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