On Mon, Feb 25, 2019 at 08:14:55PM +0100, Hans de Goede wrote: > Hi, > > On 25-02-19 16:48, Heikki Krogerus wrote: > > On Fri, Feb 22, 2019 at 05:31:32PM +0100, Hans de Goede wrote: > > > Hi, > > > > > > On 2/19/19 12:59 PM, Heikki Krogerus wrote: > > > > Hi guys, > > > > > > > > The software nodes support node hierarchy. By using them with fusb302 > > > > we can add a separate fwnode also for the USB connector as a child of > > > > fusb302. We can then use the "standard" USB connector device > > > > properties with the connector node, and stop using the deprecated > > > > fusb302 specific properties. > > > > > > > > Since the goal is to ultimately move to the software node API from the > > > > old device property API, converting also max17047 in this series. > > > > > > > > If you test this now (before v5.1-rc1 is out), then the series depends > > > > Greg's latest usb-next: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/log/?h=usb-next > > > > > > > > and on a patch in Rafael's latest linux-next branch: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=linux-next&id=344798206f171c5abea7ab1f9762fa526d7f539d > > > > > > Interesting series, I like the direction this is heading in. > > > > > > Question, I currently have this hack to test DP over Type-C on the > > > GPD-pocket / GPD-win: > > > > > > https://github.com/jwrdegoede/linux-sunxi/commit/f481b7032030dcdda1ccc39875eb59f996d3e775 > > > > > > Do this properly we need to add alt-modes support for usb-c-connector nodes to: > > > Documentation/devicetree/bindings/connector/usb-connector.txt > > > > Yes, this is a topic I wanted to talk about. > > > > > Do you have any ideas for what the binding this should look like, we need to > > > specify a svid, mode and vdo tripple in this case. Maybe use an u32 array > > > with 3, 6, 9, ... entries depending on how much alt-modes the fwnode needs to > > > specify ? > > > > My idea was to use sub-nodes, i.e. every alt mode a connector supports > > would need to have its own child node under the connector node. Those > > sub-nodes could then have a device property "svid" and another device > > property "vdo", etc. > > Right, after sending this mail I realized myself that using child-nodes > to group the svid and vdo together was the right answer. So we > could add child-nodes with a binding like this: > > Optionally an "usb-c-connector" can have child nodes, describing > supported alt-modes. > > Required properties for usb-c-connector altmode child-nodes: > compatible: "usb-type-c-altmode" > svid: integer, Standard or Vendor ID for the altmode (u16 stored in an u32) property and an u32 > vdo: integer, Vendor Data Object, VDO describing the altmode capabilies, SVID specific > > I'm not sure if we also need to specify the altmode index here, or > we simple assign each alt-mode an index while enumerating? I don't think we need the index. SVID and VDO are enough. > > I think that approach would be OK in DT, and we can now support it also > > with the software nodes, and even in ACPI there are now something > > called "data nodes" which can be used for this purpose. > > Ack. > > > There are some questions though. That "USB connector" node description > > relies on OF graph, so should we just extend those "endpoint" nodes > > (which are sub-nodes), or should be still have dedicated sub-nodes for > > the alt modes? I think we may need dedicated nodes for the alt modes > > in any case if we choose to use this approach. > > Right I'm thinking dedicated nodes for the alt modes. > > I guess an alt-mode could have a port child-node to point to say the > DisplayPort pins / mux connection ? I'm not entirely sure how the graph > stuff will work here, but I guess that from a DT pov it will be desirable > to be able to describe where the datalines for the alt-mode come from, > maybe in combination with what the "mux/select" value is for the mux ??? I don't know what is the correct approach here. In a way it would feel logical to assign the mux connection to the alt mode child-node, but on the other hand the alt mode child-nodes are not real "device nodes" that represent some physical device like the connector node does. The alt mode child-node is more like a representation of a device function. It is unlikely that a connector has multiple muxes to deal with even when it supports multiple alt modes. I think if I had to vote on this, I would prefer to link the muxing with the connector node, and not the alt mode child-node. thanks, -- heikki
