linux-zen-server/drivers/video/fbdev/core/fb_cmdline.c

108 lines
2.4 KiB
C

/*
* linux/drivers/video/fb_cmdline.c
*
* Copyright (C) 2014 Intel Corp
* Copyright (C) 1994 Martin Schaller
*
* 2001 - Documented with DocBook
* - Brad Douglas <brad@neruo.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*
* Authors:
* Vetter <danie.vetter@ffwll.ch>
*/
#include <linux/init.h>
#include <linux/fb.h>
static char *video_options[FB_MAX] __read_mostly;
static int ofonly __read_mostly;
const char *fb_mode_option;
EXPORT_SYMBOL_GPL(fb_mode_option);
/**
* fb_get_options - get kernel boot parameters
* @name: framebuffer name as it would appear in
* the boot parameter line
* (video=<name>:<options>)
* @option: the option will be stored here
*
* NOTE: Needed to maintain backwards compatibility
*/
int fb_get_options(const char *name, char **option)
{
char *opt, *options = NULL;
int retval = 0;
int name_len = strlen(name), i;
if (name_len && ofonly && strncmp(name, "offb", 4))
retval = 1;
if (name_len && !retval) {
for (i = 0; i < FB_MAX; i++) {
if (video_options[i] == NULL)
continue;
if (!video_options[i][0])
continue;
opt = video_options[i];
if (!strncmp(name, opt, name_len) &&
opt[name_len] == ':')
options = opt + name_len + 1;
}
}
/* No match, pass global option */
if (!options && option && fb_mode_option)
options = kstrdup(fb_mode_option, GFP_KERNEL);
if (options && !strncmp(options, "off", 3))
retval = 1;
if (option)
*option = options;
return retval;
}
EXPORT_SYMBOL(fb_get_options);
/**
* video_setup - process command line options
* @options: string of options
*
* Process command line options for frame buffer subsystem.
*
* NOTE: This function is a __setup and __init function.
* It only stores the options. Drivers have to call
* fb_get_options() as necessary.
*/
static int __init video_setup(char *options)
{
if (!options || !*options)
goto out;
if (!strncmp(options, "ofonly", 6)) {
ofonly = 1;
goto out;
}
if (strchr(options, ':')) {
/* named */
int i;
for (i = 0; i < FB_MAX; i++) {
if (video_options[i] == NULL) {
video_options[i] = options;
break;
}
}
} else {
/* global */
fb_mode_option = options;
}
out:
return 1;
}
__setup("video=", video_setup);