drivers/video/fbdev/core/fb_cmdline.c

   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  *    Daniel Vetter <daniel.vetter@ffwll.ch>
  16  */
  17
  18 #include <linux/export.h>
  19 #include <linux/fb.h>
  20 #include <linux/string.h>
  21
  22 #include <video/cmdline.h>
  23
  24 /**
  25  * fb_get_options - get kernel boot parameters
  26  * @name:   framebuffer name as it would appear in
  27  *          the boot parameter line
  28  *          (video=<name>:<options>)
  29  * @option: the option will be stored here
  30  *
  31  * The caller owns the string returned in @option and is
  32  * responsible for releasing the memory.
  33  *
  34  * NOTE: Needed to maintain backwards compatibility
  35  */
  36 int fb_get_options(const char *name, char **option)
  37 {
  38         const char *options = NULL;
  39         bool is_of = false;
  40         bool enabled;
  41
  42         if (name)
  43                 is_of = strncmp(name, "offb", 4);
  44
  45         enabled = __video_get_options(name, &options, is_of);
  46
  47         if (options) {
  48                 if (!strncmp(options, "off", 3))
  49                         enabled = false;
  50         }
  51
  52         if (option) {
  53                 if (options)
  54                         *option = kstrdup(options, GFP_KERNEL);
  55                 else
  56                         *option = NULL;
  57         }
  58
  59         return enabled ? 0 : 1; // 0 on success, 1 otherwise
  60 }
  61 EXPORT_SYMBOL(fb_get_options);