Add bindings for the GE SUNH add-on connector. This is a physical,
hot-pluggable connector that allows to attach and detach at runtime an
add-on adding peripherals on non-discoverable busses.
Signed-off-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
---
NOTE: the second and third examples fail 'make dt_binding_check' because
they are example of DT overlay code -- I'm not aware of a way to
validate overlay examples as of now
This patch is new in v2.
---
.../connector/ge,sunh-addon-connector.yaml | 197 +++++++++++++++++++++
MAINTAINERS | 5 +
2 files changed, 202 insertions(+)
diff --git a/Documentation/devicetree/bindings/connector/ge,sunh-addon-connector.yaml b/Documentation/devicetree/bindings/connector/ge,sunh-addon-connector.yaml
new file mode 100644
index 000000000000..c7ac62e5f2c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/connector/ge,sunh-addon-connector.yaml
@@ -0,0 +1,197 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/connector/ge,sunh-addon-connector.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GE SUNH hotplug add-on connector
+
+maintainers:
+ - Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
+
+description:
+ Represent the physical connector present on GE SUNH devices that allows
+ to attach and detach at runtime an add-on adding peripherals on
+ non-discoverable busses.
+
+ This connector has status GPIOs to notify the connection status to the
+ CPU and a reset GPIO to allow the CPU to reset all the peripherals on the
+ add-on. It also has a 4-lane MIPI DSI bus.
+
+ Add-on removal can happen at any moment under user control and without
+ prior notice to the CPU, making all of its components not usable
+ anymore. Later on, the same or a different add-on model can be connected.
+
+properties:
+ compatible:
+ const: ge,sunh-addon-connector
+
+ reset-gpios:
+ description: An output GPIO to reset the peripherals on the add-on.
+ maxItems: 1
+
+ plugged-gpios:
+ description: An input GPIO that is asserted if and only if an add-on is
+ physically connected.
+ maxItems: 1
+
+ powergood-gpios:
+ description: An input GPIO that is asserted if and only if power rails
+ on the add-on are stable.
+ maxItems: 1
+
+ ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+
+ description: OF graph bindings modeling the MIPI DSI bus across the
+ connector. The connector splits the video pipeline in a fixed part
+ and a removable part.
+
+ The fixed part of the video pipeline includes all components up to
+ the display controller and 0 or more bridges. The removable part
+ includes any bridges and any other components up to the panel.
+
+ properties:
+ port@0:
+ $ref: /schemas/graph.yaml#/properties/port
+ description: The MIPI DSI bus line from the CPU to the connector.
+ The remote-endpoint sub-node must point to the last non-removable
+ component of the video pipeline.
+
+ port@1:
+ $ref: /schemas/graph.yaml#/properties/port
+
+ description: The MIPI DSI bus line from the connector to the
+ add-on. The remote-endpoint sub-node must point to the first
+ add-on component of the video pipeline. As it describes the
+ hot-pluggable hardware, the endpoint node cannot be filled until
+ an add-on is detected, so this needs to be done by a device tree
+ overlay at runtime.
+
+ required:
+ - port@0
+ - port@1
+
+required:
+ - compatible
+
+unevaluatedProperties: false
+
+examples:
+ # Main DTS describing the "main" board up to the connector
+ - |
+ / {
+ #include <dt-bindings/gpio/gpio.h>
+
+ addon_connector: addon-connector {
+ compatible = "ge,sunh-addon-connector";
+ reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+ plugged-gpios = <&gpio1 2 GPIO_ACTIVE_LOW>;
+ powergood-gpios = <&gpio1 3 GPIO_ACTIVE_HIGH>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ hotplug_conn_dsi_in: endpoint {
+ remote-endpoint = <&previous_bridge_out>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ hotplug_conn_dsi_out: endpoint {
+ // remote-endpoint to be added by overlay
+ };
+ };
+ };
+ };
+ };
+
+ # "base" overlay describing the common components on every add-on that
+ # are required to read the model ID
+ - |
+ &i2c1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ eeprom@50 {
+ compatible = "atmel,24c64";
+ reg = <0x50>;
+
+ nvmem-layout {
+ compatible = "fixed-layout";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ addon_model_id: addon-model-id@400 {
+ reg = <0x400 0x1>;
+ };
+ };
+ };
+ };
+
+ &addon_connector {
+ nvmem-cells = <&addon_model_id>;
+ nvmem-cell-names = "id";
+ };
+
+ # Add-on-specific overlay describing all add-on components not in the
+ # "base" overlay
+ - |
+ &hotplug_conn_dsi_out {
+ remote-endpoint = <&addon_bridge_in>;
+ };
+
+ &i2c1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ dsi-lvds-bridge@42 {
+ compatible = "some-video-bridge";
+ reg = <0x42>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ addon_bridge_in: endpoint {
+ remote-endpoint = <&hotplug_conn_dsi_out>;
+ data-lanes = <1 2 3 4>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ addon_bridge_out: endpoint {
+ remote-endpoint = <&panel_in>;
+ };
+ };
+ };
+ };
+ };
+
+ &{/}
+ {
+ panel {
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0{
+ reg = <0>;
+
+ panel_in: endpoint {
+ remote-endpoint = <&addon_bridge_out>;
+ };
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index ec0284125e8f..4955501217eb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9897,6 +9897,11 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/pressure/honeywell,mprls0025pa.yaml
F: drivers/iio/pressure/mprls0025pa*
+HOTPLUG CONNECTOR FOR GE SUNH ADDONS
+M: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/connector/ge,sunh-addon-connector.yaml
+
HP BIOSCFG DRIVER
M: Jorge Lopez <jorge.lopez2@xxxxxx>
L: platform-driver-x86@xxxxxxxxxxxxxxx
--
2.34.1
