userspace hdmi detection

[allanmatthew]

How would it be possible for a userspace application to detect the status of the HDMI connection on the i.mx6?  For instance, when the HDMI is connected to a monitor, I'd like to start a process.

[art]

Please refer to the Chapter 16 of the i.MX6 Series Linux BSP Reference Manual document, available as the part of the L3.14.28_1.0.0_LINUX_DOCS bundle on the Freescale web site (check the "Supporting Information" section):

http://www.freescale.com/products/arm-processors/i.mx-applications-processors-based-on-arm-cores/i.m...

In particular, it describes the hotplug detection capability of the L3.14.28 BSP HDMI driver.

Have a great day,
Artur

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[allanmatthew]

Hi Artur-

Thanks for this.  I looked through the documentation, but theres nothing obvious to me about the HPD status getting exposed to userspace.  It looks like it only generates an interrupt that the HDMI driver handles.

Is there a way to view the HPD status in userspace, like in sysfs or /proc?  Or do I need to look at a memory mapped register?

-Allan

[Sasamy · Accepted solution]

Hi Allan,

cable connection status can be seen in sysfs

linux-2.6-imx.git - Freescale i.MX Linux Tree

# find /sys -name cable_state

/sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state

# cat /sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state

plugin

# cat /sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state

plugout

Alexander