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
  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 */