1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Generic System Framebuffers
* Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
*/
/*
* Simple-Framebuffer support
* Create a platform-device for any available boot framebuffer. The
* simple-framebuffer platform device is already available on DT systems, so
* this module parses the global "screen_info" object and creates a suitable
* platform device compatible with the "simple-framebuffer" DT object. If
* the framebuffer is incompatible, we instead create a legacy
* "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and
* pass the screen_info as platform_data. This allows legacy drivers
* to pick these devices up without messing with simple-framebuffer drivers.
* The global "screen_info" is still valid at all times.
*
* If CONFIG_SYSFB_SIMPLEFB is not selected, never register "simple-framebuffer"
* platform devices, but only use legacy framebuffer devices for
* backwards compatibility.
*
* TODO: We set the dev_id field of all platform-devices to 0. This allows
* other OF/DT parsers to create such devices, too. However, they must
* start at offset 1 for this to work.
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>
#include <linux/sysfb.h>
static struct platform_device *pd;
static DEFINE_MUTEX(disable_lock);
static bool disabled;
static bool sysfb_unregister(void)
{
if (IS_ERR_OR_NULL(pd))
return false;
platform_device_unregister(pd);
pd = NULL;
return true;
}
/**
* sysfb_disable() - disable the Generic System Framebuffers support
*
* This disables the registration of system framebuffer devices that match the
* generic drivers that make use of the system framebuffer set up by firmware.
*
* It also unregisters a device if this was already registered by sysfb_init().
*
* Context: The function can sleep. A @disable_lock mutex is acquired to serialize
* against sysfb_init(), that registers a system framebuffer device.
*/
void sysfb_disable(void)
{
mutex_lock(&disable_lock);
sysfb_unregister();
disabled = true;
mutex_unlock(&disable_lock);
}
EXPORT_SYMBOL_GPL(sysfb_disable);
static __init int sysfb_init(void)
{
struct screen_info *si = &screen_info;
struct simplefb_platform_data mode;
const char *name;
bool compatible;
int ret = 0;
mutex_lock(&disable_lock);
if (disabled)
goto unlock_mutex;
sysfb_apply_efi_quirks();
/* try to create a simple-framebuffer device */
compatible = sysfb_parse_mode(si, &mode);
if (compatible) {
pd = sysfb_create_simplefb(si, &mode);
if (!IS_ERR(pd))
goto unlock_mutex;
}
/* if the FB is incompatible, create a legacy framebuffer device */
if (si->orig_video_isVGA == VIDEO_TYPE_EFI)
name = "efi-framebuffer";
else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB)
name = "vesa-framebuffer";
else if (si->orig_video_isVGA == VIDEO_TYPE_VGAC)
name = "vga-framebuffer";
else if (si->orig_video_isVGA == VIDEO_TYPE_EGAC)
name = "ega-framebuffer";
else
name = "platform-framebuffer";
pd = platform_device_alloc(name, 0);
if (!pd) {
ret = -ENOMEM;
goto unlock_mutex;
}
sysfb_set_efifb_fwnode(pd);
ret = platform_device_add_data(pd, si, sizeof(*si));
if (ret)
goto err;
ret = platform_device_add(pd);
if (ret)
goto err;
goto unlock_mutex;
err:
platform_device_put(pd);
unlock_mutex:
mutex_unlock(&disable_lock);
return ret;
}
/* must execute after PCI subsystem for EFI quirks */
subsys_initcall_sync(sysfb_init);
|
