1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */ 2 /************************************************************************** 3 * 4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA 5 * All Rights Reserved. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the 9 * "Software"), to deal in the Software without restriction, including 10 * without limitation the rights to use, copy, modify, merge, publish, 11 * distribute, sub license, and/or sell copies of the Software, and to 12 * permit persons to whom the Software is furnished to do so, subject to 13 * the following conditions: 14 * 15 * The above copyright notice and this permission notice (including the 16 * next paragraph) shall be included in all copies or substantial portions 17 * of the Software. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 25 * USE OR OTHER DEALINGS IN THE SOFTWARE. 26 * 27 **************************************************************************/ 28 /* 29 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> 30 * Jerome Glisse 31 */ 32 #include <linux/module.h> 33 #include <linux/device.h> 34 #include <linux/sched.h> 35 #include <drm/drm_sysfs.h> 36 37 #include "ttm_module.h" 38 39 static DECLARE_WAIT_QUEUE_HEAD(exit_q); 40 static atomic_t device_released; 41 42 static struct device_type ttm_drm_class_type = { 43 .name = "ttm", 44 /** 45 * Add pm ops here. 46 */ 47 }; 48 49 static void ttm_drm_class_device_release(struct device *dev) 50 { 51 atomic_set(&device_released, 1); 52 wake_up_all(&exit_q); 53 } 54 55 static struct device ttm_drm_class_device = { 56 .type = &ttm_drm_class_type, 57 .release = &ttm_drm_class_device_release 58 }; 59 60 struct kobject *ttm_get_kobj(void) 61 { 62 struct kobject *kobj = &ttm_drm_class_device.kobj; 63 BUG_ON(kobj == NULL); 64 return kobj; 65 } 66 67 static int __init ttm_init(void) 68 { 69 int ret; 70 71 ret = dev_set_name(&ttm_drm_class_device, "ttm"); 72 if (unlikely(ret != 0)) 73 return ret; 74 75 atomic_set(&device_released, 0); 76 ret = drm_class_device_register(&ttm_drm_class_device); 77 if (unlikely(ret != 0)) 78 goto out_no_dev_reg; 79 80 return 0; 81 out_no_dev_reg: 82 atomic_set(&device_released, 1); 83 wake_up_all(&exit_q); 84 return ret; 85 } 86 87 static void __exit ttm_exit(void) 88 { 89 drm_class_device_unregister(&ttm_drm_class_device); 90 91 /** 92 * Refuse to unload until the TTM device is released. 93 * Not sure this is 100% needed. 94 */ 95 96 wait_event(exit_q, atomic_read(&device_released) == 1); 97 } 98 99 module_init(ttm_init); 100 module_exit(ttm_exit); 101 102 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse"); 103 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)"); 104 MODULE_LICENSE("GPL and additional rights"); 105