MX8 Display: Difference between revisions

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(Fix DTB_PREFIX_SP8)
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{{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX8|
{{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX8|
{{#varexists:DTB_PREFIX | | {{#vardefine:DTB_PREFIX|fsl-imx8qm-var-som}} }}
{{#varexists:DTB_PREFIX_SP8 | | {{#vardefine:DTB_PREFIX_SP8|fsl-imx8qm-var-spear}} }}
<!-- Create device trees for QP -->
{{#vardefine:DTB_PREFIX_QP|{{#replace:{{#var:DTB_PREFIX}}|imx8qm|imx8qp}}}}
{{#vardefine:DTB_PREFIX_SP8_QP|{{#replace:{{#var:DTB_PREFIX_SP8}}|imx8qm|imx8qp}}}}


= Selecting display type =
= Selecting display type =
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  # cd /boot
  # cd /boot
  # ln -fs fsl-imx8qm-var-som-hdmi.dtb fsl-imx8qm-var-som.dtb
  # ln -fs {{#var:DTB_PREFIX}}-hdmi.dtb {{#var:DTB_PREFIX}}.dtb
# ln -fs {{#var:DTB_PREFIX_QP}}-hdmi.dtb {{#var:DTB_PREFIX_QP}}.dtb (For i.MX8QP SoC)


To select DP display, run the following commands:
To select DP display, run the following commands:


  # cd /boot
  # cd /boot
  # ln -fs fsl-imx8qm-var-som-dp.dtb fsl-imx8qm-var-som.dtb
  # ln -fs {{#var:DTB_PREFIX}}-dp.dtb {{#var:DTB_PREFIX}}.dtb
# ln -fs {{#var:DTB_PREFIX_QP}}-dp.dtb {{#var:DTB_PREFIX_QP}}.dtb (For i.MX8QP SoC)


On SPEAR-MX8 /boot/fsl-imx8qm-var-spear.dtb is a symbolic link to the active dtb file. By default it points to LVDS dtb.<br>
On SPEAR-MX8 /boot/fsl-imx8qm-var-spear.dtb is a symbolic link to the active dtb file. By default it points to LVDS dtb.<br>
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  # cd /boot
  # cd /boot
  # ln -fs fsl-imx8qm-var-spear-hdmi.dtb fsl-imx8qm-var-spear.dtb
  # ln -fs {{#var:DTB_PREFIX_SP8}}-hdmi.dtb {{#var:DTB_PREFIX_SP8}}.dtb
# ln -fs {{#var:DTB_PREFIX_SP8_QP}}-hdmi.dtb {{#var:DTB_PREFIX_SP8_QP}}.dtb (For i.MX8QP SoC)


To select DP display, run the following commands:
To select DP display, run the following commands:


  # cd /boot
  # cd /boot
  # ln -fs fsl-imx8qm-var-spear-dp.dtb fsl-imx8qm-var-spear.dtb
  # ln -fs {{#var:DTB_PREFIX_SP8}}-dp.dtb {{#var:DTB_PREFIX_SP8}}.dtb
# ln -fs {{#var:DTB_PREFIX_SP8_QP}}-dp.dtb {{#var:DTB_PREFIX_SP8_QP}}.dtb (For i.MX8QP SoC)


The change will be effective after reboot.<br>
The change will be effective after reboot.<br>
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The default Weston uses maximum resolution supported by display.<br>
The default Weston uses maximum resolution supported by display.<br>
To modify Weston resolution, edit /etc/xdg/weston/weston.ini and set size parameter in shell section.<br>
To modify Weston resolution, edit /etc/xdg/weston/weston.ini and set size parameter in shell section.<br>
For example, to set 1080P resolution
For example:


  [shell]
  [shell]

Revision as of 17:29, 25 October 2022

VAR-SOM-MX8X Display


LVDS

VAR-SOM-MX8X supports one dual-channel LVDS interface.
VAR-SOM-MX8X evaluation kit comes with two LVDS connectors, one connector per LVDS channel.
By default Variscite panel is attached to LVDS#A connector.

Adding custom LVDS panel

VAR-SOM-MX8X evaluation kit comes with 800x480 LVDS panel.
VAR-SOM-MX8X DTS file was created with this panel in mind.
To support different LVDS panel, several modifications may be required.

The following code configures LVDS panel in arch/arm64/boot/dts/freescale/fsl-imx8qxp-var-som-common.dtsi under kernel source tree:

&ldb1_phy {
	status = "ok";
};

&ldb1 {
	status = "ok";
	lvds-channel@0 {
		fsl,data-mapping = "jeida";
		fsl,data-width = <24>;
		status = "ok";

		display-timings {
			lvds {
				clock-frequency = <29232000>;
				hactive = <800>;
				vactive = <480>;
				hback-porch = <40>;
				hfront-porch = <40>;
				vback-porch = <29>;
				vfront-porch = <13>;
				hsync-len = <48>;
				vsync-len = <3>;
				hsync-active = <0>;
				vsync-active = <0>;
				de-active = <1>;
				pixelclk-active = <0>;
			};
		};
	};
};

You may need to modify "fsl,data-mapping", "fsl,data-width" and "display-timings" properties to match your panel specification.
For more information see Documentation/devicetree/bindings/display/imx/ldb.txt in the kernel source tree.

Setting Weston Desktop Resolution

The default Weston uses maximum resolution supported by display.
To modify Weston resolution, edit /etc/xdg/weston/weston.ini and set size parameter in shell section.
For example:

[shell]
size=3840x2160

For new settings to take effect restart weston by running

# systemctl restart weston