projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 93604a5a TZ |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* | |
| 3 | * Based on the fbdev code in drivers/video/fbdev/core/fb_cmdline: | |
| 4 | * | |
| 5 | * Copyright (C) 2014 Intel Corp | |
| 6 | * Copyright (C) 1994 Martin Schaller | |
| 7 | * | |
| 8 | * 2001 - Documented with DocBook | |
| 9 | * - Brad Douglas <brad@neruo.com> | |
| 10 | * | |
| 11 | * This file is subject to the terms and conditions of the GNU General Public | |
| 12 | * License. See the file COPYING in the main directory of this archive | |
| 13 | * for more details. | |
| 14 | * | |
| 15 | * Authors: | |
| 16 | * Daniel Vetter <daniel.vetter@ffwll.ch> | |
| 17 | */ | |
| 18 | ||
| 19 | #include <linux/fb.h> /* for FB_MAX */ | |
| 20 | #include <linux/init.h> | |
| 21 | ||
| 22 | #include <video/cmdline.h> | |
| 23 | ||
| 24 | /* | |
| 25 | * FB_MAX is the maximum number of framebuffer devices and also | |
| 26 | * the maximum number of video= parameters. Although not directly | |
| 27 | * related to each other, it makes sense to keep it that way. | |
| 28 | */ | |
| 29 | static const char *video_options[FB_MAX] __read_mostly; | |
| 30 | static const char *video_option __read_mostly; | |
| 31 | static int video_of_only __read_mostly; | |
| 32 | ||
| 33 | static const char *__video_get_option_string(const char *name) | |
| 34 | { | |
| 35 | const char *options = NULL; | |
| 36 | size_t name_len = 0; | |
| 37 | ||
| 38 | if (name) | |
| 39 | name_len = strlen(name); | |
| 40 | ||
| 41 | if (name_len) { | |
| 42 | unsigned int i; | |
| 43 | const char *opt; | |
| 44 | ||
| 45 | for (i = 0; i < ARRAY_SIZE(video_options); ++i) { | |
| 46 | if (!video_options[i]) | |
| 47 | continue; | |
| 48 | if (video_options[i][0] == '\0') | |
| 49 | continue; | |
| 50 | opt = video_options[i]; | |
| 51 | if (!strncmp(opt, name, name_len) && opt[name_len] == ':') | |
| 52 | options = opt + name_len + 1; | |
| 53 | } | |
| 54 | } | |
| 55 | ||
| 56 | /* No match, return global options */ | |
| 57 | if (!options) | |
| 58 | options = video_option; | |
| 59 | ||
| 60 | return options; | |
| 61 | } | |
| 62 | ||
| 63 | /** | |
| 64 | * video_get_options - get kernel boot parameters | |
| 65 | * @name: name of the output as it would appear in the boot parameter | |
| 66 | * line (video=<name>:<options>) | |
| 67 | * | |
| 68 | * Looks up the video= options for the given name. Names are connector | |
| 69 | * names with DRM, or driver names with fbdev. If no video option for | |
| 70 | * the name has been specified, the function returns the global video= | |
| 71 | * setting. A @name of NULL always returns the global video setting. | |
| 72 | * | |
| 73 | * Returns: | |
| 74 | * The string of video options for the given name, or NULL if no video | |
| 75 | * option has been specified. | |
| 76 | */ | |
| 77 | const char *video_get_options(const char *name) | |
| 78 | { | |
| 79 | return __video_get_option_string(name); | |
| 80 | } | |
| 81 | EXPORT_SYMBOL(video_get_options); | |
| 82 | ||
| 83 | bool __video_get_options(const char *name, const char **options, bool is_of) | |
| 84 | { | |
| 85 | bool enabled = true; | |
| 86 | const char *opt = NULL; | |
| 87 | ||
| 88 | if (video_of_only && !is_of) | |
| 89 | enabled = false; | |
| 90 | ||
| 91 | opt = __video_get_option_string(name); | |
| 92 | ||
| 93 | if (options) | |
| 94 | *options = opt; | |
| 95 | ||
| 96 | return enabled; | |
| 97 | } | |
| 98 | EXPORT_SYMBOL(__video_get_options); | |
| 99 | ||
| 100 | /* | |
| 101 | * Process command line options for video adapters. This function is | |
| 102 | * a __setup and __init function. It only stores the options. Drivers | |
| 103 | * have to call video_get_options() as necessary. | |
| 104 | */ | |
| 105 | static int __init video_setup(char *options) | |
| 106 | { | |
| 107 | if (!options || !*options) | |
| 108 | goto out; | |
| 109 | ||
| 110 | if (!strncmp(options, "ofonly", 6)) { | |
| 111 | video_of_only = true; | |
| 112 | goto out; | |
| 113 | } | |
| 114 | ||
| 115 | if (strchr(options, ':')) { | |
| 116 | /* named */ | |
| 117 | size_t i; | |
| 118 | ||
| 119 | for (i = 0; i < ARRAY_SIZE(video_options); i++) { | |
| 120 | if (!video_options[i]) { | |
| 121 | video_options[i] = options; | |
| 122 | break; | |
| 123 | } | |
| 124 | } | |
| 125 | } else { | |
| 126 | /* global */ | |
| 127 | video_option = options; | |
| 128 | } | |
| 129 | ||
| 130 | out: | |
| 131 | return 1; | |
| 132 | } | |
| 133 | __setup("video=", video_setup); |