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 = of_reset_control_get_exclusive(mdiodev->dev.of_node,
68 if (PTR_ERR(reset) == -ENOENT || PTR_ERR(reset) == -ENOTSUPP)
71 return PTR_ERR(reset);
74 mdiodev->reset_ctrl = reset;
79 int mdiobus_register_device(struct mdio_device *mdiodev)
83 if (mdiodev->bus->mdio_map[mdiodev->addr])
86 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
87 err = mdiobus_register_gpiod(mdiodev);
91 err = mdiobus_register_reset(mdiodev);
95 /* Assert the reset signal */
96 mdio_device_reset(mdiodev, 1);
99 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
103 EXPORT_SYMBOL(mdiobus_register_device);
105 int mdiobus_unregister_device(struct mdio_device *mdiodev)
107 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
110 reset_control_put(mdiodev->reset_ctrl);
112 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
116 EXPORT_SYMBOL(mdiobus_unregister_device);
118 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
120 struct mdio_device *mdiodev = bus->mdio_map[addr];
125 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
128 return container_of(mdiodev, struct phy_device, mdio);
130 EXPORT_SYMBOL(mdiobus_get_phy);
132 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
134 return bus->mdio_map[addr];
136 EXPORT_SYMBOL(mdiobus_is_registered_device);
139 * mdiobus_alloc_size - allocate a mii_bus structure
140 * @size: extra amount of memory to allocate for private storage.
141 * If non-zero, then bus->priv is points to that memory.
143 * Description: called by a bus driver to allocate an mii_bus
144 * structure to fill in.
146 struct mii_bus *mdiobus_alloc_size(size_t size)
149 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
153 /* If we alloc extra space, it should be aligned */
155 alloc_size = aligned_size + size;
157 alloc_size = sizeof(*bus);
159 bus = kzalloc(alloc_size, GFP_KERNEL);
163 bus->state = MDIOBUS_ALLOCATED;
165 bus->priv = (void *)bus + aligned_size;
167 /* Initialise the interrupts to polling */
168 for (i = 0; i < PHY_MAX_ADDR; i++)
169 bus->irq[i] = PHY_POLL;
173 EXPORT_SYMBOL(mdiobus_alloc_size);
175 static void _devm_mdiobus_free(struct device *dev, void *res)
177 mdiobus_free(*(struct mii_bus **)res);
180 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
182 struct mii_bus **r = res;
184 if (WARN_ON(!r || !*r))
191 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
192 * @dev: Device to allocate mii_bus for
193 * @sizeof_priv: Space to allocate for private structure.
195 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
196 * automatically freed on driver detach.
198 * If an mii_bus allocated with this function needs to be freed separately,
199 * devm_mdiobus_free() must be used.
202 * Pointer to allocated mii_bus on success, NULL on failure.
204 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
206 struct mii_bus **ptr, *bus;
208 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
212 /* use raw alloc_dr for kmalloc caller tracing */
213 bus = mdiobus_alloc_size(sizeof_priv);
216 devres_add(dev, ptr);
223 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
226 * devm_mdiobus_free - Resource-managed mdiobus_free()
227 * @dev: Device this mii_bus belongs to
228 * @bus: the mii_bus associated with the device
230 * Free mii_bus allocated with devm_mdiobus_alloc_size().
232 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
236 rc = devres_release(dev, _devm_mdiobus_free,
237 devm_mdiobus_match, bus);
240 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
243 * mdiobus_release - mii_bus device release callback
244 * @d: the target struct device that contains the mii_bus
246 * Description: called when the last reference to an mii_bus is
247 * dropped, to free the underlying memory.
249 static void mdiobus_release(struct device *d)
251 struct mii_bus *bus = to_mii_bus(d);
252 BUG_ON(bus->state != MDIOBUS_RELEASED &&
253 /* for compatibility with error handling in drivers */
254 bus->state != MDIOBUS_ALLOCATED);
258 static struct class mdio_bus_class = {
260 .dev_release = mdiobus_release,
263 #if IS_ENABLED(CONFIG_OF_MDIO)
265 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
266 * @mdio_bus_np: Pointer to the mii_bus.
268 * Returns a reference to the mii_bus, or NULL if none found. The
269 * embedded struct device will have its reference count incremented,
270 * and this must be put once the bus is finished with.
272 * Because the association of a device_node and mii_bus is made via
273 * of_mdiobus_register(), the mii_bus cannot be found before it is
274 * registered with of_mdiobus_register().
277 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
284 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
285 return d ? to_mii_bus(d) : NULL;
287 EXPORT_SYMBOL(of_mdio_find_bus);
289 /* Walk the list of subnodes of a mdio bus and look for a node that
290 * matches the mdio device's address with its 'reg' property. If
291 * found, set the of_node pointer for the mdio device. This allows
292 * auto-probed phy devices to be supplied with information passed in
295 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
296 struct mdio_device *mdiodev)
298 struct device *dev = &mdiodev->dev;
299 struct device_node *child;
301 if (dev->of_node || !bus->dev.of_node)
304 for_each_available_child_of_node(bus->dev.of_node, child) {
307 addr = of_mdio_parse_addr(dev, child);
311 if (addr == mdiodev->addr) {
312 dev->of_node = child;
313 dev->fwnode = of_fwnode_handle(child);
318 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
319 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
320 struct mdio_device *mdiodev)
326 * mdiobus_create_device_from_board_info - create a full MDIO device given
327 * a mdio_board_info structure
328 * @bus: MDIO bus to create the devices on
329 * @bi: mdio_board_info structure describing the devices
331 * Returns 0 on success or < 0 on error.
333 static int mdiobus_create_device(struct mii_bus *bus,
334 struct mdio_board_info *bi)
336 struct mdio_device *mdiodev;
339 mdiodev = mdio_device_create(bus, bi->mdio_addr);
343 strncpy(mdiodev->modalias, bi->modalias,
344 sizeof(mdiodev->modalias));
345 mdiodev->bus_match = mdio_device_bus_match;
346 mdiodev->dev.platform_data = (void *)bi->platform_data;
348 ret = mdio_device_register(mdiodev);
350 mdio_device_free(mdiodev);
356 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
357 * @bus: target mii_bus
358 * @owner: module containing bus accessor functions
360 * Description: Called by a bus driver to bring up all the PHYs
361 * on a given bus, and attach them to the bus. Drivers should use
362 * mdiobus_register() rather than __mdiobus_register() unless they
363 * need to pass a specific owner module. MDIO devices which are not
364 * PHYs will not be brought up by this function. They are expected to
365 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
367 * Returns 0 on success or < 0 on error.
369 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
371 struct mdio_device *mdiodev;
373 struct gpio_desc *gpiod;
375 if (NULL == bus || NULL == bus->name ||
376 NULL == bus->read || NULL == bus->write)
379 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
380 bus->state != MDIOBUS_UNREGISTERED);
383 bus->dev.parent = bus->parent;
384 bus->dev.class = &mdio_bus_class;
385 bus->dev.groups = NULL;
386 dev_set_name(&bus->dev, "%s", bus->id);
388 err = device_register(&bus->dev);
390 pr_err("mii_bus %s failed to register\n", bus->id);
394 mutex_init(&bus->mdio_lock);
396 /* de-assert bus level PHY GPIO reset */
397 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
399 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
401 device_del(&bus->dev);
402 return PTR_ERR(gpiod);
404 bus->reset_gpiod = gpiod;
406 gpiod_set_value_cansleep(gpiod, 1);
407 udelay(bus->reset_delay_us);
408 gpiod_set_value_cansleep(gpiod, 0);
414 for (i = 0; i < PHY_MAX_ADDR; i++) {
415 if ((bus->phy_mask & (1 << i)) == 0) {
416 struct phy_device *phydev;
418 phydev = mdiobus_scan(bus, i);
419 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
420 err = PTR_ERR(phydev);
426 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
428 bus->state = MDIOBUS_REGISTERED;
429 pr_info("%s: probed\n", bus->name);
434 mdiodev = bus->mdio_map[i];
438 mdiodev->device_remove(mdiodev);
439 mdiodev->device_free(mdiodev);
442 /* Put PHYs in RESET to save power */
443 if (bus->reset_gpiod)
444 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
446 device_del(&bus->dev);
449 EXPORT_SYMBOL(__mdiobus_register);
451 void mdiobus_unregister(struct mii_bus *bus)
453 struct mdio_device *mdiodev;
456 BUG_ON(bus->state != MDIOBUS_REGISTERED);
457 bus->state = MDIOBUS_UNREGISTERED;
459 for (i = 0; i < PHY_MAX_ADDR; i++) {
460 mdiodev = bus->mdio_map[i];
464 if (mdiodev->reset_gpio)
465 gpiod_put(mdiodev->reset_gpio);
467 mdiodev->device_remove(mdiodev);
468 mdiodev->device_free(mdiodev);
471 /* Put PHYs in RESET to save power */
472 if (bus->reset_gpiod)
473 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
475 device_del(&bus->dev);
477 EXPORT_SYMBOL(mdiobus_unregister);
480 * mdiobus_free - free a struct mii_bus
481 * @bus: mii_bus to free
483 * This function releases the reference to the underlying device
484 * object in the mii_bus. If this is the last reference, the mii_bus
487 void mdiobus_free(struct mii_bus *bus)
489 /* For compatibility with error handling in drivers. */
490 if (bus->state == MDIOBUS_ALLOCATED) {
495 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
496 bus->state = MDIOBUS_RELEASED;
498 put_device(&bus->dev);
500 EXPORT_SYMBOL(mdiobus_free);
503 * mdiobus_scan - scan a bus for MDIO devices.
504 * @bus: mii_bus to scan
505 * @addr: address on bus to scan
507 * This function scans the MDIO bus, looking for devices which can be
508 * identified using a vendor/product ID in registers 2 and 3. Not all
509 * MDIO devices have such registers, but PHY devices typically
510 * do. Hence this function assumes anything found is a PHY, or can be
511 * treated as a PHY. Other MDIO devices, such as switches, will
512 * probably not be found during the scan.
514 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
516 struct phy_device *phydev;
519 phydev = get_phy_device(bus, addr, false);
524 * For DT, see if the auto-probed phy has a correspoding child
525 * in the bus node, and set the of_node pointer in this case.
527 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
529 err = phy_device_register(phydev);
531 phy_device_free(phydev);
532 return ERR_PTR(-ENODEV);
537 EXPORT_SYMBOL(mdiobus_scan);
540 * __mdiobus_read - Unlocked version of the mdiobus_read function
541 * @bus: the mii_bus struct
542 * @addr: the phy address
543 * @regnum: register number to read
545 * Read a MDIO bus register. Caller must hold the mdio bus lock.
547 * NOTE: MUST NOT be called from interrupt context.
549 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
553 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
555 retval = bus->read(bus, addr, regnum);
557 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
561 EXPORT_SYMBOL(__mdiobus_read);
564 * __mdiobus_write - Unlocked version of the mdiobus_write function
565 * @bus: the mii_bus struct
566 * @addr: the phy address
567 * @regnum: register number to write
568 * @val: value to write to @regnum
570 * Write a MDIO bus register. Caller must hold the mdio bus lock.
572 * NOTE: MUST NOT be called from interrupt context.
574 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
578 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
580 err = bus->write(bus, addr, regnum, val);
582 trace_mdio_access(bus, 0, addr, regnum, val, err);
586 EXPORT_SYMBOL(__mdiobus_write);
589 * mdiobus_read_nested - Nested version of the mdiobus_read function
590 * @bus: the mii_bus struct
591 * @addr: the phy address
592 * @regnum: register number to read
594 * In case of nested MDIO bus access avoid lockdep false positives by
595 * using mutex_lock_nested().
597 * NOTE: MUST NOT be called from interrupt context,
598 * because the bus read/write functions may wait for an interrupt
599 * to conclude the operation.
601 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
605 BUG_ON(in_interrupt());
607 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
608 retval = __mdiobus_read(bus, addr, regnum);
609 mutex_unlock(&bus->mdio_lock);
613 EXPORT_SYMBOL(mdiobus_read_nested);
616 * mdiobus_read - Convenience function for reading a given MII mgmt register
617 * @bus: the mii_bus struct
618 * @addr: the phy address
619 * @regnum: register number to read
621 * NOTE: MUST NOT be called from interrupt context,
622 * because the bus read/write functions may wait for an interrupt
623 * to conclude the operation.
625 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
629 BUG_ON(in_interrupt());
631 mutex_lock(&bus->mdio_lock);
632 retval = __mdiobus_read(bus, addr, regnum);
633 mutex_unlock(&bus->mdio_lock);
637 EXPORT_SYMBOL(mdiobus_read);
640 * mdiobus_write_nested - Nested version of the mdiobus_write function
641 * @bus: the mii_bus struct
642 * @addr: the phy address
643 * @regnum: register number to write
644 * @val: value to write to @regnum
646 * In case of nested MDIO bus access avoid lockdep false positives by
647 * using mutex_lock_nested().
649 * NOTE: MUST NOT be called from interrupt context,
650 * because the bus read/write functions may wait for an interrupt
651 * to conclude the operation.
653 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
657 BUG_ON(in_interrupt());
659 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
660 err = __mdiobus_write(bus, addr, regnum, val);
661 mutex_unlock(&bus->mdio_lock);
665 EXPORT_SYMBOL(mdiobus_write_nested);
668 * mdiobus_write - Convenience function for writing a given MII mgmt register
669 * @bus: the mii_bus struct
670 * @addr: the phy address
671 * @regnum: register number to write
672 * @val: value to write to @regnum
674 * NOTE: MUST NOT be called from interrupt context,
675 * because the bus read/write functions may wait for an interrupt
676 * to conclude the operation.
678 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
682 BUG_ON(in_interrupt());
684 mutex_lock(&bus->mdio_lock);
685 err = __mdiobus_write(bus, addr, regnum, val);
686 mutex_unlock(&bus->mdio_lock);
690 EXPORT_SYMBOL(mdiobus_write);
693 * mdio_bus_match - determine if given MDIO driver supports the given
695 * @dev: target MDIO device
696 * @drv: given MDIO driver
698 * Description: Given a MDIO device, and a MDIO driver, return 1 if
699 * the driver supports the device. Otherwise, return 0. This may
700 * require calling the devices own match function, since different classes
701 * of MDIO devices have different match criteria.
703 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
705 struct mdio_device *mdio = to_mdio_device(dev);
707 if (of_driver_match_device(dev, drv))
711 return mdio->bus_match(dev, drv);
716 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
720 /* Some devices have extra OF data and an OF-style MODALIAS */
721 rc = of_device_uevent_modalias(dev, env);
728 struct bus_type mdio_bus_type = {
730 .match = mdio_bus_match,
731 .uevent = mdio_uevent,
733 EXPORT_SYMBOL(mdio_bus_type);
735 int __init mdio_bus_init(void)
739 ret = class_register(&mdio_bus_class);
741 ret = bus_register(&mdio_bus_type);
743 class_unregister(&mdio_bus_class);
748 EXPORT_SYMBOL_GPL(mdio_bus_init);
750 #if IS_ENABLED(CONFIG_PHYLIB)
751 void mdio_bus_exit(void)
753 class_unregister(&mdio_bus_class);
754 bus_unregister(&mdio_bus_type);
756 EXPORT_SYMBOL_GPL(mdio_bus_exit);
758 module_init(mdio_bus_init);
759 /* no module_exit, intentional */
760 MODULE_LICENSE("GPL");
761 MODULE_DESCRIPTION("MDIO bus/device layer");