Since the output has 1:1 relationship between connectors and encoders,
and the driver is relying on the atomic helpers, remove the custom
best_encoder() and let the core call drm_atomic_helper_best_encoder().
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170927182317.GA8249@Haneen
We need the following things to happen in sequence:
DSI host creation
DSI device creation in the panel driver (needs DSI host)
DSI device attach from panel to host.
DSI drm_panel_add()
DSI encoder creation
DSI encoder's DRM panel/bridge attach
Unless we allow device creation while the host isn't up yet, we need
to break the -EPROBE_DEFER deadlock between the panel driver looking
up the host and the host driver looking up the panel. We can do so by
moving the DSI host creation outside of the component bind loop, and
the panel/bridge lookup/attach into the component bind process.
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20170815234722.20700-3-eric@anholt.net
Reviewed-by: Archit Taneja <architt@codeaurora.org>
The incoming mode might have a missing vrefresh field if it came from
drmModeSetCrtc(), which the kernel is supposed to calculate using
drm_mode_vrefresh(). We could either use that or the adjusted_mode's
original vrefresh value.
However, we can maintain a more exact vrefresh value (not just the
integer approximation), by scaling by the ratio of our clocks.
v2: Use math suggested by Andrzej Hajda instead.
v3: Simplify math now that adjusted_mode->clock isn't padded.
v4: Drop some parens.
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20170815234722.20700-2-eric@anholt.net
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
This is a continuation of a previous commit ("drm: introduce drm_dev_{get/put}
functions") to replace all references to drm_dev_unref() in drm core files with
drm_dev_put().
Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170926170400.GA7671@aishwarya
For maintaining consistency with kernel coding style replace
reference/unreference in ref counting functions with get/put.
The following cocci script was used to generate the tilcdc patch:
@@
expression ex;
@@
(
-drm_framebuffer_unreference(ex);
+drm_framebuffer_put(ex);
|
-drm_dev_unref(ex);
+drm_dev_put(ex);
|
-drm_framebuffer_reference(ex);
+drm_framebuffer_get(ex);
)
Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Acked-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/3f2f592f6ea28adfea3fd8b70421b2fab38f0b94.1506413698.git.aishpant@gmail.com
Reference counting functions in the kernel typically use get/put suffixes. For
maintaining coding style consistency, introduce drm_dev_{get/put} functions. All
callers of drm_dev_ref() API have been converted in this patch and hence it has
been dropped while the drm_dev_unref() API with non-trivial number of users
remains for compatibility.
The semantic patch scripts/coccinelle/api/drm-get-put.cocci has been updated
with the new helper for conversion of drm_dev_unref() to drm_dev_put()
Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/6babda56134035a98220d5d37a4fd4048df214ce.1506413698.git.aishpant@gmail.com
Remove obsolete comment which was initially added in 2008 to annotate
that idr_find() was used before idr_remove() since idr_remove() didn't
use to return feedback. The comment now is irrelevant with
commit f6cd7daecf ("drm: Release driver references to handle before
making it available again").
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170921210424.GA21951@Haneen
Due to inconsistency of how various legacy drivers implemented DPMS
the DPMS uabi has a lot of quirks. Atomic standardizes this, but
drivers using the DPMS support can't rely on that since legacy drivers
still exist.
Laurent asked for this.
v2:
Improve commit message and explain that DPMS doesn't really exist for
the atomic ioctl (it's "ACTIVE" on the CRTC instead).
Text polish from Eric's review.
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170920225957.16278-1-daniel.vetter@ffwll.ch
Add drm_kms_helper.edid_firmware module parameter with param ops hooks
to set drm.edid_firmware instead, for backwards compatibility.
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170918182003.22238-2-jani.nikula@intel.com
Handle debugfs override edid and firmware edid at the low level to
transparently and completely replace the real edid. Previously, we
practically only used the modes from the override EDID, and none of the
other data, such as audio parameters.
This change also prevents actual EDID reads when the EDID is to be
overridden, but retains the DDC probe. This is useful if the reason for
preferring override EDID are problems with reading the data, or
corruption of the data.
Move firmware EDID loading from helper to core, as the functionality
moves to lower level as well. This will result in a change of module
parameter from drm_kms_helper.edid_firmware to drm.edid_firmware, which
arguably makes more sense anyway.
Some future work remains related to override and firmware EDID
validation. Like before, no validation is done for override EDID. The
firmware EDID is validated separately in the loader. Some unification
and deduplication would be in order, to validate all of them at the
drm_do_get_edid() level, like "real" EDIDs.
v2: move firmware loading to core
v3: rebase, commit message refresh
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1e8a710bcac46e5136c1a7b430074893c81f364a.1505203831.git.jani.nikula@intel.com
This patch replace instances of dev_info/err/debug with
DRM_DEV_INFO/ERROR/WARN respectively inorder to use a drm-formatted
specific log messages. Issue corrected with the help of the following
Coccinelle script:
@r@
@@
(
-dev_info
+DRM_DEV_INFO
|
-dev_err
+DRM_DEV_ERROR
|
-dev_dbg
+DRM_DEV_DEBUG
)
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170915083603.GA18992@Haneen
No need to put out a driver registered message since drm_dev_register()
does that now. SPI speed is an important metric when dealing with
display problems, so retain that info.
Cc: David Lechner <david@lechnology.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: David Lechner <david@lechnology.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1504883250-43487-8-git-send-email-noralf@tronnes.org
GEM lookup failure can easily be triggered by userspace so make
it a debug message, not an error message.
Also remove unnecessary inner parentheses and fix alphabetical
struct declaration order.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1505147865-18194-2-git-send-email-noralf@tronnes.org
The HDMI codec platform data is global driver state shared by all
instances. As such it should not be modified (and is not), to make this
explicit declare it as const.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170905121018.11477-4-lars@metafoo.de
Fall back to polling the connector for connect and disconnect events when
no interrupt is specified. Otherwise these events will not be noticed and
monitor hotplug does not work.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170905121018.11477-3-lars@metafoo.de
The adv7511 driver keeps a private copy of the EDID in its driver state
struct. But this copy is only used in adv7511_get_modes() where it is also
retrieved, so there is no need to keep this extra copy around.
If a need to access the EDID elsewhere in the driver ever arises the copy
that is stored in the connector can be used. This copy is accessible
through drm_connector_get_edid().
Note, this patch removes the NULL check of the EDID before passing it to
drm_detect_hdmi_monitor(), but that is fine since the function correctly
handles the case where the EDID is NULL.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170905121018.11477-2-lars@metafoo.de
Currently adv7511_get_modes() bails out early when no EDID could be
retrieved. This leaves the previous EDID in place, which is typically not
the intended behavior and might confuse applications. Instead the EDID
should be cleared when no EDID could be retrieved.
All functions that are called after the EDID check handle the case where
the EDID is NULL just fine and exhibit the expected behavior, so just drop
the check.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170905121018.11477-1-lars@metafoo.de
Pass DRM_MODESET_ACQUIRE_INTERRUPTIBLE to acquire_init, and handle
drm_modeset_backoff which can now fail by returning the error.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-6-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Pass DRM_MODESET_ACQUIRE_INTERRUPTIBLE to acquire_init, and handle
drm_modeset_backoff which can now fail by returning the error.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-5-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Pass DRM_MODESET_ACQUIRE_INTERRUPTIBLE to acquire_init, and handle
drm_modeset_backoff which can now fail by returning the error.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-4-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Pass DRM_MODESET_ACQUIRE_INTERRUPTIBLE to acquire_init, and
handle drm_modeset_backoff which can now fail by returning the error.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-3-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
When we want to make drm_atomic_commit interruptible, there are a lot of
places that call the lock function, which we don't have control over.
Rather than trying to convert every single one, it's easier to toggle
interruptible waiting per acquire_ctx. If drm_modeset_acquire_init is
called with DRM_MODESET_ACQUIRE_INTERRUPTIBLE, then we will perform
interruptible waits in drm_modeset_lock and drm_modeset_backoff.
Changes since v1:
- Fix locking example in drm_modeset_lock.c to be compatible
with interruptible waiting (xexaxo) and make it default.
Uninterruptible waiting shouldn't happen except in corner cases,
but the example will still apply if the flag is removed.
- Add drm_modeset_lock_single_interruptible() to documentation.
- Fix dead link to removed drm_modeset_lock_interruptible() in
drm_modeset_lock().
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-2-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
This makes use of the drm_simple_display_pipe_attach_bridge()
call and removes the two calls removing the bridge, which were
erroneous: they unregister the bridge which is not what
we want, we just want to unreference it and that is already
handled by the core.
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170910220801.28588-1-linus.walleij@linaro.org
The POWER_DOWN_PHY and POWER_UP_PHY sideband message transactions allow
the source to reqest any node in a mst path or a whole path to be
powered down or up. This allows drivers to target a specific sink in the
MST topology, an improvement over just power managing the imediate
downstream device. Secondly, since the request-reply protocol waits for an
ACK, we can be sure that a downstream sink has enough time to respond to a
power up/down request.
v2: Fix memory leak (Lyude)
Cc: Lyude <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170907001458.9399-1-dhinakaran.pandiyan@intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Make __drm_object_property_get_value() static to fix the following
sparse warning:
drm_mode_object.c:250:5: warning: symbol '__drm_object_property_get_value' was not declared. Should it be static?
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes: 4a97a3da42 ("drm: Don't update property values for atomic drivers")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901165328.24459-4-ville.syrjala@linux.intel.com
Reviewed-by: Thierry Reding <treding@nvidia.com>
drm_get_link_status_name() isn't used so kill it.
Fixes the following sparse warning:
drm_connector.c:618:1: warning: symbol 'drm_get_link_status_name' was not declared. Should it be static?
Cc: Manasi Navare <manasi.d.navare@intel.com>
Fixes: 40ee6fbef7 ("drm: Add a new connector atomic property for link status")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901165328.24459-3-ville.syrjala@linux.intel.com
Reviewed-by: Thierry Reding <treding@nvidia.com>
Fix the following sparse warnings by making functions static:
drm_syncobj.c:420:5: warning: symbol 'drm_syncobj_import_sync_file_fence' was not declared. Should it be static?
drm_syncobj.c:441:5: warning: symbol 'drm_syncobj_export_sync_file' was not declared. Should it be static?
Cc: Dave Airlie <airlied@redhat.com>
Fixes: 3ee45a3b53 ("drm/syncobj: add sync_file interaction. (v1.2)")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901165328.24459-1-ville.syrjala@linux.intel.com
Reviewed-by: Thierry Reding <treding@nvidia.com>
The ARM reference designs in the Versatile family: Integrator,
Versatile and RealView can make use of the new DRM driver as well.
We just need to create a bit of platform-specific code for them
that we isolate to its own file.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-7-linus.walleij@linaro.org
The old codebase has a delay between enabling and powering up the
PL11x.
According to the manual for PL110, ARM DDI 0161E page 1-5 and
the PL111 manual ARM DDI 0293C page 1-6, the power sequence should
be such that once Vdd is stable (which we assume it is at boot)
LCDEN is enabled first and then CLPOWER should be enabled
"after the signals have stabilized" and this is said to
be display-dependent. The old codebase uses 20ms.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-5-linus.walleij@linaro.org
We detect and enable the use of the PL110 variant, an earlier
incarnation of PL111. The only real difference is that the
control and interrupt enable registers have swapped place.
The Versatile AB and Versatile PB have a variant inbetween
PL110 and PL111, it is PL110 but they have already swapped the
two registers so those two need a bit of special handling.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-4-linus.walleij@linaro.org
This replaces the custom connector in the PL111 with the
panel bridge helper.
This works nicely for all standard panels, but since there
are several PL11x-based systems that will need to use the dumb
VGA connector bridge we use drm_of_find_panel_or_bridge()
and make some headroom for dealing with bridges that are
not panels as well, and drop a TODO in the code.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-3-linus.walleij@linaro.org
If we want to have vblank on both pipelines at the same time, we need
to call drm_vblank_init with num_crtcs = 2.
Instead, since the crtc init calls correctly set mode_config.num_crtc,
we can move the drm_vblank_init call to after the crtc init code is
called, which is the component bind part. Then we can just pass
mode_config.num_crtc in.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-8-wens@csie.org
The TCON has a mux to select the source of the data to display.
This mux includes selecting the display backends. On the A31,
which has two display pipelines, this mux can let the TCON
select either backend as its data source. Although the muxing
can be changed on the fly, DRM needs to be able to group a
bunch of layers such that they get switched to another crtc
together. This is because the display backend does the layer
compositing, while the TCON generates the display timings.
This constraint is not supported by DRM.
Here we simply pair up backends and TCONs with the same ID.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-7-wens@csie.org
Now that sun4i_tcon_find_engine_traverse() usage is restricted to the
single input case, we can remove the for_each_available_child_of_node
loop.
While at it, consolidate all the of_node_put calls into a common exit
path.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-6-wens@csie.org
The device tree binding for sun4i-drm says:
For all connections between components up to the TCONs in the display
pipeline, when there are multiple components of the same type at the
same depth, the local endpoint ID must be the same as the remote
component's index. For example, if the remote endpoint is Frontend 1,
then the local endpoint ID must be 1.
We should be able to get the TCON's ID directly from any of the remote
endpoints from its input port. With the ID, we can then go through the
list of registered engines and find a matching one by ID.
However the A31 device tree is incorrect. We assumed that there were no
cross pipeline connections between the backends and TCONs. As a result,
in all the endpoints between the backends and TCONs of the second
display pipeline, the endpoint IDs were incorrectly set to 0, when in
fact they should've been set to 1.
To maintain compatibility with this incorrect device tree, we first
check if the TCON's input port has 1 or many endpoints. If there are
more than 1, then it is likely a fixed version, and we can proceed
with the new method. If there is only 1 endpoint, then it is possibly
an incorrect version, or it could be the SoC only has one pipeline.
In either case we fall back to using the old method of traversing
the input connections to find a matching engine, and then get its
ID.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-5-wens@csie.org
The patch b317fa3ba1 ("drm/sun4i: tcon: Find matching display backend
by device node matching") assumed a one-to-one mapping between TCONs
and backends. This turned out wrong, as we found muxing controls in the
TCON of the A31, and undocumented usage of the backend output selector
of the A20.
Make sun4i_tcon_find_engine() bail out if the current node has multiple
input connections.
Fixes: b317fa3ba1 ("drm/sun4i: tcon: Find matching display backend
by device node matching")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-4-wens@csie.org
The encoder drivers use drm_of_find_possible_crtcs to get upstream
crtcs from the device tree using of_graph. For the results to be
correct, encoders must be probed/bound after _all_ crtcs have been
created. The existing code uses a depth first recursive traversal
of the of_graph, which means the encoders downstream of the TCON
get add right after the first TCON. The second TCON or CRTC will
never be properly associated with encoders connected to it.
Other platforms, such as Rockchip, deal with this by probing all
CRTCs first, then all subsequent components. This is easy to do
since the CRTCs correspond to just one device node, and are the
first nodes in the pipeline.
However with Allwinner SoCs, the function of the CRTC is split
between the display backend (DE 1.0) or mixer (DE 2.0), which does
scan-out and compositing, and the TCON, which generates the display
timing signals. Further complicating the process, there may be a
Dynamic Range Controller between the backend and the TCON. Also, the
backend is preceded by the frontend, with a Display Enhancement Unit
possibly in between.
In a dual display pipeline setup, both frontends can feed either
backend, and both backends can feed either TCON. We want all
components of the same type to be added before the next type in the
pipeline. Fortunately, the pipelines are perfectly symmetric, i.e.
components of the same type are at the same depth when counted from
the frontend. The only exception is the third pipeline in the A80
SoC, which we do not support anyway.
Hence we can use a breadth first search traversal order to add
components. We do not need to check for duplicates. The component
matching system handles this for us.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908075016.18657-3-wens@csie.org
