/*
   * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc., 59
   * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   *
   * The full GNU General Public License is included in this distribution in the
   * file called COPYING.
   */

  #include <linux/kernel.h>
  #include <linux/spinlock.h>
  #include <linux/device.h>
  #include <linux/idr.h>
  #include <linux/kdev_t.h>
  #include <linux/err.h>
  #include <linux/dca.h>

  #include <linux/gfp.h>

  #include <linux/export.h>

  
  static struct class *dca_class;
  static struct idr dca_idr;
  static spinlock_t dca_idr_lock;
  
  int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  {

  	struct device *cd;

  	static int req_count;

  	cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  			   "requester%d", req_count++);

  	if (IS_ERR(cd))
  		return PTR_ERR(cd);
  	return 0;
  }
  
  void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  {

  	device_destroy(dca_class, MKDEV(0, slot + 1));

  }
  
  int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  {

  	struct device *cd;

  	int err = 0;
  
  idr_try_again:
  	if (!idr_pre_get(&dca_idr, GFP_KERNEL))
  		return -ENOMEM;
  	spin_lock(&dca_idr_lock);
  	err = idr_get_new(&dca_idr, dca, &dca->id);
  	spin_unlock(&dca_idr_lock);
  	switch (err) {
  	case 0:
  		break;
  	case -EAGAIN:
  		goto idr_try_again;
  	default:
  		return err;
  	}

  	cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);

  	if (IS_ERR(cd)) {
  		spin_lock(&dca_idr_lock);
  		idr_remove(&dca_idr, dca->id);
  		spin_unlock(&dca_idr_lock);
  		return PTR_ERR(cd);
  	}
  	dca->cd = cd;
  	return 0;
  }
  
  void dca_sysfs_remove_provider(struct dca_provider *dca)
  {

  	device_unregister(dca->cd);

  	dca->cd = NULL;
  	spin_lock(&dca_idr_lock);
  	idr_remove(&dca_idr, dca->id);
  	spin_unlock(&dca_idr_lock);
  }
  
  int __init dca_sysfs_init(void)
  {
  	idr_init(&dca_idr);
  	spin_lock_init(&dca_idr_lock);
  
  	dca_class = class_create(THIS_MODULE, "dca");
  	if (IS_ERR(dca_class)) {
  		idr_destroy(&dca_idr);
  		return PTR_ERR(dca_class);
  	}
  	return 0;
  }
  
  void __exit dca_sysfs_exit(void)
  {
  	class_destroy(dca_class);
  	idr_destroy(&dca_idr);
  }