I have a small embedded HDMI display, and I would like to add some monitor controls into the user interface. The display supports DDC/CI but my i.MX8 device tree does not expose the i2c lines for the HDMI port. I've searched through the linux-imx/arch/arm64/boot/dts/freescale files, and I can't find any examples of this.
Can somebody please help me to get access to the dedicated SDA/SCL for the HDMI interface?
Hi we've had a similar problem with wanting to send commands over the DDC lines.
Take a look at the cdns_hdmi_scdc_write function.
It is possible create a custom function similar to the cdns_hdmi_scdc. The data can be hardcoded in the driver and called from initialization or via sysfs interface.
Just make sure to have the 0 and 1 in the message in the same way as in the cdns_hdmi_scdc_write function otherwise the packet isn't sent properly. I believe it's some kind of message protocol to the mailbox register of the HDMI IP but I'm not entirely sure.
Best regards,
Darko
what imx8 processor do you use? imx8qm?
I'm using the i.MX 8M, I believe. It's a BCM AR8MXMQ board.