[go: nahoru, domu]
1/* MDIO Bus interface
2 *
3 * Author: Andy Fleming
4 *
5 * Copyright (c) 2004 Freescale Semiconductor, Inc.
6 *
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.
11 *
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
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/of_device.h>
26#include <linux/of_mdio.h>
27#include <linux/netdevice.h>
28#include <linux/etherdevice.h>
29#include <linux/skbuff.h>
30#include <linux/spinlock.h>
31#include <linux/mm.h>
32#include <linux/module.h>
33#include <linux/mii.h>
34#include <linux/ethtool.h>
35#include <linux/phy.h>
36#include <linux/io.h>
37#include <linux/uaccess.h>
38
39#include <asm/irq.h>
40
41/**
42 * mdiobus_alloc_size - allocate a mii_bus structure
43 * @size: extra amount of memory to allocate for private storage.
44 * If non-zero, then bus->priv is points to that memory.
45 *
46 * Description: called by a bus driver to allocate an mii_bus
47 * structure to fill in.
48 */
49struct mii_bus *mdiobus_alloc_size(size_t size)
50{
51	struct mii_bus *bus;
52	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
53	size_t alloc_size;
54
55	/* If we alloc extra space, it should be aligned */
56	if (size)
57		alloc_size = aligned_size + size;
58	else
59		alloc_size = sizeof(*bus);
60
61	bus = kzalloc(alloc_size, GFP_KERNEL);
62	if (bus) {
63		bus->state = MDIOBUS_ALLOCATED;
64		if (size)
65			bus->priv = (void *)bus + aligned_size;
66	}
67
68	return bus;
69}
70EXPORT_SYMBOL(mdiobus_alloc_size);
71
72static void _devm_mdiobus_free(struct device *dev, void *res)
73{
74	mdiobus_free(*(struct mii_bus **)res);
75}
76
77static int devm_mdiobus_match(struct device *dev, void *res, void *data)
78{
79	struct mii_bus **r = res;
80
81	if (WARN_ON(!r || !*r))
82		return 0;
83
84	return *r == data;
85}
86
87/**
88 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
89 * @dev:		Device to allocate mii_bus for
90 * @sizeof_priv:	Space to allocate for private structure.
91 *
92 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
93 * automatically freed on driver detach.
94 *
95 * If an mii_bus allocated with this function needs to be freed separately,
96 * devm_mdiobus_free() must be used.
97 *
98 * RETURNS:
99 * Pointer to allocated mii_bus on success, NULL on failure.
100 */
101struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
102{
103	struct mii_bus **ptr, *bus;
104
105	ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
106	if (!ptr)
107		return NULL;
108
109	/* use raw alloc_dr for kmalloc caller tracing */
110	bus = mdiobus_alloc_size(sizeof_priv);
111	if (bus) {
112		*ptr = bus;
113		devres_add(dev, ptr);
114	} else {
115		devres_free(ptr);
116	}
117
118	return bus;
119}
120EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
121
122/**
123 * devm_mdiobus_free - Resource-managed mdiobus_free()
124 * @dev:		Device this mii_bus belongs to
125 * @bus:		the mii_bus associated with the device
126 *
127 * Free mii_bus allocated with devm_mdiobus_alloc_size().
128 */
129void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
130{
131	int rc;
132
133	rc = devres_release(dev, _devm_mdiobus_free,
134			    devm_mdiobus_match, bus);
135	WARN_ON(rc);
136}
137EXPORT_SYMBOL_GPL(devm_mdiobus_free);
138
139/**
140 * mdiobus_release - mii_bus device release callback
141 * @d: the target struct device that contains the mii_bus
142 *
143 * Description: called when the last reference to an mii_bus is
144 * dropped, to free the underlying memory.
145 */
146static void mdiobus_release(struct device *d)
147{
148	struct mii_bus *bus = to_mii_bus(d);
149	BUG_ON(bus->state != MDIOBUS_RELEASED &&
150	       /* for compatibility with error handling in drivers */
151	       bus->state != MDIOBUS_ALLOCATED);
152	kfree(bus);
153}
154
155static struct class mdio_bus_class = {
156	.name		= "mdio_bus",
157	.dev_release	= mdiobus_release,
158};
159
160#if IS_ENABLED(CONFIG_OF_MDIO)
161/* Helper function for of_mdio_find_bus */
162static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
163{
164	return dev->of_node == mdio_bus_np;
165}
166/**
167 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
168 * @mdio_bus_np: Pointer to the mii_bus.
169 *
170 * Returns a pointer to the mii_bus, or NULL if none found.
171 *
172 * Because the association of a device_node and mii_bus is made via
173 * of_mdiobus_register(), the mii_bus cannot be found before it is
174 * registered with of_mdiobus_register().
175 *
176 */
177struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
178{
179	struct device *d;
180
181	if (!mdio_bus_np)
182		return NULL;
183
184	d = class_find_device(&mdio_bus_class, NULL,  mdio_bus_np,
185			      of_mdio_bus_match);
186
187	return d ? to_mii_bus(d) : NULL;
188}
189EXPORT_SYMBOL(of_mdio_find_bus);
190
191/* Walk the list of subnodes of a mdio bus and look for a node that matches the
192 * phy's address with its 'reg' property. If found, set the of_node pointer for
193 * the phy. This allows auto-probed pyh devices to be supplied with information
194 * passed in via DT.
195 */
196static void of_mdiobus_link_phydev(struct mii_bus *mdio,
197				   struct phy_device *phydev)
198{
199	struct device *dev = &phydev->dev;
200	struct device_node *child;
201
202	if (dev->of_node || !mdio->dev.of_node)
203		return;
204
205	for_each_available_child_of_node(mdio->dev.of_node, child) {
206		int addr;
207		int ret;
208
209		ret = of_property_read_u32(child, "reg", &addr);
210		if (ret < 0) {
211			dev_err(dev, "%s has invalid PHY address\n",
212				child->full_name);
213			continue;
214		}
215
216		/* A PHY must have a reg property in the range [0-31] */
217		if (addr >= PHY_MAX_ADDR) {
218			dev_err(dev, "%s PHY address %i is too large\n",
219				child->full_name, addr);
220			continue;
221		}
222
223		if (addr == phydev->addr) {
224			dev->of_node = child;
225			return;
226		}
227	}
228}
229#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
230static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
231					  struct phy_device *phydev)
232{
233}
234#endif
235
236/**
237 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
238 * @bus: target mii_bus
239 *
240 * Description: Called by a bus driver to bring up all the PHYs
241 *   on a given bus, and attach them to the bus.
242 *
243 * Returns 0 on success or < 0 on error.
244 */
245int mdiobus_register(struct mii_bus *bus)
246{
247	int i, err;
248
249	if (NULL == bus || NULL == bus->name ||
250	    NULL == bus->read || NULL == bus->write)
251		return -EINVAL;
252
253	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
254	       bus->state != MDIOBUS_UNREGISTERED);
255
256	bus->dev.parent = bus->parent;
257	bus->dev.class = &mdio_bus_class;
258	bus->dev.groups = NULL;
259	dev_set_name(&bus->dev, "%s", bus->id);
260
261	err = device_register(&bus->dev);
262	if (err) {
263		pr_err("mii_bus %s failed to register\n", bus->id);
264		put_device(&bus->dev);
265		return -EINVAL;
266	}
267
268	mutex_init(&bus->mdio_lock);
269
270	if (bus->reset)
271		bus->reset(bus);
272
273	for (i = 0; i < PHY_MAX_ADDR; i++) {
274		if ((bus->phy_mask & (1 << i)) == 0) {
275			struct phy_device *phydev;
276
277			phydev = mdiobus_scan(bus, i);
278			if (IS_ERR(phydev)) {
279				err = PTR_ERR(phydev);
280				goto error;
281			}
282		}
283	}
284
285	bus->state = MDIOBUS_REGISTERED;
286	pr_info("%s: probed\n", bus->name);
287	return 0;
288
289error:
290	while (--i >= 0) {
291		if (bus->phy_map[i])
292			device_unregister(&bus->phy_map[i]->dev);
293	}
294	device_del(&bus->dev);
295	return err;
296}
297EXPORT_SYMBOL(mdiobus_register);
298
299void mdiobus_unregister(struct mii_bus *bus)
300{
301	int i;
302
303	BUG_ON(bus->state != MDIOBUS_REGISTERED);
304	bus->state = MDIOBUS_UNREGISTERED;
305
306	device_del(&bus->dev);
307	for (i = 0; i < PHY_MAX_ADDR; i++) {
308		if (bus->phy_map[i])
309			device_unregister(&bus->phy_map[i]->dev);
310		bus->phy_map[i] = NULL;
311	}
312}
313EXPORT_SYMBOL(mdiobus_unregister);
314
315/**
316 * mdiobus_free - free a struct mii_bus
317 * @bus: mii_bus to free
318 *
319 * This function releases the reference to the underlying device
320 * object in the mii_bus.  If this is the last reference, the mii_bus
321 * will be freed.
322 */
323void mdiobus_free(struct mii_bus *bus)
324{
325	/* For compatibility with error handling in drivers. */
326	if (bus->state == MDIOBUS_ALLOCATED) {
327		kfree(bus);
328		return;
329	}
330
331	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
332	bus->state = MDIOBUS_RELEASED;
333
334	put_device(&bus->dev);
335}
336EXPORT_SYMBOL(mdiobus_free);
337
338struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
339{
340	struct phy_device *phydev;
341	int err;
342
343	phydev = get_phy_device(bus, addr, false);
344	if (IS_ERR(phydev) || phydev == NULL)
345		return phydev;
346
347	/*
348	 * For DT, see if the auto-probed phy has a correspoding child
349	 * in the bus node, and set the of_node pointer in this case.
350	 */
351	of_mdiobus_link_phydev(bus, phydev);
352
353	err = phy_device_register(phydev);
354	if (err) {
355		phy_device_free(phydev);
356		return NULL;
357	}
358
359	return phydev;
360}
361EXPORT_SYMBOL(mdiobus_scan);
362
363/**
364 * mdiobus_read - Convenience function for reading a given MII mgmt register
365 * @bus: the mii_bus struct
366 * @addr: the phy address
367 * @regnum: register number to read
368 *
369 * NOTE: MUST NOT be called from interrupt context,
370 * because the bus read/write functions may wait for an interrupt
371 * to conclude the operation.
372 */
373int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
374{
375	int retval;
376
377	BUG_ON(in_interrupt());
378
379	mutex_lock(&bus->mdio_lock);
380	retval = bus->read(bus, addr, regnum);
381	mutex_unlock(&bus->mdio_lock);
382
383	return retval;
384}
385EXPORT_SYMBOL(mdiobus_read);
386
387/**
388 * mdiobus_write - Convenience function for writing a given MII mgmt register
389 * @bus: the mii_bus struct
390 * @addr: the phy address
391 * @regnum: register number to write
392 * @val: value to write to @regnum
393 *
394 * NOTE: MUST NOT be called from interrupt context,
395 * because the bus read/write functions may wait for an interrupt
396 * to conclude the operation.
397 */
398int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
399{
400	int err;
401
402	BUG_ON(in_interrupt());
403
404	mutex_lock(&bus->mdio_lock);
405	err = bus->write(bus, addr, regnum, val);
406	mutex_unlock(&bus->mdio_lock);
407
408	return err;
409}
410EXPORT_SYMBOL(mdiobus_write);
411
412/**
413 * mdio_bus_match - determine if given PHY driver supports the given PHY device
414 * @dev: target PHY device
415 * @drv: given PHY driver
416 *
417 * Description: Given a PHY device, and a PHY driver, return 1 if
418 *   the driver supports the device.  Otherwise, return 0.
419 */
420static int mdio_bus_match(struct device *dev, struct device_driver *drv)
421{
422	struct phy_device *phydev = to_phy_device(dev);
423	struct phy_driver *phydrv = to_phy_driver(drv);
424
425	if (of_driver_match_device(dev, drv))
426		return 1;
427
428	if (phydrv->match_phy_device)
429		return phydrv->match_phy_device(phydev);
430
431	return (phydrv->phy_id & phydrv->phy_id_mask) ==
432		(phydev->phy_id & phydrv->phy_id_mask);
433}
434
435#ifdef CONFIG_PM
436
437static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
438{
439	struct device_driver *drv = phydev->dev.driver;
440	struct phy_driver *phydrv = to_phy_driver(drv);
441	struct net_device *netdev = phydev->attached_dev;
442
443	if (!drv || !phydrv->suspend)
444		return false;
445
446	/* PHY not attached? May suspend. */
447	if (!netdev)
448		return true;
449
450	/* Don't suspend PHY if the attched netdev parent may wakeup.
451	 * The parent may point to a PCI device, as in tg3 driver.
452	 */
453	if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
454		return false;
455
456	/* Also don't suspend PHY if the netdev itself may wakeup. This
457	 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
458	 * e.g. SoC devices.
459	 */
460	if (device_may_wakeup(&netdev->dev))
461		return false;
462
463	return true;
464}
465
466static int mdio_bus_suspend(struct device *dev)
467{
468	struct phy_driver *phydrv = to_phy_driver(dev->driver);
469	struct phy_device *phydev = to_phy_device(dev);
470
471	/* We must stop the state machine manually, otherwise it stops out of
472	 * control, possibly with the phydev->lock held. Upon resume, netdev
473	 * may call phy routines that try to grab the same lock, and that may
474	 * lead to a deadlock.
475	 */
476	if (phydev->attached_dev && phydev->adjust_link)
477		phy_stop_machine(phydev);
478
479	if (!mdio_bus_phy_may_suspend(phydev))
480		return 0;
481
482	return phydrv->suspend(phydev);
483}
484
485static int mdio_bus_resume(struct device *dev)
486{
487	struct phy_driver *phydrv = to_phy_driver(dev->driver);
488	struct phy_device *phydev = to_phy_device(dev);
489	int ret;
490
491	if (!mdio_bus_phy_may_suspend(phydev))
492		goto no_resume;
493
494	ret = phydrv->resume(phydev);
495	if (ret < 0)
496		return ret;
497
498no_resume:
499	if (phydev->attached_dev && phydev->adjust_link)
500		phy_start_machine(phydev);
501
502	return 0;
503}
504
505static int mdio_bus_restore(struct device *dev)
506{
507	struct phy_device *phydev = to_phy_device(dev);
508	struct net_device *netdev = phydev->attached_dev;
509	int ret;
510
511	if (!netdev)
512		return 0;
513
514	ret = phy_init_hw(phydev);
515	if (ret < 0)
516		return ret;
517
518	/* The PHY needs to renegotiate. */
519	phydev->link = 0;
520	phydev->state = PHY_UP;
521
522	phy_start_machine(phydev);
523
524	return 0;
525}
526
527static const struct dev_pm_ops mdio_bus_pm_ops = {
528	.suspend = mdio_bus_suspend,
529	.resume = mdio_bus_resume,
530	.freeze = mdio_bus_suspend,
531	.thaw = mdio_bus_resume,
532	.restore = mdio_bus_restore,
533};
534
535#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
536
537#else
538
539#define MDIO_BUS_PM_OPS NULL
540
541#endif /* CONFIG_PM */
542
543static ssize_t
544phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
545{
546	struct phy_device *phydev = to_phy_device(dev);
547
548	return sprintf(buf, "0x%.8lx\n", (unsigned long)phydev->phy_id);
549}
550static DEVICE_ATTR_RO(phy_id);
551
552static ssize_t
553phy_interface_show(struct device *dev, struct device_attribute *attr, char *buf)
554{
555	struct phy_device *phydev = to_phy_device(dev);
556	const char *mode = NULL;
557
558	if (phy_is_internal(phydev))
559		mode = "internal";
560	else
561		mode = phy_modes(phydev->interface);
562
563	return sprintf(buf, "%s\n", mode);
564}
565static DEVICE_ATTR_RO(phy_interface);
566
567static ssize_t
568phy_has_fixups_show(struct device *dev, struct device_attribute *attr, char *buf)
569{
570	struct phy_device *phydev = to_phy_device(dev);
571
572	return sprintf(buf, "%d\n", phydev->has_fixups);
573}
574static DEVICE_ATTR_RO(phy_has_fixups);
575
576static struct attribute *mdio_dev_attrs[] = {
577	&dev_attr_phy_id.attr,
578	&dev_attr_phy_interface.attr,
579	&dev_attr_phy_has_fixups.attr,
580	NULL,
581};
582ATTRIBUTE_GROUPS(mdio_dev);
583
584struct bus_type mdio_bus_type = {
585	.name		= "mdio_bus",
586	.match		= mdio_bus_match,
587	.pm		= MDIO_BUS_PM_OPS,
588	.dev_groups	= mdio_dev_groups,
589};
590EXPORT_SYMBOL(mdio_bus_type);
591
592int __init mdio_bus_init(void)
593{
594	int ret;
595
596	ret = class_register(&mdio_bus_class);
597	if (!ret) {
598		ret = bus_register(&mdio_bus_type);
599		if (ret)
600			class_unregister(&mdio_bus_class);
601	}
602
603	return ret;
604}
605
606void mdio_bus_exit(void)
607{
608	class_unregister(&mdio_bus_class);
609	bus_unregister(&mdio_bus_type);
610}
611