xref: /OK3568_Linux_fs/kernel/drivers/gpu/drm/sti/NOTES (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun1. stiH display hardware IP
2*4882a593Smuzhiyun---------------------------
3*4882a593SmuzhiyunThe STMicroelectronics stiH SoCs use a common chain of HW display IP blocks:
4*4882a593Smuzhiyun- The High Quality Video Display Processor (HQVDP) gets video frames from a
5*4882a593Smuzhiyun  video decoder and does high quality video processing, including scaling.
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun- The Compositor is a multiplane, dual-mixer (Main & Aux) digital processor. It
8*4882a593Smuzhiyun  has several inputs:
9*4882a593Smuzhiyun  - The graphics planes are internally processed by the Generic Display
10*4882a593Smuzhiyun    Pipeline (GDP).
11*4882a593Smuzhiyun  - The video plug (VID) connects to the HQVDP output.
12*4882a593Smuzhiyun  - The cursor handles ... a cursor.
13*4882a593Smuzhiyun- The TV OUT pre-formats (convert, clip, round) the compositor output data
14*4882a593Smuzhiyun- The HDMI / DVO / HD Analog / SD analog IP builds the video signals
15*4882a593Smuzhiyun  - DVO (Digital Video Output) handles a 24bits parallel signal
16*4882a593Smuzhiyun  - The HD analog signal is typically driven by a YCbCr cable, supporting up to
17*4882a593Smuzhiyun    1080i mode.
18*4882a593Smuzhiyun  - The SD analog signal is typically used for legacy TV
19*4882a593Smuzhiyun- The VTG (Video Timing Generators) build Vsync signals used by the other HW IP
20*4882a593SmuzhiyunNote that some stiH drivers support only a subset of thee HW IP.
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun                  .-------------.   .-----------.   .-----------.
23*4882a593SmuzhiyunGPU >-------------+GDP     Main |   |           +---+    HDMI   +--> HDMI
24*4882a593SmuzhiyunGPU >-------------+GDP     mixer+---+           |   :===========:
25*4882a593SmuzhiyunGPU >-------------+Cursor       |   |           +---+    DVO    +--> 24b//
26*4882a593Smuzhiyun        -------   |  COMPOSITOR |   |  TV OUT   |   :===========:
27*4882a593Smuzhiyun       |       |  |             |   |           +---+ HD analog +--> YCbCr
28*4882a593SmuzhiyunVid >--+ HQVDP +--+VID     Aux  +---+           |   :===========:
29*4882a593Smuzhiyundec    |       |  |        mixer|   |           +---+ SD analog +--> CVBS
30*4882a593Smuzhiyun       '-------'  '-------------'   '-----------'   '-----------'
31*4882a593Smuzhiyun                   .-----------.
32*4882a593Smuzhiyun                   |       main+--> Vsync
33*4882a593Smuzhiyun                   | VTG       |
34*4882a593Smuzhiyun                   |        aux+--> Vsync
35*4882a593Smuzhiyun                   '-----------'
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun2. DRM / HW mapping
38*4882a593Smuzhiyun-------------------
39*4882a593SmuzhiyunThese IP are mapped to the DRM objects as following:
40*4882a593Smuzhiyun- The CRTCs are mapped to the Compositor Main and Aux Mixers
41*4882a593Smuzhiyun- The Framebuffers and planes are mapped to the Compositor GDP (non video
42*4882a593Smuzhiyun  buffers) and to HQVDP+VID (video buffers)
43*4882a593Smuzhiyun- The Cursor is mapped to the Compositor Cursor
44*4882a593Smuzhiyun- The Encoders are mapped to the TVOut
45*4882a593Smuzhiyun- The Bridges/Connectors are mapped to the HDMI / DVO / HD Analog / SD analog
46*4882a593Smuzhiyun
47*4882a593SmuzhiyunFB & planes         Cursor      CRTC     Encoders    Bridges/Connectors
48*4882a593Smuzhiyun   |                   |          |         |                       |
49*4882a593Smuzhiyun   |                   |          |         |                       |
50*4882a593Smuzhiyun   |              .-------------. | .-----------.   .-----------.   |
51*4882a593Smuzhiyun   +------------> |GDP |   Main | | |       +-> |   |    HDMI   | <-+
52*4882a593Smuzhiyun   +------------> |GDP v   mixer|<+ |       |   |   :===========:   |
53*4882a593Smuzhiyun   |              |Cursor       | | |       +-> |   |    DVO    | <-+
54*4882a593Smuzhiyun   |    -------   |  COMPOSITOR | | |TV OUT |   |   :===========:   |
55*4882a593Smuzhiyun   |   |       |  |             | | |       +-> |   | HD analog | <-+
56*4882a593Smuzhiyun   +-> | HQVDP |  |VID     Aux  |<+ |       |   |   :===========:   |
57*4882a593Smuzhiyun       |       |  |        mixer|   |       +-> |   | SD analog | <-+
58*4882a593Smuzhiyun       '-------'  '-------------'   '-----------'   '-----------'
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