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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-11 18:12:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-11 18:12:22 -0700
commit6b25e21fa6f26d0f0d45f161d169029411c84286 (patch)
treefdff805ecd81ec46951f49577efe450ddb7d060a /Documentation/gpu/drm-kms-helpers.rst
parenta379f71a30dddbd2e7393624e455ce53c87965d1 (diff)
parent69405d3da98b48633b78a49403e4f9cdb7c6a0f5 (diff)
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Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie: "Core: - Fence destaging work - DRIVER_LEGACY to split off legacy drm drivers - drm_mm refactoring - Splitting drm_crtc.c into chunks and documenting better - Display info fixes - rbtree support for prime buffer lookup - Simple VGA DAC driver Panel: - Add Nexus 7 panel - More simple panels i915: - Refactoring GEM naming - Refactored vma/active tracking - Lockless request lookups - Better stolen memory support - FBC fixes - SKL watermark fixes - VGPU improvements - dma-buf fencing support - Better DP dongle support amdgpu: - Powerplay for Iceland asics - Improved GPU reset support - UVD/VEC powergating support for CZ/ST - Preinitialised VRAM buffer support - Virtual display support - Initial SI support - GTT rework - PCI shutdown callback support - HPD IRQ storm fixes amdkfd: - bugfixes tilcdc: - Atomic modesetting support mediatek: - AAL + GAMMA engine support - Hook up gamma LUT - Temporal dithering support imx: - Pixel clock from devicetree - drm bridge support for LVDS bridges - active plane reconfiguration - VDIC deinterlacer support - Frame synchronisation unit support - Color space conversion support analogix: - PSR support - Better panel on/off support rockchip: - rk3399 vop/crtc support - PSR support vc4: - Interlaced vblank timing - 3D rendering CPU overhead reduction - HDMI output fixes tda998x: - HDMI audio ASoC support sunxi: - Allwinner A33 support - better TCON support msm: - DT binding cleanups - Explicit fence-fd support sti: - remove sti415/416 support etnaviv: - MMUv2 refactoring - GC3000 support exynos: - Refactoring HDMI DCC/PHY - G2D pm regression fix - Page fault issues with wait for vblank There is no nouveau work in this tree, as Ben didn't get a pull request in, and he was fighting moving to atomic and adding mst support, so maybe best it waits for a cycle" * tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux: (1412 commits) drm/crtc: constify drm_crtc_index parameter drm/i915: Fix conflict resolution from backmerge of v4.8-rc8 to drm-next drm/i915/guc: Unwind GuC workqueue reservation if request construction fails drm/i915: Reset the breadcrumbs IRQ more carefully drm/i915: Force relocations via cpu if we run out of idle aperture drm/i915: Distinguish last emitted request from last submitted request drm/i915: Allow DP to work w/o EDID drm/i915: Move long hpd handling into the hotplug work drm/i915/execlists: Reinitialise context image after GPU hang drm/i915: Use correct index for backtracking HUNG semaphores drm/i915: Unalias obj->phys_handle and obj->userptr drm/i915: Just clear the mmiodebug before a register access drm/i915/gen9: only add the planes actually affected by ddb changes drm/i915: Allow PCH DPLL sharing regardless of DPLL_SDVO_HIGH_SPEED drm/i915/bxt: Fix HDMI DPLL configuration drm/i915/gen9: fix the watermark res_blocks value drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations drm/i915/gen9: minimum scanlines for Y tile is not always 4 drm/i915/gen9: fix the WaWmMemoryReadLatency implementation drm/i915/kbl: KBL also needs to run the SAGV code ...
Diffstat (limited to 'Documentation/gpu/drm-kms-helpers.rst')
-rw-r--r--Documentation/gpu/drm-kms-helpers.rst221
1 files changed, 120 insertions, 101 deletions
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 0b302fe..bb4254d 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -2,38 +2,45 @@
Mode Setting Helper Functions
=============================
-The plane, CRTC, encoder and connector functions provided by the drivers
-implement the DRM API. They're called by the DRM core and ioctl handlers
-to handle device state changes and configuration request. As
-implementing those functions often requires logic not specific to
-drivers, mid-layer helper functions are available to avoid duplicating
-boilerplate code.
-
-The DRM core contains one mid-layer implementation. The mid-layer
-provides implementations of several plane, CRTC, encoder and connector
-functions (called from the top of the mid-layer) that pre-process
-requests and call lower-level functions provided by the driver (at the
-bottom of the mid-layer). For instance, the
-:c:func:`drm_crtc_helper_set_config()` function can be used to
-fill the :c:type:`struct drm_crtc_funcs <drm_crtc_funcs>`
-set_config field. When called, it will split the set_config operation
-in smaller, simpler operations and call the driver to handle them.
-
-To use the mid-layer, drivers call
-:c:func:`drm_crtc_helper_add()`,
-:c:func:`drm_encoder_helper_add()` and
-:c:func:`drm_connector_helper_add()` functions to install their
-mid-layer bottom operations handlers, and fill the :c:type:`struct
-drm_crtc_funcs <drm_crtc_funcs>`, :c:type:`struct
-drm_encoder_funcs <drm_encoder_funcs>` and :c:type:`struct
-drm_connector_funcs <drm_connector_funcs>` structures with
-pointers to the mid-layer top API functions. Installing the mid-layer
-bottom operation handlers is best done right after registering the
-corresponding KMS object.
-
-The mid-layer is not split between CRTC, encoder and connector
-operations. To use it, a driver must provide bottom functions for all of
-the three KMS entities.
+The DRM subsystem aims for a strong separation between core code and helper
+libraries. Core code takes care of general setup and teardown and decoding
+userspace requests to kernel internal objects. Everything else is handled by a
+large set of helper libraries, which can be combined freely to pick and choose
+for each driver what fits, and avoid shared code where special behaviour is
+needed.
+
+This distinction between core code and helpers is especially strong in the
+modesetting code, where there's a shared userspace ABI for all drivers. This is
+in contrast to the render side, where pretty much everything (with very few
+exceptions) can be considered optional helper code.
+
+There are a few areas these helpers can grouped into:
+
+* Helpers to implement modesetting. The important ones here are the atomic
+ helpers. Old drivers still often use the legacy CRTC helpers. They both share
+ the same set of common helper vtables. For really simple drivers (anything
+ that would have been a great fit in the deprecated fbdev subsystem) there's
+ also the simple display pipe helpers.
+
+* There's a big pile of helpers for handling outputs. First the generic bridge
+ helpers for handling encoder and transcoder IP blocks. Second the panel helpers
+ for handling panel-related information and logic. Plus then a big set of
+ helpers for the various sink standards (DisplayPort, HDMI, MIPI DSI). Finally
+ there's also generic helpers for handling output probing, and for dealing with
+ EDIDs.
+
+* The last group of helpers concerns itself with the frontend side of a display
+ pipeline: Planes, handling rectangles for visibility checking and scissoring,
+ flip queues and assorted bits.
+
+Modeset Helper Reference for Common Vtables
+===========================================
+
+.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
+ :internal:
+
+.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
+ :doc: overview
Atomic Modeset Helper Functions Reference
=========================================
@@ -62,33 +69,27 @@ Atomic State Reset and Initialization
.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
:export:
-Modeset Helper Reference for Common Vtables
-===========================================
-
-.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
- :internal:
-
-.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
- :doc: overview
-
Legacy CRTC/Modeset Helper Functions Reference
==============================================
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
- :export:
+ :doc: overview
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
- :doc: overview
+ :export:
-Output Probing Helper Functions Reference
-=========================================
+Simple KMS Helper Reference
+===========================
-.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
- :doc: output probing helper overview
+.. kernel-doc:: include/drm/drm_simple_kms_helper.h
+ :internal:
-.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
:export:
+.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
+ :doc: overview
+
fbdev Helper Functions Reference
================================
@@ -110,6 +111,43 @@ Framebuffer CMA Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
:export:
+Bridges
+=======
+
+Overview
+--------
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :doc: overview
+
+Default bridge callback sequence
+--------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :doc: bridge callbacks
+
+
+Bridge Helper Reference
+-------------------------
+
+.. kernel-doc:: include/drm/drm_bridge.h
+ :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+ :export:
+
+Panel Helper Reference
+======================
+
+.. kernel-doc:: include/drm/drm_panel.h
+ :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_panel.c
+ :export:
+
+.. kernel-doc:: drivers/gpu/drm/drm_panel.c
+ :doc: drm panel
+
Display Port Helper Functions Reference
=======================================
@@ -158,9 +196,21 @@ MIPI DSI Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
:export:
+Output Probing Helper Functions Reference
+=========================================
+
+.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+ :doc: output probing helper overview
+
+.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
+ :export:
+
EDID Helper Functions Reference
===============================
+.. kernel-doc:: include/drm/drm_edid.h
+ :internal:
+
.. kernel-doc:: drivers/gpu/drm/drm_edid.c
:export:
@@ -176,18 +226,6 @@ Rectangle Utilities Reference
.. kernel-doc:: drivers/gpu/drm/drm_rect.c
:export:
-Flip-work Helper Reference
-==========================
-
-.. kernel-doc:: include/drm/drm_flip_work.h
- :doc: flip utils
-
-.. kernel-doc:: include/drm/drm_flip_work.h
- :internal:
-
-.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
- :export:
-
HDMI Infoframes Helper Reference
================================
@@ -202,59 +240,40 @@ libraries and hence is also included here.
.. kernel-doc:: drivers/video/hdmi.c
:export:
-Plane Helper Reference
-======================
-
-.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
- :export:
-
-.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
- :doc: overview
+Flip-work Helper Reference
+==========================
-Tile group
-----------
+.. kernel-doc:: include/drm/drm_flip_work.h
+ :doc: flip utils
-.. kernel-doc:: drivers/gpu/drm/drm_crtc.c
- :doc: Tile group
+.. kernel-doc:: include/drm/drm_flip_work.h
+ :internal:
-Bridges
-=======
+.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
+ :export:
-Overview
---------
+Plane Helper Reference
+======================
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:doc: overview
-Default bridge callback sequence
---------------------------------
-
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
- :doc: bridge callbacks
-
-.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
+.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:export:
-Panel Helper Reference
-======================
-
-.. kernel-doc:: include/drm/drm_panel.h
- :internal:
+Tile group
+==========
-.. kernel-doc:: drivers/gpu/drm/drm_panel.c
- :export:
+# FIXME: This should probably be moved into a property documentation section
-.. kernel-doc:: drivers/gpu/drm/drm_panel.c
- :doc: drm panel
+.. kernel-doc:: drivers/gpu/drm/drm_crtc.c
+ :doc: Tile group
-Simple KMS Helper Reference
-===========================
+Auxiliary Modeset Helpers
+=========================
-.. kernel-doc:: include/drm/drm_simple_kms_helper.h
- :internal:
+.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
+ :doc: aux kms helpers
-.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
+.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
:export:
-
-.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
- :doc: overview
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