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;
 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 /**
 153  * of_dma_configure - Setup DMA configuration
 154  * @dev:        Device to apply DMA configuration
 155  *
 156  * Try to get devices's DMA configuration from DT and update it
 157  * accordingly.
 158  *
 159  * In case if platform code need to use own special DMA configuration,it
 160  * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
 161  * to fix up DMA configuration.
 162  */
 163 static void of_dma_configure(struct platform_device *pdev)
 164 {
 165         u64 dma_addr, paddr, size;
 166         int ret;
 167         struct device *dev = &pdev->dev;
 168
 169         /*
 170          * Set default dma-mask to 32 bit. Drivers are expected to setup
 171          * the correct supported dma_mask.
 172          */
 173         dev->coherent_dma_mask = DMA_BIT_MASK(32);
 174
 175         /*
 176          * Set it to coherent_dma_mask by default if the architecture
 177          * code has not set it.
 178          */
 179         if (!dev->dma_mask)
 180                 dev->dma_mask = &dev->coherent_dma_mask;
 181
 182         /*
 183          * if dma-coherent property exist, call arch hook to setup
 184          * dma coherent operations.
 185          */
 186         if (of_dma_is_coherent(dev->of_node)) {
 187                 set_arch_dma_coherent_ops(dev);
 188                 dev_dbg(dev, "device is dma coherent\n");
 189         }
 190
 191         /*
 192          * if dma-ranges property doesn't exist - just return else
 193          * setup the dma offset
 194          */
 195         ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
 196         if (ret < 0) {
 197                 dev_dbg(dev, "no dma range information to setup\n");
 198                 return;
 199         }
 200
 201         /* DMA ranges found. Calculate and set dma_pfn_offset */
 202         dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr);
 203         dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);
 204 }
 205
 206 /**
 207  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 208  * @np: pointer to node to create device for
 209  * @bus_id: name to assign device
 210  * @platform_data: pointer to populate platform_data pointer with
 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 static struct platform_device *of_platform_device_create_pdata(
 217                                         struct device_node *np,
 218                                         const char *bus_id,
 219                                         void *platform_data,
 220                                         struct device *parent)
 221 {
 222         struct platform_device *dev;
 223
 224         if (!of_device_is_available(np) ||
 225             of_node_test_and_set_flag(np, OF_POPULATED))
 226                 return NULL;
 227
 228         dev = of_device_alloc(np, bus_id, parent);
 229         if (!dev)
 230                 goto err_clear_flag;
 231
 232         of_dma_configure(dev);
 233         dev->dev.bus = &platform_bus_type;
 234         dev->dev.platform_data = platform_data;
 235
 236         /* We do not fill the DMA ops for platform devices by default.
 237          * This is currently the responsibility of the platform code
 238          * to do such, possibly using a device notifier
 239          */
 240
 241         if (of_device_add(dev) != 0) {
 242                 platform_device_put(dev);
 243                 goto err_clear_flag;
 244         }
 245
 246         return dev;
 247
 248 err_clear_flag:
 249         of_node_clear_flag(np, OF_POPULATED);
 250         return NULL;
 251 }
 252
 253 /**
 254  * of_platform_device_create - Alloc, initialize and register an of_device
 255  * @np: pointer to node to create device for
 256  * @bus_id: name to assign device
 257  * @parent: Linux device model parent device.
 258  *
 259  * Returns pointer to created platform device, or NULL if a device was not
 260  * registered.  Unavailable devices will not get registered.
 261  */
 262 struct platform_device *of_platform_device_create(struct device_node *np,
 263                                             const char *bus_id,
 264                                             struct device *parent)
 265 {
 266         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 267 }
 268 EXPORT_SYMBOL(of_platform_device_create);
 269
 270 #ifdef CONFIG_ARM_AMBA
 271 static struct amba_device *of_amba_device_create(struct device_node *node,
 272                                                  const char *bus_id,
 273                                                  void *platform_data,
 274                                                  struct device *parent)
 275 {
 276         struct amba_device *dev;
 277         const void *prop;
 278         int i, ret;
 279
 280         pr_debug("Creating amba device %s\n", node->full_name);
 281
 282         if (!of_device_is_available(node) ||
 283             of_node_test_and_set_flag(node, OF_POPULATED))
 284                 return NULL;
 285
 286         dev = amba_device_alloc(NULL, 0, 0);
 287         if (!dev) {
 288                 pr_err("%s(): amba_device_alloc() failed for %s\n",
 289                        __func__, node->full_name);
 290                 goto err_clear_flag;
 291         }
 292
 293         /* setup generic device info */
 294         dev->dev.coherent_dma_mask = ~0;
 295         dev->dev.of_node = of_node_get(node);
 296         dev->dev.parent = parent;
 297         dev->dev.platform_data = platform_data;
 298         if (bus_id)
 299                 dev_set_name(&dev->dev, "%s", bus_id);
 300         else
 301                 of_device_make_bus_id(&dev->dev);
 302
 303         /* Allow the HW Peripheral ID to be overridden */
 304         prop = of_get_property(node, "arm,primecell-periphid", NULL);
 305         if (prop)
 306                 dev->periphid = of_read_ulong(prop, 1);
 307
 308         /* Decode the IRQs and address ranges */
 309         for (i = 0; i < AMBA_NR_IRQS; i++)
 310                 dev->irq[i] = irq_of_parse_and_map(node, i);
 311
 312         ret = of_address_to_resource(node, 0, &dev->res);
 313         if (ret) {
 314                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
 315                        __func__, ret, node->full_name);
 316                 goto err_free;
 317         }
 318
 319         ret = amba_device_add(dev, &iomem_resource);
 320         if (ret) {
 321                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
 322                        __func__, ret, node->full_name);
 323                 goto err_free;
 324         }
 325
 326         return dev;
 327
 328 err_free:
 329         amba_device_put(dev);
 330 err_clear_flag:
 331         of_node_clear_flag(node, OF_POPULATED);
 332         return NULL;
 333 }
 334 #else /* CONFIG_ARM_AMBA */
 335 static struct amba_device *of_amba_device_create(struct device_node *node,
 336                                                  const char *bus_id,
 337                                                  void *platform_data,
 338                                                  struct device *parent)
 339 {
 340         return NULL;
 341 }
 342 #endif /* CONFIG_ARM_AMBA */
 343
 344 /**
 345  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 346  */
 347 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 348                                  struct device_node *np)
 349 {
 350         struct resource res;
 351
 352         if (!lookup)
 353                 return NULL;
 354
 355         for(; lookup->compatible != NULL; lookup++) {
 356                 if (!of_device_is_compatible(np, lookup->compatible))
 357                         continue;
 358                 if (!of_address_to_resource(np, 0, &res))
 359                         if (res.start != lookup->phys_addr)
 360                                 continue;
 361                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
 362                 return lookup;
 363         }
 364
 365         return NULL;
 366 }
 367
 368 /**
 369  * of_platform_bus_create() - Create a device for a node and its children.
 370  * @bus: device node of the bus to instantiate
 371  * @matches: match table for bus nodes
 372  * @lookup: auxdata table for matching id and platform_data with device nodes
 373  * @parent: parent for new device, or NULL for top level.
 374  * @strict: require compatible property
 375  *
 376  * Creates a platform_device for the provided device_node, and optionally
 377  * recursively create devices for all the child nodes.
 378  */
 379 static int of_platform_bus_create(struct device_node *bus,
 380                                   const struct of_device_id *matches,
 381                                   const struct of_dev_auxdata *lookup,
 382                                   struct device *parent, bool strict)
 383 {
 384         const struct of_dev_auxdata *auxdata;
 385         struct device_node *child;
 386         struct platform_device *dev;
 387         const char *bus_id = NULL;
 388         void *platform_data = NULL;
 389         int rc = 0;
 390
 391         /* Make sure it has a compatible property */
 392         if (strict && (!of_get_property(bus, "compatible", NULL))) {
 393                 pr_debug("%s() - skipping %s, no compatible prop\n",
 394                          __func__, bus->full_name);
 395                 return 0;
 396         }
 397
 398         auxdata = of_dev_lookup(lookup, bus);
 399         if (auxdata) {
 400                 bus_id = auxdata->name;
 401                 platform_data = auxdata->platform_data;
 402         }
 403
 404         if (of_device_is_compatible(bus, "arm,primecell")) {
 405                 /*
 406                  * Don't return an error here to keep compatibility with older
 407                  * device tree files.
 408                  */
 409                 of_amba_device_create(bus, bus_id, platform_data, parent);
 410                 return 0;
 411         }
 412
 413         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 414         if (!dev || !of_match_node(matches, bus))
 415                 return 0;
 416
 417         for_each_child_of_node(bus, child) {
 418                 pr_debug("   create child: %s\n", child->full_name);
 419                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 420                 if (rc) {
 421                         of_node_put(child);
 422                         break;
 423                 }
 424         }
 425         of_node_set_flag(bus, OF_POPULATED_BUS);
 426         return rc;
 427 }
 428
 429 /**
 430  * of_platform_bus_probe() - Probe the device-tree for platform buses
 431  * @root: parent of the first level to probe or NULL for the root of the tree
 432  * @matches: match table for bus nodes
 433  * @parent: parent to hook devices from, NULL for toplevel
 434  *
 435  * Note that children of the provided root are not instantiated as devices
 436  * unless the specified root itself matches the bus list and is not NULL.
 437  */
 438 int of_platform_bus_probe(struct device_node *root,
 439                           const struct of_device_id *matches,
 440                           struct device *parent)
 441 {
 442         struct device_node *child;
 443         int rc = 0;
 444
 445         root = root ? of_node_get(root) : of_find_node_by_path("/");
 446         if (!root)
 447                 return -EINVAL;
 448
 449         pr_debug("of_platform_bus_probe()\n");
 450         pr_debug(" starting at: %s\n", root->full_name);
 451
 452         /* Do a self check of bus type, if there's a match, create children */
 453         if (of_match_node(matches, root)) {
 454                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
 455         } else for_each_child_of_node(root, child) {
 456                 if (!of_match_node(matches, child))
 457                         continue;
 458                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
 459                 if (rc)
 460                         break;
 461         }
 462
 463         of_node_put(root);
 464         return rc;
 465 }
 466 EXPORT_SYMBOL(of_platform_bus_probe);
 467
 468 /**
 469  * of_platform_populate() - Populate platform_devices from device tree data
 470  * @root: parent of the first level to probe or NULL for the root of the tree
 471  * @matches: match table, NULL to use the default
 472  * @lookup: auxdata table for matching id and platform_data with device nodes
 473  * @parent: parent to hook devices from, NULL for toplevel
 474  *
 475  * Similar to of_platform_bus_probe(), this function walks the device tree
 476  * and creates devices from nodes.  It differs in that it follows the modern
 477  * convention of requiring all device nodes to have a 'compatible' property,
 478  * and it is suitable for creating devices which are children of the root
 479  * node (of_platform_bus_probe will only create children of the root which
 480  * are selected by the @matches argument).
 481  *
 482  * New board support should be using this function instead of
 483  * of_platform_bus_probe().
 484  *
 485  * Returns 0 on success, < 0 on failure.
 486  */
 487 int of_platform_populate(struct device_node *root,
 488                         const struct of_device_id *matches,
 489                         const struct of_dev_auxdata *lookup,
 490                         struct device *parent)
 491 {
 492         struct device_node *child;
 493         int rc = 0;
 494
 495         root = root ? of_node_get(root) : of_find_node_by_path("/");
 496         if (!root)
 497                 return -EINVAL;
 498
 499         for_each_child_of_node(root, child) {
 500                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
 501                 if (rc)
 502                         break;
 503         }
 504
 505         of_node_put(root);
 506         return rc;
 507 }
 508 EXPORT_SYMBOL_GPL(of_platform_populate);
 509
 510 static int of_platform_device_destroy(struct device *dev, void *data)
 511 {
 512         /* Do not touch devices not populated from the device tree */
 513         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
 514                 return 0;
 515
 516         /* Recurse for any nodes that were treated as busses */
 517         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
 518                 device_for_each_child(dev, NULL, of_platform_device_destroy);
 519
 520         if (dev->bus == &platform_bus_type)
 521                 platform_device_unregister(to_platform_device(dev));
 522 #ifdef CONFIG_ARM_AMBA
 523         else if (dev->bus == &amba_bustype)
 524                 amba_device_unregister(to_amba_device(dev));
 525 #endif
 526
 527         of_node_clear_flag(dev->of_node, OF_POPULATED);
 528         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 529         return 0;
 530 }
 531
 532 /**
 533  * of_platform_depopulate() - Remove devices populated from device tree
 534  * @parent: device which children will be removed
 535  *
 536  * Complementary to of_platform_populate(), this function removes children
 537  * of the given device (and, recurrently, their children) that have been
 538  * created from their respective device tree nodes (and only those,
 539  * leaving others - eg. manually created - unharmed).
 540  *
 541  * Returns 0 when all children devices have been removed or
 542  * -EBUSY when some children remained.
 543  */
 544 void of_platform_depopulate(struct device *parent)
 545 {
 546         device_for_each_child(parent, NULL, of_platform_device_destroy);
 547 }
 548 EXPORT_SYMBOL_GPL(of_platform_depopulate);
 549
 550 #endif /* CONFIG_OF_ADDRESS */