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Subject[PATCH 0/4] drm+dt: multi panel selection and yoga c630 display
From: Rob Clark <>

It is not uncommon for devices to use one of several possible panels.
The Lenovo Yoga C630 laptop is one such device. This patchset
introduces an optional "panel-id" property which can be used by the
firmware to find the correct panel node to enable. The second patch
adds support in drm/of to automatically pick the enabled endpoint, to
avoid adding the same logic in multiple bridges/drivers. The last
patch uses this mechanism to enable display support for the Yoga C630.

An example usage:

boe_panel {
compatible = "boe,nv133fhm-n61";
panel-id = <0xc4>;
/* fw will change status to "Ok" if this panel is installed */
status = "disabled";

ports {
port {
boe_panel_in_edp: endpoint {
remote-endpoint = <&sn65dsi86_out_boe>;

ivo_panel {
compatible = "ivo,m133nwf4-r0";
panel-id = <0xc5>;
/* fw will change status to "Ok" if this panel is installed */
status = "disabled";

ports {
port {
ivo_panel_in_edp: endpoint {
remote-endpoint = <&sn65dsi86_out_ivo>;

sn65dsi86: bridge@2c {
compatible = "ti,sn65dsi86";

ports {
#address-cells = <1>;
#size-cells = <0>;

port@0 {
reg = <0>;
sn65dsi86_in_a: endpoint {
remote-endpoint = <&dsi0_out>;

port@1 {
reg = <1>;

sn65dsi86_out_boe: endpoint@c4 {
remote-endpoint = <&boe_panel_in_edp>;

sn65dsi86_out_ivo: endpoint@c5 {
remote-endpoint = <&ivo_panel_in_edp>;

This replaces an earlier proposal[1] to use chosen/panel-id to select the
installed panel, in favor of adding support[2] to an EFI driver module
(DtbLoader.efi) to find the installed panel, locate it in dtb via the
'panel-id' property, and update it's status to "Ok".


In this case, DtbLoader, which is somewhat generic (ie. this mechanism
applies to all snapdragon based devices which orignally ship with
windows), determines the panel-id of the installed panel from the
UEFIDisplayInfo variable.

As I understand, a similar situation exists with the pine64 laptops. A
similar scheme could be used to support this, by loading the panel-id
from a u-boot variable.

In other cases (phones), a more device specific shim would be needed to
determine the panel-id by reading some GPIOs, or some other more device-
specific mechanism.

Bjorn Andersson (1):
arm64: dts: qcom: c630: Enable display

Rob Clark (3):
dt-bindings: display: panel: document panel-id
drm/of: add support to find any enabled endpoint
drm/bridge: ti-sn65dsi86: find any enabled endpoint

.../bindings/display/panel/panel-common.yaml | 26 +++
.../boot/dts/qcom/sdm850-lenovo-yoga-c630.dts | 165 ++++++++++++++++++
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 2 +-
drivers/gpu/drm/drm_of.c | 41 ++++-
4 files changed, 232 insertions(+), 2 deletions(-)


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