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/of_reserved_mem.h>
  25 #include <linux/platform_device.h>
  26
  27 const struct of_device_id of_default_bus_match_table[] = {
  28         { .compatible = "simple-bus", },
  29 #ifdef CONFIG_ARM_AMBA
  30         { .compatible = "arm,amba-bus", },
  31 #endif /* CONFIG_ARM_AMBA */
  32         {} /* Empty terminated list */
  33 };
  34
  35 static int of_dev_node_match(struct device *dev, void *data)
  36 {
  37         return dev->of_node == data;
  38 }
  39
  40 /**
  41  * of_find_device_by_node - Find the platform_device associated with a node
  42  * @np: Pointer to device tree node
  43  *
  44  * Returns platform_device pointer, or NULL if not found
  45  */
  46 struct platform_device *of_find_device_by_node(struct device_node *np)
  47 {
  48         struct device *dev;
  49
  50         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  51         return dev ? to_platform_device(dev) : NULL;
  52 }
  53 EXPORT_SYMBOL(of_find_device_by_node);
  54
  55 #if defined(CONFIG_PPC_DCR)
  56 #include <asm/dcr.h>
  57 #endif
  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 either the dcr-reg or the reg property
  73  * value to derive a unique name.  As a last resort it will use the node
  74  * name followed by a unique number.
  75  */
  76 void of_device_make_bus_id(struct device *dev)
  77 {
  78         static atomic_t bus_no_reg_magic;
  79         struct device_node *node = dev->of_node;
  80         const __be32 *reg;
  81         u64 addr;
  82         const __be32 *addrp;
  83         int magic;
  84
  85 #ifdef CONFIG_PPC_DCR
  86         /*
  87          * If it's a DCR based device, use 'd' for native DCRs
  88          * and 'D' for MMIO DCRs.
  89          */
  90         reg = of_get_property(node, "dcr-reg", NULL);
  91         if (reg) {
  92 #ifdef CONFIG_PPC_DCR_NATIVE
  93                 dev_set_name(dev, "d%x.%s", *reg, node->name);
  94 #else /* CONFIG_PPC_DCR_NATIVE */
  95                 u64 addr = of_translate_dcr_address(node, *reg, NULL);
  96                 if (addr != OF_BAD_ADDR) {
  97                         dev_set_name(dev, "D%llx.%s",
  98                                      (unsigned long long)addr, node->name);
  99                         return;
 100                 }
 101 #endif /* !CONFIG_PPC_DCR_NATIVE */
 102         }
 103 #endif /* CONFIG_PPC_DCR */
 104
 105         /*
 106          * For MMIO, get the physical address
 107          */
 108         reg = of_get_property(node, "reg", NULL);
 109         if (reg) {
 110                 if (of_can_translate_address(node)) {
 111                         addr = of_translate_address(node, reg);
 112                 } else {
 113                         addrp = of_get_address(node, 0, NULL, NULL);
 114                         if (addrp)
 115                                 addr = of_read_number(addrp, 1);
 116                         else
 117                                 addr = OF_BAD_ADDR;
 118                 }
 119                 if (addr != OF_BAD_ADDR) {
 120                         dev_set_name(dev, "%llx.%s",
 121                                      (unsigned long long)addr, node->name);
 122                         return;
 123                 }
 124         }
 125
 126         /*
 127          * No BusID, use the node name and add a globally incremented
 128          * counter (and pray...)
 129          */
 130         magic = atomic_add_return(1, &bus_no_reg_magic);
 131         dev_set_name(dev, "%s.%d", node->name, magic - 1);
 132 }
 133
 134 /**
 135  * of_device_alloc - Allocate and initialize an of_device
 136  * @np: device node to assign to device
 137  * @bus_id: Name to assign to the device.  May be null to use default name.
 138  * @parent: Parent device.
 139  */
 140 struct platform_device *of_device_alloc(struct device_node *np,
 141                                   const char *bus_id,
 142                                   struct device *parent)
 143 {
 144         struct platform_device *dev;
 145         int rc, i, num_reg = 0, num_irq;
 146         struct resource *res, temp_res;
 147
 148         dev = platform_device_alloc("", -1);
 149         if (!dev)
 150                 return NULL;
 151
 152         /* count the io and irq resources */
 153         if (of_can_translate_address(np))
 154                 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 155                         num_reg++;
 156         num_irq = of_irq_count(np);
 157
 158         /* Populate the resource table */
 159         if (num_irq || num_reg) {
 160                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 161                 if (!res) {
 162                         platform_device_put(dev);
 163                         return NULL;
 164                 }
 165
 166                 dev->num_resources = num_reg + num_irq;
 167                 dev->resource = res;
 168                 for (i = 0; i < num_reg; i++, res++) {
 169                         rc = of_address_to_resource(np, i, res);
 170                         WARN_ON(rc);
 171                 }
 172                 WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
 173         }
 174
 175         dev->dev.of_node = of_node_get(np);
 176 #if defined(CONFIG_MICROBLAZE)
 177         dev->dev.dma_mask = &dev->archdata.dma_mask;
 178 #endif
 179         dev->dev.parent = parent;
 180
 181         if (bus_id)
 182                 dev_set_name(&dev->dev, "%s", bus_id);
 183         else
 184                 of_device_make_bus_id(&dev->dev);
 185
 186         return dev;
 187 }
 188 EXPORT_SYMBOL(of_device_alloc);
 189
 190 /**
 191  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 192  * @np: pointer to node to create device for
 193  * @bus_id: name to assign device
 194  * @platform_data: pointer to populate platform_data pointer with
 195  * @parent: Linux device model parent device.
 196  *
 197  * Returns pointer to created platform device, or NULL if a device was not
 198  * registered.  Unavailable devices will not get registered.
 199  */
 200 static struct platform_device *of_platform_device_create_pdata(
 201                                         struct device_node *np,
 202                                         const char *bus_id,
 203                                         void *platform_data,
 204                                         struct device *parent)
 205 {
 206         struct platform_device *dev;
 207
 208         if (!of_device_is_available(np))
 209                 return NULL;
 210
 211         dev = of_device_alloc(np, bus_id, parent);
 212         if (!dev)
 213                 return NULL;
 214
 215 #if defined(CONFIG_MICROBLAZE)
 216         dev->archdata.dma_mask = 0xffffffffUL;
 217 #endif
 218         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 219         dev->dev.bus = &platform_bus_type;
 220         dev->dev.platform_data = platform_data;
 221
 222         of_reserved_mem_device_init(&dev->dev);
 223
 224         /* We do not fill the DMA ops for platform devices by default.
 225          * This is currently the responsibility of the platform code
 226          * to do such, possibly using a device notifier
 227          */
 228
 229         if (of_device_add(dev) != 0) {
 230                 platform_device_put(dev);
 231                 of_reserved_mem_device_release(&dev->dev);
 232                 return NULL;
 233         }
 234
 235         return dev;
 236 }
 237
 238 /**
 239  * of_platform_device_create - Alloc, initialize and register an of_device
 240  * @np: pointer to node to create device for
 241  * @bus_id: name to assign device
 242  * @parent: Linux device model parent device.
 243  *
 244  * Returns pointer to created platform device, or NULL if a device was not
 245  * registered.  Unavailable devices will not get registered.
 246  */
 247 struct platform_device *of_platform_device_create(struct device_node *np,
 248                                             const char *bus_id,
 249                                             struct device *parent)
 250 {
 251         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 252 }
 253 EXPORT_SYMBOL(of_platform_device_create);
 254
 255 #ifdef CONFIG_ARM_AMBA
 256 static struct amba_device *of_amba_device_create(struct device_node *node,
 257                                                  const char *bus_id,
 258                                                  void *platform_data,
 259                                                  struct device *parent)
 260 {
 261         struct amba_device *dev;
 262         const void *prop;
 263         int i, ret;
 264
 265         pr_debug("Creating amba device %s\n", node->full_name);
 266
 267         if (!of_device_is_available(node))
 268                 return NULL;
 269
 270         dev = amba_device_alloc(NULL, 0, 0);
 271         if (!dev) {
 272                 pr_err("%s(): amba_device_alloc() failed for %s\n",
 273                        __func__, node->full_name);
 274                 return NULL;
 275         }
 276
 277         /* setup generic device info */
 278         dev->dev.coherent_dma_mask = ~0;
 279         dev->dev.of_node = of_node_get(node);
 280         dev->dev.parent = parent;
 281         dev->dev.platform_data = platform_data;
 282         if (bus_id)
 283                 dev_set_name(&dev->dev, "%s", bus_id);
 284         else
 285                 of_device_make_bus_id(&dev->dev);
 286
 287         /* setup amba-specific device info */
 288         dev->dma_mask = ~0;
 289
 290         /* Allow the HW Peripheral ID to be overridden */
 291         prop = of_get_property(node, "arm,primecell-periphid", NULL);
 292         if (prop)
 293                 dev->periphid = of_read_ulong(prop, 1);
 294
 295         /* Decode the IRQs and address ranges */
 296         for (i = 0; i < AMBA_NR_IRQS; i++)
 297                 dev->irq[i] = irq_of_parse_and_map(node, i);
 298
 299         ret = of_address_to_resource(node, 0, &dev->res);
 300         if (ret) {
 301                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
 302                        __func__, ret, node->full_name);
 303                 goto err_free;
 304         }
 305
 306         ret = amba_device_add(dev, &iomem_resource);
 307         if (ret) {
 308                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
 309                        __func__, ret, node->full_name);
 310                 goto err_free;
 311         }
 312
 313         return dev;
 314
 315 err_free:
 316         amba_device_put(dev);
 317         return NULL;
 318 }
 319 #else /* CONFIG_ARM_AMBA */
 320 static struct amba_device *of_amba_device_create(struct device_node *node,
 321                                                  const char *bus_id,
 322                                                  void *platform_data,
 323                                                  struct device *parent)
 324 {
 325         return NULL;
 326 }
 327 #endif /* CONFIG_ARM_AMBA */
 328
 329 /**
 330  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 331  */
 332 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 333                                  struct device_node *np)
 334 {
 335         struct resource res;
 336
 337         if (!lookup)
 338                 return NULL;
 339
 340         for(; lookup->compatible != NULL; lookup++) {
 341                 if (!of_device_is_compatible(np, lookup->compatible))
 342                         continue;
 343                 if (!of_address_to_resource(np, 0, &res))
 344                         if (res.start != lookup->phys_addr)
 345                                 continue;
 346                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
 347                 return lookup;
 348         }
 349
 350         return NULL;
 351 }
 352
 353 /**
 354  * of_platform_bus_create() - Create a device for a node and its children.
 355  * @bus: device node of the bus to instantiate
 356  * @matches: match table for bus nodes
 357  * @lookup: auxdata table for matching id and platform_data with device nodes
 358  * @parent: parent for new device, or NULL for top level.
 359  * @strict: require compatible property
 360  *
 361  * Creates a platform_device for the provided device_node, and optionally
 362  * recursively create devices for all the child nodes.
 363  */
 364 static int of_platform_bus_create(struct device_node *bus,
 365                                   const struct of_device_id *matches,
 366                                   const struct of_dev_auxdata *lookup,
 367                                   struct device *parent, bool strict)
 368 {
 369         const struct of_dev_auxdata *auxdata;
 370         struct device_node *child;
 371         struct platform_device *dev;
 372         const char *bus_id = NULL;
 373         void *platform_data = NULL;
 374         int rc = 0;
 375
 376         /* Make sure it has a compatible property */
 377         if (strict && (!of_get_property(bus, "compatible", NULL))) {
 378                 pr_debug("%s() - skipping %s, no compatible prop\n",
 379                          __func__, bus->full_name);
 380                 return 0;
 381         }
 382
 383         auxdata = of_dev_lookup(lookup, bus);
 384         if (auxdata) {
 385                 bus_id = auxdata->name;
 386                 platform_data = auxdata->platform_data;
 387         }
 388
 389         if (of_device_is_compatible(bus, "arm,primecell")) {
 390                 /*
 391                  * Don't return an error here to keep compatibility with older
 392                  * device tree files.
 393                  */
 394                 of_amba_device_create(bus, bus_id, platform_data, parent);
 395                 return 0;
 396         }
 397
 398         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 399         if (!dev || !of_match_node(matches, bus))
 400                 return 0;
 401
 402         for_each_child_of_node(bus, child) {
 403                 pr_debug("   create child: %s\n", child->full_name);
 404                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 405                 if (rc) {
 406                         of_node_put(child);
 407                         break;
 408                 }
 409         }
 410         return rc;
 411 }
 412
 413 /**
 414  * of_platform_bus_probe() - Probe the device-tree for platform buses
 415  * @root: parent of the first level to probe or NULL for the root of the tree
 416  * @matches: match table for bus nodes
 417  * @parent: parent to hook devices from, NULL for toplevel
 418  *
 419  * Note that children of the provided root are not instantiated as devices
 420  * unless the specified root itself matches the bus list and is not NULL.
 421  */
 422 int of_platform_bus_probe(struct device_node *root,
 423                           const struct of_device_id *matches,
 424                           struct device *parent)
 425 {
 426         struct device_node *child;
 427         int rc = 0;
 428
 429         root = root ? of_node_get(root) : of_find_node_by_path("/");
 430         if (!root)
 431                 return -EINVAL;
 432
 433         pr_debug("of_platform_bus_probe()\n");
 434         pr_debug(" starting at: %s\n", root->full_name);
 435
 436         /* Do a self check of bus type, if there's a match, create children */
 437         if (of_match_node(matches, root)) {
 438                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
 439         } else for_each_child_of_node(root, child) {
 440                 if (!of_match_node(matches, child))
 441                         continue;
 442                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
 443                 if (rc)
 444                         break;
 445         }
 446
 447         of_node_put(root);
 448         return rc;
 449 }
 450 EXPORT_SYMBOL(of_platform_bus_probe);
 451
 452 /**
 453  * of_platform_populate() - Populate platform_devices from device tree data
 454  * @root: parent of the first level to probe or NULL for the root of the tree
 455  * @matches: match table, NULL to use the default
 456  * @lookup: auxdata table for matching id and platform_data with device nodes
 457  * @parent: parent to hook devices from, NULL for toplevel
 458  *
 459  * Similar to of_platform_bus_probe(), this function walks the device tree
 460  * and creates devices from nodes.  It differs in that it follows the modern
 461  * convention of requiring all device nodes to have a 'compatible' property,
 462  * and it is suitable for creating devices which are children of the root
 463  * node (of_platform_bus_probe will only create children of the root which
 464  * are selected by the @matches argument).
 465  *
 466  * New board support should be using this function instead of
 467  * of_platform_bus_probe().
 468  *
 469  * Returns 0 on success, < 0 on failure.
 470  */
 471 int of_platform_populate(struct device_node *root,
 472                         const struct of_device_id *matches,
 473                         const struct of_dev_auxdata *lookup,
 474                         struct device *parent)
 475 {
 476         struct device_node *child;
 477         int rc = 0;
 478
 479         root = root ? of_node_get(root) : of_find_node_by_path("/");
 480         if (!root)
 481                 return -EINVAL;
 482
 483         for_each_child_of_node(root, child) {
 484                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
 485                 if (rc)
 486                         break;
 487         }
 488
 489         of_node_put(root);
 490         return rc;
 491 }
 492 EXPORT_SYMBOL_GPL(of_platform_populate);
 493 #endif /* CONFIG_OF_ADDRESS */