MX8 Display: Difference between revisions
No edit summary |
No edit summary |
||
Line 7: | Line 7: | ||
= Selecting display type = | = Selecting display type = | ||
VAR-SOM-MX8 | 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 DTB file.<br> | 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 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: | ||
Line 20: | Line 20: | ||
# cd /boot | # cd /boot | ||
# 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 DTB file. By default it points to LVDS DTB.<br> | |||
To select HDMI display, run the following commands: | |||
# cd /boot | |||
# ln -fs fsl-imx8qm-var-spear-hdmi.dtb fsl-imx8qm-var-spear.dtb | |||
To select DP display, run the following commands: | |||
# cd /boot | |||
# ln -fs fsl-imx8qm-var-spear-dp.dtb fsl-imx8qm-var-spear.dtb | |||
The change will be effective after reboot.<br> | The change will be effective after reboot.<br> | ||
Line 70: | Line 81: | ||
To support different LVDS panel, several modifications may be required. | To support different LVDS panel, several modifications may be required. | ||
{{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX8X| | |||
The following code configures LVDS panel in arch/arm64/boot/dts/freescale/fsl-imx8qxp-var-som-common.dtsi under kernel source tree: | |||
<pre> | <pre> | ||
&ldb1_phy { | &ldb1_phy { | ||
Line 106: | Line 117: | ||
</pre> | </pre> | ||
| | | | ||
On VAR-SOM-MX8 LVDS panel is configured in arch/arm64/boot/dts/freescale/fsl-imx8qm-var-som-lvds.dtsi under kernel source tree: | |||
On SPEAR-MX8 LVDS panel is configured in arch/arm64/boot/dts/freescale/fsl-imx8qm-var-spear-lvds.dtsi | |||
<pre> | <pre> | ||
&ldb1_phy { | &ldb1_phy { |
Revision as of 16:34, 7 October 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