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