1/*
2 * drivers/net/phy/mdio_bus.c
3 *
4 * MDIO Bus interface
5 *
6 * Author: Andy Fleming
7 *
8 * Copyright (c) 2004 Freescale Semiconductor, Inc.
9 *
10 * This program is free software; you can redistribute  it and/or modify it
11 * under  the terms of  the GNU General  Public License as published by the
12 * Free Software Foundation;  either version 2 of the  License, or (at your
13 * option) any later version.
14 *
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/netdevice.h>
26#include <linux/etherdevice.h>
27#include <linux/skbuff.h>
28#include <linux/spinlock.h>
29#include <linux/mm.h>
30#include <linux/module.h>
31#include <linux/mii.h>
32#include <linux/ethtool.h>
33#include <linux/phy.h>
34
35#include <asm/io.h>
36#include <asm/irq.h>
37#include <asm/uaccess.h>
38
39/**
40 * mdiobus_alloc_size - allocate a mii_bus structure
41 * @size: extra amount of memory to allocate for private storage.
42 * If non-zero, then bus->priv is points to that memory.
43 *
44 * Description: called by a bus driver to allocate an mii_bus
45 * structure to fill in.
46 */
47struct mii_bus *mdiobus_alloc_size(size_t size)
48{
49	struct mii_bus *bus;
50	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
51	size_t alloc_size;
52
53	/* If we alloc extra space, it should be aligned */
54	if (size)
55		alloc_size = aligned_size + size;
56	else
57		alloc_size = sizeof(*bus);
58
59	bus = kzalloc(alloc_size, GFP_KERNEL);
60	if (bus) {
61		bus->state = MDIOBUS_ALLOCATED;
62		if (size)
63			bus->priv = (void *)bus + aligned_size;
64	}
65
66	return bus;
67}
68EXPORT_SYMBOL(mdiobus_alloc_size);
69
70/**
71 * mdiobus_release - mii_bus device release callback
72 * @d: the target struct device that contains the mii_bus
73 *
74 * Description: called when the last reference to an mii_bus is
75 * dropped, to free the underlying memory.
76 */
77static void mdiobus_release(struct device *d)
78{
79	struct mii_bus *bus = to_mii_bus(d);
80	BUG_ON(bus->state != MDIOBUS_RELEASED &&
81	       /* for compatibility with error handling in drivers */
82	       bus->state != MDIOBUS_ALLOCATED);
83	kfree(bus);
84}
85
86static struct class mdio_bus_class = {
87	.name		= "mdio_bus",
88	.dev_release	= mdiobus_release,
89};
90
91/**
92 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
93 * @bus: target mii_bus
94 *
95 * Description: Called by a bus driver to bring up all the PHYs
96 *   on a given bus, and attach them to the bus.
97 *
98 * Returns 0 on success or < 0 on error.
99 */
100int mdiobus_register(struct mii_bus *bus)
101{
102	int i, err;
103
104	if (NULL == bus || NULL == bus->name ||
105			NULL == bus->read ||
106			NULL == bus->write)
107		return -EINVAL;
108
109	BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
110	       bus->state != MDIOBUS_UNREGISTERED);
111
112	bus->dev.parent = bus->parent;
113	bus->dev.class = &mdio_bus_class;
114	bus->dev.groups = NULL;
115	dev_set_name(&bus->dev, "%s", bus->id);
116
117	err = device_register(&bus->dev);
118	if (err) {
119		printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
120		return -EINVAL;
121	}
122
123	mutex_init(&bus->mdio_lock);
124
125	if (bus->reset)
126		bus->reset(bus);
127
128	for (i = 0; i < PHY_MAX_ADDR; i++) {
129		if ((bus->phy_mask & (1 << i)) == 0) {
130			struct phy_device *phydev;
131
132			phydev = mdiobus_scan(bus, i);
133			if (IS_ERR(phydev)) {
134				err = PTR_ERR(phydev);
135				goto error;
136			}
137		}
138	}
139
140	bus->state = MDIOBUS_REGISTERED;
141	pr_info("%s: probed\n", bus->name);
142	return 0;
143
144error:
145	while (--i >= 0) {
146		if (bus->phy_map[i])
147			device_unregister(&bus->phy_map[i]->dev);
148	}
149	device_del(&bus->dev);
150	return err;
151}
152EXPORT_SYMBOL(mdiobus_register);
153
154void mdiobus_unregister(struct mii_bus *bus)
155{
156	int i;
157
158	BUG_ON(bus->state != MDIOBUS_REGISTERED);
159	bus->state = MDIOBUS_UNREGISTERED;
160
161	device_del(&bus->dev);
162	for (i = 0; i < PHY_MAX_ADDR; i++) {
163		if (bus->phy_map[i])
164			device_unregister(&bus->phy_map[i]->dev);
165		bus->phy_map[i] = NULL;
166	}
167}
168EXPORT_SYMBOL(mdiobus_unregister);
169
170/**
171 * mdiobus_free - free a struct mii_bus
172 * @bus: mii_bus to free
173 *
174 * This function releases the reference to the underlying device
175 * object in the mii_bus.  If this is the last reference, the mii_bus
176 * will be freed.
177 */
178void mdiobus_free(struct mii_bus *bus)
179{
180	/*
181	 * For compatibility with error handling in drivers.
182	 */
183	if (bus->state == MDIOBUS_ALLOCATED) {
184		kfree(bus);
185		return;
186	}
187
188	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
189	bus->state = MDIOBUS_RELEASED;
190
191	put_device(&bus->dev);
192}
193EXPORT_SYMBOL(mdiobus_free);
194
195struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
196{
197	struct phy_device *phydev;
198	int err;
199
200	phydev = get_phy_device(bus, addr);
201	if (IS_ERR(phydev) || phydev == NULL)
202		return phydev;
203
204	err = phy_device_register(phydev);
205	if (err) {
206		phy_device_free(phydev);
207		return NULL;
208	}
209
210	return phydev;
211}
212EXPORT_SYMBOL(mdiobus_scan);
213
214/**
215 * mdiobus_read - Convenience function for reading a given MII mgmt register
216 * @bus: the mii_bus struct
217 * @addr: the phy address
218 * @regnum: register number to read
219 *
220 * NOTE: MUST NOT be called from interrupt context,
221 * because the bus read/write functions may wait for an interrupt
222 * to conclude the operation.
223 */
224int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
225{
226	int retval;
227
228	BUG_ON(in_interrupt());
229
230	mutex_lock(&bus->mdio_lock);
231	retval = bus->read(bus, addr, regnum);
232	mutex_unlock(&bus->mdio_lock);
233
234	return retval;
235}
236EXPORT_SYMBOL(mdiobus_read);
237
238/**
239 * mdiobus_write - Convenience function for writing a given MII mgmt register
240 * @bus: the mii_bus struct
241 * @addr: the phy address
242 * @regnum: register number to write
243 * @val: value to write to @regnum
244 *
245 * NOTE: MUST NOT be called from interrupt context,
246 * because the bus read/write functions may wait for an interrupt
247 * to conclude the operation.
248 */
249int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
250{
251	int err;
252
253	BUG_ON(in_interrupt());
254
255	mutex_lock(&bus->mdio_lock);
256	err = bus->write(bus, addr, regnum, val);
257	mutex_unlock(&bus->mdio_lock);
258
259	return err;
260}
261EXPORT_SYMBOL(mdiobus_write);
262
263/**
264 * mdio_bus_match - determine if given PHY driver supports the given PHY device
265 * @dev: target PHY device
266 * @drv: given PHY driver
267 *
268 * Description: Given a PHY device, and a PHY driver, return 1 if
269 *   the driver supports the device.  Otherwise, return 0.
270 */
271static int mdio_bus_match(struct device *dev, struct device_driver *drv)
272{
273	struct phy_device *phydev = to_phy_device(dev);
274	struct phy_driver *phydrv = to_phy_driver(drv);
275
276	return ((phydrv->phy_id & phydrv->phy_id_mask) ==
277		(phydev->phy_id & phydrv->phy_id_mask));
278}
279
280#ifdef CONFIG_PM
281
282static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
283{
284	struct device_driver *drv = phydev->dev.driver;
285	struct phy_driver *phydrv = to_phy_driver(drv);
286	struct net_device *netdev = phydev->attached_dev;
287
288	if (!drv || !phydrv->suspend)
289		return false;
290
291	/* PHY not attached? May suspend. */
292	if (!netdev)
293		return true;
294
295	/*
296	 * Don't suspend PHY if the attched netdev parent may wakeup.
297	 * The parent may point to a PCI device, as in tg3 driver.
298	 */
299	if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
300		return false;
301
302	/*
303	 * Also don't suspend PHY if the netdev itself may wakeup. This
304	 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
305	 * e.g. SoC devices.
306	 */
307	if (device_may_wakeup(&netdev->dev))
308		return false;
309
310	return true;
311}
312
313static int mdio_bus_suspend(struct device *dev)
314{
315	struct phy_driver *phydrv = to_phy_driver(dev->driver);
316	struct phy_device *phydev = to_phy_device(dev);
317
318	/*
319	 * We must stop the state machine manually, otherwise it stops out of
320	 * control, possibly with the phydev->lock held. Upon resume, netdev
321	 * may call phy routines that try to grab the same lock, and that may
322	 * lead to a deadlock.
323	 */
324	if (phydev->attached_dev && phydev->adjust_link)
325		phy_stop_machine(phydev);
326
327	if (!mdio_bus_phy_may_suspend(phydev))
328		return 0;
329
330	return phydrv->suspend(phydev);
331}
332
333static int mdio_bus_resume(struct device *dev)
334{
335	struct phy_driver *phydrv = to_phy_driver(dev->driver);
336	struct phy_device *phydev = to_phy_device(dev);
337	int ret;
338
339	if (!mdio_bus_phy_may_suspend(phydev))
340		goto no_resume;
341
342	ret = phydrv->resume(phydev);
343	if (ret < 0)
344		return ret;
345
346no_resume:
347	if (phydev->attached_dev && phydev->adjust_link)
348		phy_start_machine(phydev, NULL);
349
350	return 0;
351}
352
353static int mdio_bus_restore(struct device *dev)
354{
355	struct phy_device *phydev = to_phy_device(dev);
356	struct net_device *netdev = phydev->attached_dev;
357	int ret;
358
359	if (!netdev)
360		return 0;
361
362	ret = phy_init_hw(phydev);
363	if (ret < 0)
364		return ret;
365
366	/* The PHY needs to renegotiate. */
367	phydev->link = 0;
368	phydev->state = PHY_UP;
369
370	phy_start_machine(phydev, NULL);
371
372	return 0;
373}
374
375static struct dev_pm_ops mdio_bus_pm_ops = {
376	.suspend = mdio_bus_suspend,
377	.resume = mdio_bus_resume,
378	.freeze = mdio_bus_suspend,
379	.thaw = mdio_bus_resume,
380	.restore = mdio_bus_restore,
381};
382
383#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
384
385#else
386
387#define MDIO_BUS_PM_OPS NULL
388
389#endif /* CONFIG_PM */
390
391struct bus_type mdio_bus_type = {
392	.name		= "mdio_bus",
393	.match		= mdio_bus_match,
394	.pm		= MDIO_BUS_PM_OPS,
395};
396EXPORT_SYMBOL(mdio_bus_type);
397
398int __init mdio_bus_init(void)
399{
400	int ret;
401
402	ret = class_register(&mdio_bus_class);
403	if (!ret) {
404		ret = bus_register(&mdio_bus_type);
405		if (ret)
406			class_unregister(&mdio_bus_class);
407	}
408
409	return ret;
410}
411
412void mdio_bus_exit(void)
413{
414	class_unregister(&mdio_bus_class);
415	bus_unregister(&mdio_bus_type);
416}
417