From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v6] usb: common: add API to set usb otg capabilities by device tree Date: Wed, 08 Jul 2015 14:05:39 -0600 Message-ID: <559D8293.7020904@wwwdotorg.org> 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> <20150623083548.GD25349@shlinux2> <20150623145606.f3f617586c9253036c4d6022@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150623145606.f3f617586c9253036c4d6022-l0cyMroinI0@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roger Quadros Cc: Li Jun , kgene-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, 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 06/23/2015 05:56 AM, Roger Quadros wrote: > + Kukjin, Stephen, > > for board specific USB question. > > On Tue, 23 Jun 2015 16:35:49 +0800 > Li Jun wrote: > >> 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 TI we have only musb based and dwc3 based platforms. MUSB based are OTG. > dwc3 doesn't support dual-role or OTG yet so we use either "peripheral" or "Host" > >> >> 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. > > I wouldn't even bother about platforms expecting dual-role behaviour > with dr_mode not set to "otg". That is just plain wrong and can't be supported. > > These are the dts files having dr_mode == "otg". > I've sorted them as per Soc vendor and USB controller ... > Nvidia > ------ > arm/boot/dts/tegra20-seaboard.dts: dr_mode = "otg"; > compatible = "nvidia,tegra20-ehci", "usb-ehci"; > arm/boot/dts/tegra30-colibri-eval-v3.dts: dr_mode = "otg"; > compatible = "nvidia,tegra30-ehci", "usb-ehci"; > > I couldn't find gadget side implementation for this. > Stephen, any comments on whether this board supports true OTG operation or just dual-role operation? Sorry for the slow reply; I was on vacation. I'm not sure what the difference is? I won't be able to answer for the Colibri board since I'm not familiar with the HW. I have the schematics for Seaboard, so I should be able to answer once I understand the question:-) -- 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