Hi Heikki, Sure, I will check about this. Thanks for advising me. Thanks in advance. Puma Hsu On Thu, Oct 24, 2019 at 8:06 PM Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> wrote: > > Hi, > > On Thu, Oct 24, 2019 at 05:02:18PM +0800, Puma Hsu wrote: > > Yes, generally this might be purely informational or be a dynamically > > debuggable > > mechanism for end user as I mentioned in previous discussion > > thread(https://lkml.org/lkml/2019/10/22/198). > > Could I know if it is not suitable that we expose a file for > > informational usage? > > > > If everyone agreed above, about the definition of “unknown” and the condition > > “don’t know the orientation”, what about adding additional return value? > > 1. For original “unknown”, it is a generic unknown state which can > > indicate no > > matter connector is disconnected, cannot specify which cc side > > is configured(such as Ra-Ra), > > or even driver can not know the orientation. > > 2. New additional value “unavailable”, it can be used to > > specifically explicate that > > driver can not know the orientation. > > Take UCSI as example, it can use generic “unknown” or “unavailable” if > > it wants. > > But if it exposes “unavailable”, then application in user space can > > know that this attribute is not useful. > > > > I summarize the proposal definition below: > > - unknown (generic unknown. driver don’t or can’t know the polarity, > > e.g. disconnected, both cc1 and cc2 are the same, ) > > - normal (configured in cc1 side) > > - reversed (configured in cc2 side) > > - unavailable (not support the polarity detection) > > Now the attribute would be supplying two types of information: > > 1) Does the driver know the orientation > 2) The current orientation > > Let's not do that! If you really need this, then just implement the > ".is_visible" callback with it. You just need to add a flag to the > struct typec_capability that tells does the driver know the > orientation or not. Something like: > > unsigned int orientation_aware:1; > > We already "hide" the identity information if the underlying driver > is unable to supply it. By making this attribute optional as well (by > hiding it when it's not known), the style of exposing the information > is kept the same throughout the class. > > thanks, > > -- > heikki
