#include <linux/string.h>
  #include <linux/kernel.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/mod_devicetable.h>
  #include <linux/slab.h>
  
  #include <asm/errno.h>
  #include "of_private.h"
  
  /**
   * of_match_device - Tell if a struct device matches an of_device_id list
   * @ids: array of of device match structures to search in
   * @dev: the of device structure to match against
   *
   * Used by a driver to check whether an platform_device present in the
   * system is in its list of supported devices.
   */
  const struct of_device_id *of_match_device(const struct of_device_id *matches,
  					   const struct device *dev)
  {
  	if ((!matches) || (!dev->of_node))
  		return NULL;
  	return of_match_node(matches, dev->of_node);
  }
  EXPORT_SYMBOL(of_match_device);
  
  struct platform_device *of_dev_get(struct platform_device *dev)
  {
  	struct device *tmp;
  
  	if (!dev)
  		return NULL;
  	tmp = get_device(&dev->dev);
  	if (tmp)
  		return to_platform_device(tmp);
  	else
  		return NULL;
  }
  EXPORT_SYMBOL(of_dev_get);
  
  void of_dev_put(struct platform_device *dev)
  {
  	if (dev)
  		put_device(&dev->dev);
  }
  EXPORT_SYMBOL(of_dev_put);
  
  int of_device_add(struct platform_device *ofdev)
  {
  	BUG_ON(ofdev->dev.of_node == NULL);
  
  	/* name and id have to be set so that the platform bus doesn't get
  	 * confused on matching */
  	ofdev->name = dev_name(&ofdev->dev);
  	ofdev->id = -1;
  
  	/* device_add will assume that this device is on the same node as
  	 * the parent. If there is no parent defined, set the node
  	 * explicitly */
  	if (!ofdev->dev.parent)
  		set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  
  	return device_add(&ofdev->dev);
  }
  
  int of_device_register(struct platform_device *pdev)
  {
  	device_initialize(&pdev->dev);
  	return of_device_add(pdev);
  }
  EXPORT_SYMBOL(of_device_register);
  
  void of_device_unregister(struct platform_device *ofdev)
  {
  	device_unregister(&ofdev->dev);
  }
  EXPORT_SYMBOL(of_device_unregister);
  
  ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
  {
  	const char *compat;
  	int cplen, i;
  	ssize_t tsize, csize, repend;
  
  	if ((!dev) || (!dev->of_node))
  		return -ENODEV;
  
  	/* Name & Type */
  	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
  			 dev->of_node->type);
  
  	/* Get compatible property if any */
  	compat = of_get_property(dev->of_node, "compatible", &cplen);
  	if (!compat)
  		return csize;
  
  	/* Find true end (we tolerate multiple \0 at the end */
  	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
  		cplen--;
  	if (!cplen)
  		return csize;
  	cplen++;
  
  	/* Check space (need cplen+1 chars including final \0) */
  	tsize = csize + cplen;
  	repend = tsize;
  
  	if (csize >= len)		/* @ the limit, all is already filled */
  		return tsize;
  
  	if (tsize >= len) {		/* limit compat list */
  		cplen = len - csize - 1;
  		repend = len;
  	}
  
  	/* Copy and do char replacement */
  	memcpy(&str[csize + 1], compat, cplen);
  	for (i = csize; i < repend; i++) {
  		char c = str[i];
  		if (c == '\0')
  			str[i] = 'C';
  		else if (c == ' ')
  			str[i] = '_';
  	}
  
  	return tsize;
  }
  
  /**
   * of_device_uevent - Display OF related uevent information
   */
  void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	const char *compat;
  	struct alias_prop *app;
  	int seen = 0, cplen, sl;
  
  	if ((!dev) || (!dev->of_node))
  		return;
  
  	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
  	add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
  	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
  		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
  
  	/* Since the compatible field can contain pretty much anything
  	 * it's not really legal to split it out with commas. We split it
  	 * up using a number of environment variables instead. */
  	compat = of_get_property(dev->of_node, "compatible", &cplen);
  	while (compat && *compat && cplen > 0) {
  		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
  		sl = strlen(compat) + 1;
  		compat += sl;
  		cplen -= sl;
  		seen++;
  	}
  	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
  
  	seen = 0;
  	mutex_lock(&of_aliases_mutex);
  	list_for_each_entry(app, &aliases_lookup, link) {
  		if (dev->of_node == app->np) {
  			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
  				       app->alias);
  			seen++;
  		}
  	}
  	mutex_unlock(&of_aliases_mutex);
  }
  
  int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
  {
  	int sl;
  
  	if ((!dev) || (!dev->of_node))
  		return -ENODEV;
  
  	/* Devicetree modalias is tricky, we add it in 2 steps */
  	if (add_uevent_var(env, "MODALIAS="))
  		return -ENOMEM;
  
  	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
  				    sizeof(env->buf) - env->buflen);
  	if (sl >= (sizeof(env->buf) - env->buflen))
  		return -ENOMEM;
  	env->buflen += sl;
  
  	return 0;
  }