On 2017-03-03 13:59, Heikki Krogerus wrote:
On Fri, Mar 03, 2017 at 08:29:18AM +0100, Mats Karrman wrote:
....
How would something like that sound to you guys?
Complicated... Need to marinate on that for a while ;)
My system is a bit different. It's an i.MX6 SoC with the typec phy and DP controller connected
directly to the SoC and it's using DTB/OF.
Is this "DP controller" a controller that is capable of taking care of
the USB Power Delivery communication with the partner regarding
DisplayPort alternate mode?
No, the "DP controller" just talks DP and knows nothing about Type-C or USB PD.
It takes a video stream from the SoC and turns it into a DP link, set up and orchestrated
by the corresponding driver. And all the driver needs from Type-C is the plugged in / interrupt /
plugged out events.
The analog switching between USB / safe / DP signal levels in the Type-C connector is, I think,
best handled by the software doing the USB PD negotiation / Altmode handling (using some GPIOs).
Do we need to further standardize attributes under (each) specific alternate mode to
include things such as HPD for the DP mode?
I'm not completely sure what kind of system you have, but I would
imagine that if we had the bus, your DP controller driver would be the
port (and partner) alternate mode driver. The bus would bind you to
the typec phy.
So, both the DP controller and the USB PD phy are I2C devices, and now I have to make them both
attach to the AM bus as well?
BR,
Mats
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