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
41static __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 */
74device_initcall(sysfb_init);
75