Loading...
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// SPDX-License-Identifier: GPL-2.0+
2/* MDIO Bus interface
3 *
4 * Author: Andy Fleming
5 *
6 * Copyright (c) 2004 Freescale Semiconductor, Inc.
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <linux/unistd.h>
15#include <linux/slab.h>
16#include <linux/interrupt.h>
17#include <linux/init.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/gpio.h>
21#include <linux/gpio/consumer.h>
22#include <linux/of_device.h>
23#include <linux/of_mdio.h>
24#include <linux/of_gpio.h>
25#include <linux/netdevice.h>
26#include <linux/etherdevice.h>
27#include <linux/reset.h>
28#include <linux/skbuff.h>
29#include <linux/spinlock.h>
30#include <linux/mm.h>
31#include <linux/module.h>
32#include <linux/mii.h>
33#include <linux/ethtool.h>
34#include <linux/phy.h>
35#include <linux/io.h>
36#include <linux/uaccess.h>
37
38#define CREATE_TRACE_POINTS
39#include <trace/events/mdio.h>
40
41#include "mdio-boardinfo.h"
42
43static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
44{
45 int error;
46
47 /* Deassert the optional reset signal */
48 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
49 "reset", GPIOD_OUT_LOW);
50 error = PTR_ERR_OR_ZERO(mdiodev->reset_gpio);
51 if (error)
52 return error;
53
54 if (mdiodev->reset_gpio)
55 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
56
57 return 0;
58}
59
60static int mdiobus_register_reset(struct mdio_device *mdiodev)
61{
62 struct reset_control *reset = NULL;
63
64 if (mdiodev->dev.of_node)
65 reset = devm_reset_control_get_exclusive(&mdiodev->dev,
66 "phy");
67 if (IS_ERR(reset)) {
68 if (PTR_ERR(reset) == -ENOENT || PTR_ERR(reset) == -ENOTSUPP)
69 reset = NULL;
70 else
71 return PTR_ERR(reset);
72 }
73
74 mdiodev->reset_ctrl = reset;
75
76 return 0;
77}
78
79int mdiobus_register_device(struct mdio_device *mdiodev)
80{
81 int err;
82
83 if (mdiodev->bus->mdio_map[mdiodev->addr])
84 return -EBUSY;
85
86 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
87 err = mdiobus_register_gpiod(mdiodev);
88 if (err)
89 return err;
90
91 err = mdiobus_register_reset(mdiodev);
92 if (err)
93 return err;
94
95 /* Assert the reset signal */
96 mdio_device_reset(mdiodev, 1);
97 }
98
99 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
100
101 return 0;
102}
103EXPORT_SYMBOL(mdiobus_register_device);
104
105int mdiobus_unregister_device(struct mdio_device *mdiodev)
106{
107 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
108 return -EINVAL;
109
110 mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
111
112 return 0;
113}
114EXPORT_SYMBOL(mdiobus_unregister_device);
115
116struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
117{
118 struct mdio_device *mdiodev = bus->mdio_map[addr];
119
120 if (!mdiodev)
121 return NULL;
122
123 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
124 return NULL;
125
126 return container_of(mdiodev, struct phy_device, mdio);
127}
128EXPORT_SYMBOL(mdiobus_get_phy);
129
130bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
131{
132 return bus->mdio_map[addr];
133}
134EXPORT_SYMBOL(mdiobus_is_registered_device);
135
136/**
137 * mdiobus_alloc_size - allocate a mii_bus structure
138 * @size: extra amount of memory to allocate for private storage.
139 * If non-zero, then bus->priv is points to that memory.
140 *
141 * Description: called by a bus driver to allocate an mii_bus
142 * structure to fill in.
143 */
144struct mii_bus *mdiobus_alloc_size(size_t size)
145{
146 struct mii_bus *bus;
147 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
148 size_t alloc_size;
149 int i;
150
151 /* If we alloc extra space, it should be aligned */
152 if (size)
153 alloc_size = aligned_size + size;
154 else
155 alloc_size = sizeof(*bus);
156
157 bus = kzalloc(alloc_size, GFP_KERNEL);
158 if (!bus)
159 return NULL;
160
161 bus->state = MDIOBUS_ALLOCATED;
162 if (size)
163 bus->priv = (void *)bus + aligned_size;
164
165 /* Initialise the interrupts to polling */
166 for (i = 0; i < PHY_MAX_ADDR; i++)
167 bus->irq[i] = PHY_POLL;
168
169 return bus;
170}
171EXPORT_SYMBOL(mdiobus_alloc_size);
172
173static void _devm_mdiobus_free(struct device *dev, void *res)
174{
175 mdiobus_free(*(struct mii_bus **)res);
176}
177
178static int devm_mdiobus_match(struct device *dev, void *res, void *data)
179{
180 struct mii_bus **r = res;
181
182 if (WARN_ON(!r || !*r))
183 return 0;
184
185 return *r == data;
186}
187
188/**
189 * devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
190 * @dev: Device to allocate mii_bus for
191 * @sizeof_priv: Space to allocate for private structure.
192 *
193 * Managed mdiobus_alloc_size. mii_bus allocated with this function is
194 * automatically freed on driver detach.
195 *
196 * If an mii_bus allocated with this function needs to be freed separately,
197 * devm_mdiobus_free() must be used.
198 *
199 * RETURNS:
200 * Pointer to allocated mii_bus on success, NULL on failure.
201 */
202struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
203{
204 struct mii_bus **ptr, *bus;
205
206 ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
207 if (!ptr)
208 return NULL;
209
210 /* use raw alloc_dr for kmalloc caller tracing */
211 bus = mdiobus_alloc_size(sizeof_priv);
212 if (bus) {
213 *ptr = bus;
214 devres_add(dev, ptr);
215 } else {
216 devres_free(ptr);
217 }
218
219 return bus;
220}
221EXPORT_SYMBOL_GPL(devm_mdiobus_alloc_size);
222
223/**
224 * devm_mdiobus_free - Resource-managed mdiobus_free()
225 * @dev: Device this mii_bus belongs to
226 * @bus: the mii_bus associated with the device
227 *
228 * Free mii_bus allocated with devm_mdiobus_alloc_size().
229 */
230void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
231{
232 int rc;
233
234 rc = devres_release(dev, _devm_mdiobus_free,
235 devm_mdiobus_match, bus);
236 WARN_ON(rc);
237}
238EXPORT_SYMBOL_GPL(devm_mdiobus_free);
239
240/**
241 * mdiobus_release - mii_bus device release callback
242 * @d: the target struct device that contains the mii_bus
243 *
244 * Description: called when the last reference to an mii_bus is
245 * dropped, to free the underlying memory.
246 */
247static void mdiobus_release(struct device *d)
248{
249 struct mii_bus *bus = to_mii_bus(d);
250 BUG_ON(bus->state != MDIOBUS_RELEASED &&
251 /* for compatibility with error handling in drivers */
252 bus->state != MDIOBUS_ALLOCATED);
253 kfree(bus);
254}
255
256static struct class mdio_bus_class = {
257 .name = "mdio_bus",
258 .dev_release = mdiobus_release,
259};
260
261#if IS_ENABLED(CONFIG_OF_MDIO)
262/**
263 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
264 * @mdio_bus_np: Pointer to the mii_bus.
265 *
266 * Returns a reference to the mii_bus, or NULL if none found. The
267 * embedded struct device will have its reference count incremented,
268 * and this must be put once the bus is finished with.
269 *
270 * Because the association of a device_node and mii_bus is made via
271 * of_mdiobus_register(), the mii_bus cannot be found before it is
272 * registered with of_mdiobus_register().
273 *
274 */
275struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
276{
277 struct device *d;
278
279 if (!mdio_bus_np)
280 return NULL;
281
282 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
283 return d ? to_mii_bus(d) : NULL;
284}
285EXPORT_SYMBOL(of_mdio_find_bus);
286
287/* Walk the list of subnodes of a mdio bus and look for a node that
288 * matches the mdio device's address with its 'reg' property. If
289 * found, set the of_node pointer for the mdio device. This allows
290 * auto-probed phy devices to be supplied with information passed in
291 * via DT.
292 */
293static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
294 struct mdio_device *mdiodev)
295{
296 struct device *dev = &mdiodev->dev;
297 struct device_node *child;
298
299 if (dev->of_node || !bus->dev.of_node)
300 return;
301
302 for_each_available_child_of_node(bus->dev.of_node, child) {
303 int addr;
304
305 addr = of_mdio_parse_addr(dev, child);
306 if (addr < 0)
307 continue;
308
309 if (addr == mdiodev->addr) {
310 dev->of_node = child;
311 dev->fwnode = of_fwnode_handle(child);
312 return;
313 }
314 }
315}
316#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
317static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
318 struct mdio_device *mdiodev)
319{
320}
321#endif
322
323/**
324 * mdiobus_create_device_from_board_info - create a full MDIO device given
325 * a mdio_board_info structure
326 * @bus: MDIO bus to create the devices on
327 * @bi: mdio_board_info structure describing the devices
328 *
329 * Returns 0 on success or < 0 on error.
330 */
331static int mdiobus_create_device(struct mii_bus *bus,
332 struct mdio_board_info *bi)
333{
334 struct mdio_device *mdiodev;
335 int ret = 0;
336
337 mdiodev = mdio_device_create(bus, bi->mdio_addr);
338 if (IS_ERR(mdiodev))
339 return -ENODEV;
340
341 strncpy(mdiodev->modalias, bi->modalias,
342 sizeof(mdiodev->modalias));
343 mdiodev->bus_match = mdio_device_bus_match;
344 mdiodev->dev.platform_data = (void *)bi->platform_data;
345
346 ret = mdio_device_register(mdiodev);
347 if (ret)
348 mdio_device_free(mdiodev);
349
350 return ret;
351}
352
353/**
354 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
355 * @bus: target mii_bus
356 * @owner: module containing bus accessor functions
357 *
358 * Description: Called by a bus driver to bring up all the PHYs
359 * on a given bus, and attach them to the bus. Drivers should use
360 * mdiobus_register() rather than __mdiobus_register() unless they
361 * need to pass a specific owner module. MDIO devices which are not
362 * PHYs will not be brought up by this function. They are expected to
363 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
364 *
365 * Returns 0 on success or < 0 on error.
366 */
367int __mdiobus_register(struct mii_bus *bus, struct module *owner)
368{
369 struct mdio_device *mdiodev;
370 int i, err;
371 struct gpio_desc *gpiod;
372
373 if (NULL == bus || NULL == bus->name ||
374 NULL == bus->read || NULL == bus->write)
375 return -EINVAL;
376
377 BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
378 bus->state != MDIOBUS_UNREGISTERED);
379
380 bus->owner = owner;
381 bus->dev.parent = bus->parent;
382 bus->dev.class = &mdio_bus_class;
383 bus->dev.groups = NULL;
384 dev_set_name(&bus->dev, "%s", bus->id);
385
386 err = device_register(&bus->dev);
387 if (err) {
388 pr_err("mii_bus %s failed to register\n", bus->id);
389 return -EINVAL;
390 }
391
392 mutex_init(&bus->mdio_lock);
393
394 /* de-assert bus level PHY GPIO reset */
395 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_LOW);
396 if (IS_ERR(gpiod)) {
397 dev_err(&bus->dev, "mii_bus %s couldn't get reset GPIO\n",
398 bus->id);
399 device_del(&bus->dev);
400 return PTR_ERR(gpiod);
401 } else if (gpiod) {
402 bus->reset_gpiod = gpiod;
403
404 gpiod_set_value_cansleep(gpiod, 1);
405 udelay(bus->reset_delay_us);
406 gpiod_set_value_cansleep(gpiod, 0);
407 }
408
409 if (bus->reset)
410 bus->reset(bus);
411
412 for (i = 0; i < PHY_MAX_ADDR; i++) {
413 if ((bus->phy_mask & (1 << i)) == 0) {
414 struct phy_device *phydev;
415
416 phydev = mdiobus_scan(bus, i);
417 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {
418 err = PTR_ERR(phydev);
419 goto error;
420 }
421 }
422 }
423
424 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
425
426 bus->state = MDIOBUS_REGISTERED;
427 pr_info("%s: probed\n", bus->name);
428 return 0;
429
430error:
431 while (--i >= 0) {
432 mdiodev = bus->mdio_map[i];
433 if (!mdiodev)
434 continue;
435
436 mdiodev->device_remove(mdiodev);
437 mdiodev->device_free(mdiodev);
438 }
439
440 /* Put PHYs in RESET to save power */
441 if (bus->reset_gpiod)
442 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
443
444 device_del(&bus->dev);
445 return err;
446}
447EXPORT_SYMBOL(__mdiobus_register);
448
449void mdiobus_unregister(struct mii_bus *bus)
450{
451 struct mdio_device *mdiodev;
452 int i;
453
454 BUG_ON(bus->state != MDIOBUS_REGISTERED);
455 bus->state = MDIOBUS_UNREGISTERED;
456
457 for (i = 0; i < PHY_MAX_ADDR; i++) {
458 mdiodev = bus->mdio_map[i];
459 if (!mdiodev)
460 continue;
461
462 if (mdiodev->reset_gpio)
463 gpiod_put(mdiodev->reset_gpio);
464
465 mdiodev->device_remove(mdiodev);
466 mdiodev->device_free(mdiodev);
467 }
468
469 /* Put PHYs in RESET to save power */
470 if (bus->reset_gpiod)
471 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
472
473 device_del(&bus->dev);
474}
475EXPORT_SYMBOL(mdiobus_unregister);
476
477/**
478 * mdiobus_free - free a struct mii_bus
479 * @bus: mii_bus to free
480 *
481 * This function releases the reference to the underlying device
482 * object in the mii_bus. If this is the last reference, the mii_bus
483 * will be freed.
484 */
485void mdiobus_free(struct mii_bus *bus)
486{
487 /* For compatibility with error handling in drivers. */
488 if (bus->state == MDIOBUS_ALLOCATED) {
489 kfree(bus);
490 return;
491 }
492
493 BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
494 bus->state = MDIOBUS_RELEASED;
495
496 put_device(&bus->dev);
497}
498EXPORT_SYMBOL(mdiobus_free);
499
500/**
501 * mdiobus_scan - scan a bus for MDIO devices.
502 * @bus: mii_bus to scan
503 * @addr: address on bus to scan
504 *
505 * This function scans the MDIO bus, looking for devices which can be
506 * identified using a vendor/product ID in registers 2 and 3. Not all
507 * MDIO devices have such registers, but PHY devices typically
508 * do. Hence this function assumes anything found is a PHY, or can be
509 * treated as a PHY. Other MDIO devices, such as switches, will
510 * probably not be found during the scan.
511 */
512struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
513{
514 struct phy_device *phydev;
515 int err;
516
517 phydev = get_phy_device(bus, addr, false);
518 if (IS_ERR(phydev))
519 return phydev;
520
521 /*
522 * For DT, see if the auto-probed phy has a correspoding child
523 * in the bus node, and set the of_node pointer in this case.
524 */
525 of_mdiobus_link_mdiodev(bus, &phydev->mdio);
526
527 err = phy_device_register(phydev);
528 if (err) {
529 phy_device_free(phydev);
530 return ERR_PTR(-ENODEV);
531 }
532
533 return phydev;
534}
535EXPORT_SYMBOL(mdiobus_scan);
536
537/**
538 * __mdiobus_read - Unlocked version of the mdiobus_read function
539 * @bus: the mii_bus struct
540 * @addr: the phy address
541 * @regnum: register number to read
542 *
543 * Read a MDIO bus register. Caller must hold the mdio bus lock.
544 *
545 * NOTE: MUST NOT be called from interrupt context.
546 */
547int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
548{
549 int retval;
550
551 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
552
553 retval = bus->read(bus, addr, regnum);
554
555 trace_mdio_access(bus, 1, addr, regnum, retval, retval);
556
557 return retval;
558}
559EXPORT_SYMBOL(__mdiobus_read);
560
561/**
562 * __mdiobus_write - Unlocked version of the mdiobus_write function
563 * @bus: the mii_bus struct
564 * @addr: the phy address
565 * @regnum: register number to write
566 * @val: value to write to @regnum
567 *
568 * Write a MDIO bus register. Caller must hold the mdio bus lock.
569 *
570 * NOTE: MUST NOT be called from interrupt context.
571 */
572int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
573{
574 int err;
575
576 WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
577
578 err = bus->write(bus, addr, regnum, val);
579
580 trace_mdio_access(bus, 0, addr, regnum, val, err);
581
582 return err;
583}
584EXPORT_SYMBOL(__mdiobus_write);
585
586/**
587 * mdiobus_read_nested - Nested version of the mdiobus_read function
588 * @bus: the mii_bus struct
589 * @addr: the phy address
590 * @regnum: register number to read
591 *
592 * In case of nested MDIO bus access avoid lockdep false positives by
593 * using mutex_lock_nested().
594 *
595 * NOTE: MUST NOT be called from interrupt context,
596 * because the bus read/write functions may wait for an interrupt
597 * to conclude the operation.
598 */
599int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
600{
601 int retval;
602
603 BUG_ON(in_interrupt());
604
605 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
606 retval = __mdiobus_read(bus, addr, regnum);
607 mutex_unlock(&bus->mdio_lock);
608
609 return retval;
610}
611EXPORT_SYMBOL(mdiobus_read_nested);
612
613/**
614 * mdiobus_read - Convenience function for reading a given MII mgmt register
615 * @bus: the mii_bus struct
616 * @addr: the phy address
617 * @regnum: register number to read
618 *
619 * NOTE: MUST NOT be called from interrupt context,
620 * because the bus read/write functions may wait for an interrupt
621 * to conclude the operation.
622 */
623int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
624{
625 int retval;
626
627 BUG_ON(in_interrupt());
628
629 mutex_lock(&bus->mdio_lock);
630 retval = __mdiobus_read(bus, addr, regnum);
631 mutex_unlock(&bus->mdio_lock);
632
633 return retval;
634}
635EXPORT_SYMBOL(mdiobus_read);
636
637/**
638 * mdiobus_write_nested - Nested version of the mdiobus_write function
639 * @bus: the mii_bus struct
640 * @addr: the phy address
641 * @regnum: register number to write
642 * @val: value to write to @regnum
643 *
644 * In case of nested MDIO bus access avoid lockdep false positives by
645 * using mutex_lock_nested().
646 *
647 * NOTE: MUST NOT be called from interrupt context,
648 * because the bus read/write functions may wait for an interrupt
649 * to conclude the operation.
650 */
651int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
652{
653 int err;
654
655 BUG_ON(in_interrupt());
656
657 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
658 err = __mdiobus_write(bus, addr, regnum, val);
659 mutex_unlock(&bus->mdio_lock);
660
661 return err;
662}
663EXPORT_SYMBOL(mdiobus_write_nested);
664
665/**
666 * mdiobus_write - Convenience function for writing a given MII mgmt register
667 * @bus: the mii_bus struct
668 * @addr: the phy address
669 * @regnum: register number to write
670 * @val: value to write to @regnum
671 *
672 * NOTE: MUST NOT be called from interrupt context,
673 * because the bus read/write functions may wait for an interrupt
674 * to conclude the operation.
675 */
676int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
677{
678 int err;
679
680 BUG_ON(in_interrupt());
681
682 mutex_lock(&bus->mdio_lock);
683 err = __mdiobus_write(bus, addr, regnum, val);
684 mutex_unlock(&bus->mdio_lock);
685
686 return err;
687}
688EXPORT_SYMBOL(mdiobus_write);
689
690/**
691 * mdio_bus_match - determine if given MDIO driver supports the given
692 * MDIO device
693 * @dev: target MDIO device
694 * @drv: given MDIO driver
695 *
696 * Description: Given a MDIO device, and a MDIO driver, return 1 if
697 * the driver supports the device. Otherwise, return 0. This may
698 * require calling the devices own match function, since different classes
699 * of MDIO devices have different match criteria.
700 */
701static int mdio_bus_match(struct device *dev, struct device_driver *drv)
702{
703 struct mdio_device *mdio = to_mdio_device(dev);
704
705 if (of_driver_match_device(dev, drv))
706 return 1;
707
708 if (mdio->bus_match)
709 return mdio->bus_match(dev, drv);
710
711 return 0;
712}
713
714static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
715{
716 int rc;
717
718 /* Some devices have extra OF data and an OF-style MODALIAS */
719 rc = of_device_uevent_modalias(dev, env);
720 if (rc != -ENODEV)
721 return rc;
722
723 return 0;
724}
725
726struct bus_type mdio_bus_type = {
727 .name = "mdio_bus",
728 .match = mdio_bus_match,
729 .uevent = mdio_uevent,
730};
731EXPORT_SYMBOL(mdio_bus_type);
732
733int __init mdio_bus_init(void)
734{
735 int ret;
736
737 ret = class_register(&mdio_bus_class);
738 if (!ret) {
739 ret = bus_register(&mdio_bus_type);
740 if (ret)
741 class_unregister(&mdio_bus_class);
742 }
743
744 return ret;
745}
746EXPORT_SYMBOL_GPL(mdio_bus_init);
747
748#if IS_ENABLED(CONFIG_PHYLIB)
749void mdio_bus_exit(void)
750{
751 class_unregister(&mdio_bus_class);
752 bus_unregister(&mdio_bus_type);
753}
754EXPORT_SYMBOL_GPL(mdio_bus_exit);
755#else
756module_init(mdio_bus_init);
757/* no module_exit, intentional */
758MODULE_LICENSE("GPL");
759MODULE_DESCRIPTION("MDIO bus/device layer");
760#endif