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/delay.h>
12 #include <linux/device.h>
13 #include <linux/errno.h>
14 #include <linux/etherdevice.h>
15 #include <linux/ethtool.h>
16 #include <linux/gpio.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/micrel_phy.h>
23 #include <linux/mii.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/netdevice.h>
27 #include <linux/of_device.h>
28 #include <linux/of_gpio.h>
29 #include <linux/of_mdio.h>
30 #include <linux/phy.h>
31 #include <linux/reset.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/string.h>
36 #include <linux/uaccess.h>
37 #include <linux/unistd.h>
38 
39 #define CREATE_TRACE_POINTS
40 #include <trace/events/mdio.h>
41 
42 #include "mdio-boardinfo.h"
43 
mdiobus_register_gpiod(struct mdio_device * mdiodev)44 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
45 {
46 	/* Deassert the optional reset signal */
47 	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
48 						 "reset", GPIOD_OUT_LOW);
49 	if (IS_ERR(mdiodev->reset_gpio))
50 		return PTR_ERR(mdiodev->reset_gpio);
51 
52 	if (mdiodev->reset_gpio)
53 		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");
54 
55 	return 0;
56 }
57 
mdiobus_register_reset(struct mdio_device * mdiodev)58 static int mdiobus_register_reset(struct mdio_device *mdiodev)
59 {
60 	struct reset_control *reset;
61 
62 	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
63 	if (IS_ERR(reset))
64 		return PTR_ERR(reset);
65 
66 	mdiodev->reset_ctrl = reset;
67 
68 	return 0;
69 }
70 
mdiobus_register_device(struct mdio_device * mdiodev)71 int mdiobus_register_device(struct mdio_device *mdiodev)
72 {
73 	int err;
74 
75 	if (mdiodev->bus->mdio_map[mdiodev->addr])
76 		return -EBUSY;
77 
78 	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
79 		err = mdiobus_register_gpiod(mdiodev);
80 		if (err)
81 			return err;
82 
83 		err = mdiobus_register_reset(mdiodev);
84 		if (err)
85 			return err;
86 
87 		/* Assert the reset signal */
88 		mdio_device_reset(mdiodev, 1);
89 	}
90 
91 	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
92 
93 	return 0;
94 }
95 EXPORT_SYMBOL(mdiobus_register_device);
96 
mdiobus_unregister_device(struct mdio_device * mdiodev)97 int mdiobus_unregister_device(struct mdio_device *mdiodev)
98 {
99 	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
100 		return -EINVAL;
101 
102 	reset_control_put(mdiodev->reset_ctrl);
103 
104 	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
105 
106 	return 0;
107 }
108 EXPORT_SYMBOL(mdiobus_unregister_device);
109 
mdiobus_find_device(struct mii_bus * bus,int addr)110 static struct mdio_device *mdiobus_find_device(struct mii_bus *bus, int addr)
111 {
112 	bool addr_valid = addr >= 0 && addr < ARRAY_SIZE(bus->mdio_map);
113 
114 	if (WARN_ONCE(!addr_valid, "addr %d out of range\n", addr))
115 		return NULL;
116 
117 	return bus->mdio_map[addr];
118 }
119 
mdiobus_get_phy(struct mii_bus * bus,int addr)120 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
121 {
122 	struct mdio_device *mdiodev;
123 
124 	mdiodev = mdiobus_find_device(bus, addr);
125 	if (!mdiodev)
126 		return NULL;
127 
128 	if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
129 		return NULL;
130 
131 	return container_of(mdiodev, struct phy_device, mdio);
132 }
133 EXPORT_SYMBOL(mdiobus_get_phy);
134 
mdiobus_is_registered_device(struct mii_bus * bus,int addr)135 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
136 {
137 	return mdiobus_find_device(bus, addr) != NULL;
138 }
139 EXPORT_SYMBOL(mdiobus_is_registered_device);
140 
141 /**
142  * mdiobus_alloc_size - allocate a mii_bus structure
143  * @size: extra amount of memory to allocate for private storage.
144  * If non-zero, then bus->priv is points to that memory.
145  *
146  * Description: called by a bus driver to allocate an mii_bus
147  * structure to fill in.
148  */
mdiobus_alloc_size(size_t size)149 struct mii_bus *mdiobus_alloc_size(size_t size)
150 {
151 	struct mii_bus *bus;
152 	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
153 	size_t alloc_size;
154 	int i;
155 
156 	/* If we alloc extra space, it should be aligned */
157 	if (size)
158 		alloc_size = aligned_size + size;
159 	else
160 		alloc_size = sizeof(*bus);
161 
162 	bus = kzalloc(alloc_size, GFP_KERNEL);
163 	if (!bus)
164 		return NULL;
165 
166 	bus->state = MDIOBUS_ALLOCATED;
167 	if (size)
168 		bus->priv = (void *)bus + aligned_size;
169 
170 	/* Initialise the interrupts to polling and 64-bit seqcounts */
171 	for (i = 0; i < PHY_MAX_ADDR; i++) {
172 		bus->irq[i] = PHY_POLL;
173 		u64_stats_init(&bus->stats[i].syncp);
174 	}
175 
176 	return bus;
177 }
178 EXPORT_SYMBOL(mdiobus_alloc_size);
179 
180 /**
181  * mdiobus_release - mii_bus device release callback
182  * @d: the target struct device that contains the mii_bus
183  *
184  * Description: called when the last reference to an mii_bus is
185  * dropped, to free the underlying memory.
186  */
mdiobus_release(struct device * d)187 static void mdiobus_release(struct device *d)
188 {
189 	struct mii_bus *bus = to_mii_bus(d);
190 
191 	WARN(bus->state != MDIOBUS_RELEASED &&
192 	     /* for compatibility with error handling in drivers */
193 	     bus->state != MDIOBUS_ALLOCATED,
194 	     "%s: not in RELEASED or ALLOCATED state\n",
195 	     bus->id);
196 	kfree(bus);
197 }
198 
199 struct mdio_bus_stat_attr {
200 	int addr;
201 	unsigned int field_offset;
202 };
203 
mdio_bus_get_stat(struct mdio_bus_stats * s,unsigned int offset)204 static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
205 {
206 	const char *p = (const char *)s + offset;
207 	unsigned int start;
208 	u64 val = 0;
209 
210 	do {
211 		start = u64_stats_fetch_begin(&s->syncp);
212 		val = u64_stats_read((const u64_stats_t *)p);
213 	} while (u64_stats_fetch_retry(&s->syncp, start));
214 
215 	return val;
216 }
217 
mdio_bus_get_global_stat(struct mii_bus * bus,unsigned int offset)218 static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
219 {
220 	unsigned int i;
221 	u64 val = 0;
222 
223 	for (i = 0; i < PHY_MAX_ADDR; i++)
224 		val += mdio_bus_get_stat(&bus->stats[i], offset);
225 
226 	return val;
227 }
228 
mdio_bus_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)229 static ssize_t mdio_bus_stat_field_show(struct device *dev,
230 					struct device_attribute *attr,
231 					char *buf)
232 {
233 	struct mii_bus *bus = to_mii_bus(dev);
234 	struct mdio_bus_stat_attr *sattr;
235 	struct dev_ext_attribute *eattr;
236 	u64 val;
237 
238 	eattr = container_of(attr, struct dev_ext_attribute, attr);
239 	sattr = eattr->var;
240 
241 	if (sattr->addr < 0)
242 		val = mdio_bus_get_global_stat(bus, sattr->field_offset);
243 	else
244 		val = mdio_bus_get_stat(&bus->stats[sattr->addr],
245 					sattr->field_offset);
246 
247 	return sysfs_emit(buf, "%llu\n", val);
248 }
249 
mdio_bus_device_stat_field_show(struct device * dev,struct device_attribute * attr,char * buf)250 static ssize_t mdio_bus_device_stat_field_show(struct device *dev,
251 					       struct device_attribute *attr,
252 					       char *buf)
253 {
254 	struct mdio_device *mdiodev = to_mdio_device(dev);
255 	struct mii_bus *bus = mdiodev->bus;
256 	struct mdio_bus_stat_attr *sattr;
257 	struct dev_ext_attribute *eattr;
258 	int addr = mdiodev->addr;
259 	u64 val;
260 
261 	eattr = container_of(attr, struct dev_ext_attribute, attr);
262 	sattr = eattr->var;
263 
264 	val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset);
265 
266 	return sysfs_emit(buf, "%llu\n", val);
267 }
268 
269 #define MDIO_BUS_STATS_ATTR_DECL(field, file)				\
270 static struct dev_ext_attribute dev_attr_mdio_bus_##field = {		\
271 	.attr = { .attr = { .name = file, .mode = 0444 },		\
272 		     .show = mdio_bus_stat_field_show,			\
273 	},								\
274 	.var = &((struct mdio_bus_stat_attr) {				\
275 		-1, offsetof(struct mdio_bus_stats, field)		\
276 	}),								\
277 };									\
278 static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = {	\
279 	.attr = { .attr = { .name = file, .mode = 0444 },		\
280 		     .show = mdio_bus_device_stat_field_show,		\
281 	},								\
282 	.var = &((struct mdio_bus_stat_attr) {				\
283 		-1, offsetof(struct mdio_bus_stats, field)		\
284 	}),								\
285 };
286 
287 #define MDIO_BUS_STATS_ATTR(field)					\
288 	MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field))
289 
290 MDIO_BUS_STATS_ATTR(transfers);
291 MDIO_BUS_STATS_ATTR(errors);
292 MDIO_BUS_STATS_ATTR(writes);
293 MDIO_BUS_STATS_ATTR(reads);
294 
295 #define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file)		\
296 static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \
297 	.attr = { .attr = { .name = file, .mode = 0444 },		\
298 		     .show = mdio_bus_stat_field_show,			\
299 	},								\
300 	.var = &((struct mdio_bus_stat_attr) {				\
301 		addr, offsetof(struct mdio_bus_stats, field)		\
302 	}),								\
303 }
304 
305 #define MDIO_BUS_STATS_ADDR_ATTR(field, addr)				\
306 	MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr,			\
307 				 __stringify(field) "_" __stringify(addr))
308 
309 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr)			\
310 	MDIO_BUS_STATS_ADDR_ATTR(transfers, addr);			\
311 	MDIO_BUS_STATS_ADDR_ATTR(errors, addr);				\
312 	MDIO_BUS_STATS_ADDR_ATTR(writes, addr);				\
313 	MDIO_BUS_STATS_ADDR_ATTR(reads, addr)				\
314 
315 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0);
316 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1);
317 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2);
318 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3);
319 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4);
320 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5);
321 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6);
322 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7);
323 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8);
324 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9);
325 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10);
326 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11);
327 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12);
328 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13);
329 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14);
330 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15);
331 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16);
332 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17);
333 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18);
334 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19);
335 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20);
336 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21);
337 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22);
338 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23);
339 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24);
340 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25);
341 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26);
342 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27);
343 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28);
344 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29);
345 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30);
346 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31);
347 
348 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr)				\
349 	&dev_attr_mdio_bus_addr_transfers_##addr.attr.attr,		\
350 	&dev_attr_mdio_bus_addr_errors_##addr.attr.attr,		\
351 	&dev_attr_mdio_bus_addr_writes_##addr.attr.attr,		\
352 	&dev_attr_mdio_bus_addr_reads_##addr.attr.attr			\
353 
354 static struct attribute *mdio_bus_statistics_attrs[] = {
355 	&dev_attr_mdio_bus_transfers.attr.attr,
356 	&dev_attr_mdio_bus_errors.attr.attr,
357 	&dev_attr_mdio_bus_writes.attr.attr,
358 	&dev_attr_mdio_bus_reads.attr.attr,
359 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(0),
360 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(1),
361 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(2),
362 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(3),
363 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(4),
364 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(5),
365 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(6),
366 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(7),
367 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(8),
368 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(9),
369 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(10),
370 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(11),
371 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(12),
372 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(13),
373 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(14),
374 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(15),
375 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(16),
376 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(17),
377 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(18),
378 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(19),
379 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(20),
380 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(21),
381 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(22),
382 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(23),
383 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(24),
384 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(25),
385 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(26),
386 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(27),
387 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(28),
388 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(29),
389 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(30),
390 	MDIO_BUS_STATS_ADDR_ATTR_GROUP(31),
391 	NULL,
392 };
393 
394 static const struct attribute_group mdio_bus_statistics_group = {
395 	.name	= "statistics",
396 	.attrs	= mdio_bus_statistics_attrs,
397 };
398 
399 static const struct attribute_group *mdio_bus_groups[] = {
400 	&mdio_bus_statistics_group,
401 	NULL,
402 };
403 
404 static struct class mdio_bus_class = {
405 	.name		= "mdio_bus",
406 	.dev_release	= mdiobus_release,
407 	.dev_groups	= mdio_bus_groups,
408 };
409 
410 /**
411  * mdio_find_bus - Given the name of a mdiobus, find the mii_bus.
412  * @mdio_name: The name of a mdiobus.
413  *
414  * Returns a reference to the mii_bus, or NULL if none found.  The
415  * embedded struct device will have its reference count incremented,
416  * and this must be put_deviced'ed once the bus is finished with.
417  */
mdio_find_bus(const char * mdio_name)418 struct mii_bus *mdio_find_bus(const char *mdio_name)
419 {
420 	struct device *d;
421 
422 	d = class_find_device_by_name(&mdio_bus_class, mdio_name);
423 	return d ? to_mii_bus(d) : NULL;
424 }
425 EXPORT_SYMBOL(mdio_find_bus);
426 
427 #if IS_ENABLED(CONFIG_OF_MDIO)
428 /**
429  * of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
430  * @mdio_bus_np: Pointer to the mii_bus.
431  *
432  * Returns a reference to the mii_bus, or NULL if none found.  The
433  * embedded struct device will have its reference count incremented,
434  * and this must be put once the bus is finished with.
435  *
436  * Because the association of a device_node and mii_bus is made via
437  * of_mdiobus_register(), the mii_bus cannot be found before it is
438  * registered with of_mdiobus_register().
439  *
440  */
of_mdio_find_bus(struct device_node * mdio_bus_np)441 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
442 {
443 	struct device *d;
444 
445 	if (!mdio_bus_np)
446 		return NULL;
447 
448 	d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np);
449 	return d ? to_mii_bus(d) : NULL;
450 }
451 EXPORT_SYMBOL(of_mdio_find_bus);
452 
453 /* Walk the list of subnodes of a mdio bus and look for a node that
454  * matches the mdio device's address with its 'reg' property. If
455  * found, set the of_node pointer for the mdio device. This allows
456  * auto-probed phy devices to be supplied with information passed in
457  * via DT.
458  */
of_mdiobus_link_mdiodev(struct mii_bus * bus,struct mdio_device * mdiodev)459 static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
460 				    struct mdio_device *mdiodev)
461 {
462 	struct device *dev = &mdiodev->dev;
463 	struct device_node *child;
464 
465 	if (dev->of_node || !bus->dev.of_node)
466 		return;
467 
468 	for_each_available_child_of_node(bus->dev.of_node, child) {
469 		int addr;
470 
471 		addr = of_mdio_parse_addr(dev, child);
472 		if (addr < 0)
473 			continue;
474 
475 		if (addr == mdiodev->addr) {
476 			device_set_node(dev, of_fwnode_handle(child));
477 			/* The refcount on "child" is passed to the mdio
478 			 * device. Do _not_ use of_node_put(child) here.
479 			 */
480 			return;
481 		}
482 	}
483 }
484 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */
of_mdiobus_link_mdiodev(struct mii_bus * mdio,struct mdio_device * mdiodev)485 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
486 					   struct mdio_device *mdiodev)
487 {
488 }
489 #endif
490 
491 /**
492  * mdiobus_create_device - create a full MDIO device given
493  * a mdio_board_info structure
494  * @bus: MDIO bus to create the devices on
495  * @bi: mdio_board_info structure describing the devices
496  *
497  * Returns 0 on success or < 0 on error.
498  */
mdiobus_create_device(struct mii_bus * bus,struct mdio_board_info * bi)499 static int mdiobus_create_device(struct mii_bus *bus,
500 				 struct mdio_board_info *bi)
501 {
502 	struct mdio_device *mdiodev;
503 	int ret = 0;
504 
505 	mdiodev = mdio_device_create(bus, bi->mdio_addr);
506 	if (IS_ERR(mdiodev))
507 		return -ENODEV;
508 
509 	strncpy(mdiodev->modalias, bi->modalias,
510 		sizeof(mdiodev->modalias));
511 	mdiodev->bus_match = mdio_device_bus_match;
512 	mdiodev->dev.platform_data = (void *)bi->platform_data;
513 
514 	ret = mdio_device_register(mdiodev);
515 	if (ret)
516 		mdio_device_free(mdiodev);
517 
518 	return ret;
519 }
520 
mdiobus_scan(struct mii_bus * bus,int addr,bool c45)521 static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
522 {
523 	struct phy_device *phydev = ERR_PTR(-ENODEV);
524 	int err;
525 
526 	phydev = get_phy_device(bus, addr, c45);
527 	if (IS_ERR(phydev))
528 		return phydev;
529 
530 	/* For DT, see if the auto-probed phy has a corresponding child
531 	 * in the bus node, and set the of_node pointer in this case.
532 	 */
533 	of_mdiobus_link_mdiodev(bus, &phydev->mdio);
534 
535 	err = phy_device_register(phydev);
536 	if (err) {
537 		phy_device_free(phydev);
538 		return ERR_PTR(-ENODEV);
539 	}
540 
541 	return phydev;
542 }
543 
544 /**
545  * mdiobus_scan_c22 - scan one address on a bus for C22 MDIO devices.
546  * @bus: mii_bus to scan
547  * @addr: address on bus to scan
548  *
549  * This function scans one address on the MDIO bus, looking for
550  * devices which can be identified using a vendor/product ID in
551  * registers 2 and 3. Not all MDIO devices have such registers, but
552  * PHY devices typically do. Hence this function assumes anything
553  * found is a PHY, or can be treated as a PHY. Other MDIO devices,
554  * such as switches, will probably not be found during the scan.
555  */
mdiobus_scan_c22(struct mii_bus * bus,int addr)556 struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr)
557 {
558 	return mdiobus_scan(bus, addr, false);
559 }
560 EXPORT_SYMBOL(mdiobus_scan_c22);
561 
562 /**
563  * mdiobus_scan_c45 - scan one address on a bus for C45 MDIO devices.
564  * @bus: mii_bus to scan
565  * @addr: address on bus to scan
566  *
567  * This function scans one address on the MDIO bus, looking for
568  * devices which can be identified using a vendor/product ID in
569  * registers 2 and 3. Not all MDIO devices have such registers, but
570  * PHY devices typically do. Hence this function assumes anything
571  * found is a PHY, or can be treated as a PHY. Other MDIO devices,
572  * such as switches, will probably not be found during the scan.
573  */
mdiobus_scan_c45(struct mii_bus * bus,int addr)574 static struct phy_device *mdiobus_scan_c45(struct mii_bus *bus, int addr)
575 {
576 	return mdiobus_scan(bus, addr, true);
577 }
578 
mdiobus_scan_bus_c22(struct mii_bus * bus)579 static int mdiobus_scan_bus_c22(struct mii_bus *bus)
580 {
581 	int i;
582 
583 	for (i = 0; i < PHY_MAX_ADDR; i++) {
584 		if ((bus->phy_mask & BIT(i)) == 0) {
585 			struct phy_device *phydev;
586 
587 			phydev = mdiobus_scan_c22(bus, i);
588 			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
589 				return PTR_ERR(phydev);
590 		}
591 	}
592 	return 0;
593 }
594 
mdiobus_scan_bus_c45(struct mii_bus * bus)595 static int mdiobus_scan_bus_c45(struct mii_bus *bus)
596 {
597 	int i;
598 
599 	for (i = 0; i < PHY_MAX_ADDR; i++) {
600 		if ((bus->phy_mask & BIT(i)) == 0) {
601 			struct phy_device *phydev;
602 
603 			/* Don't scan C45 if we already have a C22 device */
604 			if (bus->mdio_map[i])
605 				continue;
606 
607 			phydev = mdiobus_scan_c45(bus, i);
608 			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
609 				return PTR_ERR(phydev);
610 		}
611 	}
612 	return 0;
613 }
614 
615 /* There are some C22 PHYs which do bad things when where is a C45
616  * transaction on the bus, like accepting a read themselves, and
617  * stomping over the true devices reply, to performing a write to
618  * themselves which was intended for another device. Now that C22
619  * devices have been found, see if any of them are bad for C45, and if we
620  * should skip the C45 scan.
621  */
mdiobus_prevent_c45_scan(struct mii_bus * bus)622 static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
623 {
624 	int i;
625 
626 	for (i = 0; i < PHY_MAX_ADDR; i++) {
627 		struct phy_device *phydev;
628 		u32 oui;
629 
630 		phydev = mdiobus_get_phy(bus, i);
631 		if (!phydev)
632 			continue;
633 		oui = phydev->phy_id >> 10;
634 
635 		if (oui == MICREL_OUI)
636 			return true;
637 	}
638 	return false;
639 }
640 
641 /**
642  * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
643  * @bus: target mii_bus
644  * @owner: module containing bus accessor functions
645  *
646  * Description: Called by a bus driver to bring up all the PHYs
647  *   on a given bus, and attach them to the bus. Drivers should use
648  *   mdiobus_register() rather than __mdiobus_register() unless they
649  *   need to pass a specific owner module. MDIO devices which are not
650  *   PHYs will not be brought up by this function. They are expected
651  *   to be explicitly listed in DT and instantiated by of_mdiobus_register().
652  *
653  * Returns 0 on success or < 0 on error.
654  */
__mdiobus_register(struct mii_bus * bus,struct module * owner)655 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
656 {
657 	struct mdio_device *mdiodev;
658 	struct gpio_desc *gpiod;
659 	bool prevent_c45_scan;
660 	int i, err;
661 
662 	if (!bus || !bus->name)
663 		return -EINVAL;
664 
665 	/* An access method always needs both read and write operations */
666 	if (!!bus->read != !!bus->write || !!bus->read_c45 != !!bus->write_c45)
667 		return -EINVAL;
668 
669 	/* At least one method is mandatory */
670 	if (!bus->read && !bus->read_c45)
671 		return -EINVAL;
672 
673 	if (bus->parent && bus->parent->of_node)
674 		bus->parent->of_node->fwnode.flags |=
675 					FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
676 
677 	WARN(bus->state != MDIOBUS_ALLOCATED &&
678 	     bus->state != MDIOBUS_UNREGISTERED,
679 	     "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
680 
681 	bus->owner = owner;
682 	bus->dev.parent = bus->parent;
683 	bus->dev.class = &mdio_bus_class;
684 	bus->dev.groups = NULL;
685 	dev_set_name(&bus->dev, "%s", bus->id);
686 
687 	/* We need to set state to MDIOBUS_UNREGISTERED to correctly release
688 	 * the device in mdiobus_free()
689 	 *
690 	 * State will be updated later in this function in case of success
691 	 */
692 	bus->state = MDIOBUS_UNREGISTERED;
693 
694 	err = device_register(&bus->dev);
695 	if (err) {
696 		pr_err("mii_bus %s failed to register\n", bus->id);
697 		return -EINVAL;
698 	}
699 
700 	mutex_init(&bus->mdio_lock);
701 	mutex_init(&bus->shared_lock);
702 
703 	/* assert bus level PHY GPIO reset */
704 	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
705 	if (IS_ERR(gpiod)) {
706 		err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
707 				    "mii_bus %s couldn't get reset GPIO\n",
708 				    bus->id);
709 		device_del(&bus->dev);
710 		return err;
711 	} else	if (gpiod) {
712 		bus->reset_gpiod = gpiod;
713 		fsleep(bus->reset_delay_us);
714 		gpiod_set_value_cansleep(gpiod, 0);
715 		if (bus->reset_post_delay_us > 0)
716 			fsleep(bus->reset_post_delay_us);
717 	}
718 
719 	if (bus->reset) {
720 		err = bus->reset(bus);
721 		if (err)
722 			goto error_reset_gpiod;
723 	}
724 
725 	if (bus->read) {
726 		err = mdiobus_scan_bus_c22(bus);
727 		if (err)
728 			goto error;
729 	}
730 
731 	prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
732 
733 	if (!prevent_c45_scan && bus->read_c45) {
734 		err = mdiobus_scan_bus_c45(bus);
735 		if (err)
736 			goto error;
737 	}
738 
739 	mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
740 
741 	bus->state = MDIOBUS_REGISTERED;
742 	dev_dbg(&bus->dev, "probed\n");
743 	return 0;
744 
745 error:
746 	for (i = 0; i < PHY_MAX_ADDR; i++) {
747 		mdiodev = bus->mdio_map[i];
748 		if (!mdiodev)
749 			continue;
750 
751 		mdiodev->device_remove(mdiodev);
752 		mdiodev->device_free(mdiodev);
753 	}
754 error_reset_gpiod:
755 	/* Put PHYs in RESET to save power */
756 	if (bus->reset_gpiod)
757 		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
758 
759 	device_del(&bus->dev);
760 	return err;
761 }
762 EXPORT_SYMBOL(__mdiobus_register);
763 
mdiobus_unregister(struct mii_bus * bus)764 void mdiobus_unregister(struct mii_bus *bus)
765 {
766 	struct mdio_device *mdiodev;
767 	int i;
768 
769 	if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
770 		return;
771 	bus->state = MDIOBUS_UNREGISTERED;
772 
773 	for (i = 0; i < PHY_MAX_ADDR; i++) {
774 		mdiodev = bus->mdio_map[i];
775 		if (!mdiodev)
776 			continue;
777 
778 		if (mdiodev->reset_gpio)
779 			gpiod_put(mdiodev->reset_gpio);
780 
781 		mdiodev->device_remove(mdiodev);
782 		mdiodev->device_free(mdiodev);
783 	}
784 
785 	/* Put PHYs in RESET to save power */
786 	if (bus->reset_gpiod)
787 		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
788 
789 	device_del(&bus->dev);
790 }
791 EXPORT_SYMBOL(mdiobus_unregister);
792 
793 /**
794  * mdiobus_free - free a struct mii_bus
795  * @bus: mii_bus to free
796  *
797  * This function releases the reference to the underlying device
798  * object in the mii_bus.  If this is the last reference, the mii_bus
799  * will be freed.
800  */
mdiobus_free(struct mii_bus * bus)801 void mdiobus_free(struct mii_bus *bus)
802 {
803 	/* For compatibility with error handling in drivers. */
804 	if (bus->state == MDIOBUS_ALLOCATED) {
805 		kfree(bus);
806 		return;
807 	}
808 
809 	WARN(bus->state != MDIOBUS_UNREGISTERED,
810 	     "%s: not in UNREGISTERED state\n", bus->id);
811 	bus->state = MDIOBUS_RELEASED;
812 
813 	put_device(&bus->dev);
814 }
815 EXPORT_SYMBOL(mdiobus_free);
816 
mdiobus_stats_acct(struct mdio_bus_stats * stats,bool op,int ret)817 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret)
818 {
819 	preempt_disable();
820 	u64_stats_update_begin(&stats->syncp);
821 
822 	u64_stats_inc(&stats->transfers);
823 	if (ret < 0) {
824 		u64_stats_inc(&stats->errors);
825 		goto out;
826 	}
827 
828 	if (op)
829 		u64_stats_inc(&stats->reads);
830 	else
831 		u64_stats_inc(&stats->writes);
832 out:
833 	u64_stats_update_end(&stats->syncp);
834 	preempt_enable();
835 }
836 
837 /**
838  * __mdiobus_read - Unlocked version of the mdiobus_read function
839  * @bus: the mii_bus struct
840  * @addr: the phy address
841  * @regnum: register number to read
842  *
843  * Read a MDIO bus register. Caller must hold the mdio bus lock.
844  *
845  * NOTE: MUST NOT be called from interrupt context.
846  */
__mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)847 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
848 {
849 	int retval;
850 
851 	lockdep_assert_held_once(&bus->mdio_lock);
852 
853 	if (bus->read)
854 		retval = bus->read(bus, addr, regnum);
855 	else
856 		retval = -EOPNOTSUPP;
857 
858 	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
859 	mdiobus_stats_acct(&bus->stats[addr], true, retval);
860 
861 	return retval;
862 }
863 EXPORT_SYMBOL(__mdiobus_read);
864 
865 /**
866  * __mdiobus_write - Unlocked version of the mdiobus_write function
867  * @bus: the mii_bus struct
868  * @addr: the phy address
869  * @regnum: register number to write
870  * @val: value to write to @regnum
871  *
872  * Write a MDIO bus register. Caller must hold the mdio bus lock.
873  *
874  * NOTE: MUST NOT be called from interrupt context.
875  */
__mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)876 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
877 {
878 	int err;
879 
880 	lockdep_assert_held_once(&bus->mdio_lock);
881 
882 	if (bus->write)
883 		err = bus->write(bus, addr, regnum, val);
884 	else
885 		err = -EOPNOTSUPP;
886 
887 	trace_mdio_access(bus, 0, addr, regnum, val, err);
888 	mdiobus_stats_acct(&bus->stats[addr], false, err);
889 
890 	return err;
891 }
892 EXPORT_SYMBOL(__mdiobus_write);
893 
894 /**
895  * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function
896  * @bus: the mii_bus struct
897  * @addr: the phy address
898  * @regnum: register number to modify
899  * @mask: bit mask of bits to clear
900  * @set: bit mask of bits to set
901  *
902  * Read, modify, and if any change, write the register value back to the
903  * device. Any error returns a negative number.
904  *
905  * NOTE: MUST NOT be called from interrupt context.
906  */
__mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)907 int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
908 			     u16 mask, u16 set)
909 {
910 	int new, ret;
911 
912 	ret = __mdiobus_read(bus, addr, regnum);
913 	if (ret < 0)
914 		return ret;
915 
916 	new = (ret & ~mask) | set;
917 	if (new == ret)
918 		return 0;
919 
920 	ret = __mdiobus_write(bus, addr, regnum, new);
921 
922 	return ret < 0 ? ret : 1;
923 }
924 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
925 
926 /**
927  * __mdiobus_c45_read - Unlocked version of the mdiobus_c45_read function
928  * @bus: the mii_bus struct
929  * @addr: the phy address
930  * @devad: device address to read
931  * @regnum: register number to read
932  *
933  * Read a MDIO bus register. Caller must hold the mdio bus lock.
934  *
935  * NOTE: MUST NOT be called from interrupt context.
936  */
__mdiobus_c45_read(struct mii_bus * bus,int addr,int devad,u32 regnum)937 int __mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
938 {
939 	int retval;
940 
941 	lockdep_assert_held_once(&bus->mdio_lock);
942 
943 	if (bus->read_c45)
944 		retval = bus->read_c45(bus, addr, devad, regnum);
945 	else
946 		retval = -EOPNOTSUPP;
947 
948 	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
949 	mdiobus_stats_acct(&bus->stats[addr], true, retval);
950 
951 	return retval;
952 }
953 EXPORT_SYMBOL(__mdiobus_c45_read);
954 
955 /**
956  * __mdiobus_c45_write - Unlocked version of the mdiobus_write function
957  * @bus: the mii_bus struct
958  * @addr: the phy address
959  * @devad: device address to read
960  * @regnum: register number to write
961  * @val: value to write to @regnum
962  *
963  * Write a MDIO bus register. Caller must hold the mdio bus lock.
964  *
965  * NOTE: MUST NOT be called from interrupt context.
966  */
__mdiobus_c45_write(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 val)967 int __mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
968 			u16 val)
969 {
970 	int err;
971 
972 	lockdep_assert_held_once(&bus->mdio_lock);
973 
974 	if (bus->write_c45)
975 		err = bus->write_c45(bus, addr, devad, regnum, val);
976 	else
977 		err = -EOPNOTSUPP;
978 
979 	trace_mdio_access(bus, 0, addr, regnum, val, err);
980 	mdiobus_stats_acct(&bus->stats[addr], false, err);
981 
982 	return err;
983 }
984 EXPORT_SYMBOL(__mdiobus_c45_write);
985 
986 /**
987  * __mdiobus_c45_modify_changed - Unlocked version of the mdiobus_modify function
988  * @bus: the mii_bus struct
989  * @addr: the phy address
990  * @devad: device address to read
991  * @regnum: register number to modify
992  * @mask: bit mask of bits to clear
993  * @set: bit mask of bits to set
994  *
995  * Read, modify, and if any change, write the register value back to the
996  * device. Any error returns a negative number.
997  *
998  * NOTE: MUST NOT be called from interrupt context.
999  */
__mdiobus_c45_modify_changed(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 mask,u16 set)1000 static int __mdiobus_c45_modify_changed(struct mii_bus *bus, int addr,
1001 					int devad, u32 regnum, u16 mask,
1002 					u16 set)
1003 {
1004 	int new, ret;
1005 
1006 	ret = __mdiobus_c45_read(bus, addr, devad, regnum);
1007 	if (ret < 0)
1008 		return ret;
1009 
1010 	new = (ret & ~mask) | set;
1011 	if (new == ret)
1012 		return 0;
1013 
1014 	ret = __mdiobus_c45_write(bus, addr, devad, regnum, new);
1015 
1016 	return ret < 0 ? ret : 1;
1017 }
1018 
1019 /**
1020  * mdiobus_read_nested - Nested version of the mdiobus_read function
1021  * @bus: the mii_bus struct
1022  * @addr: the phy address
1023  * @regnum: register number to read
1024  *
1025  * In case of nested MDIO bus access avoid lockdep false positives by
1026  * using mutex_lock_nested().
1027  *
1028  * NOTE: MUST NOT be called from interrupt context,
1029  * because the bus read/write functions may wait for an interrupt
1030  * to conclude the operation.
1031  */
mdiobus_read_nested(struct mii_bus * bus,int addr,u32 regnum)1032 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
1033 {
1034 	int retval;
1035 
1036 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
1037 	retval = __mdiobus_read(bus, addr, regnum);
1038 	mutex_unlock(&bus->mdio_lock);
1039 
1040 	return retval;
1041 }
1042 EXPORT_SYMBOL(mdiobus_read_nested);
1043 
1044 /**
1045  * mdiobus_read - Convenience function for reading a given MII mgmt register
1046  * @bus: the mii_bus struct
1047  * @addr: the phy address
1048  * @regnum: register number to read
1049  *
1050  * NOTE: MUST NOT be called from interrupt context,
1051  * because the bus read/write functions may wait for an interrupt
1052  * to conclude the operation.
1053  */
mdiobus_read(struct mii_bus * bus,int addr,u32 regnum)1054 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
1055 {
1056 	int retval;
1057 
1058 	mutex_lock(&bus->mdio_lock);
1059 	retval = __mdiobus_read(bus, addr, regnum);
1060 	mutex_unlock(&bus->mdio_lock);
1061 
1062 	return retval;
1063 }
1064 EXPORT_SYMBOL(mdiobus_read);
1065 
1066 /**
1067  * mdiobus_c45_read - Convenience function for reading a given MII mgmt register
1068  * @bus: the mii_bus struct
1069  * @addr: the phy address
1070  * @devad: device address to read
1071  * @regnum: register number to read
1072  *
1073  * NOTE: MUST NOT be called from interrupt context,
1074  * because the bus read/write functions may wait for an interrupt
1075  * to conclude the operation.
1076  */
mdiobus_c45_read(struct mii_bus * bus,int addr,int devad,u32 regnum)1077 int mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
1078 {
1079 	int retval;
1080 
1081 	mutex_lock(&bus->mdio_lock);
1082 	retval = __mdiobus_c45_read(bus, addr, devad, regnum);
1083 	mutex_unlock(&bus->mdio_lock);
1084 
1085 	return retval;
1086 }
1087 EXPORT_SYMBOL(mdiobus_c45_read);
1088 
1089 /**
1090  * mdiobus_c45_read_nested - Nested version of the mdiobus_c45_read function
1091  * @bus: the mii_bus struct
1092  * @addr: the phy address
1093  * @devad: device address to read
1094  * @regnum: register number to read
1095  *
1096  * In case of nested MDIO bus access avoid lockdep false positives by
1097  * using mutex_lock_nested().
1098  *
1099  * NOTE: MUST NOT be called from interrupt context,
1100  * because the bus read/write functions may wait for an interrupt
1101  * to conclude the operation.
1102  */
mdiobus_c45_read_nested(struct mii_bus * bus,int addr,int devad,u32 regnum)1103 int mdiobus_c45_read_nested(struct mii_bus *bus, int addr, int devad,
1104 			    u32 regnum)
1105 {
1106 	int retval;
1107 
1108 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
1109 	retval = __mdiobus_c45_read(bus, addr, devad, regnum);
1110 	mutex_unlock(&bus->mdio_lock);
1111 
1112 	return retval;
1113 }
1114 EXPORT_SYMBOL(mdiobus_c45_read_nested);
1115 
1116 /**
1117  * mdiobus_write_nested - Nested version of the mdiobus_write function
1118  * @bus: the mii_bus struct
1119  * @addr: the phy address
1120  * @regnum: register number to write
1121  * @val: value to write to @regnum
1122  *
1123  * In case of nested MDIO bus access avoid lockdep false positives by
1124  * using mutex_lock_nested().
1125  *
1126  * NOTE: MUST NOT be called from interrupt context,
1127  * because the bus read/write functions may wait for an interrupt
1128  * to conclude the operation.
1129  */
mdiobus_write_nested(struct mii_bus * bus,int addr,u32 regnum,u16 val)1130 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
1131 {
1132 	int err;
1133 
1134 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
1135 	err = __mdiobus_write(bus, addr, regnum, val);
1136 	mutex_unlock(&bus->mdio_lock);
1137 
1138 	return err;
1139 }
1140 EXPORT_SYMBOL(mdiobus_write_nested);
1141 
1142 /**
1143  * mdiobus_write - Convenience function for writing a given MII mgmt register
1144  * @bus: the mii_bus struct
1145  * @addr: the phy address
1146  * @regnum: register number to write
1147  * @val: value to write to @regnum
1148  *
1149  * NOTE: MUST NOT be called from interrupt context,
1150  * because the bus read/write functions may wait for an interrupt
1151  * to conclude the operation.
1152  */
mdiobus_write(struct mii_bus * bus,int addr,u32 regnum,u16 val)1153 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
1154 {
1155 	int err;
1156 
1157 	mutex_lock(&bus->mdio_lock);
1158 	err = __mdiobus_write(bus, addr, regnum, val);
1159 	mutex_unlock(&bus->mdio_lock);
1160 
1161 	return err;
1162 }
1163 EXPORT_SYMBOL(mdiobus_write);
1164 
1165 /**
1166  * mdiobus_c45_write - Convenience function for writing a given MII mgmt register
1167  * @bus: the mii_bus struct
1168  * @addr: the phy address
1169  * @devad: device address to read
1170  * @regnum: register number to write
1171  * @val: value to write to @regnum
1172  *
1173  * NOTE: MUST NOT be called from interrupt context,
1174  * because the bus read/write functions may wait for an interrupt
1175  * to conclude the operation.
1176  */
mdiobus_c45_write(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 val)1177 int mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
1178 		      u16 val)
1179 {
1180 	int err;
1181 
1182 	mutex_lock(&bus->mdio_lock);
1183 	err = __mdiobus_c45_write(bus, addr, devad, regnum, val);
1184 	mutex_unlock(&bus->mdio_lock);
1185 
1186 	return err;
1187 }
1188 EXPORT_SYMBOL(mdiobus_c45_write);
1189 
1190 /**
1191  * mdiobus_c45_write_nested - Nested version of the mdiobus_c45_write function
1192  * @bus: the mii_bus struct
1193  * @addr: the phy address
1194  * @devad: device address to read
1195  * @regnum: register number to write
1196  * @val: value to write to @regnum
1197  *
1198  * In case of nested MDIO bus access avoid lockdep false positives by
1199  * using mutex_lock_nested().
1200  *
1201  * NOTE: MUST NOT be called from interrupt context,
1202  * because the bus read/write functions may wait for an interrupt
1203  * to conclude the operation.
1204  */
mdiobus_c45_write_nested(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 val)1205 int mdiobus_c45_write_nested(struct mii_bus *bus, int addr, int devad,
1206 			     u32 regnum, u16 val)
1207 {
1208 	int err;
1209 
1210 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
1211 	err = __mdiobus_c45_write(bus, addr, devad, regnum, val);
1212 	mutex_unlock(&bus->mdio_lock);
1213 
1214 	return err;
1215 }
1216 EXPORT_SYMBOL(mdiobus_c45_write_nested);
1217 
1218 /*
1219  * __mdiobus_modify - Convenience function for modifying a given mdio device
1220  *	register
1221  * @bus: the mii_bus struct
1222  * @addr: the phy address
1223  * @regnum: register number to write
1224  * @mask: bit mask of bits to clear
1225  * @set: bit mask of bits to set
1226  */
__mdiobus_modify(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)1227 int __mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask,
1228 		     u16 set)
1229 {
1230 	int err;
1231 
1232 	err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
1233 
1234 	return err < 0 ? err : 0;
1235 }
1236 EXPORT_SYMBOL_GPL(__mdiobus_modify);
1237 
1238 /**
1239  * mdiobus_modify - Convenience function for modifying a given mdio device
1240  *	register
1241  * @bus: the mii_bus struct
1242  * @addr: the phy address
1243  * @regnum: register number to write
1244  * @mask: bit mask of bits to clear
1245  * @set: bit mask of bits to set
1246  */
mdiobus_modify(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)1247 int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set)
1248 {
1249 	int err;
1250 
1251 	mutex_lock(&bus->mdio_lock);
1252 	err = __mdiobus_modify(bus, addr, regnum, mask, set);
1253 	mutex_unlock(&bus->mdio_lock);
1254 
1255 	return err;
1256 }
1257 EXPORT_SYMBOL_GPL(mdiobus_modify);
1258 
1259 /**
1260  * mdiobus_c45_modify - Convenience function for modifying a given mdio device
1261  *	register
1262  * @bus: the mii_bus struct
1263  * @addr: the phy address
1264  * @devad: device address to read
1265  * @regnum: register number to write
1266  * @mask: bit mask of bits to clear
1267  * @set: bit mask of bits to set
1268  */
mdiobus_c45_modify(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 mask,u16 set)1269 int mdiobus_c45_modify(struct mii_bus *bus, int addr, int devad, u32 regnum,
1270 		       u16 mask, u16 set)
1271 {
1272 	int err;
1273 
1274 	mutex_lock(&bus->mdio_lock);
1275 	err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum,
1276 					   mask, set);
1277 	mutex_unlock(&bus->mdio_lock);
1278 
1279 	return err < 0 ? err : 0;
1280 }
1281 EXPORT_SYMBOL_GPL(mdiobus_c45_modify);
1282 
1283 /**
1284  * mdiobus_modify_changed - Convenience function for modifying a given mdio
1285  *	device register and returning if it changed
1286  * @bus: the mii_bus struct
1287  * @addr: the phy address
1288  * @regnum: register number to write
1289  * @mask: bit mask of bits to clear
1290  * @set: bit mask of bits to set
1291  */
mdiobus_modify_changed(struct mii_bus * bus,int addr,u32 regnum,u16 mask,u16 set)1292 int mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
1293 			   u16 mask, u16 set)
1294 {
1295 	int err;
1296 
1297 	mutex_lock(&bus->mdio_lock);
1298 	err = __mdiobus_modify_changed(bus, addr, regnum, mask, set);
1299 	mutex_unlock(&bus->mdio_lock);
1300 
1301 	return err;
1302 }
1303 EXPORT_SYMBOL_GPL(mdiobus_modify_changed);
1304 
1305 /**
1306  * mdiobus_c45_modify_changed - Convenience function for modifying a given mdio
1307  *	device register and returning if it changed
1308  * @bus: the mii_bus struct
1309  * @addr: the phy address
1310  * @devad: device address to read
1311  * @regnum: register number to write
1312  * @mask: bit mask of bits to clear
1313  * @set: bit mask of bits to set
1314  */
mdiobus_c45_modify_changed(struct mii_bus * bus,int addr,int devad,u32 regnum,u16 mask,u16 set)1315 int mdiobus_c45_modify_changed(struct mii_bus *bus, int addr, int devad,
1316 			       u32 regnum, u16 mask, u16 set)
1317 {
1318 	int err;
1319 
1320 	mutex_lock(&bus->mdio_lock);
1321 	err = __mdiobus_c45_modify_changed(bus, addr, devad, regnum, mask, set);
1322 	mutex_unlock(&bus->mdio_lock);
1323 
1324 	return err;
1325 }
1326 EXPORT_SYMBOL_GPL(mdiobus_c45_modify_changed);
1327 
1328 /**
1329  * mdio_bus_match - determine if given MDIO driver supports the given
1330  *		    MDIO device
1331  * @dev: target MDIO device
1332  * @drv: given MDIO driver
1333  *
1334  * Description: Given a MDIO device, and a MDIO driver, return 1 if
1335  *   the driver supports the device.  Otherwise, return 0. This may
1336  *   require calling the devices own match function, since different classes
1337  *   of MDIO devices have different match criteria.
1338  */
mdio_bus_match(struct device * dev,struct device_driver * drv)1339 static int mdio_bus_match(struct device *dev, struct device_driver *drv)
1340 {
1341 	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
1342 	struct mdio_device *mdio = to_mdio_device(dev);
1343 
1344 	/* Both the driver and device must type-match */
1345 	if (!(mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) !=
1346 	    !(mdio->flags & MDIO_DEVICE_FLAG_PHY))
1347 		return 0;
1348 
1349 	if (of_driver_match_device(dev, drv))
1350 		return 1;
1351 
1352 	if (mdio->bus_match)
1353 		return mdio->bus_match(dev, drv);
1354 
1355 	return 0;
1356 }
1357 
mdio_uevent(const struct device * dev,struct kobj_uevent_env * env)1358 static int mdio_uevent(const struct device *dev, struct kobj_uevent_env *env)
1359 {
1360 	int rc;
1361 
1362 	/* Some devices have extra OF data and an OF-style MODALIAS */
1363 	rc = of_device_uevent_modalias(dev, env);
1364 	if (rc != -ENODEV)
1365 		return rc;
1366 
1367 	return 0;
1368 }
1369 
1370 static struct attribute *mdio_bus_device_statistics_attrs[] = {
1371 	&dev_attr_mdio_bus_device_transfers.attr.attr,
1372 	&dev_attr_mdio_bus_device_errors.attr.attr,
1373 	&dev_attr_mdio_bus_device_writes.attr.attr,
1374 	&dev_attr_mdio_bus_device_reads.attr.attr,
1375 	NULL,
1376 };
1377 
1378 static const struct attribute_group mdio_bus_device_statistics_group = {
1379 	.name	= "statistics",
1380 	.attrs	= mdio_bus_device_statistics_attrs,
1381 };
1382 
1383 static const struct attribute_group *mdio_bus_dev_groups[] = {
1384 	&mdio_bus_device_statistics_group,
1385 	NULL,
1386 };
1387 
1388 struct bus_type mdio_bus_type = {
1389 	.name		= "mdio_bus",
1390 	.dev_groups	= mdio_bus_dev_groups,
1391 	.match		= mdio_bus_match,
1392 	.uevent		= mdio_uevent,
1393 };
1394 EXPORT_SYMBOL(mdio_bus_type);
1395 
mdio_bus_init(void)1396 int __init mdio_bus_init(void)
1397 {
1398 	int ret;
1399 
1400 	ret = class_register(&mdio_bus_class);
1401 	if (!ret) {
1402 		ret = bus_register(&mdio_bus_type);
1403 		if (ret)
1404 			class_unregister(&mdio_bus_class);
1405 	}
1406 
1407 	return ret;
1408 }
1409 
1410 #if IS_ENABLED(CONFIG_PHYLIB)
mdio_bus_exit(void)1411 void mdio_bus_exit(void)
1412 {
1413 	class_unregister(&mdio_bus_class);
1414 	bus_unregister(&mdio_bus_type);
1415 }
1416 EXPORT_SYMBOL_GPL(mdio_bus_exit);
1417 #else
1418 module_init(mdio_bus_init);
1419 /* no module_exit, intentional */
1420 MODULE_LICENSE("GPL");
1421 MODULE_DESCRIPTION("MDIO bus/device layer");
1422 #endif
1423