drivers/of/platform.c

   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
  15 #define pr_fmt(fmt)     "OF: " fmt
  16
  17 #include <linux/errno.h>
  18 #include <linux/module.h>
  19 #include <linux/amba/bus.h>
  20 #include <linux/device.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/slab.h>
  23 #include <linux/of_address.h>
  24 #include <linux/of_device.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/of_platform.h>
  27 #include <linux/platform_device.h>
  28
  29 const struct of_device_id of_default_bus_match_table[] = {
  30         { .compatible = "simple-bus", },
  31         { .compatible = "simple-mfd", },
  32 #ifdef CONFIG_ARM_AMBA
  33         { .compatible = "arm,amba-bus", },
  34 #endif /* CONFIG_ARM_AMBA */
  35         {} /* Empty terminated list */
  36 };
  37
  38 static int of_dev_node_match(struct device *dev, void *data)
  39 {
  40         return dev->of_node == data;
  41 }
  42
  43 /**
  44  * of_find_device_by_node - Find the platform_device associated with a node
  45  * @np: Pointer to device tree node
  46  *
  47  * Returns platform_device pointer, or NULL if not found
  48  */
  49 struct platform_device *of_find_device_by_node(struct device_node *np)
  50 {
  51         struct device *dev;
  52
  53         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  54         return dev ? to_platform_device(dev) : NULL;
  55 }
  56 EXPORT_SYMBOL(of_find_device_by_node);
  57
  58 #ifdef CONFIG_OF_ADDRESS
  59 /*
  60  * The following routines scan a subtree and registers a device for
  61  * each applicable node.
  62  *
  63  * Note: sparc doesn't use these routines because it has a different
  64  * mechanism for creating devices from device tree nodes.
  65  */
  66
  67 /**
  68  * of_device_make_bus_id - Use the device node data to assign a unique name
  69  * @dev: pointer to device structure that is linked to a device tree node
  70  *
  71  * This routine will first try using the translated bus address to
  72  * derive a unique name. If it cannot, then it will prepend names from
  73  * parent nodes until a unique name can be derived.
  74  */
  75 void of_device_make_bus_id(struct device *dev)
  76 {
  77         struct device_node *node = dev->of_node;
  78         const __be32 *reg;
  79         u64 addr;
  80
  81         /* Construct the name, using parent nodes if necessary to ensure uniqueness */
  82         while (node->parent) {
  83                 /*
  84                  * If the address can be translated, then that is as much
  85                  * uniqueness as we need. Make it the first component and return
  86                  */
  87                 reg = of_get_property(node, "reg", NULL);
  88                 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
  89                         dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
  90                                      (unsigned long long)addr, node->name,
  91                                      dev_name(dev));
  92                         return;
  93                 }
  94
  95                 /* format arguments only used if dev_name() resolves to NULL */
  96                 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
  97                              strrchr(node->full_name, '/') + 1, dev_name(dev));
  98                 node = node->parent;
  99         }
 100 }
 101
 102 /**
 103  * of_device_alloc - Allocate and initialize an of_device
 104  * @np: device node to assign to device
 105  * @bus_id: Name to assign to the device.  May be null to use default name.
 106  * @parent: Parent device.
 107  */
 108 struct platform_device *of_device_alloc(struct device_node *np,
 109                                   const char *bus_id,
 110                                   struct device *parent)
 111 {
 112         struct platform_device *dev;
 113         int rc, i, num_reg = 0, num_irq;
 114         struct resource *res, temp_res;
 115
 116         dev = platform_device_alloc("", -1);
 117         if (!dev)
 118                 return NULL;
 119
 120         /* count the io and irq resources */
 121         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 122                 num_reg++;
 123         num_irq = of_irq_count(np);
 124
 125         /* Populate the resource table */
 126         if (num_irq || num_reg) {
 127                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 128                 if (!res) {
 129                         platform_device_put(dev);
 130                         return NULL;
 131                 }
 132
 133                 dev->num_resources = num_reg + num_irq;
 134                 dev->resource = res;
 135                 for (i = 0; i < num_reg; i++, res++) {
 136                         rc = of_address_to_resource(np, i, res);
 137                         WARN_ON(rc);
 138                 }
 139                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
 140                         pr_debug("not all legacy IRQ resources mapped for %s\n",
 141                                  np->name);
 142         }
 143
 144         dev->dev.of_node = of_node_get(np);
 145         dev->dev.parent = parent ? : &platform_bus;
 146
 147         if (bus_id)
 148                 dev_set_name(&dev->dev, "%s", bus_id);
 149         else
 150                 of_device_make_bus_id(&dev->dev);
 151
 152         return dev;
 153 }
 154 EXPORT_SYMBOL(of_device_alloc);
 155
 156 static void of_dma_deconfigure(struct device *dev)
 157 {
 158         arch_teardown_dma_ops(dev);
 159 }
 160
 161 /**
 162  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 163  * @np: pointer to node to create device for
 164  * @bus_id: name to assign device
 165  * @platform_data: pointer to populate platform_data pointer with
 166  * @parent: Linux device model parent device.
 167  *
 168  * Returns pointer to created platform device, or NULL if a device was not
 169  * registered.  Unavailable devices will not get registered.
 170  */
 171 static struct platform_device *of_platform_device_create_pdata(
 172                                         struct device_node *np,
 173                                         const char *bus_id,
 174                                         void *platform_data,
 175                                         struct device *parent)
 176 {
 177         struct platform_device *dev;
 178
 179         if (!of_device_is_available(np) ||
 180             of_node_test_and_set_flag(np, OF_POPULATED))
 181                 return NULL;
 182
 183         dev = of_device_alloc(np, bus_id, parent);
 184         if (!dev)
 185                 goto err_clear_flag;
 186
 187         dev->dev.bus = &platform_bus_type;
 188         dev->dev.platform_data = platform_data;
 189         of_dma_configure(&dev->dev, dev->dev.of_node);
 190         of_msi_configure(&dev->dev, dev->dev.of_node);
 191
 192         if (of_device_add(dev) != 0) {
 193                 of_dma_deconfigure(&dev->dev);
 194                 platform_device_put(dev);
 195                 goto err_clear_flag;
 196         }
 197
 198         return dev;
 199
 200 err_clear_flag:
 201         of_node_clear_flag(np, OF_POPULATED);
 202         return NULL;
 203 }
 204
 205 /**
 206  * of_platform_device_create - Alloc, initialize and register an of_device
 207  * @np: pointer to node to create device for
 208  * @bus_id: name to assign device
 209  * @parent: Linux device model parent device.
 210  *
 211  * Returns pointer to created platform device, or NULL if a device was not
 212  * registered.  Unavailable devices will not get registered.
 213  */
 214 struct platform_device *of_platform_device_create(struct device_node *np,
 215                                             const char *bus_id,
 216                                             struct device *parent)
 217 {
 218         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 219 }
 220 EXPORT_SYMBOL(of_platform_device_create);
 221
 222 #ifdef CONFIG_ARM_AMBA
 223 static struct amba_device *of_amba_device_create(struct device_node *node,
 224                                                  const char *bus_id,
 225                                                  void *platform_data,
 226                                                  struct device *parent)
 227 {
 228         struct amba_device *dev;
 229         const void *prop;
 230         int i, ret;
 231
 232         pr_debug("Creating amba device %s\n", node->full_name);
 233
 234         if (!of_device_is_available(node) ||
 235             of_node_test_and_set_flag(node, OF_POPULATED))
 236                 return NULL;
 237
 238         dev = amba_device_alloc(NULL, 0, 0);
 239         if (!dev)
 240                 goto err_clear_flag;
 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("amba: of_address_to_resource() failed (%d) for %s\n",
 264                        ret, node->full_name);
 265                 goto err_free;
 266         }
 267
 268         ret = amba_device_add(dev, &iomem_resource);
 269         if (ret) {
 270                 pr_err("amba_device_add() failed (%d) for %s\n",
 271                        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         const struct of_dev_auxdata *auxdata;
 300         struct resource res;
 301         int compatible = 0;
 302
 303         if (!lookup)
 304                 return NULL;
 305
 306         auxdata = lookup;
 307         for (; auxdata->compatible; auxdata++) {
 308                 if (!of_device_is_compatible(np, auxdata->compatible))
 309                         continue;
 310                 compatible++;
 311                 if (!of_address_to_resource(np, 0, &res))
 312                         if (res.start != auxdata->phys_addr)
 313                                 continue;
 314                 pr_debug("%s: devname=%s\n", np->full_name, auxdata->name);
 315                 return auxdata;
 316         }
 317
 318         if (!compatible)
 319                 return NULL;
 320
 321         /* Try compatible match if no phys_addr and name are specified */
 322         auxdata = lookup;
 323         for (; auxdata->compatible; auxdata++) {
 324                 if (!of_device_is_compatible(np, auxdata->compatible))
 325                         continue;
 326                 if (!auxdata->phys_addr && !auxdata->name) {
 327                         pr_debug("%s: compatible match\n", np->full_name);
 328                         return auxdata;
 329                 }
 330         }
 331
 332         return NULL;
 333 }
 334
 335 /**
 336  * of_platform_bus_create() - Create a device for a node and its children.
 337  * @bus: device node of the bus to instantiate
 338  * @matches: match table for bus nodes
 339  * @lookup: auxdata table for matching id and platform_data with device nodes
 340  * @parent: parent for new device, or NULL for top level.
 341  * @strict: require compatible property
 342  *
 343  * Creates a platform_device for the provided device_node, and optionally
 344  * recursively create devices for all the child nodes.
 345  */
 346 static int of_platform_bus_create(struct device_node *bus,
 347                                   const struct of_device_id *matches,
 348                                   const struct of_dev_auxdata *lookup,
 349                                   struct device *parent, bool strict)
 350 {
 351         const struct of_dev_auxdata *auxdata;
 352         struct device_node *child;
 353         struct platform_device *dev;
 354         const char *bus_id = NULL;
 355         void *platform_data = NULL;
 356         int rc = 0;
 357
 358         /* Make sure it has a compatible property */
 359         if (strict && (!of_get_property(bus, "compatible", NULL))) {
 360                 pr_debug("%s() - skipping %s, no compatible prop\n",
 361                          __func__, bus->full_name);
 362                 return 0;
 363         }
 364
 365         if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
 366                 pr_debug("%s() - skipping %s, already populated\n",
 367                         __func__, bus->full_name);
 368                 return 0;
 369         }
 370
 371         auxdata = of_dev_lookup(lookup, bus);
 372         if (auxdata) {
 373                 bus_id = auxdata->name;
 374                 platform_data = auxdata->platform_data;
 375         }
 376
 377         if (of_device_is_compatible(bus, "arm,primecell")) {
 378                 /*
 379                  * Don't return an error here to keep compatibility with older
 380                  * device tree files.
 381                  */
 382                 of_amba_device_create(bus, bus_id, platform_data, parent);
 383                 return 0;
 384         }
 385
 386         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 387         if (!dev || !of_match_node(matches, bus))
 388                 return 0;
 389
 390         for_each_child_of_node(bus, child) {
 391                 pr_debug("   create child: %s\n", child->full_name);
 392                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 393                 if (rc) {
 394                         of_node_put(child);
 395                         break;
 396                 }
 397         }
 398         of_node_set_flag(bus, OF_POPULATED_BUS);
 399         return rc;
 400 }
 401
 402 /**
 403  * of_platform_bus_probe() - Probe the device-tree for platform buses
 404  * @root: parent of the first level to probe or NULL for the root of the tree
 405  * @matches: match table for bus nodes
 406  * @parent: parent to hook devices from, NULL for toplevel
 407  *
 408  * Note that children of the provided root are not instantiated as devices
 409  * unless the specified root itself matches the bus list and is not NULL.
 410  */
 411 int of_platform_bus_probe(struct device_node *root,
 412                           const struct of_device_id *matches,
 413                           struct device *parent)
 414 {
 415         struct device_node *child;
 416         int rc = 0;
 417
 418         root = root ? of_node_get(root) : of_find_node_by_path("/");
 419         if (!root)
 420                 return -EINVAL;
 421
 422         pr_debug("%s()\n", __func__);
 423         pr_debug(" starting at: %s\n", root->full_name);
 424
 425         /* Do a self check of bus type, if there's a match, create children */
 426         if (of_match_node(matches, root)) {
 427                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
 428         } else for_each_child_of_node(root, child) {
 429                 if (!of_match_node(matches, child))
 430                         continue;
 431                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
 432                 if (rc) {
 433                         of_node_put(child);
 434                         break;
 435                 }
 436         }
 437
 438         of_node_put(root);
 439         return rc;
 440 }
 441 EXPORT_SYMBOL(of_platform_bus_probe);
 442
 443 /**
 444  * of_platform_populate() - Populate platform_devices from device tree data
 445  * @root: parent of the first level to probe or NULL for the root of the tree
 446  * @matches: match table, NULL to use the default
 447  * @lookup: auxdata table for matching id and platform_data with device nodes
 448  * @parent: parent to hook devices from, NULL for toplevel
 449  *
 450  * Similar to of_platform_bus_probe(), this function walks the device tree
 451  * and creates devices from nodes.  It differs in that it follows the modern
 452  * convention of requiring all device nodes to have a 'compatible' property,
 453  * and it is suitable for creating devices which are children of the root
 454  * node (of_platform_bus_probe will only create children of the root which
 455  * are selected by the @matches argument).
 456  *
 457  * New board support should be using this function instead of
 458  * of_platform_bus_probe().
 459  *
 460  * Returns 0 on success, < 0 on failure.
 461  */
 462 int of_platform_populate(struct device_node *root,
 463                         const struct of_device_id *matches,
 464                         const struct of_dev_auxdata *lookup,
 465                         struct device *parent)
 466 {
 467         struct device_node *child;
 468         int rc = 0;
 469
 470         root = root ? of_node_get(root) : of_find_node_by_path("/");
 471         if (!root)
 472                 return -EINVAL;
 473
 474         pr_debug("%s()\n", __func__);
 475         pr_debug(" starting at: %s\n", root->full_name);
 476
 477         for_each_child_of_node(root, child) {
 478                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
 479                 if (rc) {
 480                         of_node_put(child);
 481                         break;
 482                 }
 483         }
 484         of_node_set_flag(root, OF_POPULATED_BUS);
 485
 486         of_node_put(root);
 487         return rc;
 488 }
 489 EXPORT_SYMBOL_GPL(of_platform_populate);
 490
 491 int of_platform_default_populate(struct device_node *root,
 492                                  const struct of_dev_auxdata *lookup,
 493                                  struct device *parent)
 494 {
 495         return of_platform_populate(root, of_default_bus_match_table, lookup,
 496                                     parent);
 497 }
 498 EXPORT_SYMBOL_GPL(of_platform_default_populate);
 499
 500 #ifndef CONFIG_PPC
 501 static int __init of_platform_default_populate_init(void)
 502 {
 503         struct device_node *node;
 504
 505         if (!of_have_populated_dt())
 506                 return -ENODEV;
 507
 508         /*
 509          * Handle ramoops explicitly, since it is inside /reserved-memory,
 510          * which lacks a "compatible" property.
 511          */
 512         node = of_find_node_by_path("/reserved-memory");
 513         if (node) {
 514                 node = of_find_compatible_node(node, NULL, "ramoops");
 515                 if (node)
 516                         of_platform_device_create(node, NULL, NULL);
 517         }
 518
 519         /* Populate everything else. */
 520         of_platform_default_populate(NULL, NULL, NULL);
 521
 522         return 0;
 523 }
 524 arch_initcall_sync(of_platform_default_populate_init);
 525 #endif
 526
 527 static int of_platform_device_destroy(struct device *dev, void *data)
 528 {
 529         /* Do not touch devices not populated from the device tree */
 530         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
 531                 return 0;
 532
 533         /* Recurse for any nodes that were treated as busses */
 534         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
 535                 device_for_each_child(dev, NULL, of_platform_device_destroy);
 536
 537         if (dev->bus == &platform_bus_type)
 538                 platform_device_unregister(to_platform_device(dev));
 539 #ifdef CONFIG_ARM_AMBA
 540         else if (dev->bus == &amba_bustype)
 541                 amba_device_unregister(to_amba_device(dev));
 542 #endif
 543
 544         of_dma_deconfigure(dev);
 545         of_node_clear_flag(dev->of_node, OF_POPULATED);
 546         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 547         return 0;
 548 }
 549
 550 /**
 551  * of_platform_depopulate() - Remove devices populated from device tree
 552  * @parent: device which children will be removed
 553  *
 554  * Complementary to of_platform_populate(), this function removes children
 555  * of the given device (and, recurrently, their children) that have been
 556  * created from their respective device tree nodes (and only those,
 557  * leaving others - eg. manually created - unharmed).
 558  *
 559  * Returns 0 when all children devices have been removed or
 560  * -EBUSY when some children remained.
 561  */
 562 void of_platform_depopulate(struct device *parent)
 563 {
 564         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
 565                 device_for_each_child(parent, NULL, of_platform_device_destroy);
 566                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
 567         }
 568 }
 569 EXPORT_SYMBOL_GPL(of_platform_depopulate);
 570
 571 #ifdef CONFIG_OF_DYNAMIC
 572 static int of_platform_notify(struct notifier_block *nb,
 573                                 unsigned long action, void *arg)
 574 {
 575         struct of_reconfig_data *rd = arg;
 576         struct platform_device *pdev_parent, *pdev;
 577         bool children_left;
 578
 579         switch (of_reconfig_get_state_change(action, rd)) {
 580         case OF_RECONFIG_CHANGE_ADD:
 581                 /* verify that the parent is a bus */
 582                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
 583                         return NOTIFY_OK;       /* not for us */
 584
 585                 /* already populated? (driver using of_populate manually) */
 586                 if (of_node_check_flag(rd->dn, OF_POPULATED))
 587                         return NOTIFY_OK;
 588
 589                 /* pdev_parent may be NULL when no bus platform device */
 590                 pdev_parent = of_find_device_by_node(rd->dn->parent);
 591                 pdev = of_platform_device_create(rd->dn, NULL,
 592                                 pdev_parent ? &pdev_parent->dev : NULL);
 593                 of_dev_put(pdev_parent);
 594
 595                 if (pdev == NULL) {
 596                         pr_err("%s: failed to create for '%s'\n",
 597                                         __func__, rd->dn->full_name);
 598                         /* of_platform_device_create tosses the error code */
 599                         return notifier_from_errno(-EINVAL);
 600                 }
 601                 break;
 602
 603         case OF_RECONFIG_CHANGE_REMOVE:
 604
 605                 /* already depopulated? */
 606                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
 607                         return NOTIFY_OK;
 608
 609                 /* find our device by node */
 610                 pdev = of_find_device_by_node(rd->dn);
 611                 if (pdev == NULL)
 612                         return NOTIFY_OK;       /* no? not meant for us */
 613
 614                 /* unregister takes one ref away */
 615                 of_platform_device_destroy(&pdev->dev, &children_left);
 616
 617                 /* and put the reference of the find */
 618                 of_dev_put(pdev);
 619                 break;
 620         }
 621
 622         return NOTIFY_OK;
 623 }
 624
 625 static struct notifier_block platform_of_notifier = {
 626         .notifier_call = of_platform_notify,
 627 };
 628
 629 void of_platform_register_reconfig_notifier(void)
 630 {
 631         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
 632 }
 633 #endif /* CONFIG_OF_DYNAMIC */
 634
 635 #endif /* CONFIG_OF_ADDRESS */