Commit '80253168dbfd ("drm: of: Lookup if child node has panel or
bridge")' attempted to simplify the case of expressing a simple panel
under a DSI controller, by assuming that the first non-graph child node
was a panel or bridge.
Unfortunately for non-trivial cases the first child node might not be a
panel or bridge. Examples of this can be a aux-bus in the case of
DisplayPort, or an opp-table represented before the panel node.
In these cases the reverted commit prevents the caller from ever finding
a reference to the panel.
This reverts commit '80253168dbfd ("drm: of: Lookup if child node has
panel or bridge")', in favor of using an explicit graph reference to the
panel in the trivial case as well.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220420231230.58499-2-bjorn.andersson@linaro.org
Commit '80253168dbfd ("drm: of: Lookup if child node has panel or
bridge")' introduced the ability to describe a panel under a display
controller without having to use a graph to connect the controller to
its single child panel (or bridge).
The implementation of this would find the first non-graph node and
attempt to acquire the related panel or bridge. This prevents cases
where any other child node, such as a aux bus for a DisplayPort
controller, or an opp-table to find the referenced panel.
Commit '67bae5f28c89 ("drm: of: Properly try all possible cases for
bridge/panel detection")' attempted to solve this problem by not
bypassing the graph reference lookup before attempting to find the panel
or bridge.
While this does solve the case where a proper graph reference is
present, it does not allow the caller to distinguish between a
yet-to-be-probed panel or bridge and the absence of a reference to a
panel.
One such case is a DisplayPort controller that on some boards have an
explicitly described reference to a panel, but on others have a
discoverable DisplayPort display attached (which doesn't need to be
expressed in DeviceTree).
This reverts commit '67bae5f28c89 ("drm: of: Properly try all possible
cases for bridge/panel detection")', as a step towards reverting commit
'80253168dbfd ("drm: of: Lookup if child node has panel or bridge")'.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220420231230.58499-1-bjorn.andersson@linaro.org
While bridge/panel detection was initially relying on the usual
port/ports-based of graph detection, it was recently changed to
perform the lookup on any child node that is not port/ports
instead when such a node is available, with no fallback on the
usual way.
This results in breaking detection when a child node is present
but does not contain any panel or bridge node, even when the
usual port/ports-based of graph is there.
In order to support both situations properly, this commit reworks
the logic to try both options and not just one of the two: it will
only return -EPROBE_DEFER when both have failed.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Fixes: 80253168db ("drm: of: Lookup if child node has panel or bridge")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329132732.628474-1-paul.kocialkowski@bootlin.com
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.18-rc1.
Not much here, primarily it was a bunch of cleanups and small updates:
- kobj_type cleanups for default_groups
- documentation updates
- firmware loader minor changes
- component common helper added and take advantage of it in many
drivers (the largest part of this pull request).
All of these have been in linux-next for a while with no reported
problems"
* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
Documentation: update stable review cycle documentation
drivers/base/dd.c : Remove the initial value of the global variable
Documentation: update stable tree link
Documentation: add link to stable release candidate tree
devres: fix typos in comments
Documentation: add note block surrounding security patch note
samples/kobject: Use sysfs_emit instead of sprintf
base: soc: Make soc_device_match() simpler and easier to read
driver core: dd: fix return value of __setup handler
driver core: Refactor sysfs and drv/bus remove hooks
driver core: Refactor multiple copies of device cleanup
scripts: get_abi.pl: Fix typo in help message
kernfs: fix typos in comments
kernfs: remove unneeded #if 0 guard
ALSA: hda/realtek: Make use of the helper component_compare_dev_name
video: omapfb: dss: Make use of the helper component_compare_dev
power: supply: ab8500: Make use of the helper component_compare_dev
ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
iommu/mediatek: Make use of the helper component_compare/release_of
drm: of: Make use of the helper component_release_of
...
Devices can also be child nodes when we also control that device
through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
drm_of_find_panel_or_bridge can lookup panel or bridge for a given
device has port and endpoint and it fails to lookup if the device
has a child nodes.
This patch add support to lookup for a child node of the given parent
that isn't either port or ports.
Example OF graph representation of DSI host, which has port but
not has ports and has child panel node.
dsi {
compatible = "allwinner,sun6i-a31-mipi-dsi";
#address-cells = <1>;
#size-cells = <0>;
port {
dsi_in_tcon0: endpoint {
remote-endpoint = <tcon0_out_dsi>;
};
panel@0 {
reg = <0>;
};
};
Example OF graph representation of DSI host, which has ports but
not has port and has child panel node.
dsi {
compatible = "samsung,exynos5433-mipi-dsi";
#address-cells = <1>;
#size-cells = <0>;
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
dsi_to_mic: endpoint {
remote-endpoint = <&mic_to_dsi>;
};
};
};
panel@0 {
reg = <0>;
};
};
Example OF graph representation of DSI host, which has neither a port
nor a ports but has child panel node.
dsi0 {
compatible = "ste,mcde-dsi";
#address-cells = <1>;
#size-cells = <0>;
panel@0 {
reg = <0>;
};
};
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202160414.16493-1-jagan@amarulasolutions.com
Display drivers so far need to have a lot of boilerplate to first
retrieve either the panel or bridge that they are connected to using
drm_of_find_panel_or_bridge(), and then either deal with each with ad-hoc
functions or create a drm panel bridge through drm_panel_bridge_add.
In order to reduce the boilerplate and hopefully create a path of least
resistance towards using the DRM panel bridge layer, let's create the
function devm_drm_of_get_bridge() to reduce that boilerplate.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210910130941.1740182-2-maxime@cerno.tech
When graph isn't defined in a device-tree, the of_graph_get_remote_node()
prints a noisy error message, telling that port node is not found. This is
undesirable behaviour in our case because absence of a panel/bridge graph
is a valid case. Let's check the graph's presence in a device-tree before
proceeding with parsing of the graph.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701074232.13632-3-digetx@gmail.com
An LVDS dual-link connection is made of two links, with even
pixels transitting on one link, and odd pixels on the other
link. The device tree can be used to fully describe dual-link
LVDS connections between encoders and bridges/panels.
The sink of an LVDS dual-link connection is made of two ports,
the corresponding OF graph port nodes can be marked
with either dual-lvds-even-pixels or dual-lvds-odd-pixels,
and that fully describes an LVDS dual-link connection,
including pixel order.
drm_of_lvds_get_dual_link_pixel_order is a new helper
added by this patch, given the source port nodes it
returns DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS if the source
port nodes belong to an LVDS dual-link connection, with even
pixels expected to be generated from the first port, and odd
pixels expected to be generated from the second port.
If the new helper returns DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS,
odd pixels are expected to be generated from the first port,
and even pixels from the other port.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
