i.MX6D/Q: HDMI hot-plug detection in application

[Tarek]

Hi,

In my application I need to detect the HDMI display connected/disconnected and display resolution change. For example if the user replaced a 1080 display with a 720  I have to detect such change and rescale the output accordingly.

These are the kernel messages when swapping the displays:

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: WARNING: adapt panel end blank lines

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

mxc_sdc_fb mxc_sdc_fb.0: timeout when waiting for flip irq

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

imx-ipuv3 imx-ipuv3.0: IPU Warning - IPU_INT_STAT_5 = 0x08000000

How do I monitor the plug/unplug events of HDMI display?

Is there a direct API to read the monitor resolution from the application " Other than cat /sys/class/graphics/fb0/mode" ?

Thanks

[alejandrolozan1]

Hi,

Maybe you can try to read the EDID of the display.

You have to parse and translate the information to get the resolution.

To get the EDID you can dump the I2C at address 0x50.

I hope that helps,

Alejandro

[Tarek · Accepted solution]

Hi Alejandro,

I've used: $cat  /sys/devices/platform/mxc_hdmi/cable_state

Output = plugout or plugin

Thanks,

Tarek