[RFC PATCH 1/4] dt-bindings: display: Convert common panel bindings to DT schema

Rob Herring
2019-06-19T21:51:53Z

Convert the common panel bindings to DT schema consolidating scattered
definitions to a single schema file.

The 'simple-panel' binding just a collection of properties and not a
complete binding itself. All of the 'simple-panel' properties are
covered by the panel-common.txt binding with the exception of the
'no-hpd' property, so add that to the schema.

As there are lots of references to simple-panel.txt, just keep the file
with a reference to panel-common.yaml for now until all the bindings are
converted.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Rob Herring <robh@kernel.org>
---
Note there's still some references to panel-common.txt that I need to
update or just go ahead and convert to schema.

.../bindings/display/panel/panel-common.txt | 101 -------------
.../bindings/display/panel/panel-common.yaml | 143 ++++++++++++++++++
.../bindings/display/panel/panel.txt | 4 -
.../bindings/display/panel/simple-panel.txt | 29 +---
4 files changed, 144 insertions(+), 133 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/display/panel/panel-common.txt
create mode 100644 Documentation/devicetree/bindings/display/panel/panel-common.yaml
delete mode 100644 Documentation/devicetree/bindings/display/panel/panel.txt

diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.txt b/Documentation/devicetree/bindings/display/panel/panel-common.txt
deleted file mode 100644
index 5d2519af4bb5..000000000000
--- a/Documentation/devicetree/bindings/display/panel/panel-common.txt
+++ /dev/null
@@ -1,101 +0,0 @@
-Common Properties for Display Panel
-===================================
-
-This document defines device tree properties common to several classes of
-display panels. It doesn't constitue a device tree binding specification by
-itself but is meant to be referenced by device tree bindings.
-
-When referenced from panel device tree bindings the properties defined in this
-document are defined as follows. The panel device tree bindings are
-responsible for defining whether each property is required or optional.
-
-
-Descriptive Properties
-----------------------
-
-- width-mm,
-- height-mm: The width-mm and height-mm specify the width and height of the
- physical area where images are displayed. These properties are expressed in
- millimeters and rounded to the closest unit.
-
-- label: The label property specifies a symbolic name for the panel as a
- string suitable for use by humans. It typically contains a name inscribed on
- the system (e.g. as an affixed label) or specified in the system's
- documentation (e.g. in the user's manual).
-
- If no such name exists, and unless the property is mandatory according to
- device tree bindings, it shall rather be omitted than constructed of
- non-descriptive information. For instance an LCD panel in a system that
- contains a single panel shall not be labelled "LCD" if that name is not
- inscribed on the system or used in a descriptive fashion in system
- documentation.
-
-
-Display Timings
----------------
-
-- panel-timing: Most display panels are restricted to a single resolution and
- require specific display timings. The panel-timing subnode expresses those
- timings as specified in the timing subnode section of the display timing
- bindings defined in
- Documentation/devicetree/bindings/display/panel/display-timing.txt.
-
-
-Connectivity
-------------
-
-- ports: Panels receive video data through one or multiple connections. While
- the nature of those connections is specific to the panel type, the
- connectivity is expressed in a standard fashion using ports as specified in
- the device graph bindings defined in
- Documentation/devicetree/bindings/graph.txt.
-
-- ddc-i2c-bus: Some panels expose EDID information through an I2C-compatible
- bus such as DDC2 or E-DDC. For such panels the ddc-i2c-bus contains a
- phandle to the system I2C controller connected to that bus.
-
-
-Control I/Os
-------------
-
-Many display panels can be controlled through pins driven by GPIOs. The nature
-and timing of those control signals are device-specific and left for panel
-device tree bindings to specify. The following GPIO specifiers can however be
-used for panels that implement compatible control signals.
-
-- enable-gpios: Specifier for a GPIO connected to the panel enable control
- signal. The enable signal is active high and enables operation of the panel.
- This property can also be used for panels implementing an active low power
- down signal, which is a negated version of the enable signal. Active low
- enable signals (or active high power down signals) can be supported by
- inverting the GPIO specifier polarity flag.
-
- Note that the enable signal control panel operation only and must not be
- confused with a backlight enable signal.
-
-- reset-gpios: Specifier for a GPIO coonnected to the panel reset control
- signal. The reset signal is active low and resets the panel internal logic
- while active. Active high reset signals can be supported by inverting the
- GPIO specifier polarity flag.
-
-Power
------
-
-- power-supply: display panels require power to be supplied. While several
- panels need more than one power supply with panel-specific constraints
- governing the order and timings of the power supplies, in many cases a single
- power supply is sufficient, either because the panel has a single power rail,
- or because all its power rails can be driven by the same supply. In that case
- the power-supply property specifies the supply powering the panel as a phandle
- to a regulator.
-
-Backlight
----------
-
-Most display panels include a backlight. Some of them also include a backlight
-controller exposed through a control bus such as I2C or DSI. Others expose
-backlight control through GPIO, PWM or other signals connected to an external
-backlight controller.
-
-- backlight: For panels whose backlight is controlled by an external backlight
- controller, this property contains a phandle that references the controller.
diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
new file mode 100644
index 000000000000..6fe87254edad
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
@@ -0,0 +1,143 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/panel-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Properties for Display Panels
+
+maintainers:
+ - Thierry Reding <thierry.reding@gmail.com>
+ - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
+
+description: |
+ This document defines device tree properties common to several classes of
+ display panels. It doesn't constitue a device tree binding specification by
+ itself but is meant to be referenced by device tree bindings.
+
+ When referenced from panel device tree bindings the properties defined in this
+ document are defined as follows. The panel device tree bindings are
+ responsible for defining whether each property is required or optional.
+
+
+properties:
+ # Descriptive Properties
+ width-mm:
+ description: The width-mm and height-mm specify the width and height of the
+ physical area where images are displayed. These properties are expressed
+ in millimeters and rounded to the closest unit.
+
+ height-mm:
+ description: The width-mm and height-mm specify the width and height of the
+ physical area where images are displayed. These properties are expressed
+ in millimeters and rounded to the closest unit.
+
+ label:
+ description: |
+ The label property specifies a symbolic name for the panel as a
+ string suitable for use by humans. It typically contains a name inscribed
+ on the system (e.g. as an affixed label) or specified in the system's
+ documentation (e.g. in the user's manual).
+
+ If no such name exists, and unless the property is mandatory according to
+ device tree bindings, it shall rather be omitted than constructed of
+ non-descriptive information. For instance an LCD panel in a system that
+ contains a single panel shall not be labelled "LCD" if that name is not
+ inscribed on the system or used in a descriptive fashion in system
+ documentation.
+
+ rotation:
+ description:
+ Display rotation in degrees counter clockwise (0,90,180,270)
+ allOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32
+ - enum: [ 0, 90, 180, 270 ]
+
+ # Display Timings
+ panel-timing:
+ type: object
+ description:
+ Most display panels are restricted to a single resolution and
+ require specific display timings. The panel-timing subnode expresses those
+ timings as specified in the timing subnode section of the display timing
+ bindings defined in
+ Documentation/devicetree/bindings/display/panel/display-timing.txt.
+
+ # Connectivity
+ ports:
+ type: object
+ description:
+ Panels receive video data through one or multiple connections. While
+ the nature of those connections is specific to the panel type, the
+ connectivity is expressed in a standard fashion using ports as specified
+ in the device graph bindings defined in
+ Documentation/devicetree/bindings/graph.txt.
+
+ ddc-i2c-bus:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Some panels expose EDID information through an I2C-compatible
+ bus such as DDC2 or E-DDC. For such panels the ddc-i2c-bus contains a
+ phandle to the system I2C controller connected to that bus.
+
+ no-hpd:
+ type: boolean
+ description:
+ This panel is supposed to communicate that it's ready via HPD
+ (hot plug detect) signal, but the signal isn't hooked up so we should
+ hardcode the max delay from the panel spec when powering up the panel.
+
+ # Control I/Os
+
+ # Many display panels can be controlled through pins driven by GPIOs. The nature
+ # and timing of those control signals are device-specific and left for panel
+ # device tree bindings to specify. The following GPIO specifiers can however be
+ # used for panels that implement compatible control signals.
+
+ enable-gpios:
+ maxItems: 1
+ description: |
+ Specifier for a GPIO connected to the panel enable control signal. The
+ enable signal is active high and enables operation of the panel. This
+ property can also be used for panels implementing an active low power down
+ signal, which is a negated version of the enable signal. Active low enable
+ signals (or active high power down signals) can be supported by inverting
+ the GPIO specifier polarity flag.
+
+ Note that the enable signal control panel operation only and must not be
+ confused with a backlight enable signal.
+
+ reset-gpios:
+ maxItems: 1
+ description:
+ Specifier for a GPIO coonnected to the panel reset control signal.
+ The reset signal is active low and resets the panel internal logic
+ while active. Active high reset signals can be supported by inverting the
+ GPIO specifier polarity flag.
+
+ # Power
+ power-supply:
+ description:
+ Display panels require power to be supplied. While several panels need
+ more than one power supply with panel-specific constraints governing the
+ order and timings of the power supplies, in many cases a single power
+ supply is sufficient, either because the panel has a single power rail, or
+ because all its power rails can be driven by the same supply. In that case
+ the power-supply property specifies the supply powering the panel as a
+ phandle to a regulator.
+
+ # Backlight
+
+ # Most display panels include a backlight. Some of them also include a backlight
+ # controller exposed through a control bus such as I2C or DSI. Others expose
+ # backlight control through GPIO, PWM or other signals connected to an external
+ # backlight controller.
+
+ backlight:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ For panels whose backlight is controlled by an external backlight
+ controller, this property contains a phandle that references the
+ controller.
+
+...
diff --git a/Documentation/devicetree/bindings/display/panel/panel.txt b/Documentation/devicetree/bindings/display/panel/panel.txt
deleted file mode 100644
index e2e6867852b8..000000000000
--- a/Documentation/devicetree/bindings/display/panel/panel.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-Common display properties
--------------------------
-
-- rotation: Display rotation in degrees counter clockwise (0,90,180,270)
diff --git a/Documentation/devicetree/bindings/display/panel/simple-panel.txt b/Documentation/devicetree/bindings/display/panel/simple-panel.txt
index b2b872c710f2..e11208fb7da8 100644
--- a/Documentation/devicetree/bindings/display/panel/simple-panel.txt
+++ b/Documentation/devicetree/bindings/display/panel/simple-panel.txt
@@ -1,28 +1 @@
-Simple display panel
-====================
-
-panel node
-----------
-
-Required properties:
-- power-supply: See panel-common.txt
-
-Optional properties:
-- ddc-i2c-bus: phandle of an I2C controller used for DDC EDID probing
-- enable-gpios: GPIO pin to enable or disable the panel
-- backlight: phandle of the backlight device attached to the panel
-- no-hpd: This panel is supposed to communicate that it's ready via HPD
- (hot plug detect) signal, but the signal isn't hooked up so we should
- hardcode the max delay from the panel spec when powering up the panel.
-
-Example:
-
- panel: panel {
- compatible = "cptt,claa101wb01";
- ddc-i2c-bus = <&panelddc>;
-
- power-supply = <&vdd_pnl_reg>;
- enable-gpios = <&gpio 90 0>;
-
- backlight = <&backlight>;
- };
+See panel-common.yaml in this directory.
--
2.20.1