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)
45 struct gpio_desc *gpiod = NULL;
47 /* Deassert the optional reset signal */
48 if (mdiodev->dev.of_node)
49 gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
50 "reset-gpios", 0, GPIOD_OUT_LOW,
53 if (PTR_ERR(gpiod) == -ENOENT || PTR_ERR(gpiod) == -ENOSYS)
56 return PTR_ERR(gpiod);
59 mdiodev->reset_gpio = gpiod;
64 static int mdiobus_register_reset(struct mdio_device *mdiodev)
66 struct reset_control *reset = NULL;
68 if (mdiodev->dev.of_node)
69 reset = devm_reset_control_get_exclusive(&mdiodev->dev,
71 if (PTR_ERR(reset) == -ENOENT ||
72 PTR_ERR(reset) == -ENOTSUPP)
74 else if (IS_ERR(reset))
75 return PTR_ERR(reset);
77 mdiodev->reset_ctrl = reset;
82 int mdiobus_register_device(struct mdio_device *mdiodev)
86 if (mdiodev->bus->mdio_map[mdiodev->addr])
89 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
90 err = mdiobus_register_gpiod(mdiodev);
94 err = mdiobus_register_reset(mdiodev);
98 /* Assert the reset signal */
99 mdio_device_reset(mdiodev, 1);
102 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
106 EXPORT_SYMBOL(mdiobus_register_device);
108 int mdiobus_unregister_device(struct mdio_device *mdiodev)
110 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
113 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
117 EXPORT_SYMBOL(mdiobus_unregister_device);
119 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
121 struct mdio_device *mdiodev = bus->mdio_map[addr];
126 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
129 return container_of(mdiodev, struct phy_device, mdio);
131 EXPORT_SYMBOL(mdiobus_get_phy);
133 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
135 return bus->mdio_map[addr];
137 EXPORT_SYMBOL(mdiobus_is_registered_device);
140 * mdiobus_alloc_size - allocate a mii_bus structure
141 * @size: extra amount of memory to allocate for private storage.
142 * If non-zero, then bus->priv is points to that memory.
144 * Description: called by a bus driver to allocate an mii_bus
145 * structure to fill in.
147 struct mii_bus *mdiobus_alloc_size(size_t size)
150 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
154 /* If we alloc extra space, it should be aligned */
156 alloc_size = aligned_size + size;
158 alloc_size = sizeof(*bus);
160 bus = kzalloc(alloc_size, GFP_KERNEL);
164 bus->state = MDIOBUS_ALLOCATED;
166 bus->priv = (void *)bus + aligned_size;
168 /* Initialise the interrupts to polling */
169 for (i = 0; i < PHY_MAX_ADDR; i++)
170 bus->irq[i] = PHY_POLL;
174 EXPORT_SYMBOL(mdiobus_alloc_size);
176 static void _devm_mdiobus_free(struct device *dev, void *res)
178 mdiobus_free(*(struct mii_bus **)res);
181 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
183 struct mii_bus **r = res;
185 if (WARN_ON(!r || !*r))
192 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
193 * @dev: Device to allocate mii_bus for
194 * @sizeof_priv: Space to allocate for private structure.
196 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
197 * automatically freed on driver detach.
199 * If an mii_bus allocated with this function needs to be freed separately,
200 * devm_mdiobus_free() must be used.
203 * Pointer to allocated mii_bus on success, NULL on failure.
205 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
207 struct mii_bus **ptr, *bus;
209 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
213 /* use raw alloc_dr for kmalloc caller tracing */
214 bus = mdiobus_alloc_size(sizeof_priv);
217 devres_add(dev, ptr);
224 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
227 * devm_mdiobus_free - Resource-managed mdiobus_free()
228 * @dev: Device this mii_bus belongs to
229 * @bus: the mii_bus associated with the device
231 * Free mii_bus allocated with devm_mdiobus_alloc_size().
233 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
237 rc = devres_release(dev, _devm_mdiobus_free,
238 devm_mdiobus_match, bus);
241 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
244 * mdiobus_release - mii_bus device release callback
245 * @d: the target struct device that contains the mii_bus
247 * Description: called when the last reference to an mii_bus is
248 * dropped, to free the underlying memory.
250 static void mdiobus_release(struct device *d)
252 struct mii_bus *bus = to_mii_bus(d);
253 BUG_ON(bus->state != MDIOBUS_RELEASED &&
254 /* for compatibility with error handling in drivers */
255 bus->state != MDIOBUS_ALLOCATED);
259 static struct class mdio_bus_class = {
261 .dev_release = mdiobus_release,
264 #if IS_ENABLED(CONFIG_OF_MDIO)
265 /* Helper function for of_mdio_find_bus */
266 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
268 return dev->of_node == mdio_bus_np;
271 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
272 * @mdio_bus_np: Pointer to the mii_bus.
274 * Returns a reference to the mii_bus, or NULL if none found. The
275 * embedded struct device will have its reference count incremented,
276 * and this must be put once the bus is finished with.
278 * Because the association of a device_node and mii_bus is made via
279 * of_mdiobus_register(), the mii_bus cannot be found before it is
280 * registered with of_mdiobus_register().
283 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
290 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
293 return d ? to_mii_bus(d) : NULL;
295 EXPORT_SYMBOL(of_mdio_find_bus);
297 /* Walk the list of subnodes of a mdio bus and look for a node that
298 * matches the mdio device's address with its 'reg' property. If
299 * found, set the of_node pointer for the mdio device. This allows
300 * auto-probed phy devices to be supplied with information passed in
303 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
304 struct mdio_device *mdiodev)
306 struct device *dev = &mdiodev->dev;
307 struct device_node *child;
309 if (dev->of_node || !bus->dev.of_node)
312 for_each_available_child_of_node(bus->dev.of_node, child) {
315 addr = of_mdio_parse_addr(dev, child);
319 if (addr == mdiodev->addr) {
320 dev->of_node = child;
321 dev->fwnode = of_fwnode_handle(child);
326 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
327 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
328 struct mdio_device *mdiodev)
334 * mdiobus_create_device_from_board_info - create a full MDIO device given
335 * a mdio_board_info structure
336 * @bus: MDIO bus to create the devices on
337 * @bi: mdio_board_info structure describing the devices
339 * Returns 0 on success or < 0 on error.
341 static int mdiobus_create_device(struct mii_bus *bus,
342 struct mdio_board_info *bi)
344 struct mdio_device *mdiodev;
347 mdiodev = mdio_device_create(bus, bi->mdio_addr);
351 strncpy(mdiodev->modalias, bi->modalias,
352 sizeof(mdiodev->modalias));
353 mdiodev->bus_match = mdio_device_bus_match;
354 mdiodev->dev.platform_data = (void *)bi->platform_data;
356 ret = mdio_device_register(mdiodev);
358 mdio_device_free(mdiodev);
364 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
365 * @bus: target mii_bus
366 * @owner: module containing bus accessor functions
368 * Description: Called by a bus driver to bring up all the PHYs
369 * on a given bus, and attach them to the bus. Drivers should use
370 * mdiobus_register() rather than __mdiobus_register() unless they
371 * need to pass a specific owner module. MDIO devices which are not
372 * PHYs will not be brought up by this function. They are expected to
373 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
375 * Returns 0 on success or < 0 on error.
377 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
379 struct mdio_device *mdiodev;
381 struct gpio_desc *gpiod;
383 if (NULL == bus || NULL == bus->name ||
384 NULL == bus->read || NULL == bus->write)
387 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
388 bus->state != MDIOBUS_UNREGISTERED);
391 bus->dev.parent = bus->parent;
392 bus->dev.class = &mdio_bus_class;
393 bus->dev.groups = NULL;
394 dev_set_name(&bus->dev, "%s", bus->id);
396 err = device_register(&bus->dev);
398 pr_err("mii_bus %s failed to register\n", bus->id);
402 mutex_init(&bus->mdio_lock);
404 /* de-assert bus level PHY GPIO reset */
405 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
407 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
409 device_del(&bus->dev);
410 return PTR_ERR(gpiod);
412 bus->reset_gpiod = gpiod;
414 gpiod_set_value_cansleep(gpiod, 1);
415 udelay(bus->reset_delay_us);
416 gpiod_set_value_cansleep(gpiod, 0);
422 for (i = 0; i < PHY_MAX_ADDR; i++) {
423 if ((bus->phy_mask & (1 << i)) == 0) {
424 struct phy_device *phydev;
426 phydev = mdiobus_scan(bus, i);
427 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
428 err = PTR_ERR(phydev);
434 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
436 bus->state = MDIOBUS_REGISTERED;
437 pr_info("%s: probed\n", bus->name);
442 mdiodev = bus->mdio_map[i];
446 mdiodev->device_remove(mdiodev);
447 mdiodev->device_free(mdiodev);
450 /* Put PHYs in RESET to save power */
451 if (bus->reset_gpiod)
452 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
454 device_del(&bus->dev);
457 EXPORT_SYMBOL(__mdiobus_register);
459 void mdiobus_unregister(struct mii_bus *bus)
461 struct mdio_device *mdiodev;
464 BUG_ON(bus->state != MDIOBUS_REGISTERED);
465 bus->state = MDIOBUS_UNREGISTERED;
467 for (i = 0; i < PHY_MAX_ADDR; i++) {
468 mdiodev = bus->mdio_map[i];
472 if (mdiodev->reset_gpio)
473 gpiod_put(mdiodev->reset_gpio);
475 mdiodev->device_remove(mdiodev);
476 mdiodev->device_free(mdiodev);
479 /* Put PHYs in RESET to save power */
480 if (bus->reset_gpiod)
481 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
483 device_del(&bus->dev);
485 EXPORT_SYMBOL(mdiobus_unregister);
488 * mdiobus_free - free a struct mii_bus
489 * @bus: mii_bus to free
491 * This function releases the reference to the underlying device
492 * object in the mii_bus. If this is the last reference, the mii_bus
495 void mdiobus_free(struct mii_bus *bus)
497 /* For compatibility with error handling in drivers. */
498 if (bus->state == MDIOBUS_ALLOCATED) {
503 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
504 bus->state = MDIOBUS_RELEASED;
506 put_device(&bus->dev);
508 EXPORT_SYMBOL(mdiobus_free);
511 * mdiobus_scan - scan a bus for MDIO devices.
512 * @bus: mii_bus to scan
513 * @addr: address on bus to scan
515 * This function scans the MDIO bus, looking for devices which can be
516 * identified using a vendor/product ID in registers 2 and 3. Not all
517 * MDIO devices have such registers, but PHY devices typically
518 * do. Hence this function assumes anything found is a PHY, or can be
519 * treated as a PHY. Other MDIO devices, such as switches, will
520 * probably not be found during the scan.
522 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
524 struct phy_device *phydev;
527 phydev = get_phy_device(bus, addr, false);
532 * For DT, see if the auto-probed phy has a correspoding child
533 * in the bus node, and set the of_node pointer in this case.
535 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
537 err = phy_device_register(phydev);
539 phy_device_free(phydev);
540 return ERR_PTR(-ENODEV);
545 EXPORT_SYMBOL(mdiobus_scan);
548 * __mdiobus_read - Unlocked version of the mdiobus_read function
549 * @bus: the mii_bus struct
550 * @addr: the phy address
551 * @regnum: register number to read
553 * Read a MDIO bus register. Caller must hold the mdio bus lock.
555 * NOTE: MUST NOT be called from interrupt context.
557 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
561 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
563 retval = bus->read(bus, addr, regnum);
565 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
569 EXPORT_SYMBOL(__mdiobus_read);
572 * __mdiobus_write - Unlocked version of the mdiobus_write function
573 * @bus: the mii_bus struct
574 * @addr: the phy address
575 * @regnum: register number to write
576 * @val: value to write to @regnum
578 * Write a MDIO bus register. Caller must hold the mdio bus lock.
580 * NOTE: MUST NOT be called from interrupt context.
582 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
586 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
588 err = bus->write(bus, addr, regnum, val);
590 trace_mdio_access(bus, 0, addr, regnum, val, err);
594 EXPORT_SYMBOL(__mdiobus_write);
597 * mdiobus_read_nested - Nested version of the mdiobus_read function
598 * @bus: the mii_bus struct
599 * @addr: the phy address
600 * @regnum: register number to read
602 * In case of nested MDIO bus access avoid lockdep false positives by
603 * using mutex_lock_nested().
605 * NOTE: MUST NOT be called from interrupt context,
606 * because the bus read/write functions may wait for an interrupt
607 * to conclude the operation.
609 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
613 BUG_ON(in_interrupt());
615 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
616 retval = __mdiobus_read(bus, addr, regnum);
617 mutex_unlock(&bus->mdio_lock);
621 EXPORT_SYMBOL(mdiobus_read_nested);
624 * mdiobus_read - Convenience function for reading a given MII mgmt register
625 * @bus: the mii_bus struct
626 * @addr: the phy address
627 * @regnum: register number to read
629 * NOTE: MUST NOT be called from interrupt context,
630 * because the bus read/write functions may wait for an interrupt
631 * to conclude the operation.
633 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
637 BUG_ON(in_interrupt());
639 mutex_lock(&bus->mdio_lock);
640 retval = __mdiobus_read(bus, addr, regnum);
641 mutex_unlock(&bus->mdio_lock);
645 EXPORT_SYMBOL(mdiobus_read);
648 * mdiobus_write_nested - Nested version of the mdiobus_write function
649 * @bus: the mii_bus struct
650 * @addr: the phy address
651 * @regnum: register number to write
652 * @val: value to write to @regnum
654 * In case of nested MDIO bus access avoid lockdep false positives by
655 * using mutex_lock_nested().
657 * NOTE: MUST NOT be called from interrupt context,
658 * because the bus read/write functions may wait for an interrupt
659 * to conclude the operation.
661 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
665 BUG_ON(in_interrupt());
667 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
668 err = __mdiobus_write(bus, addr, regnum, val);
669 mutex_unlock(&bus->mdio_lock);
673 EXPORT_SYMBOL(mdiobus_write_nested);
676 * mdiobus_write - Convenience function for writing a given MII mgmt register
677 * @bus: the mii_bus struct
678 * @addr: the phy address
679 * @regnum: register number to write
680 * @val: value to write to @regnum
682 * NOTE: MUST NOT be called from interrupt context,
683 * because the bus read/write functions may wait for an interrupt
684 * to conclude the operation.
686 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
690 BUG_ON(in_interrupt());
692 mutex_lock(&bus->mdio_lock);
693 err = __mdiobus_write(bus, addr, regnum, val);
694 mutex_unlock(&bus->mdio_lock);
698 EXPORT_SYMBOL(mdiobus_write);
701 * mdio_bus_match - determine if given MDIO driver supports the given
703 * @dev: target MDIO device
704 * @drv: given MDIO driver
706 * Description: Given a MDIO device, and a MDIO driver, return 1 if
707 * the driver supports the device. Otherwise, return 0. This may
708 * require calling the devices own match function, since different classes
709 * of MDIO devices have different match criteria.
711 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
713 struct mdio_device *mdio = to_mdio_device(dev);
715 if (of_driver_match_device(dev, drv))
719 return mdio->bus_match(dev, drv);
724 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
728 /* Some devices have extra OF data and an OF-style MODALIAS */
729 rc = of_device_uevent_modalias(dev, env);
736 struct bus_type mdio_bus_type = {
738 .match = mdio_bus_match,
739 .uevent = mdio_uevent,
741 EXPORT_SYMBOL(mdio_bus_type);
743 int __init mdio_bus_init(void)
747 ret = class_register(&mdio_bus_class);
749 ret = bus_register(&mdio_bus_type);
751 class_unregister(&mdio_bus_class);
756 EXPORT_SYMBOL_GPL(mdio_bus_init);
758 #if IS_ENABLED(CONFIG_PHYLIB)
759 void mdio_bus_exit(void)
761 class_unregister(&mdio_bus_class);
762 bus_unregister(&mdio_bus_type);
764 EXPORT_SYMBOL_GPL(mdio_bus_exit);
766 module_init(mdio_bus_init);
767 /* no module_exit, intentional */
768 MODULE_LICENSE("GPL");
769 MODULE_DESCRIPTION("MDIO bus/device layer");