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/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>
31 #include <linux/module.h>
32 #include <linux/mii.h>
33 #include <linux/ethtool.h>
34 #include <linux/phy.h>
36 #include <linux/uaccess.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)
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);
54 if (mdiodev->reset_gpio)
55 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
60 static int mdiobus_register_reset(struct mdio_device *mdiodev)
62 struct reset_control *reset = NULL;
64 if (mdiodev->dev.of_node)
65 reset = devm_reset_control_get_exclusive(&mdiodev->dev,
67 if (PTR_ERR(reset) == -ENOENT ||
68 PTR_ERR(reset) == -ENOTSUPP)
70 else if (IS_ERR(reset))
71 return PTR_ERR(reset);
73 mdiodev->reset_ctrl = reset;
78 int mdiobus_register_device(struct mdio_device *mdiodev)
82 if (mdiodev->bus->mdio_map[mdiodev->addr])
85 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
86 err = mdiobus_register_gpiod(mdiodev);
90 err = mdiobus_register_reset(mdiodev);
94 /* Assert the reset signal */
95 mdio_device_reset(mdiodev, 1);
98 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
102 EXPORT_SYMBOL(mdiobus_register_device);
104 int mdiobus_unregister_device(struct mdio_device *mdiodev)
106 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
109 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
113 EXPORT_SYMBOL(mdiobus_unregister_device);
115 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
117 struct mdio_device *mdiodev = bus->mdio_map[addr];
122 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
125 return container_of(mdiodev, struct phy_device, mdio);
127 EXPORT_SYMBOL(mdiobus_get_phy);
129 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
131 return bus->mdio_map[addr];
133 EXPORT_SYMBOL(mdiobus_is_registered_device);
136 * mdiobus_alloc_size - allocate a mii_bus structure
137 * @size: extra amount of memory to allocate for private storage.
138 * If non-zero, then bus->priv is points to that memory.
140 * Description: called by a bus driver to allocate an mii_bus
141 * structure to fill in.
143 struct mii_bus *mdiobus_alloc_size(size_t size)
146 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
150 /* If we alloc extra space, it should be aligned */
152 alloc_size = aligned_size + size;
154 alloc_size = sizeof(*bus);
156 bus = kzalloc(alloc_size, GFP_KERNEL);
160 bus->state = MDIOBUS_ALLOCATED;
162 bus->priv = (void *)bus + aligned_size;
164 /* Initialise the interrupts to polling */
165 for (i = 0; i < PHY_MAX_ADDR; i++)
166 bus->irq[i] = PHY_POLL;
170 EXPORT_SYMBOL(mdiobus_alloc_size);
172 static void _devm_mdiobus_free(struct device *dev, void *res)
174 mdiobus_free(*(struct mii_bus **)res);
177 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
179 struct mii_bus **r = res;
181 if (WARN_ON(!r || !*r))
188 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
189 * @dev: Device to allocate mii_bus for
190 * @sizeof_priv: Space to allocate for private structure.
192 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
193 * automatically freed on driver detach.
195 * If an mii_bus allocated with this function needs to be freed separately,
196 * devm_mdiobus_free() must be used.
199 * Pointer to allocated mii_bus on success, NULL on failure.
201 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
203 struct mii_bus **ptr, *bus;
205 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
209 /* use raw alloc_dr for kmalloc caller tracing */
210 bus = mdiobus_alloc_size(sizeof_priv);
213 devres_add(dev, ptr);
220 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
223 * devm_mdiobus_free - Resource-managed mdiobus_free()
224 * @dev: Device this mii_bus belongs to
225 * @bus: the mii_bus associated with the device
227 * Free mii_bus allocated with devm_mdiobus_alloc_size().
229 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
233 rc = devres_release(dev, _devm_mdiobus_free,
234 devm_mdiobus_match, bus);
237 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
240 * mdiobus_release - mii_bus device release callback
241 * @d: the target struct device that contains the mii_bus
243 * Description: called when the last reference to an mii_bus is
244 * dropped, to free the underlying memory.
246 static void mdiobus_release(struct device *d)
248 struct mii_bus *bus = to_mii_bus(d);
249 BUG_ON(bus->state != MDIOBUS_RELEASED &&
250 /* for compatibility with error handling in drivers */
251 bus->state != MDIOBUS_ALLOCATED);
255 static struct class mdio_bus_class = {
257 .dev_release = mdiobus_release,
260 #if IS_ENABLED(CONFIG_OF_MDIO)
262 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
263 * @mdio_bus_np: Pointer to the mii_bus.
265 * Returns a reference to the mii_bus, or NULL if none found. The
266 * embedded struct device will have its reference count incremented,
267 * and this must be put once the bus is finished with.
269 * Because the association of a device_node and mii_bus is made via
270 * of_mdiobus_register(), the mii_bus cannot be found before it is
271 * registered with of_mdiobus_register().
274 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
281 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
282 return d ? to_mii_bus(d) : NULL;
284 EXPORT_SYMBOL(of_mdio_find_bus);
286 /* Walk the list of subnodes of a mdio bus and look for a node that
287 * matches the mdio device's address with its 'reg' property. If
288 * found, set the of_node pointer for the mdio device. This allows
289 * auto-probed phy devices to be supplied with information passed in
292 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
293 struct mdio_device *mdiodev)
295 struct device *dev = &mdiodev->dev;
296 struct device_node *child;
298 if (dev->of_node || !bus->dev.of_node)
301 for_each_available_child_of_node(bus->dev.of_node, child) {
304 addr = of_mdio_parse_addr(dev, child);
308 if (addr == mdiodev->addr) {
309 dev->of_node = child;
310 dev->fwnode = of_fwnode_handle(child);
315 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
316 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
317 struct mdio_device *mdiodev)
323 * mdiobus_create_device_from_board_info - create a full MDIO device given
324 * a mdio_board_info structure
325 * @bus: MDIO bus to create the devices on
326 * @bi: mdio_board_info structure describing the devices
328 * Returns 0 on success or < 0 on error.
330 static int mdiobus_create_device(struct mii_bus *bus,
331 struct mdio_board_info *bi)
333 struct mdio_device *mdiodev;
336 mdiodev = mdio_device_create(bus, bi->mdio_addr);
340 strncpy(mdiodev->modalias, bi->modalias,
341 sizeof(mdiodev->modalias));
342 mdiodev->bus_match = mdio_device_bus_match;
343 mdiodev->dev.platform_data = (void *)bi->platform_data;
345 ret = mdio_device_register(mdiodev);
347 mdio_device_free(mdiodev);
353 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
354 * @bus: target mii_bus
355 * @owner: module containing bus accessor functions
357 * Description: Called by a bus driver to bring up all the PHYs
358 * on a given bus, and attach them to the bus. Drivers should use
359 * mdiobus_register() rather than __mdiobus_register() unless they
360 * need to pass a specific owner module. MDIO devices which are not
361 * PHYs will not be brought up by this function. They are expected to
362 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
364 * Returns 0 on success or < 0 on error.
366 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
368 struct mdio_device *mdiodev;
370 struct gpio_desc *gpiod;
372 if (NULL == bus || NULL == bus->name ||
373 NULL == bus->read || NULL == bus->write)
376 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
377 bus->state != MDIOBUS_UNREGISTERED);
380 bus->dev.parent = bus->parent;
381 bus->dev.class = &mdio_bus_class;
382 bus->dev.groups = NULL;
383 dev_set_name(&bus->dev, "%s", bus->id);
385 err = device_register(&bus->dev);
387 pr_err("mii_bus %s failed to register\n", bus->id);
391 mutex_init(&bus->mdio_lock);
393 /* de-assert bus level PHY GPIO reset */
394 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
396 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
398 device_del(&bus->dev);
399 return PTR_ERR(gpiod);
401 bus->reset_gpiod = gpiod;
403 gpiod_set_value_cansleep(gpiod, 1);
404 udelay(bus->reset_delay_us);
405 gpiod_set_value_cansleep(gpiod, 0);
411 for (i = 0; i < PHY_MAX_ADDR; i++) {
412 if ((bus->phy_mask & (1 << i)) == 0) {
413 struct phy_device *phydev;
415 phydev = mdiobus_scan(bus, i);
416 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
417 err = PTR_ERR(phydev);
423 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
425 bus->state = MDIOBUS_REGISTERED;
426 pr_info("%s: probed\n", bus->name);
431 mdiodev = bus->mdio_map[i];
435 mdiodev->device_remove(mdiodev);
436 mdiodev->device_free(mdiodev);
439 /* Put PHYs in RESET to save power */
440 if (bus->reset_gpiod)
441 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
443 device_del(&bus->dev);
446 EXPORT_SYMBOL(__mdiobus_register);
448 void mdiobus_unregister(struct mii_bus *bus)
450 struct mdio_device *mdiodev;
453 BUG_ON(bus->state != MDIOBUS_REGISTERED);
454 bus->state = MDIOBUS_UNREGISTERED;
456 for (i = 0; i < PHY_MAX_ADDR; i++) {
457 mdiodev = bus->mdio_map[i];
461 if (mdiodev->reset_gpio)
462 gpiod_put(mdiodev->reset_gpio);
464 mdiodev->device_remove(mdiodev);
465 mdiodev->device_free(mdiodev);
468 /* Put PHYs in RESET to save power */
469 if (bus->reset_gpiod)
470 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
472 device_del(&bus->dev);
474 EXPORT_SYMBOL(mdiobus_unregister);
477 * mdiobus_free - free a struct mii_bus
478 * @bus: mii_bus to free
480 * This function releases the reference to the underlying device
481 * object in the mii_bus. If this is the last reference, the mii_bus
484 void mdiobus_free(struct mii_bus *bus)
486 /* For compatibility with error handling in drivers. */
487 if (bus->state == MDIOBUS_ALLOCATED) {
492 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
493 bus->state = MDIOBUS_RELEASED;
495 put_device(&bus->dev);
497 EXPORT_SYMBOL(mdiobus_free);
500 * mdiobus_scan - scan a bus for MDIO devices.
501 * @bus: mii_bus to scan
502 * @addr: address on bus to scan
504 * This function scans the MDIO bus, looking for devices which can be
505 * identified using a vendor/product ID in registers 2 and 3. Not all
506 * MDIO devices have such registers, but PHY devices typically
507 * do. Hence this function assumes anything found is a PHY, or can be
508 * treated as a PHY. Other MDIO devices, such as switches, will
509 * probably not be found during the scan.
511 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
513 struct phy_device *phydev;
516 phydev = get_phy_device(bus, addr, false);
521 * For DT, see if the auto-probed phy has a correspoding child
522 * in the bus node, and set the of_node pointer in this case.
524 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
526 err = phy_device_register(phydev);
528 phy_device_free(phydev);
529 return ERR_PTR(-ENODEV);
534 EXPORT_SYMBOL(mdiobus_scan);
537 * __mdiobus_read - Unlocked version of the mdiobus_read function
538 * @bus: the mii_bus struct
539 * @addr: the phy address
540 * @regnum: register number to read
542 * Read a MDIO bus register. Caller must hold the mdio bus lock.
544 * NOTE: MUST NOT be called from interrupt context.
546 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
550 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
552 retval = bus->read(bus, addr, regnum);
554 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
558 EXPORT_SYMBOL(__mdiobus_read);
561 * __mdiobus_write - Unlocked version of the mdiobus_write function
562 * @bus: the mii_bus struct
563 * @addr: the phy address
564 * @regnum: register number to write
565 * @val: value to write to @regnum
567 * Write a MDIO bus register. Caller must hold the mdio bus lock.
569 * NOTE: MUST NOT be called from interrupt context.
571 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
575 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
577 err = bus->write(bus, addr, regnum, val);
579 trace_mdio_access(bus, 0, addr, regnum, val, err);
583 EXPORT_SYMBOL(__mdiobus_write);
586 * mdiobus_read_nested - Nested version of the mdiobus_read function
587 * @bus: the mii_bus struct
588 * @addr: the phy address
589 * @regnum: register number to read
591 * In case of nested MDIO bus access avoid lockdep false positives by
592 * using mutex_lock_nested().
594 * NOTE: MUST NOT be called from interrupt context,
595 * because the bus read/write functions may wait for an interrupt
596 * to conclude the operation.
598 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
602 BUG_ON(in_interrupt());
604 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
605 retval = __mdiobus_read(bus, addr, regnum);
606 mutex_unlock(&bus->mdio_lock);
610 EXPORT_SYMBOL(mdiobus_read_nested);
613 * mdiobus_read - Convenience function for reading a given MII mgmt register
614 * @bus: the mii_bus struct
615 * @addr: the phy address
616 * @regnum: register number to read
618 * NOTE: MUST NOT be called from interrupt context,
619 * because the bus read/write functions may wait for an interrupt
620 * to conclude the operation.
622 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
626 BUG_ON(in_interrupt());
628 mutex_lock(&bus->mdio_lock);
629 retval = __mdiobus_read(bus, addr, regnum);
630 mutex_unlock(&bus->mdio_lock);
634 EXPORT_SYMBOL(mdiobus_read);
637 * mdiobus_write_nested - Nested version of the mdiobus_write function
638 * @bus: the mii_bus struct
639 * @addr: the phy address
640 * @regnum: register number to write
641 * @val: value to write to @regnum
643 * In case of nested MDIO bus access avoid lockdep false positives by
644 * using mutex_lock_nested().
646 * NOTE: MUST NOT be called from interrupt context,
647 * because the bus read/write functions may wait for an interrupt
648 * to conclude the operation.
650 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
654 BUG_ON(in_interrupt());
656 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
657 err = __mdiobus_write(bus, addr, regnum, val);
658 mutex_unlock(&bus->mdio_lock);
662 EXPORT_SYMBOL(mdiobus_write_nested);
665 * mdiobus_write - Convenience function for writing a given MII mgmt register
666 * @bus: the mii_bus struct
667 * @addr: the phy address
668 * @regnum: register number to write
669 * @val: value to write to @regnum
671 * NOTE: MUST NOT be called from interrupt context,
672 * because the bus read/write functions may wait for an interrupt
673 * to conclude the operation.
675 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
679 BUG_ON(in_interrupt());
681 mutex_lock(&bus->mdio_lock);
682 err = __mdiobus_write(bus, addr, regnum, val);
683 mutex_unlock(&bus->mdio_lock);
687 EXPORT_SYMBOL(mdiobus_write);
690 * mdio_bus_match - determine if given MDIO driver supports the given
692 * @dev: target MDIO device
693 * @drv: given MDIO driver
695 * Description: Given a MDIO device, and a MDIO driver, return 1 if
696 * the driver supports the device. Otherwise, return 0. This may
697 * require calling the devices own match function, since different classes
698 * of MDIO devices have different match criteria.
700 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
702 struct mdio_device *mdio = to_mdio_device(dev);
704 if (of_driver_match_device(dev, drv))
708 return mdio->bus_match(dev, drv);
713 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
717 /* Some devices have extra OF data and an OF-style MODALIAS */
718 rc = of_device_uevent_modalias(dev, env);
725 struct bus_type mdio_bus_type = {
727 .match = mdio_bus_match,
728 .uevent = mdio_uevent,
730 EXPORT_SYMBOL(mdio_bus_type);
732 int __init mdio_bus_init(void)
736 ret = class_register(&mdio_bus_class);
738 ret = bus_register(&mdio_bus_type);
740 class_unregister(&mdio_bus_class);
745 EXPORT_SYMBOL_GPL(mdio_bus_init);
747 #if IS_ENABLED(CONFIG_PHYLIB)
748 void mdio_bus_exit(void)
750 class_unregister(&mdio_bus_class);
751 bus_unregister(&mdio_bus_type);
753 EXPORT_SYMBOL_GPL(mdio_bus_exit);
755 module_init(mdio_bus_init);
756 /* no module_exit, intentional */
757 MODULE_LICENSE("GPL");
758 MODULE_DESCRIPTION("MDIO bus/device layer");