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 * Returns zero. 80 * 81 */ 82 static 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