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