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         { .compatible = "isa", },
  33 #ifdef CONFIG_ARM_AMBA
  34         { .compatible = "arm,amba-bus", },
  35 #endif /* CONFIG_ARM_AMBA */
  36         {} /* Empty terminated list */
  37 };
  38
  39 static int of_dev_node_match(struct device *dev, void *data)
  40 {
  41         return dev->of_node == data;
  42 }
  43
  44 /**
  45  * of_find_device_by_node - Find the platform_device associated with a node
  46  * @np: Pointer to device tree node
  47  *
  48  * Returns platform_device pointer, or NULL if not found
  49  */
  50 struct platform_device *of_find_device_by_node(struct device_node *np)
  51 {
  52         struct device *dev;
  53
  54         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  55         return dev ? to_platform_device(dev) : NULL;
  56 }
  57 EXPORT_SYMBOL(of_find_device_by_node);
  58
  59 #ifdef CONFIG_OF_ADDRESS
  60 /*
  61  * The following routines scan a subtree and registers a device for
  62  * each applicable node.
  63  *
  64  * Note: sparc doesn't use these routines because it has a different
  65  * mechanism for creating devices from device tree nodes.
  66  */
  67
  68 /**
  69  * of_device_make_bus_id - Use the device node data to assign a unique name
  70  * @dev: pointer to device structure that is linked to a device tree node
  71  *
  72  * This routine will first try using the translated bus address to
  73  * derive a unique name. If it cannot, then it will prepend names from
  74  * parent nodes until a unique name can be derived.
  75  */
  76 void of_device_make_bus_id(struct device *dev)
  77 {
  78         struct device_node *node = dev->of_node;
  79         const __be32 *reg;
  80         u64 addr;
  81
  82         /* Construct the name, using parent nodes if necessary to ensure uniqueness */
  83         while (node->parent) {
  84                 /*
  85                  * If the address can be translated, then that is as much
  86                  * uniqueness as we need. Make it the first component and return
  87                  */
  88                 reg = of_get_property(node, "reg", NULL);
  89                 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
  90                         dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
  91                                      (unsigned long long)addr, node->name,
  92                                      dev_name(dev));
  93                         return;
  94                 }
  95
  96                 /* format arguments only used if dev_name() resolves to NULL */
  97                 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
  98                              strrchr(node->full_name, '/') + 1, dev_name(dev));
  99                 node = node->parent;
 100         }
 101 }
 102
 103 /**
 104  * of_device_alloc - Allocate and initialize an of_device
 105  * @np: device node to assign to device
 106  * @bus_id: Name to assign to the device.  May be null to use default name.
 107  * @parent: Parent device.
 108  */
 109 struct platform_device *of_device_alloc(struct device_node *np,
 110                                   const char *bus_id,
 111                                   struct device *parent)
 112 {
 113         struct platform_device *dev;
 114         int rc, i, num_reg = 0, num_irq;
 115         struct resource *res, temp_res;
 116
 117         dev = platform_device_alloc("", -1);
 118         if (!dev)
 119                 return NULL;
 120
 121         /* count the io and irq resources */
 122         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 123                 num_reg++;
 124         num_irq = of_irq_count(np);
 125
 126         /* Populate the resource table */
 127         if (num_irq || num_reg) {
 128                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 129                 if (!res) {
 130                         platform_device_put(dev);
 131                         return NULL;
 132                 }
 133
 134                 dev->num_resources = num_reg + num_irq;
 135                 dev->resource = res;
 136                 for (i = 0; i < num_reg; i++, res++) {
 137                         rc = of_address_to_resource(np, i, res);
 138                         WARN_ON(rc);
 139                 }
 140                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
 141                         pr_debug("not all legacy IRQ resources mapped for %s\n",
 142                                  np->name);
 143         }
 144
 145         dev->dev.of_node = of_node_get(np);
 146         dev->dev.fwnode = &np->fwnode;
 147         dev->dev.parent = parent ? : &platform_bus;
 148
 149         if (bus_id)
 150                 dev_set_name(&dev->dev, "%s", bus_id);
 151         else
 152                 of_device_make_bus_id(&dev->dev);
 153
 154         return dev;
 155 }
 156 EXPORT_SYMBOL(of_device_alloc);
 157
 158 static void of_dma_deconfigure(struct device *dev)
 159 {
 160         arch_teardown_dma_ops(dev);
 161 }
 162
 163 /**
 164  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 165  * @np: pointer to node to create device for
 166  * @bus_id: name to assign device
 167  * @platform_data: pointer to populate platform_data pointer with
 168  * @parent: Linux device model parent device.
 169  *
 170  * Returns pointer to created platform device, or NULL if a device was not
 171  * registered.  Unavailable devices will not get registered.
 172  */
 173 static struct platform_device *of_platform_device_create_pdata(
 174                                         struct device_node *np,
 175                                         const char *bus_id,
 176                                         void *platform_data,
 177                                         struct device *parent)
 178 {
 179         struct platform_device *dev;
 180
 181         if (!of_device_is_available(np) ||
 182             of_node_test_and_set_flag(np, OF_POPULATED))
 183                 return NULL;
 184
 185         dev = of_device_alloc(np, bus_id, parent);
 186         if (!dev)
 187                 goto err_clear_flag;
 188
 189         dev->dev.bus = &platform_bus_type;
 190         dev->dev.platform_data = platform_data;
 191         of_dma_configure(&dev->dev, dev->dev.of_node);
 192         of_msi_configure(&dev->dev, dev->dev.of_node);
 193
 194         if (of_device_add(dev) != 0) {
 195                 of_dma_deconfigure(&dev->dev);
 196                 platform_device_put(dev);
 197                 goto err_clear_flag;
 198         }
 199
 200         return dev;
 201
 202 err_clear_flag:
 203         of_node_clear_flag(np, OF_POPULATED);
 204         return NULL;
 205 }
 206
 207 /**
 208  * of_platform_device_create - Alloc, initialize and register an of_device
 209  * @np: pointer to node to create device for
 210  * @bus_id: name to assign device
 211  * @parent: Linux device model parent device.
 212  *
 213  * Returns pointer to created platform device, or NULL if a device was not
 214  * registered.  Unavailable devices will not get registered.
 215  */
 216 struct platform_device *of_platform_device_create(struct device_node *np,
 217                                             const char *bus_id,
 218                                             struct device *parent)
 219 {
 220         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 221 }
 222 EXPORT_SYMBOL(of_platform_device_create);
 223
 224 #ifdef CONFIG_ARM_AMBA
 225 static struct amba_device *of_amba_device_create(struct device_node *node,
 226                                                  const char *bus_id,
 227                                                  void *platform_data,
 228                                                  struct device *parent)
 229 {
 230         struct amba_device *dev;
 231         const void *prop;
 232         int i, ret;
 233
 234         pr_debug("Creating amba device %s\n", node->full_name);
 235
 236         if (!of_device_is_available(node) ||
 237             of_node_test_and_set_flag(node, OF_POPULATED))
 238                 return NULL;
 239
 240         dev = amba_device_alloc(NULL, 0, 0);
 241         if (!dev)
 242                 goto err_clear_flag;
 243
 244         /* setup generic device info */
 245         dev->dev.of_node = of_node_get(node);
 246         dev->dev.fwnode = &node->fwnode;
 247         dev->dev.parent = parent ? : &platform_bus;
 248         dev->dev.platform_data = platform_data;
 249         if (bus_id)
 250                 dev_set_name(&dev->dev, "%s", bus_id);
 251         else
 252                 of_device_make_bus_id(&dev->dev);
 253         of_dma_configure(&dev->dev, dev->dev.of_node);
 254
 255         /* Allow the HW Peripheral ID to be overridden */
 256         prop = of_get_property(node, "arm,primecell-periphid", NULL);
 257         if (prop)
 258                 dev->periphid = of_read_ulong(prop, 1);
 259
 260         /* Decode the IRQs and address ranges */
 261         for (i = 0; i < AMBA_NR_IRQS; i++)
 262                 dev->irq[i] = irq_of_parse_and_map(node, i);
 263
 264         ret = of_address_to_resource(node, 0, &dev->res);
 265         if (ret) {
 266                 pr_err("amba: of_address_to_resource() failed (%d) for %s\n",
 267                        ret, node->full_name);
 268                 goto err_free;
 269         }
 270
 271         ret = amba_device_add(dev, &iomem_resource);
 272         if (ret) {
 273                 pr_err("amba_device_add() failed (%d) for %s\n",
 274                        ret, node->full_name);
 275                 goto err_free;
 276         }
 277
 278         return dev;
 279
 280 err_free:
 281         amba_device_put(dev);
 282 err_clear_flag:
 283         of_node_clear_flag(node, OF_POPULATED);
 284         return NULL;
 285 }
 286 #else /* CONFIG_ARM_AMBA */
 287 static struct amba_device *of_amba_device_create(struct device_node *node,
 288                                                  const char *bus_id,
 289                                                  void *platform_data,
 290                                                  struct device *parent)
 291 {
 292         return NULL;
 293 }
 294 #endif /* CONFIG_ARM_AMBA */
 295
 296 /**
 297  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 298  */
 299 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 300                                  struct device_node *np)
 301 {
 302         const struct of_dev_auxdata *auxdata;
 303         struct resource res;
 304         int compatible = 0;
 305
 306         if (!lookup)
 307                 return NULL;
 308
 309         auxdata = lookup;
 310         for (; auxdata->compatible; auxdata++) {
 311                 if (!of_device_is_compatible(np, auxdata->compatible))
 312                         continue;
 313                 compatible++;
 314                 if (!of_address_to_resource(np, 0, &res))
 315                         if (res.start != auxdata->phys_addr)
 316                                 continue;
 317                 pr_debug("%s: devname=%s\n", np->full_name, auxdata->name);
 318                 return auxdata;
 319         }
 320
 321         if (!compatible)
 322                 return NULL;
 323
 324         /* Try compatible match if no phys_addr and name are specified */
 325         auxdata = lookup;
 326         for (; auxdata->compatible; auxdata++) {
 327                 if (!of_device_is_compatible(np, auxdata->compatible))
 328                         continue;
 329                 if (!auxdata->phys_addr && !auxdata->name) {
 330                         pr_debug("%s: compatible match\n", np->full_name);
 331                         return auxdata;
 332                 }
 333         }
 334
 335         return NULL;
 336 }
 337
 338 /**
 339  * of_platform_bus_create() - Create a device for a node and its children.
 340  * @bus: device node of the bus to instantiate
 341  * @matches: match table for bus nodes
 342  * @lookup: auxdata table for matching id and platform_data with device nodes
 343  * @parent: parent for new device, or NULL for top level.
 344  * @strict: require compatible property
 345  *
 346  * Creates a platform_device for the provided device_node, and optionally
 347  * recursively create devices for all the child nodes.
 348  */
 349 static int of_platform_bus_create(struct device_node *bus,
 350                                   const struct of_device_id *matches,
 351                                   const struct of_dev_auxdata *lookup,
 352                                   struct device *parent, bool strict)
 353 {
 354         const struct of_dev_auxdata *auxdata;
 355         struct device_node *child;
 356         struct platform_device *dev;
 357         const char *bus_id = NULL;
 358         void *platform_data = NULL;
 359         int rc = 0;
 360
 361         /* Make sure it has a compatible property */
 362         if (strict && (!of_get_property(bus, "compatible", NULL))) {
 363                 pr_debug("%s() - skipping %s, no compatible prop\n",
 364                          __func__, bus->full_name);
 365                 return 0;
 366         }
 367
 368         if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
 369                 pr_debug("%s() - skipping %s, already populated\n",
 370                         __func__, bus->full_name);
 371                 return 0;
 372         }
 373
 374         auxdata = of_dev_lookup(lookup, bus);
 375         if (auxdata) {
 376                 bus_id = auxdata->name;
 377                 platform_data = auxdata->platform_data;
 378         }
 379
 380         if (of_device_is_compatible(bus, "arm,primecell")) {
 381                 /*
 382                  * Don't return an error here to keep compatibility with older
 383                  * device tree files.
 384                  */
 385                 of_amba_device_create(bus, bus_id, platform_data, parent);
 386                 return 0;
 387         }
 388
 389         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 390         if (!dev || !of_match_node(matches, bus))
 391                 return 0;
 392
 393         for_each_child_of_node(bus, child) {
 394                 pr_debug("   create child: %s\n", child->full_name);
 395                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 396                 if (rc) {
 397                         of_node_put(child);
 398                         break;
 399                 }
 400         }
 401         of_node_set_flag(bus, OF_POPULATED_BUS);
 402         return rc;
 403 }
 404
 405 /**
 406  * of_platform_bus_probe() - Probe the device-tree for platform buses
 407  * @root: parent of the first level to probe or NULL for the root of the tree
 408  * @matches: match table for bus nodes
 409  * @parent: parent to hook devices from, NULL for toplevel
 410  *
 411  * Note that children of the provided root are not instantiated as devices
 412  * unless the specified root itself matches the bus list and is not NULL.
 413  */
 414 int of_platform_bus_probe(struct device_node *root,
 415                           const struct of_device_id *matches,
 416                           struct device *parent)
 417 {
 418         struct device_node *child;
 419         int rc = 0;
 420
 421         root = root ? of_node_get(root) : of_find_node_by_path("/");
 422         if (!root)
 423                 return -EINVAL;
 424
 425         pr_debug("%s()\n", __func__);
 426         pr_debug(" starting at: %s\n", root->full_name);
 427
 428         /* Do a self check of bus type, if there's a match, create children */
 429         if (of_match_node(matches, root)) {
 430                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
 431         } else for_each_child_of_node(root, child) {
 432                 if (!of_match_node(matches, child))
 433                         continue;
 434                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
 435                 if (rc) {
 436                         of_node_put(child);
 437                         break;
 438                 }
 439         }
 440
 441         of_node_put(root);
 442         return rc;
 443 }
 444 EXPORT_SYMBOL(of_platform_bus_probe);
 445
 446 /**
 447  * of_platform_populate() - Populate platform_devices from device tree data
 448  * @root: parent of the first level to probe or NULL for the root of the tree
 449  * @matches: match table, NULL to use the default
 450  * @lookup: auxdata table for matching id and platform_data with device nodes
 451  * @parent: parent to hook devices from, NULL for toplevel
 452  *
 453  * Similar to of_platform_bus_probe(), this function walks the device tree
 454  * and creates devices from nodes.  It differs in that it follows the modern
 455  * convention of requiring all device nodes to have a 'compatible' property,
 456  * and it is suitable for creating devices which are children of the root
 457  * node (of_platform_bus_probe will only create children of the root which
 458  * are selected by the @matches argument).
 459  *
 460  * New board support should be using this function instead of
 461  * of_platform_bus_probe().
 462  *
 463  * Returns 0 on success, < 0 on failure.
 464  */
 465 int of_platform_populate(struct device_node *root,
 466                         const struct of_device_id *matches,
 467                         const struct of_dev_auxdata *lookup,
 468                         struct device *parent)
 469 {
 470         struct device_node *child;
 471         int rc = 0;
 472
 473         root = root ? of_node_get(root) : of_find_node_by_path("/");
 474         if (!root)
 475                 return -EINVAL;
 476
 477         pr_debug("%s()\n", __func__);
 478         pr_debug(" starting at: %s\n", root->full_name);
 479
 480         for_each_child_of_node(root, child) {
 481                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
 482                 if (rc) {
 483                         of_node_put(child);
 484                         break;
 485                 }
 486         }
 487         of_node_set_flag(root, OF_POPULATED_BUS);
 488
 489         of_node_put(root);
 490         return rc;
 491 }
 492 EXPORT_SYMBOL_GPL(of_platform_populate);
 493
 494 int of_platform_default_populate(struct device_node *root,
 495                                  const struct of_dev_auxdata *lookup,
 496                                  struct device *parent)
 497 {
 498         return of_platform_populate(root, of_default_bus_match_table, lookup,
 499                                     parent);
 500 }
 501 EXPORT_SYMBOL_GPL(of_platform_default_populate);
 502
 503 #ifndef CONFIG_PPC
 504 static int __init of_platform_default_populate_init(void)
 505 {
 506         struct device_node *node;
 507
 508         if (!of_have_populated_dt())
 509                 return -ENODEV;
 510
 511         /*
 512          * Handle ramoops explicitly, since it is inside /reserved-memory,
 513          * which lacks a "compatible" property.
 514          */
 515         node = of_find_node_by_path("/reserved-memory");
 516         if (node) {
 517                 node = of_find_compatible_node(node, NULL, "ramoops");
 518                 if (node)
 519                         of_platform_device_create(node, NULL, NULL);
 520         }
 521
 522         /* Populate everything else. */
 523         of_platform_default_populate(NULL, NULL, NULL);
 524
 525         return 0;
 526 }
 527 arch_initcall_sync(of_platform_default_populate_init);
 528 #endif
 529
 530 static int of_platform_device_destroy(struct device *dev, void *data)
 531 {
 532         /* Do not touch devices not populated from the device tree */
 533         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
 534                 return 0;
 535
 536         /* Recurse for any nodes that were treated as busses */
 537         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
 538                 device_for_each_child(dev, NULL, of_platform_device_destroy);
 539
 540         if (dev->bus == &platform_bus_type)
 541                 platform_device_unregister(to_platform_device(dev));
 542 #ifdef CONFIG_ARM_AMBA
 543         else if (dev->bus == &amba_bustype)
 544                 amba_device_unregister(to_amba_device(dev));
 545 #endif
 546
 547         of_dma_deconfigure(dev);
 548         of_node_clear_flag(dev->of_node, OF_POPULATED);
 549         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 550         return 0;
 551 }
 552
 553 /**
 554  * of_platform_depopulate() - Remove devices populated from device tree
 555  * @parent: device which children will be removed
 556  *
 557  * Complementary to of_platform_populate(), this function removes children
 558  * of the given device (and, recurrently, their children) that have been
 559  * created from their respective device tree nodes (and only those,
 560  * leaving others - eg. manually created - unharmed).
 561  *
 562  * Returns 0 when all children devices have been removed or
 563  * -EBUSY when some children remained.
 564  */
 565 void of_platform_depopulate(struct device *parent)
 566 {
 567         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
 568                 device_for_each_child(parent, NULL, of_platform_device_destroy);
 569                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
 570         }
 571 }
 572 EXPORT_SYMBOL_GPL(of_platform_depopulate);
 573
 574 #ifdef CONFIG_OF_DYNAMIC
 575 static int of_platform_notify(struct notifier_block *nb,
 576                                 unsigned long action, void *arg)
 577 {
 578         struct of_reconfig_data *rd = arg;
 579         struct platform_device *pdev_parent, *pdev;
 580         bool children_left;
 581
 582         switch (of_reconfig_get_state_change(action, rd)) {
 583         case OF_RECONFIG_CHANGE_ADD:
 584                 /* verify that the parent is a bus */
 585                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
 586                         return NOTIFY_OK;       /* not for us */
 587
 588                 /* already populated? (driver using of_populate manually) */
 589                 if (of_node_check_flag(rd->dn, OF_POPULATED))
 590                         return NOTIFY_OK;
 591
 592                 /* pdev_parent may be NULL when no bus platform device */
 593                 pdev_parent = of_find_device_by_node(rd->dn->parent);
 594                 pdev = of_platform_device_create(rd->dn, NULL,
 595                                 pdev_parent ? &pdev_parent->dev : NULL);
 596                 of_dev_put(pdev_parent);
 597
 598                 if (pdev == NULL) {
 599                         pr_err("%s: failed to create for '%s'\n",
 600                                         __func__, rd->dn->full_name);
 601                         /* of_platform_device_create tosses the error code */
 602                         return notifier_from_errno(-EINVAL);
 603                 }
 604                 break;
 605
 606         case OF_RECONFIG_CHANGE_REMOVE:
 607
 608                 /* already depopulated? */
 609                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
 610                         return NOTIFY_OK;
 611
 612                 /* find our device by node */
 613                 pdev = of_find_device_by_node(rd->dn);
 614                 if (pdev == NULL)
 615                         return NOTIFY_OK;       /* no? not meant for us */
 616
 617                 /* unregister takes one ref away */
 618                 of_platform_device_destroy(&pdev->dev, &children_left);
 619
 620                 /* and put the reference of the find */
 621                 of_dev_put(pdev);
 622                 break;
 623         }
 624
 625         return NOTIFY_OK;
 626 }
 627
 628 static struct notifier_block platform_of_notifier = {
 629         .notifier_call = of_platform_notify,
 630 };
 631
 632 void of_platform_register_reconfig_notifier(void)
 633 {
 634         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
 635 }
 636 #endif /* CONFIG_OF_DYNAMIC */
 637
 638 #endif /* CONFIG_OF_ADDRESS */