LXR linux/drivers/gpu/drm/ttm/ttm

   1/**************************************************************************
   2 *
   3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4 * All Rights Reserved.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a
   7 * copy of this software and associated documentation files (the
   8 * "Software"), to deal in the Software without restriction, including
   9 * without limitation the rights to use, copy, modify, merge, publish,
  10 * distribute, sub license, and/or sell copies of the Software, and to
  11 * permit persons to whom the Software is furnished to do so, subject to
  12 * the following conditions:
  13 *
  14 * The above copyright notice and this permission notice (including the
  15 * next paragraph) shall be included in all copies or substantial portions
  16 * of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25 *
  26 **************************************************************************/
  27/*
  28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29 *          Jerome Glisse
  30 */
  31#include <linux/module.h>
  32#include <linux/device.h>
  33#include <linux/sched.h>
  34#include <drm/ttm/ttm_module.h>
  35#include <drm/drm_sysfs.h>
  36
  37static DECLARE_WAIT_QUEUE_HEAD(exit_q);
  38atomic_t device_released;
  39
  40static struct device_type ttm_drm_class_type = {
  41        .name = "ttm",
  42        /**
  43         * Add pm ops here.
  44         */
  45};
  46
  47static void ttm_drm_class_device_release(struct device *dev)
  48{
  49        atomic_set(&device_released, 1);
  50        wake_up_all(&exit_q);
  51}
  52
  53static struct device ttm_drm_class_device = {
  54        .type = &ttm_drm_class_type,
  55        .release = &ttm_drm_class_device_release
  56};
  57
  58struct kobject *ttm_get_kobj(void)
  59{
  60        struct kobject *kobj = &ttm_drm_class_device.kobj;
  61        BUG_ON(kobj == NULL);
  62        return kobj;
  63}
  64
  65static int __init ttm_init(void)
  66{
  67        int ret;
  68
  69        ret = dev_set_name(&ttm_drm_class_device, "ttm");
  70        if (unlikely(ret != 0))
  71                return ret;
  72
  73        atomic_set(&device_released, 0);
  74        ret = drm_class_device_register(&ttm_drm_class_device);
  75        if (unlikely(ret != 0))
  76                goto out_no_dev_reg;
  77
  78        return 0;
  79out_no_dev_reg:
  80        atomic_set(&device_released, 1);
  81        wake_up_all(&exit_q);
  82        return ret;
  83}
  84
  85static void __exit ttm_exit(void)
  86{
  87        drm_class_device_unregister(&ttm_drm_class_device);
  88
  89        /**
  90         * Refuse to unload until the TTM device is released.
  91         * Not sure this is 100% needed.
  92         */
  93
  94        wait_event(exit_q, atomic_read(&device_released) == 1);
  95}
  96
  97module_init(ttm_init);
  98module_exit(ttm_exit);
  99
 100MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
 101MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
 102MODULE_LICENSE("GPL and additional rights");
 103