodev);
467 }
468
469 /* Put PHYs in RESET to save power */
470 if (bus->reset_gpiod)
471 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
472
473 device_del(&bus->dev);
474}
475EXPORT_SYMBOL(mdiobus_unregister);
476
477/**
478 * mdiobus_free - free a struct mii_bus
479 * @bus: mii_bus to free
480 *
481 * This function releases the reference to the underlying device
482 * object in the mii_bus. If this is the last reference, the mii_bus
483 * will be freed.
484 */
485void mdiobus_free(struct mii_bus *bus)
486{
487 /* For compatibility with error handling in drivers. */
488 if (bus->state == MDIOBUS_ALLOCATED) {
489 kfree(bus);
490 return;
491 }
492
493 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
494 bus->state = MDIOBUS_RELEASED;
495
496 put_device(&bus->dev);
497}
498EXPORT_SYMBOL(mdiobus_free);
499
500/**
501 * mdiobus_scan - scan a bus for MDIO devices.
502 * @bus: mii_bus to scan
503 * @addr: address on bus to scan
504 *
505 * This function scans the MDIO bus, looking for devices which can be
506 * identified using a vendor/product ID in registers 2 and 3. Not all
507 * MDIO devices have such registers, but PHY devices typically
508 * do. Hence this function assumes anything found is a PHY, or can be
509 * treated as a PHY. Other MDIO devices, such as switches, will
510 * probably not be found during the scan.
511 */
512struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
513{
514 struct phy_device *phydev;
515 int err;
516
517 phydev = get_phy_device(bus, addr, false);
518 if (IS_ERR(phydev))
519 return phydev;
520
521 /*
522 * For DT, see if the auto-probed phy has a correspoding child
523 * in the bus node, and set the of_node pointer in this case.
524 */
525 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
526
527 err = phy_device_register(phydev);
528 if (err) {
529 phy_device_free(phydev);
530 return ERR_PTR(-ENODEV);
531 }
532
533 return phydev;
534}
535EXPORT_SYMBOL(mdiobus_scan);
536
537/**
538 * __mdiobus_read - Unlocked version of the mdiobus_read function
539 * @bus: the mii_bus struct
540 * @addr: the phy address
541 * @regnum: register number to read
542 *
543 * Read a MDIO bus register. Caller must hold the mdio bus lock.
544 *
545 * NOTE: MUST NOT be called from interrupt context.
546 */
547int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
548{
549 int retval;
550
551 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
552
553 retval = bus->read(bus, addr, regnum);
554
555 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
556
557 return retval;
558}
559EXPORT_SYMBOL(__mdiobus_read);
560
561/**
562 * __mdiobus_write - Unlocked version of the mdiobus_write function
563 * @bus: the mii_bus struct
564 * @addr: the phy address
565 * @regnum: register number to write
566 * @val: value to write to @regnum
567 *
568 * Write a MDIO bus register. Caller must hold the mdio bus lock.
569 *
570 * NOTE: MUST NOT be called from interrupt context.
571 */
572int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
573{
574 int err;
575
576 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
577
578 err = bus->write(bus, addr, regnum, val);
579
580 trace_mdio_access(bus, 0, addr, regnum, val, err);
581
582 return err;
583}
584EXPORT_SYMBOL(__mdiobus_write);
585
586/**
587 * mdiobus_read_nested - Nested version of the mdiobus_read function
588 * @bus: the mii_bus struct
589 * @addr: the phy address
590 * @regnum: register number to read
591 *
592 * In case of nested MDIO bus access avoid lockdep false positives by
593 * using mutex_lock_nested().
594 *
595 * NOTE: MUST NOT be called from interrupt context,
596 * because the bus read/write functions may wait for an interrupt
597 * to conclude the operation.
598 */
599int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
600{
601 int retval;
602
603 BUG_ON(in_interrupt());
604
605 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
606 retval = __mdiobus_read(bus, addr, regnum);
607 mutex_unlock(&bus->mdio_lock);
608
609 return retval;
610}
611EXPORT_SYMBOL(mdiobus_read_nested);
612
613/**
614 * mdiobus_read - Convenience function for reading a given MII mgmt register
615 * @bus: the mii_bus struct
616 * @addr: the phy address
617 * @regnum: register number to read
618 *
619 * NOTE: MUST NOT be called from interrupt context,
620 * because the bus read/write functions may wait for an interrupt
621 * to conclude the operation.
622 */
623int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
624{
625 int retval;
626
627 BUG_ON(in_interrupt());
628
629 mutex_lock(&bus->mdio_lock);
630 retval = __mdiobus_read(bus, addr, regnum);
631 mutex_unlock(&bus->mdio_lock);
632
633 return retval;
634}
635EXPORT_SYMBOL(mdiobus_read);
636
637/**
638 * mdiobus_write_nested - Nested version of the mdiobus_write function
639 * @bus: the mii_bus struct
640 * @addr: the phy address
641 * @regnum: register number to write
642 * @val: value to write to @regnum
643 *
644 * In case of nested MDIO bus access avoid lockdep false positives by
645 * using mutex_lock_nested().
646 *
647 * NOTE: MUST NOT be called from interrupt context,
648 * because the bus read/write functions may wait for an interrupt
649 * to conclude the operation.
650 */
651int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
652{
653 int err;
654
655 BUG_ON(in_interrupt());
656
657 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
658 err = __mdiobus_write(bus, addr, regnum, val);
659 mutex_unlock(&bus->mdio_lock);
660
661 return err;
662}
663EXPORT_SYMBOL(mdiobus_write_nested);
664
665/**
666 * mdiobus_write - Convenience function for writing a given MII mgmt register
667 * @bus: the mii_bus struct
668 * @addr: the phy address
669 * @regnum: register number to write
670 * @val: value to write to @regnum
671 *
672 * NOTE: MUST NOT be called from interrupt context,
673 * because the bus read/write functions may wait for an interrupt
674 * to conclude the operation.
675 */
676int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
677{
678 int err;
679
680 BUG_ON(in_interrupt());
681
682 mutex_lock(&bus->mdio_lock);
683 err = __mdiobus_write(bus, addr, regnum, val);
684 mutex_unlock(&bus->mdio_lock);
685
686 return err;
687}
688EXPORT_SYMBOL(mdiobus_write);
689
690/**
691 * mdio_bus_match - determine if given MDIO driver supports the given
692 * MDIO device
693 * @dev: target MDIO device
694 * @drv: given MDIO driver
695 *
696 * Description: Given a MDIO device, and a MDIO driver, return 1 if
697 * the driver supports the device. Otherwise, return 0. This may
698 * require calling the devices own match function, since different classes
699 * of MDIO devices have different match criteria.
700 */
701static int mdio_bus_match(struct device *dev, struct device_driver *drv)
702{
703 struct mdio_device *mdio = to_mdio_device(dev);
704
705 if (of_driver_match_device(dev, drv))
706 return 1;
707
708 if (mdio->bus_match)
709 return mdio->bus_match(dev, drv);
710
711 return 0;
712}
713
714static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
715{
716 int rc;
717
718 /* Some devices have extra OF data and an OF-style MODALIAS */
719 rc = of_device_uevent_modalias(dev, env);
720 if (rc != -ENODEV)
721 return rc;
722
723 return 0;
724}
725
726struct bus_type mdio_bus_type = {
727 .name = "mdio_bus",
728 .match = mdio_bus_match,
729 .uevent = mdio_uevent,
730};
731EXPORT_SYMBOL(mdio_bus_type);
732
733int __init mdio_bus_init(void)
734{
735 int ret;
736
737 ret = class_register(&mdio_bus_class);
738 if (!ret) {
739 ret = bus_register(&mdio_bus_type);
740 if (ret)
741 class_unregister(&mdio_bus_class);
742 }
743
744 return ret;
745}
746EXPORT_SYMBOL_GPL(mdio_bus_init);
747
748#if IS_ENABLED(CONFIG_PHYLIB)
749void mdio_bus_exit(void)
750{
751 class_unregister(&mdio_bus_class);
752 bus_unregister(&mdio_bus_type);
753}
754EXPORT_SYMBOL_GPL(mdio_bus_exit);
755#else
756module_init(mdio_bus_init);
757/* no module_exit, intentional */
758MODULE_LICENSE("GPL");
759MODULE_DESCRIPTION("MDIO bus/device layer");
760#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
41int mdiobus_register_device(struct mdio_device *mdiodev)
42{
43 if (mdiodev->bus->mdio_map[mdiodev->addr])
44 return -EBUSY;
45
46 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
47
48 return 0;
49}
50EXPORT_SYMBOL(mdiobus_register_device);
51
52int mdiobus_unregister_device(struct mdio_device *mdiodev)
53{
54 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
55 return -EINVAL;
56
57 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
58
59 return 0;
60}
61EXPORT_SYMBOL(mdiobus_unregister_device);
62
63struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
64{
65 struct mdio_device *mdiodev = bus->mdio_map[addr];
66
67 if (!mdiodev)
68 return NULL;
69
70 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
71 return NULL;
72
73 return container_of(mdiodev, struct phy_device, mdio);
74}
75EXPORT_SYMBOL(mdiobus_get_phy);
76
77bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
78{
79 return bus->mdio_map[addr];
80}
81EXPORT_SYMBOL(mdiobus_is_registered_device);
82
83/**
84 * mdiobus_alloc_size - allocate a mii_bus structure
85 * @size: extra amount of memory to allocate for private storage.
86 * If non-zero, then bus->priv is points to that memory.
87 *
88 * Description: called by a bus driver to allocate an mii_bus
89 * structure to fill in.
90 */
91struct mii_bus *mdiobus_alloc_size(size_t size)
92{
93 struct mii_bus *bus;
94 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
95 size_t alloc_size;
96 int i;
97
98 /* If we alloc extra space, it should be aligned */
99 if (size)
100 alloc_size = aligned_size + size;
101 else
102 alloc_size = sizeof(*bus);
103
104 bus = kzalloc(alloc_size, GFP_KERNEL);
105 if (!bus)
106 return NULL;
107
108 bus->state = MDIOBUS_ALLOCATED;
109 if (size)
110 bus->priv = (void *)bus + aligned_size;
111
112 /* Initialise the interrupts to polling */
113 for (i = 0; i < PHY_MAX_ADDR; i++)
114 bus->irq[i] = PHY_POLL;
115
116 return bus;
117}
118EXPORT_SYMBOL(mdiobus_alloc_size);
119
120static void _devm_mdiobus_free(struct device *dev, void *res)
121{
122 mdiobus_free(*(struct mii_bus **)res);
123}
124
125static int devm_mdiobus_match(struct device *dev, void *res, void *data)
126{
127 struct mii_bus **r = res;
128
129 if (WARN_ON(!r || !*r))
130 return 0;
131
132 return *r == data;
133}
134
135/**
136 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
137 * @dev: Device to allocate mii_bus for
138 * @sizeof_priv: Space to allocate for private structure.
139 *
140 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
141 * automatically freed on driver detach.
142 *
143 * If an mii_bus allocated with this function needs to be freed separately,
144 * devm_mdiobus_free() must be used.
145 *
146 * RETURNS:
147 * Pointer to allocated mii_bus on success, NULL on failure.
148 */
149struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
150{
151 struct mii_bus **ptr, *bus;
152
153 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
154 if (!ptr)
155 return NULL;
156
157 /* use raw alloc_dr for kmalloc caller tracing */
158 bus = mdiobus_alloc_size(sizeof_priv);
159 if (bus) {
160 *ptr = bus;
161 devres_add(dev, ptr);
162 } else {
163 devres_free(ptr);
164 }
165
166 return bus;
167}
168EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
169
170/**
171 * devm_mdiobus_free - Resource-managed mdiobus_free()
172 * @dev: Device this mii_bus belongs to
173 * @bus: the mii_bus associated with the device
174 *
175 * Free mii_bus allocated with devm_mdiobus_alloc_size().
176 */
177void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
178{
179 int rc;
180
181 rc = devres_release(dev, _devm_mdiobus_free,
182 devm_mdiobus_match, bus);
183 WARN_ON(rc);
184}
185EXPORT_SYMBOL_GPL(devm_mdiobus_free);
186
187/**
188 * mdiobus_release - mii_bus device release callback
189 * @d: the target struct device that contains the mii_bus
190 *
191 * Description: called when the last reference to an mii_bus is
192 * dropped, to free the underlying memory.
193 */
194static void mdiobus_release(struct device *d)
195{
196 struct mii_bus *bus = to_mii_bus(d);
197 BUG_ON(bus->state != MDIOBUS_RELEASED &&
198 /* for compatibility with error handling in drivers */
199 bus->state != MDIOBUS_ALLOCATED);
200 kfree(bus);
201}
202
203static struct class mdio_bus_class = {
204 .name = "mdio_bus",
205 .dev_release = mdiobus_release,
206};
207
208#if IS_ENABLED(CONFIG_OF_MDIO)
209/* Helper function for of_mdio_find_bus */
210static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
211{
212 return dev->of_node == mdio_bus_np;
213}
214/**
215 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
216 * @mdio_bus_np: Pointer to the mii_bus.
217 *
218 * Returns a reference to the mii_bus, or NULL if none found. The
219 * embedded struct device will have its reference count incremented,
220 * and this must be put once the bus is finished with.
221 *
222 * Because the association of a device_node and mii_bus is made via
223 * of_mdiobus_register(), the mii_bus cannot be found before it is
224 * registered with of_mdiobus_register().
225 *
226 */
227struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
228{
229 struct device *d;
230
231 if (!mdio_bus_np)
232 return NULL;
233
234 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
235 of_mdio_bus_match);
236
237 return d ? to_mii_bus(d) : NULL;
238}
239EXPORT_SYMBOL(of_mdio_find_bus);
240
241/* Walk the list of subnodes of a mdio bus and look for a node that
242 * matches the mdio device's address with its 'reg' property. If
243 * found, set the of_node pointer for the mdio device. This allows
244 * auto-probed phy devices to be supplied with information passed in
245 * via DT.
246 */
247static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
248 struct mdio_device *mdiodev)
249{
250 struct device *dev = &mdiodev->dev;
251 struct device_node *child;
252
253 if (dev->of_node || !bus->dev.of_node)
254 return;
255
256 for_each_available_child_of_node(bus->dev.of_node, child) {
257 int addr;
258 int ret;
259
260 ret = of_property_read_u32(child, "reg", &addr);
261 if (ret < 0) {
262 dev_err(dev, "%s has invalid MDIO address\n",
263 child->full_name);
264 continue;
265 }
266
267 /* A MDIO device must have a reg property in the range [0-31] */
268 if (addr >= PHY_MAX_ADDR) {
269 dev_err(dev, "%s MDIO address %i is too large\n",
270 child->full_name, addr);
271 continue;
272 }
273
274 if (addr == mdiodev->addr) {
275 dev->of_node = child;
276 return;
277 }
278 }
279}
280#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
281static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
282 struct mdio_device *mdiodev)
283{
284}
285#endif
286
287/**
288 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
289 * @bus: target mii_bus
290 * @owner: module containing bus accessor functions
291 *
292 * Description: Called by a bus driver to bring up all the PHYs
293 * on a given bus, and attach them to the bus. Drivers should use
294 * mdiobus_register() rather than __mdiobus_register() unless they
295 * need to pass a specific owner module. MDIO devices which are not
296 * PHYs will not be brought up by this function. They are expected to
297 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
298 *
299 * Returns 0 on success or < 0 on error.
300 */
301int __mdiobus_register(struct mii_bus *bus, struct module *owner)
302{
303 struct mdio_device *mdiodev;
304 int i, err;
305
306 if (NULL == bus || NULL == bus->name ||
307 NULL == bus->read || NULL == bus->write)
308 return -EINVAL;
309
310 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
311 bus->state != MDIOBUS_UNREGISTERED);
312
313 bus->owner = owner;
314 bus->dev.parent = bus->parent;
315 bus->dev.class = &mdio_bus_class;
316 bus->dev.groups = NULL;
317 dev_set_name(&bus->dev, "%s", bus->id);
318
319 err = device_register(&bus->dev);
320 if (err) {
321 pr_err("mii_bus %s failed to register\n", bus->id);
322 put_device(&bus->dev);
323 return -EINVAL;
324 }
325
326 mutex_init(&bus->mdio_lock);
327
328 if (bus->reset)
329 bus->reset(bus);
330
331 for (i = 0; i < PHY_MAX_ADDR; i++) {
332 if ((bus->phy_mask & (1 << i)) == 0) {
333 struct phy_device *phydev;
334
335 phydev = mdiobus_scan(bus, i);
336 if (IS_ERR(phydev)) {
337 err = PTR_ERR(phydev);
338 goto error;
339 }
340 }
341 }
342
343 bus->state = MDIOBUS_REGISTERED;
344 pr_info("%s: probed\n", bus->name);
345 return 0;
346
347error:
348 while (--i >= 0) {
349 mdiodev = bus->mdio_map[i];
350 if (!mdiodev)
351 continue;
352
353 mdiodev->device_remove(mdiodev);
354 mdiodev->device_free(mdiodev);
355 }
356 device_del(&bus->dev);
357 return err;
358}
359EXPORT_SYMBOL(__mdiobus_register);
360
361void mdiobus_unregister(struct mii_bus *bus)
362{
363 struct mdio_device *mdiodev;
364 int i;
365
366 BUG_ON(bus->state != MDIOBUS_REGISTERED);
367 bus->state = MDIOBUS_UNREGISTERED;
368
369 for (i = 0; i < PHY_MAX_ADDR; i++) {
370 mdiodev = bus->mdio_map[i];
371 if (!mdiodev)
372 continue;
373
374 mdiodev->device_remove(mdiodev);
375 mdiodev->device_free(mdiodev);
376 }
377 device_del(&bus->dev);
378}
379EXPORT_SYMBOL(mdiobus_unregister);
380
381/**
382 * mdiobus_free - free a struct mii_bus
383 * @bus: mii_bus to free
384 *
385 * This function releases the reference to the underlying device
386 * object in the mii_bus. If this is the last reference, the mii_bus
387 * will be freed.
388 */
389void mdiobus_free(struct mii_bus *bus)
390{
391 /* For compatibility with error handling in drivers. */
392 if (bus->state == MDIOBUS_ALLOCATED) {
393 kfree(bus);
394 return;
395 }
396
397 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
398 bus->state = MDIOBUS_RELEASED;
399
400 put_device(&bus->dev);
401}
402EXPORT_SYMBOL(mdiobus_free);
403
404/**
405 * mdiobus_scan - scan a bus for MDIO devices.
406 * @bus: mii_bus to scan
407 * @addr: address on bus to scan
408 *
409 * This function scans the MDIO bus, looking for devices which can be
410 * identified using a vendor/product ID in registers 2 and 3. Not all
411 * MDIO devices have such registers, but PHY devices typically
412 * do. Hence this function assumes anything found is a PHY, or can be
413 * treated as a PHY. Other MDIO devices, such as switches, will
414 * probably not be found during the scan.
415 */
416struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
417{
418 struct phy_device *phydev;
419 int err;
420
421 phydev = get_phy_device(bus, addr, false);
422 if (IS_ERR(phydev) || phydev == NULL)
423 return phydev;
424
425 /*
426 * For DT, see if the auto-probed phy has a correspoding child
427 * in the bus node, and set the of_node pointer in this case.
428 */
429 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
430
431 err = phy_device_register(phydev);
432 if (err) {
433 phy_device_free(phydev);
434 return NULL;
435 }
436
437 return phydev;
438}
439EXPORT_SYMBOL(mdiobus_scan);
440
441/**
442 * mdiobus_read_nested - Nested version of the mdiobus_read function
443 * @bus: the mii_bus struct
444 * @addr: the phy address
445 * @regnum: register number to read
446 *
447 * In case of nested MDIO bus access avoid lockdep false positives by
448 * using mutex_lock_nested().
449 *
450 * NOTE: MUST NOT be called from interrupt context,
451 * because the bus read/write functions may wait for an interrupt
452 * to conclude the operation.
453 */
454int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
455{
456 int retval;
457
458 BUG_ON(in_interrupt());
459
460 mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
461 retval = bus->read(bus, addr, regnum);
462 mutex_unlock(&bus->mdio_lock);
463
464 return retval;
465}
466EXPORT_SYMBOL(mdiobus_read_nested);
467
468/**
469 * mdiobus_read - Convenience function for reading a given MII mgmt register
470 * @bus: the mii_bus struct
471 * @addr: the phy address
472 * @regnum: register number to read
473 *
474 * NOTE: MUST NOT be called from interrupt context,
475 * because the bus read/write functions may wait for an interrupt
476 * to conclude the operation.
477 */
478int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
479{
480 int retval;
481
482 BUG_ON(in_interrupt());
483
484 mutex_lock(&bus->mdio_lock);
485 retval = bus->read(bus, addr, regnum);
486 mutex_unlock(&bus->mdio_lock);
487
488 return retval;
489}
490EXPORT_SYMBOL(mdiobus_read);
491
492/**
493 * mdiobus_write_nested - Nested version of the mdiobus_write function
494 * @bus: the mii_bus struct
495 * @addr: the phy address
496 * @regnum: register number to write
497 * @val: value to write to @regnum
498 *
499 * In case of nested MDIO bus access avoid lockdep false positives by
500 * using mutex_lock_nested().
501 *
502 * NOTE: MUST NOT be called from interrupt context,
503 * because the bus read/write functions may wait for an interrupt
504 * to conclude the operation.
505 */
506int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
507{
508 int err;
509
510 BUG_ON(in_interrupt());
511
512 mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
513 err = bus->write(bus, addr, regnum, val);
514 mutex_unlock(&bus->mdio_lock);
515
516 return err;
517}
518EXPORT_SYMBOL(mdiobus_write_nested);
519
520/**
521 * mdiobus_write - Convenience function for writing a given MII mgmt register
522 * @bus: the mii_bus struct
523 * @addr: the phy address
524 * @regnum: register number to write
525 * @val: value to write to @regnum
526 *
527 * NOTE: MUST NOT be called from interrupt context,
528 * because the bus read/write functions may wait for an interrupt
529 * to conclude the operation.
530 */
531int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
532{
533 int err;
534
535 BUG_ON(in_interrupt());
536
537 mutex_lock(&bus->mdio_lock);
538 err = bus->write(bus, addr, regnum, val);
539 mutex_unlock(&bus->mdio_lock);
540
541 return err;
542}
543EXPORT_SYMBOL(mdiobus_write);
544
545/**
546 * mdio_bus_match - determine if given MDIO driver supports the given
547 * MDIO device
548 * @dev: target MDIO device
549 * @drv: given MDIO driver
550 *
551 * Description: Given a MDIO device, and a MDIO driver, return 1 if
552 * the driver supports the device. Otherwise, return 0. This may
553 * require calling the devices own match function, since different classes
554 * of MDIO devices have different match criteria.
555 */
556static int mdio_bus_match(struct device *dev, struct device_driver *drv)
557{
558 struct mdio_device *mdio = to_mdio_device(dev);
559
560 if (of_driver_match_device(dev, drv))
561 return 1;
562
563 if (mdio->bus_match)
564 return mdio->bus_match(dev, drv);
565
566 return 0;
567}
568
569#ifdef CONFIG_PM
570static int mdio_bus_suspend(struct device *dev)
571{
572 struct mdio_device *mdio = to_mdio_device(dev);
573
574 if (mdio->pm_ops && mdio->pm_ops->suspend)
575 return mdio->pm_ops->suspend(dev);
576
577 return 0;
578}
579
580static int mdio_bus_resume(struct device *dev)
581{
582 struct mdio_device *mdio = to_mdio_device(dev);
583
584 if (mdio->pm_ops && mdio->pm_ops->resume)
585 return mdio->pm_ops->resume(dev);
586
587 return 0;
588}
589
590static int mdio_bus_restore(struct device *dev)
591{
592 struct mdio_device *mdio = to_mdio_device(dev);
593
594 if (mdio->pm_ops && mdio->pm_ops->restore)
595 return mdio->pm_ops->restore(dev);
596
597 return 0;
598}
599
600static const struct dev_pm_ops mdio_bus_pm_ops = {
601 .suspend = mdio_bus_suspend,
602 .resume = mdio_bus_resume,
603 .freeze = mdio_bus_suspend,
604 .thaw = mdio_bus_resume,
605 .restore = mdio_bus_restore,
606};
607
608#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
609
610#else
611
612#define MDIO_BUS_PM_OPS NULL
613
614#endif /* CONFIG_PM */
615
616struct bus_type mdio_bus_type = {
617 .name = "mdio_bus",
618 .match = mdio_bus_match,
619 .pm = MDIO_BUS_PM_OPS,
620};
621EXPORT_SYMBOL(mdio_bus_type);
622
623int __init mdio_bus_init(void)
624{
625 int ret;
626
627 ret = class_register(&mdio_bus_class);
628 if (!ret) {
629 ret = bus_register(&mdio_bus_type);
630 if (ret)
631 class_unregister(&mdio_bus_class);
632 }
633
634 return ret;
635}
636
637void mdio_bus_exit(void)
638{
639 class_unregister(&mdio_bus_class);
640 bus_unregister(&mdio_bus_type);
641}