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 #if defined(CONFIG_PPC_DCR)
  55 #include <asm/dcr.h>
  56 #endif
  57
  58 #ifdef CONFIG_OF_ADDRESS
  59 /*
  60  * The following routines scan a subtree and registers a device for
  61  * each applicable node.
  62  *
  63  * Note: sparc doesn't use these routines because it has a different
  64  * mechanism for creating devices from device tree nodes.
  65  */
  66
  67 /**
  68  * of_device_make_bus_id - Use the device node data to assign a unique name
  69  * @dev: pointer to device structure that is linked to a device tree node
  70  *
  71  * This routine will first try using either the dcr-reg or the reg property
  72  * value to derive a unique name.  As a last resort it will use the node
  73  * name followed by a unique number.
  74  */
  75 void of_device_make_bus_id(struct device *dev)
  76 {
  77         static atomic_t bus_no_reg_magic;
  78         struct device_node *node = dev->of_node;
  79         const __be32 *reg;
  80         u64 addr;
  81         const __be32 *addrp;
  82         int magic;
  83
  84 #ifdef CONFIG_PPC_DCR
  85         /*
  86          * If it's a DCR based device, use 'd' for native DCRs
  87          * and 'D' for MMIO DCRs.
  88          */
  89         reg = of_get_property(node, "dcr-reg", NULL);
  90         if (reg) {
  91 #ifdef CONFIG_PPC_DCR_NATIVE
  92                 dev_set_name(dev, "d%x.%s", *reg, node->name);
  93 #else /* CONFIG_PPC_DCR_NATIVE */
  94                 u64 addr = of_translate_dcr_address(node, *reg, NULL);
  95                 if (addr != OF_BAD_ADDR) {
  96                         dev_set_name(dev, "D%llx.%s",
  97                                      (unsigned long long)addr, node->name);
  98                         return;
  99                 }
 100 #endif /* !CONFIG_PPC_DCR_NATIVE */
 101         }
 102 #endif /* CONFIG_PPC_DCR */
 103
 104         /*
 105          * For MMIO, get the physical address
 106          */
 107         reg = of_get_property(node, "reg", NULL);
 108         if (reg) {
 109                 if (of_can_translate_address(node)) {
 110                         addr = of_translate_address(node, reg);
 111                 } else {
 112                         addrp = of_get_address(node, 0, NULL, NULL);
 113                         if (addrp)
 114                                 addr = of_read_number(addrp, 1);
 115                         else
 116                                 addr = OF_BAD_ADDR;
 117                 }
 118                 if (addr != OF_BAD_ADDR) {
 119                         dev_set_name(dev, "%llx.%s",
 120                                      (unsigned long long)addr, node->name);
 121                         return;
 122                 }
 123         }
 124
 125         /*
 126          * No BusID, use the node name and add a globally incremented
 127          * counter (and pray...)
 128          */
 129         magic = atomic_add_return(1, &bus_no_reg_magic);
 130         dev_set_name(dev, "%s.%d", node->name, magic - 1);
 131 }
 132
 133 /**
 134  * of_device_alloc - Allocate and initialize an of_device
 135  * @np: device node to assign to device
 136  * @bus_id: Name to assign to the device.  May be null to use default name.
 137  * @parent: Parent device.
 138  */
 139 struct platform_device *of_device_alloc(struct device_node *np,
 140                                   const char *bus_id,
 141                                   struct device *parent)
 142 {
 143         struct platform_device *dev;
 144         int rc, i, num_reg = 0, num_irq;
 145         struct resource *res, temp_res;
 146
 147         dev = platform_device_alloc("", -1);
 148         if (!dev)
 149                 return NULL;
 150
 151         /* count the io and irq resources */
 152         if (of_can_translate_address(np))
 153                 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 154                         num_reg++;
 155         num_irq = of_irq_count(np);
 156
 157         /* Populate the resource table */
 158         if (num_irq || num_reg) {
 159                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 160                 if (!res) {
 161                         platform_device_put(dev);
 162                         return NULL;
 163                 }
 164
 165                 dev->num_resources = num_reg + num_irq;
 166                 dev->resource = res;
 167                 for (i = 0; i < num_reg; i++, res++) {
 168                         rc = of_address_to_resource(np, i, res);
 169                         WARN_ON(rc);
 170                 }
 171                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
 172                         pr_debug("not all legacy IRQ resources mapped for %s\n",
 173                                  np->name);
 174         }
 175
 176         dev->dev.of_node = of_node_get(np);
 177 #if defined(CONFIG_MICROBLAZE)
 178         dev->dev.dma_mask = &dev->archdata.dma_mask;
 179 #endif
 180         dev->dev.parent = parent;
 181
 182         if (bus_id)
 183                 dev_set_name(&dev->dev, "%s", bus_id);
 184         else
 185                 of_device_make_bus_id(&dev->dev);
 186
 187         return dev;
 188 }
 189 EXPORT_SYMBOL(of_device_alloc);
 190
 191 /**
 192  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 193  * @np: pointer to node to create device for
 194  * @bus_id: name to assign device
 195  * @platform_data: pointer to populate platform_data pointer with
 196  * @parent: Linux device model parent device.
 197  *
 198  * Returns pointer to created platform device, or NULL if a device was not
 199  * registered.  Unavailable devices will not get registered.
 200  */
 201 static struct platform_device *of_platform_device_create_pdata(
 202                                         struct device_node *np,
 203                                         const char *bus_id,
 204                                         void *platform_data,
 205                                         struct device *parent)
 206 {
 207         struct platform_device *dev;
 208
 209         if (!of_device_is_available(np))
 210                 return NULL;
 211
 212         dev = of_device_alloc(np, bus_id, parent);
 213         if (!dev)
 214                 return NULL;
 215
 216 #if defined(CONFIG_MICROBLAZE)
 217         dev->archdata.dma_mask = 0xffffffffUL;
 218 #endif
 219         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 220         if (!dev->dev.dma_mask)
 221                 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
 222         dev->dev.bus = &platform_bus_type;
 223         dev->dev.platform_data = platform_data;
 224
 225         /* We do not fill the DMA ops for platform devices by default.
 226          * This is currently the responsibility of the platform code
 227          * to do such, possibly using a device notifier
 228          */
 229
 230         if (of_device_add(dev) != 0) {
 231                 platform_device_put(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         /* Allow the HW Peripheral ID to be overridden */
 288         prop = of_get_property(node, "arm,primecell-periphid", NULL);
 289         if (prop)
 290                 dev->periphid = of_read_ulong(prop, 1);
 291
 292         /* Decode the IRQs and address ranges */
 293         for (i = 0; i < AMBA_NR_IRQS; i++)
 294                 dev->irq[i] = irq_of_parse_and_map(node, i);
 295
 296         ret = of_address_to_resource(node, 0, &dev->res);
 297         if (ret) {
 298                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
 299                        __func__, ret, node->full_name);
 300                 goto err_free;
 301         }
 302
 303         ret = amba_device_add(dev, &iomem_resource);
 304         if (ret) {
 305                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
 306                        __func__, ret, node->full_name);
 307                 goto err_free;
 308         }
 309
 310         return dev;
 311
 312 err_free:
 313         amba_device_put(dev);
 314         return NULL;
 315 }
 316 #else /* CONFIG_ARM_AMBA */
 317 static struct amba_device *of_amba_device_create(struct device_node *node,
 318                                                  const char *bus_id,
 319                                                  void *platform_data,
 320                                                  struct device *parent)
 321 {
 322         return NULL;
 323 }
 324 #endif /* CONFIG_ARM_AMBA */
 325
 326 /**
 327  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 328  */
 329 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 330                                  struct device_node *np)
 331 {
 332         struct resource res;
 333
 334         if (!lookup)
 335                 return NULL;
 336
 337         for(; lookup->compatible != NULL; lookup++) {
 338                 if (!of_device_is_compatible(np, lookup->compatible))
 339                         continue;
 340                 if (!of_address_to_resource(np, 0, &res))
 341                         if (res.start != lookup->phys_addr)
 342                                 continue;
 343                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
 344                 return lookup;
 345         }
 346
 347         return NULL;
 348 }
 349
 350 /**
 351  * of_platform_bus_create() - Create a device for a node and its children.
 352  * @bus: device node of the bus to instantiate
 353  * @matches: match table for bus nodes
 354  * @lookup: auxdata table for matching id and platform_data with device nodes
 355  * @parent: parent for new device, or NULL for top level.
 356  * @strict: require compatible property
 357  *
 358  * Creates a platform_device for the provided device_node, and optionally
 359  * recursively create devices for all the child nodes.
 360  */
 361 static int of_platform_bus_create(struct device_node *bus,
 362                                   const struct of_device_id *matches,
 363                                   const struct of_dev_auxdata *lookup,
 364                                   struct device *parent, bool strict)
 365 {
 366         const struct of_dev_auxdata *auxdata;
 367         struct device_node *child;
 368         struct platform_device *dev;
 369         const char *bus_id = NULL;
 370         void *platform_data = NULL;
 371         int rc = 0;
 372
 373         /* Make sure it has a compatible property */
 374         if (strict && (!of_get_property(bus, "compatible", NULL))) {
 375                 pr_debug("%s() - skipping %s, no compatible prop\n",
 376                          __func__, bus->full_name);
 377                 return 0;
 378         }
 379
 380         auxdata = of_dev_lookup(lookup, bus);
 381         if (auxdata) {
 382                 bus_id = auxdata->name;
 383                 platform_data = auxdata->platform_data;
 384         }
 385
 386         if (of_device_is_compatible(bus, "arm,primecell")) {
 387                 /*
 388                  * Don't return an error here to keep compatibility with older
 389                  * device tree files.
 390                  */
 391                 of_amba_device_create(bus, bus_id, platform_data, parent);
 392                 return 0;
 393         }
 394
 395         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 396         if (!dev || !of_match_node(matches, bus))
 397                 return 0;
 398
 399         for_each_child_of_node(bus, child) {
 400                 pr_debug("   create child: %s\n", child->full_name);
 401                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 402                 if (rc) {
 403                         of_node_put(child);
 404                         break;
 405                 }
 406         }
 407         return rc;
 408 }
 409
 410 /**
 411  * of_platform_bus_probe() - Probe the device-tree for platform buses
 412  * @root: parent of the first level to probe or NULL for the root of the tree
 413  * @matches: match table for bus nodes
 414  * @parent: parent to hook devices from, NULL for toplevel
 415  *
 416  * Note that children of the provided root are not instantiated as devices
 417  * unless the specified root itself matches the bus list and is not NULL.
 418  */
 419 int of_platform_bus_probe(struct device_node *root,
 420                           const struct of_device_id *matches,
 421                           struct device *parent)
 422 {
 423         struct device_node *child;
 424         int rc = 0;
 425
 426         root = root ? of_node_get(root) : of_find_node_by_path("/");
 427         if (!root)
 428                 return -EINVAL;
 429
 430         pr_debug("of_platform_bus_probe()\n");
 431         pr_debug(" starting at: %s\n", root->full_name);
 432
 433         /* Do a self check of bus type, if there's a match, create children */
 434         if (of_match_node(matches, root)) {
 435                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
 436         } else for_each_child_of_node(root, child) {
 437                 if (!of_match_node(matches, child))
 438                         continue;
 439                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
 440                 if (rc)
 441                         break;
 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         for_each_child_of_node(root, child) {
 481                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
 482                 if (rc)
 483                         break;
 484         }
 485
 486         of_node_put(root);
 487         return rc;
 488 }
 489 EXPORT_SYMBOL_GPL(of_platform_populate);
 490 #endif /* CONFIG_OF_ADDRESS */