5 * Copyright (c) 2004 Freescale Semiconductor, Inc.
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.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/gpio.h>
26 #include <linux/gpio/consumer.h>
27 #include <linux/of_device.h>
28 #include <linux/of_mdio.h>
29 #include <linux/of_gpio.h>
30 #include <linux/netdevice.h>
31 #include <linux/etherdevice.h>
32 #include <linux/skbuff.h>
33 #include <linux/spinlock.h>
35 #include <linux/module.h>
36 #include <linux/mii.h>
37 #include <linux/ethtool.h>
38 #include <linux/phy.h>
40 #include <linux/uaccess.h>
44 #define CREATE_TRACE_POINTS
45 #include <trace/events/mdio.h>
47 #include "mdio-boardinfo.h"
49 int mdiobus_register_device(struct mdio_device *mdiodev)
51 if (mdiodev->bus->mdio_map[mdiodev->addr])
54 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
58 EXPORT_SYMBOL(mdiobus_register_device);
60 int mdiobus_unregister_device(struct mdio_device *mdiodev)
62 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
65 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
69 EXPORT_SYMBOL(mdiobus_unregister_device);
71 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
73 struct mdio_device *mdiodev;
75 if (addr < 0 || addr >= ARRAY_SIZE(bus->mdio_map))
78 mdiodev = bus->mdio_map[addr];
83 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
86 return container_of(mdiodev, struct phy_device, mdio);
88 EXPORT_SYMBOL(mdiobus_get_phy);
90 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
92 return bus->mdio_map[addr];
94 EXPORT_SYMBOL(mdiobus_is_registered_device);
97 * mdiobus_alloc_size - allocate a mii_bus structure
98 * @size: extra amount of memory to allocate for private storage.
99 * If non-zero, then bus->priv is points to that memory.
101 * Description: called by a bus driver to allocate an mii_bus
102 * structure to fill in.
104 struct mii_bus *mdiobus_alloc_size(size_t size)
107 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
111 /* If we alloc extra space, it should be aligned */
113 alloc_size = aligned_size + size;
115 alloc_size = sizeof(*bus);
117 bus = kzalloc(alloc_size, GFP_KERNEL);
121 bus->state = MDIOBUS_ALLOCATED;
123 bus->priv = (void *)bus + aligned_size;
125 /* Initialise the interrupts to polling */
126 for (i = 0; i < PHY_MAX_ADDR; i++)
127 bus->irq[i] = PHY_POLL;
131 EXPORT_SYMBOL(mdiobus_alloc_size);
133 static void _devm_mdiobus_free(struct device *dev, void *res)
135 mdiobus_free(*(struct mii_bus **)res);
138 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
140 struct mii_bus **r = res;
142 if (WARN_ON(!r || !*r))
149 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
150 * @dev: Device to allocate mii_bus for
151 * @sizeof_priv: Space to allocate for private structure.
153 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
154 * automatically freed on driver detach.
156 * If an mii_bus allocated with this function needs to be freed separately,
157 * devm_mdiobus_free() must be used.
160 * Pointer to allocated mii_bus on success, NULL on failure.
162 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
164 struct mii_bus **ptr, *bus;
166 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
170 /* use raw alloc_dr for kmalloc caller tracing */
171 bus = mdiobus_alloc_size(sizeof_priv);
174 devres_add(dev, ptr);
181 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
184 * devm_mdiobus_free - Resource-managed mdiobus_free()
185 * @dev: Device this mii_bus belongs to
186 * @bus: the mii_bus associated with the device
188 * Free mii_bus allocated with devm_mdiobus_alloc_size().
190 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
194 rc = devres_release(dev, _devm_mdiobus_free,
195 devm_mdiobus_match, bus);
198 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
201 * mdiobus_release - mii_bus device release callback
202 * @d: the target struct device that contains the mii_bus
204 * Description: called when the last reference to an mii_bus is
205 * dropped, to free the underlying memory.
207 static void mdiobus_release(struct device *d)
209 struct mii_bus *bus = to_mii_bus(d);
210 BUG_ON(bus->state != MDIOBUS_RELEASED &&
211 /* for compatibility with error handling in drivers */
212 bus->state != MDIOBUS_ALLOCATED);
216 static struct class mdio_bus_class = {
218 .dev_release = mdiobus_release,
221 #if IS_ENABLED(CONFIG_OF_MDIO)
222 /* Helper function for of_mdio_find_bus */
223 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
225 return dev->of_node == mdio_bus_np;
228 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
229 * @mdio_bus_np: Pointer to the mii_bus.
231 * Returns a reference to the mii_bus, or NULL if none found. The
232 * embedded struct device will have its reference count incremented,
233 * and this must be put once the bus is finished with.
235 * Because the association of a device_node and mii_bus is made via
236 * of_mdiobus_register(), the mii_bus cannot be found before it is
237 * registered with of_mdiobus_register().
240 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
247 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
250 return d ? to_mii_bus(d) : NULL;
252 EXPORT_SYMBOL(of_mdio_find_bus);
254 /* Walk the list of subnodes of a mdio bus and look for a node that
255 * matches the mdio device's address with its 'reg' property. If
256 * found, set the of_node pointer for the mdio device. This allows
257 * auto-probed phy devices to be supplied with information passed in
260 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
261 struct mdio_device *mdiodev)
263 struct device *dev = &mdiodev->dev;
264 struct device_node *child;
266 if (dev->of_node || !bus->dev.of_node)
269 for_each_available_child_of_node(bus->dev.of_node, child) {
272 addr = of_mdio_parse_addr(dev, child);
276 if (addr == mdiodev->addr) {
277 dev->of_node = child;
282 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
283 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
284 struct mdio_device *mdiodev)
290 * mdiobus_create_device_from_board_info - create a full MDIO device given
291 * a mdio_board_info structure
292 * @bus: MDIO bus to create the devices on
293 * @bi: mdio_board_info structure describing the devices
295 * Returns 0 on success or < 0 on error.
297 static int mdiobus_create_device(struct mii_bus *bus,
298 struct mdio_board_info *bi)
300 struct mdio_device *mdiodev;
303 mdiodev = mdio_device_create(bus, bi->mdio_addr);
307 strncpy(mdiodev->modalias, bi->modalias,
308 sizeof(mdiodev->modalias));
309 mdiodev->bus_match = mdio_device_bus_match;
310 mdiodev->dev.platform_data = (void *)bi->platform_data;
312 ret = mdio_device_register(mdiodev);
314 mdio_device_free(mdiodev);
320 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
321 * @bus: target mii_bus
322 * @owner: module containing bus accessor functions
324 * Description: Called by a bus driver to bring up all the PHYs
325 * on a given bus, and attach them to the bus. Drivers should use
326 * mdiobus_register() rather than __mdiobus_register() unless they
327 * need to pass a specific owner module. MDIO devices which are not
328 * PHYs will not be brought up by this function. They are expected to
329 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
331 * Returns 0 on success or < 0 on error.
333 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
335 struct mdio_device *mdiodev;
337 struct gpio_desc *gpiod;
339 if (NULL == bus || NULL == bus->name ||
340 NULL == bus->read || NULL == bus->write)
343 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
344 bus->state != MDIOBUS_UNREGISTERED);
347 bus->dev.parent = bus->parent;
348 bus->dev.class = &mdio_bus_class;
349 bus->dev.groups = NULL;
350 dev_set_name(&bus->dev, "%s", bus->id);
352 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
353 * the device in mdiobus_free()
355 * State will be updated later in this function in case of success
357 bus->state = MDIOBUS_UNREGISTERED;
359 err = device_register(&bus->dev);
361 pr_err("mii_bus %s failed to register\n", bus->id);
365 mutex_init(&bus->mdio_lock);
367 /* de-assert bus level PHY GPIO reset */
368 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
370 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
372 device_del(&bus->dev);
373 return PTR_ERR(gpiod);
375 bus->reset_gpiod = gpiod;
377 gpiod_set_value_cansleep(gpiod, 1);
378 udelay(bus->reset_delay_us);
379 gpiod_set_value_cansleep(gpiod, 0);
385 for (i = 0; i < PHY_MAX_ADDR; i++) {
386 if ((bus->phy_mask & BIT(i)) == 0) {
387 struct phy_device *phydev;
389 phydev = mdiobus_scan(bus, i);
390 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
391 err = PTR_ERR(phydev);
397 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
399 bus->state = MDIOBUS_REGISTERED;
400 dev_dbg(&bus->dev, "probed\n");
405 mdiodev = bus->mdio_map[i];
409 mdiodev->device_remove(mdiodev);
410 mdiodev->device_free(mdiodev);
413 /* Put PHYs in RESET to save power */
414 if (bus->reset_gpiod)
415 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
417 device_del(&bus->dev);
420 EXPORT_SYMBOL(__mdiobus_register);
422 void mdiobus_unregister(struct mii_bus *bus)
424 struct mdio_device *mdiodev;
427 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
429 bus->state = MDIOBUS_UNREGISTERED;
431 for (i = 0; i < PHY_MAX_ADDR; i++) {
432 mdiodev = bus->mdio_map[i];
436 mdiodev->device_remove(mdiodev);
437 mdiodev->device_free(mdiodev);
440 /* Put PHYs in RESET to save power */
441 if (bus->reset_gpiod)
442 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
444 device_del(&bus->dev);
446 EXPORT_SYMBOL(mdiobus_unregister);
449 * mdiobus_free - free a struct mii_bus
450 * @bus: mii_bus to free
452 * This function releases the reference to the underlying device
453 * object in the mii_bus. If this is the last reference, the mii_bus
456 void mdiobus_free(struct mii_bus *bus)
458 /* For compatibility with error handling in drivers. */
459 if (bus->state == MDIOBUS_ALLOCATED) {
464 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
465 bus->state = MDIOBUS_RELEASED;
467 put_device(&bus->dev);
469 EXPORT_SYMBOL(mdiobus_free);
472 * mdiobus_scan - scan a bus for MDIO devices.
473 * @bus: mii_bus to scan
474 * @addr: address on bus to scan
476 * This function scans the MDIO bus, looking for devices which can be
477 * identified using a vendor/product ID in registers 2 and 3. Not all
478 * MDIO devices have such registers, but PHY devices typically
479 * do. Hence this function assumes anything found is a PHY, or can be
480 * treated as a PHY. Other MDIO devices, such as switches, will
481 * probably not be found during the scan.
483 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
485 struct phy_device *phydev;
488 phydev = get_phy_device(bus, addr, false);
493 * For DT, see if the auto-probed phy has a correspoding child
494 * in the bus node, and set the of_node pointer in this case.
496 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
498 err = phy_device_register(phydev);
500 phy_device_free(phydev);
501 return ERR_PTR(-ENODEV);
506 EXPORT_SYMBOL(mdiobus_scan);
509 * mdiobus_read_nested - Nested version of the mdiobus_read function
510 * @bus: the mii_bus struct
511 * @addr: the phy address
512 * @regnum: register number to read
514 * In case of nested MDIO bus access avoid lockdep false positives by
515 * using mutex_lock_nested().
517 * NOTE: MUST NOT be called from interrupt context,
518 * because the bus read/write functions may wait for an interrupt
519 * to conclude the operation.
521 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
525 BUG_ON(in_interrupt());
527 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
528 retval = bus->read(bus, addr, regnum);
529 mutex_unlock(&bus->mdio_lock);
531 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
535 EXPORT_SYMBOL(mdiobus_read_nested);
538 * mdiobus_read - Convenience function for reading a given MII mgmt register
539 * @bus: the mii_bus struct
540 * @addr: the phy address
541 * @regnum: register number to read
543 * NOTE: MUST NOT be called from interrupt context,
544 * because the bus read/write functions may wait for an interrupt
545 * to conclude the operation.
547 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
551 BUG_ON(in_interrupt());
553 mutex_lock(&bus->mdio_lock);
554 retval = bus->read(bus, addr, regnum);
555 mutex_unlock(&bus->mdio_lock);
557 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
561 EXPORT_SYMBOL(mdiobus_read);
564 * mdiobus_write_nested - Nested 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 * In case of nested MDIO bus access avoid lockdep false positives by
571 * using mutex_lock_nested().
573 * NOTE: MUST NOT be called from interrupt context,
574 * because the bus read/write functions may wait for an interrupt
575 * to conclude the operation.
577 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
581 BUG_ON(in_interrupt());
583 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
584 err = bus->write(bus, addr, regnum, val);
585 mutex_unlock(&bus->mdio_lock);
587 trace_mdio_access(bus, 0, addr, regnum, val, err);
591 EXPORT_SYMBOL(mdiobus_write_nested);
594 * mdiobus_write - Convenience function for writing a given MII mgmt register
595 * @bus: the mii_bus struct
596 * @addr: the phy address
597 * @regnum: register number to write
598 * @val: value to write to @regnum
600 * NOTE: MUST NOT be called from interrupt context,
601 * because the bus read/write functions may wait for an interrupt
602 * to conclude the operation.
604 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
608 BUG_ON(in_interrupt());
610 mutex_lock(&bus->mdio_lock);
611 err = bus->write(bus, addr, regnum, val);
612 mutex_unlock(&bus->mdio_lock);
614 trace_mdio_access(bus, 0, addr, regnum, val, err);
618 EXPORT_SYMBOL(mdiobus_write);
621 * mdio_bus_match - determine if given MDIO driver supports the given
623 * @dev: target MDIO device
624 * @drv: given MDIO driver
626 * Description: Given a MDIO device, and a MDIO driver, return 1 if
627 * the driver supports the device. Otherwise, return 0. This may
628 * require calling the devices own match function, since different classes
629 * of MDIO devices have different match criteria.
631 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
633 struct mdio_device *mdio = to_mdio_device(dev);
635 if (of_driver_match_device(dev, drv))
639 return mdio->bus_match(dev, drv);
644 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
648 /* Some devices have extra OF data and an OF-style MODALIAS */
649 rc = of_device_uevent_modalias(dev, env);
657 static int mdio_bus_suspend(struct device *dev)
659 struct mdio_device *mdio = to_mdio_device(dev);
661 if (mdio->pm_ops && mdio->pm_ops->suspend)
662 return mdio->pm_ops->suspend(dev);
667 static int mdio_bus_resume(struct device *dev)
669 struct mdio_device *mdio = to_mdio_device(dev);
671 if (mdio->pm_ops && mdio->pm_ops->resume)
672 return mdio->pm_ops->resume(dev);
677 static int mdio_bus_restore(struct device *dev)
679 struct mdio_device *mdio = to_mdio_device(dev);
681 if (mdio->pm_ops && mdio->pm_ops->restore)
682 return mdio->pm_ops->restore(dev);
687 static const struct dev_pm_ops mdio_bus_pm_ops = {
688 .suspend = mdio_bus_suspend,
689 .resume = mdio_bus_resume,
690 .freeze = mdio_bus_suspend,
691 .thaw = mdio_bus_resume,
692 .restore = mdio_bus_restore,
695 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
699 #define MDIO_BUS_PM_OPS NULL
701 #endif /* CONFIG_PM */
703 struct bus_type mdio_bus_type = {
705 .match = mdio_bus_match,
706 .uevent = mdio_uevent,
707 .pm = MDIO_BUS_PM_OPS,
709 EXPORT_SYMBOL(mdio_bus_type);
711 int __init mdio_bus_init(void)
715 ret = class_register(&mdio_bus_class);
717 ret = bus_register(&mdio_bus_type);
719 class_unregister(&mdio_bus_class);
725 #if IS_ENABLED(CONFIG_PHYLIB)
726 void mdio_bus_exit(void)
728 class_unregister(&mdio_bus_class);
729 bus_unregister(&mdio_bus_type);
731 EXPORT_SYMBOL_GPL(mdio_bus_exit);
733 module_init(mdio_bus_init);
734 /* no module_exit, intentional */
735 MODULE_LICENSE("GPL");
736 MODULE_DESCRIPTION("MDIO bus/device layer");