MX8 Display: Difference between revisions
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= Selecting display type = | = Selecting display type = | ||
VAR-SOM-MX8 and SPEAR-MX8 support DP, HDMI and LVDS displays. To use DP and HDMI on VAR-SOM-MX8 carrier board one should attach Variscite extension boards VAR-EXT-DP and VAR-EXT-HDMI respectively.<br> | VAR-SOM-MX8 and SPEAR-MX8 support DP, HDMI and LVDS displays. To use DP and HDMI on VAR-SOM-MX8 carrier board one should attach Variscite extension boards VAR-EXT-DP and VAR-EXT-HDMI respectively.<br> | ||
Selecting display configuration is a matter of selecting an appropriate | Selecting display configuration is a matter of selecting an appropriate dtb file.<br> | ||
On VAR-SOM-MX8 /boot/fsl-imx8qm-var-som.dtb is a symbolic link to the active | On VAR-SOM-MX8 /boot/fsl-imx8qm-var-som.dtb is a symbolic link to the active dtb file. By default it points to LVDS dtb.<br> | ||
To select HDMI display, run the following commands: | To select HDMI display, run the following commands: | ||
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# ln -fs fsl-imx8qm-var-som-dp.dtb fsl-imx8qm-var-som.dtb | # ln -fs fsl-imx8qm-var-som-dp.dtb fsl-imx8qm-var-som.dtb | ||
On SPEAR-MX8 /boot/fsl-imx8qm-var-spear.dtb is a symbolic link to the active | 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> | ||
To select HDMI display, run the following commands: | To select HDMI display, run the following commands: | ||
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The change will be effective after reboot.<br> | The change will be effective after reboot.<br> | ||
{{Note|Both firmware blob and | {{Note|Both firmware blob and dtb file should be set before rebooting the system, otherwise the boot process will get stuck.}} | ||
= Setting HDMI and DP resolution = | = Setting HDMI and DP resolution = | ||
Revision as of 10:18, 20 November 2019
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, to set 1080P resolution
[shell] size=3840x2160
For new settings to take effect restart weston by running
# systemctl restart weston