1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp. 4 * <benh@kernel.crashing.org> 5 * and Arnd Bergmann, IBM Corp. 6 * Merged from powerpc/kernel/of_platform.c and 7 * sparc{,64}/kernel/of_device.c by Stephen Rothwell 8 */ 9 10 #define pr_fmt(fmt) "OF: " fmt 11 12 #include <linux/errno.h> 13 #include <linux/module.h> 14 #include <linux/amba/bus.h> 15 #include <linux/device.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/slab.h> 18 #include <linux/of_address.h> 19 #include <linux/of_device.h> 20 #include <linux/of_irq.h> 21 #include <linux/of_platform.h> 22 #include <linux/platform_device.h> 23 24 #include "of_private.h" 25 26 const struct of_device_id of_default_bus_match_table[] = { 27 { .compatible = "simple-bus", }, 28 { .compatible = "simple-mfd", }, 29 { .compatible = "isa", }, 30 #ifdef CONFIG_ARM_AMBA 31 { .compatible = "arm,amba-bus", }, 32 #endif /* CONFIG_ARM_AMBA */ 33 {} /* Empty terminated list */ 34 }; 35 36 /** 37 * of_find_device_by_node - Find the platform_device associated with a node 38 * @np: Pointer to device tree node 39 * 40 * Takes a reference to the embedded struct device which needs to be dropped 41 * after use. 42 * 43 * Return: platform_device pointer, or NULL if not found 44 */ 45 struct platform_device *of_find_device_by_node(struct device_node *np) 46 { 47 struct device *dev; 48 49 dev = bus_find_device_by_of_node(&platform_bus_type, np); 50 return dev ? to_platform_device(dev) : NULL; 51 } 52 EXPORT_SYMBOL(of_find_device_by_node); 53 54 int of_device_add(struct platform_device *ofdev) 55 { 56 BUG_ON(ofdev->dev.of_node == NULL); 57 58 /* name and id have to be set so that the platform bus doesn't get 59 * confused on matching */ 60 ofdev->name = dev_name(&ofdev->dev); 61 ofdev->id = PLATFORM_DEVID_NONE; 62 63 /* 64 * If this device has not binding numa node in devicetree, that is 65 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this 66 * device is on the same node as the parent. 67 */ 68 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); 69 70 return device_add(&ofdev->dev); 71 } 72 73 int of_device_register(struct platform_device *pdev) 74 { 75 device_initialize(&pdev->dev); 76 return of_device_add(pdev); 77 } 78 EXPORT_SYMBOL(of_device_register); 79 80 void of_device_unregister(struct platform_device *ofdev) 81 { 82 device_unregister(&ofdev->dev); 83 } 84 EXPORT_SYMBOL(of_device_unregister); 85 86 #ifdef CONFIG_OF_ADDRESS 87 static const struct of_device_id of_skipped_node_table[] = { 88 { .compatible = "operating-points-v2", }, 89 {} /* Empty terminated list */ 90 }; 91 92 /* 93 * The following routines scan a subtree and registers a device for 94 * each applicable node. 95 * 96 * Note: sparc doesn't use these routines because it has a different 97 * mechanism for creating devices from device tree nodes. 98 */ 99 100 /** 101 * of_device_make_bus_id - Use the device node data to assign a unique name 102 * @dev: pointer to device structure that is linked to a device tree node 103 * 104 * This routine will first try using the translated bus address to 105 * derive a unique name. If it cannot, then it will prepend names from 106 * parent nodes until a unique name can be derived. 107 */ 108 static void of_device_make_bus_id(struct device *dev) 109 { 110 struct device_node *node = dev->of_node; 111 const __be32 *reg; 112 u64 addr; 113 u32 mask; 114 115 /* Construct the name, using parent nodes if necessary to ensure uniqueness */ 116 while (node->parent) { 117 /* 118 * If the address can be translated, then that is as much 119 * uniqueness as we need. Make it the first component and return 120 */ 121 reg = of_get_property(node, "reg", NULL); 122 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) { 123 if (!of_property_read_u32(node, "mask", &mask)) 124 dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn", 125 addr, ffs(mask) - 1, node, dev_name(dev)); 126 127 else 128 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn", 129 addr, node, dev_name(dev)); 130 return; 131 } 132 133 /* format arguments only used if dev_name() resolves to NULL */ 134 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s", 135 kbasename(node->full_name), dev_name(dev)); 136 node = node->parent; 137 } 138 } 139 140 /** 141 * of_device_alloc - Allocate and initialize an of_device 142 * @np: device node to assign to device 143 * @bus_id: Name to assign to the device. May be null to use default name. 144 * @parent: Parent device. 145 */ 146 struct platform_device *of_device_alloc(struct device_node *np, 147 const char *bus_id, 148 struct device *parent) 149 { 150 struct platform_device *dev; 151 int rc, i, num_reg = 0; 152 struct resource *res; 153 154 dev = platform_device_alloc("", PLATFORM_DEVID_NONE); 155 if (!dev) 156 return NULL; 157 158 /* count the io resources */ 159 num_reg = of_address_count(np); 160 161 /* Populate the resource table */ 162 if (num_reg) { 163 res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL); 164 if (!res) { 165 platform_device_put(dev); 166 return NULL; 167 } 168 169 dev->num_resources = num_reg; 170 dev->resource = res; 171 for (i = 0; i < num_reg; i++, res++) { 172 rc = of_address_to_resource(np, i, res); 173 WARN_ON(rc); 174 } 175 } 176 177 /* setup generic device info */ 178 device_set_node(&dev->dev, of_fwnode_handle(of_node_get(np))); 179 dev->dev.parent = parent ? : &platform_bus; 180 181 if (bus_id) 182 dev_set_name(&dev->dev, "%s", bus_id); 183 else 184 of_device_make_bus_id(&dev->dev); 185 186 return dev; 187 } 188 EXPORT_SYMBOL(of_device_alloc); 189 190 /** 191 * of_platform_device_create_pdata - Alloc, initialize and register an of_device 192 * @np: pointer to node to create device for 193 * @bus_id: name to assign device 194 * @platform_data: pointer to populate platform_data pointer with 195 * @parent: Linux device model parent device. 196 * 197 * Return: Pointer to created platform device, or NULL if a device was not 198 * registered. Unavailable devices will not get registered. 199 */ 200 static struct platform_device *of_platform_device_create_pdata( 201 struct device_node *np, 202 const char *bus_id, 203 void *platform_data, 204 struct device *parent) 205 { 206 struct platform_device *dev; 207 208 if (!of_device_is_available(np) || 209 of_node_test_and_set_flag(np, OF_POPULATED)) 210 return NULL; 211 212 dev = of_device_alloc(np, bus_id, parent); 213 if (!dev) 214 goto err_clear_flag; 215 216 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); 217 if (!dev->dev.dma_mask) 218 dev->dev.dma_mask = &dev->dev.coherent_dma_mask; 219 dev->dev.bus = &platform_bus_type; 220 dev->dev.platform_data = platform_data; 221 of_msi_configure(&dev->dev, dev->dev.of_node); 222 223 if (of_device_add(dev) != 0) { 224 platform_device_put(dev); 225 goto err_clear_flag; 226 } 227 228 return dev; 229 230 err_clear_flag: 231 of_node_clear_flag(np, OF_POPULATED); 232 return NULL; 233 } 234 235 /** 236 * of_platform_device_create - Alloc, initialize and register an of_device 237 * @np: pointer to node to create device for 238 * @bus_id: name to assign device 239 * @parent: Linux device model parent device. 240 * 241 * Return: Pointer to created platform device, or NULL if a device was not 242 * registered. Unavailable devices will not get registered. 243 */ 244 struct platform_device *of_platform_device_create(struct device_node *np, 245 const char *bus_id, 246 struct device *parent) 247 { 248 return of_platform_device_create_pdata(np, bus_id, NULL, parent); 249 } 250 EXPORT_SYMBOL(of_platform_device_create); 251 252 #ifdef CONFIG_ARM_AMBA 253 static struct amba_device *of_amba_device_create(struct device_node *node, 254 const char *bus_id, 255 void *platform_data, 256 struct device *parent) 257 { 258 struct amba_device *dev; 259 int ret; 260 261 pr_debug("Creating amba device %pOF\n", node); 262 263 if (!of_device_is_available(node) || 264 of_node_test_and_set_flag(node, OF_POPULATED)) 265 return NULL; 266 267 dev = amba_device_alloc(NULL, 0, 0); 268 if (!dev) 269 goto err_clear_flag; 270 271 /* AMBA devices only support a single DMA mask */ 272 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); 273 dev->dev.dma_mask = &dev->dev.coherent_dma_mask; 274 275 /* setup generic device info */ 276 device_set_node(&dev->dev, of_fwnode_handle(node)); 277 dev->dev.parent = parent ? : &platform_bus; 278 dev->dev.platform_data = platform_data; 279 if (bus_id) 280 dev_set_name(&dev->dev, "%s", bus_id); 281 else 282 of_device_make_bus_id(&dev->dev); 283 284 /* Allow the HW Peripheral ID to be overridden */ 285 of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid); 286 287 ret = of_address_to_resource(node, 0, &dev->res); 288 if (ret) { 289 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n", 290 ret, node); 291 goto err_free; 292 } 293 294 ret = amba_device_add(dev, &iomem_resource); 295 if (ret) { 296 pr_err("amba_device_add() failed (%d) for %pOF\n", 297 ret, node); 298 goto err_free; 299 } 300 301 return dev; 302 303 err_free: 304 amba_device_put(dev); 305 err_clear_flag: 306 of_node_clear_flag(node, OF_POPULATED); 307 return NULL; 308 } 309 #else /* CONFIG_ARM_AMBA */ 310 static struct amba_device *of_amba_device_create(struct device_node *node, 311 const char *bus_id, 312 void *platform_data, 313 struct device *parent) 314 { 315 return NULL; 316 } 317 #endif /* CONFIG_ARM_AMBA */ 318 319 /* 320 * of_dev_lookup() - Given a device node, lookup the preferred Linux name 321 */ 322 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup, 323 struct device_node *np) 324 { 325 const struct of_dev_auxdata *auxdata; 326 struct resource res; 327 int compatible = 0; 328 329 if (!lookup) 330 return NULL; 331 332 auxdata = lookup; 333 for (; auxdata->compatible; auxdata++) { 334 if (!of_device_is_compatible(np, auxdata->compatible)) 335 continue; 336 compatible++; 337 if (!of_address_to_resource(np, 0, &res)) 338 if (res.start != auxdata->phys_addr) 339 continue; 340 pr_debug("%pOF: devname=%s\n", np, auxdata->name); 341 return auxdata; 342 } 343 344 if (!compatible) 345 return NULL; 346 347 /* Try compatible match if no phys_addr and name are specified */ 348 auxdata = lookup; 349 for (; auxdata->compatible; auxdata++) { 350 if (!of_device_is_compatible(np, auxdata->compatible)) 351 continue; 352 if (!auxdata->phys_addr && !auxdata->name) { 353 pr_debug("%pOF: compatible match\n", np); 354 return auxdata; 355 } 356 } 357 358 return NULL; 359 } 360 361 /** 362 * of_platform_bus_create() - Create a device for a node and its children. 363 * @bus: device node of the bus to instantiate 364 * @matches: match table for bus nodes 365 * @lookup: auxdata table for matching id and platform_data with device nodes 366 * @parent: parent for new device, or NULL for top level. 367 * @strict: require compatible property 368 * 369 * Creates a platform_device for the provided device_node, and optionally 370 * recursively create devices for all the child nodes. 371 */ 372 static int of_platform_bus_create(struct device_node *bus, 373 const struct of_device_id *matches, 374 const struct of_dev_auxdata *lookup, 375 struct device *parent, bool strict) 376 { 377 const struct of_dev_auxdata *auxdata; 378 struct device_node *child; 379 struct platform_device *dev; 380 const char *bus_id = NULL; 381 void *platform_data = NULL; 382 int rc = 0; 383 384 /* Make sure it has a compatible property */ 385 if (strict && (!of_get_property(bus, "compatible", NULL))) { 386 pr_debug("%s() - skipping %pOF, no compatible prop\n", 387 __func__, bus); 388 return 0; 389 } 390 391 /* Skip nodes for which we don't want to create devices */ 392 if (unlikely(of_match_node(of_skipped_node_table, bus))) { 393 pr_debug("%s() - skipping %pOF node\n", __func__, bus); 394 return 0; 395 } 396 397 if (of_node_check_flag(bus, OF_POPULATED_BUS)) { 398 pr_debug("%s() - skipping %pOF, already populated\n", 399 __func__, bus); 400 return 0; 401 } 402 403 auxdata = of_dev_lookup(lookup, bus); 404 if (auxdata) { 405 bus_id = auxdata->name; 406 platform_data = auxdata->platform_data; 407 } 408 409 if (of_device_is_compatible(bus, "arm,primecell")) { 410 /* 411 * Don't return an error here to keep compatibility with older 412 * device tree files. 413 */ 414 of_amba_device_create(bus, bus_id, platform_data, parent); 415 return 0; 416 } 417 418 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent); 419 if (!dev || !of_match_node(matches, bus)) 420 return 0; 421 422 for_each_child_of_node(bus, child) { 423 pr_debug(" create child: %pOF\n", child); 424 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict); 425 if (rc) { 426 of_node_put(child); 427 break; 428 } 429 } 430 of_node_set_flag(bus, OF_POPULATED_BUS); 431 return rc; 432 } 433 434 /** 435 * of_platform_bus_probe() - Probe the device-tree for platform buses 436 * @root: parent of the first level to probe or NULL for the root of the tree 437 * @matches: match table for bus nodes 438 * @parent: parent to hook devices from, NULL for toplevel 439 * 440 * Note that children of the provided root are not instantiated as devices 441 * unless the specified root itself matches the bus list and is not NULL. 442 */ 443 int of_platform_bus_probe(struct device_node *root, 444 const struct of_device_id *matches, 445 struct device *parent) 446 { 447 struct device_node *child; 448 int rc = 0; 449 450 root = root ? of_node_get(root) : of_find_node_by_path("/"); 451 if (!root) 452 return -EINVAL; 453 454 pr_debug("%s()\n", __func__); 455 pr_debug(" starting at: %pOF\n", root); 456 457 /* Do a self check of bus type, if there's a match, create children */ 458 if (of_match_node(matches, root)) { 459 rc = of_platform_bus_create(root, matches, NULL, parent, false); 460 } else for_each_child_of_node(root, child) { 461 if (!of_match_node(matches, child)) 462 continue; 463 rc = of_platform_bus_create(child, matches, NULL, parent, false); 464 if (rc) { 465 of_node_put(child); 466 break; 467 } 468 } 469 470 of_node_put(root); 471 return rc; 472 } 473 EXPORT_SYMBOL(of_platform_bus_probe); 474 475 /** 476 * of_platform_populate() - Populate platform_devices from device tree data 477 * @root: parent of the first level to probe or NULL for the root of the tree 478 * @matches: match table, NULL to use the default 479 * @lookup: auxdata table for matching id and platform_data with device nodes 480 * @parent: parent to hook devices from, NULL for toplevel 481 * 482 * Similar to of_platform_bus_probe(), this function walks the device tree 483 * and creates devices from nodes. It differs in that it follows the modern 484 * convention of requiring all device nodes to have a 'compatible' property, 485 * and it is suitable for creating devices which are children of the root 486 * node (of_platform_bus_probe will only create children of the root which 487 * are selected by the @matches argument). 488 * 489 * New board support should be using this function instead of 490 * of_platform_bus_probe(). 491 * 492 * Return: 0 on success, < 0 on failure. 493 */ 494 int of_platform_populate(struct device_node *root, 495 const struct of_device_id *matches, 496 const struct of_dev_auxdata *lookup, 497 struct device *parent) 498 { 499 struct device_node *child; 500 int rc = 0; 501 502 root = root ? of_node_get(root) : of_find_node_by_path("/"); 503 if (!root) 504 return -EINVAL; 505 506 pr_debug("%s()\n", __func__); 507 pr_debug(" starting at: %pOF\n", root); 508 509 device_links_supplier_sync_state_pause(); 510 for_each_child_of_node(root, child) { 511 rc = of_platform_bus_create(child, matches, lookup, parent, true); 512 if (rc) { 513 of_node_put(child); 514 break; 515 } 516 } 517 device_links_supplier_sync_state_resume(); 518 519 of_node_set_flag(root, OF_POPULATED_BUS); 520 521 of_node_put(root); 522 return rc; 523 } 524 EXPORT_SYMBOL_GPL(of_platform_populate); 525 526 int of_platform_default_populate(struct device_node *root, 527 const struct of_dev_auxdata *lookup, 528 struct device *parent) 529 { 530 return of_platform_populate(root, of_default_bus_match_table, lookup, 531 parent); 532 } 533 EXPORT_SYMBOL_GPL(of_platform_default_populate); 534 535 static const struct of_device_id reserved_mem_matches[] = { 536 { .compatible = "phram" }, 537 { .compatible = "qcom,rmtfs-mem" }, 538 { .compatible = "qcom,cmd-db" }, 539 { .compatible = "qcom,smem" }, 540 { .compatible = "ramoops" }, 541 { .compatible = "nvmem-rmem" }, 542 { .compatible = "google,open-dice" }, 543 {} 544 }; 545 546 static int __init of_platform_default_populate_init(void) 547 { 548 struct device_node *node; 549 550 device_links_supplier_sync_state_pause(); 551 552 if (!of_have_populated_dt()) 553 return -ENODEV; 554 555 if (IS_ENABLED(CONFIG_PPC)) { 556 struct device_node *boot_display = NULL; 557 struct platform_device *dev; 558 int display_number = 0; 559 int ret; 560 561 /* Check if we have a MacOS display without a node spec */ 562 if (of_property_present(of_chosen, "linux,bootx-noscreen")) { 563 /* 564 * The old code tried to work out which node was the MacOS 565 * display based on the address. I'm dropping that since the 566 * lack of a node spec only happens with old BootX versions 567 * (users can update) and with this code, they'll still get 568 * a display (just not the palette hacks). 569 */ 570 dev = platform_device_alloc("bootx-noscreen", 0); 571 if (WARN_ON(!dev)) 572 return -ENOMEM; 573 ret = platform_device_add(dev); 574 if (WARN_ON(ret)) { 575 platform_device_put(dev); 576 return ret; 577 } 578 } 579 580 /* 581 * For OF framebuffers, first create the device for the boot display, 582 * then for the other framebuffers. Only fail for the boot display; 583 * ignore errors for the rest. 584 */ 585 for_each_node_by_type(node, "display") { 586 if (!of_get_property(node, "linux,opened", NULL) || 587 !of_get_property(node, "linux,boot-display", NULL)) 588 continue; 589 dev = of_platform_device_create(node, "of-display", NULL); 590 of_node_put(node); 591 if (WARN_ON(!dev)) 592 return -ENOMEM; 593 boot_display = node; 594 display_number++; 595 break; 596 } 597 for_each_node_by_type(node, "display") { 598 char buf[14]; 599 const char *of_display_format = "of-display.%d"; 600 601 if (!of_get_property(node, "linux,opened", NULL) || node == boot_display) 602 continue; 603 ret = snprintf(buf, sizeof(buf), of_display_format, display_number++); 604 if (ret < sizeof(buf)) 605 of_platform_device_create(node, buf, NULL); 606 } 607 608 } else { 609 /* 610 * Handle certain compatibles explicitly, since we don't want to create 611 * platform_devices for every node in /reserved-memory with a 612 * "compatible", 613 */ 614 for_each_matching_node(node, reserved_mem_matches) 615 of_platform_device_create(node, NULL, NULL); 616 617 node = of_find_node_by_path("/firmware"); 618 if (node) { 619 of_platform_populate(node, NULL, NULL, NULL); 620 of_node_put(node); 621 } 622 623 node = of_get_compatible_child(of_chosen, "simple-framebuffer"); 624 of_platform_device_create(node, NULL, NULL); 625 of_node_put(node); 626 627 /* Populate everything else. */ 628 of_platform_default_populate(NULL, NULL, NULL); 629 } 630 631 return 0; 632 } 633 arch_initcall_sync(of_platform_default_populate_init); 634 635 static int __init of_platform_sync_state_init(void) 636 { 637 device_links_supplier_sync_state_resume(); 638 return 0; 639 } 640 late_initcall_sync(of_platform_sync_state_init); 641 642 int of_platform_device_destroy(struct device *dev, void *data) 643 { 644 /* Do not touch devices not populated from the device tree */ 645 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) 646 return 0; 647 648 /* Recurse for any nodes that were treated as busses */ 649 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS)) 650 device_for_each_child(dev, NULL, of_platform_device_destroy); 651 652 of_node_clear_flag(dev->of_node, OF_POPULATED); 653 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS); 654 655 if (dev->bus == &platform_bus_type) 656 platform_device_unregister(to_platform_device(dev)); 657 #ifdef CONFIG_ARM_AMBA 658 else if (dev->bus == &amba_bustype) 659 amba_device_unregister(to_amba_device(dev)); 660 #endif 661 662 return 0; 663 } 664 EXPORT_SYMBOL_GPL(of_platform_device_destroy); 665 666 /** 667 * of_platform_depopulate() - Remove devices populated from device tree 668 * @parent: device which children will be removed 669 * 670 * Complementary to of_platform_populate(), this function removes children 671 * of the given device (and, recurrently, their children) that have been 672 * created from their respective device tree nodes (and only those, 673 * leaving others - eg. manually created - unharmed). 674 */ 675 void of_platform_depopulate(struct device *parent) 676 { 677 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) { 678 device_for_each_child_reverse(parent, NULL, of_platform_device_destroy); 679 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS); 680 } 681 } 682 EXPORT_SYMBOL_GPL(of_platform_depopulate); 683 684 static void devm_of_platform_populate_release(struct device *dev, void *res) 685 { 686 of_platform_depopulate(*(struct device **)res); 687 } 688 689 /** 690 * devm_of_platform_populate() - Populate platform_devices from device tree data 691 * @dev: device that requested to populate from device tree data 692 * 693 * Similar to of_platform_populate(), but will automatically call 694 * of_platform_depopulate() when the device is unbound from the bus. 695 * 696 * Return: 0 on success, < 0 on failure. 697 */ 698 int devm_of_platform_populate(struct device *dev) 699 { 700 struct device **ptr; 701 int ret; 702 703 if (!dev) 704 return -EINVAL; 705 706 ptr = devres_alloc(devm_of_platform_populate_release, 707 sizeof(*ptr), GFP_KERNEL); 708 if (!ptr) 709 return -ENOMEM; 710 711 ret = of_platform_populate(dev->of_node, NULL, NULL, dev); 712 if (ret) { 713 devres_free(ptr); 714 } else { 715 *ptr = dev; 716 devres_add(dev, ptr); 717 } 718 719 return ret; 720 } 721 EXPORT_SYMBOL_GPL(devm_of_platform_populate); 722 723 static int devm_of_platform_match(struct device *dev, void *res, void *data) 724 { 725 struct device **ptr = res; 726 727 if (!ptr) { 728 WARN_ON(!ptr); 729 return 0; 730 } 731 732 return *ptr == data; 733 } 734 735 /** 736 * devm_of_platform_depopulate() - Remove devices populated from device tree 737 * @dev: device that requested to depopulate from device tree data 738 * 739 * Complementary to devm_of_platform_populate(), this function removes children 740 * of the given device (and, recurrently, their children) that have been 741 * created from their respective device tree nodes (and only those, 742 * leaving others - eg. manually created - unharmed). 743 */ 744 void devm_of_platform_depopulate(struct device *dev) 745 { 746 int ret; 747 748 ret = devres_release(dev, devm_of_platform_populate_release, 749 devm_of_platform_match, dev); 750 751 WARN_ON(ret); 752 } 753 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate); 754 755 #ifdef CONFIG_OF_DYNAMIC 756 static int of_platform_notify(struct notifier_block *nb, 757 unsigned long action, void *arg) 758 { 759 struct of_reconfig_data *rd = arg; 760 struct platform_device *pdev_parent, *pdev; 761 bool children_left; 762 763 switch (of_reconfig_get_state_change(action, rd)) { 764 case OF_RECONFIG_CHANGE_ADD: 765 /* verify that the parent is a bus */ 766 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS)) 767 return NOTIFY_OK; /* not for us */ 768 769 /* already populated? (driver using of_populate manually) */ 770 if (of_node_check_flag(rd->dn, OF_POPULATED)) 771 return NOTIFY_OK; 772 773 /* 774 * Clear the flag before adding the device so that fw_devlink 775 * doesn't skip adding consumers to this device. 776 */ 777 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE; 778 /* pdev_parent may be NULL when no bus platform device */ 779 pdev_parent = of_find_device_by_node(rd->dn->parent); 780 pdev = of_platform_device_create(rd->dn, NULL, 781 pdev_parent ? &pdev_parent->dev : NULL); 782 platform_device_put(pdev_parent); 783 784 if (pdev == NULL) { 785 pr_err("%s: failed to create for '%pOF'\n", 786 __func__, rd->dn); 787 /* of_platform_device_create tosses the error code */ 788 return notifier_from_errno(-EINVAL); 789 } 790 break; 791 792 case OF_RECONFIG_CHANGE_REMOVE: 793 794 /* already depopulated? */ 795 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 796 return NOTIFY_OK; 797 798 /* find our device by node */ 799 pdev = of_find_device_by_node(rd->dn); 800 if (pdev == NULL) 801 return NOTIFY_OK; /* no? not meant for us */ 802 803 /* unregister takes one ref away */ 804 of_platform_device_destroy(&pdev->dev, &children_left); 805 806 /* and put the reference of the find */ 807 platform_device_put(pdev); 808 break; 809 } 810 811 return NOTIFY_OK; 812 } 813 814 static struct notifier_block platform_of_notifier = { 815 .notifier_call = of_platform_notify, 816 }; 817 818 void of_platform_register_reconfig_notifier(void) 819 { 820 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier)); 821 } 822 #endif /* CONFIG_OF_DYNAMIC */ 823 824 #endif /* CONFIG_OF_ADDRESS */ 825