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of_platform.c

/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *                 <benh@kernel.crashing.org>
 *    and          Arnd Bergmann, IBM Corp.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#undef DEBUG

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>

#include <linux/errno.h>
#include <linux/topology.h>
#include <asm/atomic.h>

struct bus_type of_platform_bus_type = {
       .uevent    = of_device_uevent,
};
EXPORT_SYMBOL(of_platform_bus_type);

static int __init of_bus_driver_init(void)
{
      return of_bus_type_init(&of_platform_bus_type, "of_platform");
}
postcore_initcall(of_bus_driver_init);

struct of_device *of_platform_device_create(struct device_node *np,
                                  const char *bus_id,
                                  struct device *parent)
{
      struct of_device *dev;

      dev = of_device_alloc(np, bus_id, parent);
      if (!dev)
            return NULL;

      dev->dma_mask = 0xffffffffUL;
      dev->dev.bus = &of_platform_bus_type;

      /* We do not fill the DMA ops for platform devices by default.
       * This is currently the responsibility of the platform code
       * to do such, possibly using a device notifier
       */

      if (of_device_register(dev) != 0) {
            of_device_free(dev);
            return NULL;
      }

      return dev;
}
EXPORT_SYMBOL(of_platform_device_create);

/**
 * of_platform_bus_create - Create an OF device for a bus node and all its
 * children. Optionally recursively instanciate matching busses.
 * @bus: device node of the bus to instanciate
 * @matches: match table, NULL to use the default, OF_NO_DEEP_PROBE to
 * disallow recursive creation of child busses
 */
static int of_platform_bus_create(const struct device_node *bus,
                          const struct of_device_id *matches,
                          struct device *parent)
{
      struct device_node *child;
      struct of_device *dev;
      int rc = 0;

      for_each_child_of_node(bus, child) {
            pr_debug("   create child: %s\n", child->full_name);
            dev = of_platform_device_create(child, NULL, parent);
            if (dev == NULL)
                  rc = -ENOMEM;
            else if (!of_match_node(matches, child))
                  continue;
            if (rc == 0) {
                  pr_debug("   and sub busses\n");
                  rc = of_platform_bus_create(child, matches, &dev->dev);
            }
            if (rc) {
                  of_node_put(child);
                  break;
            }
      }
      return rc;
}


/**
 * of_platform_bus_probe - Probe the device-tree for platform busses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table, NULL to use the default
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instanciated as devices
 * unless the specified root itself matches the bus list and is not NULL.
 */

int of_platform_bus_probe(struct device_node *root,
                    const struct of_device_id *matches,
                    struct device *parent)
{
      struct device_node *child;
      struct of_device *dev;
      int rc = 0;

      if (matches == NULL)
            matches = of_default_bus_ids;
      if (matches == OF_NO_DEEP_PROBE)
            return -EINVAL;
      if (root == NULL)
            root = of_find_node_by_path("/");
      else
            of_node_get(root);

      pr_debug("of_platform_bus_probe()\n");
      pr_debug(" starting at: %s\n", root->full_name);

      /* Do a self check of bus type, if there's a match, create
       * children
       */
      if (of_match_node(matches, root)) {
            pr_debug(" root match, create all sub devices\n");
            dev = of_platform_device_create(root, NULL, parent);
            if (dev == NULL) {
                  rc = -ENOMEM;
                  goto bail;
            }
            pr_debug(" create all sub busses\n");
            rc = of_platform_bus_create(root, matches, &dev->dev);
            goto bail;
      }
      for_each_child_of_node(root, child) {
            if (!of_match_node(matches, child))
                  continue;

            pr_debug("  match: %s\n", child->full_name);
            dev = of_platform_device_create(child, NULL, parent);
            if (dev == NULL)
                  rc = -ENOMEM;
            else
                  rc = of_platform_bus_create(child, matches, &dev->dev);
            if (rc) {
                  of_node_put(child);
                  break;
            }
      }
 bail:
      of_node_put(root);
      return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);

static int of_dev_node_match(struct device *dev, void *data)
{
      return to_of_device(dev)->node == data;
}

struct of_device *of_find_device_by_node(struct device_node *np)
{
      struct device *dev;

      dev = bus_find_device(&of_platform_bus_type,
                        NULL, np, of_dev_node_match);
      if (dev)
            return to_of_device(dev);
      return NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);

static int of_dev_phandle_match(struct device *dev, void *data)
{
      phandle *ph = data;
      return to_of_device(dev)->node->linux_phandle == *ph;
}

struct of_device *of_find_device_by_phandle(phandle ph)
{
      struct device *dev;

      dev = bus_find_device(&of_platform_bus_type,
                        NULL, &ph, of_dev_phandle_match);
      if (dev)
            return to_of_device(dev);
      return NULL;
}
EXPORT_SYMBOL(of_find_device_by_phandle);

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