diff options
author | Jonathan Corbet <corbet@lwn.net> | 2016-08-20 15:17:32 -0400 |
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committer | Jonathan Corbet <corbet@lwn.net> | 2016-08-22 16:42:08 -0400 |
commit | dcec3c8c9aea9e779c59f420465381c0f3322913 (patch) | |
tree | f8752c216e37a44941af6a16fda595c0fa4dde0d /Documentation/driver-api/frame-buffer.rst | |
parent | 47cb398dd75a9faa89d0617b55d4cf537935b731 (diff) |
docs: split up the driver book
We don't need to keep it as a single large file anymore; split it up so
that it is easier to manage and the individual sections can be read
directly as plain files.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/driver-api/frame-buffer.rst')
-rw-r--r-- | Documentation/driver-api/frame-buffer.rst | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/driver-api/frame-buffer.rst b/Documentation/driver-api/frame-buffer.rst new file mode 100644 index 000000000000..9dd3060f027d --- /dev/null +++ b/Documentation/driver-api/frame-buffer.rst | |||
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1 | Frame Buffer Library | ||
2 | ==================== | ||
3 | |||
4 | The frame buffer drivers depend heavily on four data structures. These | ||
5 | structures are declared in include/linux/fb.h. They are fb_info, | ||
6 | fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs. The last | ||
7 | three can be made available to and from userland. | ||
8 | |||
9 | fb_info defines the current state of a particular video card. Inside | ||
10 | fb_info, there exists a fb_ops structure which is a collection of | ||
11 | needed functions to make fbdev and fbcon work. fb_info is only visible | ||
12 | to the kernel. | ||
13 | |||
14 | fb_var_screeninfo is used to describe the features of a video card | ||
15 | that are user defined. With fb_var_screeninfo, things such as depth | ||
16 | and the resolution may be defined. | ||
17 | |||
18 | The next structure is fb_fix_screeninfo. This defines the properties | ||
19 | of a card that are created when a mode is set and can't be changed | ||
20 | otherwise. A good example of this is the start of the frame buffer | ||
21 | memory. This "locks" the address of the frame buffer memory, so that it | ||
22 | cannot be changed or moved. | ||
23 | |||
24 | The last structure is fb_monospecs. In the old API, there was little | ||
25 | importance for fb_monospecs. This allowed for forbidden things such as | ||
26 | setting a mode of 800x600 on a fix frequency monitor. With the new API, | ||
27 | fb_monospecs prevents such things, and if used correctly, can prevent a | ||
28 | monitor from being cooked. fb_monospecs will not be useful until | ||
29 | kernels 2.5.x. | ||
30 | |||
31 | Frame Buffer Memory | ||
32 | ------------------- | ||
33 | |||
34 | .. kernel-doc:: drivers/video/fbdev/core/fbmem.c | ||
35 | :export: | ||
36 | |||
37 | Frame Buffer Colormap | ||
38 | --------------------- | ||
39 | |||
40 | .. kernel-doc:: drivers/video/fbdev/core/fbcmap.c | ||
41 | :export: | ||
42 | |||
43 | Frame Buffer Video Mode Database | ||
44 | -------------------------------- | ||
45 | |||
46 | .. kernel-doc:: drivers/video/fbdev/core/modedb.c | ||
47 | :internal: | ||
48 | |||
49 | .. kernel-doc:: drivers/video/fbdev/core/modedb.c | ||
50 | :export: | ||
51 | |||
52 | Frame Buffer Macintosh Video Mode Database | ||
53 | ------------------------------------------ | ||
54 | |||
55 | .. kernel-doc:: drivers/video/fbdev/macmodes.c | ||
56 | :export: | ||
57 | |||
58 | Frame Buffer Fonts | ||
59 | ------------------ | ||
60 | |||
61 | Refer to the file lib/fonts/fonts.c for more information. | ||
62 | |||