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209264a857
Interactions between bridges, panels, MIPI-DSI host and the component framework are not trivial and can lead to probing issues when implementing a display driver. Let's document the various cases we need too consider, and the solution to support all the cases. Signed-off-by: Maxime Ripard <maxime@cerno.tech> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210910101218.1632297-3-maxime@cerno.tech
438 lines
11 KiB
ReStructuredText
438 lines
11 KiB
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=============================
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Mode Setting Helper Functions
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=============================
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The DRM subsystem aims for a strong separation between core code and helper
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libraries. Core code takes care of general setup and teardown and decoding
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userspace requests to kernel internal objects. Everything else is handled by a
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large set of helper libraries, which can be combined freely to pick and choose
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for each driver what fits, and avoid shared code where special behaviour is
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needed.
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This distinction between core code and helpers is especially strong in the
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modesetting code, where there's a shared userspace ABI for all drivers. This is
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in contrast to the render side, where pretty much everything (with very few
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exceptions) can be considered optional helper code.
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There are a few areas these helpers can grouped into:
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* Helpers to implement modesetting. The important ones here are the atomic
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helpers. Old drivers still often use the legacy CRTC helpers. They both share
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the same set of common helper vtables. For really simple drivers (anything
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that would have been a great fit in the deprecated fbdev subsystem) there's
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also the simple display pipe helpers.
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* There's a big pile of helpers for handling outputs. First the generic bridge
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helpers for handling encoder and transcoder IP blocks. Second the panel helpers
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for handling panel-related information and logic. Plus then a big set of
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helpers for the various sink standards (DisplayPort, HDMI, MIPI DSI). Finally
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there's also generic helpers for handling output probing, and for dealing with
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EDIDs.
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* The last group of helpers concerns itself with the frontend side of a display
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pipeline: Planes, handling rectangles for visibility checking and scissoring,
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flip queues and assorted bits.
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Modeset Helper Reference for Common Vtables
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===========================================
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.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
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:doc: overview
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.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
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:internal:
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.. _drm_atomic_helper:
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Atomic Modeset Helper Functions Reference
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=========================================
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Overview
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--------
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.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
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:doc: overview
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Implementing Asynchronous Atomic Commit
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---------------------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
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:doc: implementing nonblocking commit
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Helper Functions Reference
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--------------------------
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.. kernel-doc:: include/drm/drm_atomic_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
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:export:
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Atomic State Reset and Initialization
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-------------------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
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:doc: atomic state reset and initialization
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Atomic State Helper Reference
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-----------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
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:export:
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GEM Atomic Helper Reference
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---------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
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:doc: overview
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.. kernel-doc:: include/drm/drm_gem_atomic_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
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:export:
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Simple KMS Helper Reference
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===========================
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.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
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:doc: overview
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.. kernel-doc:: include/drm/drm_simple_kms_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
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:export:
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fbdev Helper Functions Reference
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================================
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.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
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:doc: fbdev helpers
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.. kernel-doc:: include/drm/drm_fb_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
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:export:
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format Helper Functions Reference
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=================================
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.. kernel-doc:: drivers/gpu/drm/drm_format_helper.c
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:export:
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Framebuffer CMA Helper Functions Reference
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==========================================
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.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
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:doc: framebuffer cma helper functions
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.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
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:export:
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Framebuffer GEM Helper Reference
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================================
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.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
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:doc: overview
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.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
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:export:
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.. _drm_bridges:
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Bridges
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=======
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Overview
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--------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
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:doc: overview
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Display Driver Integration
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--------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
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:doc: display driver integration
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Special Care with MIPI-DSI bridges
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----------------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
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:doc: special care dsi
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Bridge Operations
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-----------------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
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:doc: bridge operations
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Bridge Connector Helper
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-----------------------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
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:doc: overview
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Bridge Helper Reference
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-------------------------
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.. kernel-doc:: include/drm/drm_bridge.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
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:export:
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Bridge Connector Helper Reference
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---------------------------------
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.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
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:export:
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Panel-Bridge Helper Reference
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-----------------------------
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.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
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:export:
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.. _drm_panel_helper:
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Panel Helper Reference
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======================
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.. kernel-doc:: drivers/gpu/drm/drm_panel.c
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:doc: drm panel
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.. kernel-doc:: include/drm/drm_panel.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_panel.c
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:export:
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.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
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:export:
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Panel Self Refresh Helper Reference
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===================================
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.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
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:doc: overview
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.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
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:export:
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HDCP Helper Functions Reference
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===============================
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.. kernel-doc:: drivers/gpu/drm/drm_hdcp.c
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:export:
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Display Port Helper Functions Reference
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=======================================
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.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
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:doc: dp helpers
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.. kernel-doc:: include/drm/drm_dp_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
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:export:
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Display Port CEC Helper Functions Reference
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===========================================
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.. kernel-doc:: drivers/gpu/drm/drm_dp_cec.c
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:doc: dp cec helpers
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.. kernel-doc:: drivers/gpu/drm/drm_dp_cec.c
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:export:
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Display Port Dual Mode Adaptor Helper Functions Reference
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=========================================================
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.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
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:doc: dp dual mode helpers
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.. kernel-doc:: include/drm/drm_dp_dual_mode_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
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:export:
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Display Port MST Helpers
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========================
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Overview
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--------
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.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
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:doc: dp mst helper
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.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
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:doc: Branch device and port refcounting
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Functions Reference
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-------------------
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.. kernel-doc:: include/drm/drm_dp_mst_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
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:export:
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Topology Lifetime Internals
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---------------------------
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These functions aren't exported to drivers, but are documented here to help make
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the MST topology helpers easier to understand
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.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
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:functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
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drm_dp_mst_topology_put_mstb
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drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
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drm_dp_mst_topology_put_port
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drm_dp_mst_get_mstb_malloc drm_dp_mst_put_mstb_malloc
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MIPI DBI Helper Functions Reference
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===================================
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.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
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:doc: overview
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.. kernel-doc:: include/drm/drm_mipi_dbi.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
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:export:
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MIPI DSI Helper Functions Reference
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===================================
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.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
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:doc: dsi helpers
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.. kernel-doc:: include/drm/drm_mipi_dsi.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
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:export:
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Display Stream Compression Helper Functions Reference
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=====================================================
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.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
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:doc: dsc helpers
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.. kernel-doc:: include/drm/drm_dsc.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
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:export:
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Output Probing Helper Functions Reference
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=========================================
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.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
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:doc: output probing helper overview
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.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
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:export:
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EDID Helper Functions Reference
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===============================
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.. kernel-doc:: include/drm/drm_edid.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_edid.c
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:export:
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SCDC Helper Functions Reference
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===============================
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.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
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:doc: scdc helpers
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.. kernel-doc:: include/drm/drm_scdc_helper.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
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:export:
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HDMI Infoframes Helper Reference
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================================
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Strictly speaking this is not a DRM helper library but generally useable
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by any driver interfacing with HDMI outputs like v4l or alsa drivers.
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But it nicely fits into the overall topic of mode setting helper
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libraries and hence is also included here.
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.. kernel-doc:: include/linux/hdmi.h
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:internal:
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.. kernel-doc:: drivers/video/hdmi.c
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:export:
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Rectangle Utilities Reference
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=============================
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.. kernel-doc:: include/drm/drm_rect.h
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:doc: rect utils
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.. kernel-doc:: include/drm/drm_rect.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_rect.c
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:export:
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Flip-work Helper Reference
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==========================
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.. kernel-doc:: include/drm/drm_flip_work.h
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:doc: flip utils
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.. kernel-doc:: include/drm/drm_flip_work.h
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:internal:
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.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
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:export:
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Auxiliary Modeset Helpers
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=========================
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.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
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:doc: aux kms helpers
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.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
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:export:
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OF/DT Helpers
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=============
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.. kernel-doc:: drivers/gpu/drm/drm_of.c
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:doc: overview
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.. kernel-doc:: drivers/gpu/drm/drm_of.c
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:export:
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Legacy Plane Helper Reference
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=============================
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.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
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:doc: overview
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.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
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:export:
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Legacy CRTC/Modeset Helper Functions Reference
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==============================================
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.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
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:doc: overview
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.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
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:export:
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