LXR linux/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
  30static struct class *dca_class;
  31static struct idr dca_idr;
  32static spinlock_t dca_idr_lock;
  33
  34int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  35{
  36        struct device *cd;
  37        static int req_count;
  38
  39        cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  40                           "requester%d", req_count++);
  41        if (IS_ERR(cd))
  42                return PTR_ERR(cd);
  43        return 0;
  44}
  45
  46void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  47{
  48        device_destroy(dca_class, MKDEV(0, slot + 1));
  49}
  50
  51int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  52{
  53        struct device *cd;
  54        int err = 0;
  55
  56idr_try_again:
  57        if (!idr_pre_get(&dca_idr, GFP_KERNEL))
  58                return -ENOMEM;
  59        spin_lock(&dca_idr_lock);
  60        err = idr_get_new(&dca_idr, dca, &dca->id);
  61        spin_unlock(&dca_idr_lock);
  62        switch (err) {
  63        case 0:
  64                break;
  65        case -EAGAIN:
  66                goto idr_try_again;
  67        default:
  68                return err;
  69        }
  70
  71        cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
  72        if (IS_ERR(cd)) {
  73                spin_lock(&dca_idr_lock);
  74                idr_remove(&dca_idr, dca->id);
  75                spin_unlock(&dca_idr_lock);
  76                return PTR_ERR(cd);
  77        }
  78        dca->cd = cd;
  79        return 0;
  80}
  81
  82void dca_sysfs_remove_provider(struct dca_provider *dca)
  83{
  84        device_unregister(dca->cd);
  85        dca->cd = NULL;
  86        spin_lock(&dca_idr_lock);
  87        idr_remove(&dca_idr, dca->id);
  88        spin_unlock(&dca_idr_lock);
  89}
  90
  91int __init dca_sysfs_init(void)
  92{
  93        idr_init(&dca_idr);
  94        spin_lock_init(&dca_idr_lock);
  95
  96        dca_class = class_create(THIS_MODULE, "dca");
  97        if (IS_ERR(dca_class)) {
  98                idr_destroy(&dca_idr);
  99                return PTR_ERR(dca_class);
 100        }
 101        return 0;
 102}
 103
 104void __exit dca_sysfs_exit(void)
 105{
 106        class_destroy(dca_class);
 107        idr_destroy(&dca_idr);
 108}
 109
 110