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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
41#define CREATE_TRACE_POINTS
42#include <trace/events/mdio.h>
43
44int mdiobus_register_device(struct mdio_device *mdiodev)
45{
46 if (mdiodev->bus->mdio_map[mdiodev->addr])
47 return -EBUSY;
48
49 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
50
51 return 0;
52}
53EXPORT_SYMBOL(mdiobus_register_device);
54
55int mdiobus_unregister_device(struct mdio_device *mdiodev)
56{
57 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
58 return -EINVAL;
59
60 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
61
62 return 0;
63}
64EXPORT_SYMBOL(mdiobus_unregister_device);
65
66struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
67{
68 struct mdio_device *mdiodev = bus->mdio_map[addr];
69
70 if (!mdiodev)
71 return NULL;
72
73 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
74 return NULL;
75
76 return container_of(mdiodev, struct phy_device, mdio);
77}
78EXPORT_SYMBOL(mdiobus_get_phy);
79
80bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
81{
82 return bus->mdio_map[addr];
83}
84EXPORT_SYMBOL(mdiobus_is_registered_device);
85
86/**
87 * mdiobus_alloc_size - allocate a mii_bus structure
88 * @size: extra amount of memory to allocate for private storage.
89 * If non-zero, then bus->priv is points to that memory.
90 *
91 * Description: called by a bus driver to allocate an mii_bus
92 * structure to fill in.
93 */
94struct mii_bus *mdiobus_alloc_size(size_t size)
95{
96 struct mii_bus *bus;
97 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
98 size_t alloc_size;
99 int i;
100
101 /* If we alloc extra space, it should be aligned */
102 if (size)
103 alloc_size = aligned_size + size;
104 else
105 alloc_size = sizeof(*bus);
106
107 bus = kzalloc(alloc_size, GFP_KERNEL);
108 if (!bus)
109 return NULL;
110
111 bus->state = MDIOBUS_ALLOCATED;
112 if (size)
113 bus->priv = (void *)bus + aligned_size;
114
115 /* Initialise the interrupts to polling */
116 for (i = 0; i < PHY_MAX_ADDR; i++)
117 bus->irq[i] = PHY_POLL;
118
119 return bus;
120}
121EXPORT_SYMBOL(mdiobus_alloc_size);
122
123static void _devm_mdiobus_free(struct device *dev, void *res)
124{
125 mdiobus_free(*(struct mii_bus **)res);
126}
127
128static int devm_mdiobus_match(struct device *dev, void *res, void *data)
129{
130 struct mii_bus **r = res;
131
132 if (WARN_ON(!r || !*r))
133 return 0;
134
135 return *r == data;
136}
137
138/**
139 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
140 * @dev: Device to allocate mii_bus for
141 * @sizeof_priv: Space to allocate for private structure.
142 *
143 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
144 * automatically freed on driver detach.
145 *
146 * If an mii_bus allocated with this function needs to be freed separately,
147 * devm_mdiobus_free() must be used.
148 *
149 * RETURNS:
150 * Pointer to allocated mii_bus on success, NULL on failure.
151 */
152struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
153{
154 struct mii_bus **ptr, *bus;
155
156 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
157 if (!ptr)
158 return NULL;
159
160 /* use raw alloc_dr for kmalloc caller tracing */
161 bus = mdiobus_alloc_size(sizeof_priv);
162 if (bus) {
163 *ptr = bus;
164 devres_add(dev, ptr);
165 } else {
166 devres_free(ptr);
167 }
168
169 return bus;
170}
171EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
172
173/**
174 * devm_mdiobus_free - Resource-managed mdiobus_free()
175 * @dev: Device this mii_bus belongs to
176 * @bus: the mii_bus associated with the device
177 *
178 * Free mii_bus allocated with devm_mdiobus_alloc_size().
179 */
180void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
181{
182 int rc;
183
184 rc = devres_release(dev, _devm_mdiobus_free,
185 devm_mdiobus_match, bus);
186 WARN_ON(rc);
187}
188EXPORT_SYMBOL_GPL(devm_mdiobus_free);
189
190/**
191 * mdiobus_release - mii_bus device release callback
192 * @d: the target struct device that contains the mii_bus
193 *
194 * Description: called when the last reference to an mii_bus is
195 * dropped, to free the underlying memory.
196 */
197static void mdiobus_release(struct device *d)
198{
199 struct mii_bus *bus = to_mii_bus(d);
200 BUG_ON(bus->state != MDIOBUS_RELEASED &&
201 /* for compatibility with error handling in drivers */
202 bus->state != MDIOBUS_ALLOCATED);
203 kfree(bus);
204}
205
206static struct class mdio_bus_class = {
207 .name = "mdio_bus",
208 .dev_release = mdiobus_release,
209};
210
211#if IS_ENABLED(CONFIG_OF_MDIO)
212/* Helper function for of_mdio_find_bus */
213static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
214{
215 return dev->of_node == mdio_bus_np;
216}
217/**
218 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
219 * @mdio_bus_np: Pointer to the mii_bus.
220 *
221 * Returns a reference to the mii_bus, or NULL if none found. The
222 * embedded struct device will have its reference count incremented,
223 * and this must be put once the bus is finished with.
224 *
225 * Because the association of a device_node and mii_bus is made via
226 * of_mdiobus_register(), the mii_bus cannot be found before it is
227 * registered with of_mdiobus_register().
228 *
229 */
230struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
231{
232 struct device *d;
233
234 if (!mdio_bus_np)
235 return NULL;
236
237 d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
238 of_mdio_bus_match);
239
240 return d ? to_mii_bus(d) : NULL;
241}
242EXPORT_SYMBOL(of_mdio_find_bus);
243
244/* Walk the list of subnodes of a mdio bus and look for a node that
245 * matches the mdio device's address with its 'reg' property. If
246 * found, set the of_node pointer for the mdio device. This allows
247 * auto-probed phy devices to be supplied with information passed in
248 * via DT.
249 */
250static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
251 struct mdio_device *mdiodev)
252{
253 struct device *dev = &mdiodev->dev;
254 struct device_node *child;
255
256 if (dev->of_node || !bus->dev.of_node)
257 return;
258
259 for_each_available_child_of_node(bus->dev.of_node, child) {
260 int addr;
261 int ret;
262
263 ret = of_property_read_u32(child, "reg", &addr);
264 if (ret < 0) {
265 dev_err(dev, "%s has invalid MDIO address\n",
266 child->full_name);
267 continue;
268 }
269
270 /* A MDIO device must have a reg property in the range [0-31] */
271 if (addr >= PHY_MAX_ADDR) {
272 dev_err(dev, "%s MDIO address %i is too large\n",
273 child->full_name, addr);
274 continue;
275 }
276
277 if (addr == mdiodev->addr) {
278 dev->of_node = child;
279 return;
280 }
281 }
282}
283#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
284static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
285 struct mdio_device *mdiodev)
286{
287}
288#endif
289
290/**
291 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
292 * @bus: target mii_bus
293 * @owner: module containing bus accessor functions
294 *
295 * Description: Called by a bus driver to bring up all the PHYs
296 * on a given bus, and attach them to the bus. Drivers should use
297 * mdiobus_register() rather than __mdiobus_register() unless they
298 * need to pass a specific owner module. MDIO devices which are not
299 * PHYs will not be brought up by this function. They are expected to
300 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
301 *
302 * Returns 0 on success or < 0 on error.
303 */
304int __mdiobus_register(struct mii_bus *bus, struct module *owner)
305{
306 struct mdio_device *mdiodev;
307 int i, err;
308
309 if (NULL == bus || NULL == bus->name ||
310 NULL == bus->read || NULL == bus->write)
311 return -EINVAL;
312
313 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
314 bus->state != MDIOBUS_UNREGISTERED);
315
316 bus->owner = owner;
317 bus->dev.parent = bus->parent;
318 bus->dev.class = &mdio_bus_class;
319 bus->dev.groups = NULL;
320 dev_set_name(&bus->dev, "%s", bus->id);
321
322 err = device_register(&bus->dev);
323 if (err) {
324 pr_err("mii_bus %s failed to register\n", bus->id);
325 put_device(&bus->dev);
326 return -EINVAL;
327 }
328
329 mutex_init(&bus->mdio_lock);
330
331 if (bus->reset)
332 bus->reset(bus);
333
334 for (i = 0; i < PHY_MAX_ADDR; i++) {
335 if ((bus->phy_mask & (1 << i)) == 0) {
336 struct phy_device *phydev;
337
338 phydev = mdiobus_scan(bus, i);
339 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
340 err = PTR_ERR(phydev);
341 goto error;
342 }
343 }
344 }
345
346 bus->state = MDIOBUS_REGISTERED;
347 pr_info("%s: probed\n", bus->name);
348 return 0;
349
350error:
351 while (--i >= 0) {
352 mdiodev = bus->mdio_map[i];
353 if (!mdiodev)
354 continue;
355
356 mdiodev->device_remove(mdiodev);
357 mdiodev->device_free(mdiodev);
358 }
359 device_del(&bus->dev);
360 return err;
361}
362EXPORT_SYMBOL(__mdiobus_register);
363
364void mdiobus_unregister(struct mii_bus *bus)
365{
366 struct mdio_device *mdiodev;
367 int i;
368
369 BUG_ON(bus->state != MDIOBUS_REGISTERED);
370 bus->state = MDIOBUS_UNREGISTERED;
371
372 for (i = 0; i < PHY_MAX_ADDR; i++) {
373 mdiodev = bus->mdio_map[i];
374 if (!mdiodev)
375 continue;
376
377 mdiodev->device_remove(mdiodev);
378 mdiodev->device_free(mdiodev);
379 }
380 device_del(&bus->dev);
381}
382EXPORT_SYMBOL(mdiobus_unregister);
383
384/**
385 * mdiobus_free - free a struct mii_bus
386 * @bus: mii_bus to free
387 *
388 * This function releases the reference to the underlying device
389 * object in the mii_bus. If this is the last reference, the mii_bus
390 * will be freed.
391 */
392void mdiobus_free(struct mii_bus *bus)
393{
394 /* For compatibility with error handling in drivers. */
395 if (bus->state == MDIOBUS_ALLOCATED) {
396 kfree(bus);
397 return;
398 }
399
400 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
401 bus->state = MDIOBUS_RELEASED;
402
403 put_device(&bus->dev);
404}
405EXPORT_SYMBOL(mdiobus_free);
406
407/**
408 * mdiobus_scan - scan a bus for MDIO devices.
409 * @bus: mii_bus to scan
410 * @addr: address on bus to scan
411 *
412 * This function scans the MDIO bus, looking for devices which can be
413 * identified using a vendor/product ID in registers 2 and 3. Not all
414 * MDIO devices have such registers, but PHY devices typically
415 * do. Hence this function assumes anything found is a PHY, or can be
416 * treated as a PHY. Other MDIO devices, such as switches, will
417 * probably not be found during the scan.
418 */
419struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
420{
421 struct phy_device *phydev;
422 int err;
423
424 phydev = get_phy_device(bus, addr, false);
425 if (IS_ERR(phydev))
426 return phydev;
427
428 /*
429 * For DT, see if the auto-probed phy has a correspoding child
430 * in the bus node, and set the of_node pointer in this case.
431 */
432 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
433
434 err = phy_device_register(phydev);
435 if (err) {
436 phy_device_free(phydev);
437 return ERR_PTR(-ENODEV);
438 }
439
440 return phydev;
441}
442EXPORT_SYMBOL(mdiobus_scan);
443
444/**
445 * mdiobus_read_nested - Nested version of the mdiobus_read function
446 * @bus: the mii_bus struct
447 * @addr: the phy address
448 * @regnum: register number to read
449 *
450 * In case of nested MDIO bus access avoid lockdep false positives by
451 * using mutex_lock_nested().
452 *
453 * NOTE: MUST NOT be called from interrupt context,
454 * because the bus read/write functions may wait for an interrupt
455 * to conclude the operation.
456 */
457int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
458{
459 int retval;
460
461 BUG_ON(in_interrupt());
462
463 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
464 retval = bus->read(bus, addr, regnum);
465 mutex_unlock(&bus->mdio_lock);
466
467 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
468
469 return retval;
470}
471EXPORT_SYMBOL(mdiobus_read_nested);
472
473/**
474 * mdiobus_read - Convenience function for reading a given MII mgmt register
475 * @bus: the mii_bus struct
476 * @addr: the phy address
477 * @regnum: register number to read
478 *
479 * NOTE: MUST NOT be called from interrupt context,
480 * because the bus read/write functions may wait for an interrupt
481 * to conclude the operation.
482 */
483int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
484{
485 int retval;
486
487 BUG_ON(in_interrupt());
488
489 mutex_lock(&bus->mdio_lock);
490 retval = bus->read(bus, addr, regnum);
491 mutex_unlock(&bus->mdio_lock);
492
493 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
494
495 return retval;
496}
497EXPORT_SYMBOL(mdiobus_read);
498
499/**
500 * mdiobus_write_nested - Nested version of the mdiobus_write function
501 * @bus: the mii_bus struct
502 * @addr: the phy address
503 * @regnum: register number to write
504 * @val: value to write to @regnum
505 *
506 * In case of nested MDIO bus access avoid lockdep false positives by
507 * using mutex_lock_nested().
508 *
509 * NOTE: MUST NOT be called from interrupt context,
510 * because the bus read/write functions may wait for an interrupt
511 * to conclude the operation.
512 */
513int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
514{
515 int err;
516
517 BUG_ON(in_interrupt());
518
519 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
520 err = bus->write(bus, addr, regnum, val);
521 mutex_unlock(&bus->mdio_lock);
522
523 trace_mdio_access(bus, 0, addr, regnum, val, err);
524
525 return err;
526}
527EXPORT_SYMBOL(mdiobus_write_nested);
528
529/**
530 * mdiobus_write - Convenience function for writing a given MII mgmt register
531 * @bus: the mii_bus struct
532 * @addr: the phy address
533 * @regnum: register number to write
534 * @val: value to write to @regnum
535 *
536 * NOTE: MUST NOT be called from interrupt context,
537 * because the bus read/write functions may wait for an interrupt
538 * to conclude the operation.
539 */
540int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
541{
542 int err;
543
544 BUG_ON(in_interrupt());
545
546 mutex_lock(&bus->mdio_lock);
547 err = bus->write(bus, addr, regnum, val);
548 mutex_unlock(&bus->mdio_lock);
549
550 trace_mdio_access(bus, 0, addr, regnum, val, err);
551
552 return err;
553}
554EXPORT_SYMBOL(mdiobus_write);
555
556/**
557 * mdio_bus_match - determine if given MDIO driver supports the given
558 * MDIO device
559 * @dev: target MDIO device
560 * @drv: given MDIO driver
561 *
562 * Description: Given a MDIO device, and a MDIO driver, return 1 if
563 * the driver supports the device. Otherwise, return 0. This may
564 * require calling the devices own match function, since different classes
565 * of MDIO devices have different match criteria.
566 */
567static int mdio_bus_match(struct device *dev, struct device_driver *drv)
568{
569 struct mdio_device *mdio = to_mdio_device(dev);
570
571 if (of_driver_match_device(dev, drv))
572 return 1;
573
574 if (mdio->bus_match)
575 return mdio->bus_match(dev, drv);
576
577 return 0;
578}
579
580#ifdef CONFIG_PM
581static int mdio_bus_suspend(struct device *dev)
582{
583 struct mdio_device *mdio = to_mdio_device(dev);
584
585 if (mdio->pm_ops && mdio->pm_ops->suspend)
586 return mdio->pm_ops->suspend(dev);
587
588 return 0;
589}
590
591static int mdio_bus_resume(struct device *dev)
592{
593 struct mdio_device *mdio = to_mdio_device(dev);
594
595 if (mdio->pm_ops && mdio->pm_ops->resume)
596 return mdio->pm_ops->resume(dev);
597
598 return 0;
599}
600
601static int mdio_bus_restore(struct device *dev)
602{
603 struct mdio_device *mdio = to_mdio_device(dev);
604
605 if (mdio->pm_ops && mdio->pm_ops->restore)
606 return mdio->pm_ops->restore(dev);
607
608 return 0;
609}
610
611static const struct dev_pm_ops mdio_bus_pm_ops = {
612 .suspend = mdio_bus_suspend,
613 .resume = mdio_bus_resume,
614 .freeze = mdio_bus_suspend,
615 .thaw = mdio_bus_resume,
616 .restore = mdio_bus_restore,
617};
618
619#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
620
621#else
622
623#define MDIO_BUS_PM_OPS NULL
624
625#endif /* CONFIG_PM */
626
627struct bus_type mdio_bus_type = {
628 .name = "mdio_bus",
629 .match = mdio_bus_match,
630 .pm = MDIO_BUS_PM_OPS,
631};
632EXPORT_SYMBOL(mdio_bus_type);
633
634int __init mdio_bus_init(void)
635{
636 int ret;
637
638 ret = class_register(&mdio_bus_class);
639 if (!ret) {
640 ret = bus_register(&mdio_bus_type);
641 if (ret)
642 class_unregister(&mdio_bus_class);
643 }
644
645 return ret;
646}
647
648void mdio_bus_exit(void)
649{
650 class_unregister(&mdio_bus_class);
651 bus_unregister(&mdio_bus_type);
652}