1 /* drm_stub.h -- -*- linux-c -*-
2 * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
3 *
4 * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
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 "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the next
15 * paragraph) shall be included in all copies or substantial portions of the
16 * 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 NONINFRINGEMENT. IN NO EVENT SHALL
21 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 * DEALINGS IN THE SOFTWARE.
25 *
26 * Authors:
27 * Rickard E. (Rik) Faith <faith@valinux.com>
28 *
29 */
30
31 #include "drmP.h"
32
33 #define DRM_STUB_MAXCARDS 16 /* Enough for one machine */
34
35 static struct drm_stub_list {
36 const char *name;
37 struct file_operations *fops;
38 struct proc_dir_entry *dev_root;
39 } *DRM(stub_list);
40
41 static struct proc_dir_entry *DRM(stub_root);
42
43 static struct drm_stub_info {
44 int (*info_register)(const char *name, struct file_operations *fops,
45 drm_device_t *dev);
46 int (*info_unregister)(int minor);
47 } DRM(stub_info);
48
DRM(stub_open)49 static int DRM(stub_open)(struct inode *inode, struct file *filp)
50 {
51 int minor = minor(inode->i_rdev);
52 int err = -ENODEV;
53 struct file_operations *old_fops;
54
55 if (minor < 0 || minor >=DRM_STUB_MAXCARDS) return -ENODEV;
56 if (!DRM(stub_list) || !DRM(stub_list)[minor].fops) return -ENODEV;
57 old_fops = filp->f_op;
58 filp->f_op = fops_get(DRM(stub_list)[minor].fops);
59 if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
60 fops_put(filp->f_op);
61 filp->f_op = fops_get(old_fops);
62 }
63 fops_put(old_fops);
64
65 return err;
66 }
67
68 static struct file_operations DRM(stub_fops) = {
69 .owner = THIS_MODULE,
70 .open = DRM(stub_open)
71 };
72
DRM(stub_getminor)73 static int DRM(stub_getminor)(const char *name, struct file_operations *fops,
74 drm_device_t *dev)
75 {
76 int i;
77
78 if (!DRM(stub_list)) {
79 DRM(stub_list) = DRM(alloc)(sizeof(*DRM(stub_list))
80 * DRM_STUB_MAXCARDS, DRM_MEM_STUB);
81 if(!DRM(stub_list)) return -1;
82 for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
83 DRM(stub_list)[i].name = NULL;
84 DRM(stub_list)[i].fops = NULL;
85 }
86 }
87 for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
88 if (!DRM(stub_list)[i].fops) {
89 DRM(stub_list)[i].name = name;
90 DRM(stub_list)[i].fops = fops;
91 DRM(stub_root) = DRM(proc_init)(dev, i, DRM(stub_root),
92 &DRM(stub_list)[i]
93 .dev_root);
94 return i;
95 }
96 }
97 return -1;
98 }
99
DRM(stub_putminor)100 static int DRM(stub_putminor)(int minor)
101 {
102 if (minor < 0 || minor >= DRM_STUB_MAXCARDS) return -1;
103 DRM(stub_list)[minor].name = NULL;
104 DRM(stub_list)[minor].fops = NULL;
105 DRM(proc_cleanup)(minor, DRM(stub_root),
106 DRM(stub_list)[minor].dev_root);
107 if (minor) {
108 inter_module_put("drm");
109 } else {
110 inter_module_unregister("drm");
111 DRM(free)(DRM(stub_list),
112 sizeof(*DRM(stub_list)) * DRM_STUB_MAXCARDS,
113 DRM_MEM_STUB);
114 unregister_chrdev(DRM_MAJOR, "drm");
115 }
116 return 0;
117 }
118
119
DRM(stub_register)120 int DRM(stub_register)(const char *name, struct file_operations *fops,
121 drm_device_t *dev)
122 {
123 struct drm_stub_info *i = NULL;
124
125 DRM_DEBUG("\n");
126 if (register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops)))
127 i = (struct drm_stub_info *)inter_module_get("drm");
128
129 if (i) {
130 /* Already registered */
131 DRM(stub_info).info_register = i->info_register;
132 DRM(stub_info).info_unregister = i->info_unregister;
133 DRM_DEBUG("already registered\n");
134 } else if (DRM(stub_info).info_register != DRM(stub_getminor)) {
135 DRM(stub_info).info_register = DRM(stub_getminor);
136 DRM(stub_info).info_unregister = DRM(stub_putminor);
137 DRM_DEBUG("calling inter_module_register\n");
138 inter_module_register("drm", THIS_MODULE, &DRM(stub_info));
139 }
140 if (DRM(stub_info).info_register)
141 return DRM(stub_info).info_register(name, fops, dev);
142 return -1;
143 }
144
DRM(stub_unregister)145 int DRM(stub_unregister)(int minor)
146 {
147 DRM_DEBUG("%d\n", minor);
148 if (DRM(stub_info).info_unregister)
149 return DRM(stub_info).info_unregister(minor);
150 return -1;
151 }
152