The Texas Instruments SN65DSI83 MIPI-to-LVDS bridge converts the {cpu-family} MIPI-DSI signal to one suitable for LVDS displays.
To use this bridge, set the S1.4 micro-switch to ON.
Kernel configuration
You can manage the SN65DSI83 support through the following kernel configuration option:
-
TI SN65DSI83 MIPI DSI to LVDS bridge (
CONFIG_DRM_I2C_SN65DSI83)
This option is enabled as built-in on the default ConnectCore 8M Mini kernel configuration file.
Kernel driver
The driver for the SN65DSI83 bridge is located at:
| File | Description |
|---|---|
SN65DSI83 MIPI-to-LVDS core driver |
|
SN65DSI83 MIPI-to-LVDS bridge driver |
Device tree bindings and customization
The SN65DSI83 bridge is defined in the ConnectCore 8M Mini Development Kit device tree file. Two LCD displays are defined within it:
-
AUO 10.1" (G101EVN01.0)
-
Fusion 10.1" (F10A-0102)
Definition of the LVDS bridge and LCD displays
&i2c3 {
clock-frequency = <100000>;
pinctrl-names = "default", "gpio";
pinctrl-0 = <&pinctrl_i2c3>;
pinctrl-1 = <&pinctrl_i2c3_gpio>;
scl-gpios = <&gpio5 18 GPIO_ACTIVE_HIGH>;
sda-gpios = <&gpio5 19 GPIO_ACTIVE_HIGH>;
status = "okay";
dsi_lvds_bridge: sn65dsi84@2c {
compatible = "ti,sn65dsi83";
reg = <0x2c>;
ti,dsi-lanes = <4>;
ti,lvds-format = <1>;
ti,lvds-bpp = <24>;
ti,width-mm = <217>;
ti,height-mm = <136>;
enable-gpios = <&gpio3 0 GPIO_ACTIVE_HIGH>;
interrupt-parent = <&gpio3>;
interrupts = <6 IRQ_TYPE_LEVEL_HIGH>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lvds>;
status = "disabled";
display-timings {
native-mode = <&lvds0_g101evn010>;
/* AUO G101EVN01.0 */
lvds0_g101evn010: timing@0 {
clock-frequency = <69000000>;
hactive = <1280>;
vactive = <800>;
hfront-porch = <120>;
hback-porch = <1>;
hsync-len = <8>;
vback-porch = <10>;
vfront-porch = <1>;
vsync-len = <6>;
hsync-active = <1>;
vsync-active = <1>;
de-active = <1>;
pixelclk-active = <0>;
};
/* Fusion 10" F10A-0102 */
lvds0_hsd101pfw2: timing@1 {
clock-frequency = <45000000>;
hactive = <1024>;
vactive = <600>;
hfront-porch = <120>;
hback-porch = <1>;
hsync-len = <8>;
vback-porch = <10>;
vfront-porch = <1>;
vsync-len = <6>;
hsync-active = <1>;
vsync-active = <1>;
de-active = <1>;
pixelclk-active = <0>;
};
};
port {
dsi_lvds_bridge_in: endpoint {
remote-endpoint = <&mipi_dsi_lvds_out>;
};
};
};
...
};
...
&mipi_dsi {
status = "okay";
...
port@2 {
mipi_dsi_lvds_out: endpoint {
remote-endpoint = <&dsi_lvds_bridge_in>;
};
};
};IOMUX configuration
The following IOMUX entry configures the associated enable and interrupt GPIO pins.
pinctrl_lvds: lvdsgrp {
fsl,pins = <
/* SN65DSI83 enable */
MX8MM_IOMUXC_NAND_ALE_GPIO3_IO0 0x19
/* SN65DSI83 interrupt */
MX8MM_IOMUXC_NAND_DATA00_GPIO3_IO6 0x19
>;
};Configure LVDS as default bridge
The Linux DRM subsystem only allows one MIPI bridge to be used at a time. By default, the LVDS bridge is disabled and the HDMI one is enabled. To use the LVDS interface instead of the HDMI one on the ConnectCore 8M Mini Development Kit:
-
Disable the LT8912 MIPI-to-HDMI bridge in the device tree
-
Enable the SN65DSI83 MIPI-to-LVDS bridge in the device tree
Digi provides pre-compiled device tree overlays that do exactly this, so that you can test the LVDS interface without needing to recompile a device tree. To apply one of these overlays, run the following command in U-Boot:
-
To enable the LVDS with the AUO 10" LCD display:
=> setenv overlays _ov_board_lvds_ccimx8m-dvk.dtbo
See Device tree files and overlays for more information.
