xref: /kernel/linux/linux-6.6/drivers/gpu/drm/sti/NOTES (revision 62306a36)
162306a36Sopenharmony_ci1. stiH display hardware IP
262306a36Sopenharmony_ci---------------------------
362306a36Sopenharmony_ciThe STMicroelectronics stiH SoCs use a common chain of HW display IP blocks:
462306a36Sopenharmony_ci- The High Quality Video Display Processor (HQVDP) gets video frames from a
562306a36Sopenharmony_ci  video decoder and does high quality video processing, including scaling.
662306a36Sopenharmony_ci
762306a36Sopenharmony_ci- The Compositor is a multiplane, dual-mixer (Main & Aux) digital processor. It
862306a36Sopenharmony_ci  has several inputs:
962306a36Sopenharmony_ci  - The graphics planes are internally processed by the Generic Display
1062306a36Sopenharmony_ci    Pipeline (GDP).
1162306a36Sopenharmony_ci  - The video plug (VID) connects to the HQVDP output.
1262306a36Sopenharmony_ci  - The cursor handles ... a cursor.
1362306a36Sopenharmony_ci- The TV OUT pre-formats (convert, clip, round) the compositor output data
1462306a36Sopenharmony_ci- The HDMI / DVO / HD Analog / SD analog IP builds the video signals
1562306a36Sopenharmony_ci  - DVO (Digital Video Output) handles a 24bits parallel signal
1662306a36Sopenharmony_ci  - The HD analog signal is typically driven by a YCbCr cable, supporting up to
1762306a36Sopenharmony_ci    1080i mode.
1862306a36Sopenharmony_ci  - The SD analog signal is typically used for legacy TV
1962306a36Sopenharmony_ci- The VTG (Video Timing Generators) build Vsync signals used by the other HW IP
2062306a36Sopenharmony_ciNote that some stiH drivers support only a subset of thee HW IP.
2162306a36Sopenharmony_ci
2262306a36Sopenharmony_ci                  .-------------.   .-----------.   .-----------.
2362306a36Sopenharmony_ciGPU >-------------+GDP     Main |   |           +---+    HDMI   +--> HDMI
2462306a36Sopenharmony_ciGPU >-------------+GDP     mixer+---+           |   :===========:
2562306a36Sopenharmony_ciGPU >-------------+Cursor       |   |           +---+    DVO    +--> 24b//
2662306a36Sopenharmony_ci        -------   |  COMPOSITOR |   |  TV OUT   |   :===========:
2762306a36Sopenharmony_ci       |       |  |             |   |           +---+ HD analog +--> YCbCr
2862306a36Sopenharmony_ciVid >--+ HQVDP +--+VID     Aux  +---+           |   :===========:
2962306a36Sopenharmony_cidec    |       |  |        mixer|   |           +---+ SD analog +--> CVBS
3062306a36Sopenharmony_ci       '-------'  '-------------'   '-----------'   '-----------'
3162306a36Sopenharmony_ci                   .-----------.
3262306a36Sopenharmony_ci                   |       main+--> Vsync
3362306a36Sopenharmony_ci                   | VTG       |
3462306a36Sopenharmony_ci                   |        aux+--> Vsync
3562306a36Sopenharmony_ci                   '-----------'
3662306a36Sopenharmony_ci
3762306a36Sopenharmony_ci2. DRM / HW mapping
3862306a36Sopenharmony_ci-------------------
3962306a36Sopenharmony_ciThese IP are mapped to the DRM objects as following:
4062306a36Sopenharmony_ci- The CRTCs are mapped to the Compositor Main and Aux Mixers
4162306a36Sopenharmony_ci- The Framebuffers and planes are mapped to the Compositor GDP (non video
4262306a36Sopenharmony_ci  buffers) and to HQVDP+VID (video buffers)
4362306a36Sopenharmony_ci- The Cursor is mapped to the Compositor Cursor
4462306a36Sopenharmony_ci- The Encoders are mapped to the TVOut
4562306a36Sopenharmony_ci- The Bridges/Connectors are mapped to the HDMI / DVO / HD Analog / SD analog
4662306a36Sopenharmony_ci
4762306a36Sopenharmony_ciFB & planes         Cursor      CRTC     Encoders    Bridges/Connectors
4862306a36Sopenharmony_ci   |                   |          |         |                       |
4962306a36Sopenharmony_ci   |                   |          |         |                       |
5062306a36Sopenharmony_ci   |              .-------------. | .-----------.   .-----------.   |
5162306a36Sopenharmony_ci   +------------> |GDP |   Main | | |       +-> |   |    HDMI   | <-+
5262306a36Sopenharmony_ci   +------------> |GDP v   mixer|<+ |       |   |   :===========:   |
5362306a36Sopenharmony_ci   |              |Cursor       | | |       +-> |   |    DVO    | <-+
5462306a36Sopenharmony_ci   |    -------   |  COMPOSITOR | | |TV OUT |   |   :===========:   |
5562306a36Sopenharmony_ci   |   |       |  |             | | |       +-> |   | HD analog | <-+
5662306a36Sopenharmony_ci   +-> | HQVDP |  |VID     Aux  |<+ |       |   |   :===========:   |
5762306a36Sopenharmony_ci       |       |  |        mixer|   |       +-> |   | SD analog | <-+
5862306a36Sopenharmony_ci       '-------'  '-------------'   '-----------'   '-----------'
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