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authorBrian Starkey <brian.starkey@arm.com>2017-03-29 17:42:32 +0100
committerLiviu Dudau <Liviu.Dudau@arm.com>2018-06-20 15:27:49 +0100
commit935774cd71fe604cc8ed24adcb507d7784255672 (patch)
tree61aa8d66732c288df25d002c17620521b0900fa1 /Documentation/gpu
parentf664a52695429b68afb4e130a0f69cd5fd1fec86 (diff)
drm: Add writeback connector type
Writeback connectors represent writeback engines which can write the CRTC output to a memory framebuffer. Add a writeback connector type and related support functions. Drivers should initialize a writeback connector with drm_writeback_connector_init() which takes care of setting up all the writeback-specific details on top of the normal functionality of drm_connector_init(). Writeback connectors have a WRITEBACK_FB_ID property, used to set the output framebuffer, and a WRITEBACK_PIXEL_FORMATS blob used to expose the supported writeback formats to userspace. When a framebuffer is attached to a writeback connector with the WRITEBACK_FB_ID property, it is used only once (for the commit in which it was included), and userspace can never read back the value of WRITEBACK_FB_ID. WRITEBACK_FB_ID can only be set if the connector is attached to a CRTC. Changes since v1: - Added drm_writeback.c + documentation - Added helper to initialize writeback connector in one go - Added core checks - Squashed into a single commit - Dropped the client cap - Writeback framebuffers are no longer persistent Changes since v2: Daniel Vetter: - Subclass drm_connector to drm_writeback_connector - Relax check to allow CRTC to be set without an FB - Add some writeback_ prefixes - Drop PIXEL_FORMATS_SIZE property, as it was unnecessary Gustavo Padovan: - Add drm_writeback_job to handle writeback signalling centrally Changes since v3: - Rebased - Rename PIXEL_FORMATS -> WRITEBACK_PIXEL_FORMATS Chances since v4: - Embed a drm_encoder inside the drm_writeback_connector to reduce the amount of boilerplate code required from the drivers that are using it. Changes since v5: - Added Rob Clark's atomic_commit() vfunc to connector helper funcs, so that writeback jobs are committed from atomic helpers - Updated create_writeback_properties() signature to return an error code rather than a boolean false for failure. - Free writeback job with the connector state rather than when doing the cleanup_work() Changes since v7: - fix extraneous use of out_fence that is only introduced in a subsequent patch. Changes since v8: - whitespace changes pull from subsequent patch Changes since v9: - Revert the v6 changes that free the writeback job in the connector state cleanup and return to doing it in the cleanup_work() function Signed-off-by: Brian Starkey <brian.starkey@arm.com> [rebased and fixed conflicts] Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com> [rebased and added atomic_commit() vfunc for writeback jobs] Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Liviu Dudau <liviu.dudau@arm.com> Reviewed-by: Eric Anholt <eric@anholt.net> Link: https://patchwork.freedesktop.org/patch/229037/
Diffstat (limited to 'Documentation/gpu')
-rw-r--r--Documentation/gpu/drm-kms.rst9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index e233c2626bd0..4f6f113a7f5d 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -373,6 +373,15 @@ Connector Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_connector.c
:export:
+Writeback Connectors
+--------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_writeback.c
+ :doc: overview
+
+.. kernel-doc:: drivers/gpu/drm/drm_writeback.c
+ :export:
+
Encoder Abstraction
===================