Re: [PATCH v2 1/3] dt-bindings: display: convert Atmel's HLCDC to DT schema

From: Dharma.B
Date: Tue Jan 16 2024 - 21:36:20 EST

On 16/01/24 11:25 pm, Conor Dooley wrote:
> Yo,
>
> On Tue, Jan 16, 2024 at 05:07:58PM +0530, Dharma Balasubiramani wrote:
>> Convert the existing DT binding to DT schema of the Atmel's HLCDC display
>> controller.
>>
>> Signed-off-by: Dharma Balasubiramani<dharma.b@xxxxxxxxxxxxx>
>> ---
>> changelog
>> v1 -> v2
>> - Remove the explicit copyrights.
>> - Modify filename like compatible.
>> - Modify title (drop words like binding/driver).
>> - Modify description actually describing the hardware and not the driver.
>> - Remove pinctrl properties which aren't required.
>> - Ref endpoint and not endpoint-base.
>> - Drop redundant info about bus-width description and add ref to video-interfaces.
>> - Move 'additionalProperties' after 'Required'.
>> - Drop parent node and it's other sub-device node which are not related here.
>> - Add compatible to example 2 and add comments that bus-width is the diff between two examples.
>> ---
>> .../atmel/atmel,hlcdc-display-controller.yaml | 110 ++++++++++++++++++
>> .../bindings/display/atmel/hlcdc-dc.txt | 75 ------------
>> 2 files changed, 110 insertions(+), 75 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
>> delete mode 100644 Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>>
>> diff --git a/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml b/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
>> new file mode 100644
>> index 000000000000..f022c294cfbc
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
>> @@ -0,0 +1,110 @@
>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id:http://devicetree.org/schemas/display/atmel/atmel,hlcdc-display-controller.yaml#
>> +$schema:http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Atmel's High LCD Controller (HLCDC)
>> +
>> +maintainers:
>> + - Nicolas Ferre<nicolas.ferre@xxxxxxxxxxxxx>
>> + - Alexandre Belloni<alexandre.belloni@xxxxxxxxxxx>
>> + - Claudiu Beznea<claudiu.beznea@xxxxxxxxx>
>> +
>> +description: |
> This | is not needed as you have no formatting to preserve.
Sure, I will drop this '|'.
>
>> + The LCD Controller (LCDC) consists of logic for transferring LCD image
>> + data from an external display buffer to a TFT LCD panel. The LCDC has one
>> + display input buffer per layer that fetches pixels through the single bus
>> + host interface and a look-up table to allow palletized display
>> + configurations.
>> +
>> +properties:
>> + compatible:
>> + const: atmel,hlcdc-display-controller
>> +
>> + '#address-cells':
>> + const: 1
>> +
>> + '#size-cells':
>> + const: 0
>> +
>> + port@0:
>> + $ref: /schemas/graph.yaml#/$defs/port-base
>> + unevaluatedProperties: false
>> + description:
>> + Output endpoint of the controller, connecting the LCD panel signals.
>> +
>> + properties:
>> + '#address-cells':
>> + const: 1
>> +
>> + '#size-cells':
>> + const: 0
>> +
>> + reg:
>> + maxItems: 1
>> +
>> + endpoint:
>> + $ref: /schemas/graph.yaml#/$defs/endpoint
> $ref: /schemas/media/video-interfaces.yaml#
I will replace this.
>
> to match approximately all other endpoints?
I'm not sure; some of the referenced devices, like this one, were
pointing to 'endpoint.' I will go with 'video-interfaces.'
>
>> + unevaluatedProperties: false
>> + description:
>> + Endpoint connecting the LCD panel signals.
>> +
>> + properties:
>> + bus-width:
>> + description: Endpoint bus width.
>> + $ref: /schemas/media/video-interfaces.yaml#
> and then bus-width's type is already defined for you, no?
I will remove this $ref here.
>
>> + enum: [ 12, 16, 18, 24 ]
>> +
>> +required:
>> + - '#address-cells'
>> + - '#size-cells'
>> + - compatible
>> + - port@0
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> + - |
>> + //Example 1
>> +
>> + display-controller {
>> + compatible = "atmel,hlcdc-display-controller";
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + port@0 {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + reg = <0>;
>> +
>> + hlcdc_panel_output: endpoint@0 {
>> + reg = <0>;
>> + remote-endpoint = <&panel_input>;
>> + };
>> + };
>> + };
>> +
>> + - |
>> + //Example 2 With a video interface override to force rgb565, bus-width=16
>> +
>> + display-controller {
>> + compatible = "atmel,hlcdc-display-controller";
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + port@0 {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + reg = <0>;
> Should be a newline here before the child node.
Sure, I will take care of this in v3.

--
With Best Regards,
Dharma B.
>
> Cheers,
> Conor.
>
>> + hlcdc_panel_output2: endpoint@0 {
>> + reg = <0>;
>> + remote-endpoint = <&panel_input>;
>> + bus-width = <16>;
>> + };
>> + };
>> + };
>> diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>> deleted file mode 100644
>> index 923aea25344c..000000000000
>> --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>> +++ /dev/null
>> @@ -1,75 +0,0 @@
>> -Device-Tree bindings for Atmel's HLCDC (High LCD Controller) DRM driver
>> -
>> -The Atmel HLCDC Display Controller is subdevice of the HLCDC MFD device.
>> -See ../../mfd/atmel-hlcdc.txt for more details.
>> -
>> -Required properties:
>> - - compatible: value should be "atmel,hlcdc-display-controller"
>> - - pinctrl-names: the pin control state names. Should contain "default".
>> - - pinctrl-0: should contain the default pinctrl states.
>> - - #address-cells: should be set to 1.
>> - - #size-cells: should be set to 0.
>> -
>> -Required children nodes:
>> - Children nodes are encoding available output ports and their connections
>> - to external devices using the OF graph representation (see ../graph.txt).
>> - At least one port node is required.
>> -
>> -Optional properties in grandchild nodes:
>> - Any endpoint grandchild node may specify a desired video interface
>> - according to ../../media/video-interfaces.txt, specifically
>> - - bus-width: recognized values are <12>, <16>, <18> and <24>, and
>> - override any output mode selection heuristic, forcing "rgb444",
>> - "rgb565", "rgb666" and "rgb888" respectively.
>> -
>> -Example:
>> -
>> - hlcdc: hlcdc@f0030000 {
>> - compatible = "atmel,sama5d3-hlcdc";
>> - reg = <0xf0030000 0x2000>;
>> - interrupts = <36 IRQ_TYPE_LEVEL_HIGH 0>;
>> - clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
>> - clock-names = "periph_clk","sys_clk", "slow_clk";
>> -
>> - hlcdc-display-controller {
>> - compatible = "atmel,hlcdc-display-controller";
>> - pinctrl-names = "default";
>> - pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
>> - #address-cells = <1>;
>> - #size-cells = <0>;
>> -
>> - port@0 {
>> - #address-cells = <1>;
>> - #size-cells = <0>;
>> - reg = <0>;
>> -
>> - hlcdc_panel_output: endpoint@0 {
>> - reg = <0>;
>> - remote-endpoint = <&panel_input>;
>> - };
>> - };
>> - };
>> -
>> - hlcdc_pwm: hlcdc-pwm {
>> - compatible = "atmel,hlcdc-pwm";
>> - pinctrl-names = "default";
>> - pinctrl-0 = <&pinctrl_lcd_pwm>;
>> - #pwm-cells = <3>;
>> - };
>> - };
>> -
>> -Example 2: With a video interface override to force rgb565; as above
>> -but with these changes/additions:
>> -
>> - &hlcdc {
>> - hlcdc-display-controller {
>> - pinctrl-names = "default";
>> - pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
>> -
>> - port@0 {
>> - hlcdc_panel_output: endpoint@0 {
>> - bus-width = <16>;
>> - };
>> - };
>> - };
>> - };
>> --
>> 2.25.1
>>