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#include <linux/gfp.h>
  30
  31static struct class *dca_class;
  32static struct idr dca_idr;
  33static spinlock_t dca_idr_lock;
  34
  35int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  36{
  37        struct device *cd;
  38        static int req_count;
  39
  40        cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  41                           "requester%d", req_count++);
  42        if (IS_ERR(cd))
  43                return PTR_ERR(cd);
  44        return 0;
  45}
  46
  47void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  48{
  49        device_destroy(dca_class, MKDEV(0, slot + 1));
  50}
  51
  52int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  53{
  54        struct device *cd;
  55        int err = 0;
  56
  57idr_try_again:
  58        if (!idr_pre_get(&dca_idr, GFP_KERNEL))
  59                return -ENOMEM;
  60        spin_lock(&dca_idr_lock);
  61        err = idr_get_new(&dca_idr, dca, &dca->id);
  62        spin_unlock(&dca_idr_lock);
  63        switch (err) {
  64        case 0:
  65                break;
  66        case -EAGAIN:
  67                goto idr_try_again;
  68        default:
  69                return err;
  70        }
  71
  72        cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
  73        if (IS_ERR(cd)) {
  74                spin_lock(&dca_idr_lock);
  75                idr_remove(&dca_idr, dca->id);
  76                spin_unlock(&dca_idr_lock);
  77                return PTR_ERR(cd);
  78        }
  79        dca->cd = cd;
  80        return 0;
  81}
  82
  83void dca_sysfs_remove_provider(struct dca_provider *dca)
  84{
  85        device_unregister(dca->cd);
  86        dca->cd = NULL;
  87        spin_lock(&dca_idr_lock);
  88        idr_remove(&dca_idr, dca->id);
  89        spin_unlock(&dca_idr_lock);
  90}
  91
  92int __init dca_sysfs_init(void)
  93{
  94        idr_init(&dca_idr);
  95        spin_lock_init(&dca_idr_lock);
  96
  97        dca_class = class_create(THIS_MODULE, "dca");
  98        if (IS_ERR(dca_class)) {
  99                idr_destroy(&dca_idr);
 100                return PTR_ERR(dca_class);
 101        }
 102        return 0;
 103}
 104
 105void __exit dca_sysfs_exit(void)
 106{
 107        class_destroy(dca_class);
 108        idr_destroy(&dca_idr);
 109}
 110
 111