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Commit | Line | Data |
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af60313d MH |
1 | |
2 | VPBE V4L2 driver design | |
3 | ====================================================================== | |
4 | ||
5 | File partitioning | |
6 | ----------------- | |
7 | V4L2 display device driver | |
8 | drivers/media/video/davinci/vpbe_display.c | |
9 | drivers/media/video/davinci/vpbe_display.h | |
10 | ||
11 | VPBE display controller | |
12 | drivers/media/video/davinci/vpbe.c | |
13 | drivers/media/video/davinci/vpbe.h | |
14 | ||
15 | VPBE venc sub device driver | |
16 | drivers/media/video/davinci/vpbe_venc.c | |
17 | drivers/media/video/davinci/vpbe_venc.h | |
18 | drivers/media/video/davinci/vpbe_venc_regs.h | |
19 | ||
20 | VPBE osd driver | |
21 | drivers/media/video/davinci/vpbe_osd.c | |
22 | drivers/media/video/davinci/vpbe_osd.h | |
23 | drivers/media/video/davinci/vpbe_osd_regs.h | |
24 | ||
25 | Functional partitioning | |
26 | ----------------------- | |
27 | ||
28 | Consists of the following (in the same order as the list under file | |
29 | partitioning):- | |
30 | ||
31 | 1. V4L2 display driver | |
32 | Implements creation of video2 and video3 device nodes and | |
33 | provides v4l2 device interface to manage VID0 and VID1 layers. | |
34 | ||
35 | 2. Display controller | |
36 | Loads up VENC, OSD and external encoders such as ths8200. It provides | |
37 | a set of API calls to V4L2 drivers to set the output/standards | |
38 | in the VENC or external sub devices. It also provides | |
39 | a device object to access the services from OSD subdevice | |
40 | using sub device ops. The connection of external encoders to VENC LCD | |
41 | controller port is done at init time based on default output and standard | |
42 | selection or at run time when application change the output through | |
43 | V4L2 IOCTLs. | |
44 | ||
45 | When connected to an external encoder, vpbe controller is also responsible | |
46 | for setting up the interface between VENC and external encoders based on | |
47 | board specific settings (specified in board-xxx-evm.c). This allows | |
48 | interfacing external encoders such as ths8200. The setup_if_config() | |
49 | is implemented for this as well as configure_venc() (part of the next patch) | |
50 | API to set timings in VENC for a specific display resolution. As of this | |
51 | patch series, the interconnection and enabling and setting of the external | |
52 | encoders is not present, and would be a part of the next patch series. | |
53 | ||
54 | 3. VENC subdevice module | |
55 | Responsible for setting outputs provided through internal DACs and also | |
56 | setting timings at LCD controller port when external encoders are connected | |
57 | at the port or LCD panel timings required. When external encoder/LCD panel | |
58 | is connected, the timings for a specific standard/preset is retrieved from | |
59 | the board specific table and the values are used to set the timings in | |
60 | venc using non-standard timing mode. | |
61 | ||
62 | Support LCD Panel displays using the VENC. For example to support a Logic | |
63 | PD display, it requires setting up the LCD controller port with a set of | |
64 | timings for the resolution supported and setting the dot clock. So we could | |
65 | add the available outputs as a board specific entry (i.e add the "LogicPD" | |
66 | output name to board-xxx-evm.c). A table of timings for various LCDs | |
67 | supported can be maintained in the board specific setup file to support | |
68 | various LCD displays.As of this patch a basic driver is present, and this | |
69 | support for external encoders and displays forms a part of the next | |
70 | patch series. | |
71 | ||
72 | 4. OSD module | |
73 | OSD module implements all OSD layer management and hardware specific | |
74 | features. The VPBE module interacts with the OSD for enabling and | |
75 | disabling appropriate features of the OSD. | |
76 | ||
77 | Current status:- | |
78 | ||
79 | A fully functional working version of the V4L2 driver is available. This | |
80 | driver has been tested with NTSC and PAL standards and buffer streaming. | |
81 | ||
82 | Following are TBDs. | |
83 | ||
84 | vpbe display controller | |
85 | - Add support for external encoders. | |
86 | - add support for selecting external encoder as default at probe time. | |
87 | ||
88 | vpbe venc sub device | |
89 | - add timings for supporting ths8200 | |
90 | - add support for LogicPD LCD. | |
91 | ||
92 | FB drivers | |
93 | - Add support for fbdev drivers.- Ready and part of subsequent patches. |