drm/doc: Light drm-kms-helper.rst cleanup

- Move the common vtable stuff to the top
- Move "Tile Group" to a more appropriate heading level
- Throw away the old intro for the crtc helpers (it's entirely stale,
  e.g. helpers have become modular years ago), and replace it with a
  general intro about the motivation behind helpers.
- Reorder helpers to group them together a bit better, and explain
  that grouping in the intro.
- Make sure the introductory DOC section is always first.

v2:
- Remove bogus files accidentally added (Sean).
- Spelling fixes (Sean).

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-2-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2016-08-12 22:48:38 +02:00
parent 62cacc7939
commit bcb32b691c
2 changed files with 109 additions and 106 deletions

View file

@ -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 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.
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.
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.
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.
There are a few areas these helpers can grouped into:
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.
* 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:
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
:doc: overview
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
.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
:export:
Simple KMS Helper Reference
===========================
.. kernel-doc:: include/drm/drm_simple_kms_helper.h
:internal:
.. 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 +111,36 @@ 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
.. 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
=======================================
@ -158,6 +189,15 @@ 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
===============================
@ -176,18 +216,6 @@ 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 +230,31 @@ libraries and hence is also included here.
.. kernel-doc:: drivers/video/hdmi.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:
Plane Helper Reference
======================
.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:export:
.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:doc: overview
.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
:export:
Tile group
----------
==========
# FIXME: This should probably be moved into a property documentation section
.. kernel-doc:: drivers/gpu/drm/drm_crtc.c
:doc: Tile group
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
.. 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
Simple KMS Helper Reference
===========================
.. kernel-doc:: include/drm/drm_simple_kms_helper.h
:internal:
.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
:export:
.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
:doc: overview

View file

@ -33,6 +33,9 @@ Primary Nodes, DRM Master and Authentication
.. kernel-doc:: include/drm/drm_auth.h
:internal:
Open-Source Userspace Requirements
==================================
Render nodes
============