linux/drivers/of/platform.c
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   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
  26const 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
  34static 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 */
  45struct 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}
  52EXPORT_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 */
  75void 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 u32 *reg;
  80        u64 addr;
  81        int magic;
  82
  83#ifdef CONFIG_PPC_DCR
  84        /*
  85         * If it's a DCR based device, use 'd' for native DCRs
  86         * and 'D' for MMIO DCRs.
  87         */
  88        reg = of_get_property(node, "dcr-reg", NULL);
  89        if (reg) {
  90#ifdef CONFIG_PPC_DCR_NATIVE
  91                dev_set_name(dev, "d%x.%s", *reg, node->name);
  92#else /* CONFIG_PPC_DCR_NATIVE */
  93                u64 addr = of_translate_dcr_address(node, *reg, NULL);
  94                if (addr != OF_BAD_ADDR) {
  95                        dev_set_name(dev, "D%llx.%s",
  96                                     (unsigned long long)addr, node->name);
  97                        return;
  98                }
  99#endif /* !CONFIG_PPC_DCR_NATIVE */
 100        }
 101#endif /* CONFIG_PPC_DCR */
 102
 103        /*
 104         * For MMIO, get the physical address
 105         */
 106        reg = of_get_property(node, "reg", NULL);
 107        if (reg) {
 108                addr = of_translate_address(node, reg);
 109                if (addr != OF_BAD_ADDR) {
 110                        dev_set_name(dev, "%llx.%s",
 111                                     (unsigned long long)addr, node->name);
 112                        return;
 113                }
 114        }
 115
 116        /*
 117         * No BusID, use the node name and add a globally incremented
 118         * counter (and pray...)
 119         */
 120        magic = atomic_add_return(1, &bus_no_reg_magic);
 121        dev_set_name(dev, "%s.%d", node->name, magic - 1);
 122}
 123
 124/**
 125 * of_device_alloc - Allocate and initialize an of_device
 126 * @np: device node to assign to device
 127 * @bus_id: Name to assign to the device.  May be null to use default name.
 128 * @parent: Parent device.
 129 */
 130struct platform_device *of_device_alloc(struct device_node *np,
 131                                  const char *bus_id,
 132                                  struct device *parent)
 133{
 134        struct platform_device *dev;
 135        int rc, i, num_reg = 0, num_irq;
 136        struct resource *res, temp_res;
 137
 138        dev = platform_device_alloc("", -1);
 139        if (!dev)
 140                return NULL;
 141
 142        /* count the io and irq resources */
 143        while (of_address_to_resource(np, num_reg, &temp_res) == 0)
 144                num_reg++;
 145        num_irq = of_irq_count(np);
 146
 147        /* Populate the resource table */
 148        if (num_irq || num_reg) {
 149                res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
 150                if (!res) {
 151                        platform_device_put(dev);
 152                        return NULL;
 153                }
 154
 155                dev->num_resources = num_reg + num_irq;
 156                dev->resource = res;
 157                for (i = 0; i < num_reg; i++, res++) {
 158                        rc = of_address_to_resource(np, i, res);
 159                        WARN_ON(rc);
 160                }
 161                WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
 162        }
 163
 164        dev->dev.of_node = of_node_get(np);
 165#if defined(CONFIG_MICROBLAZE)
 166        dev->dev.dma_mask = &dev->archdata.dma_mask;
 167#endif
 168        dev->dev.parent = parent;
 169
 170        if (bus_id)
 171                dev_set_name(&dev->dev, "%s", bus_id);
 172        else
 173                of_device_make_bus_id(&dev->dev);
 174
 175        return dev;
 176}
 177EXPORT_SYMBOL(of_device_alloc);
 178
 179/**
 180 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 181 * @np: pointer to node to create device for
 182 * @bus_id: name to assign device
 183 * @platform_data: pointer to populate platform_data pointer with
 184 * @parent: Linux device model parent device.
 185 *
 186 * Returns pointer to created platform device, or NULL if a device was not
 187 * registered.  Unavailable devices will not get registered.
 188 */
 189struct platform_device *of_platform_device_create_pdata(
 190                                        struct device_node *np,
 191                                        const char *bus_id,
 192                                        void *platform_data,
 193                                        struct device *parent)
 194{
 195        struct platform_device *dev;
 196
 197        if (!of_device_is_available(np))
 198                return NULL;
 199
 200        dev = of_device_alloc(np, bus_id, parent);
 201        if (!dev)
 202                return NULL;
 203
 204#if defined(CONFIG_MICROBLAZE)
 205        dev->archdata.dma_mask = 0xffffffffUL;
 206#endif
 207        dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 208        dev->dev.bus = &platform_bus_type;
 209        dev->dev.platform_data = platform_data;
 210
 211        /* We do not fill the DMA ops for platform devices by default.
 212         * This is currently the responsibility of the platform code
 213         * to do such, possibly using a device notifier
 214         */
 215
 216        if (of_device_add(dev) != 0) {
 217                platform_device_put(dev);
 218                return NULL;
 219        }
 220
 221        return dev;
 222}
 223
 224/**
 225 * of_platform_device_create - Alloc, initialize and register an of_device
 226 * @np: pointer to node to create device for
 227 * @bus_id: name to assign device
 228 * @parent: Linux device model parent device.
 229 *
 230 * Returns pointer to created platform device, or NULL if a device was not
 231 * registered.  Unavailable devices will not get registered.
 232 */
 233struct platform_device *of_platform_device_create(struct device_node *np,
 234                                            const char *bus_id,
 235                                            struct device *parent)
 236{
 237        return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 238}
 239EXPORT_SYMBOL(of_platform_device_create);
 240
 241#ifdef CONFIG_ARM_AMBA
 242static struct amba_device *of_amba_device_create(struct device_node *node,
 243                                                 const char *bus_id,
 244                                                 void *platform_data,
 245                                                 struct device *parent)
 246{
 247        struct amba_device *dev;
 248        const void *prop;
 249        int i, ret;
 250
 251        pr_debug("Creating amba device %s\n", node->full_name);
 252
 253        if (!of_device_is_available(node))
 254                return NULL;
 255
 256        dev = amba_device_alloc(NULL, 0, 0);
 257        if (!dev)
 258                return NULL;
 259
 260        /* setup generic device info */
 261        dev->dev.coherent_dma_mask = ~0;
 262        dev->dev.of_node = of_node_get(node);
 263        dev->dev.parent = parent;
 264        dev->dev.platform_data = platform_data;
 265        if (bus_id)
 266                dev_set_name(&dev->dev, "%s", bus_id);
 267        else
 268                of_device_make_bus_id(&dev->dev);
 269
 270        /* setup amba-specific device info */
 271        dev->dma_mask = ~0;
 272
 273        /* Allow the HW Peripheral ID to be overridden */
 274        prop = of_get_property(node, "arm,primecell-periphid", NULL);
 275        if (prop)
 276                dev->periphid = of_read_ulong(prop, 1);
 277
 278        /* Decode the IRQs and address ranges */
 279        for (i = 0; i < AMBA_NR_IRQS; i++)
 280                dev->irq[i] = irq_of_parse_and_map(node, i);
 281
 282        ret = of_address_to_resource(node, 0, &dev->res);
 283        if (ret)
 284                goto err_free;
 285
 286        ret = amba_device_add(dev, &iomem_resource);
 287        if (ret)
 288                goto err_free;
 289
 290        return dev;
 291
 292err_free:
 293        amba_device_put(dev);
 294        return NULL;
 295}
 296#else /* CONFIG_ARM_AMBA */
 297static struct amba_device *of_amba_device_create(struct device_node *node,
 298                                                 const char *bus_id,
 299                                                 void *platform_data,
 300                                                 struct device *parent)
 301{
 302        return NULL;
 303}
 304#endif /* CONFIG_ARM_AMBA */
 305
 306/**
 307 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 308 */
 309static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 310                                 struct device_node *np)
 311{
 312        struct resource res;
 313
 314        if (!lookup)
 315                return NULL;
 316
 317        for(; lookup->compatible != NULL; lookup++) {
 318                if (!of_device_is_compatible(np, lookup->compatible))
 319                        continue;
 320                if (!of_address_to_resource(np, 0, &res))
 321                        if (res.start != lookup->phys_addr)
 322                                continue;
 323                pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
 324                return lookup;
 325        }
 326
 327        return NULL;
 328}
 329
 330/**
 331 * of_platform_bus_create() - Create a device for a node and its children.
 332 * @bus: device node of the bus to instantiate
 333 * @matches: match table for bus nodes
 334 * @lookup: auxdata table for matching id and platform_data with device nodes
 335 * @parent: parent for new device, or NULL for top level.
 336 * @strict: require compatible property
 337 *
 338 * Creates a platform_device for the provided device_node, and optionally
 339 * recursively create devices for all the child nodes.
 340 */
 341static int of_platform_bus_create(struct device_node *bus,
 342                                  const struct of_device_id *matches,
 343                                  const struct of_dev_auxdata *lookup,
 344                                  struct device *parent, bool strict)
 345{
 346        const struct of_dev_auxdata *auxdata;
 347        struct device_node *child;
 348        struct platform_device *dev;
 349        const char *bus_id = NULL;
 350        void *platform_data = NULL;
 351        int rc = 0;
 352
 353        /* Make sure it has a compatible property */
 354        if (strict && (!of_get_property(bus, "compatible", NULL))) {
 355                pr_debug("%s() - skipping %s, no compatible prop\n",
 356                         __func__, bus->full_name);
 357                return 0;
 358        }
 359
 360        auxdata = of_dev_lookup(lookup, bus);
 361        if (auxdata) {
 362                bus_id = auxdata->name;
 363                platform_data = auxdata->platform_data;
 364        }
 365
 366        if (of_device_is_compatible(bus, "arm,primecell")) {
 367                of_amba_device_create(bus, bus_id, platform_data, parent);
 368                return 0;
 369        }
 370
 371        dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 372        if (!dev || !of_match_node(matches, bus))
 373                return 0;
 374
 375        for_each_child_of_node(bus, child) {
 376                pr_debug("   create child: %s\n", child->full_name);
 377                rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 378                if (rc) {
 379                        of_node_put(child);
 380                        break;
 381                }
 382        }
 383        return rc;
 384}
 385
 386/**
 387 * of_platform_bus_probe() - Probe the device-tree for platform buses
 388 * @root: parent of the first level to probe or NULL for the root of the tree
 389 * @matches: match table for bus nodes
 390 * @parent: parent to hook devices from, NULL for toplevel
 391 *
 392 * Note that children of the provided root are not instantiated as devices
 393 * unless the specified root itself matches the bus list and is not NULL.
 394 */
 395int of_platform_bus_probe(struct device_node *root,
 396                          const struct of_device_id *matches,
 397                          struct device *parent)
 398{
 399        struct device_node *child;
 400        int rc = 0;
 401
 402        root = root ? of_node_get(root) : of_find_node_by_path("/");
 403        if (!root)
 404                return -EINVAL;
 405
 406        pr_debug("of_platform_bus_probe()\n");
 407        pr_debug(" starting at: %s\n", root->full_name);
 408
 409        /* Do a self check of bus type, if there's a match, create children */
 410        if (of_match_node(matches, root)) {
 411                rc = of_platform_bus_create(root, matches, NULL, parent, false);
 412        } else for_each_child_of_node(root, child) {
 413                if (!of_match_node(matches, child))
 414                        continue;
 415                rc = of_platform_bus_create(child, matches, NULL, parent, false);
 416                if (rc)
 417                        break;
 418        }
 419
 420        of_node_put(root);
 421        return rc;
 422}
 423EXPORT_SYMBOL(of_platform_bus_probe);
 424
 425/**
 426 * of_platform_populate() - Populate platform_devices from device tree data
 427 * @root: parent of the first level to probe or NULL for the root of the tree
 428 * @matches: match table, NULL to use the default
 429 * @parent: parent to hook devices from, NULL for toplevel
 430 *
 431 * Similar to of_platform_bus_probe(), this function walks the device tree
 432 * and creates devices from nodes.  It differs in that it follows the modern
 433 * convention of requiring all device nodes to have a 'compatible' property,
 434 * and it is suitable for creating devices which are children of the root
 435 * node (of_platform_bus_probe will only create children of the root which
 436 * are selected by the @matches argument).
 437 *
 438 * New board support should be using this function instead of
 439 * of_platform_bus_probe().
 440 *
 441 * Returns 0 on success, < 0 on failure.
 442 */
 443int of_platform_populate(struct device_node *root,
 444                        const struct of_device_id *matches,
 445                        const struct of_dev_auxdata *lookup,
 446                        struct device *parent)
 447{
 448        struct device_node *child;
 449        int rc = 0;
 450
 451        root = root ? of_node_get(root) : of_find_node_by_path("/");
 452        if (!root)
 453                return -EINVAL;
 454
 455        for_each_child_of_node(root, child) {
 456                rc = of_platform_bus_create(child, matches, lookup, parent, true);
 457                if (rc)
 458                        break;
 459        }
 460
 461        of_node_put(root);
 462        return rc;
 463}
 464EXPORT_SYMBOL_GPL(of_platform_populate);
 465#endif /* CONFIG_OF_ADDRESS */
 466
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