1 | /* |
2 | * Generic System Framebuffers on x86 |
3 | * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify it |
6 | * under the terms of the GNU General Public License as published by the Free |
7 | * Software Foundation; either version 2 of the License, or (at your option) |
8 | * any later version. |
9 | */ |
10 | |
11 | /* |
12 | * Simple-Framebuffer support for x86 systems |
13 | * Create a platform-device for any available boot framebuffer. The |
14 | * simple-framebuffer platform device is already available on DT systems, so |
15 | * this module parses the global "screen_info" object and creates a suitable |
16 | * platform device compatible with the "simple-framebuffer" DT object. If |
17 | * the framebuffer is incompatible, we instead create a legacy |
18 | * "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and |
19 | * pass the screen_info as platform_data. This allows legacy drivers |
20 | * to pick these devices up without messing with simple-framebuffer drivers. |
21 | * The global "screen_info" is still valid at all times. |
22 | * |
23 | * If CONFIG_X86_SYSFB is not selected, we never register "simple-framebuffer" |
24 | * platform devices, but only use legacy framebuffer devices for |
25 | * backwards compatibility. |
26 | * |
27 | * TODO: We set the dev_id field of all platform-devices to 0. This allows |
28 | * other x86 OF/DT parsers to create such devices, too. However, they must |
29 | * start at offset 1 for this to work. |
30 | */ |
31 | |
32 | #include <linux/err.h> |
33 | #include <linux/init.h> |
34 | #include <linux/kernel.h> |
35 | #include <linux/mm.h> |
36 | #include <linux/platform_data/simplefb.h> |
37 | #include <linux/platform_device.h> |
38 | #include <linux/screen_info.h> |
39 | #include <asm/sysfb.h> |
40 | |
41 | static __init int sysfb_init(void) |
42 | { |
43 | struct screen_info *si = &screen_info; |
44 | struct simplefb_platform_data mode; |
45 | struct platform_device *pd; |
46 | const char *name; |
47 | bool compatible; |
48 | int ret; |
49 | |
50 | sysfb_apply_efi_quirks(); |
51 | |
52 | /* try to create a simple-framebuffer device */ |
53 | compatible = parse_mode(si, &mode); |
54 | if (compatible) { |
55 | ret = create_simplefb(si, &mode); |
56 | if (!ret) |
57 | return 0; |
58 | } |
59 | |
60 | /* if the FB is incompatible, create a legacy framebuffer device */ |
61 | if (si->orig_video_isVGA == VIDEO_TYPE_EFI) |
62 | name = "efi-framebuffer" ; |
63 | else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB) |
64 | name = "vesa-framebuffer" ; |
65 | else |
66 | name = "platform-framebuffer" ; |
67 | |
68 | pd = platform_device_register_resndata(NULL, name, 0, |
69 | NULL, 0, si, sizeof(*si)); |
70 | return PTR_ERR_OR_ZERO(pd); |
71 | } |
72 | |
73 | /* must execute after PCI subsystem for EFI quirks */ |
74 | device_initcall(sysfb_init); |
75 | |