DESK-MX6-L/Peripherals/HDMI

History
Issue Date	Notes
2021/07/16	First DESK-MX6-L release
2022/08/26	DESK-MX6-L 3.0.0 release
2023/04/11	DESK-MX6-L 4.0.0 release

Peripheral HDMI

Device tree configuration

Here below an example of device tree configuration used on standard DAVE's kit for the AXELLite SOM:

From imx6qdl-sbcx-revb-common.dtsi:

    hdmi_edid: edid@50 {
        compatible = "fsl,imx6-hdmi-i2c";
        reg = <0x50>;
    };

From imx6qdl-axelcommon.dtsi:

&hdmi_cec {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_hdmi_cec_2>;
    status = "okay";
};

&hdmi_core {
    ipu_id = <0>;
    disp_id = <0>;
    status = "okay";
};

&hdmi_video {
    fsl,phy_reg_vlev = <0x0294>;
    fsl,phy_reg_cksymtx = <0x800d>;
    status = "okay";
};

&iomuxc {
...
...
    hdmi_cec {
        pinctrl_hdmi_cec_2: hdmicecgrp-2 {
            fsl,pins = <
                MX6QDL_PAD_KEY_ROW2__HDMI_TX_CEC_LINE 0x1f8b0
            >;
        };
    };
...
...
};

Accessing the peripheral

For enabling the HDMI device, it is required to instantiate its framebuffer with the related configuration and changing the display ID of hdmi_core, for example, with a 1920x1080p60 display:

&mxcfb3 {
	compatible = "fsl,mxc_sdc_fb";
	disp_dev = "hdmi";
	interface_pix_fmt = "RGB24";
	mode_str ="1920x1080M@60";
	default_bpp = <32>;
	status = "okay";
};

&hdmi_core {
    ipu_id = <0>;
    disp_id = <1>;
    status = "okay";
};

Linux messages at boot time

...
...
[    3.784909] mxc_hdmi 20e0000.hdmi_video: supply HDMI not found, using dummy regulator
[    4.098068] mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x13:0x1a:0xa0:0xc1
[    4.110974] mxc_sdc_fb fb@2: registered mxc display driver hdmi
...
...

Additional information

HDMI framebuffer can be accessed through the standard /dev/fbX fb device.

The configured framebuffer can be checked using standard fbset utility:

root@desk-mx6:~# fbset -fb /dev/fb2 

mode "1920x1080-60"
    # D: 148.500 MHz, H: 67.500 kHz, V: 60.000 Hz
    geometry 1920 1080 1920 1080 32
    timings 6734 148 88 36 4 44 5
    hsync high
    vsync high
    rgba 8/16,8/8,8/0,8/24
endmode

---