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
20static char *video_options[FB_MAX] __read_mostly;
21static int ofonly __read_mostly;
22
23const char *fb_mode_option;
24EXPORT_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 */
35int 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}
67EXPORT_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 *	Returns zero.
80 *
81 */
82static int __init video_setup(char *options)
83{
84	int i, global = 0;
85
86	if (!options || !*options)
87		global = 1;
88
89	if (!global && !strncmp(options, "ofonly", 6)) {
90		ofonly = 1;
91		global = 1;
92	}
93
94	if (!global && !strchr(options, ':')) {
95		fb_mode_option = options;
96		global = 1;
97	}
98
99	if (!global) {
100		for (i = 0; i < FB_MAX; i++) {
101			if (video_options[i] == NULL) {
102				video_options[i] = options;
103				break;
104			}
105		}
106	}
107
108	return 1;
109}
110__setup("video=", video_setup);
111