Commit 917de180 ("drm: rcar-du: Implement universal plane support")
made the number of planes per group dynamic, but didn't update all loops
over the planes array, resulting in out-of-bound accesses on DU
instances that have an odd number of CRTCs (such as the R8A7790). Fix
it.

Fixes: 917de180 ("drm: rcar-du: Implement universal plane support")
Cc: stable@vger.kernel.org
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The number of CRTCs in a group is only used to implement plane
initialization for now, but is also needed to implement pre-association
of planes to CRTCs. Store it in the group structure instead of computing
it on demand.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All other cast functions are named without using "du", make the plane
state cast consistent with them.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The rcar_du_planes structure contains a single field and is only
instantiated in the rcar_du_group structure. Embed it directly and
remove the rcar_du_planes structure.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The plane property objects are instantiated once per CRTC group, while
they should be instantiated once globally for the device. Fix this and
move them to the rcar_du_device structure.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Plane state duplication takes a reference to the framebuffer stored in
the state, but state destroy doesn't release it. This causes a reference
leak. Fix it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The plane allocator has been inherently racy since the beginning of the
transition to atomic updates, as the allocator lock is released between
free plane check (at .atomic_check() time) and the reservation (at
.atomic_update() time).

To fix it, create a new allocator solely based on the atomic plane
states without keeping any external state and perform allocation in the
.atomic_check() handler. The core idea is to replace the free planes
bitmask with a collective knowledge based on the allocated hardware
plane(s) for each KMS plane. The allocator then loops over all plane
states to compute the free planes bitmask, allocates hardware planes
based on that bitmask, and stores the result back in the plane states.

For this to work we need to access the current state of planes not
touched by the atomic update. To ensure that it won't be modified, we
need to lock all planes using drm_atomic_get_plane_state(). This
effectively serializes atomic updates from .atomic_check() up to
completion, either when swapping the states if the check step has
succeeded, or when freeing the states if the check step has failed.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The format stored in the rcar_du_plane structure is part of the plane
state. Move it to the rcar_du_plane_state structure and precompute it in
the .atomic_check() handler.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The crtc and enabled fields duplicates information stored in the plane
state. Use the plane state instead and remove the fields.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Now that the plane setup code isn't called outside of the plane
implementation, it can be simplified by merging the
rcar_du_plane_compute_base() and rcar_du_plane_update_base() functions.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Allow setting up plane properties atomically using the plane
set_property atomic helper. The properties are now stored in the plane
state (requiring subclassing it) and applied when updating the planes.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The atomic page flip helper implements the page flip operation using
asynchronous commits.

As the legacy page flip was the last CRTC operation that needed direct
access to plane setup, the plane setup functions can now become private
to the plane implementation.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This removes the legacy plane update code. Wire up the default atomic
check and atomic commit mode config helpers as needed by the plane
update atomic helpers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The plane source and destination size and positions are stored in the
plane state, and a private copy is kept in the rcar_du_plane objects.
Remove the private copy as it just duplicates the state.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Hook up the default .reset(), .atomic_duplicate_state() and
.atomic_free_state() helpers to ensure that state objects are properly
created and destroyed, and call drm_mode_config_reset() at init time to
create the initial state objects.

Framebuffer reference count also gets maintained automatically by the
transitional helpers except for the legacy page flip operation. Maintain
it explicitly there.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use the new CRTC atomic transitional helpers drm_helper_crtc_mode_set()
and drm_helper_crtc_mode_set_base() to implement the CRTC .mode_set and
.mode_set_base operations. This delegates primary plane configuration to
the plane .atomic_update and .atomic_disable operations, removing
duplicate code from the CRTC implementation.

There is now no code path available to the driver in which to drop the
reference to the CRTC acquired in the .prepare() operation if an error
then occurs. The driver thus now leaks a reference if an error occurs
during mode set. So be it, this will be fixed in a further step of the
atomic update transition.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Implement the CRTC .atomic_begin() and .atomic_flush() operations, the
plane .atomic_check(), .atomic_update() and operations, and use the
transitional atomic helpers to implement the plane update and disable
operations on top of the new atomic operations.

The plane setup code can't be moved out of the CRTC start function
completely yet, as the atomic code paths are not taken every time the
CRTC needs to be started. This results in some code duplication that
will be fixed after switching to atomic updates completely.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The hardware plane allocator loops over all planes to find free
candidates. However, instead of looping over the number of hardware
planes, it loops over the number of software planes, which happens to be
larger by one unit. This has no effect in practise as the extra plane is
always cleared in the mask of free planes, but it should still be fixed
for correctness.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Explicitly create the CRTC primary plane instead of relying on the core
helpers to do so. This simplifies the plane logic by merging the KMS and
software planes.

Reject plane API operations on the primary planes for now, as that code
will anyway be refactored when implementing support for atomic updates.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Accept interlaced modes on the VGA and HDMI connectors and configure the
hardware accordingly.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The PnMWR register containing the plane stride must be programmed with
correct stride values for both the luma and chroma planes when using a
multiplanar format. Fix it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The "Renesas Corporation" listed in the copyright notice doesn't exist.
Replace it with "Renesas Electronics Corporation" and update the
copyright years.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

When setting a new frame buffer with the mode set base operation the
pitch value might change. Set the hardware plane pitch register at the
same time as the plane base address in the rcar_du_plane_update_base()
function to make sure the pitch value always matches the frame buffer.

Cc: stable@vger.kernel.org
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R8A7790 DU has 3 CRTCs, split in two groups. Support them.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R8A7779 DU is split in per-CRTC resources (scan-out engine, blending
unit, timings generator, ...) and device-global resources (start/stop
control, planes, ...) shared between the two CRTCs.

The R8A7790 introduced a third CRTC with its own set of global resources
This would be modeled as two separate DU device instances if it wasn't
for a handful or resources that are shared between the three CRTCs
(mostly related to input and output routing). For this reason the
R8A7790 DU must be modeled as a single device with three CRTCs, two sets
of "semi-global" resources, and a few device-global resources.

Introduce a new rcar_du_group driver-specific object, without any real
counterpart in the DU documentation, that models those semi-global
resources.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The functions initialize or register all planes, rename them
accordingly.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R8A7790 DU documentation contains further information regarding the
plane Y source coordinate. Update the comment accordingly.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R-Car Display Unit (DU) DRM driver supports both superposition
processors and all eight planes in RGB and YUV formats with alpha
blending.

Only VGA and LVDS encoders and connectors are currently supported.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>