1 /**************************************************************************
2 *
3 * Copyright © 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 * Thanks to krh and jcristau for the tips on
29 * going from fd to pci id via fstat and udev.
30 */
31
32
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #endif
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <xf86drm.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include <sys/stat.h>
43 #include <sys/types.h>
44 #ifdef MAJOR_IN_MKDEV
45 #include <sys/mkdev.h>
46 #endif
47 #ifdef MAJOR_IN_SYSMACROS
48 #include <sys/sysmacros.h>
49 #endif
50
51 #include "libdrm_macros.h"
52 #include "internal.h"
53
54 #define PATH_SIZE 512
55
56 static int
linux_name_from_sysfs(int fd,char ** out)57 linux_name_from_sysfs(int fd, char **out)
58 {
59 char path[PATH_SIZE+1] = ""; /* initialize to please valgrind */
60 char link[PATH_SIZE+1] = "";
61 struct stat buffer;
62 unsigned maj, min;
63 char* slash_name;
64 int ret;
65
66 /*
67 * Inside the sysfs directory for the device there is a symlink
68 * to the directory representing the driver module, that path
69 * happens to hold the name of the driver.
70 *
71 * So lets get the symlink for the drm device. Then read the link
72 * and filter out the last directory which happens to be the name
73 * of the driver, which we can use to load the correct interface.
74 *
75 * Thanks to Ray Strode of Plymouth for the code.
76 */
77
78 ret = fstat(fd, &buffer);
79 if (ret)
80 return -EINVAL;
81
82 if (!S_ISCHR(buffer.st_mode))
83 return -EINVAL;
84
85 maj = major(buffer.st_rdev);
86 min = minor(buffer.st_rdev);
87
88 snprintf(path, PATH_SIZE, "/sys/dev/char/%d:%d/device/driver", maj, min);
89
90 if (readlink(path, link, PATH_SIZE) < 0)
91 return -EINVAL;
92
93 /* link looks something like this: ../../../bus/pci/drivers/intel */
94 slash_name = strrchr(link, '/');
95 if (!slash_name)
96 return -EINVAL;
97
98 /* copy name and at the same time remove the slash */
99 *out = strdup(slash_name + 1);
100 return 0;
101 }
102
103 static int
linux_from_sysfs(int fd,struct kms_driver ** out)104 linux_from_sysfs(int fd, struct kms_driver **out)
105 {
106 char *name;
107 int ret;
108
109 ret = linux_name_from_sysfs(fd, &name);
110 if (ret)
111 return ret;
112
113 #ifdef HAVE_INTEL
114 if (!strcmp(name, "intel"))
115 ret = intel_create(fd, out);
116 else
117 #endif
118 #ifdef HAVE_VMWGFX
119 if (!strcmp(name, "vmwgfx"))
120 ret = vmwgfx_create(fd, out);
121 else
122 #endif
123 #ifdef HAVE_NOUVEAU
124 if (!strcmp(name, "nouveau"))
125 ret = nouveau_create(fd, out);
126 else
127 #endif
128 #ifdef HAVE_RADEON
129 if (!strcmp(name, "radeon"))
130 ret = radeon_create(fd, out);
131 else
132 #endif
133 #ifdef HAVE_EXYNOS
134 if (!strcmp(name, "exynos"))
135 ret = exynos_create(fd, out);
136 else
137 #endif
138 ret = -ENOSYS;
139
140 free(name);
141 return ret;
142 }
143
144 drm_private int
linux_create(int fd,struct kms_driver ** out)145 linux_create(int fd, struct kms_driver **out)
146 {
147 if (!dumb_create(fd, out))
148 return 0;
149
150 return linux_from_sysfs(fd, out);
151 }
152