1 // SPDX-License-Identifier: GPL-2.0+
6 * Copyright (c) 2004 Freescale Semiconductor, Inc.
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
21 #include <linux/kernel.h>
22 #include <linux/mii.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>
38 #define CREATE_TRACE_POINTS
39 #include <trace/events/mdio.h>
41 #include "mdio-boardinfo.h"
43 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
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);
51 if (mdiodev->reset_gpio)
52 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
57 static int mdiobus_register_reset(struct mdio_device *mdiodev)
59 struct reset_control *reset;
61 reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
63 return PTR_ERR(reset);
65 mdiodev->reset_ctrl = reset;
70 int mdiobus_register_device(struct mdio_device *mdiodev)
74 if (mdiodev->bus->mdio_map[mdiodev->addr])
77 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
78 err = mdiobus_register_gpiod(mdiodev);
82 err = mdiobus_register_reset(mdiodev);
86 /* Assert the reset signal */
87 mdio_device_reset(mdiodev, 1);
90 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
94 EXPORT_SYMBOL(mdiobus_register_device);
96 int mdiobus_unregister_device(struct mdio_device *mdiodev)
98 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
101 reset_control_put(mdiodev->reset_ctrl);
103 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
107 EXPORT_SYMBOL(mdiobus_unregister_device);
109 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
111 struct mdio_device *mdiodev = bus->mdio_map[addr];
116 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
119 return container_of(mdiodev, struct phy_device, mdio);
121 EXPORT_SYMBOL(mdiobus_get_phy);
123 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
125 return bus->mdio_map[addr];
127 EXPORT_SYMBOL(mdiobus_is_registered_device);
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.
134 * Description: called by a bus driver to allocate an mii_bus
135 * structure to fill in.
137 struct mii_bus *mdiobus_alloc_size(size_t size)
140 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
144 /* If we alloc extra space, it should be aligned */
146 alloc_size = aligned_size + size;
148 alloc_size = sizeof(*bus);
150 bus = kzalloc(alloc_size, GFP_KERNEL);
154 bus->state = MDIOBUS_ALLOCATED;
156 bus->priv = (void *)bus + aligned_size;
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);
166 EXPORT_SYMBOL(mdiobus_alloc_size);
169 * mdiobus_release - mii_bus device release callback
170 * @d: the target struct device that contains the mii_bus
172 * Description: called when the last reference to an mii_bus is
173 * dropped, to free the underlying memory.
175 static void mdiobus_release(struct device *d)
177 struct mii_bus *bus = to_mii_bus(d);
179 BUG_ON(bus->state != MDIOBUS_RELEASED &&
180 /* for compatibility with error handling in drivers */
181 bus->state != MDIOBUS_ALLOCATED);
185 struct mdio_bus_stat_attr {
187 unsigned int field_offset;
190 static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
192 const char *p = (const char *)s + offset;
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));
204 static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
209 for (i = 0; i < PHY_MAX_ADDR; i++)
210 val += mdio_bus_get_stat(&bus->stats[i], offset);
215 static ssize_t mdio_bus_stat_field_show(struct device *dev,
216 struct device_attribute *attr,
219 struct mii_bus *bus = to_mii_bus(dev);
220 struct mdio_bus_stat_attr *sattr;
221 struct dev_ext_attribute *eattr;
224 eattr = container_of(attr, struct dev_ext_attribute, attr);
228 val = mdio_bus_get_global_stat(bus, sattr->field_offset);
230 val = mdio_bus_get_stat(&bus->stats[sattr->addr],
231 sattr->field_offset);
233 return sprintf(buf, "%llu\n", val);
236 static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
237 struct device_attribute *attr,
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;
247 eattr = container_of(attr, struct dev_ext_attribute, attr);
250 val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);
252 return sprintf(buf, "%llu\n", val);
255 #define MDIO_BUS_STATS_ATTR_DECL(field, file) \
256 static struct dev_ext_attribute dev_attr_mdio_bus_##field = { \
257 .attr = { .attr = { .name = file, .mode = 0444 }, \
258 .show = mdio_bus_stat_field_show, \
260 .var = &((struct mdio_bus_stat_attr) { \
261 -1, offsetof(struct mdio_bus_stats, field) \
264 static 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, \
268 .var = &((struct mdio_bus_stat_attr) { \
269 -1, offsetof(struct mdio_bus_stats, field) \
273 #define MDIO_BUS_STATS_ATTR(field) \
274 MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
276 MDIO_BUS_STATS_ATTR(transfers);
277 MDIO_BUS_STATS_ATTR(errors);
278 MDIO_BUS_STATS_ATTR(writes);
279 MDIO_BUS_STATS_ATTR(reads);
281 #define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file) \
282 static 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, \
286 .var = &((struct mdio_bus_stat_attr) { \
287 addr, offsetof(struct mdio_bus_stats, field) \
291 #define MDIO_BUS_STATS_ADDR_ATTR(field, addr) \
292 MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, \
293 __stringify(field) "_" __stringify(addr))
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) \
301 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
302 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
303 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
304 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
305 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
306 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
307 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
308 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
309 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
310 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
311 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
312 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
313 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
314 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
315 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
316 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
317 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
318 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
319 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
320 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
321 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
322 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
323 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
324 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
325 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
326 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
327 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
328 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
329 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
330 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
331 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
332 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
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 \
340 static 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),
380 static const struct attribute_group mdio_bus_statistics_group = {
381 .name = "statistics",
382 .attrs = mdio_bus_statistics_attrs,
385 static const struct attribute_group *mdio_bus_groups[] = {
386 &mdio_bus_statistics_group,
390 static struct class mdio_bus_class = {
392 .dev_release = mdiobus_release,
393 .dev_groups = mdio_bus_groups,
397 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
398 * @mdio_name: The name of a mdiobus.
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.
404 struct mii_bus *mdio_find_bus(const char *mdio_name)
408 d = class_find_device_by_name(&mdio_bus_class, mdio_name);
409 return d ? to_mii_bus(d) : NULL;
411 EXPORT_SYMBOL(mdio_find_bus);
413 #if IS_ENABLED(CONFIG_OF_MDIO)
415 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
416 * @mdio_bus_np: Pointer to the mii_bus.
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.
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().
427 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
434 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
435 return d ? to_mii_bus(d) : NULL;
437 EXPORT_SYMBOL(of_mdio_find_bus);
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
445 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
446 struct mdio_device *mdiodev)
448 struct device *dev = &mdiodev->dev;
449 struct device_node *child;
451 if (dev->of_node || !bus->dev.of_node)
454 for_each_available_child_of_node(bus->dev.of_node, child) {
457 addr = of_mdio_parse_addr(dev, child);
461 if (addr == mdiodev->addr) {
462 device_set_node(dev, of_fwnode_handle(child));
467 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
468 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
469 struct mdio_device *mdiodev)
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
480 * Returns 0 on success or < 0 on error.
482 static int mdiobus_create_device(struct mii_bus *bus,
483 struct mdio_board_info *bi)
485 struct mdio_device *mdiodev;
488 mdiodev = mdio_device_create(bus, bi->mdio_addr);
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;
497 ret = mdio_device_register(mdiodev);
499 mdio_device_free(mdiodev);
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
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().
516 * Returns 0 on success or < 0 on error.
518 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
520 struct mdio_device *mdiodev;
522 struct gpio_desc *gpiod;
524 if (NULL == bus || NULL == bus->name ||
525 NULL == bus->read || NULL == bus->write)
528 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
529 bus->state != MDIOBUS_UNREGISTERED);
532 bus->dev.parent = bus->parent;
533 bus->dev.class = &mdio_bus_class;
534 bus->dev.groups = NULL;
535 dev_set_name(&bus->dev, "%s", bus->id);
537 err = device_register(&bus->dev);
539 pr_err("mii_bus %s failed to register\n", bus->id);
543 mutex_init(&bus->mdio_lock);
544 mutex_init(&bus->shared_lock);
546 /* assert bus level PHY GPIO reset */
547 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
549 err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
550 "mii_bus %s couldn't get reset GPIO\n",
552 device_del(&bus->dev);
555 bus->reset_gpiod = gpiod;
556 fsleep(bus->reset_delay_us);
557 gpiod_set_value_cansleep(gpiod, 0);
558 if (bus->reset_post_delay_us > 0)
559 fsleep(bus->reset_post_delay_us);
563 err = bus->reset(bus);
565 goto error_reset_gpiod;
568 for (i = 0; i < PHY_MAX_ADDR; i++) {
569 if ((bus->phy_mask & (1 << i)) == 0) {
570 struct phy_device *phydev;
572 phydev = mdiobus_scan(bus, i);
573 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
574 err = PTR_ERR(phydev);
580 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
582 bus->state = MDIOBUS_REGISTERED;
583 pr_info("%s: probed\n", bus->name);
588 mdiodev = bus->mdio_map[i];
592 mdiodev->device_remove(mdiodev);
593 mdiodev->device_free(mdiodev);
596 /* Put PHYs in RESET to save power */
597 if (bus->reset_gpiod)
598 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
600 device_del(&bus->dev);
603 EXPORT_SYMBOL(__mdiobus_register);
605 void mdiobus_unregister(struct mii_bus *bus)
607 struct mdio_device *mdiodev;
610 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
612 bus->state = MDIOBUS_UNREGISTERED;
614 for (i = 0; i < PHY_MAX_ADDR; i++) {
615 mdiodev = bus->mdio_map[i];
619 if (mdiodev->reset_gpio)
620 gpiod_put(mdiodev->reset_gpio);
622 mdiodev->device_remove(mdiodev);
623 mdiodev->device_free(mdiodev);
626 /* Put PHYs in RESET to save power */
627 if (bus->reset_gpiod)
628 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
630 device_del(&bus->dev);
632 EXPORT_SYMBOL(mdiobus_unregister);
635 * mdiobus_free - free a struct mii_bus
636 * @bus: mii_bus to free
638 * This function releases the reference to the underlying device
639 * object in the mii_bus. If this is the last reference, the mii_bus
642 void mdiobus_free(struct mii_bus *bus)
644 /* For compatibility with error handling in drivers. */
645 if (bus->state == MDIOBUS_ALLOCATED) {
650 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
651 bus->state = MDIOBUS_RELEASED;
653 put_device(&bus->dev);
655 EXPORT_SYMBOL(mdiobus_free);
658 * mdiobus_scan - scan a bus for MDIO devices.
659 * @bus: mii_bus to scan
660 * @addr: address on bus to scan
662 * This function scans the MDIO bus, looking for devices which can be
663 * identified using a vendor/product ID in registers 2 and 3. Not all
664 * MDIO devices have such registers, but PHY devices typically
665 * do. Hence this function assumes anything found is a PHY, or can be
666 * treated as a PHY. Other MDIO devices, such as switches, will
667 * probably not be found during the scan.
669 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
671 struct phy_device *phydev = ERR_PTR(-ENODEV);
674 switch (bus->probe_capabilities) {
677 phydev = get_phy_device(bus, addr, false);
680 phydev = get_phy_device(bus, addr, true);
682 case MDIOBUS_C22_C45:
683 phydev = get_phy_device(bus, addr, false);
685 phydev = get_phy_device(bus, addr, true);
693 * For DT, see if the auto-probed phy has a correspoding child
694 * in the bus node, and set the of_node pointer in this case.
696 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
698 err = phy_device_register(phydev);
700 phy_device_free(phydev);
701 return ERR_PTR(-ENODEV);
706 EXPORT_SYMBOL(mdiobus_scan);
708 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
711 u64_stats_update_begin(&stats->syncp);
713 u64_stats_inc(&stats->transfers);
715 u64_stats_inc(&stats->errors);
720 u64_stats_inc(&stats->reads);
722 u64_stats_inc(&stats->writes);
724 u64_stats_update_end(&stats->syncp);
729 * __mdiobus_read - Unlocked version of the mdiobus_read function
730 * @bus: the mii_bus struct
731 * @addr: the phy address
732 * @regnum: register number to read
734 * Read a MDIO bus register. Caller must hold the mdio bus lock.
736 * NOTE: MUST NOT be called from interrupt context.
738 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
742 lockdep_assert_held_once(&bus->mdio_lock);
744 retval = bus->read(bus, addr, regnum);
746 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
747 mdiobus_stats_acct(&bus->stats[addr], true, retval);
751 EXPORT_SYMBOL(__mdiobus_read);
754 * __mdiobus_write - Unlocked version of the mdiobus_write function
755 * @bus: the mii_bus struct
756 * @addr: the phy address
757 * @regnum: register number to write
758 * @val: value to write to @regnum
760 * Write a MDIO bus register. Caller must hold the mdio bus lock.
762 * NOTE: MUST NOT be called from interrupt context.
764 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
768 lockdep_assert_held_once(&bus->mdio_lock);
770 err = bus->write(bus, addr, regnum, val);
772 trace_mdio_access(bus, 0, addr, regnum, val, err);
773 mdiobus_stats_acct(&bus->stats[addr], false, err);
777 EXPORT_SYMBOL(__mdiobus_write);
780 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
781 * @bus: the mii_bus struct
782 * @addr: the phy address
783 * @regnum: register number to modify
784 * @mask: bit mask of bits to clear
785 * @set: bit mask of bits to set
787 * Read, modify, and if any change, write the register value back to the
788 * device. Any error returns a negative number.
790 * NOTE: MUST NOT be called from interrupt context.
792 int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
797 ret = __mdiobus_read(bus, addr, regnum);
801 new = (ret & ~mask) | set;
805 ret = __mdiobus_write(bus, addr, regnum, new);
807 return ret < 0 ? ret : 1;
809 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
812 * mdiobus_read_nested - Nested version of the mdiobus_read function
813 * @bus: the mii_bus struct
814 * @addr: the phy address
815 * @regnum: register number to read
817 * In case of nested MDIO bus access avoid lockdep false positives by
818 * using mutex_lock_nested().
820 * NOTE: MUST NOT be called from interrupt context,
821 * because the bus read/write functions may wait for an interrupt
822 * to conclude the operation.
824 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
828 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
829 retval = __mdiobus_read(bus, addr, regnum);
830 mutex_unlock(&bus->mdio_lock);
834 EXPORT_SYMBOL(mdiobus_read_nested);
837 * mdiobus_read - Convenience function for reading a given MII mgmt register
838 * @bus: the mii_bus struct
839 * @addr: the phy address
840 * @regnum: register number to read
842 * NOTE: MUST NOT be called from interrupt context,
843 * because the bus read/write functions may wait for an interrupt
844 * to conclude the operation.
846 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
850 mutex_lock(&bus->mdio_lock);
851 retval = __mdiobus_read(bus, addr, regnum);
852 mutex_unlock(&bus->mdio_lock);
856 EXPORT_SYMBOL(mdiobus_read);
859 * mdiobus_write_nested - Nested version of the mdiobus_write function
860 * @bus: the mii_bus struct
861 * @addr: the phy address
862 * @regnum: register number to write
863 * @val: value to write to @regnum
865 * In case of nested MDIO bus access avoid lockdep false positives by
866 * using mutex_lock_nested().
868 * NOTE: MUST NOT be called from interrupt context,
869 * because the bus read/write functions may wait for an interrupt
870 * to conclude the operation.
872 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
876 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
877 err = __mdiobus_write(bus, addr, regnum, val);
878 mutex_unlock(&bus->mdio_lock);
882 EXPORT_SYMBOL(mdiobus_write_nested);
885 * mdiobus_write - Convenience function for writing a given MII mgmt register
886 * @bus: the mii_bus struct
887 * @addr: the phy address
888 * @regnum: register number to write
889 * @val: value to write to @regnum
891 * NOTE: MUST NOT be called from interrupt context,
892 * because the bus read/write functions may wait for an interrupt
893 * to conclude the operation.
895 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
899 mutex_lock(&bus->mdio_lock);
900 err = __mdiobus_write(bus, addr, regnum, val);
901 mutex_unlock(&bus->mdio_lock);
905 EXPORT_SYMBOL(mdiobus_write);
908 * mdiobus_modify - Convenience function for modifying a given mdio device
910 * @bus: the mii_bus struct
911 * @addr: the phy address
912 * @regnum: register number to write
913 * @mask: bit mask of bits to clear
914 * @set: bit mask of bits to set
916 int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
920 mutex_lock(&bus->mdio_lock);
921 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
922 mutex_unlock(&bus->mdio_lock);
924 return err < 0 ? err : 0;
926 EXPORT_SYMBOL_GPL(mdiobus_modify);
929 * mdio_bus_match - determine if given MDIO driver supports the given
931 * @dev: target MDIO device
932 * @drv: given MDIO driver
934 * Description: Given a MDIO device, and a MDIO driver, return 1 if
935 * the driver supports the device. Otherwise, return 0. This may
936 * require calling the devices own match function, since different classes
937 * of MDIO devices have different match criteria.
939 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
941 struct mdio_device *mdio = to_mdio_device(dev);
943 if (of_driver_match_device(dev, drv))
947 return mdio->bus_match(dev, drv);
952 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
956 /* Some devices have extra OF data and an OF-style MODALIAS */
957 rc = of_device_uevent_modalias(dev, env);
964 static struct attribute *mdio_bus_device_statistics_attrs[] = {
965 &dev_attr_mdio_bus_device_transfers.attr.attr,
966 &dev_attr_mdio_bus_device_errors.attr.attr,
967 &dev_attr_mdio_bus_device_writes.attr.attr,
968 &dev_attr_mdio_bus_device_reads.attr.attr,
972 static const struct attribute_group mdio_bus_device_statistics_group = {
973 .name = "statistics",
974 .attrs = mdio_bus_device_statistics_attrs,
977 static const struct attribute_group *mdio_bus_dev_groups[] = {
978 &mdio_bus_device_statistics_group,
982 struct bus_type mdio_bus_type = {
984 .dev_groups = mdio_bus_dev_groups,
985 .match = mdio_bus_match,
986 .uevent = mdio_uevent,
988 EXPORT_SYMBOL(mdio_bus_type);
990 int __init mdio_bus_init(void)
994 ret = class_register(&mdio_bus_class);
996 ret = bus_register(&mdio_bus_type);
998 class_unregister(&mdio_bus_class);
1003 EXPORT_SYMBOL_GPL(mdio_bus_init);
1005 #if IS_ENABLED(CONFIG_PHYLIB)
1006 void mdio_bus_exit(void)
1008 class_unregister(&mdio_bus_class);
1009 bus_unregister(&mdio_bus_type);
1011 EXPORT_SYMBOL_GPL(mdio_bus_exit);
1013 module_init(mdio_bus_init);
1014 /* no module_exit, intentional */
1015 MODULE_LICENSE("GPL");
1016 MODULE_DESCRIPTION("MDIO bus/device layer");