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ttm_module.c revision 1.1.1.1.12.2 
      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 
     37 static DECLARE_WAIT_QUEUE_HEAD(exit_q);
     38 atomic_t device_released;
     39 
     40 static struct device_type ttm_drm_class_type = {
     41 	.name = "ttm",
     42 	/**
     43 	 * Add pm ops here.
     44 	 */
     45 };
     46 
     47 static void ttm_drm_class_device_release(struct device *dev)
     48 {
     49 	atomic_set(&device_released, 1);
     50 	wake_up_all(&exit_q);
     51 }
     52 
     53 static struct device ttm_drm_class_device = {
     54 	.type = &ttm_drm_class_type,
     55 	.release = &ttm_drm_class_device_release
     56 };
     57 
     58 struct 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 
     65 static 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;
     79 out_no_dev_reg:
     80 	atomic_set(&device_released, 1);
     81 	wake_up_all(&exit_q);
     82 	return ret;
     83 }
     84 
     85 static 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 
     97 module_init(ttm_init);
     98 module_exit(ttm_exit);
     99 
    100 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
    101 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
    102 MODULE_LICENSE("GPL and additional rights");
    103