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/mii.h> 23 #include <linux/mm.h> 24 #include <linux/module.h> 25 #include <linux/netdevice.h> 26 #include <linux/of_device.h> 27 #include <linux/of_gpio.h> 28 #include <linux/of_mdio.h> 29 #include <linux/phy.h> 30 #include <linux/reset.h> 31 #include <linux/skbuff.h> 32 #include <linux/slab.h> 33 #include <linux/spinlock.h> 34 #include <linux/string.h> 35 #include <linux/uaccess.h> 36 #include <linux/unistd.h> 37 38 #define CREATE_TRACE_POINTS 39 #include <trace/events/mdio.h> 40 41 #include "mdio-boardinfo.h" 42 43 static int mdiobus_register_gpiod(struct mdio_device *mdiodev) 44 { 45 /* Deassert the optional reset signal */ 46 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev, 47 "reset", GPIOD_OUT_LOW); 48 if (IS_ERR(mdiodev->reset_gpio)) 49 return PTR_ERR(mdiodev->reset_gpio); 50 51 if (mdiodev->reset_gpio) 52 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset"); 53 54 return 0; 55 } 56 57 static int mdiobus_register_reset(struct mdio_device *mdiodev) 58 { 59 struct reset_control *reset; 60 61 reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy"); 62 if (IS_ERR(reset)) 63 return PTR_ERR(reset); 64 65 mdiodev->reset_ctrl = reset; 66 67 return 0; 68 } 69 70 int mdiobus_register_device(struct mdio_device *mdiodev) 71 { 72 int err; 73 74 if (mdiodev->bus->mdio_map[mdiodev->addr]) 75 return -EBUSY; 76 77 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) { 78 err = mdiobus_register_gpiod(mdiodev); 79 if (err) 80 return err; 81 82 err = mdiobus_register_reset(mdiodev); 83 if (err) 84 return err; 85 86 /* Assert the reset signal */ 87 mdio_device_reset(mdiodev, 1); 88 } 89 90 mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev; 91 92 return 0; 93 } 94 EXPORT_SYMBOL(mdiobus_register_device); 95 96 int mdiobus_unregister_device(struct mdio_device *mdiodev) 97 { 98 if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev) 99 return -EINVAL; 100 101 reset_control_put(mdiodev->reset_ctrl); 102 103 mdiodev->bus->mdio_map[mdiodev->addr] = NULL; 104 105 return 0; 106 } 107 EXPORT_SYMBOL(mdiobus_unregister_device); 108 109 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr) 110 { 111 struct mdio_device *mdiodev = bus->mdio_map[addr]; 112 113 if (!mdiodev) 114 return NULL; 115 116 if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY)) 117 return NULL; 118 119 return container_of(mdiodev, struct phy_device, mdio); 120 } 121 EXPORT_SYMBOL(mdiobus_get_phy); 122 123 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr) 124 { 125 return bus->mdio_map[addr]; 126 } 127 EXPORT_SYMBOL(mdiobus_is_registered_device); 128 129 /** 130 * mdiobus_alloc_size - allocate a mii_bus structure 131 * @size: extra amount of memory to allocate for private storage. 132 * If non-zero, then bus->priv is points to that memory. 133 * 134 * Description: called by a bus driver to allocate an mii_bus 135 * structure to fill in. 136 */ 137 struct mii_bus *mdiobus_alloc_size(size_t size) 138 { 139 struct mii_bus *bus; 140 size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN); 141 size_t alloc_size; 142 int i; 143 144 /* If we alloc extra space, it should be aligned */ 145 if (size) 146 alloc_size = aligned_size + size; 147 else 148 alloc_size = sizeof(*bus); 149 150 bus = kzalloc(alloc_size, GFP_KERNEL); 151 if (!bus) 152 return NULL; 153 154 bus->state = MDIOBUS_ALLOCATED; 155 if (size) 156 bus->priv = (void *)bus + aligned_size; 157 158 /* Initialise the interrupts to polling and 64-bit seqcounts */ 159 for (i = 0; i < PHY_MAX_ADDR; i++) { 160 bus->irq[i] = PHY_POLL; 161 u64_stats_init(&bus->stats[i].syncp); 162 } 163 164 return bus; 165 } 166 EXPORT_SYMBOL(mdiobus_alloc_size); 167 168 /** 169 * mdiobus_release - mii_bus device release callback 170 * @d: the target struct device that contains the mii_bus 171 * 172 * Description: called when the last reference to an mii_bus is 173 * dropped, to free the underlying memory. 174 */ 175 static void mdiobus_release(struct device *d) 176 { 177 struct mii_bus *bus = to_mii_bus(d); 178 179 BUG_ON(bus->state != MDIOBUS_RELEASED && 180 /* for compatibility with error handling in drivers */ 181 bus->state != MDIOBUS_ALLOCATED); 182 kfree(bus); 183 } 184 185 struct mdio_bus_stat_attr { 186 int addr; 187 unsigned int field_offset; 188 }; 189 190 static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset) 191 { 192 const char *p = (const char *)s + offset; 193 unsigned int start; 194 u64 val = 0; 195 196 do { 197 start = u64_stats_fetch_begin(&s->syncp); 198 val = u64_stats_read((const u64_stats_t *)p); 199 } while (u64_stats_fetch_retry(&s->syncp, start)); 200 201 return val; 202 } 203 204 static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset) 205 { 206 unsigned int i; 207 u64 val = 0; 208 209 for (i = 0; i < PHY_MAX_ADDR; i++) 210 val += mdio_bus_get_stat(&bus->stats[i], offset); 211 212 return val; 213 } 214 215 static ssize_t mdio_bus_stat_field_show(struct device *dev, 216 struct device_attribute *attr, 217 char *buf) 218 { 219 struct mii_bus *bus = to_mii_bus(dev); 220 struct mdio_bus_stat_attr *sattr; 221 struct dev_ext_attribute *eattr; 222 u64 val; 223 224 eattr = container_of(attr, struct dev_ext_attribute, attr); 225 sattr = eattr->var; 226 227 if (sattr->addr < 0) 228 val = mdio_bus_get_global_stat(bus, sattr->field_offset); 229 else 230 val = mdio_bus_get_stat(&bus->stats[sattr->addr], 231 sattr->field_offset); 232 233 return sprintf(buf, "%llu\n", val); 234 } 235 236 static ssize_t mdio_bus_device_stat_field_show(struct device *dev, 237 struct device_attribute *attr, 238 char *buf) 239 { 240 struct mdio_device *mdiodev = to_mdio_device(dev); 241 struct mii_bus *bus = mdiodev->bus; 242 struct mdio_bus_stat_attr *sattr; 243 struct dev_ext_attribute *eattr; 244 int addr = mdiodev->addr; 245 u64 val; 246 247 eattr = container_of(attr, struct dev_ext_attribute, attr); 248 sattr = eattr->var; 249 250 val = mdio_bus_get_stat(&bus->stats[addr], sattr->field_offset); 251 252 return sprintf(buf, "%llu\n", val); 253 } 254 255 #define MDIO_BUS_STATS_ATTR_DECL(field, file) \ 256 static struct dev_ext_attribute dev_attr_mdio_bus_##field = { \ 257 .attr = { .attr = { .name = file, .mode = 0444 }, \ 258 .show = mdio_bus_stat_field_show, \ 259 }, \ 260 .var = &((struct mdio_bus_stat_attr) { \ 261 -1, offsetof(struct mdio_bus_stats, field) \ 262 }), \ 263 }; \ 264 static struct dev_ext_attribute dev_attr_mdio_bus_device_##field = { \ 265 .attr = { .attr = { .name = file, .mode = 0444 }, \ 266 .show = mdio_bus_device_stat_field_show, \ 267 }, \ 268 .var = &((struct mdio_bus_stat_attr) { \ 269 -1, offsetof(struct mdio_bus_stats, field) \ 270 }), \ 271 }; 272 273 #define MDIO_BUS_STATS_ATTR(field) \ 274 MDIO_BUS_STATS_ATTR_DECL(field, __stringify(field)) 275 276 MDIO_BUS_STATS_ATTR(transfers); 277 MDIO_BUS_STATS_ATTR(errors); 278 MDIO_BUS_STATS_ATTR(writes); 279 MDIO_BUS_STATS_ATTR(reads); 280 281 #define MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, file) \ 282 static struct dev_ext_attribute dev_attr_mdio_bus_addr_##field##_##addr = { \ 283 .attr = { .attr = { .name = file, .mode = 0444 }, \ 284 .show = mdio_bus_stat_field_show, \ 285 }, \ 286 .var = &((struct mdio_bus_stat_attr) { \ 287 addr, offsetof(struct mdio_bus_stats, field) \ 288 }), \ 289 } 290 291 #define MDIO_BUS_STATS_ADDR_ATTR(field, addr) \ 292 MDIO_BUS_STATS_ADDR_ATTR_DECL(field, addr, \ 293 __stringify(field) "_" __stringify(addr)) 294 295 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(addr) \ 296 MDIO_BUS_STATS_ADDR_ATTR(transfers, addr); \ 297 MDIO_BUS_STATS_ADDR_ATTR(errors, addr); \ 298 MDIO_BUS_STATS_ADDR_ATTR(writes, addr); \ 299 MDIO_BUS_STATS_ADDR_ATTR(reads, addr) \ 300 301 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(0); 302 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(1); 303 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(2); 304 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(3); 305 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(4); 306 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(5); 307 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(6); 308 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(7); 309 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(8); 310 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(9); 311 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(10); 312 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(11); 313 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(12); 314 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(13); 315 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(14); 316 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(15); 317 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(16); 318 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(17); 319 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(18); 320 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(19); 321 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(20); 322 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(21); 323 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(22); 324 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(23); 325 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(24); 326 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(25); 327 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(26); 328 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(27); 329 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(28); 330 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(29); 331 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(30); 332 MDIO_BUS_STATS_ADDR_ATTR_GROUP_DECL(31); 333 334 #define MDIO_BUS_STATS_ADDR_ATTR_GROUP(addr) \ 335 &dev_attr_mdio_bus_addr_transfers_##addr.attr.attr, \ 336 &dev_attr_mdio_bus_addr_errors_##addr.attr.attr, \ 337 &dev_attr_mdio_bus_addr_writes_##addr.attr.attr, \ 338 &dev_attr_mdio_bus_addr_reads_##addr.attr.attr \ 339 340 static struct attribute *mdio_bus_statistics_attrs[] = { 341 &dev_attr_mdio_bus_transfers.attr.attr, 342 &dev_attr_mdio_bus_errors.attr.attr, 343 &dev_attr_mdio_bus_writes.attr.attr, 344 &dev_attr_mdio_bus_reads.attr.attr, 345 MDIO_BUS_STATS_ADDR_ATTR_GROUP(0), 346 MDIO_BUS_STATS_ADDR_ATTR_GROUP(1), 347 MDIO_BUS_STATS_ADDR_ATTR_GROUP(2), 348 MDIO_BUS_STATS_ADDR_ATTR_GROUP(3), 349 MDIO_BUS_STATS_ADDR_ATTR_GROUP(4), 350 MDIO_BUS_STATS_ADDR_ATTR_GROUP(5), 351 MDIO_BUS_STATS_ADDR_ATTR_GROUP(6), 352 MDIO_BUS_STATS_ADDR_ATTR_GROUP(7), 353 MDIO_BUS_STATS_ADDR_ATTR_GROUP(8), 354 MDIO_BUS_STATS_ADDR_ATTR_GROUP(9), 355 MDIO_BUS_STATS_ADDR_ATTR_GROUP(10), 356 MDIO_BUS_STATS_ADDR_ATTR_GROUP(11), 357 MDIO_BUS_STATS_ADDR_ATTR_GROUP(12), 358 MDIO_BUS_STATS_ADDR_ATTR_GROUP(13), 359 MDIO_BUS_STATS_ADDR_ATTR_GROUP(14), 360 MDIO_BUS_STATS_ADDR_ATTR_GROUP(15), 361 MDIO_BUS_STATS_ADDR_ATTR_GROUP(16), 362 MDIO_BUS_STATS_ADDR_ATTR_GROUP(17), 363 MDIO_BUS_STATS_ADDR_ATTR_GROUP(18), 364 MDIO_BUS_STATS_ADDR_ATTR_GROUP(19), 365 MDIO_BUS_STATS_ADDR_ATTR_GROUP(20), 366 MDIO_BUS_STATS_ADDR_ATTR_GROUP(21), 367 MDIO_BUS_STATS_ADDR_ATTR_GROUP(22), 368 MDIO_BUS_STATS_ADDR_ATTR_GROUP(23), 369 MDIO_BUS_STATS_ADDR_ATTR_GROUP(24), 370 MDIO_BUS_STATS_ADDR_ATTR_GROUP(25), 371 MDIO_BUS_STATS_ADDR_ATTR_GROUP(26), 372 MDIO_BUS_STATS_ADDR_ATTR_GROUP(27), 373 MDIO_BUS_STATS_ADDR_ATTR_GROUP(28), 374 MDIO_BUS_STATS_ADDR_ATTR_GROUP(29), 375 MDIO_BUS_STATS_ADDR_ATTR_GROUP(30), 376 MDIO_BUS_STATS_ADDR_ATTR_GROUP(31), 377 NULL, 378 }; 379 380 static const struct attribute_group mdio_bus_statistics_group = { 381 .name = "statistics", 382 .attrs = mdio_bus_statistics_attrs, 383 }; 384 385 static const struct attribute_group *mdio_bus_groups[] = { 386 &mdio_bus_statistics_group, 387 NULL, 388 }; 389 390 static struct class mdio_bus_class = { 391 .name = "mdio_bus", 392 .dev_release = mdiobus_release, 393 .dev_groups = mdio_bus_groups, 394 }; 395 396 /** 397 * mdio_find_bus - Given the name of a mdiobus, find the mii_bus. 398 * @mdio_name: The name of a mdiobus. 399 * 400 * Returns a reference to the mii_bus, or NULL if none found. The 401 * embedded struct device will have its reference count incremented, 402 * and this must be put_deviced'ed once the bus is finished with. 403 */ 404 struct mii_bus *mdio_find_bus(const char *mdio_name) 405 { 406 struct device *d; 407 408 d = class_find_device_by_name(&mdio_bus_class, mdio_name); 409 return d ? to_mii_bus(d) : NULL; 410 } 411 EXPORT_SYMBOL(mdio_find_bus); 412 413 #if IS_ENABLED(CONFIG_OF_MDIO) 414 /** 415 * of_mdio_find_bus - Given an mii_bus node, find the mii_bus. 416 * @mdio_bus_np: Pointer to the mii_bus. 417 * 418 * Returns a reference to the mii_bus, or NULL if none found. The 419 * embedded struct device will have its reference count incremented, 420 * and this must be put once the bus is finished with. 421 * 422 * Because the association of a device_node and mii_bus is made via 423 * of_mdiobus_register(), the mii_bus cannot be found before it is 424 * registered with of_mdiobus_register(). 425 * 426 */ 427 struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np) 428 { 429 struct device *d; 430 431 if (!mdio_bus_np) 432 return NULL; 433 434 d = class_find_device_by_of_node(&mdio_bus_class, mdio_bus_np); 435 return d ? to_mii_bus(d) : NULL; 436 } 437 EXPORT_SYMBOL(of_mdio_find_bus); 438 439 /* Walk the list of subnodes of a mdio bus and look for a node that 440 * matches the mdio device's address with its 'reg' property. If 441 * found, set the of_node pointer for the mdio device. This allows 442 * auto-probed phy devices to be supplied with information passed in 443 * via DT. 444 */ 445 static void of_mdiobus_link_mdiodev(struct mii_bus *bus, 446 struct mdio_device *mdiodev) 447 { 448 struct device *dev = &mdiodev->dev; 449 struct device_node *child; 450 451 if (dev->of_node || !bus->dev.of_node) 452 return; 453 454 for_each_available_child_of_node(bus->dev.of_node, child) { 455 int addr; 456 457 addr = of_mdio_parse_addr(dev, child); 458 if (addr < 0) 459 continue; 460 461 if (addr == mdiodev->addr) { 462 device_set_node(dev, of_fwnode_handle(child)); 463 return; 464 } 465 } 466 } 467 #else /* !IS_ENABLED(CONFIG_OF_MDIO) */ 468 static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio, 469 struct mdio_device *mdiodev) 470 { 471 } 472 #endif 473 474 /** 475 * mdiobus_create_device - create a full MDIO device given 476 * a mdio_board_info structure 477 * @bus: MDIO bus to create the devices on 478 * @bi: mdio_board_info structure describing the devices 479 * 480 * Returns 0 on success or < 0 on error. 481 */ 482 static int mdiobus_create_device(struct mii_bus *bus, 483 struct mdio_board_info *bi) 484 { 485 struct mdio_device *mdiodev; 486 int ret = 0; 487 488 mdiodev = mdio_device_create(bus, bi->mdio_addr); 489 if (IS_ERR(mdiodev)) 490 return -ENODEV; 491 492 strncpy(mdiodev->modalias, bi->modalias, 493 sizeof(mdiodev->modalias)); 494 mdiodev->bus_match = mdio_device_bus_match; 495 mdiodev->dev.platform_data = (void *)bi->platform_data; 496 497 ret = mdio_device_register(mdiodev); 498 if (ret) 499 mdio_device_free(mdiodev); 500 501 return ret; 502 } 503 504 /** 505 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus 506 * @bus: target mii_bus 507 * @owner: module containing bus accessor functions 508 * 509 * Description: Called by a bus driver to bring up all the PHYs 510 * on a given bus, and attach them to the bus. Drivers should use 511 * mdiobus_register() rather than __mdiobus_register() unless they 512 * need to pass a specific owner module. MDIO devices which are not 513 * PHYs will not be brought up by this function. They are expected 514 * to be explicitly listed in DT and instantiated by of_mdiobus_register(). 515 * 516 * Returns 0 on success or < 0 on error. 517 */ 518 int __mdiobus_register(struct mii_bus *bus, struct module *owner) 519 { 520 struct mdio_device *mdiodev; 521 int i, err; 522 struct gpio_desc *gpiod; 523 524 if (NULL == bus || NULL == bus->name || 525 NULL == bus->read || NULL == bus->write) 526 return -EINVAL; 527 528 BUG_ON(bus->state != MDIOBUS_ALLOCATED && 529 bus->state != MDIOBUS_UNREGISTERED); 530 531 bus->owner = owner; 532 bus->dev.parent = bus->parent; 533 bus->dev.class = &mdio_bus_class; 534 bus->dev.groups = NULL; 535 dev_set_name(&bus->dev, "%s", bus->id); 536 537 err = device_register(&bus->dev); 538 if (err) { 539 pr_err("mii_bus %s failed to register\n", bus->id); 540 return -EINVAL; 541 } 542 543 mutex_init(&bus->mdio_lock); 544 mutex_init(&bus->shared_lock); 545 546 /* assert bus level PHY GPIO reset */ 547 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH); 548 if (IS_ERR(gpiod)) { 549 err = dev_err_probe(&bus->dev, PTR_ERR(gpiod), 550 "mii_bus %s couldn't get reset GPIO\n", 551 bus->id); 552 device_del(&bus->dev); 553 return err; 554 } else if (gpiod) { 555 bus->reset_gpiod = gpiod; 556 fsleep(bus->reset_delay_us); 557 gpiod_set_value_cansleep(gpiod, 0); 558 if (bus->reset_post_delay_us > 0) 559 fsleep(bus->reset_post_delay_us); 560 } 561 562 if (bus->reset) { 563 err = bus->reset(bus); 564 if (err) 565 goto error_reset_gpiod; 566 } 567 568 for (i = 0; i < PHY_MAX_ADDR; i++) { 569 if ((bus->phy_mask & (1 << i)) == 0) { 570 struct phy_device *phydev; 571 572 phydev = mdiobus_scan(bus, i); 573 if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) { 574 err = PTR_ERR(phydev); 575 goto error; 576 } 577 } 578 } 579 580 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device); 581 582 bus->state = MDIOBUS_REGISTERED; 583 pr_info("%s: probed\n", bus->name); 584 return 0; 585 586 error: 587 while (--i >= 0) { 588 mdiodev = bus->mdio_map[i]; 589 if (!mdiodev) 590 continue; 591 592 mdiodev->device_remove(mdiodev); 593 mdiodev->device_free(mdiodev); 594 } 595 error_reset_gpiod: 596 /* Put PHYs in RESET to save power */ 597 if (bus->reset_gpiod) 598 gpiod_set_value_cansleep(bus->reset_gpiod, 1); 599 600 device_del(&bus->dev); 601 return err; 602 } 603 EXPORT_SYMBOL(__mdiobus_register); 604 605 void mdiobus_unregister(struct mii_bus *bus) 606 { 607 struct mdio_device *mdiodev; 608 int i; 609 610 if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED)) 611 return; 612 bus->state = MDIOBUS_UNREGISTERED; 613 614 for (i = 0; i < PHY_MAX_ADDR; i++) { 615 mdiodev = bus->mdio_map[i]; 616 if (!mdiodev) 617 continue; 618 619 if (mdiodev->reset_gpio) 620 gpiod_put(mdiodev->reset_gpio); 621 622 mdiodev->device_remove(mdiodev); 623 mdiodev->device_free(mdiodev); 624 } 625 626 /* Put PHYs in RESET to save power */ 627 if (bus->reset_gpiod) 628 gpiod_set_value_cansleep(bus->reset_gpiod, 1); 629 630 device_del(&bus->dev); 631 } 632 EXPORT_SYMBOL(mdiobus_unregister); 633 634 /** 635 * mdiobus_free - free a struct mii_bus 636 * @bus: mii_bus to free 637 * 638 * This function releases the reference to the underlying device 639 * object in the mii_bus. If this is the last reference, the mii_bus 640 * will be freed. 641 */ 642 void mdiobus_free(struct mii_bus *bus) 643 { 644 /* For compatibility with error handling in drivers. */ 645 if (bus->state == MDIOBUS_ALLOCATED) { 646 kfree(bus); 647 return; 648 } 649 650 BUG_ON(bus->state != MDIOBUS_UNREGISTERED); 651 bus->state = MDIOBUS_RELEASED; 652 653 put_device(&bus->dev); 654 } 655 EXPORT_SYMBOL(mdiobus_free); 656 657 /** 658 * mdiobus_scan - scan a bus for MDIO devices. 659 * @bus: mii_bus to scan 660 * @addr: address on bus to scan 661 * 662 * This function scans the MDIO bus, looking for devices which can be 663 * identified using a vendor/product ID in registers 2 and 3. Not all 664 * MDIO devices have such registers, but PHY devices typically 665 * do. Hence this function assumes anything found is a PHY, or can be 666 * treated as a PHY. Other MDIO devices, such as switches, will 667 * probably not be found during the scan. 668 */ 669 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr) 670 { 671 struct phy_device *phydev = ERR_PTR(-ENODEV); 672 int err; 673 674 switch (bus->probe_capabilities) { 675 case MDIOBUS_NO_CAP: 676 case MDIOBUS_C22: 677 phydev = get_phy_device(bus, addr, false); 678 break; 679 case MDIOBUS_C45: 680 phydev = get_phy_device(bus, addr, true); 681 break; 682 case MDIOBUS_C22_C45: 683 phydev = get_phy_device(bus, addr, false); 684 if (IS_ERR(phydev)) 685 phydev = get_phy_device(bus, addr, true); 686 break; 687 } 688 689 if (IS_ERR(phydev)) 690 return phydev; 691 692 /* 693 * For DT, see if the auto-probed phy has a correspoding child 694 * in the bus node, and set the of_node pointer in this case. 695 */ 696 of_mdiobus_link_mdiodev(bus, &phydev->mdio); 697 698 err = phy_device_register(phydev); 699 if (err) { 700 phy_device_free(phydev); 701 return ERR_PTR(-ENODEV); 702 } 703 704 return phydev; 705 } 706 EXPORT_SYMBOL(mdiobus_scan); 707 708 static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret) 709 { 710 preempt_disable(); 711 u64_stats_update_begin(&stats->syncp); 712 713 u64_stats_inc(&stats->transfers); 714 if (ret < 0) { 715 u64_stats_inc(&stats->errors); 716 goto out; 717 } 718 719 if (op) 720 u64_stats_inc(&stats->reads); 721 else 722 u64_stats_inc(&stats->writes); 723 out: 724 u64_stats_update_end(&stats->syncp); 725 preempt_enable(); 726 } 727 728 /** 729 * __mdiobus_read - Unlocked version of the mdiobus_read function 730 * @bus: the mii_bus struct 731 * @addr: the phy address 732 * @regnum: register number to read 733 * 734 * Read a MDIO bus register. Caller must hold the mdio bus lock. 735 * 736 * NOTE: MUST NOT be called from interrupt context. 737 */ 738 int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) 739 { 740 int retval; 741 742 lockdep_assert_held_once(&bus->mdio_lock); 743 744 retval = bus->read(bus, addr, regnum); 745 746 trace_mdio_access(bus, 1, addr, regnum, retval, retval); 747 mdiobus_stats_acct(&bus->stats[addr], true, retval); 748 749 return retval; 750 } 751 EXPORT_SYMBOL(__mdiobus_read); 752 753 /** 754 * __mdiobus_write - Unlocked version of the mdiobus_write function 755 * @bus: the mii_bus struct 756 * @addr: the phy address 757 * @regnum: register number to write 758 * @val: value to write to @regnum 759 * 760 * Write a MDIO bus register. Caller must hold the mdio bus lock. 761 * 762 * NOTE: MUST NOT be called from interrupt context. 763 */ 764 int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) 765 { 766 int err; 767 768 lockdep_assert_held_once(&bus->mdio_lock); 769 770 err = bus->write(bus, addr, regnum, val); 771 772 trace_mdio_access(bus, 0, addr, regnum, val, err); 773 mdiobus_stats_acct(&bus->stats[addr], false, err); 774 775 return err; 776 } 777 EXPORT_SYMBOL(__mdiobus_write); 778 779 /** 780 * __mdiobus_modify_changed - Unlocked version of the mdiobus_modify function 781 * @bus: the mii_bus struct 782 * @addr: the phy address 783 * @regnum: register number to modify 784 * @mask: bit mask of bits to clear 785 * @set: bit mask of bits to set 786 * 787 * Read, modify, and if any change, write the register value back to the 788 * device. Any error returns a negative number. 789 * 790 * NOTE: MUST NOT be called from interrupt context. 791 */ 792 int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum, 793 u16 mask, u16 set) 794 { 795 int new, ret; 796 797 ret = __mdiobus_read(bus, addr, regnum); 798 if (ret < 0) 799 return ret; 800 801 new = (ret & ~mask) | set; 802 if (new == ret) 803 return 0; 804 805 ret = __mdiobus_write(bus, addr, regnum, new); 806 807 return ret < 0 ? ret : 1; 808 } 809 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed); 810 811 /** 812 * mdiobus_read_nested - Nested version of the mdiobus_read function 813 * @bus: the mii_bus struct 814 * @addr: the phy address 815 * @regnum: register number to read 816 * 817 * In case of nested MDIO bus access avoid lockdep false positives by 818 * using mutex_lock_nested(). 819 * 820 * NOTE: MUST NOT be called from interrupt context, 821 * because the bus read/write functions may wait for an interrupt 822 * to conclude the operation. 823 */ 824 int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum) 825 { 826 int retval; 827 828 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED); 829 retval = __mdiobus_read(bus, addr, regnum); 830 mutex_unlock(&bus->mdio_lock); 831 832 return retval; 833 } 834 EXPORT_SYMBOL(mdiobus_read_nested); 835 836 /** 837 * mdiobus_read - Convenience function for reading a given MII mgmt register 838 * @bus: the mii_bus struct 839 * @addr: the phy address 840 * @regnum: register number to read 841 * 842 * NOTE: MUST NOT be called from interrupt context, 843 * because the bus read/write functions may wait for an interrupt 844 * to conclude the operation. 845 */ 846 int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) 847 { 848 int retval; 849 850 mutex_lock(&bus->mdio_lock); 851 retval = __mdiobus_read(bus, addr, regnum); 852 mutex_unlock(&bus->mdio_lock); 853 854 return retval; 855 } 856 EXPORT_SYMBOL(mdiobus_read); 857 858 /** 859 * mdiobus_write_nested - Nested version of the mdiobus_write function 860 * @bus: the mii_bus struct 861 * @addr: the phy address 862 * @regnum: register number to write 863 * @val: value to write to @regnum 864 * 865 * In case of nested MDIO bus access avoid lockdep false positives by 866 * using mutex_lock_nested(). 867 * 868 * NOTE: MUST NOT be called from interrupt context, 869 * because the bus read/write functions may wait for an interrupt 870 * to conclude the operation. 871 */ 872 int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val) 873 { 874 int err; 875 876 mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED); 877 err = __mdiobus_write(bus, addr, regnum, val); 878 mutex_unlock(&bus->mdio_lock); 879 880 return err; 881 } 882 EXPORT_SYMBOL(mdiobus_write_nested); 883 884 /** 885 * mdiobus_write - Convenience function for writing a given MII mgmt register 886 * @bus: the mii_bus struct 887 * @addr: the phy address 888 * @regnum: register number to write 889 * @val: value to write to @regnum 890 * 891 * NOTE: MUST NOT be called from interrupt context, 892 * because the bus read/write functions may wait for an interrupt 893 * to conclude the operation. 894 */ 895 int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) 896 { 897 int err; 898 899 mutex_lock(&bus->mdio_lock); 900 err = __mdiobus_write(bus, addr, regnum, val); 901 mutex_unlock(&bus->mdio_lock); 902 903 return err; 904 } 905 EXPORT_SYMBOL(mdiobus_write); 906 907 /** 908 * mdiobus_modify - Convenience function for modifying a given mdio device 909 * register 910 * @bus: the mii_bus struct 911 * @addr: the phy address 912 * @regnum: register number to write 913 * @mask: bit mask of bits to clear 914 * @set: bit mask of bits to set 915 */ 916 int mdiobus_modify(struct mii_bus *bus, int addr, u32 regnum, u16 mask, u16 set) 917 { 918 int err; 919 920 mutex_lock(&bus->mdio_lock); 921 err = __mdiobus_modify_changed(bus, addr, regnum, mask, set); 922 mutex_unlock(&bus->mdio_lock); 923 924 return err < 0 ? err : 0; 925 } 926 EXPORT_SYMBOL_GPL(mdiobus_modify); 927 928 /** 929 * mdio_bus_match - determine if given MDIO driver supports the given 930 * MDIO device 931 * @dev: target MDIO device 932 * @drv: given MDIO driver 933 * 934 * Description: Given a MDIO device, and a MDIO driver, return 1 if 935 * the driver supports the device. Otherwise, return 0. This may 936 * require calling the devices own match function, since different classes 937 * of MDIO devices have different match criteria. 938 */ 939 static int mdio_bus_match(struct device *dev, struct device_driver *drv) 940 { 941 struct mdio_device *mdio = to_mdio_device(dev); 942 943 if (of_driver_match_device(dev, drv)) 944 return 1; 945 946 if (mdio->bus_match) 947 return mdio->bus_match(dev, drv); 948 949 return 0; 950 } 951 952 static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env) 953 { 954 int rc; 955 956 /* Some devices have extra OF data and an OF-style MODALIAS */ 957 rc = of_device_uevent_modalias(dev, env); 958 if (rc != -ENODEV) 959 return rc; 960 961 return 0; 962 } 963 964 static struct attribute *mdio_bus_device_statistics_attrs[] = { 965 &dev_attr_mdio_bus_device_transfers.attr.attr, 966 &dev_attr_mdio_bus_device_errors.attr.attr, 967 &dev_attr_mdio_bus_device_writes.attr.attr, 968 &dev_attr_mdio_bus_device_reads.attr.attr, 969 NULL, 970 }; 971 972 static const struct attribute_group mdio_bus_device_statistics_group = { 973 .name = "statistics", 974 .attrs = mdio_bus_device_statistics_attrs, 975 }; 976 977 static const struct attribute_group *mdio_bus_dev_groups[] = { 978 &mdio_bus_device_statistics_group, 979 NULL, 980 }; 981 982 struct bus_type mdio_bus_type = { 983 .name = "mdio_bus", 984 .dev_groups = mdio_bus_dev_groups, 985 .match = mdio_bus_match, 986 .uevent = mdio_uevent, 987 }; 988 EXPORT_SYMBOL(mdio_bus_type); 989 990 int __init mdio_bus_init(void) 991 { 992 int ret; 993 994 ret = class_register(&mdio_bus_class); 995 if (!ret) { 996 ret = bus_register(&mdio_bus_type); 997 if (ret) 998 class_unregister(&mdio_bus_class); 999 } 1000 1001 return ret; 1002 } 1003 EXPORT_SYMBOL_GPL(mdio_bus_init); 1004 1005 #if IS_ENABLED(CONFIG_PHYLIB) 1006 void mdio_bus_exit(void) 1007 { 1008 class_unregister(&mdio_bus_class); 1009 bus_unregister(&mdio_bus_type); 1010 } 1011 EXPORT_SYMBOL_GPL(mdio_bus_exit); 1012 #else 1013 module_init(mdio_bus_init); 1014 /* no module_exit, intentional */ 1015 MODULE_LICENSE("GPL"); 1016 MODULE_DESCRIPTION("MDIO bus/device layer"); 1017 #endif 1018