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 */
mdiobus_alloc_size(size_t size)47 struct 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 }
68 EXPORT_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 */
mdiobus_release(struct device * d)77 static 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
86 static 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 */
mdiobus_register(struct mii_bus * bus)100 int 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
144 error:
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 }
152 EXPORT_SYMBOL(mdiobus_register);
153
mdiobus_unregister(struct mii_bus * bus)154 void 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 }
168 EXPORT_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 */
mdiobus_free(struct mii_bus * bus)178 void 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 }
193 EXPORT_SYMBOL(mdiobus_free);
194
mdiobus_scan(struct mii_bus * bus,int addr)195 struct 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 }
212 EXPORT_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 */
mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)224 int 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 }
236 EXPORT_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 */
mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)249 int 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 }
261 EXPORT_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 */
mdio_bus_match(struct device * dev,struct device_driver * drv)271 static 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
mdio_bus_phy_may_suspend(struct phy_device * phydev)282 static 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
mdio_bus_suspend(struct device * dev)313 static 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
mdio_bus_resume(struct device * dev)333 static 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
346 no_resume:
347 if (phydev->attached_dev && phydev->adjust_link)
348 phy_start_machine(phydev, NULL);
349
350 return 0;
351 }
352
mdio_bus_restore(struct device * dev)353 static 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
375 static 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
391 struct bus_type mdio_bus_type = {
392 .name = "mdio_bus",
393 .match = mdio_bus_match,
394 .pm = MDIO_BUS_PM_OPS,
395 };
396 EXPORT_SYMBOL(mdio_bus_type);
397
mdio_bus_init(void)398 int __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
mdio_bus_exit(void)412 void mdio_bus_exit(void)
413 {
414 class_unregister(&mdio_bus_class);
415 bus_unregister(&mdio_bus_type);
416 }
417