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_irq.h> 23 #include <linux/of_platform.h> 24 #include <linux/platform_device.h> 25 26 const struct of_device_id of_default_bus_match_table[] = { 27 { .compatible = "simple-bus", }, 28 { .compatible = "simple-mfd", }, 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 static void of_dma_deconfigure(struct device *dev) 154 { 155 arch_teardown_dma_ops(dev); 156 } 157 158 /** 159 * of_platform_device_create_pdata - Alloc, initialize and register an of_device 160 * @np: pointer to node to create device for 161 * @bus_id: name to assign device 162 * @platform_data: pointer to populate platform_data pointer with 163 * @parent: Linux device model parent device. 164 * 165 * Returns pointer to created platform device, or NULL if a device was not 166 * registered. Unavailable devices will not get registered. 167 */ 168 static struct platform_device *of_platform_device_create_pdata( 169 struct device_node *np, 170 const char *bus_id, 171 void *platform_data, 172 struct device *parent) 173 { 174 struct platform_device *dev; 175 176 if (!of_device_is_available(np) || 177 of_node_test_and_set_flag(np, OF_POPULATED)) 178 return NULL; 179 180 dev = of_device_alloc(np, bus_id, parent); 181 if (!dev) 182 goto err_clear_flag; 183 184 dev->dev.bus = &platform_bus_type; 185 dev->dev.platform_data = platform_data; 186 of_dma_configure(&dev->dev, dev->dev.of_node); 187 of_msi_configure(&dev->dev, dev->dev.of_node); 188 189 if (of_device_add(dev) != 0) { 190 of_dma_deconfigure(&dev->dev); 191 platform_device_put(dev); 192 goto err_clear_flag; 193 } 194 195 return dev; 196 197 err_clear_flag: 198 of_node_clear_flag(np, OF_POPULATED); 199 return NULL; 200 } 201 202 /** 203 * of_platform_device_create - Alloc, initialize and register an of_device 204 * @np: pointer to node to create device for 205 * @bus_id: name to assign device 206 * @parent: Linux device model parent device. 207 * 208 * Returns pointer to created platform device, or NULL if a device was not 209 * registered. Unavailable devices will not get registered. 210 */ 211 struct platform_device *of_platform_device_create(struct device_node *np, 212 const char *bus_id, 213 struct device *parent) 214 { 215 return of_platform_device_create_pdata(np, bus_id, NULL, parent); 216 } 217 EXPORT_SYMBOL(of_platform_device_create); 218 219 #ifdef CONFIG_ARM_AMBA 220 static struct amba_device *of_amba_device_create(struct device_node *node, 221 const char *bus_id, 222 void *platform_data, 223 struct device *parent) 224 { 225 struct amba_device *dev; 226 const void *prop; 227 int i, ret; 228 229 pr_debug("Creating amba device %s\n", node->full_name); 230 231 if (!of_device_is_available(node) || 232 of_node_test_and_set_flag(node, OF_POPULATED)) 233 return NULL; 234 235 dev = amba_device_alloc(NULL, 0, 0); 236 if (!dev) { 237 pr_err("%s(): amba_device_alloc() failed for %s\n", 238 __func__, node->full_name); 239 goto err_clear_flag; 240 } 241 242 /* setup generic device info */ 243 dev->dev.of_node = of_node_get(node); 244 dev->dev.parent = parent ? : &platform_bus; 245 dev->dev.platform_data = platform_data; 246 if (bus_id) 247 dev_set_name(&dev->dev, "%s", bus_id); 248 else 249 of_device_make_bus_id(&dev->dev); 250 of_dma_configure(&dev->dev, dev->dev.of_node); 251 252 /* Allow the HW Peripheral ID to be overridden */ 253 prop = of_get_property(node, "arm,primecell-periphid", NULL); 254 if (prop) 255 dev->periphid = of_read_ulong(prop, 1); 256 257 /* Decode the IRQs and address ranges */ 258 for (i = 0; i < AMBA_NR_IRQS; i++) 259 dev->irq[i] = irq_of_parse_and_map(node, i); 260 261 ret = of_address_to_resource(node, 0, &dev->res); 262 if (ret) { 263 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n", 264 __func__, ret, node->full_name); 265 goto err_free; 266 } 267 268 ret = amba_device_add(dev, &iomem_resource); 269 if (ret) { 270 pr_err("%s(): amba_device_add() failed (%d) for %s\n", 271 __func__, ret, node->full_name); 272 goto err_free; 273 } 274 275 return dev; 276 277 err_free: 278 amba_device_put(dev); 279 err_clear_flag: 280 of_node_clear_flag(node, OF_POPULATED); 281 return NULL; 282 } 283 #else /* CONFIG_ARM_AMBA */ 284 static struct amba_device *of_amba_device_create(struct device_node *node, 285 const char *bus_id, 286 void *platform_data, 287 struct device *parent) 288 { 289 return NULL; 290 } 291 #endif /* CONFIG_ARM_AMBA */ 292 293 /** 294 * of_devname_lookup() - Given a device node, lookup the preferred Linux name 295 */ 296 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup, 297 struct device_node *np) 298 { 299 struct resource res; 300 301 if (!lookup) 302 return NULL; 303 304 for(; lookup->compatible != NULL; lookup++) { 305 if (!of_device_is_compatible(np, lookup->compatible)) 306 continue; 307 if (!of_address_to_resource(np, 0, &res)) 308 if (res.start != lookup->phys_addr) 309 continue; 310 pr_debug("%s: devname=%s\n", np->full_name, lookup->name); 311 return lookup; 312 } 313 314 return NULL; 315 } 316 317 /** 318 * of_platform_bus_create() - Create a device for a node and its children. 319 * @bus: device node of the bus to instantiate 320 * @matches: match table for bus nodes 321 * @lookup: auxdata table for matching id and platform_data with device nodes 322 * @parent: parent for new device, or NULL for top level. 323 * @strict: require compatible property 324 * 325 * Creates a platform_device for the provided device_node, and optionally 326 * recursively create devices for all the child nodes. 327 */ 328 static int of_platform_bus_create(struct device_node *bus, 329 const struct of_device_id *matches, 330 const struct of_dev_auxdata *lookup, 331 struct device *parent, bool strict) 332 { 333 const struct of_dev_auxdata *auxdata; 334 struct device_node *child; 335 struct platform_device *dev; 336 const char *bus_id = NULL; 337 void *platform_data = NULL; 338 int rc = 0; 339 340 /* Make sure it has a compatible property */ 341 if (strict && (!of_get_property(bus, "compatible", NULL))) { 342 pr_debug("%s() - skipping %s, no compatible prop\n", 343 __func__, bus->full_name); 344 return 0; 345 } 346 347 auxdata = of_dev_lookup(lookup, bus); 348 if (auxdata) { 349 bus_id = auxdata->name; 350 platform_data = auxdata->platform_data; 351 } 352 353 if (of_device_is_compatible(bus, "arm,primecell")) { 354 /* 355 * Don't return an error here to keep compatibility with older 356 * device tree files. 357 */ 358 of_amba_device_create(bus, bus_id, platform_data, parent); 359 return 0; 360 } 361 362 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent); 363 if (!dev || !of_match_node(matches, bus)) 364 return 0; 365 366 for_each_child_of_node(bus, child) { 367 pr_debug(" create child: %s\n", child->full_name); 368 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict); 369 if (rc) { 370 of_node_put(child); 371 break; 372 } 373 } 374 of_node_set_flag(bus, OF_POPULATED_BUS); 375 return rc; 376 } 377 378 /** 379 * of_platform_bus_probe() - Probe the device-tree for platform buses 380 * @root: parent of the first level to probe or NULL for the root of the tree 381 * @matches: match table for bus nodes 382 * @parent: parent to hook devices from, NULL for toplevel 383 * 384 * Note that children of the provided root are not instantiated as devices 385 * unless the specified root itself matches the bus list and is not NULL. 386 */ 387 int of_platform_bus_probe(struct device_node *root, 388 const struct of_device_id *matches, 389 struct device *parent) 390 { 391 struct device_node *child; 392 int rc = 0; 393 394 root = root ? of_node_get(root) : of_find_node_by_path("/"); 395 if (!root) 396 return -EINVAL; 397 398 pr_debug("of_platform_bus_probe()\n"); 399 pr_debug(" starting at: %s\n", root->full_name); 400 401 /* Do a self check of bus type, if there's a match, create children */ 402 if (of_match_node(matches, root)) { 403 rc = of_platform_bus_create(root, matches, NULL, parent, false); 404 } else for_each_child_of_node(root, child) { 405 if (!of_match_node(matches, child)) 406 continue; 407 rc = of_platform_bus_create(child, matches, NULL, parent, false); 408 if (rc) { 409 of_node_put(child); 410 break; 411 } 412 } 413 414 of_node_put(root); 415 return rc; 416 } 417 EXPORT_SYMBOL(of_platform_bus_probe); 418 419 /** 420 * of_platform_populate() - Populate platform_devices from device tree data 421 * @root: parent of the first level to probe or NULL for the root of the tree 422 * @matches: match table, NULL to use the default 423 * @lookup: auxdata table for matching id and platform_data with device nodes 424 * @parent: parent to hook devices from, NULL for toplevel 425 * 426 * Similar to of_platform_bus_probe(), this function walks the device tree 427 * and creates devices from nodes. It differs in that it follows the modern 428 * convention of requiring all device nodes to have a 'compatible' property, 429 * and it is suitable for creating devices which are children of the root 430 * node (of_platform_bus_probe will only create children of the root which 431 * are selected by the @matches argument). 432 * 433 * New board support should be using this function instead of 434 * of_platform_bus_probe(). 435 * 436 * Returns 0 on success, < 0 on failure. 437 */ 438 int of_platform_populate(struct device_node *root, 439 const struct of_device_id *matches, 440 const struct of_dev_auxdata *lookup, 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 for_each_child_of_node(root, child) { 451 rc = of_platform_bus_create(child, matches, lookup, parent, true); 452 if (rc) { 453 of_node_put(child); 454 break; 455 } 456 } 457 of_node_set_flag(root, OF_POPULATED_BUS); 458 459 of_node_put(root); 460 return rc; 461 } 462 EXPORT_SYMBOL_GPL(of_platform_populate); 463 464 int of_platform_default_populate(struct device_node *root, 465 const struct of_dev_auxdata *lookup, 466 struct device *parent) 467 { 468 return of_platform_populate(root, of_default_bus_match_table, lookup, 469 parent); 470 } 471 EXPORT_SYMBOL_GPL(of_platform_default_populate); 472 473 static int of_platform_device_destroy(struct device *dev, void *data) 474 { 475 /* Do not touch devices not populated from the device tree */ 476 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) 477 return 0; 478 479 /* Recurse for any nodes that were treated as busses */ 480 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS)) 481 device_for_each_child(dev, NULL, of_platform_device_destroy); 482 483 if (dev->bus == &platform_bus_type) 484 platform_device_unregister(to_platform_device(dev)); 485 #ifdef CONFIG_ARM_AMBA 486 else if (dev->bus == &amba_bustype) 487 amba_device_unregister(to_amba_device(dev)); 488 #endif 489 490 of_dma_deconfigure(dev); 491 of_node_clear_flag(dev->of_node, OF_POPULATED); 492 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS); 493 return 0; 494 } 495 496 /** 497 * of_platform_depopulate() - Remove devices populated from device tree 498 * @parent: device which children will be removed 499 * 500 * Complementary to of_platform_populate(), this function removes children 501 * of the given device (and, recurrently, their children) that have been 502 * created from their respective device tree nodes (and only those, 503 * leaving others - eg. manually created - unharmed). 504 * 505 * Returns 0 when all children devices have been removed or 506 * -EBUSY when some children remained. 507 */ 508 void of_platform_depopulate(struct device *parent) 509 { 510 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) { 511 device_for_each_child(parent, NULL, of_platform_device_destroy); 512 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS); 513 } 514 } 515 EXPORT_SYMBOL_GPL(of_platform_depopulate); 516 517 #ifdef CONFIG_OF_DYNAMIC 518 static int of_platform_notify(struct notifier_block *nb, 519 unsigned long action, void *arg) 520 { 521 struct of_reconfig_data *rd = arg; 522 struct platform_device *pdev_parent, *pdev; 523 bool children_left; 524 525 switch (of_reconfig_get_state_change(action, rd)) { 526 case OF_RECONFIG_CHANGE_ADD: 527 /* verify that the parent is a bus */ 528 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS)) 529 return NOTIFY_OK; /* not for us */ 530 531 /* already populated? (driver using of_populate manually) */ 532 if (of_node_check_flag(rd->dn, OF_POPULATED)) 533 return NOTIFY_OK; 534 535 /* pdev_parent may be NULL when no bus platform device */ 536 pdev_parent = of_find_device_by_node(rd->dn->parent); 537 pdev = of_platform_device_create(rd->dn, NULL, 538 pdev_parent ? &pdev_parent->dev : NULL); 539 of_dev_put(pdev_parent); 540 541 if (pdev == NULL) { 542 pr_err("%s: failed to create for '%s'\n", 543 __func__, rd->dn->full_name); 544 /* of_platform_device_create tosses the error code */ 545 return notifier_from_errno(-EINVAL); 546 } 547 break; 548 549 case OF_RECONFIG_CHANGE_REMOVE: 550 551 /* already depopulated? */ 552 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 553 return NOTIFY_OK; 554 555 /* find our device by node */ 556 pdev = of_find_device_by_node(rd->dn); 557 if (pdev == NULL) 558 return NOTIFY_OK; /* no? not meant for us */ 559 560 /* unregister takes one ref away */ 561 of_platform_device_destroy(&pdev->dev, &children_left); 562 563 /* and put the reference of the find */ 564 of_dev_put(pdev); 565 break; 566 } 567 568 return NOTIFY_OK; 569 } 570 571 static struct notifier_block platform_of_notifier = { 572 .notifier_call = of_platform_notify, 573 }; 574 575 void of_platform_register_reconfig_notifier(void) 576 { 577 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier)); 578 } 579 #endif /* CONFIG_OF_DYNAMIC */ 580 581 #endif /* CONFIG_OF_ADDRESS */ 582