1 /* 2 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp. 3 * <benh@kernel.crashing.org> 4 * and Arnd Bergmann, IBM Corp. 5 * Merged from powerpc/kernel/of_platform.c and 6 * sparc{,64}/kernel/of_device.c by Stephen Rothwell 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 */ 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/amba/bus.h> 17 #include <linux/device.h> 18 #include <linux/dma-mapping.h> 19 #include <linux/slab.h> 20 #include <linux/of_address.h> 21 #include <linux/of_device.h> 22 #include <linux/of_iommu.h> 23 #include <linux/of_irq.h> 24 #include <linux/of_platform.h> 25 #include <linux/platform_device.h> 26 27 const struct of_device_id of_default_bus_match_table[] = { 28 { .compatible = "simple-bus", }, 29 #ifdef CONFIG_ARM_AMBA 30 { .compatible = "arm,amba-bus", }, 31 #endif /* CONFIG_ARM_AMBA */ 32 {} /* Empty terminated list */ 33 }; 34 35 static int of_dev_node_match(struct device *dev, void *data) 36 { 37 return dev->of_node == data; 38 } 39 40 /** 41 * of_find_device_by_node - Find the platform_device associated with a node 42 * @np: Pointer to device tree node 43 * 44 * Returns platform_device pointer, or NULL if not found 45 */ 46 struct platform_device *of_find_device_by_node(struct device_node *np) 47 { 48 struct device *dev; 49 50 dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match); 51 return dev ? to_platform_device(dev) : NULL; 52 } 53 EXPORT_SYMBOL(of_find_device_by_node); 54 55 #ifdef CONFIG_OF_ADDRESS 56 /* 57 * The following routines scan a subtree and registers a device for 58 * each applicable node. 59 * 60 * Note: sparc doesn't use these routines because it has a different 61 * mechanism for creating devices from device tree nodes. 62 */ 63 64 /** 65 * of_device_make_bus_id - Use the device node data to assign a unique name 66 * @dev: pointer to device structure that is linked to a device tree node 67 * 68 * This routine will first try using the translated bus address to 69 * derive a unique name. If it cannot, then it will prepend names from 70 * parent nodes until a unique name can be derived. 71 */ 72 void of_device_make_bus_id(struct device *dev) 73 { 74 struct device_node *node = dev->of_node; 75 const __be32 *reg; 76 u64 addr; 77 78 /* Construct the name, using parent nodes if necessary to ensure uniqueness */ 79 while (node->parent) { 80 /* 81 * If the address can be translated, then that is as much 82 * uniqueness as we need. Make it the first component and return 83 */ 84 reg = of_get_property(node, "reg", NULL); 85 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) { 86 dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s", 87 (unsigned long long)addr, node->name, 88 dev_name(dev)); 89 return; 90 } 91 92 /* format arguments only used if dev_name() resolves to NULL */ 93 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s", 94 strrchr(node->full_name, '/') + 1, dev_name(dev)); 95 node = node->parent; 96 } 97 } 98 99 /** 100 * of_device_alloc - Allocate and initialize an of_device 101 * @np: device node to assign to device 102 * @bus_id: Name to assign to the device. May be null to use default name. 103 * @parent: Parent device. 104 */ 105 struct platform_device *of_device_alloc(struct device_node *np, 106 const char *bus_id, 107 struct device *parent) 108 { 109 struct platform_device *dev; 110 int rc, i, num_reg = 0, num_irq; 111 struct resource *res, temp_res; 112 113 dev = platform_device_alloc("", -1); 114 if (!dev) 115 return NULL; 116 117 /* count the io and irq resources */ 118 while (of_address_to_resource(np, num_reg, &temp_res) == 0) 119 num_reg++; 120 num_irq = of_irq_count(np); 121 122 /* Populate the resource table */ 123 if (num_irq || num_reg) { 124 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL); 125 if (!res) { 126 platform_device_put(dev); 127 return NULL; 128 } 129 130 dev->num_resources = num_reg + num_irq; 131 dev->resource = res; 132 for (i = 0; i < num_reg; i++, res++) { 133 rc = of_address_to_resource(np, i, res); 134 WARN_ON(rc); 135 } 136 if (of_irq_to_resource_table(np, res, num_irq) != num_irq) 137 pr_debug("not all legacy IRQ resources mapped for %s\n", 138 np->name); 139 } 140 141 dev->dev.of_node = of_node_get(np); 142 dev->dev.parent = parent ? : &platform_bus; 143 144 if (bus_id) 145 dev_set_name(&dev->dev, "%s", bus_id); 146 else 147 of_device_make_bus_id(&dev->dev); 148 149 return dev; 150 } 151 EXPORT_SYMBOL(of_device_alloc); 152 153 /** 154 * of_dma_configure - Setup DMA configuration 155 * @dev: Device to apply DMA configuration 156 * 157 * Try to get devices's DMA configuration from DT and update it 158 * accordingly. 159 * 160 * In case if platform code need to use own special DMA configuration,it 161 * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event 162 * to fix up DMA configuration. 163 */ 164 static void of_dma_configure(struct device *dev) 165 { 166 u64 dma_addr, paddr, size; 167 int ret; 168 bool coherent; 169 unsigned long offset; 170 struct iommu_ops *iommu; 171 172 /* 173 * Set default dma-mask to 32 bit. Drivers are expected to setup 174 * the correct supported dma_mask. 175 */ 176 dev->coherent_dma_mask = DMA_BIT_MASK(32); 177 178 /* 179 * Set it to coherent_dma_mask by default if the architecture 180 * code has not set it. 181 */ 182 if (!dev->dma_mask) 183 dev->dma_mask = &dev->coherent_dma_mask; 184 185 ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); 186 if (ret < 0) { 187 dma_addr = offset = 0; 188 size = dev->coherent_dma_mask; 189 } else { 190 offset = PFN_DOWN(paddr - dma_addr); 191 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset); 192 } 193 dev->dma_pfn_offset = offset; 194 195 coherent = of_dma_is_coherent(dev->of_node); 196 dev_dbg(dev, "device is%sdma coherent\n", 197 coherent ? " " : " not "); 198 199 iommu = of_iommu_configure(dev); 200 dev_dbg(dev, "device is%sbehind an iommu\n", 201 iommu ? " " : " not "); 202 203 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); 204 } 205 206 static void of_dma_deconfigure(struct device *dev) 207 { 208 arch_teardown_dma_ops(dev); 209 } 210 211 /** 212 * of_platform_device_create_pdata - Alloc, initialize and register an of_device 213 * @np: pointer to node to create device for 214 * @bus_id: name to assign device 215 * @platform_data: pointer to populate platform_data pointer with 216 * @parent: Linux device model parent device. 217 * 218 * Returns pointer to created platform device, or NULL if a device was not 219 * registered. Unavailable devices will not get registered. 220 */ 221 static struct platform_device *of_platform_device_create_pdata( 222 struct device_node *np, 223 const char *bus_id, 224 void *platform_data, 225 struct device *parent) 226 { 227 struct platform_device *dev; 228 229 if (!of_device_is_available(np) || 230 of_node_test_and_set_flag(np, OF_POPULATED)) 231 return NULL; 232 233 dev = of_device_alloc(np, bus_id, parent); 234 if (!dev) 235 goto err_clear_flag; 236 237 dev->dev.bus = &platform_bus_type; 238 dev->dev.platform_data = platform_data; 239 of_dma_configure(&dev->dev); 240 241 if (of_device_add(dev) != 0) { 242 of_dma_deconfigure(&dev->dev); 243 platform_device_put(dev); 244 goto err_clear_flag; 245 } 246 247 return dev; 248 249 err_clear_flag: 250 of_node_clear_flag(np, OF_POPULATED); 251 return NULL; 252 } 253 254 /** 255 * of_platform_device_create - Alloc, initialize and register an of_device 256 * @np: pointer to node to create device for 257 * @bus_id: name to assign device 258 * @parent: Linux device model parent device. 259 * 260 * Returns pointer to created platform device, or NULL if a device was not 261 * registered. Unavailable devices will not get registered. 262 */ 263 struct platform_device *of_platform_device_create(struct device_node *np, 264 const char *bus_id, 265 struct device *parent) 266 { 267 return of_platform_device_create_pdata(np, bus_id, NULL, parent); 268 } 269 EXPORT_SYMBOL(of_platform_device_create); 270 271 #ifdef CONFIG_ARM_AMBA 272 static struct amba_device *of_amba_device_create(struct device_node *node, 273 const char *bus_id, 274 void *platform_data, 275 struct device *parent) 276 { 277 struct amba_device *dev; 278 const void *prop; 279 int i, ret; 280 281 pr_debug("Creating amba device %s\n", node->full_name); 282 283 if (!of_device_is_available(node) || 284 of_node_test_and_set_flag(node, OF_POPULATED)) 285 return NULL; 286 287 dev = amba_device_alloc(NULL, 0, 0); 288 if (!dev) { 289 pr_err("%s(): amba_device_alloc() failed for %s\n", 290 __func__, node->full_name); 291 goto err_clear_flag; 292 } 293 294 /* setup generic device info */ 295 dev->dev.of_node = of_node_get(node); 296 dev->dev.parent = parent ? : &platform_bus; 297 dev->dev.platform_data = platform_data; 298 if (bus_id) 299 dev_set_name(&dev->dev, "%s", bus_id); 300 else 301 of_device_make_bus_id(&dev->dev); 302 of_dma_configure(&dev->dev); 303 304 /* Allow the HW Peripheral ID to be overridden */ 305 prop = of_get_property(node, "arm,primecell-periphid", NULL); 306 if (prop) 307 dev->periphid = of_read_ulong(prop, 1); 308 309 /* Decode the IRQs and address ranges */ 310 for (i = 0; i < AMBA_NR_IRQS; i++) 311 dev->irq[i] = irq_of_parse_and_map(node, i); 312 313 ret = of_address_to_resource(node, 0, &dev->res); 314 if (ret) { 315 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n", 316 __func__, ret, node->full_name); 317 goto err_free; 318 } 319 320 ret = amba_device_add(dev, &iomem_resource); 321 if (ret) { 322 pr_err("%s(): amba_device_add() failed (%d) for %s\n", 323 __func__, ret, node->full_name); 324 goto err_free; 325 } 326 327 return dev; 328 329 err_free: 330 amba_device_put(dev); 331 err_clear_flag: 332 of_node_clear_flag(node, OF_POPULATED); 333 return NULL; 334 } 335 #else /* CONFIG_ARM_AMBA */ 336 static struct amba_device *of_amba_device_create(struct device_node *node, 337 const char *bus_id, 338 void *platform_data, 339 struct device *parent) 340 { 341 return NULL; 342 } 343 #endif /* CONFIG_ARM_AMBA */ 344 345 /** 346 * of_devname_lookup() - Given a device node, lookup the preferred Linux name 347 */ 348 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup, 349 struct device_node *np) 350 { 351 struct resource res; 352 353 if (!lookup) 354 return NULL; 355 356 for(; lookup->compatible != NULL; lookup++) { 357 if (!of_device_is_compatible(np, lookup->compatible)) 358 continue; 359 if (!of_address_to_resource(np, 0, &res)) 360 if (res.start != lookup->phys_addr) 361 continue; 362 pr_debug("%s: devname=%s\n", np->full_name, lookup->name); 363 return lookup; 364 } 365 366 return NULL; 367 } 368 369 /** 370 * of_platform_bus_create() - Create a device for a node and its children. 371 * @bus: device node of the bus to instantiate 372 * @matches: match table for bus nodes 373 * @lookup: auxdata table for matching id and platform_data with device nodes 374 * @parent: parent for new device, or NULL for top level. 375 * @strict: require compatible property 376 * 377 * Creates a platform_device for the provided device_node, and optionally 378 * recursively create devices for all the child nodes. 379 */ 380 static int of_platform_bus_create(struct device_node *bus, 381 const struct of_device_id *matches, 382 const struct of_dev_auxdata *lookup, 383 struct device *parent, bool strict) 384 { 385 const struct of_dev_auxdata *auxdata; 386 struct device_node *child; 387 struct platform_device *dev; 388 const char *bus_id = NULL; 389 void *platform_data = NULL; 390 int rc = 0; 391 392 /* Make sure it has a compatible property */ 393 if (strict && (!of_get_property(bus, "compatible", NULL))) { 394 pr_debug("%s() - skipping %s, no compatible prop\n", 395 __func__, bus->full_name); 396 return 0; 397 } 398 399 auxdata = of_dev_lookup(lookup, bus); 400 if (auxdata) { 401 bus_id = auxdata->name; 402 platform_data = auxdata->platform_data; 403 } 404 405 if (of_device_is_compatible(bus, "arm,primecell")) { 406 /* 407 * Don't return an error here to keep compatibility with older 408 * device tree files. 409 */ 410 of_amba_device_create(bus, bus_id, platform_data, parent); 411 return 0; 412 } 413 414 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent); 415 if (!dev || !of_match_node(matches, bus)) 416 return 0; 417 418 for_each_child_of_node(bus, child) { 419 pr_debug(" create child: %s\n", child->full_name); 420 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict); 421 if (rc) { 422 of_node_put(child); 423 break; 424 } 425 } 426 of_node_set_flag(bus, OF_POPULATED_BUS); 427 return rc; 428 } 429 430 /** 431 * of_platform_bus_probe() - Probe the device-tree for platform buses 432 * @root: parent of the first level to probe or NULL for the root of the tree 433 * @matches: match table for bus nodes 434 * @parent: parent to hook devices from, NULL for toplevel 435 * 436 * Note that children of the provided root are not instantiated as devices 437 * unless the specified root itself matches the bus list and is not NULL. 438 */ 439 int of_platform_bus_probe(struct device_node *root, 440 const struct of_device_id *matches, 441 struct device *parent) 442 { 443 struct device_node *child; 444 int rc = 0; 445 446 root = root ? of_node_get(root) : of_find_node_by_path("/"); 447 if (!root) 448 return -EINVAL; 449 450 pr_debug("of_platform_bus_probe()\n"); 451 pr_debug(" starting at: %s\n", root->full_name); 452 453 /* Do a self check of bus type, if there's a match, create children */ 454 if (of_match_node(matches, root)) { 455 rc = of_platform_bus_create(root, matches, NULL, parent, false); 456 } else for_each_child_of_node(root, child) { 457 if (!of_match_node(matches, child)) 458 continue; 459 rc = of_platform_bus_create(child, matches, NULL, parent, false); 460 if (rc) 461 break; 462 } 463 464 of_node_put(root); 465 return rc; 466 } 467 EXPORT_SYMBOL(of_platform_bus_probe); 468 469 /** 470 * of_platform_populate() - Populate platform_devices from device tree data 471 * @root: parent of the first level to probe or NULL for the root of the tree 472 * @matches: match table, NULL to use the default 473 * @lookup: auxdata table for matching id and platform_data with device nodes 474 * @parent: parent to hook devices from, NULL for toplevel 475 * 476 * Similar to of_platform_bus_probe(), this function walks the device tree 477 * and creates devices from nodes. It differs in that it follows the modern 478 * convention of requiring all device nodes to have a 'compatible' property, 479 * and it is suitable for creating devices which are children of the root 480 * node (of_platform_bus_probe will only create children of the root which 481 * are selected by the @matches argument). 482 * 483 * New board support should be using this function instead of 484 * of_platform_bus_probe(). 485 * 486 * Returns 0 on success, < 0 on failure. 487 */ 488 int of_platform_populate(struct device_node *root, 489 const struct of_device_id *matches, 490 const struct of_dev_auxdata *lookup, 491 struct device *parent) 492 { 493 struct device_node *child; 494 int rc = 0; 495 496 root = root ? of_node_get(root) : of_find_node_by_path("/"); 497 if (!root) 498 return -EINVAL; 499 500 for_each_child_of_node(root, child) { 501 rc = of_platform_bus_create(child, matches, lookup, parent, true); 502 if (rc) 503 break; 504 } 505 of_node_set_flag(root, OF_POPULATED_BUS); 506 507 of_node_put(root); 508 return rc; 509 } 510 EXPORT_SYMBOL_GPL(of_platform_populate); 511 512 static int of_platform_device_destroy(struct device *dev, void *data) 513 { 514 /* Do not touch devices not populated from the device tree */ 515 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) 516 return 0; 517 518 /* Recurse for any nodes that were treated as busses */ 519 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS)) 520 device_for_each_child(dev, NULL, of_platform_device_destroy); 521 522 if (dev->bus == &platform_bus_type) 523 platform_device_unregister(to_platform_device(dev)); 524 #ifdef CONFIG_ARM_AMBA 525 else if (dev->bus == &amba_bustype) 526 amba_device_unregister(to_amba_device(dev)); 527 #endif 528 529 of_dma_deconfigure(dev); 530 of_node_clear_flag(dev->of_node, OF_POPULATED); 531 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS); 532 return 0; 533 } 534 535 /** 536 * of_platform_depopulate() - Remove devices populated from device tree 537 * @parent: device which children will be removed 538 * 539 * Complementary to of_platform_populate(), this function removes children 540 * of the given device (and, recurrently, their children) that have been 541 * created from their respective device tree nodes (and only those, 542 * leaving others - eg. manually created - unharmed). 543 * 544 * Returns 0 when all children devices have been removed or 545 * -EBUSY when some children remained. 546 */ 547 void of_platform_depopulate(struct device *parent) 548 { 549 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) { 550 device_for_each_child(parent, NULL, of_platform_device_destroy); 551 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS); 552 } 553 } 554 EXPORT_SYMBOL_GPL(of_platform_depopulate); 555 556 #ifdef CONFIG_OF_DYNAMIC 557 static int of_platform_notify(struct notifier_block *nb, 558 unsigned long action, void *arg) 559 { 560 struct of_reconfig_data *rd = arg; 561 struct platform_device *pdev_parent, *pdev; 562 bool children_left; 563 564 switch (of_reconfig_get_state_change(action, rd)) { 565 case OF_RECONFIG_CHANGE_ADD: 566 /* verify that the parent is a bus */ 567 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS)) 568 return NOTIFY_OK; /* not for us */ 569 570 /* already populated? (driver using of_populate manually) */ 571 if (of_node_check_flag(rd->dn, OF_POPULATED)) 572 return NOTIFY_OK; 573 574 /* pdev_parent may be NULL when no bus platform device */ 575 pdev_parent = of_find_device_by_node(rd->dn->parent); 576 pdev = of_platform_device_create(rd->dn, NULL, 577 pdev_parent ? &pdev_parent->dev : NULL); 578 of_dev_put(pdev_parent); 579 580 if (pdev == NULL) { 581 pr_err("%s: failed to create for '%s'\n", 582 __func__, rd->dn->full_name); 583 /* of_platform_device_create tosses the error code */ 584 return notifier_from_errno(-EINVAL); 585 } 586 break; 587 588 case OF_RECONFIG_CHANGE_REMOVE: 589 590 /* already depopulated? */ 591 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 592 return NOTIFY_OK; 593 594 /* find our device by node */ 595 pdev = of_find_device_by_node(rd->dn); 596 if (pdev == NULL) 597 return NOTIFY_OK; /* no? not meant for us */ 598 599 /* unregister takes one ref away */ 600 of_platform_device_destroy(&pdev->dev, &children_left); 601 602 /* and put the reference of the find */ 603 of_dev_put(pdev); 604 break; 605 } 606 607 return NOTIFY_OK; 608 } 609 610 static struct notifier_block platform_of_notifier = { 611 .notifier_call = of_platform_notify, 612 }; 613 614 void of_platform_register_reconfig_notifier(void) 615 { 616 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier)); 617 } 618 #endif /* CONFIG_OF_DYNAMIC */ 619 620 #endif /* CONFIG_OF_ADDRESS */ 621