> -----Original Message----- > From: Baolin Wang [mailto:[email protected]] > Sent: Tuesday, March 29, 2016 5:49 PM > To: Jun Li <[email protected]> > Cc: Peter Chen <[email protected]>; Felipe Balbi <[email protected]>; > Greg KH <[email protected]>; Sebastian Reichel <[email protected]>; > Dmitry Eremin-Solenikov <[email protected]>; David Woodhouse > <[email protected]>; Peter Chen <[email protected]>; Alan Stern > <[email protected]>; [email protected]; Yoshihiro Shimoda > <[email protected]>; Lee Jones <[email protected]>; Mark > Brown <[email protected]>; Charles Keepax > <[email protected]>; [email protected]; > Linux PM list <[email protected]>; USB <[email protected]>; > [email protected]; LKML <linux- > [email protected]> > Subject: Re: [PATCH v8 0/4] Introduce usb charger framework to deal with > the usb gadget power negotation > > On 29 March 2016 at 16:45, Jun Li <[email protected]> wrote: > > > > > >> -----Original Message----- > >> From: [email protected] [mailto:linux-usb- > >> [email protected]] On Behalf Of Baolin Wang > >> Sent: Monday, March 28, 2016 2:52 PM > >> To: Peter Chen <[email protected]> > >> Cc: Felipe Balbi <[email protected]>; Greg KH > >> <[email protected]>; Sebastian Reichel <[email protected]>; > >> Dmitry Eremin-Solenikov <[email protected]>; David Woodhouse > >> <[email protected]>; Peter Chen <[email protected]>; Alan > >> Stern <[email protected]>; [email protected]; Yoshihiro > >> Shimoda <[email protected]>; Lee Jones > >> <[email protected]>; Mark Brown <[email protected]>; Charles > >> Keepax <[email protected]>; > >> [email protected]; > >> Linux PM list <[email protected]>; USB > >> <[email protected]>; > >> [email protected]; LKML <linux- > >> [email protected]> > >> Subject: Re: [PATCH v8 0/4] Introduce usb charger framework to deal > >> with the usb gadget power negotation > >> > >> On 25 March 2016 at 15:09, Peter Chen <[email protected]> wrote: > >> > On Thu, Mar 24, 2016 at 08:35:53PM +0800, Baolin Wang wrote: > >> >> Currently the Linux kernel does not provide any standard > >> >> integration of this feature that integrates the USB subsystem with > >> >> the system power regulation provided by PMICs meaning that either > >> >> vendors must add this in their kernels or USB gadget devices based > >> >> on Linux (such as mobile phones) may not behave as they should. > >> >> Thus provide a > >> standard framework for doing this in kernel. > >> >> > >> >> Now introduce one user with wm831x_power to support and test the > >> >> usb charger, which is pending testing. Moreover there may be other > >> >> potential users will use it in future. > >> >> > >> > > >> > I am afraid I still not find the user (udc driver) for this > >> > framework, I would like to see how udc driver block the enumeration > >> > until the charger detection has finished, or am I missing something? > >> > >> It is not for udc driver but for power users who want to negotiate > >> with USB subsystem. > >> > > > > Seems you don't want to guarantee charger type detection is done > > before gadget connection(pullup DP), right? > > I see you call usb_charger_detect_type() in each gadget usb state > changes. > > I am not sure I get your point correctly, please correct me if I > misunderstand you. > We need to check the charger type at every event comes from the usb gadget > state changes or the extcon device state changes, which means a new > charger plugin or pullup. >
According to usb charger spec, my understanding is you can't do real charger detection procedure *after* gadget _connection_(pullup DP), also I don't think it's necessary to check charger type at every event from usb gadget. Something in gadget driver you can utilize is only vbus detection, and report diff current by diff usb state if it's a SDP. > > > > Li Jun > >> > > >> > -- > >> > Best Regards, > >> > Peter Chen > >> > >> > >> > >> -- > >> Baolin.wang > >> Best Regards > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-usb" > >> in the body of a message to [email protected] More majordomo > >> info at http://vger.kernel.org/majordomo-info.html > > > > -- > Baolin.wang > Best Regards
