From: Felipe Balbi <balbi@kernel.org> To: Peter Chen <hzpeterchen@gmail.com> Cc: Roger Quadros <rogerq@ti.com>, peter.chen@freescale.com, tony@atomide.com, gregkh@linuxfoundation.org, dan.j.williams@intel.com, mathias.nyman@linux.intel.com, Joao.Pinto@synopsys.com, sergei.shtylyov@cogentembedded.com, jun.li@freescale.com, grygorii.strashko@ti.com, yoshihiro.shimoda.uh@renesas.com, robh@kernel.org, nsekhar@ti.com, b-liu@ti.com, joe@perches.com, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v11 08/14] usb: otg: add OTG/dual-role core Date: Mon, 20 Jun 2016 15:08:15 +0300 [thread overview] Message-ID: <8737o8qd00.fsf@linux.intel.com> (raw) In-Reply-To: <20160620114904.GC26936@shlinux2> [-- Attachment #1: Type: text/plain, Size: 2488 bytes --] Hi, Peter Chen <hzpeterchen@gmail.com> writes: >> Roger Quadros <rogerq@ti.com> writes: >> > It provides APIs for the following tasks >> > >> > - Registering an OTG/dual-role capable controller >> > - Registering Host and Gadget controllers to OTG core >> > - Providing inputs to and kicking the OTG state machine >> >> I think I have already mentioned this, but after over 10 years of OTG, >> nobody seems to care about it, why are we still touching at all I don't >> know. For common non-OTG role-swapping we really don't need any of this >> and, quite frankly, I fail to see enough users for this. >> >> Apparently there's only chipidea which, AFAICT, already had working >> dual-role before this OTG State Machine was added to the kernel. > > Some users would like to know if vendor's platform is OTG compliance, > so we add it to pass usb.org USB OTG certification test. I strongly doubt that's really what they mean. IMHO, users want to know if they can swap roles. Ask them if they are really going for OTG certification. Ask them if they have an OPT tester. Ask them if they really want all those timers. If they want HNP polling, etc etc etc. So far, I haven't seen anybody talking about real USB OTG (the spec) when they say OTG. Usually they just mean "a method for swapping between host and peripheral roles, but we really don't want all the extra cost of the OTG specification". > For the real use case, some Carplay platforms need it. Carplay does *NOT* rely on OTG. Apple has its own proprietary and closed specification which is not OTG-compliant. >> > diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h >> > index f4fc0aa..1d74fb8 100644 >> > --- a/include/linux/usb/gadget.h >> > +++ b/include/linux/usb/gadget.h >> > @@ -328,6 +328,7 @@ struct usb_gadget_ops { >> > * @in_epnum: last used in ep number >> > * @mA: last set mA value >> > * @otg_caps: OTG capabilities of this gadget. >> > + * @otg_dev: OTG controller device, if needs to be used with OTG core. >> >> do you really know of any platform which has a separate OTG controller? >> > > It may not be a real separate OTG controller. It can be a hardware part > (external connector, external IC, SoC OTG register area, etc) to handle vbus > ,id and other signals which are used for role swap. That's already solved. EXTCON solved that years back and OMAP has been using EXTCON to program its UTMI mailbox. -- balbi [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 818 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Felipe Balbi <balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> To: Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Cc: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>, peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org, tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, mathias.nyman-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, Joao.Pinto-HKixBCOQz3hWk0Htik3J/w@public.gmane.org, sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org, jun.li-KZfg59tc24xl57MIdRCFDg@public.gmane.org, grygorii.strashko-l0cyMroinI0@public.gmane.org, yoshihiro.shimoda.uh-zM6kxYcvzFBBDgjK7y7TUQ@public.gmane.org, robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, nsekhar-l0cyMroinI0@public.gmane.org, b-liu-l0cyMroinI0@public.gmane.org, joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: Re: [PATCH v11 08/14] usb: otg: add OTG/dual-role core Date: Mon, 20 Jun 2016 15:08:15 +0300 [thread overview] Message-ID: <8737o8qd00.fsf@linux.intel.com> (raw) In-Reply-To: <20160620114904.GC26936@shlinux2> [-- Attachment #1: Type: text/plain, Size: 2540 bytes --] Hi, Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes: >> Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org> writes: >> > It provides APIs for the following tasks >> > >> > - Registering an OTG/dual-role capable controller >> > - Registering Host and Gadget controllers to OTG core >> > - Providing inputs to and kicking the OTG state machine >> >> I think I have already mentioned this, but after over 10 years of OTG, >> nobody seems to care about it, why are we still touching at all I don't >> know. For common non-OTG role-swapping we really don't need any of this >> and, quite frankly, I fail to see enough users for this. >> >> Apparently there's only chipidea which, AFAICT, already had working >> dual-role before this OTG State Machine was added to the kernel. > > Some users would like to know if vendor's platform is OTG compliance, > so we add it to pass usb.org USB OTG certification test. I strongly doubt that's really what they mean. IMHO, users want to know if they can swap roles. Ask them if they are really going for OTG certification. Ask them if they have an OPT tester. Ask them if they really want all those timers. If they want HNP polling, etc etc etc. So far, I haven't seen anybody talking about real USB OTG (the spec) when they say OTG. Usually they just mean "a method for swapping between host and peripheral roles, but we really don't want all the extra cost of the OTG specification". > For the real use case, some Carplay platforms need it. Carplay does *NOT* rely on OTG. Apple has its own proprietary and closed specification which is not OTG-compliant. >> > diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h >> > index f4fc0aa..1d74fb8 100644 >> > --- a/include/linux/usb/gadget.h >> > +++ b/include/linux/usb/gadget.h >> > @@ -328,6 +328,7 @@ struct usb_gadget_ops { >> > * @in_epnum: last used in ep number >> > * @mA: last set mA value >> > * @otg_caps: OTG capabilities of this gadget. >> > + * @otg_dev: OTG controller device, if needs to be used with OTG core. >> >> do you really know of any platform which has a separate OTG controller? >> > > It may not be a real separate OTG controller. It can be a hardware part > (external connector, external IC, SoC OTG register area, etc) to handle vbus > ,id and other signals which are used for role swap. That's already solved. EXTCON solved that years back and OMAP has been using EXTCON to program its UTMI mailbox. -- balbi [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 818 bytes --]
next prev parent reply other threads:[~2016-06-20 12:10 UTC|newest] Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-10 13:07 [PATCH v10 00/14] USB OTG/dual-role framework Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 01/14] usb: hcd: Initialize hcd->flags to 0 Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-14 8:16 ` Roger Quadros 2016-06-14 8:16 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 02/14] usb: otg-fsm: Prevent build warning "VDBG" redefined Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 03/14] usb: hcd.h: Add OTG to HCD interface Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-14 8:17 ` Roger Quadros 2016-06-14 8:17 ` Roger Quadros 2016-06-14 14:21 ` Alan Stern 2016-06-14 14:21 ` Alan Stern 2016-06-15 7:14 ` Roger Quadros 2016-06-15 7:14 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 04/14] usb: otg-fsm: use usb_otg wherever possible Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 05/14] usb: otg-fsm: move host controller operations into usb_otg->hcd_ops Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 06/14] usb: gadget.h: Add OTG to gadget interface Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-12 9:13 ` Peter Chen 2016-06-20 7:21 ` Felipe Balbi 2016-06-20 7:21 ` Felipe Balbi 2016-06-20 7:28 ` Roger Quadros 2016-06-20 7:28 ` Roger Quadros 2016-06-20 8:13 ` Felipe Balbi 2016-06-20 8:13 ` Felipe Balbi 2016-06-20 8:25 ` Roger Quadros 2016-06-20 8:25 ` Roger Quadros 2016-06-20 9:24 ` Felipe Balbi 2016-06-20 9:24 ` Felipe Balbi 2016-06-20 9:43 ` Roger Quadros 2016-06-20 9:43 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 07/14] usb: otg: get rid of CONFIG_USB_OTG_FSM in favour of CONFIG_USB_OTG Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 08/14] usb: otg: add OTG/dual-role core Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-12 11:21 ` Peter Chen 2016-06-12 11:21 ` Peter Chen 2016-06-13 7:42 ` Roger Quadros 2016-06-13 7:42 ` Roger Quadros 2016-06-13 7:56 ` [PATCH v11 " Roger Quadros 2016-06-13 7:56 ` Roger Quadros 2016-06-13 7:58 ` Peter Chen 2016-06-20 7:45 ` Felipe Balbi 2016-06-20 7:45 ` Felipe Balbi 2016-06-20 10:13 ` Roger Quadros 2016-06-20 10:13 ` Roger Quadros 2016-06-20 12:03 ` Felipe Balbi 2016-06-20 12:26 ` Roger Quadros 2016-06-20 12:26 ` Roger Quadros 2016-06-20 12:46 ` Felipe Balbi 2016-06-21 6:39 ` Peter Chen 2016-06-21 7:19 ` Felipe Balbi 2016-06-21 7:19 ` Felipe Balbi 2016-06-21 8:02 ` Peter Chen 2016-06-21 8:18 ` Felipe Balbi 2016-06-21 8:18 ` Felipe Balbi 2016-06-21 9:14 ` Peter Chen 2016-06-21 9:14 ` Peter Chen 2016-06-21 12:35 ` Felipe Balbi 2016-06-21 12:35 ` Felipe Balbi 2016-06-21 13:12 ` Peter Chen 2016-06-21 14:47 ` Felipe Balbi 2016-06-22 3:33 ` Peter Chen 2016-06-22 3:33 ` Peter Chen 2016-06-22 6:51 ` Felipe Balbi 2016-06-22 6:51 ` Felipe Balbi 2016-06-22 7:30 ` Peter Chen 2016-06-22 7:30 ` Peter Chen 2016-06-22 8:00 ` Felipe Balbi 2016-06-22 8:00 ` Felipe Balbi 2016-06-23 7:41 ` Yoshihiro Shimoda 2016-06-23 7:41 ` Yoshihiro Shimoda 2016-06-21 2:30 ` Yoshihiro Shimoda 2016-06-21 2:30 ` Yoshihiro Shimoda 2016-06-21 7:21 ` Felipe Balbi 2016-06-21 7:21 ` Felipe Balbi 2016-06-20 11:49 ` Peter Chen 2016-06-20 11:49 ` Peter Chen 2016-06-20 12:08 ` Felipe Balbi [this message] 2016-06-20 12:08 ` Felipe Balbi 2016-06-21 6:05 ` Peter Chen 2016-06-21 7:26 ` Felipe Balbi 2016-06-21 7:26 ` Felipe Balbi 2016-06-21 9:07 ` Peter Chen 2016-06-21 9:07 ` Peter Chen 2016-06-21 10:02 ` Felipe Balbi 2016-06-21 10:43 ` Tony Lindgren 2016-06-21 10:43 ` Tony Lindgren 2016-06-21 10:56 ` Felipe Balbi 2016-06-21 13:05 ` Peter Chen 2016-06-21 13:05 ` Peter Chen 2016-06-22 6:56 ` Felipe Balbi 2016-06-22 6:56 ` Felipe Balbi 2016-06-22 7:33 ` Peter Chen 2016-06-22 8:03 ` Felipe Balbi 2016-06-22 7:49 ` Roger Quadros 2016-06-22 7:49 ` Roger Quadros 2016-06-22 8:14 ` Felipe Balbi 2016-06-22 8:30 ` Roger Quadros 2016-06-22 8:30 ` Roger Quadros 2017-01-19 11:56 ` Vivek Gautam 2017-01-19 12:15 ` Roger Quadros 2017-01-19 12:15 ` Roger Quadros 2017-01-19 15:15 ` vivek.gautam 2017-01-20 8:30 ` Roger Quadros 2017-01-20 8:30 ` Roger Quadros 2017-01-20 11:39 ` Vivek Gautam 2016-06-23 7:42 ` Yoshihiro Shimoda 2016-06-23 7:42 ` Yoshihiro Shimoda 2016-06-10 13:07 ` [PATCH v10 09/14] usb: of: add an API to get OTG device from USB controller node Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-13 8:13 ` Jun Li 2016-06-13 8:13 ` Jun Li 2016-06-13 8:16 ` Roger Quadros 2016-06-13 8:16 ` Roger Quadros 2016-06-13 8:23 ` [PATCH v11 " Roger Quadros 2016-06-13 8:23 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 10/14] usb: otg: add hcd companion support Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 11/14] usb: otg: use dev_vdbg() instead of VDBG() Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 12/14] usb: hcd: Adapt to OTG core Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-14 8:17 ` Roger Quadros 2016-06-14 8:17 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 13/14] usb: gadget: udc: adapt " Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-12 11:36 ` Peter Chen 2016-06-12 11:36 ` Peter Chen 2016-06-13 7:14 ` Roger Quadros 2016-06-13 7:14 ` Roger Quadros 2016-06-13 7:20 ` Peter Chen 2016-06-13 7:20 ` Peter Chen 2016-06-13 7:37 ` Roger Quadros 2016-06-13 7:37 ` Roger Quadros 2016-06-13 7:40 ` Peter Chen 2016-06-13 7:40 ` Peter Chen 2016-06-13 7:55 ` [PATCH v11 " Roger Quadros 2016-06-13 7:55 ` Roger Quadros 2016-06-13 7:56 ` Peter Chen 2016-06-13 8:06 ` Roger Quadros 2016-06-13 8:06 ` Roger Quadros 2016-06-10 13:07 ` [PATCH v10 14/14] usb: host: xhci-plat: Add otg device to platform data Roger Quadros 2016-06-10 13:07 ` Roger Quadros 2016-06-14 8:18 ` Roger Quadros 2016-06-14 8:18 ` Roger Quadros 2016-06-14 2:17 ` [PATCH v10 00/14] USB OTG/dual-role framework Peter Chen 2016-06-14 8:12 ` Roger Quadros 2016-06-14 8:12 ` Roger Quadros 2016-06-16 11:07 ` Roger Quadros 2016-06-16 11:07 ` Roger Quadros 2016-06-17 7:17 ` Felipe Balbi 2016-06-17 7:17 ` Felipe Balbi 2016-06-17 7:31 ` Roger Quadros 2016-06-17 7:31 ` Roger Quadros
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