topic Re: IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem in i.MX Processors

IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem

pavelko — Wed, 15 Jan 2025 14:10:49 GMT

Hello,

back to 4.19 warrior I have used this configuration of sn65dsi84 DSI to LVDS bridge in device tree:

&i2c1 {
  clock-frequency = <400000>;
  pinctrl-names = "default";
  pinctrl-0 = <&pinctrl_i2c1>;
  status = "okay";

  dsi_lvds_bridge: sn65dsi84@2c {
    compatible = "ti,sn65dsi83";
    reg = <0x2c>;
    ti,dsi-lanes = <4>;
    ti,lvds-format = <2>;
    ti,lvds-channels = <1>;
    ti,lvds-bpp = <24>;
    ti,width-mm = <210>;
    ti,height-mm = <157>;
    ti,burst-mode;
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_lvds>;
    enable-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>;
    status = "okay";

    display-timings {
      lvds {
        clock-frequency = <65000000>;
        hactive = <1024>;
        vactive = <768>;
        /* */
        hfront-porch = <24>;
        hsync-len = <136>;
        hback-porch = <160>;
        /* */
        vfront-porch = <3>;
        vsync-len = <6>;
        vback-porch = <29>;
        /* */
        vsync-active = <0>;
        hsync-active = <0>;
        de-active = <1>;
        pixelclk-active = <1>;
     };
  };

  port {
    lvds_from_dsi: endpoint {
      remote-endpoint = <&dsi_to_lvds>;
    };
  };
};
};

&mipi_dsi {
  status = "okay";

  port@1 {
    dsi_to_lvds: endpoint {
      remote-endpoint = <&lvds_from_dsi>;
    };
  };
};

&iomuxc {
  pinctrl_i2c1: i2c1grp {
    fsl,pins = <
      MX8MM_IOMUXC_I2C1_SCL_I2C1_SCL 0x400001c3
      MX8MM_IOMUXC_I2C1_SDA_I2C1_SDA 0x400001c3
    >;
  };

  pinctrl_lvds: lvdsgrp {
    fsl,pins = <
      MX8MM_IOMUXC_GPIO1_IO12_GPIO1_IO12 0x16
    >;
  };
};

However, when I ported the device tree to yocto scarthgap (Linux 6.6) this definition is not working anymore:

[ 1.290572] imx-drm display-subsystem: bound imx-lcdif-crtc.0 (ops lcdif_crtc_ops)
[ 1.298317] imx_sec_dsim_drv 32e10000.mipi_dsi: version number is 0x1060200
[ 1.305343] [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@32c00000/mipi_dsi@32e10000 to encoder DSI-34: -19
[ 1.316955] imx_sec_dsim_drv 32e10000.mipi_dsi: Failed to attach bridge: 32e10000.mipi_dsi
[ 1.325231] imx_sec_dsim_drv 32e10000.mipi_dsi: failed to bind sec dsim bridge: -19
[ 1.332903] imx-drm display-subsystem: bound 32e10000.mipi_dsi (ops imx_sec_dsim_ops)
[ 1.341048] [drm] Initialized imx-drm 1.0.0 20120507 for display-subsystem on minor 0
[ 1.348908] imx-drm display-subsystem: [drm] Cannot find any crtc or sizes

Could anyone point me an example device tree setup for sn65dsi8(3/4/5) + imx8mm + Linux 6.6

Thanks in advance.

Re: IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem

Manuel_Salas — Thu, 16 Jan 2025 13:17:46 GMT

Hello @pavelko

I hope you are doing very well.

You can take a look into the sn65dsi83 binding in the linux kernel.

Also, you can try with this modified device tree:

&i2c1 { clock-frequency = <400000>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_i2c1>; status = "okay"; dsi_lvds_bridge: sn65dsi84@2c { compatible = "ti,sn65dsi83"; reg = <0x2c>; enable-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>; status = "okay"; ports { #address-cells = <1>; #size-cells = <0>; port@0 { reg = <0>; bridge_in: endpoint { remote-endpoint = <&mipi_dsi_out>; data-lanes = <1 2 3 4>; }; }; port@2 { reg = <2>; bridge_out: endpoint { remote-endpoint = <&panel_in>; }; }; }; }; }; &mipi_dsi { status = "okay"; port@1 { reg = <1>; mipi_dsi_out: endpoint { remote-endpoint = <&bridge_in>; data-lanes = <1 2 3 4>; }; }; }; panel_lvds: panel { compatible = "panel-lvds"; data-mapping = "jeida-24"; width-mm = <210>; height-mm = <157>; panel-timing { clock-frequency = <65000000>; hactive = <1024>; vactive = <768>; hfront-porch = <24>; hsync-len = <136>; hback-porch = <160>; vfront-porch = <3>; vsync-len = <6>; vback-porch = <29>; hsync-active = <0>; vsync-active = <0>; de-active = <1>; pixelclk-active = <1>; }; port { panel_in: endpoint { remote-endpoint = <&bridge_out>; }; }; };

It should align with the 6.6 kernel version.

Best regards,

Salas.

Re: IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem

pavelko — Thu, 16 Jan 2025 13:08:45 GMT

Thank you for the answer.

To accept it as an answer "port 1" in sn65dsi declaration shall be renamed to "port 2", as port 1 is used foe 2nd DSI output channel. and correct reg =<1> to reg=<2> accordingly.

Thank you!

Re: IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem

Manuel_Salas — Thu, 16 Jan 2025 13:18:30 GMT

Hello @pavelko

I updated the post, please check it, also, thank you for the feedback!

Best regards,

Salas.

Re: IMX8MM + sn65dsi83 + yocto scarthgap = devicetree problem

pavelko — Thu, 16 Jan 2025 13:21:43 GMT

Thank you for your solution!

Best Regards,

Pavel