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SDM845 SoC includes the Mobile Display Sub System (MDSS) which is a
top level wrapper consisting of Display Processing Unit (DPU) and
display peripheral modules such as Display Serial Interface (DSI)
and DisplayPort (DP).
MDSS functions essentially as a back-end composition engine. It blends
video and graphic images stored in the frame buffers and scans out the
composed image to a display sink (over DSI/DP).
The following diagram represents hardware blocks for a simple pipeline
(two planes are present on a given crtc which is connected to a DSI
connector):
MDSS
+---------------------------------+
| +-----------------------------+ |
| | DPU | |
| | +--------+ +--------+ | |
| | | SSPP | | SSPP | | |
| | +----+---+ +----+---+ | |
| | | | | |
| | +----v-----------v---+ | |
| | | Layer Mixer (LM) | | |
| | +--------------------+ | |
| | +--------------------+ | |
| | | PingPong (PP) | | |
| | +--------------------+ | |
| | +--------------------+ | |
| | | INTERFACE (VIDEO) | | |
| | +---+----------------+ | |
| +------|----------------------+ |
| | |
| +------|---------------------+ |
| | | DISPLAY PERIPHERALS | |
| | +---v-+ +-----+ | |
| | | DSI | | DP | | |
| | +-----+ +-----+ | |
| +----------------------------+ |
+---------------------------------+
The number of DPU sub-blocks (i.e. SSPPs, LMs, PP blocks and INTFs)
depends on SoC capabilities.
Overview of DPU sub-blocks:
---------------------------
* Source Surface Processor (SSPP):
Refers to any of hardware pipes like ViG, DMA etc. Only ViG pipes are
capable of performing format conversion, scaling and quality improvement
for source surfaces.
* Layer Mixer (LM):
Blend source surfaces together (in requested zorder)
* PingPong (PP):
This block controls frame done interrupt output, EOL and EOF generation,
overflow/underflow control.
* Display interface (INTF):
Timing generator and interface connecting the display peripherals.
DRM components mapping to DPU architecture:
------------------------------------------
PLANEs maps to SSPPs
CRTC maps to LMs
Encoder maps to PPs, INTFs
Data flow setup:
---------------
MDSS hardware can support various data flows (e.g.):
- Dual pipe: Output from two LMs combined to single display.
- Split display: Output from two LMs connected to two separate
interfaces.
The hardware capabilities determine the number of concurrent data paths
possible. Any control path (i.e. pipeline w/i DPU) can be routed to any
of the hardware data paths. A given control path can be triggered,
flushed and controlled independently.
Changes in v3:
- Move msm_media_info.h from uapi to dpu/ subdir
- Remove preclose callback dpu (it's handled in core)
- Fix kbuild warnings with parent_ops
- Remove unused functions from dpu_core_irq
- Rename mdss_phys to mdss
- Rename mdp_phys address space to mdp
- Drop _phys from vbif and regdma binding names
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rajesh Yadav <ryadav@codeaurora.org>
Signed-off-by: Sravanthi Kollukuduru <skolluku@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
[robclark minor rebase]
Signed-off-by: Rob Clark <robdclark@gmail.com>
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Jordan Crouse
Jeykumar Sankaran