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 = bus->mdio_map[addr];
78 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
81 return container_of(mdiodev, struct phy_device, mdio);
83 EXPORT_SYMBOL(mdiobus_get_phy);
85 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
87 return bus->mdio_map[addr];
89 EXPORT_SYMBOL(mdiobus_is_registered_device);
92 * mdiobus_alloc_size - allocate a mii_bus structure
93 * @size: extra amount of memory to allocate for private storage.
94 * If non-zero, then bus->priv is points to that memory.
96 * Description: called by a bus driver to allocate an mii_bus
97 * structure to fill in.
99 struct mii_bus *mdiobus_alloc_size(size_t size)
102 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
106 /* If we alloc extra space, it should be aligned */
108 alloc_size = aligned_size + size;
110 alloc_size = sizeof(*bus);
112 bus = kzalloc(alloc_size, GFP_KERNEL);
116 bus->state = MDIOBUS_ALLOCATED;
118 bus->priv = (void *)bus + aligned_size;
120 /* Initialise the interrupts to polling */
121 for (i = 0; i < PHY_MAX_ADDR; i++)
122 bus->irq[i] = PHY_POLL;
126 EXPORT_SYMBOL(mdiobus_alloc_size);
128 static void _devm_mdiobus_free(struct device *dev, void *res)
130 mdiobus_free(*(struct mii_bus **)res);
133 static int devm_mdiobus_match(struct device *dev, void *res, void *data)
135 struct mii_bus **r = res;
137 if (WARN_ON(!r || !*r))
144 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
145 * @dev: Device to allocate mii_bus for
146 * @sizeof_priv: Space to allocate for private structure.
148 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
149 * automatically freed on driver detach.
151 * If an mii_bus allocated with this function needs to be freed separately,
152 * devm_mdiobus_free() must be used.
155 * Pointer to allocated mii_bus on success, NULL on failure.
157 struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
159 struct mii_bus **ptr, *bus;
161 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
165 /* use raw alloc_dr for kmalloc caller tracing */
166 bus = mdiobus_alloc_size(sizeof_priv);
169 devres_add(dev, ptr);
176 EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
179 * devm_mdiobus_free - Resource-managed mdiobus_free()
180 * @dev: Device this mii_bus belongs to
181 * @bus: the mii_bus associated with the device
183 * Free mii_bus allocated with devm_mdiobus_alloc_size().
185 void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
189 rc = devres_release(dev, _devm_mdiobus_free,
190 devm_mdiobus_match, bus);
193 EXPORT_SYMBOL_GPL(devm_mdiobus_free);
196 * mdiobus_release - mii_bus device release callback
197 * @d: the target struct device that contains the mii_bus
199 * Description: called when the last reference to an mii_bus is
200 * dropped, to free the underlying memory.
202 static void mdiobus_release(struct device *d)
204 struct mii_bus *bus = to_mii_bus(d);
205 BUG_ON(bus->state != MDIOBUS_RELEASED &&
206 /* for compatibility with error handling in drivers */
207 bus->state != MDIOBUS_ALLOCATED);
211 static struct class mdio_bus_class = {
213 .dev_release = mdiobus_release,
216 #if IS_ENABLED(CONFIG_OF_MDIO)
217 /* Helper function for of_mdio_find_bus */
218 static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
220 return dev->of_node == mdio_bus_np;
223 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
224 * @mdio_bus_np: Pointer to the mii_bus.
226 * Returns a reference to the mii_bus, or NULL if none found. The
227 * embedded struct device will have its reference count incremented,
228 * and this must be put once the bus is finished with.
230 * Because the association of a device_node and mii_bus is made via
231 * of_mdiobus_register(), the mii_bus cannot be found before it is
232 * registered with of_mdiobus_register().
235 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
242 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
245 return d ? to_mii_bus(d) : NULL;
247 EXPORT_SYMBOL(of_mdio_find_bus);
249 /* Walk the list of subnodes of a mdio bus and look for a node that
250 * matches the mdio device's address with its 'reg' property. If
251 * found, set the of_node pointer for the mdio device. This allows
252 * auto-probed phy devices to be supplied with information passed in
255 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
256 struct mdio_device *mdiodev)
258 struct device *dev = &mdiodev->dev;
259 struct device_node *child;
261 if (dev->of_node || !bus->dev.of_node)
264 for_each_available_child_of_node(bus->dev.of_node, child) {
267 addr = of_mdio_parse_addr(dev, child);
271 if (addr == mdiodev->addr) {
272 dev->of_node = child;
277 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
278 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
279 struct mdio_device *mdiodev)
285 * mdiobus_create_device_from_board_info - create a full MDIO device given
286 * a mdio_board_info structure
287 * @bus: MDIO bus to create the devices on
288 * @bi: mdio_board_info structure describing the devices
290 * Returns 0 on success or < 0 on error.
292 static int mdiobus_create_device(struct mii_bus *bus,
293 struct mdio_board_info *bi)
295 struct mdio_device *mdiodev;
298 mdiodev = mdio_device_create(bus, bi->mdio_addr);
302 strncpy(mdiodev->modalias, bi->modalias,
303 sizeof(mdiodev->modalias));
304 mdiodev->bus_match = mdio_device_bus_match;
305 mdiodev->dev.platform_data = (void *)bi->platform_data;
307 ret = mdio_device_register(mdiodev);
309 mdio_device_free(mdiodev);
315 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
316 * @bus: target mii_bus
317 * @owner: module containing bus accessor functions
319 * Description: Called by a bus driver to bring up all the PHYs
320 * on a given bus, and attach them to the bus. Drivers should use
321 * mdiobus_register() rather than __mdiobus_register() unless they
322 * need to pass a specific owner module. MDIO devices which are not
323 * PHYs will not be brought up by this function. They are expected to
324 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
326 * Returns 0 on success or < 0 on error.
328 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
330 struct mdio_device *mdiodev;
332 struct gpio_desc *gpiod;
334 if (NULL == bus || NULL == bus->name ||
335 NULL == bus->read || NULL == bus->write)
338 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
339 bus->state != MDIOBUS_UNREGISTERED);
342 bus->dev.parent = bus->parent;
343 bus->dev.class = &mdio_bus_class;
344 bus->dev.groups = NULL;
345 dev_set_name(&bus->dev, "%s", bus->id);
347 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
348 * the device in mdiobus_free()
350 * State will be updated later in this function in case of success
352 bus->state = MDIOBUS_UNREGISTERED;
354 err = device_register(&bus->dev);
356 pr_err("mii_bus %s failed to register\n", bus->id);
357 put_device(&bus->dev);
361 mutex_init(&bus->mdio_lock);
363 /* de-assert bus level PHY GPIO reset */
364 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
366 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
368 device_del(&bus->dev);
369 return PTR_ERR(gpiod);
371 bus->reset_gpiod = gpiod;
373 gpiod_set_value_cansleep(gpiod, 1);
374 udelay(bus->reset_delay_us);
375 gpiod_set_value_cansleep(gpiod, 0);
381 for (i = 0; i < PHY_MAX_ADDR; i++) {
382 if ((bus->phy_mask & (1 << i)) == 0) {
383 struct phy_device *phydev;
385 phydev = mdiobus_scan(bus, i);
386 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
387 err = PTR_ERR(phydev);
393 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
395 bus->state = MDIOBUS_REGISTERED;
396 pr_info("%s: probed\n", bus->name);
401 mdiodev = bus->mdio_map[i];
405 mdiodev->device_remove(mdiodev);
406 mdiodev->device_free(mdiodev);
409 /* Put PHYs in RESET to save power */
410 if (bus->reset_gpiod)
411 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
413 device_del(&bus->dev);
416 EXPORT_SYMBOL(__mdiobus_register);
418 void mdiobus_unregister(struct mii_bus *bus)
420 struct mdio_device *mdiodev;
423 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
425 bus->state = MDIOBUS_UNREGISTERED;
427 for (i = 0; i < PHY_MAX_ADDR; i++) {
428 mdiodev = bus->mdio_map[i];
432 mdiodev->device_remove(mdiodev);
433 mdiodev->device_free(mdiodev);
436 /* Put PHYs in RESET to save power */
437 if (bus->reset_gpiod)
438 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
440 device_del(&bus->dev);
442 EXPORT_SYMBOL(mdiobus_unregister);
445 * mdiobus_free - free a struct mii_bus
446 * @bus: mii_bus to free
448 * This function releases the reference to the underlying device
449 * object in the mii_bus. If this is the last reference, the mii_bus
452 void mdiobus_free(struct mii_bus *bus)
454 /* For compatibility with error handling in drivers. */
455 if (bus->state == MDIOBUS_ALLOCATED) {
460 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
461 bus->state = MDIOBUS_RELEASED;
463 put_device(&bus->dev);
465 EXPORT_SYMBOL(mdiobus_free);
468 * mdiobus_scan - scan a bus for MDIO devices.
469 * @bus: mii_bus to scan
470 * @addr: address on bus to scan
472 * This function scans the MDIO bus, looking for devices which can be
473 * identified using a vendor/product ID in registers 2 and 3. Not all
474 * MDIO devices have such registers, but PHY devices typically
475 * do. Hence this function assumes anything found is a PHY, or can be
476 * treated as a PHY. Other MDIO devices, such as switches, will
477 * probably not be found during the scan.
479 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
481 struct phy_device *phydev;
484 phydev = get_phy_device(bus, addr, false);
489 * For DT, see if the auto-probed phy has a correspoding child
490 * in the bus node, and set the of_node pointer in this case.
492 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
494 err = phy_device_register(phydev);
496 phy_device_free(phydev);
497 return ERR_PTR(-ENODEV);
502 EXPORT_SYMBOL(mdiobus_scan);
505 * mdiobus_read_nested - Nested version of the mdiobus_read function
506 * @bus: the mii_bus struct
507 * @addr: the phy address
508 * @regnum: register number to read
510 * In case of nested MDIO bus access avoid lockdep false positives by
511 * using mutex_lock_nested().
513 * NOTE: MUST NOT be called from interrupt context,
514 * because the bus read/write functions may wait for an interrupt
515 * to conclude the operation.
517 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
521 BUG_ON(in_interrupt());
523 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
524 retval = bus->read(bus, addr, regnum);
525 mutex_unlock(&bus->mdio_lock);
527 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
531 EXPORT_SYMBOL(mdiobus_read_nested);
534 * mdiobus_read - Convenience function for reading a given MII mgmt register
535 * @bus: the mii_bus struct
536 * @addr: the phy address
537 * @regnum: register number to read
539 * NOTE: MUST NOT be called from interrupt context,
540 * because the bus read/write functions may wait for an interrupt
541 * to conclude the operation.
543 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
547 BUG_ON(in_interrupt());
549 mutex_lock(&bus->mdio_lock);
550 retval = bus->read(bus, addr, regnum);
551 mutex_unlock(&bus->mdio_lock);
553 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
557 EXPORT_SYMBOL(mdiobus_read);
560 * mdiobus_write_nested - Nested version of the mdiobus_write function
561 * @bus: the mii_bus struct
562 * @addr: the phy address
563 * @regnum: register number to write
564 * @val: value to write to @regnum
566 * In case of nested MDIO bus access avoid lockdep false positives by
567 * using mutex_lock_nested().
569 * NOTE: MUST NOT be called from interrupt context,
570 * because the bus read/write functions may wait for an interrupt
571 * to conclude the operation.
573 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
577 BUG_ON(in_interrupt());
579 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
580 err = bus->write(bus, addr, regnum, val);
581 mutex_unlock(&bus->mdio_lock);
583 trace_mdio_access(bus, 0, addr, regnum, val, err);
587 EXPORT_SYMBOL(mdiobus_write_nested);
590 * mdiobus_write - Convenience function for writing a given MII mgmt register
591 * @bus: the mii_bus struct
592 * @addr: the phy address
593 * @regnum: register number to write
594 * @val: value to write to @regnum
596 * NOTE: MUST NOT be called from interrupt context,
597 * because the bus read/write functions may wait for an interrupt
598 * to conclude the operation.
600 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
604 BUG_ON(in_interrupt());
606 mutex_lock(&bus->mdio_lock);
607 err = bus->write(bus, addr, regnum, val);
608 mutex_unlock(&bus->mdio_lock);
610 trace_mdio_access(bus, 0, addr, regnum, val, err);
614 EXPORT_SYMBOL(mdiobus_write);
617 * mdio_bus_match - determine if given MDIO driver supports the given
619 * @dev: target MDIO device
620 * @drv: given MDIO driver
622 * Description: Given a MDIO device, and a MDIO driver, return 1 if
623 * the driver supports the device. Otherwise, return 0. This may
624 * require calling the devices own match function, since different classes
625 * of MDIO devices have different match criteria.
627 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
629 struct mdio_device *mdio = to_mdio_device(dev);
631 if (of_driver_match_device(dev, drv))
635 return mdio->bus_match(dev, drv);
640 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
644 /* Some devices have extra OF data and an OF-style MODALIAS */
645 rc = of_device_uevent_modalias(dev, env);
653 static int mdio_bus_suspend(struct device *dev)
655 struct mdio_device *mdio = to_mdio_device(dev);
657 if (mdio->pm_ops && mdio->pm_ops->suspend)
658 return mdio->pm_ops->suspend(dev);
663 static int mdio_bus_resume(struct device *dev)
665 struct mdio_device *mdio = to_mdio_device(dev);
667 if (mdio->pm_ops && mdio->pm_ops->resume)
668 return mdio->pm_ops->resume(dev);
673 static int mdio_bus_restore(struct device *dev)
675 struct mdio_device *mdio = to_mdio_device(dev);
677 if (mdio->pm_ops && mdio->pm_ops->restore)
678 return mdio->pm_ops->restore(dev);
683 static const struct dev_pm_ops mdio_bus_pm_ops = {
684 .suspend = mdio_bus_suspend,
685 .resume = mdio_bus_resume,
686 .freeze = mdio_bus_suspend,
687 .thaw = mdio_bus_resume,
688 .restore = mdio_bus_restore,
691 #define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
695 #define MDIO_BUS_PM_OPS NULL
697 #endif /* CONFIG_PM */
699 struct bus_type mdio_bus_type = {
701 .match = mdio_bus_match,
702 .uevent = mdio_uevent,
703 .pm = MDIO_BUS_PM_OPS,
705 EXPORT_SYMBOL(mdio_bus_type);
707 int __init mdio_bus_init(void)
711 ret = class_register(&mdio_bus_class);
713 ret = bus_register(&mdio_bus_type);
715 class_unregister(&mdio_bus_class);
720 EXPORT_SYMBOL_GPL(mdio_bus_init);
722 #if IS_ENABLED(CONFIG_PHYLIB)
723 void mdio_bus_exit(void)
725 class_unregister(&mdio_bus_class);
726 bus_unregister(&mdio_bus_type);
728 EXPORT_SYMBOL_GPL(mdio_bus_exit);
730 module_init(mdio_bus_init);
731 /* no module_exit, intentional */
732 MODULE_LICENSE("GPL");
733 MODULE_DESCRIPTION("MDIO bus/device layer");