1 /*
2 * linux/drivers/video/fb_cmdline.c
3 *
4 * Copyright (C) 2014 Intel Corp
5 * Copyright (C) 1994 Martin Schaller
6 *
7 * 2001 - Documented with DocBook
8 * - Brad Douglas <brad@neruo.com>
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file COPYING in the main directory of this archive
12 * for more details.
13 *
14 * Authors:
15 * Vetter <danie.vetter@ffwll.ch>
16 */
17 #include <linux/init.h>
18 #include <linux/fb.h>
19
20 static char *video_options[FB_MAX] __read_mostly;
21 static int ofonly __read_mostly;
22
23 const char *fb_mode_option;
24 EXPORT_SYMBOL_GPL(fb_mode_option);
25
26 /**
27 * fb_get_options - get kernel boot parameters
28 * @name: framebuffer name as it would appear in
29 * the boot parameter line
30 * (video=<name>:<options>)
31 * @option: the option will be stored here
32 *
33 * NOTE: Needed to maintain backwards compatibility
34 */
35 int fb_get_options(const char *name, char **option)
36 {
37 char *opt, *options = NULL;
38 int retval = 0;
39 int name_len = strlen(name), i;
40
41 if (name_len && ofonly && strncmp(name, "offb", 4))
42 retval = 1;
43
44 if (name_len && !retval) {
45 for (i = 0; i < FB_MAX; i++) {
46 if (video_options[i] == NULL)
47 continue;
48 if (!video_options[i][0])
49 continue;
50 opt = video_options[i];
51 if (!strncmp(name, opt, name_len) &&
52 opt[name_len] == ':')
53 options = opt + name_len + 1;
54 }
55 }
56 /* No match, pass global option */
57 if (!options && option && fb_mode_option)
58 options = kstrdup(fb_mode_option, GFP_KERNEL);
59 if (options && !strncmp(options, "off", 3))
60 retval = 1;
61
62 if (option)
63 *option = options;
64
65 return retval;
66 }
67 EXPORT_SYMBOL(fb_get_options);
68
69 /**
70 * video_setup - process command line options
71 * @options: string of options
72 *
73 * Process command line options for frame buffer subsystem.
74 *
75 * NOTE: This function is a __setup and __init function.
76 * It only stores the options. Drivers have to call
77 * fb_get_options() as necessary.
78 */
79 static int __init video_setup(char *options)
80 {
81 if (!options || !*options)
82 goto out;
83
84 if (!strncmp(options, "ofonly", 6)) {
85 ofonly = 1;
86 goto out;
87 }
88
89 if (strchr(options, ':')) {
90 /* named */
91 int i;
92
93 for (i = 0; i < FB_MAX; i++) {
94 if (video_options[i] == NULL) {
95 video_options[i] = options;
96 break;
97 }
98 }
99 } else {
100 /* global */
101 fb_mode_option = options;
102 }
103
104 out:
105 return 1;
106 }
107 __setup("video=", video_setup);