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kernel/linux-rt-4.4.41/drivers/mtd/chips/chipreg.c 2.29 KB
5113f6f70   김현기   kernel add
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  /*
   * Registration for chip drivers
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/kmod.h>
  #include <linux/spinlock.h>
  #include <linux/slab.h>
  #include <linux/mtd/map.h>
  #include <linux/mtd/mtd.h>
  
  static DEFINE_SPINLOCK(chip_drvs_lock);
  static LIST_HEAD(chip_drvs_list);
  
  void register_mtd_chip_driver(struct mtd_chip_driver *drv)
  {
  	spin_lock(&chip_drvs_lock);
  	list_add(&drv->list, &chip_drvs_list);
  	spin_unlock(&chip_drvs_lock);
  }
  
  void unregister_mtd_chip_driver(struct mtd_chip_driver *drv)
  {
  	spin_lock(&chip_drvs_lock);
  	list_del(&drv->list);
  	spin_unlock(&chip_drvs_lock);
  }
  
  static struct mtd_chip_driver *get_mtd_chip_driver (const char *name)
  {
  	struct list_head *pos;
  	struct mtd_chip_driver *ret = NULL, *this;
  
  	spin_lock(&chip_drvs_lock);
  
  	list_for_each(pos, &chip_drvs_list) {
  		this = list_entry(pos, typeof(*this), list);
  
  		if (!strcmp(this->name, name)) {
  			ret = this;
  			break;
  		}
  	}
  	if (ret && !try_module_get(ret->module))
  		ret = NULL;
  
  	spin_unlock(&chip_drvs_lock);
  
  	return ret;
  }
  
  	/* Hide all the horrid details, like some silly person taking
  	   get_module_symbol() away from us, from the caller. */
  
  struct mtd_info *do_map_probe(const char *name, struct map_info *map)
  {
  	struct mtd_chip_driver *drv;
  	struct mtd_info *ret;
  
  	drv = get_mtd_chip_driver(name);
  
  	if (!drv && !request_module("%s", name))
  		drv = get_mtd_chip_driver(name);
  
  	if (!drv)
  		return NULL;
  
  	ret = drv->probe(map);
  
  	/* We decrease the use count here. It may have been a
  	   probe-only module, which is no longer required from this
  	   point, having given us a handle on (and increased the use
  	   count of) the actual driver code.
  	*/
  	module_put(drv->module);
  
  	return ret;
  }
  /*
   * Destroy an MTD device which was created for a map device.
   * Make sure the MTD device is already unregistered before calling this
   */
  void map_destroy(struct mtd_info *mtd)
  {
  	struct map_info *map = mtd->priv;
  
  	if (map->fldrv->destroy)
  		map->fldrv->destroy(mtd);
  
  	module_put(map->fldrv->module);
  
  	kfree(mtd);
  }
  
  EXPORT_SYMBOL(register_mtd_chip_driver);
  EXPORT_SYMBOL(unregister_mtd_chip_driver);
  EXPORT_SYMBOL(do_map_probe);
  EXPORT_SYMBOL(map_destroy);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
  MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers");