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 __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 */
 139struct 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                WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
 172        }
 173
 174        dev->dev.of_node = of_node_get(np);
 175#if defined(CONFIG_MICROBLAZE)
 176        dev->dev.dma_mask = &dev->archdata.dma_mask;
 177#endif
 178        dev->dev.parent = parent;
 179
 180        if (bus_id)
 181                dev_set_name(&dev->dev, "%s", bus_id);
 182        else
 183                of_device_make_bus_id(&dev->dev);
 184
 185        return dev;
 186}
 187EXPORT_SYMBOL(of_device_alloc);
 188
 189/**
 190 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 191 * @np: pointer to node to create device for
 192 * @bus_id: name to assign device
 193 * @platform_data: pointer to populate platform_data pointer with
 194 * @parent: Linux device model parent device.
 195 *
 196 * Returns pointer to created platform device, or NULL if a device was not
 197 * registered.  Unavailable devices will not get registered.
 198 */
 199struct platform_device *of_platform_device_create_pdata(
 200                                        struct device_node *np,
 201                                        const char *bus_id,
 202                                        void *platform_data,
 203                                        struct device *parent)
 204{
 205        struct platform_device *dev;
 206
 207        if (!of_device_is_available(np))
 208                return NULL;
 209
 210        dev = of_device_alloc(np, bus_id, parent);
 211        if (!dev)
 212                return NULL;
 213
 214#if defined(CONFIG_MICROBLAZE)
 215        dev->archdata.dma_mask = 0xffffffffUL;
 216#endif
 217        dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 218        dev->dev.bus = &platform_bus_type;
 219        dev->dev.platform_data = platform_data;
 220
 221        /* We do not fill the DMA ops for platform devices by default.
 222         * This is currently the responsibility of the platform code
 223         * to do such, possibly using a device notifier
 224         */
 225
 226        if (of_device_add(dev) != 0) {
 227                platform_device_put(dev);
 228                return NULL;
 229        }
 230
 231        return dev;
 232}
 233
 234/**
 235 * of_platform_device_create - Alloc, initialize and register an of_device
 236 * @np: pointer to node to create device for
 237 * @bus_id: name to assign device
 238 * @parent: Linux device model parent device.
 239 *
 240 * Returns pointer to created platform device, or NULL if a device was not
 241 * registered.  Unavailable devices will not get registered.
 242 */
 243struct platform_device *of_platform_device_create(struct device_node *np,
 244                                            const char *bus_id,
 245                                            struct device *parent)
 246{
 247        return of_platform_device_create_pdata(np, bus_id, NULL, parent);
 248}
 249EXPORT_SYMBOL(of_platform_device_create);
 250
 251#ifdef CONFIG_ARM_AMBA
 252static struct amba_device *of_amba_device_create(struct device_node *node,
 253                                                 const char *bus_id,
 254                                                 void *platform_data,
 255                                                 struct device *parent)
 256{
 257        struct amba_device *dev;
 258        const void *prop;
 259        int i, ret;
 260
 261        pr_debug("Creating amba device %s\n", node->full_name);
 262
 263        if (!of_device_is_available(node))
 264                return NULL;
 265
 266        dev = amba_device_alloc(NULL, 0, 0);
 267        if (!dev)
 268                return NULL;
 269
 270        /* setup generic device info */
 271        dev->dev.coherent_dma_mask = ~0;
 272        dev->dev.of_node = of_node_get(node);
 273        dev->dev.parent = parent;
 274        dev->dev.platform_data = platform_data;
 275        if (bus_id)
 276                dev_set_name(&dev->dev, "%s", bus_id);
 277        else
 278                of_device_make_bus_id(&dev->dev);
 279
 280        /* setup amba-specific device info */
 281        dev->dma_mask = ~0;
 282
 283        /* Allow the HW Peripheral ID to be overridden */
 284        prop = of_get_property(node, "arm,primecell-periphid", NULL);
 285        if (prop)
 286                dev->periphid = of_read_ulong(prop, 1);
 287
 288        /* Decode the IRQs and address ranges */
 289        for (i = 0; i < AMBA_NR_IRQS; i++)
 290                dev->irq[i] = irq_of_parse_and_map(node, i);
 291
 292        ret = of_address_to_resource(node, 0, &dev->res);
 293        if (ret)
 294                goto err_free;
 295
 296        ret = amba_device_add(dev, &iomem_resource);
 297        if (ret)
 298                goto err_free;
 299
 300        return dev;
 301
 302err_free:
 303        amba_device_put(dev);
 304        return NULL;
 305}
 306#else /* CONFIG_ARM_AMBA */
 307static struct amba_device *of_amba_device_create(struct device_node *node,
 308                                                 const char *bus_id,
 309                                                 void *platform_data,
 310                                                 struct device *parent)
 311{
 312        return NULL;
 313}
 314#endif /* CONFIG_ARM_AMBA */
 315
 316/**
 317 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 318 */
 319static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
 320                                 struct device_node *np)
 321{
 322        struct resource res;
 323
 324        if (!lookup)
 325                return NULL;
 326
 327        for(; lookup->compatible != NULL; lookup++) {
 328                if (!of_device_is_compatible(np, lookup->compatible))
 329                        continue;
 330                if (!of_address_to_resource(np, 0, &res))
 331                        if (res.start != lookup->phys_addr)
 332                                continue;
 333                pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
 334                return lookup;
 335        }
 336
 337        return NULL;
 338}
 339
 340/**
 341 * of_platform_bus_create() - Create a device for a node and its children.
 342 * @bus: device node of the bus to instantiate
 343 * @matches: match table for bus nodes
 344 * @lookup: auxdata table for matching id and platform_data with device nodes
 345 * @parent: parent for new device, or NULL for top level.
 346 * @strict: require compatible property
 347 *
 348 * Creates a platform_device for the provided device_node, and optionally
 349 * recursively create devices for all the child nodes.
 350 */
 351static int of_platform_bus_create(struct device_node *bus,
 352                                  const struct of_device_id *matches,
 353                                  const struct of_dev_auxdata *lookup,
 354                                  struct device *parent, bool strict)
 355{
 356        const struct of_dev_auxdata *auxdata;
 357        struct device_node *child;
 358        struct platform_device *dev;
 359        const char *bus_id = NULL;
 360        void *platform_data = NULL;
 361        int rc = 0;
 362
 363        /* Make sure it has a compatible property */
 364        if (strict && (!of_get_property(bus, "compatible", NULL))) {
 365                pr_debug("%s() - skipping %s, no compatible prop\n",
 366                         __func__, bus->full_name);
 367                return 0;
 368        }
 369
 370        auxdata = of_dev_lookup(lookup, bus);
 371        if (auxdata) {
 372                bus_id = auxdata->name;
 373                platform_data = auxdata->platform_data;
 374        }
 375
 376        if (of_device_is_compatible(bus, "arm,primecell")) {
 377                of_amba_device_create(bus, bus_id, platform_data, parent);
 378                return 0;
 379        }
 380
 381        dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
 382        if (!dev || !of_match_node(matches, bus))
 383                return 0;
 384
 385        for_each_child_of_node(bus, child) {
 386                pr_debug("   create child: %s\n", child->full_name);
 387                rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
 388                if (rc) {
 389                        of_node_put(child);
 390                        break;
 391                }
 392        }
 393        return rc;
 394}
 395
 396/**
 397 * of_platform_bus_probe() - Probe the device-tree for platform buses
 398 * @root: parent of the first level to probe or NULL for the root of the tree
 399 * @matches: match table for bus nodes
 400 * @parent: parent to hook devices from, NULL for toplevel
 401 *
 402 * Note that children of the provided root are not instantiated as devices
 403 * unless the specified root itself matches the bus list and is not NULL.
 404 */
 405int of_platform_bus_probe(struct device_node *root,
 406                          const struct of_device_id *matches,
 407                          struct device *parent)
 408{
 409        struct device_node *child;
 410        int rc = 0;
 411
 412        root = root ? of_node_get(root) : of_find_node_by_path("/");
 413        if (!root)
 414                return -EINVAL;
 415
 416        pr_debug("of_platform_bus_probe()\n");
 417        pr_debug(" starting at: %s\n", root->full_name);
 418
 419        /* Do a self check of bus type, if there's a match, create children */
 420        if (of_match_node(matches, root)) {
 421                rc = of_platform_bus_create(root, matches, NULL, parent, false);
 422        } else for_each_child_of_node(root, child) {
 423                if (!of_match_node(matches, child))
 424                        continue;
 425                rc = of_platform_bus_create(child, matches, NULL, parent, false);
 426                if (rc)
 427                        break;
 428        }
 429
 430        of_node_put(root);
 431        return rc;
 432}
 433EXPORT_SYMBOL(of_platform_bus_probe);
 434
 435/**
 436 * of_platform_populate() - Populate platform_devices from device tree data
 437 * @root: parent of the first level to probe or NULL for the root of the tree
 438 * @matches: match table, NULL to use the default
 439 * @parent: parent to hook devices from, NULL for toplevel
 440 *
 441 * Similar to of_platform_bus_probe(), this function walks the device tree
 442 * and creates devices from nodes.  It differs in that it follows the modern
 443 * convention of requiring all device nodes to have a 'compatible' property,
 444 * and it is suitable for creating devices which are children of the root
 445 * node (of_platform_bus_probe will only create children of the root which
 446 * are selected by the @matches argument).
 447 *
 448 * New board support should be using this function instead of
 449 * of_platform_bus_probe().
 450 *
 451 * Returns 0 on success, < 0 on failure.
 452 */
 453int of_platform_populate(struct device_node *root,
 454                        const struct of_device_id *matches,
 455                        const struct of_dev_auxdata *lookup,
 456                        struct device *parent)
 457{
 458        struct device_node *child;
 459        int rc = 0;
 460
 461        root = root ? of_node_get(root) : of_find_node_by_path("/");
 462        if (!root)
 463                return -EINVAL;
 464
 465        for_each_child_of_node(root, child) {
 466                rc = of_platform_bus_create(child, matches, lookup, parent, true);
 467                if (rc)
 468                        break;
 469        }
 470
 471        of_node_put(root);
 472        return rc;
 473}
 474EXPORT_SYMBOL_GPL(of_platform_populate);
 475#endif /* CONFIG_OF_ADDRESS */
 476
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