drivers/dca/dca-sysfs.c

   1 /*
   2  * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; either version 2 of the License, or (at your option)
   7  * any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59
  16  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called COPYING.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/device.h>
  25 #include <linux/idr.h>
  26 #include <linux/kdev_t.h>
  27 #include <linux/err.h>
  28 #include <linux/dca.h>
  29 #include <linux/gfp.h>
  30 #include <linux/export.h>
  31
  32 static struct class *dca_class;
  33 static struct idr dca_idr;
  34 static spinlock_t dca_idr_lock;
  35
  36 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  37 {
  38         struct device *cd;
  39         static int req_count;
  40
  41         cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  42                            "requester%d", req_count++);
  43         if (IS_ERR(cd))
  44                 return PTR_ERR(cd);
  45         return 0;
  46 }
  47
  48 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  49 {
  50         device_destroy(dca_class, MKDEV(0, slot + 1));
  51 }
  52
  53 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  54 {
  55         struct device *cd;
  56         int ret;
  57
  58         idr_preload(GFP_KERNEL);
  59         spin_lock(&dca_idr_lock);
  60
  61         ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
  62         if (ret >= 0)
  63                 dca->id = ret;
  64
  65         spin_unlock(&dca_idr_lock);
  66         idr_preload_end();
  67         if (ret < 0)
  68                 return ret;
  69
  70         cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
  71         if (IS_ERR(cd)) {
  72                 spin_lock(&dca_idr_lock);
  73                 idr_remove(&dca_idr, dca->id);
  74                 spin_unlock(&dca_idr_lock);
  75                 return PTR_ERR(cd);
  76         }
  77         dca->cd = cd;
  78         return 0;
  79 }
  80
  81 void dca_sysfs_remove_provider(struct dca_provider *dca)
  82 {
  83         device_unregister(dca->cd);
  84         dca->cd = NULL;
  85         spin_lock(&dca_idr_lock);
  86         idr_remove(&dca_idr, dca->id);
  87         spin_unlock(&dca_idr_lock);
  88 }
  89
  90 int __init dca_sysfs_init(void)
  91 {
  92         idr_init(&dca_idr);
  93         spin_lock_init(&dca_idr_lock);
  94
  95         dca_class = class_create(THIS_MODULE, "dca");
  96         if (IS_ERR(dca_class)) {
  97                 idr_destroy(&dca_idr);
  98                 return PTR_ERR(dca_class);
  99         }
 100         return 0;
 101 }
 102
 103 void __exit dca_sysfs_exit(void)
 104 {
 105         class_destroy(dca_class);
 106         idr_destroy(&dca_idr);
 107 }
 108