[PATCH v3 2/5] dt-bindings: display: convert display-timings to DT schema
Sam Ravnborg
sam at ravnborg.org
Sun Feb 16 18:15:10 UTC 2020
Add display-timings.yaml - that references panel-timings.yaml.
display-timings.yaml will be used for display bindings
when they are converted to meta-schema format.
For now the old display-timing.txt points to the new
display-timings.yaml - and all users are left as-is.
v2:
- Updated native-mode description
v3:
- Simpler "^timing" pattern (Rob)
- timing node is of type object (Rob)
- added display-timings to panel-common.yaml
- added yaml document terminator "..."
Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
Reviewed-by: Rob Herring <robh at kernel.org>
Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Oleksandr Suvorov <oleksandr.suvorov at toradex.com>
Cc: devicetree at vger.kernel.org
---
.../bindings/display/panel/display-timing.txt | 124 +-----------------
.../display/panel/display-timings.yaml | 77 +++++++++++
.../bindings/display/panel/panel-common.yaml | 8 ++
3 files changed, 86 insertions(+), 123 deletions(-)
create mode 100644 Documentation/devicetree/bindings/display/panel/display-timings.yaml
diff --git a/Documentation/devicetree/bindings/display/panel/display-timing.txt b/Documentation/devicetree/bindings/display/panel/display-timing.txt
index 78222ced1874..7f55ad4a40c4 100644
--- a/Documentation/devicetree/bindings/display/panel/display-timing.txt
+++ b/Documentation/devicetree/bindings/display/panel/display-timing.txt
@@ -1,123 +1 @@
-display-timing bindings
-=======================
-
-display-timings node
---------------------
-
-required properties:
- - none
-
-optional properties:
- - native-mode: The native mode for the display, in case multiple modes are
- provided. When omitted, assume the first node is the native.
-
-timing subnode
---------------
-
-required properties:
- - hactive, vactive: display resolution
- - hfront-porch, hback-porch, hsync-len: horizontal display timing parameters
- in pixels
- vfront-porch, vback-porch, vsync-len: vertical display timing parameters in
- lines
- - clock-frequency: display clock in Hz
-
-optional properties:
- - hsync-active: hsync pulse is active low/high/ignored
- - vsync-active: vsync pulse is active low/high/ignored
- - de-active: data-enable pulse is active low/high/ignored
- - pixelclk-active: with
- - active high = drive pixel data on rising edge/
- sample data on falling edge
- - active low = drive pixel data on falling edge/
- sample data on rising edge
- - ignored = ignored
- - syncclk-active: with
- - active high = drive sync on rising edge/
- sample sync on falling edge of pixel
- clock
- - active low = drive sync on falling edge/
- sample sync on rising edge of pixel
- clock
- - omitted = same configuration as pixelclk-active
- - interlaced (bool): boolean to enable interlaced mode
- - doublescan (bool): boolean to enable doublescan mode
- - doubleclk (bool): boolean to enable doubleclock mode
-
-All the optional properties that are not bool follow the following logic:
- <1>: high active
- <0>: low active
- omitted: not used on hardware
-
-There are different ways of describing the capabilities of a display. The
-devicetree representation corresponds to the one commonly found in datasheets
-for displays. If a display supports multiple signal timings, the native-mode
-can be specified.
-
-The parameters are defined as:
-
- +----------+-------------------------------------+----------+-------+
- | | ^ | | |
- | | |vback_porch | | |
- | | v | | |
- +----------#######################################----------+-------+
- | # ^ # | |
- | # | # | |
- | hback # | # hfront | hsync |
- | porch # | hactive # porch | len |
- |<-------->#<-------+--------------------------->#<-------->|<----->|
- | # | # | |
- | # |vactive # | |
- | # | # | |
- | # v # | |
- +----------#######################################----------+-------+
- | | ^ | | |
- | | |vfront_porch | | |
- | | v | | |
- +----------+-------------------------------------+----------+-------+
- | | ^ | | |
- | | |vsync_len | | |
- | | v | | |
- +----------+-------------------------------------+----------+-------+
-
-Note: In addition to being used as subnode(s) of display-timings, the timing
- subnode may also be used on its own. This is appropriate if only one mode
- need be conveyed. In this case, the node should be named 'panel-timing'.
-
-
-Example:
-
- display-timings {
- native-mode = <&timing0>;
- timing0: 1080p24 {
- /* 1920x1080p24 */
- clock-frequency = <52000000>;
- hactive = <1920>;
- vactive = <1080>;
- hfront-porch = <25>;
- hback-porch = <25>;
- hsync-len = <25>;
- vback-porch = <2>;
- vfront-porch = <2>;
- vsync-len = <2>;
- hsync-active = <1>;
- };
- };
-
-Every required property also supports the use of ranges, so the commonly used
-datasheet description with minimum, typical and maximum values can be used.
-
-Example:
-
- timing1: timing {
- /* 1920x1080p24 */
- clock-frequency = <148500000>;
- hactive = <1920>;
- vactive = <1080>;
- hsync-len = <0 44 60>;
- hfront-porch = <80 88 95>;
- hback-porch = <100 148 160>;
- vfront-porch = <0 4 6>;
- vback-porch = <0 36 50>;
- vsync-len = <0 5 6>;
- };
+See display-timings.yaml in this directory.
diff --git a/Documentation/devicetree/bindings/display/panel/display-timings.yaml b/Documentation/devicetree/bindings/display/panel/display-timings.yaml
new file mode 100644
index 000000000000..c8c0c9cb0492
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/display-timings.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/display-timings.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: display timing bindings
+
+maintainers:
+ - Thierry Reding <thierry.reding at gmail.com>
+ - Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
+ - Sam Ravnborg <sam at ravnborg.org>
+
+description: |
+ A display panel may be able to handle several display timings,
+ with different resolutions.
+ The display-timings node makes it possible to specify the timing
+ and to specify the timing that is native for the display.
+
+properties:
+ $nodename:
+ const: display-timings
+
+ native-mode:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: |
+ The default display timing is the one specified as native-mode.
+ If no native-mode is specified then the first node is assumed the
+ native mode.
+
+patternProperties:
+ "^timing":
+ type: object
+ allOf:
+ - $ref: panel-timing.yaml#
+
+additionalProperties: false
+
+examples:
+ - |+
+
+ /*
+ * Example that specifies panel timing using minimum, typical,
+ * maximum values as commonly used in datasheet description.
+ * timing1 is the native-mode.
+ */
+ display-timings {
+ native-mode = <&timing1>;
+ timing0 {
+ /* 1920x1080p24 */
+ clock-frequency = <148500000>;
+ hactive = <1920>;
+ vactive = <1080>;
+ hsync-len = <0 44 60>;
+ hfront-porch = <80 88 95>;
+ hback-porch = <100 148 160>;
+ vfront-porch = <0 4 6>;
+ vback-porch = <0 36 50>;
+ vsync-len = <0 5 6>;
+ };
+ timing1 {
+ /* 1920x1080p24 */
+ clock-frequency = <52000000>;
+ hactive = <1920>;
+ vactive = <1080>;
+ hfront-porch = <25>;
+ hback-porch = <25>;
+ hsync-len = <0 25 25>;
+ vback-porch = <2>;
+ vfront-porch = <2>;
+ vsync-len = <2>;
+ hsync-active = <1>;
+ pixelclk-active = <1>;
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
index 8070c439adbd..ed051ba12084 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-common.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml
@@ -61,6 +61,14 @@ properties:
allOf:
- $ref: panel-timing.yaml#
+ display-timings:
+ description:
+ Some display panels supports several resolutions with different timing.
+ The display-timings bindings supports specifying several timings and
+ optional specify which is the native mode.
+ allOf:
+ - $ref: display-timings.yaml#
+
# Connectivity
port:
type: object
--
2.20.1
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