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