xref: /openbmc/linux/drivers/gpu/drm/ttm/ttm_module.c (revision 9cfc5c90)
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,
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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 static 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