gpio_chip1:gpio_chip@120d1000{
  compatible="arm,p1061","arm,primecell"
  reg=<0X120d10000X1000>；
  interrupts=<0174>；
  clocks=<&clock H13516DV300_SYSAPB_CLK>；
  clock-names="apb_pclk"·
  #gpio-cells=<2>；
  status="disabled";
};

/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *       <benh@kernel.crashing.org>
 *    and    Arnd Bergmann, IBM Corp.
 *    Merged from powerpc/kernel/of_platform.c and
 *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
 *
 *  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.
 *
 */
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
const struct of_device_id of_default_bus_match_table[] = {
  { .compatible = "simple-bus", },
  { .compatible = "simple-mfd", },
#ifdef CONFIG_ARM_AMBA
  { .compatible = "arm,amba-bus", },
#endif /* CONFIG_ARM_AMBA */
  {} /* Empty terminated list */
};
static int of_dev_node_match(struct device *dev, void *data)
{
  return dev->of_node == data;
}
/**
 * of_find_device_by_node - Find the platform_device associated with a node
 * @np: Pointer to device tree node
 *
 * Returns platform_device pointer, or NULL if not found
 */
struct platform_device *of_find_device_by_node(struct device_node *np)
{
  struct device *dev;
  dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
  return dev ? to_platform_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);
#ifdef CONFIG_OF_ADDRESS
/*
 * The following routines scan a subtree and registers a device for
 * each applicable node.
 *
 * Note: sparc doesn't use these routines because it has a different
 * mechanism for creating devices from device tree nodes.
 */
/**
 * of_device_make_bus_id - Use the device node data to assign a unique name
 * @dev: pointer to device structure that is linked to a device tree node
 *
 * This routine will first try using the translated bus address to
 * derive a unique name. If it cannot, then it will prepend names from
 * parent nodes until a unique name can be derived.
 */
void of_device_make_bus_id(struct device *dev)
{
  struct device_node *node = dev->of_node;
  const __be32 *reg;
  u64 addr;
  /* Construct the name, using parent nodes if necessary to ensure uniqueness */
  while (node->parent) {
    /*
     * If the address can be translated, then that is as much
     * uniqueness as we need. Make it the first component and return
     */
    reg = of_get_property(node, "reg", NULL);
    if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
      dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
             (unsigned long long)addr, node->name,
             dev_name(dev));
      return;
    }
    /* format arguments only used if dev_name() resolves to NULL */
    dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
           strrchr(node->full_name, '/') + 1, dev_name(dev));
    node = node->parent;
  }
}
/**
 * of_device_alloc - Allocate and initialize an of_device
 * @np: device node to assign to device
 * @bus_id: Name to assign to the device.  May be null to use default name.
 * @parent: Parent device.
 */
struct platform_device *of_device_alloc(struct device_node *np,
          const char *bus_id,
          struct device *parent)
{
  struct platform_device *dev;
  int rc, i, num_reg = 0, num_irq;
  struct resource *res, temp_res;
  dev = platform_device_alloc("", -1);
  if (!dev)
    return NULL;
  /* count the io and irq resources */
  while (of_address_to_resource(np, num_reg, &temp_res) == 0)
    num_reg++;
  num_irq = of_irq_count(np);
  /* Populate the resource table */
  if (num_irq || num_reg) {
    res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
    if (!res) {
      platform_device_put(dev);
      return NULL;
    }
    dev->num_resources = num_reg + num_irq;
    dev->resource = res;
    for (i = 0; i < num_reg; i++, res++) {
      rc = of_address_to_resource(np, i, res);
      WARN_ON(rc);
    }
    if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
      pr_debug("not all legacy IRQ resources mapped for %s\n",
         np->name);
  }
  dev->dev.of_node = of_node_get(np);
  dev->dev.parent = parent ? : &platform_bus;
  if (bus_id)
    dev_set_name(&dev->dev, "%s", bus_id);
  else
    of_device_make_bus_id(&dev->dev);
  return dev;
}
EXPORT_SYMBOL(of_device_alloc);
static void of_dma_deconfigure(struct device *dev)
{
  arch_teardown_dma_ops(dev);
}
/**
 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @platform_data: pointer to populate platform_data pointer with
 * @parent: Linux device model parent device.
 *
 * Returns pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
static struct platform_device *of_platform_device_create_pdata(
          struct device_node *np,
          const char *bus_id,
          void *platform_data,
          struct device *parent)
{
  struct platform_device *dev;
  if (!of_device_is_available(np) ||
      of_node_test_and_set_flag(np, OF_POPULATED))
    return NULL;
  dev = of_device_alloc(np, bus_id, parent);
  if (!dev)
    goto err_clear_flag;
  dev->dev.bus = &platform_bus_type;
  dev->dev.platform_data = platform_data;
  of_dma_configure(&dev->dev, dev->dev.of_node);
  if (of_device_add(dev) != 0) {
    of_dma_deconfigure(&dev->dev);
    platform_device_put(dev);
    goto err_clear_flag;
  }
  return dev;
err_clear_flag:
  of_node_clear_flag(np, OF_POPULATED);
  return NULL;
}
/**
 * of_platform_device_create - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @parent: Linux device model parent device.
 *
 * Returns pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
struct platform_device *of_platform_device_create(struct device_node *np,
              const char *bus_id,
              struct device *parent)
{
  return of_platform_device_create_pdata(np, bus_id, NULL, parent);
}
EXPORT_SYMBOL(of_platform_device_create);
#ifdef CONFIG_ARM_AMBA
static struct amba_device *of_amba_device_create(struct device_node *node,
             const char *bus_id,
             void *platform_data,
             struct device *parent)
{
  struct amba_device *dev;
  const void *prop;
  int i, ret;
  pr_debug("Creating amba device %s\n", node->full_name);
  if (!of_device_is_available(node) ||
      of_node_test_and_set_flag(node, OF_POPULATED))
    return NULL;
  dev = amba_device_alloc(NULL, 0, 0);
  if (!dev) {
    pr_err("%s(): amba_device_alloc() failed for %s\n",
           __func__, node->full_name);
    goto err_clear_flag;
  }
  /* setup generic device info */
  dev->dev.of_node = of_node_get(node);
  dev->dev.parent = parent ? : &platform_bus;
  dev->dev.platform_data = platform_data;
  if (bus_id)
    dev_set_name(&dev->dev, "%s", bus_id);
  else
    of_device_make_bus_id(&dev->dev);
  of_dma_configure(&dev->dev, dev->dev.of_node);
  /* Allow the HW Peripheral ID to be overridden */
  prop = of_get_property(node, "arm,primecell-periphid", NULL);
  if (prop)
    dev->periphid = of_read_ulong(prop, 1);
  /* Decode the IRQs and address ranges */
  for (i = 0; i < AMBA_NR_IRQS; i++)
    dev->irq[i] = irq_of_parse_and_map(node, i);
  ret = of_address_to_resource(node, 0, &dev->res);
  if (ret) {
    pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
           __func__, ret, node->full_name);
    goto err_free;
  }
  ret = amba_device_add(dev, &iomem_resource);
  if (ret) {
    pr_err("%s(): amba_device_add() failed (%d) for %s\n",
           __func__, ret, node->full_name);
    goto err_free;
  }
  return dev;
err_free:
  amba_device_put(dev);
err_clear_flag:
  of_node_clear_flag(node, OF_POPULATED);
  return NULL;
}
#else /* CONFIG_ARM_AMBA */
static struct amba_device *of_amba_device_create(struct device_node *node,
             const char *bus_id,
             void *platform_data,
             struct device *parent)
{
  return NULL;
}
#endif /* CONFIG_ARM_AMBA */
/**
 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 */
static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
         struct device_node *np)
{
  struct resource res;
  if (!lookup)
    return NULL;
  for(; lookup->compatible != NULL; lookup++) {
    if (!of_device_is_compatible(np, lookup->compatible))
      continue;
    if (!of_address_to_resource(np, 0, &res))
      if (res.start != lookup->phys_addr)
        continue;
    pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
    return lookup;
  }
  return NULL;
}
/**
 * of_platform_bus_create() - Create a device for a node and its children.
 * @bus: device node of the bus to instantiate
 * @matches: match table for bus nodes
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent for new device, or NULL for top level.
 * @strict: require compatible property
 *
 * Creates a platform_device for the provided device_node, and optionally
 * recursively create devices for all the child nodes.
 */
static int of_platform_bus_create(struct device_node *bus,
          const struct of_device_id *matches,
          const struct of_dev_auxdata *lookup,
          struct device *parent, bool strict)
{
  const struct of_dev_auxdata *auxdata;
  struct device_node *child;
  struct platform_device *dev;
  const char *bus_id = NULL;
  void *platform_data = NULL;
  int rc = 0;
  /* Make sure it has a compatible property */
  if (strict && (!of_get_property(bus, "compatible", NULL))) {
    pr_debug("%s() - skipping %s, no compatible prop\n",
       __func__, bus->full_name);
    return 0;
  }
  auxdata = of_dev_lookup(lookup, bus);
  if (auxdata) {
    bus_id = auxdata->name;
    platform_data = auxdata->platform_data;
  }
  if (of_device_is_compatible(bus, "arm,primecell")) {
    /*
     * Don't return an error here to keep compatibility with older
     * device tree files.
     */
    of_amba_device_create(bus, bus_id, platform_data, parent);
    return 0;
  }
  dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
  if (!dev || !of_match_node(matches, bus))
    return 0;
  for_each_child_of_node(bus, child) {
    pr_debug("   create child: %s\n", child->full_name);
    rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
    if (rc) {
      of_node_put(child);
      break;
    }
  }
  of_node_set_flag(bus, OF_POPULATED_BUS);
  return rc;
}
/**
 * of_platform_bus_probe() - Probe the device-tree for platform buses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table for bus nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instantiated 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;
  int rc = 0;
  root = root ? of_node_get(root) : of_find_node_by_path("/");
  if (!root)
    return -EINVAL;
  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)) {
    rc = of_platform_bus_create(root, matches, NULL, parent, false);
  } else for_each_child_of_node(root, child) {
    if (!of_match_node(matches, child))
      continue;
    rc = of_platform_bus_create(child, matches, NULL, parent, false);
    if (rc)
      break;
  }
  of_node_put(root);
  return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);
/**
 * of_platform_populate() - Populate platform_devices from device tree data
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table, NULL to use the default
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Similar to of_platform_bus_probe(), this function walks the device tree
 * and creates devices from nodes.  It differs in that it follows the modern
 * convention of requiring all device nodes to have a 'compatible' property,
 * and it is suitable for creating devices which are children of the root
 * node (of_platform_bus_probe will only create children of the root which
 * are selected by the @matches argument).
 *
 * New board support should be using this function instead of
 * of_platform_bus_probe().
 *
 * Returns 0 on success, < 0 on failure.
 */
int of_platform_populate(struct device_node *root,
      const struct of_device_id *matches,
      const struct of_dev_auxdata *lookup,
      struct device *parent)
{
  struct device_node *child;
  int rc = 0;
  root = root ? of_node_get(root) : of_find_node_by_path("/");
  if (!root)
    return -EINVAL;
  for_each_child_of_node(root, child) {
    rc = of_platform_bus_create(child, matches, lookup, parent, true);
    if (rc)
      break;
  }
  of_node_set_flag(root, OF_POPULATED_BUS);
  of_node_put(root);
  return rc;
}
EXPORT_SYMBOL_GPL(of_platform_populate);
static int of_platform_device_destroy(struct device *dev, void *data)
{
  /* Do not touch devices not populated from the device tree */
  if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
    return 0;
  /* Recurse for any nodes that were treated as busses */
  if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
    device_for_each_child(dev, NULL, of_platform_device_destroy);
  if (dev->bus == &platform_bus_type)
    platform_device_unregister(to_platform_device(dev));
#ifdef CONFIG_ARM_AMBA
  else if (dev->bus == &amba_bustype)
    amba_device_unregister(to_amba_device(dev));
#endif
  of_dma_deconfigure(dev);
  of_node_clear_flag(dev->of_node, OF_POPULATED);
  of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
  return 0;
}
/**
 * of_platform_depopulate() - Remove devices populated from device tree
 * @parent: device which children will be removed
 *
 * Complementary to of_platform_populate(), this function removes children
 * of the given device (and, recurrently, their children) that have been
 * created from their respective device tree nodes (and only those,
 * leaving others - eg. manually created - unharmed).
 *
 * Returns 0 when all children devices have been removed or
 * -EBUSY when some children remained.
 */
void of_platform_depopulate(struct device *parent)
{
  if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
    device_for_each_child(parent, NULL, of_platform_device_destroy);
    of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
  }
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);
#ifdef CONFIG_OF_DYNAMIC
static int of_platform_notify(struct notifier_block *nb,
        unsigned long action, void *arg)
{
  struct of_reconfig_data *rd = arg;
  struct platform_device *pdev_parent, *pdev;
  bool children_left;
  switch (of_reconfig_get_state_change(action, rd)) {
  case OF_RECONFIG_CHANGE_ADD:
    /* verify that the parent is a bus */
    if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
      return NOTIFY_OK; /* not for us */
    /* already populated? (driver using of_populate manually) */
    if (of_node_check_flag(rd->dn, OF_POPULATED))
      return NOTIFY_OK;
    /* pdev_parent may be NULL when no bus platform device */
    pdev_parent = of_find_device_by_node(rd->dn->parent);
    pdev = of_platform_device_create(rd->dn, NULL,
        pdev_parent ? &pdev_parent->dev : NULL);
    of_dev_put(pdev_parent);
    if (pdev == NULL) {
      pr_err("%s: failed to create for '%s'\n",
          __func__, rd->dn->full_name);
      /* of_platform_device_create tosses the error code */
      return notifier_from_errno(-EINVAL);
    }
    break;
  case OF_RECONFIG_CHANGE_REMOVE:
    /* already depopulated? */
    if (!of_node_check_flag(rd->dn, OF_POPULATED))
      return NOTIFY_OK;
    /* find our device by node */
    pdev = of_find_device_by_node(rd->dn);
    if (pdev == NULL)
      return NOTIFY_OK; /* no? not meant for us */
    /* unregister takes one ref away */
    of_platform_device_destroy(&pdev->dev, &children_left);
    /* and put the reference of the find */
    of_dev_put(pdev);
    break;
  }
  return NOTIFY_OK;
}
static struct notifier_block platform_of_notifier = {
  .notifier_call = of_platform_notify,
};
void of_platform_register_reconfig_notifier(void)
{
  WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
}
#endif /* CONFIG_OF_DYNAMIC */
#endif /* CONFIG_OF_ADDRESS */