how to enable HDMI port on linux platform for imx8qm mek

[nakshatra_a]

I am working on xen for imx8qm mek board and used the boot environment setup " U-Boot > setenv displayinfo  'video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24' for an HDMI display " ,for linux (domain 0) as its default display. But I am not able to see any output on display from HDMI port. Can I get any solution for this.

linux: L4.19.35_1.1.0_LINUX.

thanking you

[igorpadykov]

Hi Nakshatra 

for i.MX8QM HDMI linux support one can look at Linux 4.19.35_1.1.0 Documentation:

in particular from Release Notes Table 10. Kernel and device tree configurations:

"fsl-imx8qm-mek.dtb: Support the LVDS-HDMI or MIPI-DSI-HDMI
display with the LVDS-HDMI or MIPI-DSI-HDMI converts."

i.MX 8 Series Accessory Boards | NXP 

Best regards
igor
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[felix_ye]

Dear igorpadykov,

I am working on i.MX8QM-MEK board, and I want to test the HDMI RX.

Is there any demo for HDMI RX test ?

For example, to test the camera input through MIPI CSI, I could run mx8_v4l2_cap_drm.out on Linux.

But I couldn't find a proper demo for HDMI RX in the imx-test repo.

I would appreciate it very much if you could give me some advices.

Thanks !

Felix

[igorpadykov]

Hi Felix

I am afraid so far there is no support for HDMI RX testing.

Best regards
igor

[felix_ye]

Dear igorpadykov,

All right. Thanks for your reply ~

I would try to write one by my own.

Another question please. Which device does the mxc_v4l2_tvin.out apply to?

Does it apply to camera input ?

And which platform on which could mxc_v4l2_tvin.out run ?

Best regards

Felix

[igorpadykov]

Hi Felix

it is used for processors with IPU, like i.MX6DQ/SDL.

Best regards
igor

[felix_ye]

Dear igorpadykov,

Thanks for your useful help !

And now I have problems running mxc_hdmi_probe() of mxc-hdmi-rx.c.

I found it would return error in hdmi_infoframe_poll() (mxc-hdmi-hw.c: 70).

In line 94 of mxc-hdmi-hw.c, it would read MHL_HD_INT_STAT from register.

        for (i = 0; i < 5; i++) {

            if (regresp.val & (1 << 0))
                break;
            else
                CDN_API_General_Read_Register_blocking(state,
                               ADDR_SINK_MHL_HD + (MHL_HD_INT_STAT << 2), &regresp);
            msleep(20);
        }
        if (i == 5) {
            dev_err(&hdmi_rx->pdev->dev, "Waiting for tmds_mhl_hd_int...failed!\n");
            return -1;
        } else
            dev_dbg(&hdmi_rx->pdev->dev, "Waiting for tmds_mhl_hd_int...DONE\n");

If it could not read the correct value in (20x5) ms, it would return error.

So, why was it happen ? I do have my HDMI RX plugged in.

And the HDMI RX data source is my laptop. If my laptop connects to a HDMI display device, it works.

Could you give me some advices ?

Thank you very much !

Best regards

Felix

[nakshatra_a]

Hello,

    I am able to get the LVDS-HDMI display. but for domain0 that is linux need HDMI display and for DomainU that is Android needs LVDS display. And i am planning to have both the displays sharing same display board. So can you help me how to get HDMI display independently.

Thanking you

Nakshatra