Hi Mats, On Fri, Mar 03, 2017 at 08:27:08PM +0100, Mats Karrman wrote: > 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 ;) Sorry about the bad explanation :-). Let me try again.. I'm simply looking for a method that is as scalable as possible to handle the alternate modes, basically how to couple the different components involved. Bus would feel like the best approach at the moment. > > > 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. Got it. > 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? The DP controller would provide the driver and the USB PD phy (actually, the typec class) the device. Would it be a problem to register these I2C devices with some other subsystem, was it extcon or something like AM bus? It really would not be that uncommon. Or have I misunderstood your question? Thanks, -- heikki -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
