From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Jun Subject: Re: [PATCH v6] usb: common: add API to set usb otg capabilities by device tree Date: Tue, 23 Jun 2015 16:35:49 +0800 Message-ID: <20150623083548.GD25349@shlinux2> References: <1434590302-18066-1-git-send-email-jun.li@freescale.com> <20150618103650.7c3d1b8ceb134388b0d8b093@ti.com> <20150618084747.GD15280@shlinux2> <20150618150748.db2217278ae71f01df625ff2@ti.com> <20150618133703.GF15280@shlinux2> <20150622124122.a3155a04430083b24d775aa4@ti.com> <20150622104535.GA25349@shlinux2> <20150622163256.418a1b05d9848a7342669fe4@ti.com> <20150622143638.GC25349@shlinux2> <20150623104328.5aac8e83bc23050c7541aee8@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20150623104328.5aac8e83bc23050c7541aee8-l0cyMroinI0@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roger Quadros Cc: Li Jun , gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, balbi-l0cyMroinI0@public.gmane.org, peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, macpaul-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: devicetree@vger.kernel.org On Tue, Jun 23, 2015 at 10:43:28AM +0300, Roger Quadros wrote: > > > > > > If the dr_mode was "otg" for such case and we want OTG disabled then it is really the DT fault. > > > > It's ID pin detect for dual role switch as many current OTG controllers have. > > not DT fault, its dt only has a dr_mode = "otg". > > > > > We don't need to tackle this case. Just fix up the DT to dr_mode = "peripheral" if > > > OTG behaviour is not needed. > > > > > OTG behaviour is not needed, so we need disable HNP/SRP/ADP. but dr_mode = > > "otg" as it already works fine with ID pin detect. > > Do you know which platform has plain non-otg dual-role working as of today > with dr_mode set to "otg"? I don't know. The dt property dr_mode is already there, and currently there are some platforms as its user, so I assume those platforms either are non-otg dual-role, or real OTG with HNP supported, I guess most are the former cases; chipidea is the later case. > For TI platforms none of them have it working currently. > So for Ti platforms, some enables non-otg dual-role function but do not use dr_mode = "otg"? For those only have non-otg dual-role platforms, no matter using dr_mode or not, we need keep it's real OTG disabled for legacy users after it's controller driver adds real OTG later. > > > > > > > > > > How I make one decision in of_usb_updade_otg_caps() > > > > for above 2 cases?(the otg-rev is 0 for both). > > > > > > > > > > For case 3. otg-rev passed by controller is not 0. otg-rev is just not present in DT. > > > > > > > Current OTG situation is not so simple, so that we can not use one simple > > rule to handle legacy cases in a common place, but for a particular controller > > driver, make decision on this is a simple work, I think. > > OK. Let's continue with your apporach. Maybe USB maintainers can give their opinion > as well. > If some simple handling for all legacy platforms can be accepted, I am happy to follow it in of_usb_update_otg_caps(). Felipe, Peter, any comments on this? Li Jun > Later if more controllers are trying to do the same thing then we can introduce a helper > function for those controllers. > Agree. > cheers, > -roger -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html