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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 - allocate a mii_bus structure
41 *
42 * Description: called by a bus driver to allocate an mii_bus
43 * structure to fill in.
44 */
45struct mii_bus *mdiobus_alloc(void)
46{
47 struct mii_bus *bus;
48
49 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
50 if (bus != NULL)
51 bus->state = MDIOBUS_ALLOCATED;
52
53 return bus;
54}
55EXPORT_SYMBOL(mdiobus_alloc);
56
57/**
58 * mdiobus_release - mii_bus device release callback
59 * @d: the target struct device that contains the mii_bus
60 *
61 * Description: called when the last reference to an mii_bus is
62 * dropped, to free the underlying memory.
63 */
64static void mdiobus_release(struct device *d)
65{
66 struct mii_bus *bus = to_mii_bus(d);
67 BUG_ON(bus->state != MDIOBUS_RELEASED &&
68 /* for compatibility with error handling in drivers */
69 bus->state != MDIOBUS_ALLOCATED);
70 kfree(bus);
71}
72
73static struct class mdio_bus_class = {
74 .name = "mdio_bus",
75 .dev_release = mdiobus_release,
76};
77
78/**
79 * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
80 * @bus: target mii_bus
81 *
82 * Description: Called by a bus driver to bring up all the PHYs
83 * on a given bus, and attach them to the bus.
84 *
85 * Returns 0 on success or < 0 on error.
86 */
87int mdiobus_register(struct mii_bus *bus)
88{
89 int i, err;
90
91 if (NULL == bus || NULL == bus->name ||
92 NULL == bus->read ||
93 NULL == bus->write)
94 return -EINVAL;
95
96 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
97 bus->state != MDIOBUS_UNREGISTERED);
98
99 bus->dev.parent = bus->parent;
100 bus->dev.class = &mdio_bus_class;
101 bus->dev.groups = NULL;
102 dev_set_name(&bus->dev, "%s", bus->id);
103
104 err = device_register(&bus->dev);
105 if (err) {
106 printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
107 return -EINVAL;
108 }
109
110 mutex_init(&bus->mdio_lock);
111
112 if (bus->reset)
113 bus->reset(bus);
114
115 for (i = 0; i < PHY_MAX_ADDR; i++) {
116 if ((bus->phy_mask & (1 << i)) == 0) {
117 struct phy_device *phydev;
118
119 phydev = mdiobus_scan(bus, i);
120 if (IS_ERR(phydev)) {
121 err = PTR_ERR(phydev);
122 goto error;
123 }
124 }
125 }
126
127 bus->state = MDIOBUS_REGISTERED;
128 pr_info("%s: probed\n", bus->name);
129 return 0;
130
131error:
132 while (--i >= 0) {
133 if (bus->phy_map[i])
134 device_unregister(&bus->phy_map[i]->dev);
135 }
136 device_del(&bus->dev);
137 return err;
138}
139EXPORT_SYMBOL(mdiobus_register);
140
141void mdiobus_unregister(struct mii_bus *bus)
142{
143 int i;
144
145 BUG_ON(bus->state != MDIOBUS_REGISTERED);
146 bus->state = MDIOBUS_UNREGISTERED;
147
148 device_del(&bus->dev);
149 for (i = 0; i < PHY_MAX_ADDR; i++) {
150 if (bus->phy_map[i])
151 device_unregister(&bus->phy_map[i]->dev);
152 bus->phy_map[i] = NULL;
153 }
154}
155EXPORT_SYMBOL(mdiobus_unregister);
156
157/**
158 * mdiobus_free - free a struct mii_bus
159 * @bus: mii_bus to free
160 *
161 * This function releases the reference to the underlying device
162 * object in the mii_bus. If this is the last reference, the mii_bus
163 * will be freed.
164 */
165void mdiobus_free(struct mii_bus *bus)
166{
167 /*
168 * For compatibility with error handling in drivers.
169 */
170 if (bus->state == MDIOBUS_ALLOCATED) {
171 kfree(bus);
172 return;
173 }
174
175 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
176 bus->state = MDIOBUS_RELEASED;
177
178 put_device(&bus->dev);
179}
180EXPORT_SYMBOL(mdiobus_free);
181
182struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
183{
184 struct phy_device *phydev;
185 int err;
186
187 phydev = get_phy_device(bus, addr);
188 if (IS_ERR(phydev) || phydev == NULL)
189 return phydev;
190
191 err = phy_device_register(phydev);
192 if (err) {
193 phy_device_free(phydev);
194 return NULL;
195 }
196
197 return phydev;
198}
199EXPORT_SYMBOL(mdiobus_scan);
200
201/**
202 * mdiobus_read - Convenience function for reading a given MII mgmt register
203 * @bus: the mii_bus struct
204 * @addr: the phy address
205 * @regnum: register number to read
206 *
207 * NOTE: MUST NOT be called from interrupt context,
208 * because the bus read/write functions may wait for an interrupt
209 * to conclude the operation.
210 */
211int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
212{
213 int retval;
214
215 BUG_ON(in_interrupt());
216
217 mutex_lock(&bus->mdio_lock);
218 retval = bus->read(bus, addr, regnum);
219 mutex_unlock(&bus->mdio_lock);
220
221 return retval;
222}
223EXPORT_SYMBOL(mdiobus_read);
224
225/**
226 * mdiobus_write - Convenience function for writing a given MII mgmt register
227 * @bus: the mii_bus struct
228 * @addr: the phy address
229 * @regnum: register number to write
230 * @val: value to write to @regnum
231 *
232 * NOTE: MUST NOT be called from interrupt context,
233 * because the bus read/write functions may wait for an interrupt
234 * to conclude the operation.
235 */
236int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
237{
238 int err;
239
240 BUG_ON(in_interrupt());
241
242 mutex_lock(&bus->mdio_lock);
243 err = bus->write(bus, addr, regnum, val);
244 mutex_unlock(&bus->mdio_lock);
245
246 return err;
247}
248EXPORT_SYMBOL(mdiobus_write);
249
250/**
251 * mdio_bus_match - determine if given PHY driver supports the given PHY device
252 * @dev: target PHY device
253 * @drv: given PHY driver
254 *
255 * Description: Given a PHY device, and a PHY driver, return 1 if
256 * the driver supports the device. Otherwise, return 0.
257 */
258static int mdio_bus_match(struct device *dev, struct device_driver *drv)
259{
260 struct phy_device *phydev = to_phy_device(dev);
261 struct phy_driver *phydrv = to_phy_driver(drv);
262
263 return ((phydrv->phy_id & phydrv->phy_id_mask) ==
264 (phydev->phy_id & phydrv->phy_id_mask));
265}
266
267#ifdef CONFIG_PM
268
269static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
270{
271 struct device_driver *drv = phydev->dev.driver;
272 struct phy_driver *phydrv = to_phy_driver(drv);
273 struct net_device *netdev = phydev->attached_dev;
274
275 if (!drv || !phydrv->suspend)
276 return false;
277
278 /* PHY not attached? May suspend. */
279 if (!netdev)
280 return true;
281
282 /*
283 * Don't suspend PHY if the attched netdev parent may wakeup.
284 * The parent may point to a PCI device, as in tg3 driver.
285 */
286 if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
287 return false;
288
289 /*
290 * Also don't suspend PHY if the netdev itself may wakeup. This
291 * is the case for devices w/o underlaying pwr. mgmt. aware bus,
292 * e.g. SoC devices.
293 */
294 if (device_may_wakeup(&netdev->dev))
295 return false;
296
297 return true;
298}
299
300static int mdio_bus_suspend(struct device *dev)
301{
302 struct phy_driver *phydrv = to_phy_driver(dev->driver);
303 struct phy_device *phydev = to_phy_device(dev);
304
305 /*
306 * We must stop the state machine manually, otherwise it stops out of
307 * control, possibly with the phydev->lock held. Upon resume, netdev
308 * may call phy routines that try to grab the same lock, and that may
309 * lead to a deadlock.
310 */
311 if (phydev->attached_dev && phydev->adjust_link)
312 phy_stop_machine(phydev);
313
314 if (!mdio_bus_phy_may_suspend(phydev))
315 return 0;
316
317 return phydrv->suspend(phydev);
318}
319
320static int mdio_bus_resume(struct device *dev)
321{
322 struct phy_driver *phydrv = to_phy_driver(dev->driver);
323 struct phy_device *phydev = to_phy_device(dev);
324 int ret;
325
326 if (!mdio_bus_phy_may_suspend(phydev))
327 goto no_resume;
328
329 ret = phydrv->resume(phydev);
330 if (ret < 0)
331 return ret;
332
333no_resume:
334 if (phydev->attached_dev && phydev->adjust_link)
335 phy_start_machine(phydev, NULL);
336
337 return 0;
338}
339
340static int mdio_bus_restore(struct device *dev)
341{
342 struct phy_device *phydev = to_phy_device(dev);
343 struct net_device *netdev = phydev->attached_dev;
344 int ret;
345
346 if (!netdev)
347 return 0;
348
349 ret = phy_init_hw(phydev);
350 if (ret < 0)
351 return ret;
352
353 /* The PHY needs to renegotiate. */
354 phydev->link = 0;
355 phydev->state = PHY_UP;
356
357 phy_start_machine(phydev, NULL);
358
359 return 0;
360}
361
362static struct dev_pm_ops mdio_bus_pm_ops = {
363 .suspend = mdio_bus_suspend,
364 .resume = mdio_bus_resume,
365 .freeze = mdio_bus_suspend,
366 .thaw = mdio_bus_resume,
367 .restore = mdio_bus_restore,
368};
369
370#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
371
372#else
373
374#define MDIO_BUS_PM_OPS NULL
375
376#endif /* CONFIG_PM */
377
378struct bus_type mdio_bus_type = {
379 .name = "mdio_bus",
380 .match = mdio_bus_match,
381 .pm = MDIO_BUS_PM_OPS,
382};
383EXPORT_SYMBOL(mdio_bus_type);
384
385int __init mdio_bus_init(void)
386{
387 int ret;
388
389 ret = class_register(&mdio_bus_class);
390 if (!ret) {
391 ret = bus_register(&mdio_bus_type);
392 if (ret)
393 class_unregister(&mdio_bus_class);
394 }
395
396 return ret;
397}
398
399void mdio_bus_exit(void)
400{
401 class_unregister(&mdio_bus_class);
402 bus_unregister(&mdio_bus_type);
403}
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
41int mdiobus_register_device(struct mdio_device *mdiodev)
42{
43 if (mdiodev->bus->mdio_map[mdiodev->addr])
44 return -EBUSY;
45
46 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
47
48 return 0;
49}
50EXPORT_SYMBOL(mdiobus_register_device);
51
52int mdiobus_unregister_device(struct mdio_device *mdiodev)
53{
54 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
55 return -EINVAL;
56
57 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
58
59 return 0;
60}
61EXPORT_SYMBOL(mdiobus_unregister_device);
62
63struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
64{
65 struct mdio_device *mdiodev = bus->mdio_map[addr];
66
67 if (!mdiodev)
68 return NULL;
69
70 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
71 return NULL;
72
73 return container_of(mdiodev, struct phy_device, mdio);
74}
75EXPORT_SYMBOL(mdiobus_get_phy);
76
77bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
78{
79 return bus->mdio_map[addr];
80}
81EXPORT_SYMBOL(mdiobus_is_registered_device);
82
83/**
84 * mdiobus_alloc_size - allocate a mii_bus structure
85 * @size: extra amount of memory to allocate for private storage.
86 * If non-zero, then bus->priv is points to that memory.
87 *
88 * Description: called by a bus driver to allocate an mii_bus
89 * structure to fill in.
90 */
91struct mii_bus *mdiobus_alloc_size(size_t size)
92{
93 struct mii_bus *bus;
94 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
95 size_t alloc_size;
96 int i;
97
98 /* If we alloc extra space, it should be aligned */
99 if (size)
100 alloc_size = aligned_size + size;
101 else
102 alloc_size = sizeof(*bus);
103
104 bus = kzalloc(alloc_size, GFP_KERNEL);
105 if (!bus)
106 return NULL;
107
108 bus->state = MDIOBUS_ALLOCATED;
109 if (size)
110 bus->priv = (void *)bus + aligned_size;
111
112 /* Initialise the interrupts to polling */
113 for (i = 0; i < PHY_MAX_ADDR; i++)
114 bus->irq[i] = PHY_POLL;
115
116 return bus;
117}
118EXPORT_SYMBOL(mdiobus_alloc_size);
119
120static void _devm_mdiobus_free(struct device *dev, void *res)
121{
122 mdiobus_free(*(struct mii_bus **)res);
123}
124
125static int devm_mdiobus_match(struct device *dev, void *res, void *data)
126{
127 struct mii_bus **r = res;
128
129 if (WARN_ON(!r || !*r))
130 return 0;
131
132 return *r == data;
133}
134
135/**
136 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
137 * @dev: Device to allocate mii_bus for
138 * @sizeof_priv: Space to allocate for private structure.
139 *
140 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
141 * automatically freed on driver detach.
142 *
143 * If an mii_bus allocated with this function needs to be freed separately,
144 * devm_mdiobus_free() must be used.
145 *
146 * RETURNS:
147 * Pointer to allocated mii_bus on success, NULL on failure.
148 */
149struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
150{
151 struct mii_bus **ptr, *bus;
152
153 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
154 if (!ptr)
155 return NULL;
156
157 /* use raw alloc_dr for kmalloc caller tracing */
158 bus = mdiobus_alloc_size(sizeof_priv);
159 if (bus) {
160 *ptr = bus;
161 devres_add(dev, ptr);
162 } else {
163 devres_free(ptr);
164 }
165
166 return bus;
167}
168EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
169
170/**
171 * devm_mdiobus_free - Resource-managed mdiobus_free()
172 * @dev: Device this mii_bus belongs to
173 * @bus: the mii_bus associated with the device
174 *
175 * Free mii_bus allocated with devm_mdiobus_alloc_size().
176 */
177void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
178{
179 int rc;
180
181 rc = devres_release(dev, _devm_mdiobus_free,
182 devm_mdiobus_match, bus);
183 WARN_ON(rc);
184}
185EXPORT_SYMBOL_GPL(devm_mdiobus_free);
186
187/**
188 * mdiobus_release - mii_bus device release callback
189 * @d: the target struct device that contains the mii_bus
190 *
191 * Description: called when the last reference to an mii_bus is
192 * dropped, to free the underlying memory.
193 */
194static void mdiobus_release(struct device *d)
195{
196 struct mii_bus *bus = to_mii_bus(d);
197 BUG_ON(bus->state != MDIOBUS_RELEASED &&
198 /* for compatibility with error handling in drivers */
199 bus->state != MDIOBUS_ALLOCATED);
200 kfree(bus);
201}
202
203static struct class mdio_bus_class = {
204 .name = "mdio_bus",
205 .dev_release = mdiobus_release,
206};
207
208#if IS_ENABLED(CONFIG_OF_MDIO)
209/* Helper function for of_mdio_find_bus */
210static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
211{
212 return dev->of_node == mdio_bus_np;
213}
214/**
215 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
216 * @mdio_bus_np: Pointer to the mii_bus.
217 *
218 * Returns a reference to the mii_bus, or NULL if none found. The
219 * embedded struct device will have its reference count incremented,
220 * and this must be put once the bus is finished with.
221 *
222 * Because the association of a device_node and mii_bus is made via
223 * of_mdiobus_register(), the mii_bus cannot be found before it is
224 * registered with of_mdiobus_register().
225 *
226 */
227struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
228{
229 struct device *d;
230
231 if (!mdio_bus_np)
232 return NULL;
233
234 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
235 of_mdio_bus_match);
236
237 return d ? to_mii_bus(d) : NULL;
238}
239EXPORT_SYMBOL(of_mdio_find_bus);
240
241/* Walk the list of subnodes of a mdio bus and look for a node that
242 * matches the mdio device's address with its 'reg' property. If
243 * found, set the of_node pointer for the mdio device. This allows
244 * auto-probed phy devices to be supplied with information passed in
245 * via DT.
246 */
247static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
248 struct mdio_device *mdiodev)
249{
250 struct device *dev = &mdiodev->dev;
251 struct device_node *child;
252
253 if (dev->of_node || !bus->dev.of_node)
254 return;
255
256 for_each_available_child_of_node(bus->dev.of_node, child) {
257 int addr;
258 int ret;
259
260 ret = of_property_read_u32(child, "reg", &addr);
261 if (ret < 0) {
262 dev_err(dev, "%s has invalid MDIO address\n",
263 child->full_name);
264 continue;
265 }
266
267 /* A MDIO device must have a reg property in the range [0-31] */
268 if (addr >= PHY_MAX_ADDR) {
269 dev_err(dev, "%s MDIO address %i is too large\n",
270 child->full_name, addr);
271 continue;
272 }
273
274 if (addr == mdiodev->addr) {
275 dev->of_node = child;
276 return;
277 }
278 }
279}
280#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
281static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
282 struct mdio_device *mdiodev)
283{
284}
285#endif
286
287/**
288 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
289 * @bus: target mii_bus
290 * @owner: module containing bus accessor functions
291 *
292 * Description: Called by a bus driver to bring up all the PHYs
293 * on a given bus, and attach them to the bus. Drivers should use
294 * mdiobus_register() rather than __mdiobus_register() unless they
295 * need to pass a specific owner module. MDIO devices which are not
296 * PHYs will not be brought up by this function. They are expected to
297 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
298 *
299 * Returns 0 on success or < 0 on error.
300 */
301int __mdiobus_register(struct mii_bus *bus, struct module *owner)
302{
303 struct mdio_device *mdiodev;
304 int i, err;
305
306 if (NULL == bus || NULL == bus->name ||
307 NULL == bus->read || NULL == bus->write)
308 return -EINVAL;
309
310 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
311 bus->state != MDIOBUS_UNREGISTERED);
312
313 bus->owner = owner;
314 bus->dev.parent = bus->parent;
315 bus->dev.class = &mdio_bus_class;
316 bus->dev.groups = NULL;
317 dev_set_name(&bus->dev, "%s", bus->id);
318
319 err = device_register(&bus->dev);
320 if (err) {
321 pr_err("mii_bus %s failed to register\n", bus->id);
322 put_device(&bus->dev);
323 return -EINVAL;
324 }
325
326 mutex_init(&bus->mdio_lock);
327
328 if (bus->reset)
329 bus->reset(bus);
330
331 for (i = 0; i < PHY_MAX_ADDR; i++) {
332 if ((bus->phy_mask & (1 << i)) == 0) {
333 struct phy_device *phydev;
334
335 phydev = mdiobus_scan(bus, i);
336 if (IS_ERR(phydev)) {
337 err = PTR_ERR(phydev);
338 goto error;
339 }
340 }
341 }
342
343 bus->state = MDIOBUS_REGISTERED;
344 pr_info("%s: probed\n", bus->name);
345 return 0;
346
347error:
348 while (--i >= 0) {
349 mdiodev = bus->mdio_map[i];
350 if (!mdiodev)
351 continue;
352
353 mdiodev->device_remove(mdiodev);
354 mdiodev->device_free(mdiodev);
355 }
356 device_del(&bus->dev);
357 return err;
358}
359EXPORT_SYMBOL(__mdiobus_register);
360
361void mdiobus_unregister(struct mii_bus *bus)
362{
363 struct mdio_device *mdiodev;
364 int i;
365
366 BUG_ON(bus->state != MDIOBUS_REGISTERED);
367 bus->state = MDIOBUS_UNREGISTERED;
368
369 for (i = 0; i < PHY_MAX_ADDR; i++) {
370 mdiodev = bus->mdio_map[i];
371 if (!mdiodev)
372 continue;
373
374 mdiodev->device_remove(mdiodev);
375 mdiodev->device_free(mdiodev);
376 }
377 device_del(&bus->dev);
378}
379EXPORT_SYMBOL(mdiobus_unregister);
380
381/**
382 * mdiobus_free - free a struct mii_bus
383 * @bus: mii_bus to free
384 *
385 * This function releases the reference to the underlying device
386 * object in the mii_bus. If this is the last reference, the mii_bus
387 * will be freed.
388 */
389void mdiobus_free(struct mii_bus *bus)
390{
391 /* For compatibility with error handling in drivers. */
392 if (bus->state == MDIOBUS_ALLOCATED) {
393 kfree(bus);
394 return;
395 }
396
397 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
398 bus->state = MDIOBUS_RELEASED;
399
400 put_device(&bus->dev);
401}
402EXPORT_SYMBOL(mdiobus_free);
403
404/**
405 * mdiobus_scan - scan a bus for MDIO devices.
406 * @bus: mii_bus to scan
407 * @addr: address on bus to scan
408 *
409 * This function scans the MDIO bus, looking for devices which can be
410 * identified using a vendor/product ID in registers 2 and 3. Not all
411 * MDIO devices have such registers, but PHY devices typically
412 * do. Hence this function assumes anything found is a PHY, or can be
413 * treated as a PHY. Other MDIO devices, such as switches, will
414 * probably not be found during the scan.
415 */
416struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
417{
418 struct phy_device *phydev;
419 int err;
420
421 phydev = get_phy_device(bus, addr, false);
422 if (IS_ERR(phydev) || phydev == NULL)
423 return phydev;
424
425 /*
426 * For DT, see if the auto-probed phy has a correspoding child
427 * in the bus node, and set the of_node pointer in this case.
428 */
429 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
430
431 err = phy_device_register(phydev);
432 if (err) {
433 phy_device_free(phydev);
434 return NULL;
435 }
436
437 return phydev;
438}
439EXPORT_SYMBOL(mdiobus_scan);
440
441/**
442 * mdiobus_read_nested - Nested version of the mdiobus_read function
443 * @bus: the mii_bus struct
444 * @addr: the phy address
445 * @regnum: register number to read
446 *
447 * In case of nested MDIO bus access avoid lockdep false positives by
448 * using mutex_lock_nested().
449 *
450 * NOTE: MUST NOT be called from interrupt context,
451 * because the bus read/write functions may wait for an interrupt
452 * to conclude the operation.
453 */
454int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
455{
456 int retval;
457
458 BUG_ON(in_interrupt());
459
460 mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
461 retval = bus->read(bus, addr, regnum);
462 mutex_unlock(&bus->mdio_lock);
463
464 return retval;
465}
466EXPORT_SYMBOL(mdiobus_read_nested);
467
468/**
469 * mdiobus_read - Convenience function for reading a given MII mgmt register
470 * @bus: the mii_bus struct
471 * @addr: the phy address
472 * @regnum: register number to read
473 *
474 * NOTE: MUST NOT be called from interrupt context,
475 * because the bus read/write functions may wait for an interrupt
476 * to conclude the operation.
477 */
478int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
479{
480 int retval;
481
482 BUG_ON(in_interrupt());
483
484 mutex_lock(&bus->mdio_lock);
485 retval = bus->read(bus, addr, regnum);
486 mutex_unlock(&bus->mdio_lock);
487
488 return retval;
489}
490EXPORT_SYMBOL(mdiobus_read);
491
492/**
493 * mdiobus_write_nested - Nested version of the mdiobus_write function
494 * @bus: the mii_bus struct
495 * @addr: the phy address
496 * @regnum: register number to write
497 * @val: value to write to @regnum
498 *
499 * In case of nested MDIO bus access avoid lockdep false positives by
500 * using mutex_lock_nested().
501 *
502 * NOTE: MUST NOT be called from interrupt context,
503 * because the bus read/write functions may wait for an interrupt
504 * to conclude the operation.
505 */
506int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
507{
508 int err;
509
510 BUG_ON(in_interrupt());
511
512 mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
513 err = bus->write(bus, addr, regnum, val);
514 mutex_unlock(&bus->mdio_lock);
515
516 return err;
517}
518EXPORT_SYMBOL(mdiobus_write_nested);
519
520/**
521 * mdiobus_write - Convenience function for writing a given MII mgmt register
522 * @bus: the mii_bus struct
523 * @addr: the phy address
524 * @regnum: register number to write
525 * @val: value to write to @regnum
526 *
527 * NOTE: MUST NOT be called from interrupt context,
528 * because the bus read/write functions may wait for an interrupt
529 * to conclude the operation.
530 */
531int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
532{
533 int err;
534
535 BUG_ON(in_interrupt());
536
537 mutex_lock(&bus->mdio_lock);
538 err = bus->write(bus, addr, regnum, val);
539 mutex_unlock(&bus->mdio_lock);
540
541 return err;
542}
543EXPORT_SYMBOL(mdiobus_write);
544
545/**
546 * mdio_bus_match - determine if given MDIO driver supports the given
547 * MDIO device
548 * @dev: target MDIO device
549 * @drv: given MDIO driver
550 *
551 * Description: Given a MDIO device, and a MDIO driver, return 1 if
552 * the driver supports the device. Otherwise, return 0. This may
553 * require calling the devices own match function, since different classes
554 * of MDIO devices have different match criteria.
555 */
556static int mdio_bus_match(struct device *dev, struct device_driver *drv)
557{
558 struct mdio_device *mdio = to_mdio_device(dev);
559
560 if (of_driver_match_device(dev, drv))
561 return 1;
562
563 if (mdio->bus_match)
564 return mdio->bus_match(dev, drv);
565
566 return 0;
567}
568
569#ifdef CONFIG_PM
570static int mdio_bus_suspend(struct device *dev)
571{
572 struct mdio_device *mdio = to_mdio_device(dev);
573
574 if (mdio->pm_ops && mdio->pm_ops->suspend)
575 return mdio->pm_ops->suspend(dev);
576
577 return 0;
578}
579
580static int mdio_bus_resume(struct device *dev)
581{
582 struct mdio_device *mdio = to_mdio_device(dev);
583
584 if (mdio->pm_ops && mdio->pm_ops->resume)
585 return mdio->pm_ops->resume(dev);
586
587 return 0;
588}
589
590static int mdio_bus_restore(struct device *dev)
591{
592 struct mdio_device *mdio = to_mdio_device(dev);
593
594 if (mdio->pm_ops && mdio->pm_ops->restore)
595 return mdio->pm_ops->restore(dev);
596
597 return 0;
598}
599
600static const struct dev_pm_ops mdio_bus_pm_ops = {
601 .suspend = mdio_bus_suspend,
602 .resume = mdio_bus_resume,
603 .freeze = mdio_bus_suspend,
604 .thaw = mdio_bus_resume,
605 .restore = mdio_bus_restore,
606};
607
608#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
609
610#else
611
612#define MDIO_BUS_PM_OPS NULL
613
614#endif /* CONFIG_PM */
615
616struct bus_type mdio_bus_type = {
617 .name = "mdio_bus",
618 .match = mdio_bus_match,
619 .pm = MDIO_BUS_PM_OPS,
620};
621EXPORT_SYMBOL(mdio_bus_type);
622
623int __init mdio_bus_init(void)
624{
625 int ret;
626
627 ret = class_register(&mdio_bus_class);
628 if (!ret) {
629 ret = bus_register(&mdio_bus_type);
630 if (ret)
631 class_unregister(&mdio_bus_class);
632 }
633
634 return ret;
635}
636
637void mdio_bus_exit(void)
638{
639 class_unregister(&mdio_bus_class);
640 bus_unregister(&mdio_bus_type);
641}