DESK-MX6-L/Pheripherals/HDMI

History
Version	Issue Date	Notes
1.0.0	Oct 2020	First DESK release

Contents

Peripheral HDMIEdit

Device tree configurationEdit

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 peripheralEdit

For enabling the HDMI device, it is required to instantiate its framebuffer with the related configuration, 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";
}

Linux messages at boot timeEdit

...
...
[    2.358974] 20e0000.hdmi_video supply HDMI not found, using dummy regulator
...
...
[    2.818470] mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x13:0x1a:0xa0:0xc1
...
...
[    2.831348] mxc_sdc_fb fb@2: registered mxc display driver hdmi...

Additional informationEdit

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

root@desk-mx6:~#

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