[PATCH v8 0/5] Add support for iMX8MQ Display Controller Subsystem

From: Laurentiu Palcu
Date: Fri Jul 24 2020 - 05:08:26 EST

From: Laurentiu Palcu <laurentiu.palcu@xxxxxxx>


This patchset adds initial DCSS support for iMX8MQ chip. Initial support
includes only graphics plane support (no video planes), no HDR10 capabilities,
no graphics decompression (only linear, tiled and super-tiled buffers allowed).

Support for the rest of the features will be added incrementally, in subsequent

The patchset was tested with both HDP driver (in the downstream tree) and the upstream
MIPI-DSI driver (with a couple of patches on top, to make it work correctly with DCSS).


Changes in v8:
* Removed 'select RESET_CONTROLLER" from Kconfig as Philipp pointed
out. SRC is not used in DCSS driver;
* Nothing else changed;

Changes in v7:
* Added a patch to initialize the connector using the drm_bridge_connector
API as Sam suggested. Tested it using NWL_DSI and ADV7535 with
Guido's patch [1] applied and one fix for ADV [2]. Also, some extra
patches for ADV and NWL were needed, from our downstream tree, which
will be upstreamed soon by their author;
* Rest of the patches are untouched;

[1] https://lists.freedesktop.org/archives/dri-devel/2020-July/273025.html
[2] https://lists.freedesktop.org/archives/dri-devel/2020-July/273132.html

Changes in v6:
* Addressed Rob's comment and added "additionalProperties: false" at
the end of the bindings' properties. However, this change surfaced
an issue with the assigned-clock* properties not being documented in
the properties section. Added the descriptions and the bindings patch
will need another review;
* Added an entry for DCSS driver in the MAINTAINERS file;
* Removed the component framework patch altogether;

Changes in v5:
* Rebased to latest;
* Took out component framework support and made it a separate patch so
that people can still test with HDP driver, which makes use of it.
But the idea is to get rid of it once HDP driver's next versions
will remove component framework as well;
* Slight improvement to modesetting: avoid cutting off the pixel clock
if the new mode and the old one are equal. Also, in this case, is
not necessary to wait for DTG to shut off. This would allow to switch
from 8b RGB to 12b YUV422, for example, with no interruptions (at least
from DCSS point of view);
* Do not fire off CTXLD when going to suspend, unless it still has
entries that need to be committed to DCSS;
* Addressed Rob's comments on bindings;

Changes in v4:
* Addressed Lucas and Philipp's comments:
* Added DRM_KMS_CMA_HELPER dependency in Kconfig;
* Removed usage of devm_ functions since I'm already doing all the
clean-up in the submodules_deinit();
* Moved the drm_crtc_arm_vblank_event() in dcss_crtc_atomic_flush();
* Removed en_completion variable from dcss_crtc since this was
introduced mainly to avoid vblank timeout warnings which were fixed
by arming the vblank event in flush() instead of begin();
* Removed clks_on and irq_enabled flags since all the calls to
enabling/disabling clocks and interrupts were balanced;
* Removed the custom atomic_commit callback and used the DRM core
helper and, in the process, got rid of a workqueue that wasn't
necessary anymore;
* Fixed some minor DT binding issues flagged by Philipp;
* Some other minor changes suggested by Lucas;
* Removed YUV formats from the supported formats as these cannot work
without the HDR10 module CSCs and LUTs. Will add them back when I
will add support for video planes;

Changes in v3:
* rebased to latest linux-next and made it compile as drmP.h was
* removed the patch adding the VIDEO2_PLL clock. It's already applied;
* removed an unnecessary 50ms sleep in the dcss_dtg_sync_set();
* fixed a a spurious hang reported by Lukas Hartmann and encountered
by me several times;
* mask DPR and DTG interrupts by default, as they may come enabled from

Changes in v2:
* Removed '0x' in node's unit-address both in DT and yaml;
* Made the address region size lowercase, to be consistent;
* Removed some left-over references to P010;
* Added a Kconfig dependency of DRM && ARCH_MXC. This will also silence compilation
issues reported by kbuild for other architectures;

Laurentiu Palcu (5):
drm/imx: compile imx directory by default
drm/imx: Add initial support for DCSS on iMX8MQ
drm/imx/dcss: use drm_bridge_connector API
MAINTAINERS: Add entry for i.MX 8MQ DCSS driver
dt-bindings: display: imx: add bindings for DCSS

.../bindings/display/imx/nxp,imx8mq-dcss.yaml | 104 +++
drivers/gpu/drm/Makefile | 2 +-
drivers/gpu/drm/imx/Kconfig | 2 +
drivers/gpu/drm/imx/Makefile | 1 +
drivers/gpu/drm/imx/dcss/Kconfig | 8 +
drivers/gpu/drm/imx/dcss/Makefile | 6 +
drivers/gpu/drm/imx/dcss/dcss-blkctl.c | 70 ++
drivers/gpu/drm/imx/dcss/dcss-crtc.c | 219 +++++
drivers/gpu/drm/imx/dcss/dcss-ctxld.c | 424 +++++++++
drivers/gpu/drm/imx/dcss/dcss-dev.c | 325 +++++++
drivers/gpu/drm/imx/dcss/dcss-dev.h | 177 ++++
drivers/gpu/drm/imx/dcss/dcss-dpr.c | 562 ++++++++++++
drivers/gpu/drm/imx/dcss/dcss-drv.c | 138 +++
drivers/gpu/drm/imx/dcss/dcss-dtg.c | 409 +++++++++
drivers/gpu/drm/imx/dcss/dcss-kms.c | 198 +++++
drivers/gpu/drm/imx/dcss/dcss-kms.h | 44 +
drivers/gpu/drm/imx/dcss/dcss-plane.c | 405 +++++++++
drivers/gpu/drm/imx/dcss/dcss-scaler.c | 826 ++++++++++++++++++
drivers/gpu/drm/imx/dcss/dcss-ss.c | 180 ++++
20 files changed, 4107 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/display/imx/nxp,imx8mq-dcss.yaml
create mode 100644 drivers/gpu/drm/imx/dcss/Kconfig
create mode 100644 drivers/gpu/drm/imx/dcss/Makefile
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-blkctl.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-crtc.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-ctxld.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dev.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dev.h
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dpr.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-drv.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dtg.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-kms.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-kms.h
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-plane.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-scaler.c
create mode 100644 drivers/gpu/drm/imx/dcss/dcss-ss.c